Lithium-ion batteries play a pivotal role in achieving carbon neutrality goals through their widespread applications in electric vehicles, portable electronics, and energy storage systems. However, lithium plating—a critical process that occurs at the anode during charging—poses a significant challenge, compromising both safety and performance. This study systematically investigates the formation mechanisms and influencing factors of lithium plating, revealing that the synergistic effects of battery design flaws and extreme operating conditions (such as a low-temperature environment, fast charging, and overcharging) can drive the anode potential below 0 V vs.\mathrm{L}\mathrm{i}/\mathrm{L}{\mathrm{i}}^{+}, triggering the deposition of metallic lithium. The irreversibility of lithium deposition leads to three critical consequences: continuous thickening of the solid electrolyte interphase (SEI) layer, accumulation of “dead lithium”, and dendritic lithium growth. These effects collectively contribute to capacity degradation and thermal runaway risks.To address the challenges in detecting lithium deposition, this study provides a comprehensive classification and critical review of existing technologies from the perspective of in situ detection. Quantitative detection methodologies include electrochemical characterization techniques (e.g., differential voltage analysis, differential voltage relaxation analysis, incremental and capacity analysis and physical characterization approaches (e.g., nuclear magnetic resonance spectroscopy and X-ray technology). Qualitative detection strategies involve electrochemical impedance spectroscopy (EIS) and thickness or pressure monitoring systems. Compared to postmortem analysis requiring battery disassembly, these advanced methods offer novel insights for real-time monitoring applications.This study establishes an innovative dual-dimensional safety assessment framework encompassing thermal safety and performance safety, with the former focusing on heat generation characteristics and thermal stability thresholds during lithium plating and the latter on quantifying capacity fade rates and impedance growth patterns. This systematic approach provides a theoretical foundation for developing high-safety, long-cycle-life batteries.Finally, to address the shortcomings in current in situ lithium plating detection, the following recommendations are made: ① establishing a systematic definition of battery safety standards and correlating lithium plating detection with thermal and performance safety; ② combining electrochemical detection with big data to extract and fuse useful features for online safety diagnosis; ③ developing innovative in situ quantitative methods for visual monitoring and quantifying complex internal reactions, and ④ providing scientific guidance to overcome the bottlenecks in in situ lithium plating detection technology.

solid oxide fuel cells (SOFC) are highly efficient, all-solid-state electrochemical energy-conversion devices that can directly transform the chemical energy of fuel into electricity. SOFCs are one of the most advanced green fuel cell technologies owing to their unique advantages, such as environmental friendliness, high power-generating efficiency, and wide fuel adaptability. The stable operation of SOFCs depends on their structural design and assembly, with the structure serving as the core structure that determines the mechanical strength, assembly process, and electrochemical performance. This study reviewed recent related literature on SOFC support structures, categorizing them into three main types: electrolyte, electrode (anode and cathode), and metal supports. The material composition, function characteristics as well as preparation methods of the three supports were examined. The research status of the three supports is summarized below. In addition, the important factors affecting the selection of support materials and battery performance were analyzed from different perspectives. Along with the existing research reports, this study proposes optimization strategies to improve existing support structures. The major challenges and complexity in the functional section of SOFC support include: (i) improving the mechanical strength while reducing the thickness of the electrolyte support, (ii) maintaining the structure stability and inhibiting carbon deposition of the anode support, (iii) reducing the concentration polarization of the cathode support, (iv) improving the oxidation resistance and adaptability of the metal support. Furthermore, developing novel SOFC materials that match the structure of each support is the focus of current and future research, as well as the realization of SOFCs with low temperature, low cost, and long-term durability. This article provides a comprehensive review with respect to the material, property, preparation, underlying mechanisms, and performance of SOFC support, and provides future directions for SOFC development.

With the advancement of the new power system construction, the importance of independent energy storage has become increasingly prominent. However, the imperfect mechanism for its participation in the electricity market in China has affected investment enthusiasm. By comparing international experiences, providing a path reference for the market-oriented development of independent energy storage in China can help promote the healthy and sustainable development of independent energy storage. This paper first introduces the market mechanisms for independent energy storage in the United States, the United Kingdom, and Australia in participating in spot markets, ancillary service markets, and capacity markets. It summarizes the experience of mature foreign markets in fully unleashing the value of energy storage through multi-dimensional market mechanism design, higher price caps in spot markets, and stable capacity market revenues. Secondly, the development status of China's independent energy storage in participating in the spot market, auxiliary service market, capacity market, etc. was summarized, and the shortcomings of the domestic spot market in terms of low price ceiling, single auxiliary service variety, and undeveloped capacity compensation mechanism were analyzed. Finally, by comparing the differences in the participation of independent energy storage in electricity markets between China and foreign countries, this paper draws insights for China's trading mechanisms for independent energy storage in electricity markets, and proposes that China should improve and optimize in terms of enriching the market types for independent energy storage participation, optimizing the price mechanism of spot markets, reasonably channeling the costs of independent energy storage, and strengthening market supervision and risk prevention.

