Batteries, Volume 9, Issue 11 (November 2023) – 38 articles

With the urgent demand for clean energy, rechargeable zinc–air batteries (ZABs) are attracting increasing attention. Precious-metal-based electrocatalysts (e.g., commercial Pt/C and IrO₂) are reported to be highly active towards the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Nevertheless, the limited catalytic kinetics, along with the scarcity of noble metals, still hinder the practical applications of ZABs. Consequently, it is of great importance to explore efficient bifunctional ORR/OER electrocatalysts with abundant reserves. Although iron oxides are considered to have some of the greatest potential as catalysts among the metal oxides, owing to their excellent redox properties, lower toxicity, simple preparation, and natural abundance, their poor electrical conductivity and high agglomeration still limit their development. In this work, we report a special Se quantum dots@ CoFeO_x (Se-FeO_x-Co) composite material, which exhibits outstanding bifunctional catalytic properties. And the potential gap between ORR and OER is low at 0.87 V. In addition, the ZAB based on Se-FeO_x-Co achieves a satisfactory open-circuit voltage (1.46 V) along with an operation durability over 800 min. This research explores an effective strategy to fabricate iron oxide-based bifunctional catalysts, which contributes to the future design of related materials. Full article

All-solid-state lithium batteries without any liquid organic electrolytes can realize high energy density while eliminating flammability issues. Active materials with high specific capacity and favorable interfacial contact within the cathode layer are crucial to the realization of good electrochemical performance. Herein, we report a high-capacity polysulfide cathode material, MoS₆@15%Li₇P₃S₁₁, with a particle size of 1–4 μm. The MoS₆ exhibited an impressive initial specific capacity of 913.9 mAh g⁻¹ at 0.1 A g⁻¹. When coupled with the Li₇P₃S₁₁ electrolyte coating layer, the resultant MoS₆@15%Li₇P₃S₁₁ composite showed improved interfacial contact and an optimized ionic diffusivity range from 10⁻¹²–10⁻¹¹ cm² s⁻¹ to 10⁻¹¹–10⁻¹⁰ cm² s⁻¹. The Li/Li₆PS₅Cl/MoS₆@15%Li₇P₃S₁₁ all-solid-state lithium battery delivered ultra-high initial and reversible specific capacities of 1083.8 mAh g⁻¹ and 851.5 mAh g⁻¹, respectively, at a current density of 0.1 A g⁻¹ within 1.0–3.0 V. Even under 1 A g⁻¹, the battery maintained a reversible specific capacity of 400 mAh g⁻¹ after 1000 cycles. This work outlines a promising cathode material with intimate interfacial contact and superior ionic transport kinetics within the cathode layer as well as high specific capacity for use in all-solid-state lithium batteries. Full article

The limitations of existing commercial indirect liquid cooling have drawn attention to direct liquid cooling for battery thermal management in next-generation electric vehicles. To commercialize direct liquid cooling for battery thermal management, an extensive database reflecting performance and operating parameters needs to be established. The development of prediction models could generate this reference database to design an effective cooling system with the least experimental effort. In the present work, artificial neural network (ANN) modeling is demonstrated to predict the thermal and electrical performances of batteries with direct oil cooling based on various operating conditions. The experiments are conducted on an 18650 battery module with direct oil cooling to generate the learning data for the development of neural network models. The neural network models are developed considering oil temperature, oil flow rate, and discharge rate as the input operating conditions and maximum temperature, temperature difference, heat transfer coefficient, and voltage as the output thermal and electrical performances. The proposed neural network models comprise two algorithms, the Levenberg–Marquardt (LM) training variant with the Tangential-Sigmoidal (Tan-Sig) transfer function and that with the Logarithmic-Sigmoidal (Log-Sig) transfer function. The ANN_LM-Tan algorithm with a structure of 3-10-10-4 shows accurate prediction of thermal and electrical performances under all operating conditions compared to the ANN_LM-Log algorithm with the same structure. The maximum prediction errors for the ANN_LM-Tan and ANN_LM-Log algorithms are restricted within ±0.97% and ±4.81%, respectively, considering all input and output parameters. The ANN_LM-Tan algorithm is suggested to accurately predict the thermal and electrical performances of batteries with direct oil cooling based on a maximum determination coefficient (R²) and variance coefficient (COV) of 0.99 and 1.65, respectively. Full article

