Although lithium-ion batteries are widely adopted, their safety remains a critical bottleneck that limits further technological advancement. This study investigates how anode materials influence the thermal runaway pathways of ternary pouch cells by examining the safety responses of graphite and lithium metal anodes under nail penetration and external short-circuit conditions. By simultaneously monitoring key parameters, including temperature, voltage, current, and analyzing electrode interface morphology and contact status, this study demonstrates that anode properties fundamentally affect failure mechanisms during thermal events. In external short-circuit tests, the highly reactive lithium metal anode, together with powdery lithium deposits formed after cycling, exacerbates exothermic side reactions, resulting in significantly higher peak currents (148.7 A vs. 100.9 A) and maximum temperatures (273 ℃ vs. 104 ℃) than those observed with graphite anode, indicating a substantially greater risk of thermal runaway. Conversely, lithium metal anodes exhibit superior safety performance during nail penetration tests. Localized melting at the penetration site, along with subsequent physical detachment and rapid chemical passivation, leads to a sharp increase in contact resistance (>40 Ω), which effectively interrupting interrupts the internal short circuit and prevents thermal runaway. In contrast, the rigid structure of graphite anodes maintains the short-circuit pathway, causing rapid heat accumulation, with peak temperature rates exceeding 420 ℃/s. Overall, this study reveals the structure-property-failure relationship between anode materials and their associated thermal behaviors, providing valuable insights for the design of lithium batteries that combine high energy density with enhanced safety through targeted anode modification.

Gallium (Ga), as a liquid metal with negative mixing enthalpies with multiple elements, can form high-entropy alloys (HEAs) with various metals under mild conditions. In this study, Ga was introduced into C14 Laves phase HEAs. (Ti_0.9Zr_0.1)_1.1Mn_1.2-x Cr_0.8Ga _x alloys (x = 0, 0.1, 0.2) alloys were fabricated using vacuum induction melting technology. Through a combination of theoretical calculations and experimental tests, the effects of the Ga substitution for Mn on the microstructure and hydrogen storage properties were systematically investigated. Theoretical calculations revealed that Ga doping reduced the atomic size difference from 7.54 to 7.39 and lowered the mixing enthalpy to -9.17 kJ/mol, thereby improving the phase stability. The valence electron concentration analysis suggested an efficient hydrogen absorption/desorption performance at ambient temperature. The experimental results demonstrated that all alloys exhibited single-phase C14 Laves structures with a homogeneous elemental distribution. Ga substitution for Mn increased the unit cell volume from 165.52 ų to 167.25 ų, significantly reducing the hydrogen absorption/desorption plateau pressures and hysteresis factors while improving the kinetic performance. The time required to reach 90% of the maximum hydrogen capacity was shortened to less than 50 s. Among the tested alloys, (Ti_0.9Zr_0.1)_1.1Mn_1.1Cr_0.8Ga_0.1 displayed the optimal hydrogen storage properties, achieving a maximum capacity of 1.81% (weight fraction) with absorption/desorption plateau pressures of 0.9 MPa and 0.86 MPa at 293 K, respectively. This alloy retained 96% of its initial capacity after 30 cycles while maintaining a single C14 Laves phase, demonstrating exceptional cycling stability. This study clarifies the mechanistic role of Ga in high-entropy hydrogen storage alloys and provides theoretical guidance for Ga applications in hydrogen storage materials.

Traditional battery thermal management structure that integrates a phase change material (PCM) with air cooling—using "X"-shaped fins and copper columns—can significantly improve the heat dissipation efficiency of air cooling and meet the temperature requirements of batteries under harsh conditions. However, these structures still exhibit notable deficiencies in heat dissipation efficiency. To address these issues, we propose a novel and innovative "dissipation-storage-integrated" thermal management structure that effectively combines PCM and air cooling. This study investigates the thermal characteristics of the proposed structure during repeated charge-discharge cycles, in which the batteries discharge at a relatively high rate of 6 C and charge at 2 C under challenging high-temperature conditions. The effects of the PCM physical parameters (e.g., melting point, thermal conductivity, and specific heat capacity) and different cold-plate structural parameters (e.g., thickness, shape, and fin density) are analyzed to evaluate their influence on the heat transfer characteristics of the structure. The results demonstrate that the proposed battery thermal management structure is highly effective. It can successfully maintain the maximum temperature of a single battery cell within a safe range of 45 ℃ and limit the maximum temperature difference to within 3 ℃ throughout multiple charge-discharge cycles. Among PCM parameters, the melting point strongly influences the battery temperature rise. An excessively high melting point inevitably leads to an overly high maximum battery temperature, jeopardizing the battery's performance and lifespan. In contrast, an excessively low melting point causes PCM to melt alarmingly fast. As a result, the PCM-based cold-plate lacks the essential temperature-regulating capacity in the later part of the cycle, significantly accelerating the battery temperature rise. Provided that PCM does not completely melt, lowering the melting points is more favorable for maintaining safe operating temperatures. Additionally, increasing the thickness of the PCM cold-plate, cold-plate panel, and the fin ribs can significantly enhance the heat dissipation performance and temperature-control stability of the structure, further improving the overall efficiency of the thermal management system. These findings provide valuable methodological support for designing battery thermal management systems that ensure the safety of lithium-ion batteries under long-distance continuous high-speed driving conditions and in cold regions. The proposed approach not only strengthens the theoretical foundation of battery thermal management but also provides practical and valuable guidance for improving the performance and safety of battery systems in demanding application scenarios.

Lithium dendrite growth is ubiquitous in lithium-metal batteries and severely affects their service life, efficiency, and safety. In recent years, Solid-state batteries have become the main research focus in the field of new energy vehicle batteries in recent years due owing to their high safety, cycling stability, and energy density as well as long cycle life. These batteries can more effectively inhibit dendrite growth compared with liquid-state batteries because of the higher density of solid-state electrolytes; however, complete inhibition remains challenging. Studies have shown that external conditions (e.g., temperature, boundary pressure, voltage) and electrochemical parameters (e.g., anisotropy intensity, interfacial mobility, barrier height) influence dendrite growth. The inhibitory effects of nanoskeletons and artificial separators are key issues. For nanoskeletons, the nanotube array's tube length and intertube gap, as well as the volume fraction of porous skeletons in multihierarchical structures, were identified as key variables inhibiting dendrite growth. For artificial separators, a double-layer porous architecture reduces lithium dendrite height by regulating lithium-ion transport. Herein, using a phase-field model with coupled mechanical-thermal-electrochemical fields, we analyze how nanoskeleton and separator morphologies inhibit dendrites. In our model, the primary dendrite backbone height decreases by 16.62% and 21.04% for nanotube-array and hierarchical/multilevel nanoskeletons, respectively. With increasing roughness and uneven distribution, the maximum dendrite height increases by 17.87% and 25.57% in these two skeletons, respectively. Increasing separator thickness and decreasing porosity inhibit dendrite growth; however, thickening from 0.2 to 0.4 μm only marginally improves the inhibition effect. Joint optimization of thickness and pore spacing enhances suppression: at 0.4 μm thickness with 0.4 μm pore spacing, dendrite height decreases by 17.70%, whereas at 0.2 μm thickness with 0.5 μm spacing, it decreases by 6.95%. Relative to optimizing the thickness alone, the combined optimization further reduces dendrite height by 10.75%. In this model, modifying the cross-sectional morphology reduces dendrite height by 12.75%.

