The development status, application achievements, and directions of hydrogen fuel cell technology in China, were reviewed and analyzed, which covered aspects such as the construction of standard systems, demonstration application policies, diversification of application scenarios, and cutting-edge technologies. The results show that China has established a standard system covering hydrogen energy, complete vehicles, key components and materials. Relying on the five major demonstration city clusters, it has successfully promoted the large-scale application of the fuel cell technology. Fuel cell vehicles have achieved a significant leap in key performance indicators such as driving range and power density. The localization rate of key components such as fuel cell stacks and air compressors has exceeded 90%, and the localization process of key materials such as proton exchange membranes, carbon paper, and catalysts is accelerating. Meanwhile, application scenarios are expanding into areas such as marine, rail transportation, power generation, etc, which demonstrates technical feasibility and emission reduction benefits.In the future, key development directions for hydrogen fuel cell technology will include advanced hydrogen storage methods-such as liquified hydrogen, hydrogen swapping, and solid-state storage-alongside the advancement of low-cost, high-power, and highly durable fuel cells, as well as their deep integration with artificial intelligence; the maturity of new refueling modes such as liquified hydrogen and hydrogen swapping, the breakthrough of low-cost and long-lifetime technology routes, the in-depth integration of artificial intelligence with fuel cell technology, and the application and promotion of fuel cell passenger vehicles will become the key directions, which will drive China's hydrogen fuel cell technology towards larger-scale development.

Lithium iron phosphate (LiFePO₄) with olivine structure has the advantages of high safety, long cycle life and low cost. However, the low conductivity caused by intrinsic defects in its crystal structure limits its widespread application. Carbon coating can effectively improve the conductivity of LiFePO₄ and is the core strategy to enhance its electrochemical performance. This article reviews the research progress of carbon coating on the surface of LiFePO₄ and summarizes the methods of carbon coating, types of carbon sources and optimization strategies for carbon coating.

The hybrid power system composed of hydrogen fuel cells(PEMFC) and battery power sources involves the collaborative optimization of system design and energy management strategies, which is crucial for enhancing overall efficiency, prolonging system lifespan, and improving dynamic response performance. This paper first systematically summarizes the classification and application of the topology of the fuel-lithium hybrid power system, and analyzes the key issues of different topologies. Based on these issues, a "topology-control" logical relationship is established to provide a foundation for the optimization design of energy management strategies. The research and analysis focus on the energy management methods of the parallel and hybrid topologies: for the parallel hybrid power system with the fuel cell as the main power supply unit, the application and optimization design are studied, emphasizing the need to comprehensively optimize the working state of the fuel cell to improve the efficiency and stability of the hybrid power system. For the hybrid power system, the analysis is conducted around four key aspects: power demand prediction, energy scheduling, battery health management, and system optimization. An adaptive energy management system with multi-objective optimization is proposed. Through the combination of case studies and engineering applications, the energy economy of the hybrid power system is improved. The research shows that intelligent energy management strategies, with their online learning and adaptive characteristics, are an important research direction for achieving a performance leap in hybrid power systems in the future.

Solid oxide fuel cells(SOFC) have advantages such as high power generation efficiency, high-quality waste heat, and environmental friendliness. The commercialization of SOFC technology will provide an energy-saving and carbon-reducing pathway for achieving carbon peak and carbon neutrality goals in the future. The current domestic demonstration application status, patent layout, policy guidance, market situation, and emission advantages were reviewed. Currently, the industry is in the phase of technology importation, and there are very few demonstration projects in the industry, especially more than 100 kW SOFC systems. Local governments are gradually introducing policies to promote the development of SOFCs, additionally, R&D project policies at the national level are guiding the expansion toward large-scale commercial equipment. Overall industry investment in R&D resources is increasing, and the patent landscape is exhibiting rapid growth.

The reliability of the proton exchange membrane fuel cell (PEMFC) sealing system is crucial to its operation and commercialization, and related research has been carried out from three aspects. At the material level, the characteristics of silicone rubber, fluoroelastomer and other materials were compared, and the application value of new sealants such as UV light-curing adhesive and anaerobic adhesive was discussed. In terms of structural design, based on the interfacial stress and assembly process, the advantages and disadvantages of direct sealing, MEA/PEM wrapping and rigid frame structures were analyzed. In the durability assessment, the chemical degradation, fatigue and stress relaxation mechanisms of the sealing system under acid corrosion, heat-wetting cycle, and dynamic load are described. Future research can focus on composite material design, interface mechanics optimization and multi-scale life prediction, and provide theoretical and practical guidance for the optimization of sealing systems.

