Addressing the issue of low energy density and complex preparation process associated with supercapacitor electrode materials, this study capitalizes on the high specific surface area and porous structure of MOF materials. Bimetallic NiMn-MOF nanosheets with a three-dimensional pore network structure were prepared through a simple and controllable one-step hydrothermal method. The close atomic radius of Ni and Mn proved beneficial for synthesizing bimetallic NiMn-MOF, exposing additional active sites. The optimization of process parameters resulted in bimetallic NiMn-MOF electrode materials with high specific volumes. The morphology and crystal structure of the electrode materials were characterized in detail via scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. The electrochemical properties were also analyzed using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The results showed an impressive specific capacitance of 1023.5 F/g at 0.5 A/g in a 6 mol/L KOH electrolyte. Additionally, an assembled asymmetric supercapacitor delivered a capacitance of 94.37 F/g at 0.5 A/g, successfully powered a red LED. This outcome underscores the excellent electrochemical performance of NiMn-MOF, offering a new approach to preparing electrode materials for supercapacitors.

In the context of carbon neutrality goals, large-scale, long-duration energy storage is crucial for developing modern power systems primarily based on renewable energy. Zinc-bromine flow batteries, known for their low cost and high energy density, hold great promise in energy storage. As a semi-deposited battery, the size of zinc deposition areal capacity considerably impacts both the energy storage duration of the battery and its economic viability. Herein, highly conductive bipolar plates were employed, and defect engineering was implemented on the surface of the negative electrode of the zinc-bromine flow battery. This optimization successfully enhanced the cell structure of the battery and negative electrode, resulting in the outstanding battery performance under high areal capacity conditions. Furthermore, through characterization and comparison using methods such as scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and Galvanostatic charge-discharge testing, moderately oxidized graphite felt was identified as the optimal electrode material. When combined with the optimized cell structure, the moderately oxidized graphite felt achieved remarkable performance. At a current density of 20 mA/cm² and an areal capacity of 120 mAh·cm^-2, the battery demonstrated an impressive 94.26% Coulombic efficiency and 82.12% energy efficiency. Finally, this study elucidates the mechanism behind this optimization strategy. The optimized cell stack structure considerably improves the distribution of internal currents in the battery, especially under low areal capacity conditions. As the areal capacity increases, achieving flat and dense zinc deposition while preventing zinc dendrite formation necessitates the integration of zincophilic defect engineering on the negative electrode surface. By integrating the optimized cell stack structure with the negative electrode material, exceptional battery performance is realized under high areal capacity conditions. This study provides robust support for the future application of zinc-bromine flow batteries as long-duration energy storage devices.

The electrode is an important part of the iron-chromium flow battery, serving as the site where the active components in the electrolyte undergo electrochemical reactions. The ideal electrode material should have high conductivity, large specific surface area, high electrochemical activity, low cost, among other characteristics. However, current electrode materials often lack a balance of these characteristics. Metal-organic frameworks (MOFs) combine their advantages of high conductivity and high catalytic performance, providing additional active sites for electrochemical reactions and finding widespread use in electrode materials. Herein, bismuth-based carbon cloth (CC) electrodes (C-Bi/CC) with carbon cloth-supported Bi-MOF as a precursor (Bi-MOF/CC) were prepared using a hydrothermal method. The electrode performance was improved by exploring the coupling correlation between the addition of metal salts and the electrode performance. The results showed that the electrode sample using 90 mg of metal salt and the ordinary carbon cloth as the positive electrode exhibited the best electrochemical performance, with a reduced polarization resistance of 1.069 Ω (an 8.5% reduction), an enhanced electrochemical active area, a low Cr³⁺ reduction overpotential of 0.25 V (a 59.7% decrease). The modified electrode was used as the negative electrode of the iron-chromium flow battery for the battery cycling performance test. At a current density of 80 mA/cm², the energy efficiency reached 89.7%, the Coulombic efficiency was 97.2%, and the voltage efficiency was 92.3%. At a current density of 140 mA/cm², the energy efficiency remained high at 83.8%, with the Coulomb efficiency reaching 98.1% and the voltage efficiency reaching 85.5%.

The proton exchange membrane fuel cell (PEMFC) serves as a widely used power generation device in transportation, energy storage, aerospace, and military applications owing to its high energy-efficient conversion rate, clean operation, and reliability. To address the challenges of PEMFC, specifically its high heat dissipation density, high heat generation, and low heat dissipation efficiency, an experimental bench for an automotive fuel cell heat dissipation system was constructed. This system incorporated four different flow heat exchangers, catering to a 15 kW PEMFC with a heat dissipation issue. The experimental setup employed two-phase cooling mediums, namely HFE-7100 and an aqueous ethylene glycol solution. The investigation focused on their thermal performance and system energy efficiency rating under different process heat exchangers and various medium flow rates at 35 ℃. The results showed that under the same flow path, HFE-7100 two-phase cooling medium exhibited an improved heat dissipation rate between 81.2% and 98.8%, with a system energy efficiency ratio (EER) improvement rate between 68.2% and 88.6% compared with ethylene glycol aqueous liquid cooling. Among the four different flow paths, flow path 3 demonstrated the best system heat dissipation and EER. Specifically, HFE-7100 two-phase cooling achieved heat dissipation and system EER of 14.4 kW and 20.5 kW/kW, while ethylene glycol aqueous liquid cooling reached 7.7 kW and 12.1 kW/kW, respectively. At a cooling medium flow rate of 4 L/min, the system exhibited better energy-saving effects, with the two-phase and liquid-cooling heat dissipation system EER reaching 20.9 and 10.5 kW/kW, respectively.

