Batteries, Volume 8, Issue 12 (December 2022) – 43 articles

Aqueous zinc batteries (AZBs) show promising applications in large-scale energy storage and wearable devices mainly because of their low cost and intrinsic safety. However, zinc metal anodes suffer from dendrite issues and side reactions, seriously hindering their practical applications. Two-dimensional (2D) materials with atomic thickness and large aspect ratio possess excellent physicochemical properties, providing opportunities to rationally design and construct practically reversible zinc metal anodes. Here, we systematically summarize the recent progress of 2D materials (e.g., graphene and MXene) that can be used to enable dendrite-free zinc metal anodes for AZBs. Firstly, the construction methods and strategies of 2D materials/Zn hybrid anodes are briefly reviewed, and are classified into protecting layers on Zn foils and host materials for Zn. Secondly, various 2D material/Zn hybrid anodes are elaborately introduced, and the key roles played by 2D materials in stabilizing the Zn/Zn²⁺ redox process are specially emphasized. Finally, the challenges and perspectives of advanced 2D materials for advanced Zn anodes in next-generation AZBs are briefly discussed. Full article

The electrolyte is an important component of lithium-ion batteries, especially when it comes to cycling high-voltage cathode materials. In this paper, we propose an algorithm for estimating both the oxidising and reducing potential of electrolytes using molecular dynamics and quantum chemistry techniques. This algorithm can help to determine the composition and structure of the solvate complexes formed when a salt is dissolved in a mixture of solvents. To develop and confirm the efficiency of the algorithm, LiBF₄ solutions in binary mixtures of ethylene carbonate (EC)/dimethyl carbonate (DMC) and sulfolane (SL)/dimethyl carbonate (DMC) were studied. The structure and composition of the complexes formed in these systems were determined according to molecular dynamics. Quantum chemical estimation of the thermodynamic and oxidative stability of solvate complexes made it possible to establish which complexes make the most significant contribution to the electrochemical stability of the electrolyte system. This method can also be used to determine the additive value of the oxidation and reduction potentials of the electrolyte, along with the contribution of each complex to the overall stability of the electrolyte. Theoretical calculations were confirmed experimentally in the course of studying electrolytes by step-by-step polarisation using inert electrodes. Thus, the main aim of the study is to demonstrate the possibility of using the developed algorithm to select the optimal composition and solvent ratio to achieve predicted redox stability. Full article

The prediction of thermal behavior is essential for an efficient initial design of thermal management systems which equip energy sources based on electrochemical cells. In this study, the surface temperature of various cylindrical types of Li-ion batteries is monitored at multiple points during discharge. Three different battery chemistries and two sizes (18650 and 21700) are considered in this study, allowing the comparison of the influence these parameters have on the temperature rise considering different discharge rates (1C, 2C and 3C). Based on repeated experimental measurements, a simple equation that describes the thermal behavior of batteries is proposed and further used to create 3D thermal maps for each analyzed battery (generally error is below 1 °C but never exceeds 3 °C). The practical utility of such an equation is that it can drastically reduce the time spent with experimental measurements required to characterize the thermal behavior of cylindrical Li-ion batteries, necessary for the initial design process of energy sources’ thermal management system. Full article

In recent years, the goal of lowering emissions to minimize the harmful impacts of climate change has emerged as a consensus objective among members of the international community through the increase in renewable energy sources (RES), as a step toward net-zero emissions. The drawbacks of these energy sources are unpredictability and dependence on nature, leading to unstable load power supply risk. One way to overcome instability in the power supply is by using a battery energy storage system (BESS). Therefore, this study provides a detailed and critical review of sizing and siting optimization of BESS, their application challenges, and a new perspective on the consequence of degradation from the ambient temperature. It also reviews advanced battery optimization planning that considers battery degradation, technologies, degradation, objective function, and design constraints. Furthermore, it examines the challenges encountered in developing the BESS optimization model and evaluates the scope of the proposed future direction to improve the optimized BESS, especially its battery. Full article