The solid electrolyte interphase (SEI) governs the safety, lifespan, and rate capability of lithium-ion batteries, yet its nanoscale thickness, heterogeneity, and dynamic evolution pose significant characterization challenges. The multi-scale characterization techniques from macroscopic (FTIR, Raman, SEM) to atomic scale (Cryo-TEM, XPS, ToF-SIMS, TMS, ssNMR) were systematically reviewed, and a comprehensive comparison was made based on spatial/chemical resolution, in-situ capability, perturbation and quantifiability. For representative systems including graphite, silicon, lithium metal, and solid-state interfaces, material-specific minimum reporting combinations (MRCs) were proposed to establish an evidence chain integrating "low-perturbation in situ monitoring, high-resolution ex situ validation, and electrochemical correlation." A "structure-evolution-function-performance" framework was introduced to quantitatively link observables (d_SEI、f_LiF、s_SEI、E_SEI) with polarization, impedance, and capacity fade. In response to the problems of in-situ limitations, cross-scale fusion and weak modeling, it is advocated to develop a sealed in-situ platform, standardized metadata and AI-driven uncertainty quantitative analysis to provide methodological support for the predictable design of battery interfaces.

As a new type of power source with low emissions and zero pollution, hydrogen fuel cells have been favored by various industries and have been applied in road transportation, shipping, aviation and other fields. However, the application of related technologies in railway transportation equipment is still in its infancy. The current application status of hydrogen energy in the rail transit field is introduced. In response to the high power and multi-condition requirements of railway transportation equipment, research has been conducted on multi-stack integration technology of hydrogen fuel cells and power source distribution technology, and vehicle-mounted verification has been carried out.

Under the background of the steady implementation of the dual carbon strategy and the global energy transformation, large-capacity lithium iron phosphate battery is widely used in battery energy storage power stations(BESS) due to its advantages such as high energy density and long life. However, the jet fire caused by thermal runaway of battery seriously restricts the further development of BESS. Delaying and preventing the group failure of battery modules under the influence of flame is a key concern. At present, there are few studies on thermal runaway combustion of large capacity batteries and related key thermal runaway variation parameters. It is clear that the variation of each parameter in the process of battery thermal runaway is the premise of putting forward the suppression scheme. Thermal runaway experiments were carried out on 100 Ah single cell and four-cell module to explore the characteristic quantities such as temperature, heat release rate, mass loss and expansion force. The results show that the single-cell battery thermal runaway jet combustion exhibits a blowout phenomenon, with a maximum heat release rate of 20.6 kW and total heat release of 4.2 MJ. During the thermal spread process of the four-cell module, the maximum heat release rate reaches 76.9 kW and total heat release reaches 33.2 MJ. The research findings provide theoretical references for fire early warning, suppression, and firefighting in energy storage power stations.

The global energy consumption is constantly increasing, and electrochemical new energy storage systems play a key role in balancing energy supply and demand. With the expansion of the scale of new energy storage systems, temperature problems caused by system operation have greatly affected the performance and safe use of the systems. Reasonable thermal management schemes and system control strategies can maintain the stability and safety of energy storage system operation. Starting from the thermal management requirements of energy storage systems, this paper analyzes the characteristics and applications of mainstream thermal management solutions, summarizes the future development trends of various solutions, and focuses on introducing temperature control strategies for energy storage systems. Finally, suggestions and prospects for future research directions in energy storage thermal management technology are provided.

With the increasing global demand for clean energy, fuel cell vehicles (FCEVs) as an emerging zero emission mode of transportation are gradually receiving attention. However, the special environmental conditions in high-altitude areas, such as low pressure, low oxygen, and low temperature, pose a severe challenge to the performance and stability of fuel cell systems. This article investigates the effects of atmospheric pressure on fuel cell stacks, systems, and auxiliary components at altitudes ranging from 0 m to 3 000 m through experimental systems, and quantitatively reveals the mechanism by which high-altitude environments affect system performance. The research results show that when the altitude rises to 3 000 m, the power of the fuel cell decreases by 12.9%, the system power decreases by 11.8%, the system efficiency in the low current range decreases by 25.2%, and the maximum increase in auxiliary system power is 209%. The performance change is mainly due to the increase in power consumption of the air compressor, with its power proportion rising from 15%-20% to 20%-25%. Based on the above conclusion, it is recommended to prioritize the high-altitude performance calibration of the air compressor when applying fuel cell systems in high-altitude areas, and reserve sufficient capacity for it in the overall development of the system to ensure stable output under high-altitude conditions.

