This bimonthly review paper highlights 100 recent published papers on lithium batteries. We searched the Web of Science and found 3128 papers online from Apr. 1, 2022 to May 31, 2022. 100 of them were selected to be highlighted. High-nickel ternary layered oxides, LiNiO₂-LiCoO₂ and Li-rich oxides as cathode materials are still under extensive investigations for surface coating, preparation of precursors and structural evolution with cycling. Reasearchs for anode focus on surface coating of the composite SiO/C anodes, 3D structure design and surface reconstruction of metallic lithium anode. Various solid state electrolytes including oxide, sulfide and composite materials have been studied. Meanwhile, large efforts are still devoted to liquid electrolytes for the optimizing the electrolyte for Li or graphite anode, and the high-voltage cathode materials, suppressing dissolution of transition metal ions and side reaction as well as improving low tempretuature performance and safety of Li-ion cell. For solid-state batteries, there are a few papers related to the design of composite cathode, bi-layer electrolyte, and inhibition of Li dendrite and side reactions. Other relevant works are also presented to cathode design of lithium sulfur battery using liquid electrolyte, lithium supplement and prelithiation technology. The characterization techniques are focused on dissolution of transition metal ions and structure transformation of layered oxides, SEI formation, electrochemical and chemical stability of the sulfide electrolytes. Theoretical simulations are directed to lithium-ion transportation mechanism in solid electrolytes and solid state electrolyte/Li interface.

Soft carbon is an ideal anode material for fast-charging lithium-ion battery which has the high rate-performance, high reversible capacity, and good compatibility with electrolytes. It has been discovered that soft carbon's electrochemical performances can be further enhanced by pore-making treatment, but a systematic study on the relationship between pore structure and electrochemical performance is still absent. Thus, in this study, soft carbon materials with various pore structures were prepared using the various precursor materials, including Jinzhou and JEF needle coke. The SEM, XRD, Raman, and N₂ isothermal adsorption were employed to examine the changes in microstructure for as-obtained soft carbon materials; The CV, GCPL, EIS, and GITT were employed to examine the effect of pore size distribution on their electrochemical performance. It was discovered that the micropores in soft carbon contributed less to the irreversible capacity during first cycling. When there are suitable micropores (63%) in soft carbon, the lithium-storage capacity and kinetics can be improved without sacrificing the Coulombic efficiency and cycling stability, therefore attaining both high capacity and rate performance.

Pouch-type Na-ion batteries were fabricated using Prussian blue (PB) as cathode and hard carbon (HC) as an anode, and their abuse performance was analyzed. With modest changes in internal resistance, the discharge plot and discharge capacity of the battery was well recovered after overdischarge to 0 V. The battery could still charge and discharge normally after a profound overdischarge to -3.6 V. After overcharging by 20%, 30%, and 40%, the capacity could be recovered to 97.9%, 91.6%, and 88.6%, respectively, and the battery after a 20% overcharge step revealed comparable cycling performance with the battery without overcharge. The batteries passed nail piercing, short circuit, and heating tests without igniting or exploding, and there was no substantial temperature increase following the short circuit test. The findings showed that Na-ion batteries with a Prussian cathode had excellent abuse tolerance, indicating that they might be used for large-scale energy storage.

In this research, a pouch lithium-ion battery was fabricated using Li(Ni_0.8Co_0.1Mn_0.1)O₂ as cathode material and synthetic graphite as anode material. Three different N/P ratios were designed by changing the capacity of the anode. The cell initial capacity, first discharge efficiency, initial internal resistance, rate discharge, high and low temperature discharge, high-temperature storage, and cycling performance were investigated, and the findings indicate that increasing the N/P ratio can improve the battery's initial discharge capacity. However, increasing the N/P ratio will increase the potential of the positive electrode, and the electrolyte will be easily oxidized on the positive electrode side. The low N/P ratio may ensure that the positive electrode has a lower electrode potential, reducing side effects and improving high-temperature storage and cycling performance. However, the N/P ratio is substantially smaller, and Li⁺ is easily lowered, resulting in a loss of active lithium.

Charge and shelf tests on an all-vanadium liquid flow battery are used to investigate the open-circuit voltage change during the shelving phase. It is discovered that the open-circuit voltage variation of an all-vanadium liquid flow battery is different from that of a nonliquid flow energy storage battery, which primarily consists of four processes: jumping down, slowly falling, slowly rising, and stabilizing. The four stages of an all-vanadium liquid flow battery's open-circuit voltage are first evaluated step by step in this study, and then, the causes and influencing elements for the gradual growth of the open-circuit voltage are investigated. The experimental results demonstrated that the slow rise of the open-circuit voltage of the all-vanadium liquid flow battery is related to the volume share of the electrolyte in the battery and flow rate, which is an important feature of the all-vanadium liquid flow battery during the end of charge and shelf phases. The slower the open-circuit voltage rises, the less the volume proportion of electrolyte in the battery. The steady rising of the open-circuit voltage becomes shorter and smaller as the electrolyte flow rate increases.