The battery is an important part of pure electric vehicles and hybrid electric vehicles, and its state and parameter estimation has always been a big problem. To determine the available energy stored in a battery, it is necessary to know the current state-of-charge (SOC) and the capacity of the battery. For the determination of the battery SOC and capacity, it is generally estimated according to the Electromotive Force (EMF) of the battery, which is the open-circuit-voltage (OCV) of the battery in a stable state. An off-line battery SOC and capacity estimation method for lithium-ion batteries is proposed in this paper. The BP neural network with a high accuracy is trained in the case of sufficient data with the new neural network intelligent algorithm, and the OCV can be accurately predicted in a short time. The model training requires a large amount of data, so different experiments were designed and carried out. Based on the experimental data, the feasibility of this method is verified. The results show that the neural network model can accurately predict the OCV, and the error of capacity estimation is controlled within 3%. The mentioned method was also carried out in a real vehicle by using its cloud data, and the capacity estimation can be easily realized while limiting inaccuracy to less than 5%. Full article

Aqueous organic redox flow batteries (AORFBs) are emerging energy storage technologies due to their high availability, low cost of organic compounds, and the use of eco-friendly water-based supporting electrolytes. In the present work, we demonstrate a unique phenazine-based material that shows redox reversibility in neutral, basic, and acidic conditions with the redox potentials of −0.85 V (1.0 M KOH), −0.67 V (1.0 M NaCl), −0.26 V, and 0.05 V (1.0 M H₂SO₄) vs. the Ag/AgCl reference electrode and two-electron transfer process at all pH values. High solubility of the phenazine compound in water-based electrolytes up to 1.3 M is achieved by introducing quaternary amonium-based substituents, leading to the outstanding theoretical volumetric capacity of 70 Ah L⁻¹. Laboratory redox flow batteries in neutral and acidic electrolytes presented >100 cycles of stable operation with a capacity loss of 0.25 mAh L⁻¹ and 1.29 mAh L⁻¹ per cycle, respectively. The obtained results demonstrate a material with the potential for not only fundamental understanding but also the practical application of AORFBs in the development of new-generation energy storage technologies. Full article

In the last decades of electric vehicle (EV) development, battery thermal management has become one of the remaining issues that must be appropriately handled to ensure robust EV design. Starting from researching safer and more durable battery cells that can resist thermal exposure, battery packing design has also become important to avoid thermal events causing an explosion or at least to prevent fatal loss if the explosion occurs. An optimal battery packing design can maintain the battery cell temperature at the most favorable range, i.e., 25–40 °C, with a temperature difference in each battery cell of 5 °C at the maximum, which is considered the best working temperature. The design must also consider environmental temperature and humidity effects. Many design strategies have been reported, including novel battery pack constructions, a better selection of coolant materials, and a robust battery management system. However, those endeavors are faced with the main challenges in terms of design constraints that must be fulfilled, such as material and manufacturing costs, limited available battery space and weight, and low energy consumption requirements. This work reviewed and analyzed the recent progress and current state-of-the-art in designing battery packs for superior thermal management. The narration focused on significant findings that have solved the battery thermal management design problem as well as the remaining issues and opportunities to obtain more reliable and enduring batteries for EVs. Furthermore, some recommendations for future research topics supporting the advancement of battery thermal management design were also discussed. Full article

Herein, oxygen-doped hierarchical porous carbon (OHPC) is successfully fabricated derived from industrial-waste lignin. The as-obtained OHPC is endowed with not only high specific surface area and favorable pore size distribution for accessible ion diffusion and surface charge storage, but also high surface oxygen content (10.78%) for redox pseudocapacitance contributions. With these multiple advantages, the OHCP electrode demonstrates a high specific capacitance of 258 F g⁻¹ at 0.5 A g⁻¹ based on a three-electrode configuration, with a calculated pseudocapacitance contribution up to 19%. Furthermore, the assembled symmetric supercapacitor with OHPC also delivers an extremely superior electrochemical performance with outstanding rate capability, impressive cyclic stability (97.5% capacitance retention over 10,000 times under 2 A g⁻¹), and a high energy density of 9.27 Wh kg⁻¹ at 25 W kg⁻¹. This work provides fresh insights into the high-value utilization of bio-waste lignin and promises great potential in the development of high-performance electrode materials for energy storage. Full article