Based on the symmetric serpentine flow field structure, three different types of baffles were arranged in the flow channels. Numerical simulations were conducted using FLUENT software to analyze the performance of proton exchange membrane fuel cells (PEMFCs) with and without baffles. The results indicate that PEMFCs with baffles exhibit higher oxygen transport capability than those without baffles, and the rectangular baffle has the highest transport efficiency. Water accumulation is observed between adjacent baffles, and the degree of accumulation is positively correlated with the cross-sectional area of the baffles. The PEMFC equipped with rectangular baffles achieve the highest power output of 0.755 W/cm², which is 25.6% higher than the PEMFC without baffles. Furthermore, the genetic algorithm was employed to optimize the dimensions of the rectangular baffles, resulting in an optimal baffle size of 0.492 mm×0.238 mm×0.396 mm. Numerical simulations were performed on the PEMFC with the optimized rectangular baffles, and comparative analyses were conducted with the pre-optimized results. The results show that the PEMFC with the optimal baffle dimensions achieve a maximum power density of 0.809 W/cm², which is a 7.2% improvement over the pre-optimized maximum power density (0.755 W/cm²).

Deeply understanding the internal physical and chemical states as well as reaction mechanisms of batteries is key to advancing lithium-ion battery technology. Optical fiber sensors, with inherent advantages of compact structure and high sensitivity, have become an effective way to solve the “black box” problem of traditional batteries and a research focus in recent years. Embedded optical fiber sensors can reveal the multi-scale and comprehensive evolution rules of batteries from 1D microscale to 3D macroscale, providing data support for refined battery modeling and management. This paper reviewed various optical fiber sensors with broad application prospects in lithium-ion batteries, summarized their practical applications from three key aspects: state of health monitoring, internal electrochemical behavior sensing, and thermal runaway early warning, and finally looked forward to their development prospects in smart batteries, aiming to clarify the technical path and application value of advanced optical fiber sensors for battery embedded monitoring.

All-solid-state lithium-sulfur batteries (ASSLSBs) effectively overcome the shuttle effect of polysulfides and lithium dendrite growth issues inherent in conventional Li-S systems by establishing a solid-solid conversion pathway, thereby significantly enhancing both safety and energy density. However, their development remains challenged by sluggish reaction kinetics, poor interfacial contact, and substantial volume changes. This review summarized recent advances in ASSLSBs, focusing on cathode material design, solid electrolyte development, interfacial engineering, and mechanistic studies. Future research directions were also outlined, including in-depth understanding of reaction mechanisms, development of novel electrolyte systems, introduction of catalytic strategies to promote conversion reactions, and advancement of practical pouch cell configurations, aiming to facilitate the transition of ASSLSBs from fundamental research to real-world applications.

With the rapid growth of energy storage systems, electric vehicles, and portable electronic devices, the safety of lithium-ion batteries has become a critical concern. As the core functional layer between the cathode and anode, the separator directly determines the lifespan, safety boundary, and reliability of the battery. Although polyolefin-based separators remain dominant due to mature processing and cost advantages, their limitations in thermal stability, mechanical strength, wettability, and chemical compatibility hinder their application under high-energy-density and complex working conditions. The main types and performance requirements of separators were reviewed, and their failure mechanisms were categorized into five modes: thermal failure, mechanical failure, electrochemical failure, functional degradation, and multi-physics coupling. In terms of analysis, a multidimensional characterization framework-covering morphology, thermal, mechanical, electrochemical, and compositional aspects was proposed, and experimental cases were used to reveal the intrinsic correlation between separator degradation and battery safety attenuation. To mitigate failure risks, modification strategies such as ceramic coating, nanofiber reinforcement, functional interfacial layers, and flame-retardant additives were highlighted. It is further emphasized that separator research is evolving from single modifications toward multifunctional synergistic optimization, requiring thin, mechanically robust, thermally stable separators with additional properties such as flame retardancy, self-healing, and intelligent sensing. Finally, perspectives on multi-physics modeling, advanced in-situ characterization, and intelligent separator development are presented to provide guidance for next-generation high-safety, high-performance batteries.

Lithium metal anode is considered to be the “holy grail” in the field of energy storage batteries due to its high specific capacity (3 860 mAh/g) and the lowest reduction potential (–3.04 V vs. standard hydrogen electrode), but the large number of dendrites generated on the surface of lithium metal anode during charge and discharge lead to decline in battery Coulombic efficiency and cycling performance. Furthermore, the uncontrollable growth of lithium dendrites easily punctures the separator, cause battery short circuit, and even battery explosion and other safety problems. Based on the main challenges of lithium metal anode, combined with the application of fluoropolymer in lithium metal batteries in recent years, this review demonstrates the important role of fluoropolymer in lithium metal batteries from the aspects of solid state electrolyte, separator modification layer, binder, artificial solid electrolyte interface (SEI) layer, composite anode, etc. Finally, the future research direction and development trend of fluoropolymer in the field of lithium metal are prospected.