Against the backdrop of China's carbon peaking and carbon neutrality goals, new energy storage has become a key infrastructure and technology that supports the building of a new power system. It has gradually emerged as a strategic and competitive industry worldwide. While China's new energy storage industry leads in technology and market, the industry is undergoing a critical transition from the research and demonstration phase to large-scale deployment. In this regard, several key developmental challenges remain. These challenges require collective efforts and solutions. This study first reviewed the development status of the new energy storage industry, focusing on the characteristics and progress of the industry from policy, market, and technology viewpoints. It then analyzed the key challenges to the high-quality development of the industry, highlighting that low-quality, low-price competition has become the main limitation. Additionally, deficiencies in safety standards, market mechanisms, data sharing, and overseas compliance are areas that require further improvement. In light of these challenges, several policy recommendations and solutions are proposed considering the following five aspects: (1) safety and performance rating and evaluation mechanism, (2) grid-connection testing and verification and annual mandatory safety inspection, (3) capacity compensation mechanism and insurance product tailored to energy storage, (4) data management and industry-wide sharing, and (5) mutual recognition globally of green certificates and pilot projects of direct green power supply. These recommendations aim to provide some insights into the high-quality development of the industry.

New-type energy storage approaches, as a crucial component and key pillar in the construction of China's new energy system, play a vital role in ensuring the secure and stable operation of the modern power system and driving the transition to green and low-carbon technologies. While China has recently witnessed rapid growth in new-type energy storage installations and the gradual development of a policy framework, the industry still faces multiple challenges in achieving high-quality development. This study systematically reviews the evolution of the new-type energy storage industry in China, summarizes the key policies introduced since the 14th Five-Year Plan period, and thoroughly analyzes the progress and critical issues in technological innovation, technoeconomic viability, industrial competition, and institutional mechanisms. The findings revealed that China is currently at a critical juncture in integrating the new-type energy storage with the power system, with significant future potential. However, challenges such as high costs, pending breakthroughs in disruptive technologies, immature electricity market and dispatch mechanisms, intensifying "involution" and growing obstacles in global expansion persist. To address these issues, it is imperative to advance coordinated planning across power generation, grid infrastructure, load management, and storage systems; improve top-level institutional design and legal safeguards; accelerate breakthroughs in key technological bottlenecks; expedite product upgrades and iterations; refine electricity market and pricing mechanisms; enhance profitability; and promote broader and more diversified applications of new-type energy storage. These efforts will facilitate the transformation of the energy system and industrial upgrading.

Phase change materials (PCMs) can alleviate energy concerns to some extent via reversible storage of thermal energy. PCM-based heat accumulation technology holds significant potential for temperature regulation and thermal storage applications. However, their wider development and application are limited by deficiencies such as low thermal conductivity, leakage during the solid-liquid phase change process, and a single function. Interestingly, organic, porous, and shape-stabilized materials, primarily biomass-based and polymer-based porous materials, have been recognized as support materials for constructing shape-stabilized composite PCMs. Multi-function PCMs with stable shapes can be prepared by encapsulating PCMs with organic, porous, and shape-stabilized materials combined with other functional materials, effectively addressing the aforementioned problems in the field of phase-change heat storage. This paper describes four preparation methods—physical blending, vacuum impregnation, chemical grafting, and electrospinning of biomass-based and polymer-based multi-porous composite phase-change thermal storage materials and compares their advantages and limitations. Thereafter, the latest advances in the preparation of organic, porous, and shape-stabilized composite PCMs through direct and functional compositing methods are reviewed to understand the inherent limitations of traditional PCMs. The thermal properties of these composite materials are systematically summarized. Additionally, the typical applications of these PCMs in the fields of solar energy storage, industrial waste heat, intelligent buildings, wearable fabrics, electronic devices, and biomedicine are described. Furthermore, the current challenges are highlighted to inspire more research ideas for developing in detail novel and excellent properties of composite PCMs.

GB/T 31486—2015 "Electrical performance requirements and test methods for traction battery of electric vehicle" is a critical standard in the field of traction battery electrical performance. The new energy vehicle and traction battery industries have seen rapid development in recent years, leading to a shift toward "cell to pack" (CTP), and a deeper understanding of real-world operating conditions. In addition, advancements in battery performance have surpassed the levels established in the 2015 version. Consequently, China published the revised GB/T 31486—2024 in 2024. The updated standard, implemented on April 1, 2025, is a core document in the traction battery sector and is important for product development and validation. This study analyzes the background and key technical updates of the GB/T 31486—2024 standard, highlighting its differences from the 2015 version. The revisions focus on three main aspects: (i) Alignment with "CTP" technology: test objects are shifted from modules to cells, with increased sample sizes to enhance consistency evaluation. (ii) Optimized test conditions: test parameters are optimized based on real-world operational data, and dynamic environmental adaptation termination mechanisms are integrated. (iii) Elevated performance requirements: The overall performance criteria are increased. Furthermore, GB/T 31486—2024 emphasizes coordination with domestic standards, such as GB/T 31467—2023, ensuring that test results more accurately reflect actual operating conditions. By upgrading technical specifications and innovating testing methodologies, the revised standards can drive enterprises toward improving product performance and consistency control, thereby providing vital support for the high-quality development of China's new energy vehicle industry.

