Batteries, Volume 10, Issue 1 (January 2024) – 39 articles

The pursuit of industrializing lithium-ion batteries (LIBs) with exceptional energy density and top-tier safety features presents a substantial growth opportunity. The demand for energy storage is steadily rising, driven primarily by the growth in electric vehicles and the need for stationary energy storage systems. However, the manufacturing process of LIBs, which is crucial for these applications, still faces significant challenges in terms of both financial and environmental impacts. Our review paper comprehensively examines the dry battery electrode technology used in LIBs, which implies the use of no solvents to produce dry electrodes or coatings. In contrast, the conventional wet electrode technique includes processes for solvent recovery/drying and the mixing of solvents like N-methyl pyrrolidine (NMP). Methods that use dry films bypass the need for solvent blending and solvent evaporation processes. The advantages of dry processes include a shorter production time, reduced energy consumption, and lower equipment investment. This is because no solvent mixing or drying is required, making the production process much faster and, thus, decreasing the price. This review explores three solvent-free dry film techniques, such as extrusion, binder fibrillation, and dry spraying deposition, applied to LIB electrode coatings. Emphasizing cost-effective large-scale production, the critical methods identified are hot melting, extrusion, and binder fibrillation. This review provides a comprehensive examination of the solvent-free dry-film-making methods, detailing the underlying principles, procedures, and relevant parameters. Full article

Lithium-ion batteries (LIBs) are a widely used energy storage technology as they possess high energy density and are characterized by the reversible intercalation/deintercalation of Li ions between electrodes. The rapid development of LIBs has led to increased production efficiency and lower costs for manufacturers, resulting in a growing demand for batteries and their application across various industries, particularly in different types of vehicles. In order to meet the demand for LIBs while minimizing climate-impacting emissions, the reuse, recycling, and repurposing of LIBs is a critical step toward achieving a sustainable battery economy. This paper provides a comprehensive review of lithium-ion battery recycling, covering topics such as current recycling technologies, technological advancements, policy gaps, design strategies, funding for pilot projects, and a comprehensive strategy for battery recycling. Additionally, this paper emphasizes the challenges associated with developing LIB recycling and the opportunities arising from these challenges, such as the potential for innovation and the creation of a more sustainable and circular economy. The environmental implications of LIB recycling are also evaluated with methodologies able to provide a sustainability analysis of the selected technology. This paper aims to enhance the comprehension of these trade-offs and encourage discussion on determining the “best” recycling route when targets are in conflict. Full article

The ongoing transition toward electric vehicles is a major factor in the exponential rise in demand for lithium-ion batteries (LIBs). There is a significant effort to recycle battery materials to support the mining industry in ensuring enough raw materials and avoiding supply disruptions, so that there will be enough raw materials to produce LIBs. Nevertheless, LIBs that have reached the end of their useful lives and are sent for recycling may still have some energy left in them, which could be dangerous during handling and processing. Therefore, it is important to conduct discharge pretreatment of LIBs before dismantling and crushing them, especially in cases where pyrometallurgical recycling is not used. Electrochemical discharge in conducting solutions has been commonly studied and implemented for this purpose, but its effectiveness has yet to be fully validated. Non-electrochemical discharge has also been researched as a potentially cleaner and more efficient discharge technology at the same time. This article presents a non-electrochemical discharge process by completely draining the energy from used batteries before recycling. A comprehensive investigation of the behavior of LIBs during discharge and the amount of energy remaining after fully discharging the battery at different temperatures is analyzed in this work. According to the experimental findings, completely discharging the battery at higher temperatures results in a reduced amount of residual energy in the battery. This outcome holds great importance in terms of safe and environmentally friendly recycling of used LIBs, emphasizing that safety and environmentally friendly recycling must go hand in hand with a cost-effective and sustainable solution. Full article