The emerging nickel-rich/silicon-graphite lithium-ion technology is showing a notable increase in the specific energy, a main requirement for portable devices and electric vehicles. These applications also demand short charging times, while actual charging methods for this technology imply long time or a significant reduction in cycling life. This study analyses the factors that affect the charge behavior for 18,650 commercial nickel-rich/silicon-graphite batteries. For that, long-term cycling tests have been carried out, including electric vehicle standard tests. It can be concluded that this technology has two key issues to develop an efficient charge method: high charge rates should be avoided, mainly below 15% state of charge, and the charge should be finished at 95% of actual cell capacity. This allows that, regardless of application and cell degradation level, cells can be recharged in 2 h without a negative impact on cycling life. For faster charge applications, a new method has been developed to minimize charging time without compromising the cycle life as much as the high current manufacturer method. The proposed fast charge method has proven to be notably faster, recharging in an average 1.3 h (48% less than the high current method and 68% less than the standard method). Full article

The development of carbon materials with desirable textures and new aqueous electrolytes is the key strategy to improve the performance of supercapacitors. Herein, a deep eutectic solvent (DES) was used for in situ templating of a carbon material. A carbon material was characterized (XRD, N₂-physisorption, FTIR, SEM and EDS) and used as an electrode material for the first time in multivalent-based supercapacitors. In situ templating of carbon was performed using a novel DES, which serves as a precursor for carbon and for in situ generation of MgO. The generation of MgO and its roles in templating of carbon were discussed. Templating of carbon with MgO lead to an increase in surface area and a microporous texture. The obtained carbon was tested in multivalent-ion (Al³⁺ and Mg²⁺) electrolytes and compared with H₂SO₄. The charge-storage mechanism was investigated and elaborated. The highest specific capacitance was obtained for the Al(NO₃)₃ electrolyte, while the operating voltage follows the order: Mg(NO₃)₂ > Al(NO₃)₃ > H₂SO₄. Electrical double-layer capacitance (versus pseudocapacitance) was dominant in all investigated electrolytes. The larger operating voltage in multivalent electrolytes is a consequence of the lower fraction of free water, which suppresses hydrogen evolution (when compared with H₂SO₄). The GCD was experimentally performed on the Al(NO₃)₃ electrolyte, which showed good cyclic stability, with an energy density of 22.3 Wh kg⁻¹ at 65 W kg⁻¹. Full article

The most popular approach for smoothing renewable power generation fluctuations is to use a battery energy storage system. The lead-acid battery is one of the most used types, due to several advantages, such as its low cost. However, the precision of the model parameters is crucial to a reliable and accurate model. Therefore, determining actual battery storage model parameters is required. This paper proposes an optimal identification strategy for extracting the parameters of a lead-acid battery. The proposed identification strategy-based metaheuristic optimization algorithm is applied to a Shepherd model. The bald eagle search algorithm (BES) based identification strategy provided excellent performance in extracting the battery’s unknown parameters. As a result, the proposed identification strategy’s total voltage error has been reduced to 2.182 × 10⁻³, where the root mean square error (RMSE) between the model and the data is 6.26 × 10⁻⁵. In addition, the optimization efficiency achieved 85.32% using the BES algorithm, which approved its efficiency. Full article