Lithium-ion battery modules (LIBMs) are currently the most widely used battery components in energy storage systems. Thermal runaway events can significantly compromise the reliable operation of an energy storage system. Existing models for the qualitative analysis of thermal diffusion cannot be directly used to evaluate the thermal diffusion probability of LIBMs quantitatively under time-varying operation conditions. To overcome this problem, a fuzzy reasoning-based method for evaluating the thermal diffusion probability of LIBMs is proposed in this work. The study first built a thermal diffusion simulation model of LIBMs on the COMSOL platform. This model was used to analyze the effects of various heating modes, LIBM arrangement configurations, and state of charge (SOC) on LIBMs and to investigate the mechanisms of thermal diffusion in LIBMs. Subsequently, a fuzzy reasoning system was constructed based on the simulation test data. The cell temperature, inter-cell distance, and ambient temperature of the lithium-ion battery were taken as inputs, and the LIBM thermal runaway probability was the output. To improve the accuracy of the evaluation results, the improved dung beetle optimizer (IDBO) was used to optimize the membership function parameters in the fuzzy reasoning system. The results revealed that reducing the contact area between cells in an LIBM effectively mitigated thermal diffusion; additionally, slow heating of the LIBM resulted in a higher thermal runaway temperature for the last cell in the module to experience thermal runaway. The Pearson correlation coefficient of the thermal diffusion probability evaluation results obtained by the proposed method was higher compared with that of the traditional dung beetle algorithm, particle swarm algorithm, and sparrow search algorithm by 0.076, 0.041, and 0.047 respectively. The high coefficient provides a more reasonable reference basis for the risk warning of LIBM thermal diffusion in energy storage systems in engineering practice.

Fully combine the technical and economic characteristics of lithium batteries, such as high energy density, long discharge time, short cycle life, low economic cost, and poor safety, with the technical and economic characteristics of supercapacitors, including high power density, short discharge time, long cycle life, high economic cost, and good safety. Complement each other's advantages to form a hybrid energy storage system consisting of lithium batteries and supercapacitors, and configure a grid-forming converter to establish a hybrid grid-forming energy storage system with lithium batteries and supercapacitors. Based on the application scenarios of grid-forming energy storage, the grid-forming control scheme is clarified, and a hybrid energy storage power distribution scheme is explored, where lithium batteries are responsible for the power regulation requirements of low frequency and large capacity, and supercapacitors share the power regulation requirements of high frequency and small power. Moreover, simulation analysis and tests are carried out based on the simulation model of the grid-forming energy storage with new energy system in Matlab/Simulink and the first national hybrid grid-forming energy storage demonstration project. The results show that the "heterogeneous voltage sources" based on two different energy storage entities can be used in parallel, and the technical advantages of the two energy storage entities can be fully utilized to make up for the deficiencies of a single energy storage form. And the service life of the system can be extended based on the hybrid energy storage power distribution scheme. Improve the technical and economic performance of grid-forming energy storage stations throughout their entire life cycle. This research helps to promote the popularization and application of the hybrid grid-forming energy storage system with "lithium batteries + supercapacitors" in new energy stations and regions with weak grids, provides support for the power grid, increases the grid-connected power generation of new energy, and promotes the construction of a new power system and energy transformation.

Heating systems based on the clean energy heat pump achieve energy conversion through electrical power. The economic efficiency of the system can be drastically improved by leveraging time-of-use electricity pricing policies and utilizing the heating pipe network as a thermal storage medium for peak-valley load shifting. Addressing the conflict arising from peak-valley electricity pricing for clean energy heating systems in northern regions, this study proposes an energy storage solution based on existing heating pipe networks to construct a "source-storage-load" coordinated direct pipe network storage system.Taking the Qingdao High-tech Zone project (a heating area of 227,400 m² and a pipe network water capacity of 2000 tons) as an engineering case study, a multi-source parallel architecture was adopted. Three key technologies were implemented: ① integrating the primary pipe network and heat exchangers into distributed thermal storage units, ② developing a "quality-quantity dual regulation" control algorithm, and ③ establishing a SCADA real-time monitoring and cloud-based control platform.Operational data indicate that the system can achieve a rise of 8.25 ℃ in the primary network temperature during off-peak electricity periods. Although measured data indicate that R134a units can reach temperatures of up to 75 ℃, long-term operation under these conditions is not recommended. This rise allows for a complete shutdown for 10 h during the peak and flat electricity-price periods, while maintaining secondary network temperature fluctuations within 0.8 ℃.An economic assessment revealed that through the time-of-use pricing strategy (peak price: 1.25 RMB/kWh; deep valley price: 0.28 RMB/kWh), the project could achieve an annual revenue of 1.161 million RMB, with a dynamic payback period of 1.75 years. The study also confirmed that in this project, the investment cost per unit building area is only 8.3 RMB.This technology provides a flexible control solution for regional integrated energy systems. This solution is both economical and reliable, holding significant value for achieving the "dual carbon" goals.