A hybrid capacitor is a novel form of energy storage device that combines the advantages of both a lithium secondary battery and a supercapacitor. It is widely used in the field of electrochemical energy storage. The electrode materials of hybrid capacitors include those electrode materials used in lithium-ion secondary batteries and supercapacitors, contributing to the "cross structure" formed in the hybrid capacitor. (NCM + AC) hybrid-positive and hard carbon-negative electrodes were prepared using dry and wet processes, respectively, and the 064060 flexible packing hybrid capacitors were assembled. The features of the two electrode architectures are extensively examined, as well as their effects on the performance of the flexible packing hybrid capacitor. The findings of the experiments demonstrate that the dry electrode has a lot of PTFE fiber structures and that the particles in the raw material are closer together. Under the same thickness, the dry electrode has higher loading active material, higher volume density, and smaller ohmic and polarization resistances than the wet electrode. In comparison with those of the wet electrode product, the capacity and energy density of the dry electrode product rise by >20% in the same volume of flexible packaging product. Under the condition of the same ratio of positive to negative electrode in areal density and in discharge capacity, the life of high-and low-temperature, cycle, rate charge-discharge, and high-temperature endurance tests of dry electrode products are better than those of wet electrode products. Dry electrode preparation is solventless, environmentally friendly, and cost-effective, and its PTFE fiber can securely connect NCM and AC, making it ideal for hybrid capacitor electrode preparation.

Sr、Ni co-doped La_0.7Sr_0.3Fe_0.9Ni_0.1O_3-δ (LSFNi) electrode was synthesized using a sol-gel method. The oxidation of CO electrochemically on LSFNi was studied. The results demonstrate that the LSFNi electrode has good chemical compatibility with LSGM and GDC electrolytes. Furthermore, the conductivity of the LSFNi bar increases with the increasing temperature in the 5% H₂-Ar, and the maximum conductivity of 0.85 S·cm^-1 was obtained at 850 ℃. The peak power density of LSFNi-GDC/LSGM/LSFNi-GDC symmetric cell reaches 470, 288, 196, and 130 mW·cm^-2 at 850 ℃, 800 ℃, 750 ℃, and 700 ℃, respectively. Furthermore, the polarization resistance (R_p ) of the symmetric full cell at the same condition is 0.64, 1.01, 1.83, and 3.82 ?·cm², respectively. The charge transfer mechanism and adsorption/desorption of CO are slower than those of H₂, resulting in a somewhat poorer electrochemical property. In the end, the symmetric cell exhibits a reasonable short stability with a degradation rate of 0.003 V·h^-1 at 850℃ under a constant current density of 600 mA·cm^-2.

This study proposes a novel sulfated roasting defluorination and water leaching technique to recover precious metals from wasted lithium iron phosphate (LiFePO₄) batteries cleanly and efficiently. The air atmosphere and temperature of 575 ℃ were determined as the appropriate thermal decomposition conditions of binder by TG-DSC and XRD. By using orthogonal and single-factor experiments, the effects of concentrated sulfuric acid dosage, roasting time and temperature, liquid-solid ratio, temperature, and time of water leaching on the leaching rate of Fe, P, and Li from spent lithium iron phosphate electrode mixture powder and the residual rate of F in the leaching solution were investigated. The optimal roasting process conditions were determined as follows: 0.75 times the theoretical amount of concentrated sulfuric acid, roasting time of 2.5 h, and roasting temperature of 110 ℃. The optimal water leaching process conditions were determined as follows: liquid-solid ratio of 4∶1, a temperature of 60 ℃, and time of 2 h. Under these conditions, both the leaching rates of P and Fe are up to 100%, the leaching rate of Fe is 98.85%, and the residual amount of F in the leaching solution is only 13.11%.

Owing to their low cost, safety, high availability, ecological friendliness, and easy preparation, zinc-ion batteries have been extensively investigated. Linking with the other parts of zinc-ion batteries, the electrolyte is strongly related to making the most beneficial electrochemical performance. To further enhance the possibility of application, it has key importance to enhance the release of electrochemical performance of the batteries. Although there has been a lot of research performed and several batteries' remarkable findings have been attained, some challenges of electrolytes in zinc ion batteries still require to be paid enough attention. In this review, the general principle of zinc-ion batteries is introduced first and then the recent advances in a wide range of electrolytes for zinc-ion batteries involving aqueous, organic, gel, and all-solid-state electrolytes are explained. The solvation problem, corresponding modification strategies, and mechanism of improving electrode stability by additives are introduced in the aqueous electrolytes part. The enhancement of electrochemical performance of the batteries is explained in the organic electrolytes part. The formation principle of related electrolytes and their application in flexible energy storage is explained in the gel part. In the all-solid-state part, the benefit of liquid-free and intrinsic conductivity are briefly illustrated. Furthermore, the electrolytes' research progress in zinc-ion batteries is summarized and the prospects research directions of those are proposed.

Electrode is a vital component of all vanadium flow batteries and the place where the redox reaction occurs. High conductivity, big specific surface area, superior wettability, corrosion resistance, and low cost are all characteristics of an ideal flow battery electrode. Carbon compounds generated from biomass have a porous structure and are high in oxygen functional groups, as well as nitrogen, phosphorus, sulfur, and other elements. They are widely employed in electrode materials by providing active sites on surface. In this research, we review the application and research progress of biomass-derived carbon materials as electrodes or electrode catalysts in all vanadium flow batteries. The materials' structure, composition, and electrochemical characteristics are examined in detail. It will aid in the improved design of electrode materials, as well as the performance, cost reduction, and industrialization of VFB.

Silicon is an important material in the development of high specific energy lithium-ion batteries due to its high theoretical capacity. However, during the cycle process, silicon has huge volume changes. This causes the negative material to be pulverized and fall off, which affects the battery's electrochemical performance. As an important part of the electrode, the binder can stabilize the anode structure and improve battery performance. Thus, this review summarizes research related to silicon-based anode binders, e.g., synthetic polymer and biopolymer binder. Synthetic polymer binders primarily include polyacrylic acid, polyvinylidene fluoride, and conductive binders, and biopolymer binders primarily include carboxymethyl cellulose, sodium alginate, and other biological binders. The selection conditions of a silicon-based anode binder are analyzed in this paper. The silicon-based anode binder should have polar functional groups, certain elasticity and mechanical strength, high chemical stability, and preferably certain conductivity. Polar groups can form hydrogen bonds with hydroxyl groups on the surface of silicon to enhance the bonding properties between materials. To better restrict the volume expansion of silicon, it can be modified to possess elastic properties and self-healing ability. Some conductive materials can also be selected to make the binder have conductive properties. This can improve the stability of the conductive network inside the electrode and increase the content of active substances. In addition, concepts related to the selection and development of a binder are discussed.