Silicon is a promising anode material and can already be found in commercially available lithium-ion cells. Reliable modeling and simulations of new active materials for lithium-ion batteries are becoming more and more important, especially regarding cost-efficient cell design. Because literature lacks an electrochemical model for silicon-dominant electrodes, this work aims to close the gap. To this end, a Newman p2D model for a lithium-ion cell with a silicon-dominant anode and a nickel-cobalt-aluminum-oxide cathode is parametrized. The micrometer silicon particles are partially lithiated to 1200 mAh ${\mathrm{g}}_{\mathrm{Si}}^{-1}$. The parametrization is based on values from the electrode manufacturing process, measured values using lab cells, and literature data. Charge and discharge tests at six different C-rates up to 2C serve as validation data, showing a root-mean-squared error of about 21 mV and a deviation in discharge capacity of about 1.3%, both during a 1 C constant current discharge. Overall, a validated parametrization for a silicon-dominant anode is presented, which, to the best of our knowledge, is not yet available in literature. For future work, more in-depth studies should investigate the material parameters for silicon to expand the data available in the literature and facilitate further simulation work. Full article

Binders play a pivotal role in the production and the operation of lithium-ion batteries. They influence a number of key dispersion characteristics and battery parameters. In the light of growing interest in additive manufacturing technologies, binders were found to decisively govern the processability due to the induced complex non-Newtonian behavior. This paper examines the relevance of various binder derivatives for aqueous graphite dispersions that can be employed in inkjet printing. Two different carboxymethyl cellulose (CMC) derivatives with strongly deviating molecular weights were employed. The impact of the inherent polymer characteristics on the processability and the electrode characteristics were explored. Therefore, miscellaneous studies were carried out at the dispersion, the electrode, and the cell levels. The results revealed that the CMC with the lower molecular weight affected most of the studied characteristics more favorably than the counterpart with a higher molecular weight. In particular, the processability, encompassing drop formation and drop deposition, the cohesion behavior, and the electrochemical characteristics, were positively impacted by the low-molecular-weight CMC. The adhesion behavior was enhanced using the high-molecular-weight CMC. This demonstrates that the selection of a suitable binder derivative merits close attention. Full article

Electrospinning polyvinyl alcohol (PVA) nanofibrous membranes have gained increased attention for their uses as separators for lithium-ion batteries (LIBs) due to their high porosity and excellent electrolyte wettability, but their poor mechanical and thermal properties have limited their further development. In this work, a crosslinked PVA composite separator (PVA/CA-H) was first prepared via the electrospinning of the PVA and citric acid (CA) mixed solution and then the heating of the nanofibrous membrane, and the effects of the amount of CA on the structure and performance of the PVA/CA-H separator were investigated. The hydroxyl group of PVA and the carboxyl group of CA were crosslinked under the heat treatment, resulting in a slight reduction in the porosity and pore size of the composite separator compared to pure PVA, and to compensate for this issue, the mechanical strengths, as well as the thermal dimensional stability of the PVA/CA-H separator, were significantly improved. Meanwhile, the PVA/CA-H separator exhibited good electrolyte uptake (158.1%) and high ionic conductivity (1.63 mS cm⁻¹), and, thus, the battery assembled with the PVA/CA-H separator exhibited a capacity retention of 96.3% after 150 cycles at 1 C. These features mean that the crosslinked PVA composite separator can be considered as a prospective high-safety and high-performance separator for LIBs. Full article