In addressing the problems of low thermal conductivity and susceptibility to leakage in phase change materials within solar photovoltaic thermal (PV/T) systems, composite shape-stabilized phase change materials comprising docosane-dodecanol and expanded graphite were prepared and their properties were experimentally studied. Herein, docosane-dodecanol phase change materials were prepared in the ratio of 6∶4, followed by the preparation of a series of composite shape-stabilized phase change materials with different expanded graphite contents through a melt blending method. In the experiment, the microstructure was observed using field emission scanning electron microscope, and various parameters such as latent heat and thermal conductivity were measured using a heat flow differential scanning calorimeter and a thermal conductivity measuring instrument, respectively. The physical compatibility, adsorption, and cycle stability of the material were also studied. The optimum ratio of expanded graphite and docosane-dodecanol and its various properties were explored. The results show that the composite shape-stabilized phase change material exhibits optimal performance when the mass fraction of expanded graphite is 15%. At this composition, the expanded graphite is sufficient to adsorb the phase change material, resulting in a permeability of only 3.85% with no noticeable exudation. The latent heat of melting and solidification phase change is 203.8 and 196.6 kJ/kg, respectively. After 50 cooling and heating cycles, minimal changes are observed in phase transition temperature and latent heat, and the thermal conductivity remains stable with a fluctuation range of only 5.9%. Additionally, the mass loss is only 0.0495 g, which shows good cycle stability. This research provides valuable theoretical data support for the subsequent application of shaped phase change materials in solar PV/T systems.

This study aims to investigate the influence of different boundary temperatures on the heat storage performance of the phase change energy storage unit (PCESU) by conducting visual experiments on the melting process of phase change material (PCM) in a double-fin rectangular PCESU at different boundary temperatures. The analysis involves examining the melting behavior and heat transfer process based on the observation of the solid–liquid interface, PCM temperature, and liquid fraction. The results show that during the late melting stage, solid PCM accumulated at the right-bottom of the PCESU, extending the heat storage time, with the melting time ratio of the PCM at this stage exceeding 30%. With the increase of boundary temperature, the shape of the solid-liquid interface remains considerably constant, with temperature distribution variation being similar. However, the evolution process of the solid-liquid interface accelerates, and natural convection is enhanced, leading to a 60% increase in the nonuniformity of the temperature distribution in the PCM. Moreover, the phase transition temperature increases by a maximum of 2.9 ℃. The results demonstrate that when the boundary temperature increases from 50 ℃ to 73 ℃, the complete melting time is shortened by 510 min. Lower the boundary temperature, greater the \frac{Fo}{Ste}, indicating that increasing the boundary temperature has a pronounced effect on heat transfer enhancement of the PCM at a lower boundary temperature.

The performance of the printed circuit heat exchanger (PCHE), an important component in the supercritical carbon dioxide (S-CO₂) Brayton cycle, affects the efficiency of the system. This study aims to improve the performance of airfoil PCHE by investigating the effect of the airfoil-fin structure on its flow and heat transfer performance. Herein, for the high-temperature return heaters in the S-CO₂ Brayton cycle system, a numerical simulation method is used, with S-CO₂ selected as the heat transfer medium. By comparing the flow and heat transfer performance of the airfoil-fin channels of NACA0020 with three different structures, we study the influence of the positional parameter of the maximum thickness of the airfoil fins on the chord length on the performance of the heat exchanger and analyze the rule of change in terms of the thermo-hydraulic performance, comprehensive indexes, overall fluidity, local performance, etc. Results show that the heat transfer performance increases as the maximum thickness of the airfoil fins approaches the leading edge of the airfoil along the chord length while maintaining a constant relative thickness in the airfoil-fin structure. Compared to the other two airfoil-fin channels, the airfoil-fin channel of NACA0020-20 exhibits a larger j factor and Nu of 2.7%—8.8% and 2.7%—8%, respectively, under the selected operating conditions. This airfoil-fin structure can effectively reduce the influence of the boundary layer and improve the heat transfer performance in the PCHE. Overall, its performance is even better than the other two airfoil fins. These results provide a certain basis for the structural design and performance optimization of the airfoil PCHE.

To elucidate the competitive correlation between metal honeycomb heat conduction and natural convection heat transfer in the liquid phase during the melting heat storage process of metal honeycomb/paraffin composite phase change material (PCM), a computational model based on the fluid-solid-thermal coupling theory was established. The phase change paraffin melting test was conducted to verify the effectiveness of the proposed computational model. Furthermore, the enhancement effect of metal honeycomb heat conduction and natural convection heat transfer in the liquid phase were analyzed, along with their competitive correlation. The results show that the heat storage process of phase change paraffin melting in a square cavity under bottom heating can be divided into four stages: heat conduction, steady growth, transition, and turbulence. The proportions of each stage in the total melting time are 0.8%, 2.3%, 13.6%, and 83.3%, respectively. Barrier-free heat transfer is realized with the natural flow of liquid paraffin, improving the thermal storage efficiency of phase change paraffin. The enhancement effect of natural convection heat transfer is considerably weakened with the decrease in size and becomes negligible when the size is less than 2 mm. Increasing the thermal conductivity and heat transfer area of the metal honeycomb can improve the thermal storage efficiency of phase change paraffin. After embedding the metal honeycomb, a multilayer melting phenomenon occurs in the PCM heat storage process, creating a temperature gradient in the melting zone. Compared with the heat storage efficiency of pure paraffin, the effect of the metal honeycomb is first enhanced and then inhibited. When the melting fraction exceeds the critical value 0.77, the metal honeycomb enters the inhibition stage.