In this paper, capacity fade of LiFeYPO₄/graphite commercial cells during 116 cycles under different temperatures is studied. The cells were discharged in two modes, during Drive Cycle (DrC) discharge cycles the cell was discharged with current waveform calculated for example battery electric vehicle (BEV) under WLTC 3b drive cycle conditions, whereas during Constant Current (CC) discharge cycles the cell was discharged with a constant current of the same root mean square of the current, as the WLTC 3b current waveform and with the same depth of discharge. All the cells were charged in constant current/constant voltage mode. Two fresh cells were used for each discharge mode at 25 °C and as the results were similar, only one cell per discharge mode was used at the other temperatures 5 °C and 45 °C. Furthermore, simulation P2D model of calendar and cycle life was calibrated based on experimental data. SoC floating was observed during cycling for both discharge modes, accompanied with slight increase in end discharge voltage and growth of energy efficiency. Concluding the results for 25 °C, not waveform character, but the amount of electric charge in combination with calendar aging has the most effect on the cycle life, which is also proved by the simulation. For 5 °C, the capacity fade is milder for DrC discharge cycles, but simulation results do not prove that, which would demand further investigation. The results for 45 °C are apparently dependent on a higher amount of discharged and charged electric charge and influenced by calendar life, simulated capacity fade corresponds quite well to the experiment. The best State of Health (SoH) simulation results are for temperature 45 °C, RMSE is 0.10% SoH, for the other temperatures RMSE is 0.20 and 0.93% SoH for 25 and 5 °C, respectively. Full article

Graphite felts act as electrodes in VRFBs thanks to their properties such as chemical strength and electrical conductivity or 3D-structure. However, there are significant drawbacks to be overcome, such as their low wettability, sluggish kinetic reversibility and electroactivity towards faradaic processes related to vanadium electroactive species. As a consequence, it is key to alter the fibres to enhance their electrochemical performance during battery operation. Most of the previously reported modifications have been focused on incorporating surface oxygenated functional groups, even though the role of those groups on the electrocatalytic activity towards vanadium faradaic processes is still not clear. Aiming to gain knowledge on this issue, this work investigates the influence of electro-oxidation and electro-reduction treatments, performed in different acidic media (H₂SO₄ or HNO₃ solutions), on their subsequent electrochemical response towards VO²⁺/VO₂⁺ and V³⁺/V²⁺ faradaic processes. The chemical and electrochemical properties of the modified felts were analyzed to understand two key parameters that affect the vanadium reaction catalysis: the depth and oxidation degree of the fibres. A treatment with HNO₃, a strong oxidizing agent, leads to a deep oxidation of the fibre and the development of a high density of oxygenated functional groups, mainly C=O, which hinder the redox reactions of vanadium, especially for the faradaic reactions from the catholyte. Full article

The Peukert equation is widely used in various analytical models of lithium-ion batteries. However, the classical Peukert equation is applicable to lithium-ion batteries only in a limited range of discharge currents. Additionally, it does not take into account the temperature impact on a battery’s released capacity. In this paper, the applicability of the generalized Peukert equation C = C_m/(1 + (i/i₀)ⁿ) is investigated for the residual capacity determination of lithium-ion batteries based on the Hausmann model. It is proved that all the parameters (C_m, i₀, and n) of this equation depend on a battery’s temperature. That is why, for a battery-released capacity calculation, it is necessary to take into account the battery’s temperature. The equations are found to describe the temperature dependence of all the parameters of the generalized Peukert equation. The physical meaning of all the parameters is established and it is shown that the generalized Peukert equation obtained with temperature consideration is applicable to any current and temperature of a battery. Full article

PV and battery systems have been widely deployed in residential applications due to increasing environmental concerns and fossil energy prices. Energy management strategies play an important role in reducing energy bills and maximize profits. This paper first reviews the state of energy management problems, including commonly used objectives, constraints, and solutions for PV and battery applications. Then, a comparative study of different energy management strategies is conducted based on a real applied product and household profile. Moreover, results are discussed, and suggestions are given for different scenarios. Finally, conclusions and insights into future directions are also provided. Full article