In an effort to tackle climate change, various sectors, including the transport sector, are turning towards increased electrification. As a result, there has been a swift increase in the sales of electric vehicles (EVs) that use lithium-ion batteries (LIBs). When LIBs reach their end of life in EVs, it may still be possible to use them in other, less demanding applications, giving them a second life. This article describes a case study where the feasibility of a hypothetical business repurposing Tesla Model S/X batteries in the Ostrobothnia region, Finland, is investigated. A material-flow analysis is conducted to estimate the number of batteries becoming available for second-life applications from both the Ostrobothnia region and Finland up to 2035. The cost of repurposing batteries is evaluated for four different scenarios, with the batteries being processed either on the pack, module, or cell level. Three scenarios were found to be feasible, with repurposing costs of 27.2–38.3 EUR/kWh. The last scenario, in which all battery packs are disassembled at the cell level, was found not to be feasible due to the labor intensiveness of disassembly and testing at the cell level. This work gives indications of the potential for repurposing batteries in the Ostrobothnia region and Finland. Full article

Cost-effective bismuth (Bi) boasts a high theoretical capacity and exceptional selectivity towards Cl^- ion storage, making it a promising material for desalination batteries (DBs). However, the substantial volume expansion and low conductivity severely hinder the cycling performance of Bi-based DBs. In this study, a carbon-layer-coated Bi nanocomposite (Bi@C) was synthesized by pyrolyzing a metal–organic framework (Bi-MOF) containing Bi using a straightforward method. The results show that the Bi@C synthesized under the condition of annealing at 700 °C for 2 h has the optimum properties. The Bi@C has good multiplication performance, and the desalination capacity is 106.1 mg/g at a high current density of 1000 mA/g. And the material exhibited a high desalination capacity of 141.9 mg/g at a current density of 500 mA/g and retained 66.9% of its capacity after 200 cycles. In addition, the Bi@C can operate at a wide range of NaCl concentrations from 0.05 to 2 mol/L. The desalination mechanism analysis of the Bi@C revealed that the carbon coating provides space for Bi particles to expand in volume, thereby mitigating the issues of electrode material powdering and shedding. Meanwhile, the porous carbon skeleton establishes electron and ion channels to enhance the electrode material’s conductivity. This research offers a promising strategy for the application of chloride-storage electrode materials in electrochemical desalination systems. Full article

Lithium-ion batteries have revolutionized the portable and stationary energy industry and are finding widespread application in sectors such as automotive, consumer electronics, renewable energy, and many others. However, their efficiency and longevity are closely tied to accurately measuring their SOC and state of health (SOH). The need for precise algorithms to estimate SOC and SOH has become increasingly critical in light of the widespread adoption of lithium-ion batteries in industrial and automotive applications. While the benefits of lithium-ion batteries are undeniable, the challenges related to their efficient and safe management cannot be overlooked. Accurate estimation of SOC and SOH is crucial for ensuring optimal battery management, maximizing battery lifespan, optimizing performance, and preventing sudden failures. Consequently, research and development of reliable algorithms for estimating SOC and SOH have become an area of growing interest for the scientific and industrial community. This review article aims to provide an in-depth analysis of the state-of-the-art in SOC and SOH estimation algorithms for lithium-ion batteries. The most recent and promising theoretical and practical techniques used to address the challenges of accurate SOC and SOH estimation will be examined and evaluated. Additionally, critical evaluation of different approaches will be highlighted: emphasizing the advantages, limitations, and potential areas for improvement. The goal is to provide a clear view of the current landscape and to identify possible future directions for research and development in this crucial field for technological innovation. Full article

The large-scale adoption of electric vehicles will require a charging infrastructure that meets the new needs that will arise. Currently, the charging infrastructure for electric vehicles is still in the early stages of development, not least because of the low number of electric vehicles in use. However, there are still many questions to be answered when it comes to standardization in terms of connectors, DC or AC charging, and power, as well as both operational and economic issues. Although this topic has been the subject of numerous studies over the last ten years, there are still gaps to be filled, particularly with regard to the mix of different recharging strategies (normal, accelerated, fast, induction-track, etc.), as well as the economic and operational aspects. Moreover, the relationship between users and private cars is changing rapidly, and charging behaviors are not yet well established. Full article