Developments in different battery chemistries and cell formats play a vital role in the final performance of the batteries found in the market. However, battery manufacturing process steps and their product quality are also important parameters affecting the final products’ operational lifetime and durability. In this review paper, we have provided an in-depth understanding of lithium-ion battery manufacturing in a chemistry-neutral approach starting with a brief overview of existing Li-ion battery manufacturing processes and developing a critical opinion of future prospectives, including key aspects such as digitalization, upcoming manufacturing technologies and their scale-up potential. In this sense, the review paper will promote an understanding of the process parameters and product quality. Full article

An inorganic solid electrolyte is the most favorable candidate for replacing flammable liquid electrolytes in lithium batteries. Lithium lanthanum zirconium oxide (LLZO) is considered a promising solid electrolyte due to its safe operating potential window (0–5 V) combined with its good electrochemical stability. In this work, 250 g batches of pre-sintered Ta-doped LLZO (Li₇La₃Zr_1.6Ta_0.4O₁₂, Ta-LLZO) were synthesized for bulk production of a dense LLZO electrolyte. A simple two-step thermal treatment process was developed. The first thermal step at 950 °C initiates nucleation of LLZO, with carefully controlled process parameters such as heating atmosphere, temperature, and dopant concentration. In the second thermal step at 1150 °C, sintered discs were obtained as solid electrolytes, with relative densities of 96%. X-ray diffraction analysis confirmed the phase purity of the sintered Ta-LLZO disc, and refined data were used to calculate the lattice parameter (12.944 Å). Furthermore, the presence of the Ta dopant in the disc was confirmed through X-ray photoelectron spectroscopy (XPS) analysis. The ionic and electronic conductivity values of the Ta-LLZO disc were 10⁻⁴ S cm⁻¹ and 10⁻¹⁰ S cm⁻¹, respectively. These values confirm that the prepared (Ta-LLZO) discs exhibit ionic conductivity while being electronically insulating, being suitable for use as solid electrolytes with the requisite electrical properties. Full article

Modern vehicles have increasing safety requirements and a need for reliable low-voltage power supply in their on-board power supply systems. Understanding the causes and probabilities of failures in a 12 V power supply is crucial. Field analyses of aged and failed 12 V lead batteries can provide valuable insights regarding this topic. In a previous study, non-invasive electrical testing was used to objectively determine the reasons for failure and the lifetime of individual batteries. By identifying all of the potential failure mechanisms, the Latin hypercube sampling method was found to effectively reduce the required sample size. To ensure sufficient confidence in validating diagnostic algorithms and calculating time-dependent failure rates, all identified aging phenomena must be considered. This study presents a probability distribution of the failure mechanisms that occur in the field, as well as provides insights into potential opportunities, but it also challenges diagnostic approaches for current and future vehicles. Full article

Lithium-ion batteries (LIBs) are widely used as power sources for electric vehicles due to their various advantages, including high energy density and low self-discharge rate. However, the safety challenges associated with LIB thermal runaway (TR) still need to be addressed. In the present study, the effects of the battery SOC value and coolant flow rate on the TR behavior in a LIB pack are comprehensively investigated. The battery pack consists of 10 18650-type LIBs applied with the serpentine channel liquid-cooling thermal management system (TMS). The TR tests for various SOC values (50%, 75% and 100%) and coolant flow rates (0 L/h, 32 L/h, 64 L/h and 96 L/h) are analyzed. The retarding effect of the TMS on TR propagation is found to be correlated with both the coolant flow rate and the battery SOC value, and a larger coolant flow rate and lower SOC generally result in fewer TR batteries. Furthermore, the TR propagation rate, evaluated by the time interval of TR occurrence between the adjacent batteries, increases with the battery SOC. The battery pack with 100% SOC shows more rapid TR propagation, which can be completed in just a few seconds, in contrast to several minutes for 50% and 75% SOC cases. In addition, the impact of the battery SOC and coolant flow rate on the maximum temperature of the TR battery is also examined, and no determined association is observed between them. However, it is found that the upstream batteries (closer to the external heater) show a slightly higher maximum temperature than the downstream ones, indicating a weak association between the TR battery maximum temperature and the external heating duration or the battery temperature at which the TR starts to take place. Full article