All-solid-state sodium batteries hold significant promise for large-scale energy storage due to their potential cost-effectiveness and safety. However, their practical application is limited by the high interfacial impedance between the solid electrolytes and sodium metal anode, as well as the risks of sodium dendrite growth. In this study, an In₂S₃ interfacial layer is introduced on the Na_3.4Zr_1.9Zn_0.1Si_2.2P_0.8O₁₂ (NZZSPO) solid electrolyte via magnetron sputtering. This layer reacts in situ with the sodium metal anode to form a Na–In alloy/Na₂S interlayer at the NZZSPO/Na interface. The Na-In alloy/Na₂S interlayer improves the wettability at the solid electrolyte-anode interface, reduces the interfacial impedance, and significantly enhances the ability of the NZZSPO@In₂S₃ solid electrolyte to suppress sodium dendrite formation. The experimental results show that the critical current density of a symmetric battery based on the NZZSPO@In₂S₃ solid electrolyte is enhanced significantly, increasing from 2.6 to 8.2 mA/cm² at 60 ℃ and from 1.6 to 2.2 mA/cm² at room temperature. Moreover, the Na|In₂S₃@NZZSPO@In₂S₃|Na symmetric battery exhibited excellent cycling stability for 2000 h at 60 ℃ and 5 mA/cm². Even at room temperature, the battery can also operate stably at 1.5 mA/cm² for 1500 h. Additionally, the Na₃V₂(PO₄)₃|NZZSPO@In₂S₃|Na all-solid-state battery delivers an initial discharge capacity of 108.6 mAh/g at 0.1 C with a Coulombic efficiency of 95.4% and capacity retention of 94.8% after 100 cycles. Even at a higher current density of 1 C, the battery still demonstrates a capacity retention of 88.8% after 1000 cycles. This study provides an in situ approach for constructing a Na-In/Na₂S interlayer at the NZZSPO/Na interface, significantly enhancing the ability of the solid electrolyte to suppress sodium dendrite growth and offering a promising strategy for developing high-performance all-solid-state sodium batteries.

Lithium-ion batteries (LIBs) are widely used in portable electronic devices, electric vehicles, and large-scale energy storage systems due to their high energy density, long cycle life, and environmental friendliness. However, conventional liquid electrolytes can promote lithium dendrite growth during cycling, leading to internal short circuits, accompanied by side reactions and interfacial instability-severely compromising both safety and longevity of LIBs. Polymer-based composite solid-state electrolytes have emerged as promising candidates for constructing high-safety lithium metal batteries. However, their conventional fabrication methods often require high-temperature or extended thermal curing processes, limiting their scalability and practical deployment. In this study, we present a novel UV-curing-based fabrication route for the rapid construction of a composite solid-state electrolyte membrane, denoted as OICSE-Al₂O₃-1, composed of ethoxylated trimethylolpropane triacrylate doped with aluminum oxide (Al₂O₃) nanoparticles. The experimental results reveal that the addition of Al₂O₃ effectively suppresses the formation of crystalline domains within the polymer matrix, thereby enhancing the ionic conductivity. Specifically, OICSE-Al₂O₃-1 achieves an ionic conductivity of 5 × 10^-4 S/cm at 30 ℃, while also modulating the polymer chain alignment and optimizing the distribution of ion-conducting channels, which facilitates efficient lithium-ion transport (with a lithium-ion transference number t_{\mathrm{L}{\mathrm{i}}^{+}} of 0.66). Furthermore, the addition of Al₂O₃ broadened the electrochemical stability window to 5 V and significantly improved the cycling stability of the electrolyte. At a discharge rate of 0.5 C, OICSE-Al₂O₃-1 retained 89.3% of its initial capacity after 200 cycles. It also demonstrates stable lithium plating/stripping behavior over 1300 h at a current density of 200 μA/cm². Moreover, this study presents an efficient, room-temperature fabrication strategy for quasi-solid-state electrolytes, extending their potential applications in advanced energy storage technologies.

The rapid development of renewable energy technology has led to the increased application of lithium batteries as efficient energy storage devices in electric vehicles, as well as aerospace and military equipment. However, these batteries exhibit significantly decreased performance at low temperatures, mainly because of decreased ionic conductivity, intensified lithium-dendrite growth, and increased interfacial side reactions, which severely limit their applications in extreme-temperature scenarios. Electrolytes, as essential components for lithium-ion transportation, play a key role in expanding the electrochemical stability window, inhibiting side reactions, and optimizing battery performance. In this review, the failure mechanism and multidimensional collaborative-optimization design of low-temperature electrolytes are systematically reviewed to offer theoretical guidance for the design of high-performance low-temperature electrolytes. The causes of electrolyte failures at low temperature are explored from three perspectives: ion transportation, electrode-electrolyte interface properties, and solvation structure. Subsequently, recent strategies for regulating the electrolyte components of lithium batteries are reviewed based on three categories: solvent, conductive lithium salt, and additives. Thereafter, a novel low-temperature electrolyte, which mainly comprises a weak-solvent electrolyte, an ionic-liquid electrolyte, a liquefied-gas electrolyte, and a local high-concentration electrolyte, is developed. The results reveal that an adjustment of the electrolyte composition improves ionic conductivity, inhibits dendrite growth, and enhances low-temperature battery performance, demonstrating one of the simplest and effective strategies for solving the aforementioned issues. Finally, the directions for future related studies are proposed.

To address the heat dissipation challenge of submerged cooling for soft-pack battery modules under high-rate discharge, a submerged cooling experimental platform was constructed for 3S2P 32 Ah soft-pack battery module using Shell SK-3 as the cooling medium. A three-dimensional thermal evaluation system was used to analyze the cooling effect based on the temperature increase of the battery, the standard deviation of the temperature differences between cells, and overall temperature uniformity. First, a comparative experiment between static and flow-immersion cooling was conducted. Then, the effects of the discharge rate, coolant flow rate, and cell spacing on the cooling effect of the flow-immersion system were studied. The experimental results show that the static cooling system can maintain the temperature of the battery within safe limits up to a 3C discharge rate, while appropriately configured flow-immersion cooling can extend the effective temperature control range to a 5C discharge rate. Compared with natural air convection, the static submerged cooling system reduced the battery surface temperature by 29.79 ℃, and the flow-submerged cooling system achieved an additional 8.26 ℃ reduction, lowering the temperature difference between cells by 60.2%. The analysis of the experimental data revealed that at low coolant flow rates, simply increasing the cell spacing had a minimal effect. Conversely, with a small cell spacing, increasing the flow rate alone worsened the temperature uniformity. Additionally, the correlation analysis of Gr/Re² and h indicated that the combined effects of the internal spacing size of the battery pack and the flow rate of the cooling medium ultimately affect the temperature distribution characteristics of the battery pack by influencing the intensity ratio of natural convection to forced convection. For example, the inhomogeneity of forced convection can cause a large temperature difference between cells, suggesting that natural convection can be used to optimize the temperature consistency of the system design. Finally, the evaluation indexes, such as volumetric energy density, group efficiency, and heat dissipation effect, were compared with other cooling methods reported in the literature, confirming the superior performance and strong engineering application value of the flow-immersion cooling system.