Lithium plating is one of the main contributors to internal short-circuit failures in energy storage lithium-ion batteries. The online monitoring of the lithium plating process is a key direction in research for ensuring battery safety. However, existing methods are limited to monitoring reversible lithium plating in engineering applications, and machine learning-based online monitoring algorithms have difficulty with model training due to the lack of lithium plating data from actual batteries. To address these problems, this work proposes a method for monitoring irreversible lithium plating using unsupervised domain adaptive transfer learning. The source and target domain data for the irreversible lithium plating monitoring model were generated through simulations using an electrochemical-thermal-aging model and low-temperature lithium plating aging experiments. Features related to lithium plating were extracted from the discharge curves, and an irreversible lithium plating monitoring model based on a multilayer perceptron was developed within an unsupervised unsupervised domain adaptive transfer learning framework. This allowed for the transfer of the irreversible lithium plating monitoring model from the source domain data to the target domain data. The results showed that on the simulated data, the algorithm achieved an accuracy rate above 99% in detecting the occurrence of irreversible lithium plating. On the experimental data, the qualitative judgements by the algorithm about the irreversible lithium plating were consistent with the actual conditions. This demonstrates that the proposed method can effectively monitor irreversible lithium plating in batteries and offers a new approach to the online monitoring of irreversible lithium plating in energy storage lithium-ion batteries.

The characterization of crystal morphology features is critical for revealing the solution–crystalline energy storage mechanism. The surface structure, pore distribution, and adsorption properties of crystals determine their adsorption and release efficiency during thermal energy storage. This study investigates the adsorption properties and microstructure features of both anhydrous and monohydrate lithium bromide (LiBr) crystals using advanced characterization techniques. This study provides detailed microscopic insights into the internal and external structures of LiBr crystals using a combination of vacuum vapor sorption analysis, scanning electron microscopy, and automatic surface area and pore size distribution measurements. The results demonstrate that under 90% relative humidity, anhydrous LiBr and monohydrate LiBr crystals exhibit adsorption of 3027.966 and 2322.909 mg/g, respectively. The LiBr crystals exhibit a rough surface microstructure characterized by etching craters, which serve as active dissolution sites and significantly affect the adsorption and desorption processes of the crystals. Under dry conditions (absence of liquid film), the specific surface areas of the micropores of anhydrous and monohydrate LiBr crystals are 1.1×10^-2 m²/g and 8×10^-3 m²/g, respectively, and the specific surface areas of the mesopores are 7.7×10^-2 m²/g and 8×10^-2 m²/g, respectively. During water vapor absorption, LiBr crystals initially adsorb water vapor through surface pores. Once the adsorption reaches saturation, the crystals continue to absorb water vapor via dissolution. By adjusting the hydration state of LiBr crystals, their energy storage performance can be optimized while improving system stability. These findings provide both experimental and theoretical support for the optimization of solar thermal energy storage technology and the selection and design of materials for efficient thermal storage systems.

The Carnot battery is a thermomechanical energy storage technology based on the Carnot cycle. It stores electrical energy in the form of thermal energy. Some of its advantages are its simple structure, environmental friendliness, high economic efficiency, and strong flexibility. This study explored the design of 10 MW high-temperature CO₂ Carnot battery systems based on the Brayton cycle and the supercritical Rankine cycle. Mathematical models of the system and its components were established. The impact of various sensible heat storage methods on the thermodynamic performance of the system was examined, and a thermoeconomic analysis was conducted. The study revealed that at a heat storage temperature of approximately 400 ℃, the CO₂ Carnot battery system based on the Brayton cycle achieves a round-trip efficiency of 66.6%, whereas the system based on the supercritical Rankine cycle achieves a round-trip efficiency of 60.4%. The influence of parameters such as working fluid flow rate and inlet pressures of the high-temperature compressor and high-temperature expander on system performance was analyzed. Thermodynamic and economic analyses were conducted for different cycle processes and components, and recommendations were made to optimize the system. The comprehensive evaluation of thermodynamic performance and economic feasibility identified the supercritical Rankine cycle CO₂ Carnot battery with solid heat storage as the optimal choice. The findings of this work offer valuable insights for the design optimization and application of CO₂ Carnot battery systems.

The coupling of molten salt heat storage and coal-fired power unit can effectively regulate unit output and improve unit flexibility. In this article, based on a 600 MW coal-fired unit as the research object, 3 operation schemes for peak shaving aided by molten salt heat storage are constructed, including heat storage from extracted main steam and heat release to bypass feedwater, deaerated water and condensate water. The economic performance of 3 schemes is compared and analyzed by studying the effects of factors such as return water parameters of extracted main steam, heat storage/release power, and heat storage/release duration on economic indicators such as payback period and levelized cost of energy (LCOE). The results indicate that as the return water temperature increases, the payback period of the 3 schemes gradually shortens, while the LCOE slightly rises. The scheme of bypass feedwater has the best economic performance. When the return water temperature is 309.4 ℃, the heat storage/release power is 25 MW, and the heat storage/release duration is 1 hour, the payback period is 5.521 years, and the LCOE is 0.4485 yuan/kWh. With the increase of storage/release power and duration, the payback period and LCOE of this scheme have both increased.

To address the frequency fluctuation problem in isolated network systems during power restoration, a frequency control method was proposed. The proposed method leverages distributed energy storage to provide power support. First, a time-domain model of an isolated grid system during power restoration was established using the frequency response characteristics of distributed photovoltaic and energy storage devices. Second, a frequency control strategy for energy storage support was constructed, and stable margin optimization and transient frequency optimization control modes based on model predictive control were developed. The weight coefficient between the objective functions was obtained using the Harris Hawk optimization algorithm. Finally, the frequency modulation performances under different control strategies were compared through simulation examples to verify the effectiveness of the proposed method. The results demonstrate that the proposed method effectively improves the maximum frequency fluctuation and regulation time of the system, suppresses the frequency fluctuation problem in the power supply recovery process of the distribution network, and enhances the frequency control performance of the system.