Poor cycling performance caused by massive volume expansion of silicon (Si) has always hindered the widespread application of silicon-based anode materials. Herein, bi-continuous silicon/carbon (Si/C) anode materials are prepared via magnesiothermic reduction of silica aerogels followed by pitch impregnation and carbonization. To fabricate the expected bi-continuous structure, mesoporous silica aerogel is selected as the raw material for magnesiothermic reduction. It is successfully reduced to mesoporous Si under the protection of NaCl. The as-obtained mesoporous Si is then injected with molten pitch via vacuuming, and the pitch is subsequently converted into carbon at a high temperature. The innovative point of this strategy is the construction of a bi-continuous structure, which features both Si and carbon with a cross-linked structure, which provides an area to accommodate the colossal volume change of Si. The pitch-derived carbon facilitates fast lithium ion transfer, thereby increasing the conductivity of the Si/C anode. It can also diminish direct contact between Si and the electrolyte, minimizing side reactions between them. The obtained bi-continuous Si/C anodes exhibit excellent electrochemical performance with a high initial discharge capacity of 1481.7 mAh g⁻¹ at a current density of 300 mA g⁻¹ and retaining as 813.5 mAh g⁻¹ after 200 cycles and an improved initial Coulombic efficiency of 82%. The as-prepared bi-continuous Si/C anode may have great potential applications in high-performance lithium-ion batteries. Full article

Lithium-ion batteries have rapidly become the most widely used energy storage devices in mobile electronic equipment, electric vehicles, power grid energy storage devices and other applications. Due to their outstanding stability and high conductivity, carbon materials are among the most preferred anode materials for lithium-ion batteries. In this study, mesophase pitch-based graphite fibers (GFs) were successfully prepared through melt-spinning, thermo-oxidative stabilization, carbonization and graphitization and used as anode materials. The radial fiber structure can lower the activation energy and minimize the distance of the Li⁺ diffusion, while the highly conductive cross-linked network within the fibers benefits the speed up charge transmission. Thus, the as-synthesized graphite fibers demonstrate superior rate capability and cycle stability. GFs exhibit a capacity retention rate of 97.94% and reversible capacity of 327.8 mA h g⁻¹ after 100 cycles at 0.1 C, which is higher than that of natural graphite anode materials (85.66% and 289.7 mA h g⁻¹, respectively). Moreover, the as-synthesized graphite fibers deliver a capacity retention of 64.7% at a high rate of 5 C, which is considerably higher than that of natural graphite (19.7%). Full article

The processing and extraction of critical metals from black mass is important to battery recycling. Separation and recovery of critical metals (Co, Ni, Li, and Mn) from other metal impurities must yield purified metal salts, while avoiding substantial losses of critical metals. Solvent extraction in batch experiments were conducted using mixed metal sulphates obtained from the leach liquor obtained from spent and shredded lithium-ion batteries. Selective extraction of Mn²⁺, Fe³⁺, Al³⁺ and Cu²⁺ from simulated and real leached mixed metals solution was carried out using di-2-ethylhexylphophoric acid (D2EPHA) and Cyanex-272 at varying pH. Further experiments with the preferred extractant (D2EPHA) were performed under different conditions: changing the concentration of extractant, organic to aqueous ratio, and varying the diluents. At optimum conditions (40% v/v D2EPHA in kerosene, pH 2.5, O:A = 1:1, 25 °C, and 20 min), 85% Mn²⁺, 98% Al³⁺, 100% Fe³⁺, and 43% Cu²⁺ were extracted with losses of only trace amounts (<5.0%) of Co²⁺, Ni²⁺, and Li⁺. The order of extraction efficiency for the diluents was found to be kerosene > Exxal-10 >>> dichloromethane (CH₂Cl₂) > toluene. Four stages of stripping of metals loaded on D2EPHA were performed as co-extracted metal impurities were selectively stripped, and a purified MnSO₄ solution was produced. Spent extractant was regenerated after Fe³⁺ and Al³⁺ were completely stripped using 1.0 M oxalic acid (C₂H₂O₄). Full article