The purpose of this paper is to develop a photovoltaic module array with an energy storage system that has equalizing charge/discharge controls for regulating the power supply to the grid. Firstly, the boost converter is used in conjunction with maximum power point tracking (MPPT) such that the photovoltaic module array (PVMA) can output maximum power at any time. The battery equalizing charge/discharge architecture is composed of multiple sets of bidirectional buck–boost soft-switching converters in serial connection in order to achieve zero-voltage switching (ZVS) and zero-current switching (ZCS) so that when the charge/discharge power is above 150 W, the converter efficiency can be increased by 3%. The voltage and current signals from the battery are captured and input into the digital signal processor (DSP) to establish an equalizing charge/discharge control rule. For the output voltage control of the bidirectional buck–boost soft-switching converter, the dynamic mode is derived by first using the step response at chosen operating point, then quantitatively designing the controller parameters for the converter, so that the output voltage response can meet the pre-defined performance specifications. Finally, actual test results prove that the equalizing charge/discharge time of the quantitative design controller is shortened by more than 10% when compared to the traditional proportional-integral (P-I) controller regardless of charging or discharging; this also proves that the design of the photovoltaic module array with an energy storage system (ESS) that has equalizing charge/discharge controls is valid. Full article

The filling with electrolyte and the subsequent wetting of the electrodes is a quality-critical and time-intensive process in the manufacturing of lithium-ion batteries. The exact processes involved in the wetting are still under investigation due to their poor accessibility. The accurate replication of the wetting phenomena in porous media can be demonstrated in other research fields by lattice Boltzmann simulations. Therefore, this paper deals with the comparison of experimental wetting and the simulative investigation of the wetting processes of lithium-ion battery materials by a lattice Boltzmann simulation. Particular attention is paid to the interfaces between the battery materials. These effects are relevant for a simulation of the wetting properties at the cell level. The experimental results show a 43% faster wetting of the interface between an anode and a separator than with only an anode. Overall, the simulation results show a qualitatively successful reproduction of the experimental wetting phenomena. In addition, the steps for a more precise simulation and the development of the Digital Twin are shown. This extension enables simulations of the electrolyte wetting phenomena in manufacturing lithium-ion batteries and the quantification of the wetting times. Full article

The hydrogen–bromine redox flow battery is a promising energy storage technology with the potential for capital costs as low as 220 $ kWh⁻¹ and high operational power densities in excess of 1.4 W cm⁻². In this work, enhanced surface area bromine electrodes incorporating carbon black (CB) and graphene nanoplatelets (GnPs) on carbon paper and carbon cloth substrates were investigated, and the effect of electrolyte concentration on performance of the electrodes was studied. Carbon-black-modified electrodes are found to possess the largest electrochemically active surface areas, i.e., up to 11 times that of unmodified materials, while GnP electrodes are shown to have superior kinetic activity towards the bromine electrode reaction. In terms of performance, lower electrolyte concentrations are found to favour the improved kinetic parameters associated with graphene nanoplatelet electrodes, while highly concentrated electrolytes favour the larger electrochemically active surface area of carbon black electrodes. The optimal performance was achieved on a carbon-black-modified carbon cloth electrode in a 6 M HBr/2 M Br₂ electrolyte concentration, with polarisation current densities approaching 1.6 A cm⁻² at overpotentials of ±400 mV, and mean overpotentials of 364 mV during oxidation and 343 mV during reduction, resulting from bromine oxidation/reduction cycling tests at ±1.5 A cm⁻². Full article