A solid electrolyte is an ideal electrolyte material with high energy density, high capacity, and high safety. Inorganic solid electrolytes have high ionic conductivity and mechanical properties; however, they exhibit high impedance and poor with contact electrode. Polymer solid electrolytes have good flexibility and machinability; however, their ionic conductivity does not satisfy application requirements. Organic-inorganic composite electrolytes possess the advantages of inorganic and polymer solid electrolytes; thus, these materials are suitable for a wide range of applications. However, the ionic conductivity and electrochemical stability of these materials are not satisfactory. Thus, in this study, we reviewed the last 30 years of literature on organic-inorganic composite electrolytes from the Web of Science Core Collection database. Relevant data were then visualized using CiteSpace. In addition, important nodes in composite electrolyte development process and recent research hotspots were analyzed. The results demonstrate that research interest in composite electrolyte is increasing exponentially. The latest research focuses on the gel state, single-ion conductor structures, and polycarbonate-based materials. Interface is the key to the study of composite electrolytes and has been the most observable key word over the past five years. We found that future development of composite electrolytes should focus on (1) material selection and structure design of semisolid composite electrolyte, (2) interface structures and transport mechanisms between different phases in the electrolyte, and (3) a stable and elastic SEI/CEI film was constructed between an electrolyte and electrode.

Having a substantial impact on the energy conversion efficiency of supercapacitors, self-discharge is an essential metric to consider when evaluating their performance. Understanding the self-discharge mechanism, creating realistic simulation models, and designing optimal procedures are all necessary for supercapacitors to be practical. However, many types of research were just concentrated on the improvement of other parameters, e.g., energy/power density and lifespan. Less attention has been paid to the self-discharge performance of supercapacitors. Consequently, the progress of supercapacitor self-discharge research in recent years is discussed in this work to support the growth of self-discharge research. The influencing factors and mathematic models for different self-discharge mechanisms (charge redistribution, activation control, diffusion control, and potential driving) are summarized in detail. Self-discharge limitation approaches using several tactics (charging proposal, surface-chemistry alteration, electrode coating, and functional electrolyte/separator) are also discussed. This paper emphasizes that the corresponding works should be performed in three aspects in the future: First, it is necessary to develop an accurate evaluation system of self-discharge according to various application requirements. Second, to build a reliable identification technique for distinct self-discharge processes and identify their origins, simulation approaches must be combined with modern characterization technologies. Finally, it is necessary to establish specific optimization methods according to the different self-discharge mechanisms to achieve the simultaneous optimization of self-discharge and other electrochemical performances.

Cold storage technology is a key technique of reducing the power grid's peak-to-valley disparity and achieving peak control of the load side of the power grid. Hydrate as a cold storage medium has some advantages such as high cold storage capacity and high phase transition temperature. In this study, aliphatic and aromatic amino acids are used as green additives to investigate the influence of amino acid side chains on HCFC-141b hydrate formation and cold storage capacity. The experimental results demonstrate that the addition of five amino acids can effectively shorten the induction time of HCFC-141b hydrate formation and significantly increase hydrate production and the cold storage capacity in HCFC-141b hydrates. Among them, the experimental system with the addition of valine has the highest cold storage capacity in hydrates in this study, which is approximately 261.24 kJ/kg. It is much higher than that in the pure water system, which is approximately 57.83 kJ/kg. The experimental system containing tryptophan has a larger average cold storage capacity in hydrates than the system containing aromatic amino acids, which is approximately 222.14 kJ/kg. The cold storage capacity is lower than that in the experimental system with the addition of valine. It can be shown that amino acids can stimulate hydrate formation, with amino acid side chain groups and hydrophobicity being the key elements that influence hydrate formation kinetics. The aromatic amino acid side chain groups have stronger effects on reducing the induction time and increasing the hydrate growth rate than the aliphatic amino acid side chain groups. The aliphatic amino acid side chain groups are more favorable to increasing hydrate synthesis and cold storage capacity. Amino acids exhibit surface activity that facilitates the dispersion of certain HCFC-141b into the water phase and increases the contact area between water and HCFC-141B, which promotes the formation of hydrates.

Thermochemical heat storage plays an important role in promoting utilization of renewable energy and achieving the "double carbon" goal due to its high heat storage density and nearly zero heat loss in the storage process. Thus, the design and performance optimization of thermochemical reactors are important. In this paper, we describe a two-dimensional simulation model constructed to investigate thermochemical reactor discharge using silica-gel as a heat storage material. By adjusting the model's parameters, e.g., the maximum water absorption, affinity coefficient, inhomogeneity, the preexponential factor, and the activation energy of the silica gel sphere, the results of a numerical simulation and experiment at reactor outlet temperature were in good agreement. We found that the affinity coefficient parameter, inhomogeneity parameter, and maximum water absorption of the silica gel sphere had more influence on the air outlet temperature among all considered parameters. The specific heat capacity was the least. When the heterogeneity parameter was increased from 1.2 to 2.8, the maximum air outlet temperature decreased from 140 ℃ to 70 ℃. The pre-exponential factor was found to have greater influence on air outlet temperature than activation energy. In addition, increasing the specific heat capacity of the silica gel reduced the maximum outlet temperature of the reactor and helped prolong the time required to reach the maximum outlet temperature. Combined with the experimental data of a small-scale reactor, the performance of a large-scale heat storage device can be predicted accurately after multiple charge and discharge cycles. Thus, the reactor and system design can be optimized.