Lithium-ion battery (LIB) thermal runaway proceeds rapidly and violently representing a significant challenging in the field of energy-storage safety, as it can initiate thermal propagation within energy storage systems and lead to losses. To meet the timeliness requirements for early warning of overcharge-induced thermal runaway in LIBs, an early warning method integrating the temporal pattern attention (TPA) mechanism, bidirectional long short-term memory (BiLSTM) network, and isolation forest algorithm is proposed. In this method, the changing patterns of battery-state characteristics across multiple time steps are first captured using TPA, which applies differentiated weighting to focus on the mostvaluable information. Subsequently, the bidirectional neural network structure of BiLSTM is used to extract bidirectional information from battery-characteristic data, thus enhancing the prediction accuracy of the model. Finally, by integrating the isolation forest algorithm, the real battery dataset is used to establish an isolation forest model, which calculates the anomaly scores of battery-state characteristics. Thereafter, the battery states are classified by selecting the optimal anomaly score threshold, enabling early warning of abnormal battery conditions. The experimental results reveal that the proposed method achieves an F1 score of 0.9509 and can provide early warning of abnormal battery conditions 7 s before overcharge-induced thermal runaway; this time is 252 s earlier than that of the temperature threshold method. Overall, the method demonstrated here offers insights into enhancing the accuracy and timeliness of early warning for overcharge-induced thermal runaway in LIBs.

With the continuous improvement in the energy density of commercial and industrial energy storage systems and the expanding range of applications, coupled with stringent thermal management requirements under high-temperature and high-humidity conditions, the potential risk of thermal runaway has become increasingly significant. However, experimental research on liquid cooling system performance in such thermo-humidity environments remains limited. This study investigates the operational characteristics and energy consumption of cooling source equipment, supply-return liquid temperatures in distribution systems, as well as cold plate surface and battery temperatures under continuous charge-discharge conditions in high-temperature/high-humidity environments (40 ℃/30% RH, 30 ℃/30% RH, and 30 ℃/70% RH). Results demonstrate that, compared with 40 ℃/30% RH and 30 ℃/30% RH conditions, the start-stop frequency of compressors and fans decreased by 52%, total cooling system energy consumption increased by 28%, and the longitudinal weighted average battery temperature difference was reduced from 3.14 ℃ to 2.82 ℃. Under high-humidity conditions (30 ℃/70% RH), when the supply liquid temperature was increased from 20—25 ℃ to 24—28 ℃, system energy consumption decreased by 22%, with the maximum battery cell temperature rising by 3 ℃. The average maximum temperature difference decreased by 22.56%, and the longitudinal average temperature difference was reduced from 2.89 ℃ to 2.80 ℃. Ambient temperature, humidity, and supply liquid temperature showed no significant impact on the longitudinal temperature difference across battery cells within the pack.

With the rapid development of renewable energy, energy storage systems (ESSs) play increasingly vital roles in balancing energy supply and demand, as well as enhancing energy-utilization efficiency. Sodium-ion battery (SIB) ESSs, due to their unique advantages, are rated among the most promising candidates for large-scale energy storage. However, the heat generated by SIBs during charging and discharging can significantly impact their performance, lifespan, and safety. Therefore, more efficient thermal-management strategies must be developed to improve SIB ESS safety. In this study, experiments and numerical simulations are combined to explore the asymmetric heat-generation characteristics of SIBs during charging and discharging, as well as propose a multistage variable flow-rate thermal-management-optimization strategy during discharging. The experimental results reveal that the heat-generation during the discharging process of SIBs is three times that of their charging process, with a peak heat-generation power of 70 W under 1P discharge conditions. Conversely, under the 1P charging conditions, the peak heat-generation power is only 25 W and lasts for a very short period. Further, an asymmetric liquid-cooling thermal-management system is introduced for SIB charging and discharging processes, and a multistage variable flow-rate optimization strategy is proposed based on the characteristic of stage-wise changes in the heat-generation power during discharging. This strategy effectively reduces the power consumption of the thermal-management system while maintaining the same battery temperature. The insights obtained from this study can be used to optimize the power consumption of SIB thermal-management systems as well as enhance the safety of SIB ESS.

A steam-generation system integrating a cascade high-temperature heat pump with a vapor-compression machine is presented in this study. The system utilizes R134a, R245fa, and R718 refrigerants as working fluids for the low-temperature, high-temperature, and steam stages, respectively. Based on the dynamic optimization of intermediate conditions, the thermodynamic performance of the system is investigated at environmental temperatures ranging from -15 ℃ to 40 ℃ and steam-outlet temperatures from 140 ℃ to 170 ℃. Thereafter, an experimental platform is constructed to validate the simulation data. The results, based on the dynamic optimization model, reveal that as the intermediate-steam temperature increases, the spray rate decreases, and the optimal low-temperature-stage condensation temperature increases. At a steam-outlet temperature of 170 ℃, the system coefficient of performance (COP) increases from 1.183 to 1.914 as the environmental temperature rises from -15 ℃ to 40 ℃. At an environmental temperature of 20 ℃, as the steam-outlet temperature increases from 140 ℃ to 170 ℃, the system COP decreases from 1.945 to 1.657, whereas the steam output increases from 0.856 to 1.170 t/h. The experimental results reveal that at a steam outlet temperature of 170 ℃ and environmental temperatures between 23 ℃ and 27 ℃, the system COP and total power are 3%—5% and 8%—12% lower than the theoretical values, respectively. Error analysis of the simulation and experimental performance indicators reveals that the largest errors are concentrated in the cascade heat pump power (13.29%) and total power (10.01%).