This paper investigates the anticipated benefits from the introduction of a battery energy storage system (BESS) behind-the-meter (BtM) of a wind farm (WF) located in a small non-interconnected island (NII) system. Contrary to the standard storage deployment applications for NII, where storage is either installed in front of the meter as a system asset or integrated into a virtual power plant with renewable energy sources, the BESS of this paper is utilized to manage the power injection constraints imposed on the WF, aiming to minimize wind energy curtailments and improve WF’s yield. A mixed integer linear programming generation scheduling model is used to simulate the operation of the system and determine the permissible wind energy absorption margin. Then, a self-dispatch algorithm is employed for the operation of the WF–BESS facility, using the BESS to manage excess wind generation that cannot be directly delivered to the grid. Additionally, the contribution of BESS to the capacity adequacy of the NII system is investigated using a Monte Carlo-based probabilistic model, amended appropriately to incorporate storage. Finally, an economic feasibility analysis is carried out, considering the possible revenue streams. By examining several BESS configurations, it has been shown that BtM BESS reduces energy curtailments and contributes substantially to resource adequacy as its energy capacity increases. However, the investment feasibility is only ensured if the capacity value of the BtM storage is properly monetized or additional dependability of wind production is claimed on the ground that the inherent intermittency of the wind production is mitigated owing to storage. Full article

For retired automotive lithium-ion batteries, state of health (SoH) is currently utilised to grade them for a second-life application. However, researchers previously challenged this and expressed that, in addition to SoH, the actual degradation mechanism, also known as degradation mode (DM), should be considered for grading, for efficient second-life operation. To date, there is little evidence to support this. A validated DM detection technique for cell/module grading does not exist. A modified DM detection technique by tracking and indexing the incremental capacity (IC) curves was previously proposed by the authors; nevertheless, it was difficult to validate. Researchers previously proposed DM identification using Electrochemical Impedance Spectroscopy (EIS) and Differential Voltage (DV) analysis. With a direct comparison of the techniques made exploiting IC, DV, and EIS, a correlation can be made, which is presented in this article. The correlation suggests that cells identified as having the same (or different) DM by the proposed technique also identified as having the same (or different) DM growth by EIS technique proposed by other researchers. Likewise, DV analysis suggests that the DV peak’s standard deviation of similar DM cells is smaller than that of the different DM cells. Full article

To enhance the stability and capacity of discharge in a solid-state battery system, we created a design that uses the same carbonate-based copolymer for a solid polymer electrolyte (SPE) and a polymer binder in a cathode. Here, we report on the crosslinked copolymer at different mol% of the allyl side group and the obtained crosslinked copolymer at 4.0 mol% (CP1) and 7.7 mol% (CP2) of the allyl side group, which were characterized by using NMR, TG/DTA, DSC, and a tensile test. The results show that CP1 and CP2 had better mechanical and thermal properties than the carbonate polymer. The superior thermal resistance behavior and good mechanical properties of the crosslinked carbonate-based copolymer were confirmed and were promising under high temperatures and longer cycles than the original copolymer electrolyte at the same salt concentration of 80 mol%. The results reveal that the addition of a crosslinked carbonate-based copolymer for the binder increased the discharge capacity by as much as 140 mAh g⁻¹ because of the reduced resistance, which was confirmed by electrochemical impedance spectroscopy (EIS), while the PVDF binder at 100% of the cathode provided a change of only 107 mAh g⁻¹. This research shows that using the same polymer for a binder and an SPE as a homogenous system can potentially improve a battery’s performance. Full article

Due to the advantages of rich resources, low cost, high energy conversion efficiency, long cycle life, and low maintenance fee, sodium–ion batteries have been regarded as a promising energy storage technology. However, their relatively low energy density compared with the commercialized lithium–ion batteries still impedes their application for power systems. Anode–free rechargeable sodium–metal batteries (AFSMBs) pose a solution to boost energy density and tackle the safety problems of metal batteries. At present, researchers still lack a comprehensive understanding of the anode-free cells in terms of electrolytes, solid–electrolyte interphase (SEI), and current collectors. This review is devoted to the field of AFSMBs, and outlines the breakthroughs that have been accomplished along with our perspective on the direction of future development for AFSMBs and the areas that warrant further investigation. Full article