In the context of comprehensive electrification, the rapid transformation of various electronic products in time and space domain has imposed demanding working conditions and environmental adaptation requirements on the power supply capacity of equipped batteries. There is an urgent need to develop power systems with short charging times, small volumes, and large current outputs. In this review, the development of high-power chemical power supply systems with high-rate charge and discharge, a topic of widespread concern in recent years, is reviewed. The systems under consideration include lithium-ion batteries, sodium-ion batteries, pseudocapacitors, ionic capacitors (lithium/sodium/potassium ion, etc.), and lead-carbon batteries. The review is approached from the perspectives of electrode materials, electrolyte regulation, and battery structure. The focus is on analyzing the developmental bottlenecks and current solutions influencing the power performance of these diverse power supply systems. The review covers the current developmental levels, technical capabilities, and key technologies requiring breakthroughs for each technology system. Military applications and equipment effectiveness are also explored in low-temperature starting, power supply, and pulse response. The comprehensive analysis shows the importance of selecting a chemical power supply system with superior performance and compatibility to serve the iterative upgrading and application innovation of equipment in different scenarios. To address challenges, it is emphasized that reducing internal resistance through the construction of electrode materials with high stability and conductivity, implementing electrolyte materials with a wide temperature range and high conductivity, and improving battery structure can considerably improve power performance. This review identifies the issues related to the optimal working range and strategy for high-power batteries, especially under high-current charging and pulse conditions, which is crucial for optimizing battery use according to actual working conditions in the future. The outlook anticipates advancements in the power performance of each chemical power supply system, along with improved cycle life, energy conversion efficiency, safety, and reliability of the batteries. Achieving these goals will require the implementation of the best system management and control methods and application strategies. This holistic approach aims to obtain high-power power supply products that meet market needs and are urgently needed by the military and civilians.

With the rapid development of consumer electronics, electric vehicles, and large-scale energy storage industry, high requirements for the safety and efficiency of electrochemical energy storage technology. However, safety hazards associated with lithium-ion batteries limit their application in the energy storage market. Aqueous dual-ion batteries (ADIBs) have emerged as a new energy storage device that uses an aqueous electrolyte as the ion transport medium. In ADIBs, anions and cations in the electrolyte act as carriers, simultaneously participating in the electrode electrochemical reaction. ADIBs show potential application prospects in large-scale energy storage owing to their remarkable advantages, such as excellent safety performance, high power density, eco-friendliness, and high cost-effectiveness. This review delves into the working principle of ADIBs and addresses key scientific issues limiting their further development. The authors summarize various strategies to broaden the electrochemical stable voltage window, focusing on recent advances in electrolyte design. Then, the important progress made in optimizing cathode and anode materials and their energy storage mechanisms are elaborated. Finally, based on the knowledge and understanding of ADIBs, future research prospects and directions are proposed. Therefore, this study aims to provide a valuable reference for researchers in aqueous energy storage technology. This review contributes to promoting the development of ADIBs and accelerating progress in high-safety energy storage.

Phase change cold storage technology, as a new type of energy storage method, has received widespread praise in the field of food cold chain logistics. To promote efficient energy storage methods and achieve rapid storage of cold energy resources, research is being conducted on the application of phase change cold storage technology in food cold chain logistics. Analyze the classification and technical connotation of phase change cold storage technology, and establish a specific low-temperature energy storage system. Based on this system, analyze the application performance of phase change cold storage technology in food cold chain logistics from two aspects: improving energy storage efficiency and ensuring energy storage safety.

Finite element models were created for stacked automotive supercapacitors using COMSOL Multiphysics 6.0, and thermal models were developed for two different thermal management methods, air- and liquid-cooled, to compare their effects on thermal management. First, the correlations between the maximum temperature of air- and liquid-cooled supercapacitors and the initial temperature of the heat exchange medium, inlet flow rate, and heat generation power of the supercapacitor modules were investigated within the same parameter variation range. The results show that the higher initial temperature of the heat transfer medium and greater heating power of the supercapacitor lead to higher maximum temperatures of the supercapacitor. Conversely, a faster average flow rate of the heat exchange medium at the inlet results in lower maximum temperatures of the supercapacitor. A critical flow rate of 1.5 m/s exists, beyond which the correlation between flow rate and maximum temperature weakens greatly. Second, based on the parametric study results, the heat transfer processes of these two thermal management methods were analyzed in-depth by setting the same operating parameters. This analysis explains opposite heat gradient direction in the height dimension between air- and liquid-cooled methods. The comparison of thermal management effects of the two methodsincludes factors such as maximum temperature, temperature difference, temperature distribution, and heat exchange time. The results show that liquid-cooled supercapacitors exhibit lower maximum temperatures, smaller temperature differences, more uniform temperature distribution, and much less heat exchange time compared to air-cooled supercapacitors and have better thermal management effects.

With the continuous development of UAV technology, its application in the field of high-voltage transmission line inspection is increasingly extensive. As the main power supply device of UAV, fuel cell has many application advantages such as long endurance and high energy density. Based on the above background, the application of fuel cell in UAVS high-voltage transmission line checking system is studied. By analyzing the composition and working principle of the fuel cell, and studying the charging characteristics of the positive and negative electrode materials respectively, the structural model of the fuel cell has been thoroughly studied. On this basis, the practical application of fuel cell in UAS high-voltage transmission line checking system is analyzed from two aspects of high efficiency and low pollution.

The thermal runaway propagation (TRP) of Li-ion batteries poses a substantial fire and explosion risks, preventing their further widespread application. Herein, glass fiber aerogel and ceramic fiber mats are used to suppress the TRP in batteries, exploring the influence of the type and thickness of the insulation material on the suppression effect. Two module layout methods are designed: single barrier and spacer barrier modules. The former involves placing a piece of insulation material in every other battery, while the latter involves placing a piece of insulation material in every two batteries. Research results show that in a single barrier module, glass fiber aerogels with a thickness of 2 and 1 mm can effectively prevent TRP, and the temperature rises of the front and back surfaces of the protected battery are 193.6℃, 86.1 ℃, and 222.6 ℃, 86.8 ℃, respectively. However, a 2 mm-thick ceramic fiber felt can only delay the speed of TRP butnot completely prevent it. In the spacer barrier module, using a 2 mm glass fiber aerogel as a barrier results in a temperature rise of 168.3 ℃ and 56 ℃ on the front and back surfaces of the protected battery, demonstrating that the spacer barrier module offers an enhanced protective effect on the battery under abuse conditions. To a certain extent, the results of this study alleviate the contradiction between the use of thermal insulation materials and the energy density of modules. The findings hold important theoretical guidance for the safety design of lithium-ion battery modules.