Efficient regulation of charging parameters in borehole thermal energy Sstorage (BTES) systems is crucial for ensuring system efficiency and long-term stability. This study investigates the influence of key operational variables and intermittent start-stop strategies on thermal storage efficiency during the charging phase. A full-scale, three-dimensional transient simulation model is developed and validated using field data from a BTES demonstration project at Shenyang Jianzhu University, where initial ground temperature and soil thermal conductivity were 10.94 ℃ and 1.72 W/(m·K), respectively. The analysis examines the influence of inlet flow velocity, inlet temperature, and intermittent operation patterns on the heat storage process. Results reveal four primary findings: (1) The heat exchange ratio per borehole depth between double U-tubes and single U-tubes decreases from 2 to 1.4 over time, indicating that the structural advantage of double U-tubes diminishes with prolonged thermal storage. (2) As inlet flow velocity increases (0.07—1 m/s), the temperature difference between U-tube inlet and outlet declines, with double U-tubes exhibiting lower temperature differences than single U-tubes due to thermal short-circuiting effects. Optimal flow velocity ranges for single and double U-tubes are determined as 0.4—0.6 m/s and 0.2—0.4 m/s, respectively, based on the ratio of heat transfer to pressure drop. (3) Increasing the fluid inlet temperature from 30 ℃ to 80 ℃ elevates the soil temperature around the borehole, expanding the thermal influence radius from 0.4 to 0.85 m (a 112.5% increase). Heat exchange capacity and temperature difference exhibit linear growth with rising inlet temperature. (4) When the start-stop time ratio increases from 1 to 2, soil temperature at r = 0.2 m rises from 26.62 ℃ to 29.81 ℃, while recovery rate decreases from 17.53% to 7.65%. Intermittent operation reduces total heat storage by 13.38%—26.31% compared to continuous operation but improves heat exchange efficiency by 29%—47%, demonstrating its effectiveness in mitigating thermal accumulation and enhancing storage efficiency. These findings provide theoretical and practical insights for optimizing BTES operational strategies, supporting the design of more efficient seasonal thermal energy storage systems in cold regions.

With the integration of renewable energy sources such as distributed photovoltaics, traditional frequency regulation resources can no longer meet the growing frequency regulation demand. To better improve the frequency characteristics of power grids and unleash the frequency regulation potential of distributed photovoltaics, we propose an optimization control method for distributed photovoltaic primary frequency regulation considering energy storage SOC. First, a grid-connected frequency control model was developed based on the frequency response characteristics of distributed photovoltaic and energy storage devices. Second, combined with the Guanhao pig optimization algorithm, the key parameters of the predictive control model were adaptively adjusted. Based on this, considering the capacity limitation of distributed photovoltaics and the characteristics of energy storage SOC, a frequency modulation parameter optimization model was developed, and the state space equation was updated in real time to achieve precise control of the frequency support capability of distributed photovoltaics. Finally, by comparing the frequency modulation performance under different control strategies through MATLAB/Simulink simulation examples, the results show that the optimized control algorithm has higher control accuracy and faster response speed than the pre-optimized control strategy. Moreover, the optimized algorithm demonstrates good control performance in delay scenarios with good robustness and anti-interference ability.

With the advancement of energy transition, the power system is facing challenges in supply-demand balance. This paper analyzes the current challenges faced by the power system and the development status of demand response, power metering, and energy storage systems, describes the necessity and importance of constructing a collaborative optimization model for power metering and energy storage based on demand response, and introduces in detail the model's construction ideas, key technologies, and specific implementation steps. It also discusses the application scenarios and expected effects of the model in actual power systems, providing theoretical support and practical references for promoting the power system towards a more efficient, intelligent, and sustainable direction.

With the rapid development of smart grids, the role of energy storage systems has become increasingly prominent. This paper discusses how to optimize smart grid energy storage systems using big data technologies, analyzes the current application status of big data in energy storage systems—including data collection, storage, and processing—and introduces optimization strategies for energy storage systems based on big data analysis, such as capacity configuration optimization, charging/discharging strategy optimization, operation status monitoring, and fault diagnosis. It also elaborates on the challenges encountered in these optimization strategies and prospects the future development trends.

Under the "dual carbon" goals, renewable energy-based hydrogen production has become a key pathway to advance the transition toward a low-carbon, clean, and efficient energy system. However, grid-connected hydrogen production faces challenges such as limited renewable energy accommodation and mismatches between hydrogen production efficiency and operational economics. This study develops a multi-objective optimization model to minimize the levelized cost of hydrogen (LCOH) and maximize the grid-feed-in ratio of renewable energy, hydrogen yield, and equivalent full-load hours of the electrolyzer. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is employed to generate a Pareto solution set, and the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method with entropy-based weights is applied to identify the optimal configuration. A comparative analysis is performed with and without an energy storage system. Results show that the grid-connected hydrogen production system with energy storage achieves a grid-feed-in ratio of 5.78%, a hydrogen yield of 2899.3 tons, and a curtailment ratio of 6.49% relative to total renewable generation. In contrast, the system without energy storage records a higher grid-feed-in ratio of 6.84%, a lower hydrogen yield of 2771.82 tons, and a curtailment ratio of 11.34%. These findings demonstrate that energy storage effectively reduces grid feed-in and curtailment, thereby enhancing hydrogen production. Furthermore, the operational characteristics of the optimized system on four representative days—vernal equinox, summer solstice, autumnal equinox, and winter solstice are examined. Results indicate that integrating energy storage not only mitigates renewable energy fluctuations but also reduces electrolyzer load variability, thereby improving intra-day operational stability and renewable energy utilization. This study provides theoretical support and engineering reference for the optimal configuration of grid-connected hydrogen production systems.

In response to the challenges of absorbing green power caused by the variability of wind and solar resources, the limited efficiency of conventional water electrolysis methods for hydrogen production, and the high costs associated with H₂ storage and transportation, this paper proposes a solid oxide cell (SOC)-based hydrogen storage and electricity-heat-gas multienergy coupling optimization model incorporating a hydrogen-doped natural gas pipeline network. A dynamic coupling model is constructed, encompassing wind power, photovoltaic systems, heating systems, SOC hydrogen storage, and hydrogen-doped transportation systems. With green power utilization rate, cost-effectiveness, and carbon reduction as key optimization objectives-and considering the uncertainty of renewable energy output, energy balance constraints for electricity and thermal gas, and operational limitations of H₂ production, storage, and transportation-integrated optimization is used to obtain the optimal solution. A simulation experiment was conducted on a multienergy flow cycle system involving electricity and thermal energy in a specific park in Xinjiang, where the annual abandoned wind and solar power totaled 11520 MWh). The results demonstrated that the SOC-based hydrogen energy storage system can achieve 100% utilization of renewable power, reducing annual operating costs by ¥2.14 million and carbon emissions by 1068 tons compared to conventional energy storage methods (battery and thermal storage). By optimizing the electric-to-thermal ratio coefficient of combined heat and power, the electrolysis efficiency of SOCs increased to 85%, while the waste heat utilization rate reached 90%, thereby maximizing of the driving force for water electrolysis. At a 30% volume mixing ratio, the natural gas consumption in the hydrogen-doped pipeline network decreased by 23%, the total system cost was reduced by over 50%, frictional pressure loss in the pipeline was minimized, node pressure improved, and overall transportation capacity significantly enhanced. The return on investment was substantially improved, offering valuable insights for large-scale renewable energy integration and facilitating efficient, cost-effective, long-distance, and safe H₂ transport.