This paper introduces a novel hybrid thermal management strategy, which uses secondary coolants (air and fluid) to extract heat from a phase change material (paraffin), resulting in an increase in the phase change material’s heat extraction capability and the battery module’s overall thermal performance. A novel cold plate design is developed and placed between the rows and columns of the cells. The cold plate contains a single fluid body to improve the thermal performance of the battery module. Experimental studies were conducted to obtain the temperature and heat flux profiles of the battery module. Moreover, a numerical model is developed and validated using the experimental data obtained. The numerical data stayed within ±2% of the experimental data. In addition, the ability of nanoparticles to increase the thermal conductivity of water is examined and it is found that the cooling from the liquid cooling component is not sensitive enough to capture the 0.32 W/m K increase in the thermal conductivity of the fluid. Furthermore, in order to enhance the air cooling, fins were added within the air duct to the cold plate. However, this is not feasible, as the pressure drop through the addition of the fins increased by ~245%, whereas the maximum temperature of the battery module reduced by only 0.6 K. Finally, when scaled up to an entire battery pack at a high discharge rate of 7 C, the numerical results showed that the overall temperature uniformity across the pack was 1.14 K, with a maximum temperature of 302.6 K, which was within the optimal operating temperature and uniformity ranges. Therefore, the developed thermal management strategy eliminates the requirement of a pump and reservoir and can be scaled up or down according to the energy and power requirements. Full article

This paper addresses the challenge of thermal runaway propagation in lithium-ion battery modules and presents a safety protection design method based on a thermal propagation model. Firstly, it systematically analyzes the triggering mechanisms of thermal runaway in batteries, establishes a model for cell thermal runaway, and calibrates the model parameters through experiments. Secondly, by integrating the cell thermal runaway model and considering the three-dimensional structure of the battery module, a comprehensive thermal runaway propagation model is developed and validated. Subsequently, a simulation study on thermal runaway propagation, incorporating multi-factor influences and typical operating conditions, is conducted using the established thermal propagation model for the battery module. The study elucidates the thermal runaway propagation characteristics of the battery module under different safety protection strategies. The findings highlight that the proposed safety protection strategy effectively mitigates thermal propagation within the battery module, particularly when the thermal runaway is influenced by multiple factors. Full article

The problem of lithium dendrite growth has persistently hindered the advancement of lithium metal batteries. Lithium phosphorus oxynitride (LiPON), functioning as an amorphous solid electrolyte, is extensively employed as an artificial solid electrolyte interphase (SEI) owing to its remarkable stability and mechanical strength, which is beneficial for effectively mitigating dendrite growth. Nevertheless, the significant challenge arises from the volume changes in the Li metal anode during cycling, leading to the vulnerability of LiPON due to its high rigidity, which impedes the widespread use of LiPON. To address this problem, our study introduces a lithium-boron (Li-B) alloy as the anode, featuring a 3D structure, which can be synergistic with the artificial LiPON layer during cycling, leading to a better performance. The average Coulombic efficiency (CE) of a Li || Cu half-cell reaches 95% over 120 cycles. The symmetric cells exhibit sustained operation for 950 h with a low voltage polarization of less than 20 mV under a current density of 0.5 mA/cm² and for 410 h under 1 mA/cm². Full article

The primary goal of this review is to provide a comprehensive overview of the state-of-the-art in solid-state batteries (SSBs), with a focus on recent advancements in solid electrolytes and anodes. The paper begins with a background on the evolution from liquid electrolyte lithium-ion batteries to advanced SSBs, highlighting their enhanced safety and energy density. It addresses the increasing demand for efficient, safe energy storage in applications like electric vehicles and portable electronics. A major part of the paper analyzes solid electrolytes, key to SSB technology. It classifies solid electrolytes as polymer-based, oxide-based, and sulfide-based, discussing their distinct properties and application suitability. The review also covers advancements in anode materials for SSBs, exploring materials like lithium metal, silicon, and intermetallic compounds, focusing on their capacity, durability, and compatibility with solid electrolytes. It addresses challenges in integrating these anode materials, like the interface stability and lithium dendrite growth. This review includes a discussion on the latest analytical techniques, experimental studies, and computational models to understand and improve the anode–solid electrolyte interface. These are crucial for tackling interfacial resistance and ensuring SSBs’ long-term stability and efficiency. Concluding, the paper suggests future research and development directions, highlighting SSBs’ potential in revolutionizing energy storage technologies. This review serves as a vital resource for academics, researchers, and industry professionals in advanced battery technology development. It offers a detailed overview of materials and technologies shaping SSBs’ future, providing insights into current challenges and potential solutions in this rapidly evolving field. Full article

