Lithium-ion batteries (LIBs) dominate the consumer electronics and electric vehicle markets duo to their high energy density and mature industrial infrastructure. Meanwhile, lithium metal batteries (LMBs) are regarded as the pivotal direction for the next-generation high-energy storage devices duo to the superior theoretical capacity of lithium metal anodes. However, LIB cathode materials suffer from the structural distortions and interfacial side reactions during deep lithium (de)intercalation, leading to the capacity degradation. LMBs face the challenges such as poor lithium affinity, dendritic growth, and limited Li⁺ transport kinetics, hindering their practical implementation. In order to address these issues, the recent optimization strategies were reviewed. The pre-embedding of the disordered structures in lithium-rich layered oxide cathodes was conducted to reconfigure oxygen frameworks and activate lattice oxygen, achieving high capacity and cycling stability. A gradient framework was constructed in LMBs anodes to achieve the dendrite-free stepwise lithium deposition. The future development trends and application prospects of lithium batteries were prospected.

Lithium ion batteries (LIB) are widely used for mobile energy storage due to their high energy density and long cycle life. However, the limited resources of lithium severely limit its application in large-scale energy storage. In recent years, sodium ion batteries (SIB) have become a promising alternative to LIB due to their low cost and high safety. Hard carbon, with its low redox potential, stable structure, large layer spacing and relatively low cost, is widely used as an anode material for SIB. However, the poor multiplicative performance and low initial Coulomb efficiency of hard carbon anode limit the performance of SIB. This paper reviews the research progress of hard carbon anode for sodium ion batteries, including the mechanism of sodium storage in hard carbon, selection of precursors and the effect of preparation process on the performance of hard carbon.

In recent years, with the rapid development of the new energy industry, the high-nickel ternary cathode materials (NCM/NCA) have become widely used in the lithium battery industry due to their high specific capacity and energy density. Increasing nickel content can enhance the reversible capacity and energy density, but introduce some challenges, such as cation mixing (Li⁺ and Ni²⁺), lattice oxygen release, electrolyte decomposition, and decreased thermal stability. These factors contribute to the performance degradation and safety risks. In order to address these issues, recent research has focused on the surface coating, micro/nanostructure design, and element doping to improve the battery performance and safety by protecting particle surfaces or optimizing crystal structures and particle morphology. These improvement strategies for high nickel cathode materials were summarized and compared.

Establishing models to evaluate the performance and lifespan of lithium ion batteries under various operating conditions could significantly shorten the design and validation cycle and enable highly reliable, full-lifecycle operational maintenance of batteries. Recent studies have highlighted that preloading forces applied during battery operation have a notable impact on its performance and lifespan. Consequently, integrating electrochemical, thermal, and mechanical fields into coupled modeling frameworks has become a research focal point. This review examines the current state of electrochemical-thermal-mechanical coupling models, detailing methodologies for electrochemical-thermal, electrochemical-thermal-mechanical performance models, as well as aging models. The aim is to provide a comprehensive overview of recent advancements while identifying critical technical challenges that need to be addressed for future model development.

Lithium ion batteries are prone to capacity degradation during long-term operation, with varying degrees of degradation and different underlying mechanisms under different operating conditions. Through the study of cycle failure of lithium ion batteries under different conditions, the mechanisms are investigated in order to provide insights for optimizing battery design to enhance the safety and durability of lithium ion battery use. This article summarizes the situation of cycle capacity degradation and failure mechanisms under different temperatures, pressures, charge-discharge rates, overcharging and overdischarging, as well as State of Charge (SOC) cycling ranges. Relevant strategies are proposed to improve the performance of lithium ion batteries and ensure their safe and stable operation.

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.

Lifespan and safety are the core challenges for the large-scale application of lithium-ion batteries, and lithium plating is an important cause of safety issues such as accelerated battery life decay and thermal runaway. Therefore, lithium plating detection has always been a research focus in the field of batteries. Electrochemical impedance spectroscopy(EIS) is a non-destructive in-situ electrochemical analysis method that can reveal the electrode kinetics of different time scales inside the battery, including charge transfer reactions, interface evolution, and mass transfer processes that are affected by lithium plating. Therefore, it can be used as a lithium plating detection method. The lithium plating detection methods were summarized based on EIS in recent years, including: static EIS method, dynamic EIS method, and current interruption method. The principles, advantages, and disadvantages of the three methods were reviewed, and the application prospects of the above methods were 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.