For the first time, the laser structuring of large-footprint electrodes with a loading of 4 mAh cm⁻² has been validated in a relevant environment, including subsequent multi-layer stack cell assembly and electrochemical characterization of the resulting high-capacity lithium-ion pouch cell prototypes, i.e., a technological readiness level of 6 has been achieved for the 3D battery concept. The structuring was performed using a high-power ultrashort-pulsed laser, resulting in well-defined line structures in electrodes without damaging the current collector, and without melting or altering the battery active materials. For cells containing structured electrodes, higher charge and discharge capacities were measured for C-rates >1C compared to reference cells based on unstructured electrodes. In addition, cells with structured electrodes showed a three-fold increase in cycle lifetime at a C-rate of 1C compared to those with reference electrodes. Full article

Battery state of health (SOH) is a significant metric for evaluating battery life and predicting battery safety. Currently, SOH research is largely based on laboratory data, with a dearth of research on electric vehicle (EV) operating data. Due to the difficulty in obtaining complete charge data under EV operating conditions, this study presents a SOH estimation method utilizing deep network adaptation. First, a data-driven approach is employed to extract voltage, current, state of charge (SOC), and incremental capacity (IC) data features. To compensate for the lack of aging information in the EV operation data domain, transfer learning is employed to construct the SOH estimation model. Additionally, to resolve inconsistent data distribution between the source laboratory battery data domain and the target EV operation data domain, an adaptive layer is added to the network, and adaptation of deep network (ADN) is utilized to enhance the model’s performance. Finally, the model is validated using electric bus operational data. Results indicate that this model’s average Mean Absolute Error (MAE) is less than 3.0%, and, compared to support vector machine (SVM) regression and Gaussian Process Regression (GPR) algorithms, the MAE is reduced by 27.7% and 38.4%, respectively. Full article

Three-dimensional (3D) printing, as an advanced additive manufacturing technique, is emerging as a promising material-processing approach in the electrical energy storage and conversion field, e.g., electrocatalysis, secondary batteries and supercapacitors. Compared to traditional manufacturing techniques, 3D printing allows for more the precise control of electrochemical energy storage behaviors in delicately printed structures and reasonably designed porosity. Through 3D printing, it is possible to deeply analyze charge migration and catalytic behavior in electrocatalysis, enhance the energy density, cycle stability and safety of battery components, and revolutionize the way we design high-performance supercapacitors. Over the past few years, a significant amount of work has been completed on 3D printing to explore various high-performance energy-related materials. Although impressive strides have been made, challenges still exist and need to be overcome in order to meet the ever-increasing demand. In this review, the recent research progress and applications of 3D-printed electrocatalysis materials, battery components and supercapacitors are systematically presented. Perspectives on the prospects for this exciting field are also proposed with applicable discussion and analysis. Full article

Ion-selective membranes based on non-ionic polymers are promising for redox flow batteries due to their superior chemical stability and low cost. In this work, a poly(vinylidene fluoride) (PVDF) ion-selective membrane is successfully prepared using a solvent-controlled swelling method, where Nafion is used as a channel-forming promoter. The influences of Nafion on the channel formation of the membranes are studied. The results indicate that the addition of Nafion resin can greatly promote the formation of ion-conducting channels in the PVDF matrix. The obtained membranes show well-controlled proton conductivity and proton/vanadium selectivity. A battery test on a vanadium redox flow single cell is successfully performed. The energy efficiency of the cell equipped with the PVDF-based ion-selective membrane reaches 81.7% at a current density of 60 mA cm⁻² and possesses excellent cycling stability and suppressed self-discharge after modification with Nafion. Full article