The selective separation of lithium from spent ternary positive materials is achieved through hydrogen reduction followed by water leaching. Almost 98% of the Li is transformed into soluble LiOH⋅H₂O, while the Ni, Co and Mn species are all transformed into insoluble metals or their oxides, so the recovery of Ni, Co and Mn at this stage is challenging. The traditional acid leaching process has drawbacks such as high oxidant consumption, the low recovery of valuable metals and high production costs. Thus, sulfation roasting followed by water leaching was studied in this project. The leaching levels of Ni, Co, Mn and Al reached 87.13%, 99.87%, 96.21% and 94.95%, respectively, with 1.4 times the theoretical amount of sulfuric acid used at 180 °C for 120 min. To avoid the adverse effects of Mn and Al on the quality of the Ni and Co sulfate products, Mn²⁺ was first separated and precipitated via the KMnO₄ oxidation–precipitation method, and >98% of the Mn was removed and precipitated within 30 min with a K_p/K_t (ratio of actual usage to theoretical usage of KMnO₄) of 1.0 at pH = 2.0 and 25 °C. After removal of the Mn, the solvent extraction method was adopted by using P204 as an extractant to separate Al. More than 98% of the Al was extracted in 30 min with 20% (v/v) P204 + 10% (v/v) TBP with an A/O ratio of 1:1 at 30 °C. This optimized process for extracting lithium residues improved the hydrogen reduction process of waste lithium batteries and will enable industrialization of the developed processes. Full article

Lithium-ion batteries (LIBs) can play a crucial role in the decarbonization process that is being tackled worldwide; millions of electric vehicles are already provided with or are directly powered by LIBs, and a large number of them will flood the markets within the next 8–10 years. Proper disposal strategies are required, and sustainable and environmental impacts need to be considered. Despite still finding little applicability in the industrial field, recycling could become one of the most sustainable options to handle the end of life of LIBs. This review reports on the most recent advances in sustainable processing for spent LIB recycling that is needed to improve the LIB value chain, with a special focus on green leaching technologies for Co-based cathodes. Specifically, we provide the main state of the art for sustainable LIB recycling processes, focusing on the pretreatment of spent LIBs; we report on Life Cycle Assessment (LCA) studies on the usage of acids, including mineral as well as organic ones; and summarize the recent innovation for the green recovery of valuable metals from spent LIBs, including electrochemical methods. The advantage of using green leaching agents, such as organic acids, which represent a valuable option towards more sustainable recycling processes, is also discussed. Organic acids can, indeed, reduce the economic, chemical, and environmental impacts of LIBs since post-treatments are avoided. Furthermore, existing challenges are identified herein, and suggestions for improving the effectiveness of recycling are defined. Full article

The health assessment of lithium-ion batteries holds great research significance in various areas such as battery management systems, battery usage and maintenance, and battery economic evaluation. However, because environmental perturbations are not taken into account during the assessment, the accuracy and reliability of the assessment are limited. Thus, a health assessment model for lithium-ion batteries based on evidence reasoning rules with dynamic reference value (ER-DRV) is proposed in this paper. Firstly, considering that the data are subject to changes, dynamic reference values, real-time weights, and real-time reliability were utilized in the model to ensure the effectiveness and accuracy of the assessment. Moreover, an enhanced optimization method based on the whale optimization algorithm (WOA) was developed to improve the accuracy of the assessment model. In addition, the robustness of the ER-DRV model was studied with perturbation analysis methods. Finally, the proposed method was validated on two open lithium-ion battery datasets. The experimental results show that the health assessment method proposed in this article not only has higher accuracy and transparent reasoning process but also has strong robustness and good generalization ability. Full article