The electrochemical energy storage power station has been gradually applied on a large scale in a high proportion of the new energy power grid, and its optimal configuration strategy largely determines the effectiveness of frequency and voltage regulation in its auxiliary power grid. To realize the optimal configuration of the electrochemical energy storage power station, this study first examines the control strategy of energy storage participating in the frequency and voltage regulation of the power system under a high proportion of new energy. It proposes a control method based on the variable coefficient frequency-voltage sag. Then, the multi-objective optimal configuration model for the energy storage system participating in the frequency and voltage regulation of the power grid under a high proportion of the new energy grid is established. The model considers the comprehensive indices of frequency modulation, voltage regulation, and system cost as optimization objectives. The improved multi-objective particle swarm optimization algorithm is employed to optimize the configuration of control parameters and the location and capacity of the energy storage system. To address subjectivity in the data, the entropy weight method is used to select the optimal scheme from the obtained multi-objective solution set. Finally, a practical example of a regional power grid of a city is used to optimize the allocation of energy storage. The comprehensive indices of regional power grid voltage regulation and frequency modulation were reduced by 9.2% and 25.1%, respectively. The voltage and frequency deviation of regional power grid nodes was considerably reduced, improving the effect of voltage regulation and frequency modulation. This verifies the effectiveness and superiority of the proposed energy storage fixed capacity location allocation method.

This study addresses the issue of neglecting the impact of internal battery cell structures on the thermal performance of energy storage battery systems in current thermal management simulation studies. This study introduces a refined thermal design concept, proposing a temperature uniformity distribution approach based on perforations in the battery pack enclosure. This study utilizes computational fluid dynamics simulation methodology to comprehensively assess the influence of perforation sizes and quantities on battery thermal performance. Subsequently, optimized designs for the battery enclosure are selected. The research findings reveal that, in optimizing individual battery enclosures, superior performance is achieved by introducing perforations on the lateral walls rather than the upper surface. This advantageous strategy reduces the temperature difference within a single battery from a prior 6.01 to 3.68 K, resulting in a substantial 28.2% decrease and effectively meeting the heat dissipation requirements of the battery. Moreover, at the scale of the entire battery stack, the implementation of lateral wall perforations leads to a substantial reduction in the maximum temperature difference within a single column of battery cells from 7.66 K to 4.32 K, representing an impressive enhancement of 43.6%. Through a coupled thermal analysis of the external air ducts and the internal structure of the battery pack, this study provides valuable insights for future thermal management strategies in energy storage battery systems.

The urban railway system provides convenient access to urban and suburban areas. The stations along the railway lines offer parking facilities for electric vehicles (EVs) with park-and-ride scheme and serve as a convenient interface for EVs to connect with the railway traction power system. To improve the utilization rate of regenerative braking energy in trains and reduce the operating cost of urban railways, this study proposes an optimal operation model for co-phase traction power substations in conjunction with EVs in urban rail. The primary objective of this model is to minimize the daily electricity cost of the traction substation (TS) by optimizing the charging and discharging strategy of EVs and ultracapacitors, as well as the power regulation strategy of the TS. To address the uncertainties associated with EV arrival time, departure time, and initial charge state, chance-constrained programming ensures that the EV charging scheme meets the driving requirements at a higher confidence level using probabilistic constraints than the predetermined confidence level of traditional deterministic constraints. The model is formulated as a mixed integer linear programming model by converting chance constraints into deterministic constraints using sample average approximation, and the model is subsequently solved using the CPLEX solver. Simulation analysis shows that the proposed model can effectively reduce the daily electricity cost of the TS by 20.37%, which reflects the feasibility of EVs in participating in the load regulation of the traction power supply system, thereby effectively improving the operating economy of the system.

In recent years, there has been a substantial increase in number of lithium battery energy storage power stations globally, with high user-side potential. This surge in installations has elevated safe requirements for lithium battery energy storage power stations. The traditional early warning system for fire using fire detectors is insufficient for lithium battery energy storage cabins. Numerous domestic and international studies show that heptafluoropropane and perfluorohexanone are currently more suitable as fire extinguishing agents for lithium battery energy storage power stations. However, no single fire extinguishing agent can simultaneously extinguish open flames and inhibit the re-ignition of large-capacity lithium batteries. Presently, lithium battery energy storage power stations lack clear and effective fire extinguishing technology and systematic solutions. Recognizing the importance of early fire detection for energy storage chamber fire warning, this study reviews the fire extinguishing effect of water mist containing different types of additives on lithium battery energy storage power station fires. Highlighting the importance of the joint application of gas fire extinguishing agents and water mist in firefighting strategy, this study proposes key considerations and outlines the next development direction for developing clean and efficient fire extinguishing technology.

As a promising energy storage system, Li-ion batteries require continuous improvements in terms of energy density, power density, reliability, and cyclic stability to meet the growing demands of large-scale energy storage, electric vehicles, and portable electronic equipment. Despite the abundance of frontier issues related to multiphysics investigations, experimental work is still challenging. However, the synergistic improvement in the conductivity and safety of electrolytes, optimization of deposition-stripping mechanisms of high-energy anodes, maintenance of cyclic voltage and capacity of high-energy cathodes, interface polarization, and capacity release under high current, and management of thermal runaway under extreme current-temperature-acupuncture conditions exist through the multifield coupling of electrical-chemical-mechanical-thermal effects. COMSOL multiphysics provides a feasible tool for solving the continuity equation coupled with multiple physical fields, considering comprehensive information such as carrier concentration, current density, electrical-chemical potential, temperature, stress/strain, and morphology evolution. This study reviews the application of tools in the electrolytes, anodes, and cathodes of lithium-ion batteries, focusing on the comprehensive influences of multifield coupling on battery performance, the multifield coupling simulation method, and the combination of theoretical, simulation, and experimental characterization. Finally, the multifield and multiscaled issues in theoretical-experimental joint research are prospected.