A coupled thermal stress integration model of the molten salt-packed-bed thermal storage tank is developed. The dynamic thermal and stress performances under various charging and discharging cycles are calculated using this model. High-temperature creep and plastic yield failure areas are also explored. For the single cycle, the results demonstrate that ①there exist four variation tendencies of the tank wall temperature: sharply rise and stabilization stages in the charging process, gently decline and sharply decrease stages in the discharging process. Meanwhile, the creep phenomena would occur at the tank's outermost portion. ②The 1-5 shell section walls are in an elastic condition with lower stress levels, resulting in stress concentration at the bottom. Besides, the peak stress presents the first rise and then fall tendencies in the charging and discharging processes, respectively. ①The highest temperature of the tank wall displays a cyclic fluctuation condition between 631 and 836 K over the multiple cycles. Under the impact of decreased stress and creep, damage to the tank wall in the elastic condition would likely accrue, increasing the danger of tank failure. ②Particularly, because the peak stress of the inner wall also varies in the period between 275 and 423 MPa, the low-cycle fatigue fracture failure is induced by the high stress (greater than yield strength) that could occur during the charging and discharging cycles. This research might give a useful reference approach for determining the fatigue life of a packed bed tank under dynamic load.

The model of multi row tube bundle phase change heat storage unit is developed, and the effects of a varying number of tubes in the square cavity, as well as various arrangement approaches and tube wall temperatures on the heat storage and release of phase change heat storage unit are numerically simulated. The findings reveal that the natural convection can be improved and the heat transfer area between the circular tube and the surrounding fluid can be increased, with an increasing number of tubes, that is, the change of the arrangement mode and the corresponding liquid phase curve almost changes linearly at the first, and the curve's slope increases gradually with the number of tubes' increase. The findings reveal that the arrangement's change can hasten the melting and solidification process of PCM and substantially improve its heat storage and release performance. Additionally, the pipe wall temperature also has a crucial effect on the heat storage and release performance, but the influence decreases with the pipe wall temperature's increase.

This paper was written under the premise of ensuring the same water tank structure size, phase change material type and dosage, and water temperature and flow rate at the tank's inlet to investigate the impact of different shape encapsulation units on the heat storage and release performance of phase change energy storage tanks. Fluent software is applied to simulate the phase change energy storage tank with plate type, cylinder type, spherical type encapsulation unit, and the traditional water tank without phase change material. The research next examines the variations in each water tank's heat storage duration, heat release time, temperature distribution, and heat storage and release capacity. The simulation results show that the shape change of the encapsulation unit will have some influence on the heat storage and release performance of the water tank. The spherical unit water tank is the first to complete heat storage and release during the heat storage and release process. The heat storage and release times are both reduced by 10% and 2.3%, respectively, when compared with the plate and cylinder unit water tanks. It takes the longest time for the plate unit water tank to complete heat storage and release, compared with the traditional water tank, the heat storage time is extended by 54.8% and the heat release time is extended by 38.7%. The cylindrical unit water tank has the highest heat storage capacity, at 41.612 MJ, which is 16.1% more than a typical water tank. Plate unit water tank releases the most heat, the heat release capacity is 41.634 MJ, compared with the traditional water tank increased by 16.2%. The temperature distribution in the spherical unit water tank shows a trend of increasing or decreasing along the height direction, which is quite different from the other two-phase change energy storage tanks, and there is an inadequate heat transfer zone due to the different shape and arrangement of encapsulation units.

Safe, efficient, low-carbon, and clean energy has become the dominant path of energy development, and an integrated energy system is one of the most effective strategies to minimize pollution emissions and enhance energy efficiency. To realize the economic and low-carbon operation of the system, this study proposes a low-carbon optimal scheduling strategy for an integrated energy system considering a reward and punishment ladder carbon trading mechanism and an integrated demand response strategy. To begin, an integrated demand response model for cooling, heat, and electricity multiple loads is provided based on the flexible properties and schedulable value of multiple loads. A response compensation technique is developed on this basis.Second, addressing the uncertainties of renewable energy, The Latin hypercube sampling method and kantorovich scenario reduction method are used to generate typical scenarios of the predicted output of photovoltaic, wind power, and load and the reward and punishment stepped carbon transaction cost is introduced into the optimal scheduling model, and the optimization objective function with the lowest sum of system operation cost, response compensation cost, and carbon transaction cost is established. Finally, the CPLEX toolbox solves the given model. The impacts of the integrated demand response technique and the reward and punishment stepped carbon trading mechanism on the operation optimization, energy conservation, and emission reduction of the comprehensive energy system are evaluated in the example simulation. It has been demonstrated that the developed model and approach can effectively account for the system's economic and environmental advantages

Improved frequency modulation capacity of coal-fired thermal power units is one of the key strategies to fulfill the present frequency modulation demand of new energy in the power grid, in the context of rising grid-connected capacity of new energy. Consequently, the hybrid energy storage system composed of flywheel energy storage and electrochemical energy storage is an important technical means to enhance the frequency modulation performance of thermal power units. In Matlab/Simulink, a simulation model of a hybrid energy storage system to aid frequency modulation of coal-fired thermal power units is created, with the suggested control method confirmed and simulated for a 600 MW heat supply unit. The results demonstrate that the coupling hybrid energy storage system can effectively reduce the frequency variation of the power grid, reduce the output power fluctuation of the turbine, and stabilize the main steam pressure. The fuzzy control approach is utilized to optimize the power distribution coefficient in the hybrid energy storage system. The findings demonstrate that the fuzzy control method can keep the continuous charging/discharging process adaptable to power variations.