Lithium-ion batteries are widely used in electrochemical energy storage and new energy vehicles. Thermal runaway-induced fires in these batteries pose significant threats to human life and property, restricting the development of electrochemical energy storage and new energy vehicle industries. Current research on lithium-ion battery thermal runaway mainly focuses on the phenomenon under single-abuse conditions. Studies on thermal runaway events triggered by multiple abuse are relatively scarce. Furthermore, the internal mechanisms of thermal runaway induced by electrothermal coupling are not yet well understood. This study investigated the thermal runaway characteristics of a 58 Ah ternary lithium-ion battery cell under the combined effects of electrical and thermal abuse. The differences in thermal runaway characteristics between electrothermal coupling and single abuse conditions were analyzed. Additionally, the effects of different overcharge levels and heating power on thermal runaway behavior under electrothermal coupling were examined. The results revealed that under electrothermal coupling abuse, thermal runaway progresses more rapidly, with an earlier onset of thermal runaway and valve opening, shorter venting and flame-ejection durations, a lower thermal runaway trigger temperature, and a higher peak thermal runaway temperature. These effects significantly raise the risk level. Batteries with a high state of charge (SOC) exhibit a greater risk of thermal runaway. The SOC boundaries for valve opening and thermal runaway for 100 W heating power under electrothermal coupling conditions were determined to be 120% SOC—125% SOC and 125% SOC—128% SOC, respectively. At 100 W and 200 W heating power, the battery voltage variation was similar to that under single overcharge conditions, while at heating powers exceeding 300 W, the variation resembled single overheating conditions. This result indicates that at low heating powers, the internal reaction mechanism under electrothermal coupling is closer to overcharging, whereas at high heating powers, thermal effects dominate. Under electrothermal coupling, thermal runaway progresses more rapidly at high heating powers, with an earlier valve opening and thermal runaway onset. However, at low heating powers, thermal runaway is more severe, exhibiting more intense ejection behavior and a higher peak thermal runaway temperature. Thus, this study provides valuable insights to enhance the safety performance of large-capacity ternary lithium-ion batteries under multiple abuse conditions.

Energy storage is a critical technology for the large-scale usage of renewable energy. Liquid carbon dioxide (CO₂) energy storage systems are recognized as promising large-scale long-duration energy storage technology owing to their high energy density, compact equipment, and enhanced safety. This study establishes a variable-operating-condition model of liquid CO₂ energy storage systems to elucidate the dynamic operational characteristics and the impacts of key parameters, including initial pressures of low- and high-pressure tanks, compressor efficiency, expander efficiency, and ambient temperature, on system performance under varying operating conditions. The analysis reveals the distribution of exergy destruction, cold storage units (36.53%), compressors (24.63%), and expanders (19.58%) are the primary sources of exergy destruction. Under typical operating conditions, the high-pressure tank of the system increased from 8 MPa to 14.5 MPa, with the corresponding temperature rise from 298.15 K to 307.32 K. In contrast, the low-pressure tank pressure decreased from 0.6 to 0.59 MPa, with the temperature decreased from 220 K to 219.85 K. In addition, the proposed system achieves a round-trip efficiency of 63.14%, which is 7.2% lower than the steady-state assumptions, with an energy density of 0.9237 kWh/m³—only 3.9% of the steady-state value, due to the exclusion of unused working fluid in steady-state models. These findings provide valuable insights for the optimization design and practical application of CO₂ energy storage systems.

As the penetration rate of electric vehicles (EVs) increases, their widespread integration significantly affects the power grid stability. To better absorb highly volatile renewable energy and manage uncertain EV charging demands, this study proposed a renewable energy system. The proposed system combines energy storage technology with wind power, photovoltaic power, and grid technology to create a renewable energy system. The disordered charging behavior of EVs was characterized using the Monte Carlo sampling method, and MATLAB was coupled with TRNSYS to build a dynamic system simulation model. An evaluation framework was proposed to comprehensively evaluate system performance across different time scales, technical forms, and control strategies. The analysis was based on three system control strategies. The results demonstrate that the system's annual energy matching index increased by up to 48.20%, its flexibility index decreased by up to 37.77%, and the environmental benefit index decreased by up to 6.59% after the introduction of energy storage technology. Through an orderly charging strategy, the system demonstrated strong performance metrics: an on-site energy fraction of 66.71%, on-site energy matching of 73.20%, grid integration level of 33.29%, and net interaction level of 52.63%. The proposed system effectively regulates loads, relieves pressure on the power grid, improves supply-demand mismatches due to EV loads, and decreases demand-side dependence on the power grid.