Excessive current density and high roughness of electrode surface during charging and discharging of lithium ion batteries will lead to uneven lithium deposition. The growth of lithium dendrites will puncture the SEI film ( Solid Electrolyte Interface film ) formed by the reaction of the anode material with the electrolyte. Lead to direct contact between lithium dendrites and electrolyte. Part of the dendritic fracture generates lithium metal particles. Part of the electrolyte and the continuous side reaction to produce lithium compounds, that is, dead lithium. It has a great influence on the safety and performance of lithium batteries. At present, the problems such as lithium dendrites and dead lithium in the SEI film are still not effectively solved. In this paper, the formation mechanism of SEI film, lithium dendrites and dead lithium in lithium batteries and some suppression methods proposed at this stage are reviewed. The key problems and future development directions are discussed. It provides a certain theoretical basis and practical guidance for the field of battery research.

With the popularization of electric vehicles and the gradual increase in ownership, the market demand for fast-charging batteries is becoming more urgent. In recent years, the technical development of fast-charging lithium-ion batteries is very significant. The charging rate has gradually transitioned from 2 C to 4 C, and developed towards 6 C or even 8 C. In order to address the challenges brought by super-fast charging, the role and improvement directions of electrolyte in fast-charging batteries were analyzed, focusing on three aspects: solvents, electrolytes and additives. The wettability issue of the electrolyte to electrode sheets during fast charging was analyzed. The potential of the secondary injection process in reducing impedance and improving battery cycle performance was explored. It can help the academic community and industry understand the impacts of electrolytes in fast charging, laying a foundation for the design and process optimization of electrolytes.

With the large-scale application of lithium-ion batteries for energy storage, the gas diffusion behavior during thermal runaway(TR) and its early detection have received extensive attention. Thermal runaway experiments were conducted triggered by external heating on 280 Ah LiFePO₄ batteries, the gas compositions released during the thermal runaway process were analysed, and the characteristics of thermal runaway under different states of charge(SOC) were explored. The experimental results show that under high SOC conditions, the thermal runaway triggering time of the battery is short, the surface temperature rise rate is higher, and the proportion of H₂ in the thermal runaway gases released from 100% SOC batteries is as high as 44.84%. In contrast, the thermal runaway process of low SOC batteries is more moderate and mainly releases CO₂(78.41% of CO₂ in the thermal runaway release gas of 0% SOC batteries). In addition, the diffusion behavior of gases during the thermal runaway process of lithium iron phosphate batteries in energy storage systems was simulated using ANSYS Fluent software. The simulation results show that there are significant differences in the gas diffusion paths under different SOC conditions: under high SOC, the gas mainly rises rapidly along the vertical direction and diffuses in the top region, whereas under low SOC, the gas first accumulates at the bottom and then gradually diffuses to the whole space. The influence of SOC on the thermal runaway characteristics and gas diffusion behavior of lithium iron phosphate batteries was revealed, which provided an important theoretical reference for the safe and optimal design of lithium-ion energy storage systems.

This work conducts the charge/discharge cycling tests of graphite||LiFePO₄ pouch batteries at temperatures of 25, 45, 60, 70, and 80 °C to calculate the battery cycling capacity degradation rate. Arrhenius formula is used to calculate the activation energy of LiFePO₄ batteries at different temperatures. Differential capacity vs. voltage (dQ/dV) curves is used for capacity loss analysis. Combined with characterization data such as SEM, ICP, XRD, etc., the results show that when the temperature exceeds 60 °C for cycling test, the growth of the SEI layer at graphite electrode interface accelerates, the microstructure of positive and negative electrode active materials ruptures, and the dissolution/precipitation of transition metal ions aggravates, leading to deterioration of battery performance and accelerated capacity degradation.