Recently, potassium-ion batteries (KIBs) have attracted significant interest due to a number of factors, including the growing demand for energy and limited lithium resources. However, their practical use is hampered by poor cycling stability due to the large size of K⁺. Therefore, it is critical to develop a structural design that effectively suppresses large volume changes. This study presents a simple method of using a salt template to fabricate porous microspheres (p-MoSe₂@C MS) of MoSe₂ and a carbon matrix as anode materials in KIBs. These microspheres have a distinct porous design, with uniformly distributed MoSe₂ nanocrystals embedded in the carbon matrix to prevent MoSe₂ overgrowth due to material diffusion during heat treatment. The manufacturing process combined one-step spray drying with recyclable NaCl as a hard template. Through a two-step thermal process under an inert atmosphere, the initial dextrin, NaCl, and Mo salt microspheres were converted into a p-MoSe₂@N MS composite. The carbon structure derived from the dextrin maintained the shape of the microspheres when NaCl was removed, ensuring no overgrowth of MoSe₂. This well-designed porous structure improves the interaction with the electrolyte, facilitating the transport of ions and electrons and reducing the K⁺ diffusion distances. In addition, the porous carbon structure accommodates large volume changes during cycling and maintains its structural strength. As a result, p-MoSe₂@C MS composite exhibits superior electrochemical properties, with remarkable capacity, long-term cycling stability (193 mA h g⁻¹ after 500 cycles at 2.0 A g⁻¹), and rate capability. Full article

This review focuses on the promising technology of solid-state batteries (SSBs) that utilize lithium metal and solid electrolytes. SSBs offer significant advantages in terms of high energy density and enhanced safety. This review categorizes solid electrolytes into four classes: polymer, oxide, hybrid, and sulfide solid electrolytes. Each class has its own unique characteristics and benefits. By exploring these different classes, this review aims to shed light on the diversity of materials and their contributions to the advancement of SSB technology. In order to gain insights into the latest technological developments and identify potential avenues for accelerating the progress of SSBs, this review examines the intellectual property landscape related to solid electrolytes. Thus, this review focuses on the recent SSB technology patent filed by the main companies in this area, chosen based on their contribution and influence in the field of batteries. The analysis of the patent application was performed through the Espacenet database. The number of patents related to SSBs from Toyota, Samsung, and LG is very important; they represent more than 3400 patents, the equivalent of 2/3 of the world’s patent production in the field of SSBs. In addition to focusing on these three famous companies, we also focused on 15 other companies by analyzing a hundred patents. The objective of this review is to provide a comprehensive overview of the strategies employed by various companies in the field of solid-state battery technologies, bridging the gap between applied and academic research. Some of the technologies presented in this review have already been commercialized and, certainly, an acceleration in SSB industrialization will be seen in the years to come. Full article

This article explores the novel application of a trained artificial neural network (ANN) in the prediction of vanadium redox flow battery behaviour and compares its performance with that of a two-dimensional numerical model. The aim is to evaluate the capability of two ANNs, one for predicting the cell potential and one for the overpotential under various operating conditions. The two-dimensional model, previously validated with experimental data, was used to generate data to train and test the ANNs. The results show that the first ANN precisely predicts the cell voltage under different states of charge and current density conditions in both the charge and discharge modes. The second ANN, which is responsible for the overpotential calculation, can accurately predict the overpotential across the cell domains, with the lowest confidence near high-gradient areas such as the electrode membrane and domain boundaries. Furthermore, the computational time is substantially reduced, making ANNs a suitable option for the fast understanding and optimisation of VRFBs. Full article

Zinc-ion batteries (ZIBs) are increasingly recognized as highly promising candidates for grid-scale energy storage systems due to their cost-effectiveness, environmental friendliness, and high security. Despite recent advancements in the research of cathode materials, Zn anodes, and electrolytes, several challenges persist and must be addressed, including cathode dissolution, generation of by-products, and zinc dendrite formation, which hinder the future application of ZIBs. In this review, we systematically summarize the recent developments in electrospinning technology within ZIBs. First, the principle technical parameters and subsequent thermal treatment of electrospinning technology are discussed, and then the synthetic preparation, morphologies, and electrochemical performance of electrospun nanostructured electrodes in ZIBs are comprehensively reviewed. Finally, some perspectives on research directions and optimization strategies for electrospinning technology in energy applications are outlined. Full article