In order to accurately monitor the status of hydrogen fuel cell and enhance the reliability and safety of energy supply systems, 5 predictive models were developed.Operational parameters were used as inputs for detailed simulation and comparative studies, such as anode and cathode gas pressure, temperature, etc. 3 public datasets (FC1-FC3) were tested, each containing different structural configurations, power compositions, and operating duration. Predictive results were provided for state parameters of all methods after training via Bayesian automatic parameter tuning, and correlations between method characteristics and datasets attributes were analyzed. Results indicate that classical approaches (CNN and LSTM) demonstrate certain predictive capabilities for stationary datasets. The CLA method effectively integrates spatiotemporal features, making it suitable for handling dynamic data with rich characteristics and significant fluctuations. However, for voltage sequences with stable fluctuations and periodic patterns, the CNN-LSTM approach is proved to be more effective. Transformer methods show limitations in processing stationary data. The relevant data and conclusions can be utilized to optimize predictive models for operational parameter prediction and enable intelligent condition monitoring.

Air-cooled open-cathode proton exchange membrane fuel cell requires air as both reactant gas and coolant medium, causing its cathode directly exposed to variable and potentially harsh air conditions, which is a serious challenge to performance of stack. This study conducts simulating flight experiments with air-cooled fuel cells, verifying that the stack can independently provide power for the UAV within a few hours. Subsequently, this study completes a 200 h performance test for this stack on rated conditions, and results show that the hourly average single-cell voltage drop is about 0.38 mV. The study indicates that the decline of voltage is mainly due to changes in operating parameters and environmental conditions, especially showing a significant positive correlation with the levels of major air pollutants. Meanwhile, experimental results show that even after stack voltage declines, hydrogen consumption remains at original level, indicating more energy is converted into thermal energy rather than electrical energy.

As a key component of lithium-ion batteries, the separator's performance directly affects their cycle life and safety. Polyolefin materials, such as polyethylene and polypropylene, are widely used as separators in lithium-ion batteries due to their low cost, high chemical stability, and high mechanical strength. The research progress on polyolefin separators for lithium-ion batteries was systematically reviewed. The review covered their basic properties, preparation processes, performance challenges, modification strategies, and the mechanisms by which various modification strategies enhance the safety and electrochemical performance of batteries. By combining microstructural characterization results, the multifunctional design principles underlying polyolefin separators were discussed in detail. Finally, future research directions in this field were prospected based on the current research progress.

Against the backdrop of China's "dual carbon" goals and global energy transition, the installed capacity of wind power and photovoltaic power in China has grown rapidly. However, the intermittency of renewable energy requires long-duration energy storage technologies to address, and vanadium redox flow batteries (VRFBs) have emerged as one of the key options due to their advantages such as flexible energy storage, long lifespan, and environmental friendliness. The domestic vanadium battery projects from 2011 to 2024 were statistically analyzed and the relevant policies were examined. By the end of 2024, there were a total of 189 vanadium battery projects in China, with a total installed power of 6 074 MW and a total energy storage capacity of 23 956 MWh. Operational projects were characterized by "small scale and large quantity," while the scale of projects under construction and in the planning stage had significantly increased. Vanadium battery projects have shown a year-on-year growth trend, with explosive growth in 2024. Meanwhile, there are regional differences in the development of vanadium battery projects in China: the northwest region has the largest average project scale, and the east China region has the largest number of projects. The vanadium battery industry was prospected through market development opportunities and obstacles, and future market forecasts were made for different scenarios.

Fe-based polyanion Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) is expected to become an ideal material for the cathode of sodium-ion batteries due to its abundant resources and low raw material prices. However, due to its low electronic conductivity and slow ion diffusion, a nitrogen-doped carbon-coated NFPP cathode material was constructed by gradient addition of polyvinylpyrrolidone (PVP, 0%-7%) through solid-phase ball milling. Material characterization indicates that NFPP exhibits irregular nanoparticles. The appropriate addition of PVP can optimize the crystal structure and form a porous morphology, creating a three-dimensional honeycomb-like carbon network. Electrochemical data show that NFPP-PVP5% exhibits excellent electrochemical performance. The capacity of the first charge-discharge at 0.2 C is 104.15 mAh/g. Meanwhile, it also has good cycling stability and rate performance. It can be known through calculation that NFPP-PVP5% shows the highest sodium ion diffusion coefficient. The improvement in performance is attributed to the synergistic effect of the nitrogen-doped carbon layer and the porous structure, which provides a new idea for the design of high-performance sodium-ion cathode materials.

Liquid hydrogen (LH₂) has the advantages of high transportation efficiency, low transportation cost, fast refueling speed, long drive range, etc., and has considerable advantages in storage, transportation, refueling and use. At present, China and international enterprises are gradually carrying out research on LH₂ heavy trucks, but due to the deep-cooling properties of LH₂ and the specificity of hydrogen, there are many limitations in the actual use process, the requirements of LH₂ components are more stringent. However, there is lack of inspection standards and specifications for the On-board LH₂ system, the relevant inspection and verification process is basically based on the current group standards or the ancient ISO standards, has not been formed A systematic and complete analysis and verification system. In this paper, we will analyze the Chinese and international standards for Liquid Hydrogen Fuel Cell Electric Vehicles (LHFCVs) and establish an analysis and validation system for the components of the On-board LH₂ system based on the basic performance requirements, safety, reliability, environmental adaptability, and vehicle requirements, with a view to promoting the development of the LH industry and the further development of LHFCVs.