Large-capacity shaft-type gravity energy storage (GES) systems are effective tools for long-term energy storage. For applications requiring direct grid connection owing to the transient support characteristics of motors, graded heavy blocks are feasible tools for achieving flexible power regulation in shaft-type GES systems. However, megawatt (MW)-level hundred-ton heavy-block energy storage systems exhibit significant power intermittency, and MWh-capacity GES systems require numerous heavy blocks. Thus, the grading of these heavy blocks, as well as their storage and transportation, becomes critical issues in system operation. To address these challenges, this study proposes a solution that considers the graded storage and optimal path transportation of heavy blocks. First,a weight limit is used to divides the mass of the heavy blocks into four grades based on the adjustable maximum power of battery packs and energy storage, with the total number of blocks per grade being determined by the typical daily sunlight duration. Second, the storage area is designed to maximize space utilization. Based on thislayout, and considering the transportation time and constraints on the number of blocks, the Dijkstra algorithm is used to design the shortest possible routes for transporting the heavy blocks. Thereafter, the total storage area for the heavy blocks is divided into sections, after which four automated guided vehicles (AGVs) are employed for coordinated transportation. The minimum acceleration requirements for these AGVs are then derived to ensure efficient operation. Finally, the effectiveness of large-scale storage and transportation of a 100 MWh GES system is verified using typical daily net load power-fluctuation smoothing.

Compressed carbon dioxide (CO₂) energy storage, as a representative direction for novel long-term energy storage, is an effective strategy for smoothing the high volatility of renewable electricity. To resolve the limited heat sources and application potential of existing adiabatic compressed CO₂ energy storage systems (ESSs), which result in decreased economic gains, a gas-liquid-interconversion compressed CO₂ ESS, which is driven by waste heat from the ethylene process, is proposed. This system utilizes low-grade waste heat from the ethylene process for the gasification of liquid CO₂ and the absorption of heat from the gasified CO₂ in its energy-release section. Additionally, it uses a proportion of the high-grade recovered heat from its energy-storage section to produce industrial steam, thereby enhancing heat utilization and the benefits of the ESS. Performance and economic sensitivity analysis under different operating conditions reveal that its power-generation capacity and energy-storage density decrease when most of the recovered heat is mainly used to generate industrial steam. However, the overall system cycle gain is significantly enhanced by steam-output profits. Additionally, when the compressed heat is mainly used to supply power to the energy-release section of the system, its power-cycle efficiency improves significantly, although the system gain is significantly impacted by the electricity-price difference, favoring regions with high electricity-price variability.

In the context of the global energy transition, the strategic development of the energy storage industry is of great significance to optimizing the national energy structure, supporting high-quality economic growth, and achieving the goals of carbon peaking and carbon neutrality. Based on a review of relevant literature, this paper summarizes the views of various experts on the current state and future development of the new energy storage industry and presents a detailed overview of the hierarchy and functions of the energy storage industry chain. It reviews the key challenges facing the industry, including the lack of comprehensive safety prevention and control technologies, insufficient industrial coordination, inadequate integration, and limited market demand. The study analyzes the important role of a digital intelligent platform in advancing industry development and introduces its fundamental framework. On this basis, a new development model of the energy storage industry chain driven by a digital intelligent platform is proposed. This model emphasizes (1) the innovation path of full-process safety technologies under platform empowerment, (2) the platform-driven "energy storage + safety" industrial integration pathway, and (3) the pilot platform-led market expansion pathway. These three development strategies aim to enhance enterprise collaboration, promote industrial integration, stimulate market demand, and strengthen innovation capacity. A comprehensive analysis suggests that the platform-driven development model and the "technology innovation-industrial integration-market expansion" path are conducive to deepening enterprise cooperation, integrating the energy storage sector with the fire safety and information technology industries, and achieving dynamic safety control throughout the entire life cycle of the storage system. This model offers a new path reference point for technological innovation, industrial transformation, and the commercialization of energy storage technologies. Furthermore, the application of rapidly evolving large language models into digital intelligent platforms is expected to promote cross-industry integration, elevate industrial intelligence, and boost the core competitiveness of the energy storage sector.

The wide application of chemical energy storage system has brought important grid power resources and provided an important guarantee for the upgrading of the national grid, but its own network security problems also need to be properly solved. This research analyzes and summarizes the security issues of chemical energy storage network under big data. Firstly, it mainly summarizes the research progress of chemical energy storage system at this stage, including the types of mainstream chemical energy storage systems and the application of chemical energy storage in power system; Then the internal structure of the current conventional chemical energy storage system is analyzed, including the energy storage battery management system, the boost converter system and the energy management system (EMS). Finally, combined with the big data technology, the solution strategy and development direction of the network security problem of the chemical energy storage system are discussed, hoping to provide some ideas for the future research of the chemical energy storage system.

As nations increasingly emphasize maritime interests and the demand for deep-sea operations grows, it is necessary to address the endurance, extreme environments, and complex operational conditions of manned and unmanned ships, boats, submarines, robots, pre-positioned sensors, and other equipment operating both on the surface and underwater. In particular, the enhanced power supply requirements for battlefield energy integration-such as high-load rapid maneuvering, ultra-long endurance, and extended pre-positioning-necessitate the development of an integrated "acquisition-storage-transmission-networking" regional energy system tailored to maritime combat platforms. Such a system would enable rapid replenishment of surface and underwater energy resources or establish an efficient, rapid-response guarantee strategy supported by advanced power distribution networks. Currently, electro-energy technologies widely applied to maritime combat platforms include chemical batteries for platform power supply, long-range reserve power sources, large-scale pre-positioned underwater energy storage, mechanical energy conversion in marine environments, solar energy conversion in marine environments, bioenergy conversion in marine environments, and underwater electro-energy support networks. In recent years, with the rapid advancement of chemical batteries, wireless energy transmission, solar energy, wave energy, biomass energy, and nuclear energy, the trend toward integrated electro-energy networks for surface and underwater applications has become increasingly evident. Therefore, to identify advanced and better-suited energy acquisition, transmission, storage, and networking technologies that can effectively support the iterative upgrading and innovative application of maritime combat power energy security, this paper systematically reviews the latest developments in these fields. It summarizes current technological levels, capabilities, and critical challenges requiring breakthroughs, while also analyzing prospects for constructing an integrated surface-underwater maritime combat energy security system.

Liquid air energy storage (LAES) technology has garnered considerable attention because of its unique advantages in enhancing grid stability. At present, the successful commissioning of several demonstration projects has validated the feasibility and broad application prospects of LAES technology. This study first introduces the basic principles and operating mechanisms of LAES. Then, it reviews the latest research advancements in this technology across various applications, including independent, coupled, and multi-output systems. Notably, the coupling of LAES technology with other energy systems, such as liquefied natural gas regasification and industrial waste heat usage, demonstrates substantial multi-energy conversion advantages, achieving efficient electricity, cooling, and heating integration. In the future, LAES technology is expected to continue evolving toward improved system cycle efficiency, optimized energy density, and reduced costs. Further, the integration of LAES with other energy systems through multi-energy coupling modes will promote large-scale power system applications. LAES is anticipated to play a crucial role in peak shaving, frequency modulation, and smoothing renewable energy outputs, thereby serving as a key technology supporting the transition to a low-carbon energy system.