With the proposal of the "dual carbon" goal, the distribution station area is connected to many new elements, such as distributed photovoltaics, electric vehicles, microgrids, and smart buildings, posing challenges to the safe operation of medium- and low-voltage distribution networks and offering considerably flexibility potential. Taking smart buildings connected to the distribution station area as an example, this study proposes a multi-time scale optimal scheduling method for a building microgrid considering a virtual storage system. Firstly, the thermal dynamics of the envelope of the building is modeled, and a virtual energy storage model that quantitatively describes the flexibility of buildings are constructed. The flexibility of buildings can be used by optimizing the charging and discharging powers of the virtual energy storage. Then, the adjustable virtual energy storage characteristics of buildings are considered in detail in the multi-time scale optimal scheduling model of flexible resources in distribution stations. The proposed multi-time scale optimal scheduling model can leverage the virtual energy storages at day-ahead and the intra-day stages. A day-ahead economic scheduling method aiming at the lowest operating cost and an intra-day correction method for tracking the setting value of the microgrid contact line is proposed. Finally, taking the cooling scenario in summer as an example, the effectiveness of the proposed multi-time-scale optimal scheduling method is verified using a typical building microgrid system. The results show that this method can effectively schedule the virtual energy storage capacity of the building, reduce the operating cost of the building microgrid in the day-ahead operation stage, and effectively mitigate the random fluctuation of renewable energy in the intra-day stage.

In rapid charging and discharging process, power lithium batteries generate a substantial amount of heat, posing the risk of heat accumulation and thermal runaway. Therefore, thermal management is essential for battery safety. This study first establishes an electrochemical-thermal coupling model for batteries and investigates the temperature rise characteristics of batteries. Then, a battery thermal management system based on composite phase change materials (CPCMs) is designed to regulate battery temperature during high-rate discharge. Finally, the temperature control effect of the battery thermal management system on battery temperature and temperature difference is compared under different battery spacing conditions. The numerical simulation results show that during the 3 C rate discharge process of a single battery, the maximum temperature of the battery is 58.9 ℃. However, using phase change materials for battery cooling, even at an ambient temperature of 35 ℃, the maximum temperature and temperature difference of the battery can be effectively controlled at 46.1 ℃ and 3.6 ℃, respectively, thereby ensuring safe operation of the battery, extending the service life of the battery pack, and improving battery safety performance. Moreover, the analysis of the solid-phase ratio of CPCMs shows that maintaining a non-zero solid-phase ratio effectively controls battery temperature and temperature difference. However, when the solid-phase ratio of CPCMs in the thermal management system is zero, the battery pack temperature and temperature difference rapidly increase. Therefore, analyzing the solid-phase ratio index of CPCMs proves beneficial for their application and the optimization of thermal management systems.

Energy storage is a pillar technology for innovative applications of renewable energy. Under the background of the "dual carbon" strategy, energy storage technology has solved the technical difficulties of renewable energy applications and played a role in peak shaving, valley filling, and stable energy supply. This paper first introduces the characteristics of building energy supply systems, and then analyzes the possible problems in long-term energy planning and utilization. Finally, the paper focuses on comparing the advantages and disadvantages of different energy storage technologies, and introduces the specific applications of battery energy storage, hydrogen energy storage, and various hybrid energy storage. By comparing different coupling methods and continuously optimizing energy storage technologies, it will help achieve energy structure transformation and provide effective references for building energy optimization.

Due to its remarkable advantages, the ammonia decomposition hydrogen production and energy storage system are crucial for advancing future dual carbon goals and energy system construction. Herein, the operating characteristics of an ammonia decomposition tubular filled-bed reactor under electrical heating are simulated and incorporated into a power system, considering uncertainties on both sides of the source load. The effects of increased capacity of the installed ammonia decomposition system on the performance indicators of the power system, such as electricity costs, carbon emissions per kWh, share of new energy generation, utilization rate of new energy, and daily hydrogen production, are analyzed under three different power system installation compositions. The results show that the ammonia decomposition system can effectively improve the consumption level of new energy generation. The maximum capacity of the ammonia decomposition system can increase the utilization rate of new energy by 5.5%—62.4% and the share of new energy generation by 14.2%—160.8% under the three compositions; the resulting carbon emissions from electricity generation are reduced by 0.9%—22.8%, and the cost of electricity generation is increased by 7.6%—34.5%. For the three compositions, the daily hydrogen production reaches 39,000, 104,000, and 171,000 tons, respectively. The results of this study can provide a reference for configuring the ammonia decomposition hydrogen storage system in the power system to reduce carbon emission and promote hydrogen energy technology development.

To investigate the influence of fins and copper metal foam on the performance of phase-change energy storage systems, composite phase-change material (PCM) models with 20 and 30 pore per inch (PPI) were constructed using the quartet structure generation set. Additionally, a finned PCM model with an equal copper mass was constructed. Subsequently, numerical simulation based on the lattice Boltzmann method was employed to simulate the heat storage/release process of PCM. The effects of adding fins and foam metal structures on the heat transfer performance of PCM were compared and analyzed based on Nusselt number, liquid fraction, PCM flow rate, and PCM melting/solidification time. The results showed that the presence of foam metal during the heat storage process hindered the development of convective heat transfer during the melting process. The Nusselt number of the double fin structure was higher than that of the foam metal structure, resulting in a shorter melting time for double fin structure. Compared to the 20 PPI and 30 PPI foam copper composite PCMs, the melting time was reduced by 28.55% and 17.5%, respectively. During the heat release process, the presence of foam metal increased the heat conduction area. The solidification speed of the foam metal structure was higher than that of the fin structure, and the solidification time of the 30 PPI foam metal structure was reduced by 65.80% and 20.24% compared to the fin and 20 PPI foam copper composite PCMs, respectively. Considering the heat storage and release processes, the total heat storage/release time of the 30 PPI foam metal structure was the shortest, with reductions of 27.81% and 15.32% compared to the fin and 20 PPI foam copper composite PCMs, respectively. Under the condition of consuming the same amount of metal material, adopting the foam structure is a more effective means to improve energy storage efficiency.