Over the past years, lithium-ion solid-state batteries have demonstrated significant advancements regarding such properties as safety, long-term endurance, and energy density. Solid-state electrolytes based on lithium halides offer new opportunities due to their unique features such as a broad electrochemical stability window, high lithium-ion conductivity, and elasticity at close to melting point temperatures that could enhance lithium-ion transport at interfaces. A comparative study of lithium indium halide (Li₃InCl₆) electrolytes synthesized through a mechano-thermal method with varying optimization parameters revealed a significant effect of temperature and pressure on lithium-ion transport. An analysis of Electrochemical Impedance Spectroscopy (EIS) data within the temperature range of 25–100 °C revealed that the optimized Li₃InCl₆ electrolyte reveals high ionic conductivity, reaching 1.0 mS cm⁻¹ at room temperature. Herein, we present the utilization of in situ/operando X-ray Photoelectron Spectroscopy (XPS) and in situ X-ray powder diffraction (XRD) to investigate the temperature-dependent behavior of the Li₃InCl₆ electrolyte. Confirmed by these methods, significant changes in the Li₃InCl₆ ionic conductivity at 70 °C were observed due to phase transformation. The observed behavior provides critical information for practical applications of the Li₃InCl₆ solid-state electrolyte in a broad temperature range, contributing to the enhancement of lithium-ion solid-state batteries through their improved morphology, chemical interactions, and structural integrity. Full article

Macro-scale mechanical testing and finite element analysis of lithium metal in compression have been shown to suggest methods and parameters for producing thin lithium anodes. Consideration of engineering and geometrically corrected stress experiments shows that the increasing contact area dominates the stress increase observed during the compression, not strain hardening, of lithium. Under static loading, the lithium metal stress relaxes, which means there is a speed of deformation (engineering strainrate limit of $6.4\times {10}^{-5}$ s${}^{-1}$) where there is no increase in stress during compression. Constant displacement tests show that stress relaxation depends on the initial applied stress and the amount of athermal plastic work within the material. The finite element analysis shows that barrelling during compression and the requirement for high applied stresses to compress lithium with a small height-to-width ratio are friction and geometric effects, respectively. The outcomes of this work are discussed in relation to the diminishing returns of stack pressure, the difficulty in closing voids, and potential methods for designing and producing sub-micron lithium anodes. Full article

Predicting the core temperature of a Li-ion battery is crucial for precise state estimation, but it is difficult to directly measure. Existing quick temperature-predicting approaches can hardly consider the thermal mass of complex structure that may cause time delays, particularly under high C-rate dynamic conditions. In this paper, we developed a quick temperature prediction algorithm based on a thermal convolution method (TCM) to calculate the core temperature of a flat heat pipe-based battery thermal management system (FHP-BTMS) under dynamic conditions. The model could predict the core temperature rapidly through convolution of the thermal response map which contains full physical information. Firstly, in order to obtain a high fidelity spatio-temporal temperature distribution, the thermal capacitance-resistance network (TCRN) of the FHP-BTMS is established and validated by constant and dynamic discharging experiments. Then, the response map of the core temperature motivated by various impulse heat sources and heat sinks is obtained. Specifically, the dynamic thermal characteristics of an FHP are discussed to correct the boundary conditions of the TCM. Afterwards, the temperature prediction performances of the TCM and a lumped model under different step operating conditions are compared. The TCM results show a 70–80% accuracy improvement and better dynamic adaptivity than the lumped model. Lastly, a vertical take-off and landing (VTOL) profile is employed. The temperature prediction accuracy results show that the TCM can maintain a relative error below 5% throughout the entire prediction period. Full article

The integration of renewable resources in isolated systems can produce instability in the electrical grid due to its intermintency. In today’s microgrids, which lack synchronous generation, physical inertia is substituted for inertia emulation. To date, the most effective approach remains the frequency derivative control technique. Nevertheless, within this method, the ability to provide virtual drooping is often disregarded in its design, potentially leading to inadequate development in systems featuring high renewable penetration and low damping. To address this issue, this paper introduces an innovative design and analysis of virtual inertia control to simultaneously mimic droop and inertia characteristics in microgrids. The dynamic frequency response without and with renewable energy sources penetration is comparatively analyzed by simulation. The proposed virtual inertia control employs a derivative technique to measure the rate of change of frequency slope during inertia emulation. Sensitivity mapping is conducted to scrutinize its impact on dynamic frequency response. Finally, the physical battery storage system of the University of Cuenca microgrid is used as a case study under operating conditions. Full article