The pumped storage power plant is reliable and flexible, with the ability to adapt swiftly to load changes. When the storage station was previously operational, the load distribution between units did not always take into account the differences in operation characteristics between the units, which resulted in higher energy consumption during operation. For this issue, this study considers energy balance and unit operation constraints and develops a two-layer optimization model with the optimal overall efficiency of the extraction and storage system. The top model primarily optimizes the grids storage system scheduling mode and gives power instructions to the bottom model. The lower model is mostly based on the difference in water turbine and water pump efficiency, and the loads power requirement should be evenly divided among the units to match the real power grid requirement. The results demonstrate that the proposed strategy effectively promotes the operation and economic efficiencies of the storage station.

Because of several contributing factors, it is difficult to correctly anticipate electric vehicle carbon emissions. As a result, a strategy for predicting carbon emissions from electric cars during their whole life cycle is suggested, taking into account temporal correlation. On the whole life cycle theory, measuring marginal electricity, and coal production line loss, suggestions produce carbon emissions, and the carbon emissions formed by coal transportation link power link's carbon footprint, and applies time correlation to the analysis of characteristics of the electric car driving, calculate direct carbon emissions, to complete consideration of time correlation prediction in the whole life cycle of the electric car carbon emissions. The experimental findings reveal that the proposed measuring technique has high accuracy in carbon emission forecast under vehicle uphill, downhill, congestion, and regular driving scenarios, which satisfies the requirement for electric vehicle carbon emission prediction.

Large-scale grid integration of renewable energy reduces the level of inertia and anti-disturbance ability of power systems, weakens the frequency stability of the power grid, and increases the difficulty of primary frequency modulation (PFM) of the power grid. Facing the increasing pressure of frequency modulation, an energy storage system that responds to the PFM of the power grid is required. This paper introduces the principles of the nickel-metal hydride (Ni-MH) battery. Then, combined with operational condition data of 660 MW thermal power units participating in PFM in Northwest China, the optimal power/capacity configuration results and coordinated control strategy suitable for an Ni-MH battery energy storage system are proposed. In addition, high-power Ni-MH batteries, modules, and systems are developed for energy storage systems with a target capacity of 5 MW/0.5 MWh. The charge and discharge curves, cycle life, consistency, and PFM conditions of the batteries, modules, and systems were evaluated. Experimental data results demonstrate that the high-power Ni-MH batteries presented in this paper exhibit high charge and discharge rates of 10 C and 480,000 cycles under short-time and high-frequency working conditions. The modules and systems work stably under high-power test conditions. The results of this study verify the application potential of Ni-MH battery energy storage technology in the PFM of thermal power.

Consisted of batteries, large storage has a vital role in clean energy high penetration power system, short circuit calculation, and protection configuration are very significant. This study begins by proposing a single battery short circuit model, which is then validated via a short circuit test. On the basis of the model, short circuit calculation formulas inside and between clusters are deducted, which can be implemented widely in a large storage system with arbitrary battery numbers and cover all kinds of short circuit conditions. In this case, the error between theoretical calculation and simulation is <4%, which meets the protection analysis criteria. Factors and change rules of the short circuit are analyzed, the more inter batteries the larger the other clusters and short circuit point current when the fault happens inside the cluster, and module difference affecting short circuit current is proposed. The benefits and drawbacks of different protection schemes are examined, a protective configuration scheme based on fuses is offered, and the ideal fuses installation site is investigated. This scheme summarizes the most important short circuit current estimation techniques for each fuse. The protection configuration scheme proposed by this research covers short circuit current calculation, device selection, and many other aspects, which can be applied widely in the early-stage scheme design of different large storage battery substations.

Motor is the core of flywheel system to realize the mutual conversion of electric energy and mechanical energy. BLDC motor has the advantages of small volume, low noise and high economic benefit. It has been applied in energy storage. In order to avoid large winding loss during the charging and discharging process of the motor or introduce auxiliary circuit to stabilize the output voltage, based on the BLDC motor model applied to flywheel energy storage, a motor charging and discharging control strategy is proposed to change the turn-on and turn-off sequence of thyristor, change the winding back EMF and current flow direction, and realize the charging and discharging function of the motor. The simulation results show that the BLDC motor model can correctly represent the operating characteristics of the flywheel. It also shows that the proposed motor charge discharge control strategy can make the motor absorb power in the charging state, convert electric energy into flywheel kinetic energy, release power in the discharging state and convert flywheel kinetic energy into electric energy without introducing additional circuit topology, And the relevant electrical quantities are controllable in the process of charge and discharge, so as to realize the two-way flow process of power. The design of this control strategy provides a certain theoretical basis for the realization of mechatronics products of flywheel energy storage.

The nonlinear programming equation is produced by using the least fluctuation of the output power of a thermal power plant as the goal function, taking into account the operation features and restrictions of a wind-photovoltaic-thermal-storage multi-energy system. The whale optimization algorithm is enhanced by introducing nonlinear adaptive weights coefficient S1 and S2 in the process of encircling prey, bubble-net attacking, and searching for prey, which can coordinate the global search and local search ability of the algorithm. In a multi-energy system that includes wind, solar, and thermal storage, the enhanced method is utilized to solve the optimal design issue of an energy storage power station. The IEEE33-node system is used as the simulation model. The energy storage is positioned at the 13th node, with a configured capacity of 40.2 MWh and an ideal running cost of 13.29 million yuan per year, according to the findings of the upgraded whale optimization algorithm. The results demonstrate that the energy storage configuration strategy proposed in this study can effectively suppress the power fluctuation of the thermal power plant in a multi-energy system, and the peak-valley difference of thermal power plant decreases by 90.79% after the addition of energy storage, which effectively assists in the peak regulation. The optimal configuration technique described in this study is beneficial in boosting the development and construction of energy storage power plants and will give essential assistance for attaining the objectives of "dual carbon" and fostering energy revolution.