With the increasingly serious fossil energy crisis and environmental pollution problems, building a clean, low-carbon, safe and efficient energy system has become an inevitable trend for future development. Solar energy resources, as a clean and renewable energy source, have been widely applied in distributed photovoltaic power generation systems at present. This article first elaborates on the application value of this system. Then, the constraints on the optimal configuration and operation of the system were analyzed, involving the economy of photovoltaic systems, the impact of energy storage systems on stability, and the role of power market policies and fluctuations. Finally, the optimization paths were discussed, aiming to enhance the economic efficiency, stability and environmental benefits of the system through technical means, providing a reference for the efficient application of distributed photovoltaic energy storage systems.

The coordinated operation of photovoltaic power generation system and energy storage device makes it possible to realize the grid-connected photovoltaic. With the development of solar energy resources, the fluctuation of photovoltaic power generation gradually appear, and become a key factor affecting the grid connected. Coupling the energy storage device with the photovoltaic power generation system helps to achieve the balance between supply and demand of the power side and the load side, and also lays the foundation for the efficient and stable operation of the power system. Starting from the coordinated operation relationship between photovoltaic power generation system and energy storage device, the advantages of photovoltaic-energy storage integration mechanism in power system are analyzed, and optimization strategies are proposed for the aspects of power, intelligent management, capacity allocation, voltage, etc., aiming to provide effective reference for the development of new energy resources.

Driven by the national dual-carbon goals, the rapid development of new energy industries has led to the widespread use of lithium-ion batteries in energy storage systems. However, lithium iron phosphate (LFP) batteries release large volumes of flammable gases during thermal runaway, which are highly prone to ignition and can lead to fires or explosions. This necessitates a comprehensive investigation into the thermal runaway fire characteristics of LFP batteries. This study experimentally examines the fire hazards associated with thermal runaway in LFP batteries. Thermal runaway was initiated under different external heating power levels. Key parameters such as battery surface temperature, flame morphology, flame temperature, heat flux density, and heat release rate were analyzed to assess fire risk levels. Results demonstrate that thermal runaway flames exhibit two distinct stages: jet flame phase and stable combustion phase, with a maximum flame area of 0.44 m². Hazard parameters increased rapidly over time, reaching a fire hazard index (FED) of 100 within 72 s after flame emergence. The peak heat release rate reached 304.4 kW, and the total heat release was measured (20.51±1.04) MJ. Thermal runaway flames exhibited a noticeable lifting phenomenon, with fire hazards primarily arising from intense thermal radiation and substantial heat release due to the combustion of electrolytes and flammable gases. This study provides a comprehensive analysis of thermal runaway fire behaviors in 280 Ah LFP battery, offering theoretical support and practical guidance for fire prevention, suppression, and emergency response planning in energy storage facilities.

To address fire hazards posed by thermal runaway gases in large-capacity lithium iron phosphate (LFP) batteries, this study combines experiments and numerical simulations to investigate combustion characteristics and reaction pathways. A combustion‐rate tester was used to measure flame propagation speed and observe flame morphology, while Chemkin-Pro simulations quantified radical concentrations and the sensitivity of elementary reactions. The flame morphology depends on the equivalence ratio and is more stable under fuel-rich conditions. Flame propagation speed shows a unimodal dependence on equivalence ratio, peaking at approximately 56.4 cm/s at ϕ = 1.1, where heat release and radical concentrations are highest and flame propagation is most stable. Variations in temperature and pressure alter radical distributions and reaction-step sensitivities, thereby affecting flame propagation speed: the speed increases with temperature and decreases with pressure. These results provide a theoretical basis for prevention, monitoring, and emergency response to thermal-runaway gas fires in energy-storage stations and inform the optimization of safety design and fire-suppression strategies for such installations.

The thermal-runaway characteristics and mechanisms of large-capacity sodium-ion batteries (SIBs) are systematically investigated under different abuse conditions. Using commercial prismatic SIBs with a nominal capacity of 185 Ah as research objects, thermal runaway was induced by two methods: heating plate and continuous charging, while monitoring the temperature distribution, voltage changes, and expansion-force evolution. The experimental results reveal significant differences in the thermal-runaway processes and characteristics under different abuse conditions: (1) Heating-induced thermal runaway is characterized by localized overheating as the trigger, with heat diffusing from the outside to the inside, resulting in a non-uniform temperature distribution. The battery safety valve opens prematurely at 268.61 ℃, with a maximum expansion force of 1213 kPa. This process is relatively gradual, lasting approximately 820 s; (2) Overcharge-induced thermal runaway exhibits accumulative electrochemical instability, with the voltage increasing from 3.85 V to a peak of 4.89 V before plummeting. The expansion force gradually increases to 2402 kPa before the safety valve opens, resulting in more intense thermal runaway, accompanied by open flames, with the entire process lasting approximately 6996 s, which is 8.5 times longer than the duration of heating-induced thermal runaway; (3) Regarding the temperature characteristics, heating-induced thermal runaway can exceed 600 ℃ with uneven distribution, while overcharge-induced thermal runaway reaches peak temperatures exceeding 500 ℃, accompanied by more abrupt changes; (4) regarding the post-runaway physical states of the SIBs, the battery safety valve remains relatively intact under heating conditions, although with cracks appearing on the heated surface. However, the safety-valve area is severely damaged under overcharging conditions; (5) A comparison of the thermal-runaway initiation times reveals that the batteries subjected to heating begin to enter the thermal-runaway phase in just 597 s, whereas those subjected to overcharging require 3400 s of accumulation to trigger thermal runaway, indicating fundamental differences in the initiation mechanisms under different abuse conditions. These findings elucidate the triggering mechanisms and evolution processes of thermal runaway in SIBs and provide significant insights into understanding the safety characteristics of large-capacity SIBs, optimizing battery-management systems, and formulating early warning strategies for thermal runaway.

Titanium-based hydrogen storage alloys have emerged as a prominent focus of research due to their high volumetric hydrogen storage density at room temperature, fast absorption/desorption kinetics, low operating pressures, abundant availability, and excellent reversibility. However, studies exploring the control of hydrogen absorption and desorption rates within titanium-based metal hydride reactors remain limited. To address this gap, this study presents the design and simulation of a titanium-based metal hydride hydrogen storage reactor optimized for assembly efficiency, refillability, and enhanced thermal management. Hydrogen absorption and desorption kinetic parameters of TiFe_0.8Mn_0.2 were extracted from pressure-composition-temperature (P-C-T) curves, and a three-dimensional, coupled multiphysics model integrating fluid flow, heat transfer, and reaction kinetics was developed to simulate the system's behavior under varying thermal conditions. The model was used to evaluate the influence of key design and operational variables—including hydrogen inlet and outlet pressure, spacer distance, heat transfer fluid temperature, and flow rate-on reactor performance. The results show that under the conditions of hydrogen inlet pressure of 3 MPa, initial porosity of 0.4, baffle spacing of d, and dimensionless cooling fluid temperature of 0.083, the volumetric hydrogen storage density of the reactor after saturated hydrogen absorption can reach 55.4 g/L. At a dimensionless time of 0.219, the reaction fraction of metal hydride reaches 0.95, demonstrating high energy density and fast reaction rate. Under the conditions of hydrogen outlet pressure of 0.3 MPa, baffle spacing of d, and dimensionless heating fluid temperature of 1, the hydrogen release amount at the end of the reaction reaches 88.6% of the saturated hydrogen absorption amount. At a dimensionless time of 1, the hydrogen release amount is 84.8% of the saturated hydrogen absorption amount, providing important guidance for the design of large-scale hydrogen storage devices.