This paper presents operation and control systems for a new modular on-board charger (OBC) based on a SEPIC converter (MSOBC) for electric vehicle (EV) applications. The MSOBC aims to modularise the battery units in the energy storage system of the EV to provide better safety and improved operation. This is mainly achieved by reducing the voltage of the battery packs without sacrificing the performance required by the HV system. The proposed MSOBC is an integrated OBC which can operate the EV during traction and braking, as well as charge the battery units. The MSOBC is composed of several submodules consisting of a full-bridge voltage source converter connected on the ac side and SEPIC converter installed on the battery side. The SEPIC converter controls the battery segments with a continuous current because it has an input inductor which can smooth the battery’s currents without the need for large electrolytic capacitors. The isolated version of the SEPIC converter is employed to enhance the system’s safety by providing galvanic isolation between the batteries and the ac output side. This paper presents the necessary control loops to ensure the optimal operation of the EV with the MSOBC in terms of charge and temperature balance without disturbing the required modes of operation. The mathematical analyses in this paper are validated using a full-scale EV controlled by TMS320F28335 DSP. Full article

Transition metal sulfides have excellent electrochemical performance and show great potential for improving the energy density of asymmetric supercapacitors. This study demonstrates a two-step synthesis technique and highlights the enhanced energy storage efficiency of ZnS-NiS₂ composite materials for asymmetric supercapacitors. The composite materials of ZnS nanosheets and NiS₂ nanocrystals are characterized by a rough surface and spherical shape. The sample with the optimal ratio (ZnS-NiS₂-1:7) exhibits a maximum specific capacitance of 1467.9 F g⁻¹ (550.5 C g⁻¹) at 1 A g⁻¹. The specific capacitance of the ZnS-NiS₂-1:7 sample is 26.1% higher compared to the pure NiS₂ sample. Furthermore, the assembled ZnS-NiS₂-1:7//AC device shows a high specific capacitance of 127.8 F g⁻¹ (217.3 C g⁻¹) at 1 A g⁻¹ and an energy density of 51.3 Wh kg⁻¹ at a power density of 820.8 W kg⁻¹. The ZnS-NiS₂-1:7 sample has exceptional energy storage capability on its own, but it can also be composited with graphene to further increase the specific capacitance (1681.0 F g⁻¹ at 1 A g⁻¹), suggesting promising prospects for the ZnS-NiS₂-based composite material in the future. Full article

By virtue of the high theoretical energy density and low cost, Lithium–sulfur (Li-S) batteries have drawn widespread attention. However, their electrochemical performances are seriously plagued by the shuttling of intermediate polysulfides and the slow reaction kinetics during practical implementation. Herein, we designed a freestanding flexible membrane composed of nitrogen-doped porous carbon nanofibers anchoring iron and zinc single atoms (FeZn-PCNF), to serve as the polysulfide barrier and the reaction promotor. The flexible porous networks formed by the interwoven carbon nanofibers not only offer fast channels for the transport of electrons/ions, but also guarantee the structural stability of the all-in-one multifunctional interlayer during cycling. Highly dispersed Fe and Zn atoms in the carbon scaffold synergistically immobilize sulfur species and expedite their reversible conversion. Therefore, employing FeZn-PCNF as the freestanding interlayer between the cathode and separator, the Li-S battery delivers a superior initial reversible discharge capacity of 1140 mA h g⁻¹ at a current density of 0.5 C and retains a high capacity of 618 mA h g⁻¹ after 600 cycles at a high current density of 1 C. Full article