This article is based on the hybrid energy storage system of electric vehicles, combined with its control technology for in-depth analysis. Based on its different characteristics, this design analysis is carried out. The hardware design of the energy storage system mainly involves CAN communication circuit design, etc; The main control chip in the composite energy storage system in this design is selected as the DSPTMS320F2812 chip, and the software design includes multiple stages such as the design of the supercapacitor voltage acquisition program. Experimental tests have found that effective control of motor speed during discharge tests in various modes can enable supercapacitors and batteries to switch to corresponding operating modes, ultimately verifying the design characteristics of this system.

The energy storage process in a conventional diabatic compressed air energy storage (D-CAES) system usually uses more than four compressor units to reduce the consumption of air compression work. However, this leads to a substantial discharge of low-grade compression heat into the environment and serious energy waste. To solve this problem, this study proposes a precooled CAES system that uses organic Rankine cycle-steam compression refrigeration (ORC-VCR) for compression heat recovery (ORC-VCR-CAES). In the proposed system, the compressor inlet air is precooled by recovering the compression heat generated during the air compression stage. This approach further reduces the consumption of air compression work and improves the round-trip efficiency of the system. The thermodynamic and economic analysis of the ORC-VCR-CAES coupling system are also performed. Results show that the choice of ORC-VCR cycle working medium considerably influences system performance. The ORC-VCR-CAES system using R152a as a cycle working medium exhibits the best performance, achieving a system cycle efficiency of 64.15%, which is 5.94% higher than that of the conventional D-CAES system. Moreover, considering external waste heat energy input, the ORC-VCR-CAES system attains an energy efficiency of 51.90%, which is 4.81% higher than that of the conventional D-CAES system. Although the energy loss in coolers is effectively reduced through the recovery of compression heat, the energy loss from compressor units is still large, which is a key equipment for further system optimization. Economic analysis shows that with peak and valley electricity prices at 1.26 and 0.30 CNY, the net present value of the ORC-VCR-CAES system increases by 9.64% compared to the conventional D-CAES system. Compared with the conventional D-CAES system, the percentage increase in the net present value of the ORC-VCR-CAES system is higher when the peak and valley electricity price difference is smaller.

The frequent changes in phase voltage and phase current during the energy storage process are the main reasons why the power cannot maintain a stable state. To solve these problems, a simulation design is carried out for the power storage power regulation system supported by supercapacitor technology. In the main circuit transmission circuit, active filters and grid connected inverters are installed to regulate the energy storage power, and the simulation design of the hardware unit of the power storage power regulation system is completed. Define a supercapacitor model and connect it in a series power circuit, so as to implement equivalent debugging of electrical power while controlling power pulse power, and complete comprehensive adjustment of energy storage power in the power system.

Hydrogen produced through water electrolysis using renewable energy shows promise as a substitute for fossil fuels in transportation and industrial applications, offering a pathway to reduce carbon dioxide emissions. Pressurized water electrolyzers have the potential to generate high-pressure hydrogen and reduce the demand for subsequent hydrogen compressing, which is often necessary for high-density storage and transportation to end-users. This reduction in overall operating expenses and energy consumption results from the diminished reliance on state-of-the-art mechanical compressors and theoretically higher efficiency via isothermal compression in the electrolyzer. However, the increase in hydrogen pressure introduces challenges related to gas tightness, material durability caused by hydrogen embrittlement, safety concerns, and lowered current efficiency attributed to intensified hydrogen/oxygen crossover. These issues impact the large-scale application of pressurized electrolyzers. This study reviews the research progress in high-pressure proton exchange membrane water electrolysis and alkaline water electrolysis. For proton exchange membrane electrolysis, the critical elements for achieving high-performance and durable high-pressure electrolyzers include the development of gas-tight, reinforced, and ion-conductive membranes with an adopted sealing design. Conversely, alkaline water electrolysis requires process innovation and optimization of control strategies to manage hydrogen/oxygen crossover effectively, ensuring safe and efficient high-pressure operation.

To address the issue of abnormal transverse movement in sagger containing cathode materials of lithium-ion batteries during the sintering process in a roller kiln, leading to the sagger to break, this study optimizes the motion process by analyzing factors influencing the abnormal motion characteristics of the sagger. First, Solidworks is used to establish a simplified model of the roller conveyor-sagger transmission system. Force analysis of the sagger reveals that the abnormal transverse movement of the sagger is caused by the elastic deformation of the roller bar. Second, finite element simulation using Abaqus is conducted to compare and analyze the displacement curve of the sagger in the thermo-mechanical coupling field and the gravity field, along with the force exerted on the roller bar. Results show that the thermo-mechanical coupling field induces greater elastic deformation of the roller bar compared to the gravitational field. The transverse displacement of the sagger in the thermo-mechanical coupling field increases relative to the gravity field from 0 to 1 s, while it decreases relative to the gravity field from 1 to 5 s. This indicates that the joint action of temperature and gravity-induced elastic deformation is the primary cause of the abnormal transverse motion of the sagger. On this basis, a sagger transmission mechanism is designed, including the roller bar support mechanism, the sagger clamping device, and the sagger blocking device. The feasibility of the improved mechanism is verified through comparative production. This study analyzes factors affecting the abnormal transverse motion of the sagger during the sintering process in the roller kiln and provides an improved mechanism, contributing to the advancement of cathode material production equipment for lithium-ion batteries.