The global carbon neutrality goals are accelerating the transition of energy systems from a "carbon-based" to a "hydrogen-based" paradigm. Hydrogen energy, particularly green hydrogen, has emerged as a critical vector for this energy transition. Spurred by international policy initiatives, green hydrogen demonstration projects have proliferated worldwide. However, most projects remain pilot-scale and face bottlenecks such as technological immaturity, high costs, and underdeveloped infrastructure. This study systematically reviews the technological advancements and policy practices in global green hydrogen demonstration projects. It examines key technological progress across the value chain, including water electrolysis technologies, hydrogen storage and transportation solutions and safety application protocols. The analysis highlights green hydrogen's potential to enable deep decarbonization in traditionally high-carbon industries within future energy systems. To overcome existing barriers, future development of the green hydrogen industry must prioritize: breakthroughs in electrolyzer components and advanced hydrogen storage/transport materials; Expansion of application scenarios to integrate green hydrogen into industrial processes, energy storage, and cross-sectoral systems; strategic scaling to establish hydrogen energy as a cornerstone for achieving carbon peaking and carbon neutrality goals.

Fast-charging capability (reaching 80% SOC within 10~15 minutes) is becoming a key performance metric for automotive lithium-ion batteries, yet the charging process and achievable efficiency are jointly constrained by lithium plating, concentration polarization, ionic-transport limitations in thick electrodes, and thermo-electrochemical coupling. This review systematically summarizes fast-charging advancements from six perspectives: mechanisms, structural design, thermal management, protocol optimization, online diagnostics, and system integration. Building on a backbone that integrates a risk map (temperature, SOC, and current density), temperature trajectory design (warm charge and fast cool), health constraints, and protocol optimization (MPC and RL), the framework couples the structural window of thick electrodes (e, t, and L) with BMS-accessible signals (dV/dt, EIS, NFRA, and ΔT/∇T), embedding safety and lifetime constraints directly into the charging-control loop. Safe and efficient fast charging can be enabled through: (i) risk maps that translate unobserved kinetic transport mismatches into hard or soft protocol constraints; (ii) reduced tortuosity, graded porosity, and rational current collector engineering to enhance D_eff and suppress polarization under high areal mass loading; (iii) warm charge and fast cool strategies that balance kinetics and side reactions in low-temperature and extreme fast-charging scenarios; (iv) individualized fast-charging control enabled by MPC, ANN-MPC, and RL under diagnostic triggers; and (v) vehicle、charger and grid coordination that sets the upper bound of minute-level energy replenishment. Finally, the article outlines a validation and admission framework based on t₈₀, ΔT, and capacity-fade rate, provides mass- production design recommendations, and highlights key future research directions for fast-charging technologies.

The oxygen reduction reaction at the cathode is one of the core reactions in fuel cells. However, factors such as the slow cathode oxygen reduction reaction and the limited mass transfer will restrict the improvement of battery performance and hinder the commercial application of proton exchange membrane fuel cells. This article reviews the effect of catalyst, carbon support and ionomer in cathode catalyst layer on the activity of oxygen reduction reaction and the optimization strategies in recent years. By regulating the morphology of Pt catalyst and developing Pt-transition metal alloys, the number of active sites can be increased and the energy barrier of oxygen reduction reaction can be reduced. Non-platinum series catalyst can significantly reduce cost while enhancing the activity of oxygen reduction reaction through their unique structures (such as core-shell, porous structure, etc.) and active sites (such as Fe-N₄). In addition, carbon support with a good pore size distribution can promote mass transfer, and modification strategies such as heteroatom doping further enhance the stability of the catalyst. The use of short side chains or highly oxygen-permeable ionomer can not only reduce the toxicity to the active site but also enhance the mass transport, further enhancing the activity of the oxygen reduction reaction. This article aims to provide guidance for the design of high-performance cathode catalyst layer.