Lithium batteries have recently attracted significant attention as highly promising energy storage devices within the secondary battery industry. However, it is important to note that they may pose safety risks, including the potential for explosions during use. Therefore, achieving stable and safe utilization of these batteries necessitates accurate state-of-charge (SOC) estimation. In this study, we propose a hybrid model combining temporal convolutional network (TCN) and eXtreme gradient boosting (XGBoost) to investigate the nonlinear and evolving characteristics of batteries. The primary goal is to enhance SOC estimation performance by leveraging TCN’s long-effective memory capabilities and XGBoost’s robust generalization abilities. We conducted experiments using datasets from NASA, Oxford, and a vehicle simulator to validate the model’s performance. Additionally, we compared the performance of our model with that of a multilayer neural network, long short-term memory, gated recurrent unit, XGBoost, and TCN. The experimental results confirm that our proposed TCN–XGBoost hybrid model outperforms the other models in SOC estimation across all datasets. Full article

Solid-state batteries (SSBs) with Li-ion conductive electrolytes made from polymers, thiophosphates (sulfides) or oxides instead of liquid electrolytes have different challenges in material development and manufacturing. For oxide-based SSBs, the co-sintering of a composite cathode is one of the main challenges. High process temperatures cause undesired decomposition reactions of the active material and the solid electrolyte. The formed phases inhibit the high energy and power density of ceramic SSBs. Therefore, the selection of suitable material combinations as well as the reduction of the sintering temperatures are crucial milestones in the development of ceramic SSBs. In this work, the co-sintering behavior of Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) as a solid electrolyte with Li-ion conductivity of ≥0.38 mS/cm and LiFePO₄ with a C-coating (LFP) as a Li-ion storage material (active material) is investigated. The shrinkage behavior, crystallographic analysis and microstructural changes during co-sintering at temperatures between 650 and 850 °C are characterized in a simplified model system by mixing, pressing and sintering the LATP and LFP and compared with tape-casted composite cathodes (d = 55 µm). The tape-casted and sintered composite cathodes were infiltrated by liquid electrolyte as well as polyethylene oxide (PEO) electrolyte and electrochemically characterized as half cells against a Li metal anode. The results indicate the formation of reaction layers between LATP and LFP during co-sintering. At T_s > 750 °C, the rhombohedral LATP phase is transformed into an orthorhombic Li_1.3+xAl_0.3−yFe_x+yTi_1.7−x(PO₄)₃ (LAFTP) phase. During co-sintering, Fe³⁺ diffuses into the LATP phase and partially occupies the Al³⁺ and Ti⁴⁺ sites of the NASICON structure. The formation of this LAFTP leads to significant changes in the electrochemical properties of the infiltrated composite tapes. Nevertheless, a high specific capacity of 134 mAh g⁻¹ is measured by infiltrating the sintered composite tapes with liquid electrolytes. Additionally, infiltration with a PEO electrolyte leads to a capacity of 125 mAh g⁻¹. Therefore, the material combination of LATP and LFP is a promising approach to realize sintered ceramic SSBs. Full article

Upon reaching certain limits, electric vehicle batteries are replaced and may find a second life in various applications. However, the state of such batteries in terms of aging and safety remains uncertain when they enter the second-life market. The aging mechanisms within these batteries involve a combination of processes, impacting their safety and performance. Presently, direct health indicators (HIs) like state of health (SOH) and internal resistance increase are utilized to assess battery aging, but they do not always provide accurate indications of the battery’s health state. This study focuses on analyzing various HIs obtained through a basic charging–discharging cycle and assessing their sensitivity to aging. Commercial 50 Ah pouch cells with different aging histories were tested, and the HIs were evaluated. Thirteen HIs out of 31 proved to be highly aging-sensitive, and thus good indicators. Namely, SOH upon charging and discharging, Coulombic efficiency, constant current discharge time, voltage relaxation profile trend, voltage–charge area upon discharging, hysteresis open circuit voltage HIs, and temperature difference between the tabs upon charging. The findings offer valuable insights for developing robust qualification algorithms and reliable battery health monitoring systems for second-life batteries, ensuring safe and efficient battery operation in diverse second-life applications. Full article