Electricity costs are the second largest production cost in the nonwoven fiber process. A key measure is how to reduce electricity costs and improve profitability. Based on the power consumption strategy of "peak valley flat price" implemented by the state to encourage peak shaving and valley filling of electric power, a single-tank energy storage and heat exchange system for fiber sizing based on energy storage technology is proposed in this paper, and the design methodology of its key parts is described. Combined with the application case of a textile enterprise in Hebei, the economy of the system is analyzed. Through theoretical calculation, using the proposed energy storage heat exchange system can reduce electricity costs by approximately 38% compared to convention fiber heating devices. Due to the cycle of the single pot working medium heat exchanger output drop, must use electric heater can guarantee the process operation, actual saving electricity costs about 25%, which is good economical. This paper also provides support for the application and design methodology of energy storage technology in the textile industry.

A symmetrical serpentine channel design is proposed in this paper to solve problems related to long flow path, large pressure difference, and high energy consumption of coolant in the traditional serpentine channel design. The COMSOL Multiphysics finite element software was used to establish the model for the proposed designed. The pressure drop of the proposed design is reduced by 42.8% compared to the traditional serpentine channel because the flow rate in the subchannel and linear loss along the cooling channel are reduced. In addition, the temperature uniformity of the symmetrical serpentine flow channel is superior to that of the traditional serpentine flow channel. Despite the fact that the coolant temperature increases along the flow direction, the temperature distribution of the battery in the coolant flow direction is relatively uniform, and the temperature difference is small. The maximum temperature difference of the battery occurs in the direction of the thickness of the battery because the thermal conductivity in this direction is too small. When the thermal conductivity in the direction of the battery thickness increases to 10.925 W/(m·K), the temperature difference in the battery thickness direction is much smaller than that in the coolant flow direction. With the proposed design, the maximum temperature difference of the battery is reduced from 2.75 ℃ to 1.24 ℃ (a 54.9% reduction). Thus, improving the thermal conductivity in the battery thickness direction has a significant effect on improving the battery's temperature uniformity. In addition, the influences of coolant flow rate and channel width are discussed. Results demonstrate that although the increased coolant flow rate can reduce the maximum temperature and temperature difference of the battery, the system's energy consumption increases sharply. Expanding the channel width reduces the channel pressure drop significantly, and the effect on battery temperature is insignificant.

Based on the heat production characteristics of square lithium-ion batteries, a sort of bionic wing vein channel cool plate was developed. Based on numerical heat transfer theory, a liquid-cooled heat dissipation model of the battery pack is developed for the cold plate of the bionic wings vein channel, and the numerical simulation calculations were performed on the lithium-ion battery packs of the two parallel flow channel cold plates with various inlet and outlet positions and the bionic wings vein channel cold plate. The impact of the neighboring cold plates of the battery pack's cooling liquid flow direction and channel depth on the heat dissipation of the bionic wings vein channel cold plate is investigated. The results demonstrate that when compared with the cold plate in the parallel channel, chilling the cold plate in the bionic wing channel may lower not only the maximum temperature and temperature difference of the battery pack but also the pressure loss of the flow channel and the energy consumption. Compared with that of the battery pack in the same direction. the maximum surface temperature of the adjacent cold plate coolant in the staggered flow of the battery pack decreases by 0.62 K and the temperature difference decreases by 1.13 K. The average temperature change is not significantly different, and the temperature field distribution homogeneity has improved. The coolant mass flow rate remains constant, while the battery pack's maximum temperature, average temperature, and temperature differential rise initially, then fall as the groove depth increases. However, as the depth of the channel increases, the weight and space occupied by the battery pack will also increase. The cooling effect of the cold plate is optimal when the channel groove depth is 2 mm. The findings might be used to investigate the thermal management of battery packs with improved heat dissipation and decreased energy usage.

A serpentine pipeline battery pack thermal management system with a unidirectional flow structure and bidirectional convection structure was designed for a square lithium iron phosphate battery for electric vehicles, respectively, to address the problem of high surface temperature and poor temperature uniformity during discharge of a large-capacity square lithium-ion power battery pack. To examine the cooling performance of the two thermal management systems, the electrochemical-thermal coupling model of a single cell was firstly developed, and after the model was confirmed experimentally, the maximum battery pack temperature, cooling time, and maximum temperature difference under various mass flow rates were compared and simulated. The cooling time of the unidirectional flow structure is shorter than that of the bidirectional convection structure, and the maximum temperature difference of the bidirectional convection structure's battery pack is smaller than that of the unidirectional flow structure; under a large mass flow rate, the coolant temperature will rise due to the rapid coolant flow rate, affecting the cooling effect.