Sc₂O₃-stabilized ZrO₂ (ScSZ) was employed as the electrolyte and screen-printed onto the flat-tube anode support to form a dense film, yielding complete solid oxide fuel cell (SOFC) of Ni-YSZ /Ni-ScSZ/ScSZ/GDC/LSCF-GDC configuration. The electrochemical performance and scale-up feasibility were systematically evaluated between 650 ℃ and 750 ℃. ScSZ exhibited an ionic conductivity of 0.146 S/cm at 900 ℃-about 2.5 times that of 8YSZ-providing a solid material basis for intermediate-temperature SOFC operation. A single cell with an active area of 60 cm² delivers a peak power of 37.8 W at 750 ℃, with polarization resistance accounting for >88% of the total cell impedance. The distribution of relaxation times (DRT) analysis reveals that oxygen adsorption-desorption is the rate-limiting step. A five-cell short stack achieves a maximum power output of 218 W at 750 ℃, comparable to single-cell performance. The full cell operates under constant-current discharge at 750℃ for 870 h with a voltage degradation rate of only 1.06% every 1 000 h, while the microstructure remains intact. The results demonstrate that ScSZ-based flat-tube SOFCs combine high power density, facile scalability, and long-term durability, offering a practical route toward kW-level, intermediate-temperature SOFC commercialization.

Thermal runaway experiments were conducted on a 304 Ah Lithium Iron Phosphate (LFP) battery under atmospheric nitrogen atmosphere. The results revealed that at 1 033 s, the vent opened, and the gas jet caused a sudden temperature rise at the vent to 100.9 ℃, while simultaneously carrying away a portion of heat, leading to a transient temperature drop on the battery side. The pressure in the sealed chamber surged by 2.8 kPa upon venting, with a maximum pressure rise rate of 1.16 kPa/s. Starting at 1 459 s, the voltage dropped from 3.43 V to 0 V over 119 s. The vent temperature peaked at 229.6 ℃ at 1 969 s after multiple eruptions, while the battery surface temperature reached its maximum of 375.3 ℃ at 1 885 s, with a peak temperature rise rate of 4.0 ℃/s (at 1 595 s). During the thermal runaway phase, the maximum pressure rise rate was 0.53 kPa/s, and gas production reached a plateau of 200.7 L at 1 983 s. The initial battery mass was 5 452 g, decreasing to 4 340 g post-experiment, with a mass loss rate of 20.40%. Gaseous products accounted for 92.7% of the lost mass, yielding a gas-to-solid ratio of 12.9. After calculating and correcting the combustion limits, the lower and upper flammability limits of the mixed gas were determined to be 6.62% and 71.08%, respectively, indicating a wide combustion range for the cabin gas. These findings provide theoretical and practical references for ensuring the safe operation of lithium-ion battery energy storage systems.

Proton exchange membrane fuel cells (PEMFCs) offer high efficiency and zero emissions, but gas leakage remains a key challenge limiting their performance and reliability. The mechanisms and influencing factors of interfacial and permeation leakage in PEMFCs have been systematically reviewed. Interfacial leakage is affected by surface roughness, contact pressure, material aging, and assembly errors, and is typically analyzed using contact mechanics and lattice Boltzmann methods. Permeation leakage involves gas dissolution and diffusion within sealing materials and PEM, influenced by material microstructure and environmental conditions. Studies indicate that sealing material properties and assembly processes are critical to system integrity. However, leakage behavior under coupled thermal-mechanical-chemical fields is still underexplored. Future work should integrate advanced testing methods, molecular simulations, and intelligent diagnostics to develop high-performance sealing materials and predictive models, thereby improving the reliability and engineering applicability of PEMFCs.

Lithium iron phosphate batteries are widely used in electrochemical energy storage and new energy vehicle applications. However, due to the flammability of the internal chemical components, these batteries can potentially lead to fire incidents under abuse conditions. This study conducted fire experiments on Lithium iron phosphate batteries at both the individual cell and module levels. The results reveal that LFP cells generate jet fires characterized by high temperatures and intense radiant heat, which readily contribute to fire spread. The combustion behavior of Lithium iron phosphate battery modules stems from the sequential thermal runaway of individual cells within the module, manifesting as intermittent jet fires. The findings provide valuable references for fire suppression strategies targeting lithium battery fires and the design of passive fire protection measures.

To investigate the mechanism of action of mixed salt systems on the performance of high-nickel/silicon-carbon batteries, lithium bis(fluorosulfonyl)imide (LiFSI) was used as the main salt, and lithium hexafluorophosphate (LiPF₆) as the auxiliary salt to inhibit aluminum foil corrosion. The physicochemical properties of electrolytes with different LiFSI/LiPF₆ ratios, as well as their effects on the rate capability and high-temperature (55 ℃) cycling stability of the batteries, were systematically studied. Aluminum foil corrosion characterization indicates that the introduction of LiPF₆ can effectively suppress aluminum foil corrosion, while cyclic voltammetry (CV) tests reveal a positive correlation between the degree of aluminum foil corrosion and LiFSI content. Electrochemical test results demonstrate that the optimized mixed salt ratio can synergistically enhance the rate capability and high-temperature cycling stability of the batteries. When the molar ratio of LiPF₆ to LiFSI is 1∶1, the battery exhibits the minimum gas evolution, the best cycling performance, and the lowest internal resistance change rate after cycling at 55 ℃, retaining 80% of its initial capacity after 370 cycles at 0.5 C/0.5 C. Precise regulation of the LiFSI/LiPF₆ ratio can significantly mitigate aluminum foil corrosion and capacity fading during high-temperature cycling, providing key experimental basis and technical reference for the electrolyte formulation optimization of high-nickel/silicon-carbon batteries.