Irrigation is crucial for agricultural production. Traditional irrigation systems are commonly limited by high energy consumption and low efficiency. To address this challenge, this study introduces a distributed photovoltaic-storage (PV-storage) system as a clean energy solution for agricultural irrigation by focusing on exploring electricity consumption optimization strategies. An electricity consumption model was constructed by analyzing the seasonal characteristics of agricultural irrigation load in Heilongjiang region. This model encompasses multiple types of electrical equipment and intermittent load characteristics. A load transfer and interruption operation model was established by combining the intermittency and adjustable characteristics of the load during the irrigation cycle. Then, a system output model was built based on the power generation characteristics of the PV-storage system. Furthermore, for minimizing electricity costs within the park, an electricity consumption optimization model under time-of-use pricing was constructed. Simulation of summer irrigation scenarios validated the proposed strategy, showing that it reduced electricity costs by 41.2% compared to traditional methods. Thus, the economic benefits of PV-storage systems in the field of agricultural irrigation were demonstrated.

Lamellar nitrogen-doped reduced graphene oxide (rGO-P) was synthesized under controlled synthesis conditions. Subsequently, PANI/MnO₂ tubular pseudocapacitive materials were intercalated with rGO-P to form ternary PANI/MnO₂/rGO-P composites using a two-step hybridization method. X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy were used to analyze the microstructure and morphology of the composites. The electrochemical performance of the composites was evaluated through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements. The results demonstrate that PANI/MnO₂/rGO-P₇₅ exhibits a specific capacitance of 635 F/g at 0.5 A/g current density, with an energy density of 17.5 Wh/kg at a power density of 0.45 kW/kg, outperforming both rGO-P and PANI/MnO₂ binary composites at the same current densities. Furthermore, the material exhibits excellent cycling stability, retaining 82.0% of its specific capacitance after 5000 GCD cycles at 1 A/g. This study demonstrates that ternary composite electrodes significantly enhance supercapacitor performance compared to binary composite systems.

Renewable energy generation is transforming from a protected grid-connection model to a competitive electricity market model. However, because of their inherent uncertainty and intermittency, renewable sources struggle to independently and effectively compete in the electricity market. To address this issue, a wind-solar-battery-hydrogen hybrid power plant model based on renewable stations was developed to ensure a stable power supply, engage in electricity market transactions, and meet the hydrogen load demand. Within the electricity market environment, a two-level optimal configuration model was established for maximizing the return on equity (ROE), integrating medium- and long-term as well as spot market trading rules. The outer layer of the model employs the improved sparrow search algorithm to determine the optimal configuration strategy, utilizing the ROE as the fitness function. The inner layer applies mixed-integer linear programming to solve specific operational strategies. In addition, the model incorporates a quadratic constraint to model the hydrogen production curve of the electrolyzer accurately. This constraint is relaxed and transformed into a mixed-integer second-order cone programming problem, forming the optimal configuration scheme of the hybrid power plant. Case simulation results showed that the optimized configuration achieved an ROE of up to 0.32, which was further improved to 0.35 through enhanced operation based on hydrogen production efficiency. This configuration, therefore, enables the effective integration of electricity and hydrogen energy, significantly enhancing the competitiveness of renewable energy generation in the electricity market.

Molten salt energy storage is important for applications such as concentrated solar power generation and enhancing the flexibility of coal-fired power plants. However, various applications require these salts to operate at significantly higher temperatures. This study systematically investigates the high-temperature stability and decomposition products of two typical nitrate salts, Solar Salt and Hitec under air conditions. The salts were prepared by melting pure salts at low temperatures, then dried and stored in glove boxes to protect them from water and oxygen. The oxidation and decomposition processes were characterized by thermogravimetric analysis. Ion chromatography was used to measure the proportion of nitrite ions, and potentiometric titration was used to determine oxide content. Prior to the formal experiments, all three testing methods underwent error calibration to ensure the accuracy of the test results. The thermogravimetry test conducted in a synthetic air atmosphere explains the reason why Hitec salt has a higher decomposition temperature (with 3% weight loss) than Solar salt. At high temperatures, Hitec salt first reacts with oxygen and gains weight at 450 ℃ before decomposition and subsequent weight loss because of its high initial concentration of nitrite ions. In contrast, solar salts begin continuous decomposition and weight loss at 500 ℃, generating oxygen and nitrogen oxides. This analysis indicates that the components of Hitec salts are more prone to change at high temperatures, which increases their melting point. Therefore, it cannot be used at higher temperatures. Long-term stability tests conducted in a muffle furnace revealed that, at high temperatures, Solar and Hitec salts produce approximately the same nitrite ratio after equilibrium. This is attributed to their similar Na⁺ to K⁺ ratios, which lead to similar chemical equilibria. Under an air atmosphere, the proportion of nitrite ions increased with temperature, rising from 4.36% (molar fraction) at 550 ℃ to 7.34% at 600 ℃. The test results on the formation of oxides at high temperatures showed that, in the open system, the Hitec salt continuously decomposes and produces oxides at 580 ℃. This result can be attributed to the direct emission of gaseous products. At 200 h, the oxide mass fraction of Hitec salt reached more than 9%, with obvious oxide precipitation. These findings demonstrate that the use of nitrate molten salts at higher temperatures may require the consideration of a closed system to inhibit oxide formation.