Under the "dual-carbon" strategic goal, the hydrogen energy industry has undergone rapid and extensive development. The upstream hydrogen production resources are abundant, and the downstream hydrogen market is expansive. However, the cross-regional imbalance in hydrogen energy supply and demand has led to a critical bottleneck in midstream hydrogen energy storage and transportation, hindering the further progress of the hydrogen energy industry. In response to this challenge, liquid organic hydrogen-carrying (LOHC) storage and transportation technology was developed. This method, employing a chemical hydrogen storage approach, perfectly overcomes the defects of physical hydrogen storage methods, such as high-pressure gas hydrogen storage and low-temperature liquid and metal solid methods. Compared with other hydrogen energy storage and transportation technologies, LOHC has outstanding advantages in safety, cost, technology, efficiency, and other aspects. It is expected to address the shortcomings in hydrogen energy storage and transportation, thus enhancing the hydrogen energy industry chain. Herein, three main LOHC storage and transportation technologies, namely methylcyclohexane, N-ethylcarbazole, and dibenzyltoluene, are compared and analyzed from the aspects of process principle, hydrogen storage carrier, comprehensive cost, and research and development. The analysis suggests that these three LOHC technologies, having completed theoretical research, experimental verification, and pilot scale, are poised for industrial popularization and application. In the future perspective, the new application scenarios of two LOHC storage and transportation technologies, including large-scale hydrogen energy storage and transportation bases and distributed dehydrogenation and hydrogenation integrated stations, are analyzed. The challenges and research directions of LOHC storage and transportation technology are summarized while providing hopeful suggestions for the future.

Lithium-ion battery/supercapacitor hybrid energy storage system has become the most widely used hybrid energy storage system because of its good performance, low cost and strong versatility. Energy management method is one of the core technologies of hybrid energy storage systems, and it is also the main research focus at present. In order to systematically review the energy management methods of hybrid energy storage systems, this paper first introduces the topology structure, energy management architecture and power distribution control of lithium-ion battery/supercapacitor hybrid energy storage systems. Then, this paper divides the existing energy management methods of hybrid energy storage system into four categories: experience based, optimization based, working condition pattern recognition based and machine learning based, and the efficiency of each type of energy management methods is discussed respectively for regular and random conditions; the robustness and computational complexity of each method are also analyzed. Finally, the current energy management methods are summarized and the future research directions and development trends in this field are prospected. Comprehensive analysis shows that improving the prediction accuracy of stochastic load in the future, establishing a more accurate hybrid energy storage system model, and further improving the real-time performance of energy management methods through cloud collaboration will be the focus of future energy management research of hybrid energy storage systems.

China has proposed the goal of carbon peak and carbon neutrality to promote the utilization of renewable energy and electrification of heating. Reducing the costs of electric heating has become an urgent need. This study presents a novel heat pump heating system with phase change heat storage. The system charges during surplus renewable energy generation or off-peak electricity and discharges during intermittent periods of renewable energy or peak electricity, achieving thermoelectric decoupling and peak shaving. Owing to the flexibility in utilizing phase change heat storage devices, control strategies can be dynamically adjusted based on the characteristics of renewable energy generation or peak and off-peak electricity periods. This study analyzes the operational performance of the system primarily driven by off-peak electricity and examines the influences of different thermal storage times and capacities on the economy of the system. Experiments were conducted in the high-altitude region of Qinghai. The system with phase change heat storage reduces costs by 5.28% compared to heat pump direct heating. By adjusting control strategies to change the charging time with a storage capacity of 75 kWh, power consumption and operating costs of the system can be reduced by 5.69% and 13.5%, respectively. Increasing the storage capacity to 150 kWh can adjust the peak and off-peak electricity consumption, with the proportion of off-peak electricity reaching a maximum of 84.52%. This further reduces operating costs by 10.04%. The heating system with phase change heat storage demonstrates good economic benefits. The rational utilization of its thermoelectric decoupling characteristics can contribute to the absorption of renewable energy and the stable operation of the power grid.

This paper aims to delve into the application strategy of hydropower station energy storage technology in the integration of renewable energy into the grid. It introduces the rapid development trend of renewable energy and the crucial role of energy storage technology in addressing fluctuation issues. The paper analyzes and discusses the position of hydropower station energy storage technology in renewable energy grid integration, proposing optimization strategies to enhance system stability and economic efficiency. The focus is on the application of hydropower station energy storage technology in improving the utilization of renewable energy, supporting power system dispatch, dynamic scheduling strategies, and system integration. By identifying technological challenges, the paper explores potential innovative solutions to overcome these issues while anticipating the future development trends of hydropower station energy storage technology. This study provides a theoretical foundation and practical guidance for advancing strategies in renewable energy grid integration.

With the widespread application of lithium-ion batteries in electric vehicles, accurate estimation of the state of charge (SOC) of batteries is crucial for ensuring battery safety and optimal performance. However, traditional Kalman estimation methods face challenges maintaining accuracy under variable temperature conditions. To address this issue, this study proposes a SOC estimation method based on multi-innovation adaptive extended Kalman filtering (MIAEKF). This study initially performs parameter identification using battery data from experiments conducted at various temperatures. The forgetting factor recursive least squares method is employed for this purpose, providing battery parameters at different SOC stages under multiple temperature conditions. Second, a function fitting approach is used to establish a model with SOC and temperature as independent variables and battery parameters as dependent variables, describing the dynamic behavior of battery parameters. Finally, the MIAEKF algorithm is introduced, incorporating adaptivity and multi-innovation concepts from the Kalman filtering algorithm. The sliding window is introduced to replace the traditional adaptive factor for adjusting the process noise and measurement noise covariance adaptively. The mean of multi-innovations within the window is used to augment the error innovation for the posterior estimate. By selecting an appropriate window length and innovation mean coefficient, the accuracy of SOC estimation is effectively improved. Verification using experimental data shows that the SOC estimation method based on MIAEKF outperforms traditional extended Kalman filtering and adaptive extended Kalman filtering in terms of estimation accuracy and stability under the same conditions. Under multiple temperature conditions, MIAEKF can adaptively estimate SOC at different temperatures, with estimation errors within ±1%. In summary, this study effectively addresses the complexity of SOC estimation for lithium-ion batteries under variable temperature conditions by proposing the SOC estimation method based on MIAEKF.