Accurate prediction of lithium-ion battery capacity is advantageous for enhancing battery safety and avoiding battery abuse. An accurate capacity prediction has always been a challenge in battery management systems due to the effect of complicated internal electrochemical reactions and external variables. To achieve an effective and accurate prediction of lithium battery capacity in the full-service life, this study proposed an Elman neural network battery capacity prediction model optimized by a genetic algorithm. To begin, the typical characteristics of discharge capacity growth, internal resistance, and temperature data collected over various battery cycles were chosen to adequately depict the law of battery aging and capacity degradation. Secondly, the principal component analysis algorithm is used to reduce the dimension of the characteristic quantities to reduce the data dimension of the training quantity. The Elman neural network is then used to build the battery capacity prediction model. To ensure efficient and accurate prediction of battery capacity, a genetic algorithm is used to adjust the weights and thresholds of the Elman neural network. Finally, the model was verified on different batteries. The verification findings reveal that the GA-Elman neural network prediction model is more accurate and efficient than the classic Elman neural network and LSTM neural network prediction models. The maximum mean absolute error, maximum root mean square error, and minimum fitting coefficient of the model is 0.92%, 1.02%, and 0.9679, respectively, for various batteries, showing that the model can accurately predict the capacity of lithium battery in the process of decay and has high adaptability to different batteries.

Distributed energy storage system (DESS) is very important for peak shaving of the power system. Its location and capacity arrangement has traditionally made it a focus for field study. However, poor economic and technical analyses, as well as DESS's high processing cost, remain issues. In light of this, this research provides a greedy algorithm-based optimum capacity allocation strategy for a DESS. First, a comprehensive DESS economic model and operation constraint model are established. Compared with the traditional defect of only considering investment and operation costs, it increases the economic benefits brought by energy storage operation scheduling. Then, using power loss sensitivity, site selection can lower the dimension of the addressing problem and enhance optimization efficiency. Then, the greedy algorithm is used to divide the DESS into many units and optimize them, and the decision-making process of each unit is simplified into a simple model, which can significantly improve the solution efficiency. The simulation study is conducted in MATLAB R2015b to validate the efficiency of the suggested technique, using load data from a neighborhood in Jiaxing City, Zhejiang Province, as an example. The results show that (1) when compared with evolutionary algorithms, this approach can only find the local optimal solution, and the economic gain is slightly smaller (albeit the difference is modest), but it can greatly improve computing efficiency and (2) the optimization results are identical to the entire optimization, but it excludes the computation of network loss cost, resulting in increased calculation efficiency.

Lithium-ion battery is an important part of different energy storage systems and equipment. An accurate forecast of lithium-ion battery remaining usable life is critical for guaranteeing the dependability and safety of battery-related enterprises and facilities. In this study, a new data-driven method is proposed to enhance the low forecasting accuracy and poor generalization performance in the remaining useful life prediction of lithium-ion batteries. Poor performance is frequently the result of a single data-driven strategy and is caused by non-stationary, nonlinear dynamics in battery deterioration dynamics. The proposed method is based on variational filtering, data wrapping, and a deep fusion network. First, the random noise interference of the original battery degradation sequence is eliminated to obtain the relatively stable degradation characteristic data by using the variational filtering method. Then, using the optimum embedding approach to accomplish feature data wrapping and limit information loss, an unique deep fusion network is constructed to model non-linear battery deterioration data, detect the degradation pattern in the battery data, and realize the final remaining usable life prediction. Lastly, remaining useful life prediction experiments are conducted on the lithium cobalt oxide battery data set and the average root means a square error of prediction is 1.41%, and the average absolute error of remaining useful life of prediction is less than two cycles. The suggested technique provides strong generalization, high forecasting accuracy, and minimal prediction error and can successfully anticipate the deterioration process of lithium-ion batteries, according to experimental data.

Recently, Li-ion battery safety accidents in the fields of energy storage and electric cars have become more common.The study of failure mechanisms and the improvement of lithium-ion battery safety and dependability has become a research hotspot. The failure behaviors of a lithium-ion battery are of various forms, greatly hazardous, and complex to assess and detect. Traditional failure mechanism analysis methods destroy and disassemble the battery, making it impossible to adequately characterize and forecast a safety mishap. It is thought to be a more scientific and effective approach to analyzing the possibility of an accident with the Li-ion battery or pack's reliability. However, the research on battery pack reliability has just started, and there are some shortcomings, such as the coupling of multiple physical fields cannot be considered, and the analysis error is large. The reliability analysis meaning of Li-ion batteries is first explained in this study, followed by current research progress and existing challenges of reliability modeling and analysis methodologies. The multi-physical field coupling reliability research approach for lithium-ion battery packs is given. The current issues and challenges are examined in depth, and a battery failure analysis technique is proposed by merging the level by level retrospective analysis method based on Bayesian theory with a multiple physical fields coupling model.

The capacity of the battery will continue to fall as the cycle ages, and the internal resistance will progressively grow, affecting the battery's service life and performance. To establish the semi-empirical model of capacity decline and internal resistance growth and shorten the time required to investigate the battery aging characteristics, the 21700 lithium-ion battery with high energy density is adopted to conduct the cycle aging experiment of the battery under six working conditions at 0 ℃, 23 ℃, and 40 ℃ combined with 1 C and 2 C discharge rates. The effect of temperature and other environmental conditions on battery capacity reduction and internal resistance increase is investigated.

When the semi-empirical model of battery capacity decline is created by combining the Arrhenius equation, an additional power function and a constant term about the number of cycles are introduced, which can broaden the model's applicability and make it suitable for different capacity decline trends at different temperatures. A semi-empirical model of battery internal resistance growth is developed using the double exponential function multiplication formula, which can effectively predict the law of internal resistance growth under various working conditions. The cross-validation approach is used to demonstrate the accuracy of semi-empirical models of capacity decrease and internal resistance increase, which may be used to forecast the aging law of batteries at various temperatures. Finally, the semi-empirical model of battery aging is used to predict the capacity and internal resistance of the battery at 15 ℃, 30 ℃, and 45 ℃, allowing for a better understanding of the battery's aging characteristics while avoiding a large number of repeated experiments and increasing research efficiency.