Thermal runaway of lithium-ion batteries (LIBs) is a significant safety concern because of the release of highly toxic and flammable gases. These hazardous emissions can increase the risk of asphyxiation and cause serious fire accidents. Therefore, using gas detection for early warning of thermal runaway is crucial for the safety design of battery cells and packs. In this study, a laser Raman spectroscopy analyzer was used to detect the composition and concentration of thermal runaway gases emitted by LIBs with different cathode materials at various states of charge (SOC). The results demonstrate that the gas signal of a lithium iron phosphate battery (LFP) is primarily concentrated between the opening of the battery valve and thermal runaway under different SOC conditions. In contrast, nickel cobalt manganese batteries (NCM) mainly showed gas signals after thermal runaway. These findings indicate that H₂, CO, CO₂, CH₄, and C₂H₄ are theoretically feasible as characteristic gases for providing early warning of thermal runaway in batteries. Based on the experimental results for the battery cells, the above characteristic gases were further used for thermal runaway gas detection and early warning verification in the battery packs. A composite gas sensor that can measure CO₂ and CO/H₂/HC concentrations in real-time was used to detect characteristic gas changes at different locations inside battery packs. The gas concentration information was collected and uploaded to the battery management system (BMS). Compared with traditional cell temperature and voltage monitoring, gas signals provide a practical and effective method for the early warning of thermal runaway in battery packs. The results demonstrate that: ① the gas signal is negatively correlated with the distance between the sensor and the thermal runaway trigger battery. ② The CO/H₂/HC signals are faster than CO₂. Remarkably, even at the farthest detection location, CO₂ gas can send an alarm signal at least 578 s before thermal runaway, demonstrating the effectiveness of gas-based early warning. ③ Compared with the temperature and voltage of traditional BMSs, gas signals offer a considerable competitive advantage for thermal runaway warnings. This study investigates gas generation during the thermal runaway process in LFP and NCM battery cells to verify the gas-based early warning system in their corresponding battery packs. The results demonstrate that gas-sensing technology can provide timely warning of thermal runaway in both LFP and NCM battery packs, providing a crucial reference for the development of LIB thermal-runaway early warning technology.

Abstract: During power restoration in a distribution network, some devices may experience problems such as overcharging or overdischarging because of the differentiated characteristics of the SOC (state of charge) of various battery energy storage devices. These problems pose a threat to the stable operation of the distribution network. A power restoration active control method that considers the state of charge (SOC) characteristics of battery energy storage is proposed to better utilize the active power support capability of energy storage during power restoration in the distribution network. First, the dynamic response capability of distributed photovoltaics and energy storage systems was considered based on the frequency response characteristics of distributed photovoltaics and battery energy storage. An active power control model was then established for power supply recovery scenarios in the distribution network. Then, the analytical relationship between the energy storage SOC and the frequency modulation coefficient was analyzed, and a frequency modulation coefficient constraint was constructed considering the characteristics of the energy storage SOC. Accordingly, the capacity limitation of energy storage and the state space equation of the distribution network were examined, and a method for the collaborative optimization of the energy-storage frequency modulation coefficient was developed, wherein the optimization objective function to be minimized was the frequency deviation. Finally, the frequency modulation performance of the control strategy before and after optimization was compared via Matlab/Simulink simulations. The results showed that the algorithm achieved higher control accuracy and faster response speed after optimization. Thus, the frequency modulation capabilities of each energy storage unit were fully utilized, enhancing the active power control performance during the power supply recovery process of the distribution network.

Against the backdrop of China's "Dual Carbon" goals, the hydrogen energy industry has become a key carrier for energy transformation. Taking Ordos City as the research area, this study examines the status, core issues, and optimization paths of hydrogen energy industry development within the theoretical framework of policy-driven and technological innovation. Through literature analysis, case studies, and cost-benefit models, the research reveals that Ordos City, leveraging its abundant renewable energy resources and industrial cluster, initially established a "wind-solar-hydrogen-storage-vehicle" industrial chain. However, bottlenecks, such as high costs of green hydrogen, weak infrastructure, and a shortage of technical talent, persist. The study proposes that through policy coordination, technological iteration, and application-scenario expansion, a green hydrogen economic closed loop should be constructed to promote the advancement of the hydrogen energy industry from a demonstration state to large-scale applications. This paper provides theoretical references and practical inspirations for the low-carbon transformation of resource-based cities.

Toward the goal of "reaching the peak of carbon and carbon neutrality," China is vigorously developing renewable energy and actively developing energy storage technology to address the critical problems of supply and demand imbalance—space-time difference, intermittence, and instability. Thermochemical adsorption heat storage offers the advantages of high heat storage density and low heat loss, making it one of the most promising heat storage technologies. Zeolite is well-known for its applications in adsorption and heat storage, but it has the disadvantage of relatively low heat storage density. Impregnating zeolite with hydrated salts can effectively address these problems. However, systematic research on the optimal ratio of hydrated salts in zeolite/hydrated salt composites is lacking. In this study, zeolite was impregnated with four commonly used hydrated salt materials, namely, MgSO₄·7H₂O, MgCl₂·6H₂O, LaCl₃·7H₂O, and CaCl₂·2H₂O. Adsorption and heat storage materials composed of zeolite/hydrated salt with different mass fractions were then prepared. The adsorption properties, heat storage density, and cycling properties of these materials were examined comprehensively. The results showed that the optimum mass fraction of MgCl₂ impregnated with zeolite was 30%. This material achieved the best adsorption performance (44.99%) and the highest heat storage density (638.9 J/g) at 80% relative humidity (RH). The second-best performance was achieved by MgSO₄ impregnated with zeolite, which had an adsorption mass of 38.0% and a heat storage density of 568.5 J/g at 80% RH. The results of subsequent cyclic experiments showed that the zeolite composite impregnated with 10% MgSO₄ had the best cyclic stability but lower adsorption property and heat storage density than the zeolite/MgCl₂ heat storage material with a 30% mass fraction. This work will support research on zeolite/hydrated salt composites and provide a reference for the performance improvement and application of zeolite heat storage materials.