Battery modules exhibit a complex status in energy storage systems, and the accurate identification of abnormal lithium-ion batteries is crucial for system safety and stability. To resolve the shortcomings of traditional anomaly detection methods, such as their insufficient real-time performance and strong dependence on abnormal samples, an unsupervised anomaly detection method that integrates the local outlier factor (LOF) algorithm with spatiotemporal features of battery-operation data is proposed. This method comprehensively explores inter-cell consistency and data variation to achieve efficient, real-time, accurate abnormal celldetection without the need for pre-training. Specifically, the method involves: designing a Cornish-Fisher expansion-based distribution correction approach to calculate thresholds; utilizing a sliding-window mechanism to segment the continuous data stream from energy storage stations into dynamic data slices, thereby improving responsiveness to sudden anomalies; and applying the LOF algorithm for the local-density analysis of time series data within each window to detect low-density outliers and enable unsupervised anomaly detection. Experimental results on the dataset from 3920 to 3960 reveal that the proposed method accurately detects abnormal cells No. 155 and No. 364. These results are fully consistent with manual labeling, with zero false positives or negatives. Furthermore, the proposed method achieves the shortest average detection time of 0.0106 seconds, outperforming traditional methods, such as K-means clustering, isolation forest, Shannon entropy, and autoencoders, thus underscoring its excellent generalizability and engineering adaptability.

Replacing traditional liquid electrolytes with solid-state electrolytes is a critical strategy for enhancing the intrinsic safety of lithium-ion batteries. To evaluate the impact of electrolyte solidification on heat and gas generation during thermal runaway, this study compares commercially available semi-solid electrolyte lithium iron phosphate batteries (LFP-SS) with liquid electrolyte lithium iron phosphate batteries (LFP-L) and liquid electrolyte ternary battery (NCM523). The results show that the thermal runaway initiation temperature of LFP-SS does not exceed 220 ℃, while its peak temperature exceeds 470 ℃, suggesting slightly lower thermal safety than LFP-L. The unit capacity gas production of LFP-SS after thermal runaway is 0.541 L/Ah, which is higher than that of LFP-L. However, both batteries produce mixed gases with similar compositions, although the explosion limit range of LFP-SS is narrower. Compared with the 45 Ah semisolid electrolyte LFP soft pack battery, the large-capacity LFP-SS cell exhibits intensified thermal hazards but reduced explosion risk. The NCM523 battery demonstrates significantly lower thermal stability and safety than both LFP types, with gas production per unit capacity 3.4—4.2 times higher. However, its hydrogen content is approximately half that of the LFP batteries, and its explosion limit range is also narrower.

Energy storage is an important part of the new power system and plays an important role in achieving carbon peak and carbon neutrality. Lithium-ion may cause the power station to burn or explode when they encounter extreme abuse under the influence of internal and external triggers such as electricity, heat, and mechanics. For a long time, research on safety early warning technology for lithium-ion battery energy storage based on battery temperature, gas, internal resistance, and voltage characteristics has been widely concerned. This paper constructs a multiparameter test platform for overcharge thermal runaway of batteries and studies the voltage, temperature, and deformation change characteristics of prismatic lithium iron phosphate battery cells during the process ofcharge thermal runaway. The results show that the large surface of the prismatic lithium iron phosphate battery cell detects deformation earlier than the side surface because of the use of fixtures in experiment, and the final deformation amount of the large surface is less than that of the side surface. The upper surface sensor of the prismatic lithium iron phosphate battery cell can change. The deformation monitoring of the prismatic lithium iron phosphate battery cell is 100 seconds ahead of the temperature monitoring, which plays a certain role in preventing the occurrence of and the expansion of fault scale in energy storage power stations, and also reserves more time for the fault handling of energy storage batteries. This method provides a new direction for the safety early of lithium-ion batteries for energy storage and further technical support for the later application of energy storage projects.

State of charge (SOC) is a crucial parameter for characterizing the remaining capacities of electric vehicles (EVs). Accurate SOC estimation ensures EV safety and reliability. To facilitate accurate estimation of battery SOC in complex environments, the equivalent circuit model is constructed based on the characteristics of power batteries, and the equation of state (EOS) of the battery model is discretized. Further, to obtain the discretized EOS, the golden-jackal-optimization algorithm is combined with the forgetting factor recursive least square (FFRLS) algorithm to yield an improved FFRLS method for identifying the parameters of the battery model. Concurrently, the interacting multiple-model unscented Kalman filter (IMMUKF) algorithm is used to estimate the battery SOC, which is experimentally verified via dynamic stress tests (DST) and federal urban driving schedules (FUDS) at room and high temperatures. The experimental results indicate that the mean absolute error of the proposed improved IFFRLS-IMMUKF-based lithium-battery SOC-estimation method is within 0.8% and that the SOC-estimation accuracy for lithium iron phosphate batteries is high.

To address the instability of the internal solid-solid interfaces in all-solid-state lithium metal batteries caused by the expansion behavior, which leads to poor cyclability, this study examines the effect of the stack pressure on the electrode and solid electrolyte (SE) contact. A two-dimensional axisymmetric force–electric coupling homogeneous battery model was developed using NCM811, Li₆PS₅Cl, and lithium metal as the cathode, SE, and anode, respectively. The model was constrained to its initial state during the charge-discharge cycles to analyze the factors influencing the internal expansion forces. The results show that lowering the cathode's Young's modulus effectively mitigates the fluctuation in the expansion force. Specifically, a cathode with a Young's modulus of 300 MPa reduced the maximum expansion force to 2.89 MPa, with a peak stress of 12.5 MPa. Adjusting the lithium metal anode thickness (20—200 µm) helps alleviate the volume strain at the SE-anode interface by enabling the deformation of the lithium metal, thereby reducing the anode volume strain and charging-induced swelling stress. These findings highlight the key factors affecting the internal expansion forces and provide design strategies for improving the next-generation ASSLMB performance.