The free-piston Stirling generator is composed of a Stirling engine and a linear motor. It describes a single-gap motional magnetic structure linear motor. During operation, the electromotor components oscillate back and forth under the drive of the piston. During operation, the motor's moving component oscillates under the drive of the piston. Finite element simulation analysis of the electromagnetic performance of the linear motor was conducted. By comprehensively evaluating parameters such as no-load output characteristics, and load output characteristics, the magnetic circuit structure parameters were determined. Through the analysis of the dynamic characteristics of the linear motor, the resonant operating characteristics of the linear motor were clarified. Based on the optimized structural parameters, a prototype was designed and manufactured for experimental testing, verifying the motor's operational performance.

In order to optimize the thermal performance of the battery thermal management system, three types of runner structures were designed based on the new roll-bond liquid cooling plate. Experiments and CFD simulations were used to compare the heat transfer characteristics, flow characteristics and resistance characteristics of the three runner structures at different inlet mass flow rates and temperatures of the liquid cooling plate, and the most suitable runner form was selected and further optimized. The results show that the liquid-cooled plate has significantly improved the temperature uniformity, and compared with the original runner structure liquid-cooled plate, the temperature difference in the top section of the module and the maximum temperature difference are reduced by 0.733 1 and 0.563 4 K, respectively, and the maximum temperature of the cell and the flow resistance are only increased by 0.15 K and 2.206 kPa.

Li₂NiO₂ offers the advantage of a high first-cycle charge capacity, and its delithiation voltage is well-matcedh with most cathode materials, making it one of the research hotspots in the field of cathode pre-lithiation. However, Li₂NiO₂ is highly susceptible to degradation upon exposure to air due to reactions with H₂O and CO₂, which results in the formation of inactive byproducts and loss of its pre-lithiation functionality. The low air stability poses significant challenges in terms of storage and during manufacturing processes such as electrode coating and drying. In this work, we for the first time employed a novel dopamine dry-mixing technique followed by high-temperature calcination to prepare a carbon-coated Li₂NiO₂ pre-lithiation agent. The resulting carbon coating effectively inhibits air-induced corrosion, substantially reducing the formation of byproducts such as Li₂CO₃ and LiOH. After 24 hours of air exposure, the first-cycle charge capacity attenuation of Li₂NiO₂ was dramatically reduced from 51.9% to 14.2%. Furthermore, when the carbon-coated Li₂NiO₂ pre-lithiation agent was incorporated into NCM9055 cathodes, the full cell exhibits a 14.9% increase in first-cycle discharge capacity and an 11.5% improvement in capacity retention after 150 cycles.

The positive electrode, negative electrode and the separator are stacked into a jelly roll by stacking process. The high pressure real density of the positive electrode causes the irrecoverable bending deformation of the positive electrode with the direction of the roll. Due to the requirements of high energy density and high power, the current collector is getting thinner and thinner, and the area of the cutting tab is getting larger and larger, and the mainstream 6μm Cu current collector is extremely easy to fold in the process, resulting in short circuit. In this paper, the bending degree of the positive electrode is improved by using the anti-correction device of the positive electrode to achieve the purpose of flat surface of the positive electrode. The negative electrode adopts the anti-bending mechanism of the tab to press the special shape pattern on the surface of the tab to increase the strength of the foil and prevent the tab from bending and sagging. The above two measurements can effectively improve the electrode status and reduce the occurrence of defects in the production process.

In order to solve the problem of appearance deformation in the production process of the pouch cell, the possible deformation mechanism in the whole process of the cell production was analyzed, and then a series of solutions were put forward, such as reducing the capacitance current, pressurizing the capacitance and full electrochemical formation. The experimental results show that the heating and pressurization can effectively optimize the bad appearance, reduce the stack thickness of the cell, and improve the interface to enhance the cycle performance of the cell. However, the aging stage after full electrochemical process will consume active substances, resulting in a decrease in cell capacity. Therefore, the loss of cell capacity can be reduced by further adjusting and reducing the charge state of the cell after the cell is fully electrolyzed to improve its appearance, so as to achieve the best improvement effect.