The state of charge (SOC) of lithium batteries is a critical parameter for battery management systems. However, SOC cannot be measured directly because it is strongly coupled to the intricate electrochemical characteristics of the battery. Although data-driven methods recently demonstrated significant potential in SOC estimation, their accuracy depends greatly on the precision of input data. SOC estimation of lithium iron phosphate (LiFePO₄) batteries is challenging because the battery exhibits voltage plateau characteristics: voltage fluctuations and noise substantially degrade the estimation reliability. To overcome this challenge, this study proposes a hybrid experimental and data-driven approach that incorporates battery expansion force as a novel input dimension, thereby synergizing the electrochemical and mechanical properties of the battery to mitigate the impact of voltage plateau on SOC estimation. Experiments were conducted at four environmental temperatures and under two dynamic current test conditions. The acquired data were used to train and validate neural network models for evaluating the SOC estimation accuracy and to verify the feasibility and robustness of the proposed method. Furthermore, a hybrid model combining a convolutional neural network (CNN) and a bidirectional long short-term memory (Bi-LSTM) network was developed to simultaneously capture local temporal patterns and long-term dependencies in sequential data, further enhancing the SOC estimation reliability. The results indicated that the proposed method remarkably improved the SOC estimation accuracy for LiFePO₄ batteries, achieving an average reduction of 43.82% in the root-mean-square error (RMSE) compared to methods that did not incorporate expansion force signals. Moreover, the CNN-BiLSTM model outperformed conventional neural network models, achieving a maximum RMSE reduction of 53.88%. Thus, this study provides a novel perspective for high-precision SOC estimation and offers valuable knowledge for advancing the performance of battery management systems.

Energy storage system is the core part of modern power resources, so its correct performance evaluation is the key to ensuring power supply. With the current technological development of energy storage systems, traditional experimental evaluation strategies based on physical models are no longer able to meet application requirements. As a relatively advanced data-driven algorithm at present, data mining algorithms provide new ideas for the performance evaluation of energy storage systems. This article first introduces the research progress of data mining algorithms, including data processing research, data algorithm optimization research, and deep learning; On this basis, the evaluation process of energy storage systems under data mining is further elaborated. It has been proven that data mining technology can correctly, timely, and effectively extract a large amount of energy storage data information, capture its risk issues, and provide important data support for the healthy operation and monitoring of the system.

This study takes the issue of internal faults in lithium batteries as the starting point and proposes an internal fault analysis strategy for lithium batteries based on the Isolation Forest algorithm. It not only explains the impact of lithium battery faults on their operational safety, but also explores the feasibility of applying the Isolation Forest algorithm. Analyze the necessity of fault data collection and preprocessing, and based on this, construct an isolated forest algorithm model. Then, elaborate on the effectiveness of the designed method from three aspects: anomaly score calculation, fault determination, and fault diagnosis.

With the development of new power systems, the capacity configuration of energy storage systems and power demand forecasting face high uncertainty and complex coupling relationships. To address this challenge, this paper proposes a machine learning-based collaborative modeling strategy, theoretically constructing a three-stage capacity planning framework of "estimation-confidence-feedback." By integrating deep learning and ensemble regression methods, a multi-scale, multi-quantile load forecasting system is established. Through rolling optimization and adaptive updating mechanisms, dynamic linkage between capacity and demand, as well as system self-learning, are achieved. This method emphasizes data-driven and closed-loop strategies, improving forecasting accuracy, capacity adaptability, and model robustness, providing theoretical support for the intelligent configuration of energy storage systems in dynamic environments.

This bimonthly review paper highlights 100 recent published papers on lithium batteries. We searched the Web of Science and found 4922 papers online from Apr. 1, 2025 to May 31, 2025. 100 of them were selected to be highlighted. Layered oxide cathodes including Ni-rich oxides are still under extensive investigation for the modification of doping and coating. For alloying mechanism anode materials, beside 3D structure design, many researchers pay attention to the binders. The studies of solid-state electrolytes are mainly focused on synthesis, doping, structure design and stability of pre-existing materials and developing new materials. For liquid electrolytes, the optimal design of solvents and lithium salts for different battery systems and the test of new functional additives are drawn large attentions. While more research papers related to solid state Li-S batteries have appeared, the design of composite cathodes and the modification of interfaces of solid state batteries are continually being extensively investigated. The works for liquid electrolyte lithium-sulfur batteries are mainly focused on improving the activity of sulfur and suppressing the "shuttle effect". As for other liquid electrolyte battery technology, it focuses on the new technology for making electrodes, and the inhibition of lithium interface dendrite and side reactions. There are also a number of papers on the measurement,analysis and theoretical calculations of electrode materials and electrolytes.