Hydrogen fuel cells demonstrate significant application potential in the unmanned aerial vehicle (UAV) field due to their characteristics of high power density, zero emissions, and low noise. However, limitations such as restricted peak power output and insufficient dynamic response remain bottlenecks hindering their large-scale adoption. This study adopts a hybrid fuel cell-lithium battery power system architecture and develops a collaborative control strategy based on dynamic power allocation. Through constructing an experimental platform and establishing a digital twin simulation model to validate this control strategy, the results indicate that the proposed approach exhibits advantages of rapid transient response, stable power output, and high operational efficiency. Furthermore, the simulation model shows strong agreement with experimental outcomes, enabling reliable prediction of UAV endurance duration under preset loads through simulation calculations.

This study proposes a symmetric labyrinth flow channel aimed to address uneven cooling and high flow resistance in direct cooling battery thermal management systems. A CFD-based two-phase fluid-solid-thermal coupling model was developed to analyze how channel width, fillet radius, and refrigerant mass flow affect cooling performance and energy consumption. The results indicate that, in comparison with conventional serpentine channels, the proposed labyrinth design reduces the maximum cell temperature by 1.99 ℃ and the peak temperature difference between cells by 0.97 ℃under C-rates ranging from 1 C to 4 C, while simultaneously decreasing the pressure drop by 57%-78%. Optimal channel width balances heat dissipation and flow resistance. Increasing fillet radius reduces local resistance but excessive values impair boiling heat transfer. A critical mass flow saturation point exists beyond which thermal improvement diminishes while energy consumption surges. The research reveals the coupling mechanism of structural and operational parameters on thermal-energy performance, and establishes design guidelines for cold plates. These findings provide theoretical foundations and practical references for developing high-efficiency direct cooling systems.

Green recycling and resource utilization are the key to breaking the deadlock of the coming wave of decommissioned photovoltaic (PV) modules. This paper systematically reviews the management policies, mainstream technologies and full-life-cycle environmental impacts of decommissioned PV modules. Currently, the recycling and resource utilization of decommissioned PV modules still face multiple challenges in the coordination of technology, economy and policy: mainstream technologies such as pyrolysis and hydrometallurgy still need breakthroughs in efficient removal of ethylene-vinyl acetate copolymer (EVA) encapsulation film and low-carbon recovery of valuable metals. Major economies such as China, the European Union and the United States have initially established an extended producer responsibility framework. Under this framework, resource utilization pathways are showing a diversified trend, expanding from traditional material recycling to high value-added directions such as conversion into building materials and photocatalysts, showing significant potential. However, technical implementation and policy coordination still need to be strengthened. Life cycle assessment confirms that recycling can effectively reduce full-cycle carbon emissions and environmental toxicity, but secondary pollution control in the process needs urgent optimization. Finally, this paper prospects the future of resource recovery, policy management and industrial application of decommissioned PV modules.

The flow field of solid oxide fuel cells significantly influences their performance, making optimization design crucial. Based on computational fluid dynamics, a five-inlet serpentine flow field was constructed and compared with typical Z-shaped flow fields, serpentine flow fields, and the previously developed three-inlet serpentine flow field. The study revealed that the five-inlet serpentine flow field provides a more uniform gas distribution and a more even electrolyte current density distribution, effectively reducing polarization losses caused by concentration gradients. The design featuring multiple inlets and fewer bends minimizes the impact of excessive gas accumulation due to high internal flow rates while enhancing the thermal management capabilities of the cell. Under conditions where the total fuel velocity is 7.2 m/s and the total air velocity is 18 m/s, the maximum output power of the five-inlet serpentine flow field increased by 22.6%, 13.94%, and 12.95% compared with those of Z-shaped, single-inlet serpentine, and three-inlet serpentine flow fields respectively.

In response to the challenges associated with uneven temperature distribution in square lithium ion batteries, this paper proposes a parallel serpentine liquid cooling channel structure and evaluates its heat dissipation performance in comparison with traditional serpentine channel structures and conventional parallel channel structures. By analyzing the effects of three factors—namely, the mass flow rate of the coolant at the inlet, the inlet temperature, and the thickness of the liquid cooling plate—on the heat dissipation performance of the parallel serpentine channel structure, and employing orthogonal experiments and range analysis, this study ranks the significance of these three influencing factors to ascertain the optimal parameter combination. The research findings indicate that the heat dissipation performance of the optimized parallel serpentine channel structure is significantly enhanced, with the maximum temperature difference of the battery pack reduced by 63.9% and the pressure drop decreased by 7.7% in comparison to the original model. This study serves as a reference for the development of thermal management systems that offer improved heat dissipation performance and reduced energy consumption.