This study presents a flame-combustion-driven one-step in situ modification strategy to construct a porous NiFe composite oxide catalytic layer (NiFe/316L) on 316L stainless steel, achieving synergistic optimization of oxygen evolution reaction (OER) activity and industrial-grade stability. A hierarchical porous structure with interconnected channels was fabricated through high-temperature flame oxidation coupled with rapid quenching, inducing alloy phase separation and multiscale pore formation. X-ray photoelectron spectroscopy confirmed the coexistence and uniform distribution of Ni, Fe, and O species across the electrode surface. In 1 mol/L KOH electrolyte, the optimized electrode exhibited excellent OER performance with a low overpotential of 256 mV at 10 mA/cm², a Tafel slope of 40.8 mV/dec, and a sevenfold increase in electrochemically active surface area (141 cm²) relative to the bare substrate. The charge transfer resistance decreased markedly from 202.9 Ω to 3.36 Ω. Under industrially relevant conditions (30% KOH, 80 ℃), the electrode demonstrated outstanding durability with negligible performance decay after 100 h of continuous operation at 1000 mA/cm², surpassing most reported non-precious metal catalysts. This work offers a cost-effective and scalable approach for fabricating industrially viable OER electrodes

Phase change thermal energy storage (PCTES) systems utilize the latent heat absorbed or released during material phase transitions to store and discharge thermal energy. These systems offer key advantages such as high energy density, stable temperature operation, and compact volume. This study integrates topology optimization into the design of shell-and-tube PCTES units to accelerate the melting process and improve overall thermal performance. A mathematical optimization model is developed using dimensionless governing equations to investigate the effects of thermal diffusivity ratio, Stefan number, and natural convection on the evolution of fin geometries. Topology-optimized structures are reconstructed geometrically, followed by numerical simulations and performance comparisons with conventional straight-fin structures and non-reconstructed optimized designs. The key findings are as follows: (1) Natural convection exerts a significant influence on the topology-optimized structure, resulting in notable differences between conduction-dominated and convection-enhanced designs. (2) A lower thermal diffusivity ratio or a higher Stefan number promotes radial expansion of the fin structures, enhancing heat transfer pathways. (3) Among five evaluated configurations, topology-optimized designs demonstrate substantial improvements in thermal charging efficiency. Specifically, the convection-enhanced design reduces the time required to reach an average dimensionless temperature of 0.9 by 30.1%, and shortens the total phase transition duration by 50.8%. The results also indicate that conduction- and convection-optimized designs offer distinct advantages depending on the application context and storage objectives, underscoring the importance of scenario-specific optimization. This work provides a novel approach and practical insights for the efficient design of phase change thermal energy storage systems across various thermal management applications.

Supercapacitors are modern physical energy storage devices with advantages such as high power and long lifespan. However, during its charging and discharging process, excessive heat may be generated due to internal resistance issues, leading to a significant increase in its own temperature and affecting its lifespan and performance. This article discusses in detail the working mechanism of supercapacitors, including their structural characteristics, application features, and heat generation mechanism. Through thermal energy analysis, the temperature distribution, heating rate, and thermal stress of supercapacitors during charging and discharging processes were evaluated. Furthermore, this article introduces the method of using MATLAB or Simulink environment for virtual simulation analysis, including establishing equivalent circuit models, parameter settings, and simulation result analysis. The simulation results indicate that the temperature of supercapacitors changes significantly during charge and discharge cycles, and effective thermal management measures need to be taken to control the temperature. This study provides a new perspective and method for thermal energy management and performance optimization of supercapacitors.

This paper deeply explores the energy recovery and control strategy of rail tram based on energy storage technology. By analyzing the operation characteristics and energy consumption of rail tram, the principle and technical means of energy recovery are expounded, and the characteristics of different energy storage devices and their applications in rail tram are discussed in detail. At the same time, a complete framework of energy recovery and control strategy is proposed, including energy management strategy, charge and discharge control strategy, as well as system coordination and optimization, etc. The purpose is to improve the energy efficiency of rail tram, reduce operating costs and achieve sustainable development.

Analyzing patent information pertaining to lithium-ion battery technologies used in electric vehicles in both China and the United States is conducive to identifying international mainstream innovation-driven trends in developments for this technology and China's position in this international competition. This analysis can also serve as a valuable reference for attaining high-quality development and high-level security of relevant technologies and industries within China. By analyzing information obtained from the incoPat patent database, we conducted a comprehensive comparison of innovations in automotive lithium-ion battery technologies between the two countries from three perspectives: patent quantity, patent quality, and technical fields and hotspots. We find China has made a notable effort to catch up with the U.S. in terms of patent quantity; however, its performance based on patent quality is less remarkable. In terms of the command of basic core technologies and the market value of patent outcomes, China still faces certain shortfalls compared with the U.S. Both countries hold advantages at specific stages of the technology life cycle. Whether China can achieve breakthroughs in key technologies in the short-to medium term will determine the future competitive landscape between the two nations. While both countries have dedicated significant R&D resources to key core technologies in automotive lithium-ion batteries, their technical research priorities and the technological goals they emphasize vary. Based on our analysis, we offer recommendations for future development efforts in China from three perspectives.

With the rapid expansion of the scale of talent cultivation in the energy storage field, the role of postgraduate education has become increasingly important. In this case, the optimization of the training mode of high-level talent in energy storage is urgently needed. An analysis of the current state of graduate education in energy storage shows that, while establishing dedicated energy storage platforms or research institutes facilitates the integration of interdisciplinary faculty and laboratory resources, such initiatives face significant challenges in terms of funding and faculty allocation. As a result, most universities continue to rely on their existing energy-related schools to train graduate students in energy storage. The key challenges of training graduate students in energy storage are as follows: limited research directions of supervisors and a shortage of interdisciplinary research projects, a lack of diverse course offerings and insufficient interdisciplinary practical courses, an imperfect evaluation system and inadequate internationalization, poor experimental conditions for cross-disciplinary work, and weak mechanisms for resource sharing between disciplines. Given the distinct interdisciplinary characteristics of postgraduate talent cultivation in energy storage, Hebei University of Technology has developed and implemented an interdisciplinary training mode for graduate students in energy storage based on the status of talent cultivation in other Chinese universities and research institutes, as well as the demands of the energy storage industry. This mode primarily includes the following measures: integrating faculty from multiple disciplines and industry experts to form a cross-disciplinary mentoring team, along with implementation of a multi-mentor collaborative guidance mechanism; optimizing teaching teams for Energy Storage Technology and Thermal Energy Storage Technology and Applications, incorporating interdisciplinary knowledge and cutting-edge advancements into curricula, and compiling a new text book; establishing an academic research system featuring distinguished scholar lectures, graduate academic forums, interdisciplinary research collaborations, and a multi-phased engineering practice mechanism; building a cross-disciplinary platform that integrates experimental equipment and simulation tools from power engineering and engineering thermophysics, materials science and engineering, chemical engineering and technology, mechanical engineering, and electrical engineering. These efforts have enhanced the interdisciplinary innovation capabilities, engineering practical skills, communication and collaboration abilities, and awareness of the cutting-edge of graduate students in the energy storage field. This approach provides a valuable reference for other universities and research institutions in cultivating talent in this field.