Excessive mechanical loading of lithium-ion batteries can impair performance and safety. Their ability to resist loads depends upon the properties of the materials they are made from and how they are constructed and loaded. Here, prismatic lithium-ion battery cell components were mechanically and optically characterized to examine details of material morphology, construction, and mechanical loading response. Tensile tests were conducted on the cell case enclosure, anodes, cathodes, and separators. Compression tests on stacks of anodes, cathodes, separators, and jellyrolls were made from them. Substantially differing behaviors were observed amongst all components tested. An optical examination of the anodes, cathodes, and separators revealed homogeneities, anisotropies, and defects. Substantial texturing was present parallel to the winding direction. When highly compressed, jellyrolls develop well-defined V-shaped cracks aligned parallel to the texturing. Like many laminates, altering the lay-up construction affects jellyroll mechanical performance. To demonstrate, a cross-ply jellyroll was fabricated by rotating every other complete component set (cathode/separator/anode/separator), reassembling, and compressing. A distinctly different fracture pattern and increased compressive strength were observed. Full article

Lithium-Ion battery cells and automotive battery systems are constantly improving as a result of the rising popularity of electric vehicles. With higher energy densities of the cells, the risks in case of failure rise as well. In the worst case, a fast exothermic reaction known as thermal runaway can occur. During thermal runaway, the cell can emit around 66% of its mass as gas and particles. An experimental setup was designed and showed that the gas-particle-vent of a cell going through thermal runaway can cause electric breakthroughs. These breakthroughs could start electric arcing in the battery system, which could lead to additional damages such as burning through the casing or igniting the vent gas, making the damage more severe and difficult to control. Uncontrollable battery fires must be prevented. The emitted gas was analyzed and the ejected particles were examined to discuss the potential causes of the breakthroughs. Full article

With the rapid development of machine learning and cloud computing, deep learning methods based on big data have been widely applied in the assessment of lithium-ion battery health status. However, enhancing the accuracy and robustness of assessment models remains a challenge. This study introduces an innovative T-LSTM prediction network. Initially, a one-dimensional convolutional neural network (1DCNN) is employed to effectively extract local and global features from raw battery data, providing enriched inputs for subsequent networks. Subsequently, LSTM and transformer models are ingeniously combined to fully utilize their unique advantages in sequence modeling, further enhancing the accurate prediction of battery health status. Experiments were conducted using both proprietary and open-source datasets, and the results validated the accuracy and robustness of the proposed method. The experimental results on the proprietary dataset show that the T-LSTM-based estimation method exhibits excellent performance in various evaluation metrics, with MSE, RMSE, MAE, MAPE, and MAXE values of 0.43, 0.66, 0.53, 0.58, and 1.65, respectively. The performance improved by 30–50% compared to that of the other models. The method demonstrated superior performance in comparative experiments, offering novel insights for optimizing intelligent battery management and maintenance strategies. Full article

In this study, the effects of battery thermal management (BTM), pumping power, and heat transfer rate were compared and analyzed under different operating conditions and cooling configurations for the liquid cooling plate of a lithium-ion battery. The results elucidated that when the flow rate in the cooling plate increased from 2 to 6 L/min, the average temperature of the battery module decreased from 53.8 to 50.7 °C, but the pumping power increased from 0.036 to 0.808 W. In addition, an increase in the width of the cooling channel and number of channels resulted in a decrease in the average temperature of the battery module and a reduction in the pumping power. The most influential variable for the temperature control of the battery was an increase in the flow rate. In addition, according to the results of the orthogonal analysis, an increase in the number of cooling plate channels resulted in the best cooling performance and reduced pumping power. Based on this, a cooling plate with six channels was applied to both the top and bottom parts, and the top and bottom cooling showed sufficient cooling performance in maintaining the average temperature of the battery module below 45 °C. Full article

Lithium–ion batteries (LIBs) are used in many personal electronic devices (PED) and energy-demanding applications such as electric vehicles. After their first use, rather than dispose of them for recycling, some may still have reasonable capacity and can be used in secondary applications. The current test methods to assess them are either slow, complex or expensive. The voltage integral during the constant current (CC) charge of the same model of LIBs strongly correlates with the state of health (SOH) and is faster than a full capacity check. Compared to the filtering requirement in the incremental capacity (IC) and differential voltage (DV) or the complex analysis in the electrochemical impedance spectrum (EIS), the voltage integral offers a simple integration method, just like the simple capacity Coulomb’s counter that is installed in many BMS for estimating the SOC of LIBs. By obtaining the voltage integral of a relatively new cell and an old cell of the same model with known SOH at a given ambient temperature and CC charge, the SOH of other similar cells can be easily estimated by finding their voltage integrals. Full article