The formation and evolution of the solid electrolyte interphase (SEI) layer as a function of electrolyte and electrolyte additives has been extensively studied on simple and model pure Si thin film or Si nanowire electrodes inversely to complex composite Si-based electrodes with binders and/or conductive carbon. It has been recently demonstrated that a binder-free Si@C-network electrode had superior electrochemical properties to the Si electrode with a xanthan gum binder (Si-XG-AB), which can be principally related to a reductive decomposition of electrolytes and formation of an SEI layer. Thus, here, the Si@C-network and Si-XG-AB electrodes have been used to elucidate the mechanism of SEI formation and evolution on Si-based electrodes with and without binder induced by lithiation and delithiation applying surface analytical techniques. The X-ray photoelectron spectroscopy and time-of-flight ion mass spectrometry results demonstrate that the SEI layer formed on the surface of the Si-XG-AB electrode during the discharge partially decomposes during the subsequent charging process, which results in a less stable SEI layer. Contrarily, on the surface of the Si@C-network electrode, the SEI shows less significant decomposition during the cycle, demonstrating its stability. For the Si@C-network electrode, initially, the inorganic and organic species are formed on the surface of the carbon shell and the silicon surface, respectively. These two parts of species in the SEI layer gradually grow and then fuse when the electrode is fully discharged. The behavior of the SEI layer on both electrodes corroborates with the electrochemical results. Full article

The ever-increasing characteristics of microcomputers, sensors, actuators, and communication systems require more powerful and more compact autonomous power sources. Al/bromate and Al/iodate flow batteries are proposed as new power supply units for use in oxygen-deficient environments. The batteries employ a mechanically rechargeable aluminum anode flooded with aqueous salt electrolytes or seawater, a cation-exchange membrane, and a carbonaceous porous cathode, where acidified alkali metal bromate, or iodate, is reduced in a six-electron process. The theoretical energy density of an Al/bromate flow cell per reactants is 0.65 kWh kg⁻¹. Seawater is assumed as an electrolyte for the anode compartment. Using a H₂/iodate flow cell, it is shown that iodate–iodine–iodide electrochemical transformations can be realized in both directions in acidic media at carbonaceous electrodes. At 30 °C, the area-specific power of the single cells of the Al/bromate and Al/iodate flow batteries reaches 0.26 W cm⁻² and 0.075 W cm⁻², respectively. Full article

This paper presents and parameterizes an equivalent circuit model of an all-solid-state lithium-sulfur battery cell, filling a gap in the literature associated with low computational intensity models suitable for embedded battery management applications. The paper addresses this gap by parameterizing a three-state equivalent circuit model using experimental pulse power characterization data from a laboratory-fabricated lithium-sulfur cell. The cell is mechanically loaded during electrical cycling to achieve maximum ionic conductivity and consistent capacity. A nested combination of linear and nonlinear least squares regression is used to estimate the model parameters. The model captures slow cycling and fast pulse charge/discharge dynamics within 34 mV RMS error. The series resistance changes significantly at high/low states of charge and low C-rates. A sensitivity analysis determines that accurately modeling the dependence of resistance on C-rate and state of charge is important for model fidelity. Full article

Since the Young’s modulus of the separator is weaker than that of the other materials inside a lithium-ion battery, local deformation may cause blockage or rupture of the separator, resulting in internal short-circuit or other disasters. This study collects the stress–strain relationship of various materials within the battery, and combines the mechanical model with the electrochemical model through the coupled relationship between the volumetric strain and the volume fractions of solid and liquid phases. From a two-dimensional electrochemical simulation of a spherical indentation on a layer-structured battery, it is found that there is local negative value of the side reaction overpotential on the negative electrode adjacent to the separator after the battery is deformed. A higher strain will cause a decrease in the negative overpotential, leading to a more serious deposition of lithium during the charge process. The deformation-dependent overpotential is evaluated and the lithium deposition is then quantified. Moreover, the issue of the separator thickness is explored. We find that under an indentation, the thickness does not affect the charging voltage, while a thinner layer will reduce the separator porosity and thus lower the overpotential and increase the chance of lithium deposition. Full article