Anode-free lithium metal battery has become an academic hotspot due to its high theoretical capacity, energy density and low cost. However, due to the lithium-sparse property of copper foil and the high activity of lithium metal, the lithium deposition/stripping is not uniform, resulting in many problems such as lithium dendrites and excessive lithium consumption, which limits the practical application. In this paper, the advantages, challenges and solutions of anode-free lithium metal batteries were comprehensively reviewed. Four improvement strategies were discussed in detail, including modifying the current collector, constructing a stable solid electrolyte interface(SEI) film, introducing lithium supplementation technology and optimizing the electrolyte. The mechanism of the negative side affecting the deposition / stripping of lithium metal, the advantages of the positive side additional lithium source and the influence of the electrolyte on the reversibility of the anode-free lithium metal battery were discussed. The advantages and disadvantages of the four strategies and the future development direction were summarized.

In recent years, the recycling and treatment of waste lithium ion batteries and lithium iron phosphate (LFP) cathode materials in the field of new energy have attracted widespread attention. In addition to reducing the pollution of harmful components in waste batteries to the environment, the regeneration of battery materials is also crucial for resource utilization and economic benefits. This article reviews the research progress of LFP direct regeneration methods such as solid-phase method, hydrothermal method, eutectic method, and electrochemical regeneration method. At the same time, it introduces a groundbreaking new LFP regeneration technology. Finally, this article briefly introduces the commercialization process of direct recycling of waste lithium ion battery materials, discusses the advantages and disadvantages of LFP direct regeneration method, and some challenges encountered in the current regeneration process. It also looks forward to the future development of this field, laying a good foundation for further realizing the industrial production of LFP battery recycling.

Artificial graphite with different physical indexes (such as oil absorption value, particle size, specific surface area, tap density) was selected, and the slurry was prepared by conventional wet and dry batching technology of lithium ion battery, and the negative electrode sheet was obtained by coating and drying. Then the slurry and the negative electrode were tested for viscosity, fineness, sieving time, rheology, compaction, rebound and other processing properties. The results show that the larger the oil absorption value, the wider the particle size distribution, the larger the specific surface area, the smaller the tapping, and the worse the rheological properties of the slurry; the wet batching process is easier to obtain a slurry with a stable dispersion network, and the sieving time of the qualified slurry prepared by the dry batching process is short, but the dispersive mesh of the slurry will be destroyed under high shearing force, and the slurry will precipitate. The research results have important guiding significance for the improvement of the manufacturing process of artificial graphite materials and the manufacturing process of lithium-ion batteries.

This paper investigated the degradation mechanism of a 280 Ah lithium iron phosphate/graphite battery under high-temperature charge/discharge cycling conditions at 45 ℃. The differential voltage curve (dQ/dV) during cycling was analyzed to identify the sources of capacity loss. By disassembling batteries with 100%, 90%, and 60% state-of-health (SOH) lifetimes, the changes in the morphology, structure, and specific capacity of both the positive and negative electrodes were systematically examined. The comprehensive analysis reveals that the reduction in battery capacity is primarily due to the damage to the graphite structure and the loss of active lithium. The decomposition, reformation, and thickening of the solid electrolyte interphase (SEI) layer are the main mechanisms responsible for the depletion of active lithium.

To address the failure issue of lithium iron phosphate batteries caused by overcharging, this study compares the overcharging curve characteristics of various batches of lithium iron phosphate batteries. Additionally, by utilizing multiple characterization analysis methods, we investigate the failure phenomenon and mechanism of battery caused by overcharging. When the batch B battery was overcharged to 1 070 s, the battery short circuited and caused thermal runaway. The disassembly photos of the R corner of the anode revealed a grayish-black morphology, indicating a severe Fe precipitation reaction. The Fe element originates from rod-shaped impurities containing 33.22% Fe in the cathode. The precipitated Fe metal uniformly fills the base film layer of the separator, causing short circuit during the overcharge of the battery. Short-circuit discharge of the battery can cause Li⁺ to re-intercalate into the positive electrode, resulting in an initial discharge capacity of only 92.21 mAh/g for the cathode. This finding offers a theoretical basis for the design and overcharge tolerance performance improvement of 300 Ah high-capacity and high-safety lithium iron phosphate batteries.

The electrode materials constrain the technological advancement of thermal batteries used in advanced weaponry. High-quality electrode materials need to possess high thermal stability, high electronic conductivity, low solubility in molten salt electrolytes, fast discharge kinetics, and low cost. This paper discussed the performance deficiencies of current thermal battery electrode materials from the perspectives of nanoscale structural design, surface modification, and element doping, systematically reviewing the current development status of electrode materials to provide valuable reference directions for the optimization and application development of high specific energy thermal battery electrode materials.