Lithium-ion batteries (LIBs) represent the most widely applied electrochemical energy storage technology currently. Lithium-ion battery binders serve to directly adhere active materials and conductive agents to metal current collectors, while ensuring the uniformity of active materials during slurry preparation. Additionally, they assist in forming a stable solid electrolyte interface (SEI) layer on the electrode surface. Furthermore, the design of conductive binder networks can mitigate issues such as volume expansion-induced capacity fade during the charge-discharge processes of lithium-ion batteries. Carboxymethyl cellulose (CMC), as an electrode binder, has been widely commercially applied. The structural properties and applications of CMC were briefly summarized, the bonding mechanism of the battery binder was deeply analyzed, and the mechanism of action of the modification methods of CMC in improving the performance of lithium-ion batteries was systematically expounded. Finally, the development of CMC binders was prospected.

Low-temperature start-up performance is one of the key technical indicators of proton exchange membrane fuel cell stack. In order to study the influence of low-temperature start-up on membrane electrode, this paper analyzes the low-temperature start-up method of fuel cell stack. Through shutdown purge and ' intermittent start-stop small cycle+reducing air metering ratio' method, the 60 kW fuel cell stack is realized at –30 ℃ without auxiliary low-temperature start-up. Finally, the influence of the low temperature start-up process on the membrane electrode is studied by disassembling and characterizing the key components of the membrane electrode after multiple start-ups.

To investigate the safety of an automotive power battery pack under bottom impact, a finite element model of the battery pack bottom impact was established. The model was validated against simulation tests conducted according to the latest national standard requirements for battery pack bottom impact testing. Test results show that the energy absorption ratio of the battery pack's protective bottom plate is as high as 64.37%, playing a decisive role in the battery's protection performance. Furthermore, factors including impact velocity, impact angle, impactor geometry parameters, bottom plate thickness, bottom plate material, and bottom plate structure were considered. Using the orthogonal test method, 27 sets of battery pack bottom impact test conditions were designed. The influence of various factors on the penetration amount of the battery pack base plate and the penetration amount of individual battery cells was analyzed. The results show that among the external factors, the ones with the most significant influence are the impact speed, the impact angle, and the radius of the cone tip. The penetration amount of the base plate and the penetration amount of individual battery cells increase with the increase of the impact speed and the impact angle, and decrease with the reduction of the radius of the cone tip. However, the influence of the cone apex angle on the penetration amount of the base plate and the penetration amount of individual battery cells is relatively small. Among the internal factors, the ones with more significant influence are the thickness of the base plate and the structure of the base plate. Among them, the thickness of the base plate only has a significant influence on the penetration amount of the base plate, while it has a relatively weak influence on the penetration amount of individual battery cells. The structure of the base plate has a significant impact on the penetration amount of the base plate, and the order of the protective effect from best to worst is circular core structure, BRAS sandwich structure, and reinforcement structure.

The practical deployment of lithium-ion batteries is hindered by sluggish ion-transport kinetics in liquid electrolytes and insufficient stability across wide operating temperature ranges. To address the fast-charging requirements of lithium iron phosphate (LFP) power batteries, we designed a novel fast-charging electrolyte based on acetonitrile (AN), a solvent with intrinsically high ionic conductivity. By optimizing the lithium salt formulation and introducing fluorinated and high-temperature additives, the electrolyte demonstrates markedly enhanced fast-charging capability at both ambient and elevated temperatures. Compared with commercial ethyl acetate (EA)-based electrolytes, the developed AN-based formulation exhibits a two-fold increase in ionic conductivity at 25 ℃ and retains a discharge specific capacity of 36 mAh/g after 600 cycles under 4 C fast-charging conditions. This study offers a promising commercial pathway for fast-charging electrolytes tailored for high-energy-density power batteries operating across a broad temperature spectrum.

Durability is a key technical problem restricting the commercialization of proton exchange membrane fuel cell (PEMFC). In view of the core limitation of the current accelerated stress test (AST) for durability-its difficulty in accurately reflecting the multi-factor synergistic degradation of fuel cells under on-board operating conditions, as well as the fact that in existing studies, there are many types of operating conditions for the overall degradation of single cells, which differ greatly from on-board operating conditions, this study for the first time used the operating condition curve based on the China Automotive Test Cycle to operate a fuel cell single cell under this cycle. Combined with performance tests, the performance degradation rate of the single cell was characterized. The results show that after operating under this China Automotive Test Cycle for a total of 650 h, the performance degradation amplitude at the rated point (1.2 A/cm²) reaches 20.94%, decay rate is 0.12 mV/h .