The energy storage technology roadmap is diverse, and different types of energy storage have their application prospects. The selection of energy storage is a key issue in engineering applications. However, the selection of energy storage requires comprehensive consideration of factors such as economics and safety, making it a complex multi-objective decision-making problem. A hybrid energy storage selection evaluation system is proposed that combines the analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) with a fuzzy comprehensive analysis method. First, the judgment matrix of the evaluation system is established, and then the indicator weights undergo diagonalization and multiplication with the standardized matrix to yield the weighted judgment matrix to obtain the proximity vector. The membership assessment results of energy storage types are obtained by multiplying the weighted judgment matrix with the correlation matrix of the fuzzy comprehensive analysis method. Data in grade I indicates the energy storage system is at its optimum level, grade II follows as the next tier, and so forth in descending order. Thus, by employing TOPSIS, a more objective weight vector can be obtained, mitigating the subjectivity inherent in the AHP method. Taking seven types of energy storage, such as lithium-ion batteries, sodium-sulfur batteries, and lead-acid batteries, applied to peak load shaving, grid supply, and voltage quality improvement scenarios as examples, a comparative analysis is conducted with existing energy storage selection methodologies, highlighting the innovative nature of this evaluation framework. The effectiveness of the proposed evaluation system and selection method is verified.

Supercapacitor modules are considered as the future power source for trams owing to their capability to charge and discharge fast, along with the ability to meet high power requirements. However, during operation and the charging/discharging process, supercapacitor modules generate a substantial amount of heat, resulting in a rapid temperature. To address this issue, this study proposes a thermal management approach using microchannel liquid cooling. This method involves pumping low-temperature fluid within the microchannels of a liquid-cooled plate to cool down supercapacitor cells. By altering the boundary conditions, the working temperature of supercapacitor cells can be maintained within the appropriate range under different heat dissipation conditions. To compare the performance of the liquid-cooled plate, three models of microchannel liquid cooling plates were designed herein, and numerical simulations were conducted using ANSYS software. A new prediction model for the maximum temperature of the liquid-cooled plate was established, and the effects of boundary conditions on the performance of the new liquid-cooled plate were studied. The results indicate that the design-3 model of the liquid-cooled plate demonstrates good flow and heat dissipation performance. Increasing the mass flow rate of the cooling fluid effectively reduces the maximum temperature difference and the highest temperature of supercapacitor cells, thereby improving the uniform temperature distribution among the cells. However, as the mass flow rate of the cooling fluid increases to 0.35 kg/s, the reduction in the highest temperature of supercapacitor cells gradually decreases, indicating limited improvement in its heat dissipation performance. Increasing the flow rate also increases energy losses in the thermal management system. The temperature difference among supercapacitor cells continuously decreases when increasing the inlet temperature of the cooling fluid. However, the inlet temperature of the cooling fluid has minimal impact on the uniform temperature distribution among the cells.

Accurate identification of battery parameters is the foundation for achieving high-precision state estimation in electric vehicle battery management systems. To address the issue of insufficient accuracy when identifying changing battery parameters using the forgetting factor recursive least square (FFRLS) method, this study proposes an adaptive multilayer recursive least squares (AMLRLS) online battery parameter identification method, which updates parameters hierarchically. The AMLRLS algorithm uses the voltage error of the identified parameters of the L-1 layer as the target value for the L-th layer. It recursively separates the parameter quantities from the voltage error and aggregates them from all layers to form the identification result for a single data point, creating a MLRLS structure. To address the problem of computing up to the maximum set layer in each identification step, a layer selector is designed. It takes the voltage error from the FFRLS identification result of the first layer as input and adaptively selects the number of layers based on the magnitude of the voltage error, reducing computational load. A battery model is constructed, and simulations are conducted to verify the parameter tracking capability of AMLRLS. Results demonstrate that AMLRLS reduces parameter errors by up to 69% compared to RLS and 46.5% compared to adaptive FFRLS. In experimental validation, AMLRLS considerably reduces the root mean square error and average absolute error of voltage by 43.9% and 32.1%, respectively, under dynamic stress test (DST) conditions compared to other algorithms. Results across different currents, temperatures, and the initial state of charge conditions validate the strong applicability of AMLRLS. Finally, the computation time of various algorithms is compared. AMLRLS reduces computation time by 37.4% under DST conditions and by 28.6% under federal urban driving schedule conditions compared to scenarios without a layer selector, thus alleviating the computational burden of the battery management system.

The new energy storage project, as a measure to enhance the regulation capacity of the energy supply system and promote efficient energy utilization, is an indispensable part of the development of energy construction. However, at present, the legal development of energy storage projects is relatively slow, which to some extent restricts the development speed of new energy construction. To address the aforementioned issues, research will be conducted on legal issues related to new energy storage projects in the new era. Firstly, based on the nature of energy storage and the main types of new energy storage, we will improve the research on the classification and development status of new energy storage. Then, we will conduct in-depth exploration of energy security issues and propose corresponding solutions. We will analyze the importance of developing the new energy storage industry. Finally, to promote the legal development of new energy storage projects in the new era, we will propose two specific suggestions: improving the legal and regulatory system for new energy storage and standardizing the system of new energy storage industry.