As global energy priorities shift toward sustainable alternatives, the need for innovative energy storage solutions becomes increasingly crucial. In this landscape, solid-state batteries (SSBs) emerge as a leading contender, offering a significant upgrade over conventional lithium-ion batteries in terms of energy density, safety, and lifespan. This review provides a thorough exploration of SSBs, with a focus on both traditional and emerging cathode materials like lithium cobalt oxide (LiCoO₂), lithium manganese oxide (LiMn₂O₄), lithium iron phosphate (LiFePO₄), as well as novel sulfides and oxides. The compatibility of these materials with solid electrolytes and their respective benefits and limitations are extensively discussed. The review delves into the structural optimization of cathode materials, covering strategies such as nanostructuring, surface coatings, and composite formulations. These are critical in addressing issues like conductivity limitations and structural vulnerabilities. We also scrutinize the essential roles of electrical and thermal properties in maintaining battery safety and performance. To conclude, our analysis highlights the revolutionary role of SSBs in the future of energy storage. While substantial advancements have been made, the path forward presents numerous challenges and research opportunities. This review not only acknowledges these challenges, but also points out the need for scalable manufacturing approaches and a deeper understanding of electrode–electrolyte interactions. It aims to steer the scientific community toward addressing these challenges and advancing the field of SSBs, thereby contributing significantly to the development of environmentally friendly energy solutions. Full article

This study presents a novel data-driven method for state-of-charge estimation in lithium-ion batteries. It integrates a temporal convolutional network with multi-verse optimization to enhance the accuracy of predicting the state of charge. The temporal convolutional network possesses advantages such as an extended memory window and efficient parallel computation, exhibiting exceptional performance in time-series tasks for state of charge estimation. Its hyperparameters are optimized by adopting multi-verse optimization to obtain better model performance. The driving model utilizes various measurable data as inputs, including battery terminal voltage, current, and surface temperature. To validate the effectiveness of the proposed method, extensive datasets from diverse dynamic working conditions at different ambient temperatures are employed for model training, validation, and testing. The numerical outcomes provide evidence of the proposed method’s superior performance compared to the other two methods, providing a more robust and accurate solution for the state of charge estimation in lithium-ion batteries. Full article

Li-ion batteries (LIBs) represent the most sophisticated electrochemical energy storage technology. Nevertheless, they still suffer from safety issues and practical drawbacks related to the use of toxic and flammable liquid electrolytes. Thus, polymer-based solid electrolytes may be a suitable option to fulfill the safety and energy density requirements, even though the lack of high ionic conductivity at 25 °C (10⁻⁸–10⁻⁷ S cm⁻¹) hinders their performance. To overcome these drawbacks, herein, we present an all-solid-state Li-metal full cell based on a three-component solid poly(ethylene oxide)/lithium bis(trifluoromethanesulfonyl) imide/titanium dioxide composite electrolyte that outclasses the conventional poly(ethylene oxide)-based solid electrolytes. Moreover, the cell features are enhanced by the combination of the solid electrolyte with a self-standing LiFePO₄ catholyte fabricated through an innovative, simple and easily scalable approach. The structural, morphological and compositional properties of this system are characterized, and the results show that the electrochemical performance of the solid composite electrolyte can be considerably improved by tuning the concentration and morphology of TiO₂. Additionally, tests performed with the self-standing LiFePO₄ catholyte underline a good cyclability of the system, thus confirming the beneficial effects provided by the novel manufacturing path used for the preparation of self-standing electrodes. Full article

Non-aqueous redox flow batteries (NARFBs) have been attracting much attention because they can significantly increase power and energy density compared to conventional RFBs. In this study, novel pore-filled anion-exchange membranes (PFAEMs) for application to a NAPFB employing metal polypyridyl complexes (i.e., Fe(bpy)₃²⁺/Fe(bpy)₃³⁺ and Co(bpy)₃²⁺/Co(bpy)₃³⁺) as the redox species are successfully developed. A porous polyethylene support with excellent solvent resistance and mechanical strength is used for membrane fabrication. The PFAEMs are prepared by filling an ionic liquid monomer containing an imidazolium group and a crosslinking agent into the pores of the support film and then performing in situ photopolymerization. As a result, the prepared membranes exhibit excellent mechanical strength and stability in a non-aqueous medium as well as high ion conductivity. In addition, a low crossover rate for redox ion species is observed for the prepared membranes because they have relatively low swelling characteristics in non-aqueous electrolyte solutions and low affinity for the metal-complex redox species compared to a commercial membrane. Consequently, the PFAEM is revealed to possess superior battery performance than a commercial membrane in the NARFB tests, showing high energy efficiency of about 85% and stable operation for 100 cycles. Full article