Long-term Remaining Useful Life (RUL) prediction from limited early-aging data is challenging. A hybrid LOESS-Transformer (L-T) model was proposed to address this issue. This model combined Locally Estimated Scatterplot Smoothing (LOESS) and the Transformer. First, the LOESS algorithm preprocessed the capacity degradation data. It effectively filtered noise and captured the core degradation trend. Then, the Transformer model was used for RUL prediction, leveraging its ability to capture long-sequence dependencies. Results were compared against baseline models like LSTM and CNN-LSTM, using only the first 30% of data. The proposed model showed significantly improved accuracy and robustness. For the NASA B0005 battery, the L-T model achieved an MAE of 0.015 7, an RMSE of 0.021 6, and an RUL relative error of 5.77%. For the CALCE CS2_38 battery, performance was outstanding. The R² reached 0.982 2, and the RUL relative error was only 0.13%. This method provides an effective new approach for battery RUL prediction under limited information.

In response to the strength design challenge of the shell structure caused by the expansion in the thickness direction during group discharge of lithium fluorinated carbon flexible packaging batteries, a 22 Ah lithium fluorinated carbon flexible packaging battery was taken as the research object. The expansion force changes in the thickness direction of different numbers of flexible packaging batteries during discharge were tested through pressure sensors. The relationship between the number of batteries and the expansion force was established through formula derivation. Based on this relationship, the shell of 16 parallel battery cells was designed and its stress situation was simulated and analyzed using ANSYS Workbench software. The results show that the simulation results are basically consistent with the actual shell expansion deformation results after discharge, verifying the accuracy of this method. The establishment of this method provides important support for the safety margin design of battery cell casing structure.

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.

All-solid-state lithium-sulfur batteries (ASSLSBs) with high theoretical specific capacity (1 672 mAh/g) are one of the most promising next-generation energy storage technologies. Constructing a good ion/electron channel is the key to achieve high-performance ASSLSBs. Cathodes with sulfur content up to 50% were prepared by a high-energy two-step ball milling method using Li₇P₃S₁₁ (LPS) as the electrolyte. And the effects of the ion-to-electron conductive additives ratio, ball milling parameters and carbon materials on the electrochemical performance of the cathode were investigated at high sulfur loading (6 mg/cm²). The results demonstrate that when the ratio of LPS to acetylene black (AB) in the composite cathode is 3:2, it is conducive to the construction of good ion/electron transport channels and excellent electrochemical performance; on this basis, the ball to material ratio of the ball milling compounding process was further optimized, and it is found that the cathode S₅₀-LPS₃₀-AB₂₀ prepared at a ball to material ratio of 70:1 exhibits the optimal electrochemical performance, with an initial discharge specific capacity of 1 312 mAh/g, good rate capability and cycle stability.

The development and application of space solar array were reviewed, the technical characteristics and engineering application of different types of solar array were summarized, including rigid solar array, semi-rigid solar array, and flexible solar array. The traditional rigid solar cell array and semi-rigid solar array could not meet the needs of future space missions limited to its low power/mass ratio and power/volume ratio. The flexible solar cell array with flexible substrate had specific power/mass ratio of more than 200 W/kg and power/volume ratio up to 40 kW/m³, which were greatly improved compared with the rigid solar cell array. Therefore, flexible solar array becomes an important development direction in the future. Based on the future application demand and the technology status in China and abroad, the key technologies of all flexible solar array, such as flexible electrical connection, flexible component packaging, high-performance extension mechanism, were analyzed, and feasible technical solutions were put forward, which could provide reference for the development and application of all flexible solar array.

Appropriate flow field can improve fuel cell performance and fuel utilization rate. Simulation can be used as an important tool for flow field plate design and optimization. Through the Fluent software, this paper carried out the numerical simulation of the 509 cm² large area fuel cell at two different operating pressures of 101 kPa and 200 kPa. Under different operating pressures, the fuel concentration shows a decreasing trend along the flow direction, and as the operating pressure increases, the gas distribution uniformity of each component is higher, and the output current density of the fuel cell is higher. The polarization curve of fuel cell simulation is in good agreement with the experimental results, so the structure of proton exchange membrane fuel cell with large area bipolar plate in this paper has a certain reference value in the practical engineering application of fuel cell.