The rise and advancement of energy storage cannot be separated from policy encouragement and mechanism support. Australia has a mature free power market, which provides the basis and conditions for energy storage to create a business model. Meanwhile, Australia has altered legislation and market rules inhibiting the growth of energy storage in recent years, progressively removing the barriers to large-scale application and participation in the power market, which is something China should learn from. In this study, the development status and future market demand for energy storage in Australia are first summarized. The income sources of household energy storage and large-scale energy storage participating in the power market are studied. Furthermore, the Australian Federal government's policy incentives and rule modifications in r&d and demonstration project support, state energy storage-related subsidies, market registration subject identity, transaction settlement mechanism, additional revenue sources, and other aspects are examined in depth. Finally, Australia's enlightenment in China is summarized.

Energy storage development is inextricably linked to policy environment support as crucial technological support for developing a new power system. The European Union has extensive experience in the establishment of a unified and fully competitive power market as the pioneer of power market-oriented reform. At present, it has produced a mature trading system of spot market and power balancing mechanism, which provides favorable conditions for building a business model for energy storage. Simultaneously, the European Union has made regular revisions to top-level policies and power market regulations to promote large-scale energy storage development and provide favorable conditions for energy storage to participate in the power market on a greater scale, which is instructive for China. In this study, the current situation of energy storage is first summarized. Furthermore, from the aspects of the European Union Commission and the Member States, this study introduces the situation of the European Union in R&D funding and storage subsidies, followed by a detailed analysis in terms of identity for market participation, transaction mechanism, and market opening. Finally, the experience of the EU in China is summarized.

In the context of cleaning the global energy structure, Saudi Arabia, which has long been dependent on oil, has proposed energy transition and diversification in its economic development. This paper analyzes the motivations and development direction of Saudi Arabia's energy transition and proposes the hydrogen development concept. In addition, this paper quantifies the economics of hydrogen energy development and international trade in the medium and long terms. The results demonstrate that in the short and medium terms, KSA could develop a blue hydrogen industry and construct an industrial chain with abundant natural gas resources. For the long term, the development of green hydrogen with abundant clean energy resources will become an important opportunity for Saudi Arabia's energy transition. In addition, related countries can learn from Saudi Arabia's energy restructuring measures to realize domestic energy transition and hydrogen development.

In the context of "Double Carbon," the penetration of renewable energy generation in the electricity grid is increasing. It advocates for increased AGC frequency control and reserve services requirements. As a newly emerging flexible resource, energy storage has great potential to provide ancillary services. Simultaneously, it faces a trade-off issue between the energy and ancillary service markets. In this context, an opportunity cost analysis approach for lithium battery energy storage in delivering AGC service is provided. An effective capacity allocation mechanism for energy storage between the energy and AGC markets is provided. Case studies reveal that the marginal opportunity cost of AGC capacity for energy storage increase with the growth of the declared AGC capacity. As a result, the return from energy storage is maximized when the marginal opportunity cost of AGC capacity equals the compensation price for AGC frequency control.

Hydrogen is the most suitable energy carrier for smart networks and large-scale renewable energy generation. Currently, the cost of hydrogen produced by water electrolysis is rather expensive, making it uncompetitive for large-scale use in manufacturing, transportation, construction, and other industries. In this study, we have investigated the whole life cycle cost of a hydrogen production plant with water electrolysis and compared the cost composition under different technical routes. According to the findings, the primary elements influencing the total cost of water electrolysis for hydrogen generation are equipment acquisition cost, power cost, and equipment durability. Because of the lower equipment purchase cost, alkaline electrolyzers have lower total hydrogen production costs than proton exchange membrane electrolyzers. The full-life-cycle power consumption of electrolytic hydrogen production plants can be significantly lowered by increasing the operating temperature of the electrolyzer, developing a high-efficiency electrolyzer, and improving the durability of the electrolyzer, thereby reducing the overall cost of hydrogen production. The results demonstrate that reducing the power usage of hydrogen production by 1 kWh/Nm³ reduces the levelized cost of hydrogen by 1.1 P yuan/Nm³ (P is the electricity price, yuan/kWh). When the price of electricity falls, so does the levelized cost of hydrogen. Correspondingly, the electricity price is reduced by 0.01 yuan/kWh, and the reduction in the levelized cost of hydrogen is 0.057 yuan/Nm³.

Aiming at the problems in the experimental teaching of energy storage, this paper uses hardware-in-the-loop simulation technology to incorporate specific actual engineering projects into the experimental teaching. The authors use Simulink to model the energy storage controlled object, use the designed low-code controller for control, and propose an experimental teaching method for energy storage control based on Simulink and low-code controller. The specific process of the method is as follows: in the preparation phase of the experiment, the teacher assigns the students the task of understanding the background of the experiment in advance. During the experiment, it is divided into four parts: control strategy design, controlled object model construction, control strategy realization and result analysis. After the experiment, students are encouraged to deep thinking and extend to other control strategies. Then authors introduce the low-code controller and explain the configuration files in detail. Students only need to fill in the corresponding EXCEL configuration file to realize the control strategy, which reduces the requirements for programming ability and helps them understand the control strategy more thoroughly. Finally, taking the optimization control of energy storage power allocation as an example, it is carried out from four aspects: overall cognition, key enhancement, difficulty analysis and in-depth enlightenment. It completes the real-time simulation of energy storage battery pack charging and discharging, realizes the control goal of energy storage power distribution, verifies the accuracy of hardware-in-the-loop simulation technology and the validity of the proposed energy storage control experiment teaching method.