Rechargeable aqueous Zn/MnO₂ batteries are very potential for large-scale energy storage applications owing to their low cost, inherent safety, and high theoretical capacity. However, the MnO₂ cathode delivers unsatisfactory cycling performance owing to its low intrinsic electronic conductivity and dissolution issue. Herein, we design and synthesize a Ag-doped sea-urchin-like MnO₂ material for rechargeable zinc-ion batteries (ZIBs). Doping Ag was found to reduce charge transfer resistance, increase the redox activity, and improve the cycling stability of MnO₂. The unique sea-urchin-like structure maintains rich active sites for charge storage. As a result, the Ag-doped MnO₂-based ZIB presents a high reversible specific capacity to 315 mA h g⁻¹ at 50 mA g⁻¹, excellent rate performance, and a capacity retention of 94.4% when cycling over 500 cycles. An ex situ TEM test demonstrates the low-dissolution property of Ag-doped MnO₂. A flexible quasi-solid-state ZIB is successfully assembled using Ag-doped MnO₂ on graphite paper, which shows a stable specific capacity of 171 mA h g⁻¹ at 1 A g⁻¹ when cycled over 600 cycles. Our investigation demonstrates the significant role played by Ag doping in enhancing the ZIB performance of MnO₂, and gives some insight into developing advanced active materials by heteroatom doping. Full article

The prediction of the degradation of lithium-ion batteries is essential for various applications and optimized recycling schemes. In order to address this issue, this study aims to predict the cycle lives of lithium-ion batteries using only data from early cycles. To reach such an objective, experimental raw data for 121 commercial lithium iron phosphate/graphite cells are gathered from the literature. The data are analyzed, and suitable input features are generated for the use of different machine learning algorithms. A final accuracy of 99.81% for the cycle life is obtained with an extremely randomized trees model. This work shows that data-driven models are able to successfully predict the lifetimes of batteries using only early-cycle data. That aside, a considerable reduction in errors is seen by incorporating data management and physical and chemical understanding into the analysis. Full article

Biopolymers are promising materials as electrolytes with high flexibility, good performance, cost effectiveness, high compatibility with solvents, and film-forming ability. Chitosan (CS) and carboxymethylcellulose (CMC) can form an intermolecular complex, giving rise to hydrogels capable of absorbing ionic solutions. Citric acid (CA) is an effective biological chemical crosslinker that assists the formation of amide and ester bonds between CMC and CS, resulting in a structure with high ionic conductivity and good structural integrity. In this study, a chemical crosslinking strategy is used to synthesize electrolyte hydrogels for zinc–air batteries. The effects of crosslinking are studied on the structural and electrochemical performance of the membranes. The results show an improvement in the ionic conductivity with respect to the homologous electrolyte hydrogel systems reported, with a maximum of 0.19 S∙cm⁻¹ at 30 °C. In addition, the cyclic voltammetry studies showed a current intensity increase at higher CA content, reaching values of 360 mA∙cm⁻². Structural characterization suggests a higher thermal stability and a decrease in the degree of crystallinity caused by the polymers’ crosslinking. Finally, these membranes were tested in Zn–air batteries, obtaining power densities of 85 mW∙cm⁻². The proposed hydrogels show to be appropriate for energy zinc–air battery applications and present an alternative to support the sustainable energy transition. Full article

Short-circuit induced thermal runaway is one of the main obstacles that hinder the large-scale commercial applications of lithium metal batteries. The fast and accurate detection of an internal short-circuit is, therefore, a key step for preventing thermal runaway. The traditional temperature detection is mainly to place temperature sensors outside the battery, which is far from the actual hotspot inside the cell and has a lag in response. In this study, we integrated arrays of micro resistance temperature detectors (AMRTDs) inside the pouch cell. AMRTDs can be used for the detection of a short-circuit with a high temporal and spatial resolution. We show that the initial short-circuit may induce a high temperature local hotspot exceeding 300 °C, whereas the nearby area was still maintained at near room temperature. Our work provides a design strategy for in-situ detection of short-circuits in lithium metal batteries. Full article