For secondary battery electrode materials, high-entropy design can achieve better structural stability, bulk electronic conductivity, and ion diffusion rate. The high-entropy modified electrode materials in lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), potassium-ion batteries (PIBs), and aqueous zinc-ion batteries (ZIBs) in recent years were reviewed. The constitutive relationship between superior electrochemical performance and high-entropy structure was analyzed. The current status of the development of high-entropy electrode materials and the challenges was systematically summarized. This paper also gave the insights into the design of high-entropy materials to provide a reference for the industrialization of high-entropy electrode materials for secondary batteries. The reference for promoting the industrialization of high-entropy electrode materials for secondary batteries was provided.

Higher safety performance and extremely fast charging capabilities of lithium-ion battery are demanded along with the rapid upgrading of electrical products and the expansion of the application field. During the fast charging process, lithium plating on the graphite anode would lead to capacity fading, higher safety issues and shorter service life. The mechanisms of lithium plating were explained. Three distribution states of lithium plating were listed and the forming processes were analyzed. The factors leading to lithium plating on anode were discussed, including cell N/P value, charging temperature, charging rate, overcharge and Overhang design. Some solutions for prohibiting lithium plating were proposed. The future research directions on lithium plating were prospected.

Using density functional theory based on first-principles, theoretical calculations were conducted on the modification of lithium manganese phosphate (LiMnPO₄) materials. Compared with LiFePO₄, LiMnPO₄ offers a higher voltage with a comparable specific capacity, but it suffers from low electrical conductivity and lithium-ion diffusion coefficients, resulting in poor electrochemical performance. Therefore, this paper aimed to enhance the electrochemical performance of LiMnPO₄ materials through doping modification, achieving a balance between high energy density and high safety. The evaluation indicators include volume change, electronic conductivity, voltage, lithium-ion diffusion, and thermodynamic stability. Five elements, namely Fe, Co, Ni, Nb, and Ti, were selected for doping modification. After doping with heterologous elements, the band gap of the materials decreased, leading to improved electronic conductivity. Ni and Co doping increased the voltage of Li-MnPO₄ but compromised the material's safety. According to the radar chart of the five evaluation indicators, Fe doping exhibits the best overall performance. Based on lithium iron manganese phosphate, Ni and Co were selected for dual-element doping modification as the second dopant. Compared with Ni doping, Co doping further improves the electronic conductivity of the material.

Low temperature thermal energy (<100 ℃) widely exists in energy systems and nature. Utilizing thermal energy at low temperatures is crucial for lowering energy costs and carbon emissions. Thermoelectric generator (TEG) without moving part can directly convert heat into electricity through the Seebeck effect, which has great development prospects. The key strategies for raising TEG system is optimized structure of thermoelectric leg, heat exchange, and operation parameters. Previous studies have not investigated the optimal structural characteristics of the thermoelectric leg and heat exchanger for utilizing low-temperature thermal energy. In this paper, a numerical model of TEG system was established. With consideration of system pressure drop and pump consumption, the effects of thermoelectric leg and heat exchange structure on net output power and system output efficiency for different operating parameters were studied. The results show that the short and wide thermoelectric leg is conducive to net output power for heat source below 35~100 ℃. For heat source temperature 60~100 ℃, thin and high thermoelectric leg exhibits better system output efficiency, and thick and high thermoelectric leg present better net output power and system efficiency. When hot source temperature is 35 ℃, short and wide thermoelectric leg exhibits higher system efficiency, thin and high fin present highest net output power and system efficiency.

LiFePO₄ batteries are widely used in new energy vehicles and new energy storage fields due to their high safety and low cost, but their applications are limited by the greatly reduced performance in cold winters, high altitude areas, aviation base stations, and other low-temperature environments. This review focused on the low-temperature performance degradation mechanism of LiFePO₄ batteries, and summarized the recent domestic and international research developments of LiFePO₄ batteries from three aspects: electrode materials modification, electrolyte optimization, and low-temperature heating technology. Finally, a new insight was put forward for improving the low-temperature performance of LiFePO₄ batteries and the future development direction was indicated.

To investigate the comprehensive thermal effect of ambient temperature variation and radiation on energy storage lithium batteries within a container, a 45-foot high-cabinet container from an energy storage power station in Baotou (a severe cold region) was selected as the prototype for analyzing heat infiltration. The study also analyzed the influence of winter and summer ambient conditions on the thermal characteristics of lithium batteries under different discharge rates in both operating and non-operating states. The results show that during the operating state of lithium batteries, the maximum temperature gradually converges with the increase of discharge rate. Under winter conditions, the maximum influence of temperature rise reaches 20.93%, while in summer it reaches 8.20%. In the all-day non-operating state, the relationship between ambient influence duration and lithium battery temperature change is linear: after 24 hours, the temperature decreases by 43.6% relative to the initial temperature in winter, and increases by 11.4% in summer. The results of the study can help predict the temperature change of lithium battery without thermal management, and provide a reference for the design of battery thermal management technology.

A SOH estimation method for lithium-ion batteries combining the physical life model and data-driven model was proposed. The physical constraint model was embeded in the neural network (NN) by combining the actual experimental data with the physical constraints, and the effective fusion of the physical model and data-driven model was realized by means of the fusion loss function, improving the interpretability and accuracy of the model. The simulation results show that in terms of the prediction accuracy, the proposed fusion model is significantly better than the data-driven method based on neural network, the physical model method and the equivalent circuit model (ECM) method based on the second-order Thevenin.

The process of the event that one of two circular solar arrays fails to deploy after Cygnus-18 cargo spacecraft of Northrop Grumman Company launched in orbit was sorted out. Combined with the total scheme of Cygnus-18 cargo spacecraft and the evolution of the solar array design scheme for power system, the design scheme of the spacecraft UltraFlex solar array was analyzed. Combined with the technology detail of the UltraFlex solar arrays for Orion spacecraft and the deploy failure of circular solar arrays for LUCY asteroid probe, the failure reason was analyzed and studied. Some suggestions for the development of circular flexible solar array for spacecraft in China were put forward. The progress of the event will be continually tracked, and the further in-depth research will be carried out.

In the construction of solid-state lithium battery systems with high specific energy, high safety and long life, it is especially critical to solve the interfacial contact and compatibility problems between the solid-state electrolyte and electrodes. Under the conditions of in-situ polymerization integrated preparation, the modification of the electrode/electrolyte interface of the solid-state electrolyte membrane can improve the interfacial compatibility between the solid-state electrolyte and electrode. In-situ polymerization strategy effectively reduces the interfacial impedance, enhances the interfacial contact for improving Li⁺ transport performance, and simplifies the scalable preparation process. Based on the polymer types, the progress, prospects, and challenges of solvent-free in-situ polymer electrolytes triggered by UV light or heat for lithium metal solid-state batteries were reviewed.

The research status of wireless power transfer technology and fuel cell technology at home and abroad was investigated. Under the overall planning framework of the fourth phase of the lunar exploration project, the mission requirements of the basic energy system of the lunar research station were analyzed and studied. The composition of the basic energy system of the lunar scientific research station was put forward, the function, working principle and working mode of the energy system were analyzed, and the main technical indexes were given. Preliminary analysis of the key technologies involved in the energy system were given, including integrated the thermoelectric energy utilization technology, highly reliable and efficient control technology of renewable fuel cells, miniaturized and efficient far-field laser wireless power transfer technology, kW level near-field wireless power transfer technology and stability modeling and analysis technology of complex multi-source energy system. Based on the scheme design and key technology analysis, the follow-up work was discussed, and the next work suggestions were given.

Lithium-sulfur batteries have theoretically high specific energy density (2 600 Wh/kg) and specific capacity (1 675 mAh/g), which are considered as one of the most potential next-generation energy storage device. The main problems in cathodes of the lithium-sulfur batteries were outlined and analyzed; the research progress on Li₂S-based composites combined with different host materials (including carbon-based materials, polymer, and inorganic metal compounds) was reviewed and discussed, and the structural characteristics of the representative materials and the methodologies for the performance improvement were analyzed for these cathode materials, together with an outlook for the research activities focusing on the future Li₂S cathode materials.