The literature indicates that utilizing pyrometallurgical methods for processing spent LiCoO₂ (LCO) batteries can lead to cobalt recovery in the forms of Co₃O₄, CoO, and Co, while lithium can be retrieved as Li₂O or Li₂CO₃. However, the technology’s high energy consumption has also been noted as a challenge in this recovery process. Recently, an innovative and sustainable approach using microwave (MW) radiation has been proposed as an alternative to traditional pyrometallurgical methods for treating used lithium-ion batteries (LiBs). This method aims to address the shortcomings of the conventional approach. In this study, the treatment of the black mass (BM) from spent LCO batteries is explored for the first time using MW–materials interaction under an air atmosphere. The research reveals that the process can trigger carbothermic reactions. However, MW makes the BM so reactive that it causes rapid heating of the sample in a few minutes, also posing a fire risk. This paper presents and discusses the benefits and potential hazards associated with this novel technology for the recovery of spent LCO batteries and gives information about real samples of BM. The work opens the possibility of using a microwave for raw material recovery in spent LIBs, allowing to obtain rapid and more efficient reactions. Full article

Interest in printed batteries is growing due to their applications in our daily lives, e.g., for portable and wearable electronics, biomedicals, and internet of things (IoT). The main advantages offered by printing technologies are flexibility, customizability, easy production, large area, and high scalability. Among the printing techniques, gravure is the most appealing for the industrial manufacture of functional layers thanks to its characteristics of high quality and high speed. To date, despite its advantages, such technology has been little investigated, especially in the field of energy since it is difficult to obtain functionality and adequate mass loading using diluted inks. In this review, the recent results for printed lithium-ion batteries are reported and discussed. A methodology for controlling the ink formulation and process based on the capillary number was proposed to obtain high printing quality and layer functionality. Specific concerns were found to play a fundamental role for each specific material and its performance when used as a film. Considering all such issues, gravure can provide high performance layers. A multilayer approach enables the desired layer mass loading to be achieved with advantages in terms of bulk homogeneity. Such results can boost the future industrial employment of gravure printing in the field of printed batteries. Full article

The revolution in lithium-ion battery (LIB) technology was partly due to the invention of graphite as a robust negative electrode material. However, equivalent negative electrode materials for complementary sodium ion battery (NIB) technologies are yet to be commercialized due to sluggish reaction kinetics, phase instability, and low energy density originating from the larger size of Na⁺-ion. Therefore, in search of the next-generation electrode materials for NIBs, we first analyze the failure of graphite during reversible Na⁺ ion storage. Building upon that, we suggest surface-functionalized and nanostructured forms of analogous carbon allotropes for enhancing Na+ ion storage. During long-term rigorous cycling conditions, Graphene Oxide (GO) and Graphene nanoplatelets (GNP) exhibit higher Na⁺ ion storage (157 mAh g⁻¹ and 50 mAh g⁻¹ after 60 cycles, respectively) compared to graphite (27 mAh g⁻¹). Optimizing alternative NIBs requires a comprehensive analysis of cycling behavior and kinetic information. Therefore, in this investigation, we further examine ex-situ electrochemical impedance spectroscopy (EIS) at progressive cycles and correlate capacity degradation with impedance arising from the electrolyte, solid electrolyte interphase formation, and charge transfer. Full article

Lithium-ion capacitors (LiC) are promising hybrid devices bridging the gap between batteries and supercapacitors by offering simultaneous high specific power and specific energy. However, an indispensable critical component in LiC is the capacitive cathode for high power. Activated carbon (AC) is typically the cathode material due to its low cost, abundant raw material for production, sustainability, easily tunable properties, and scalability. However, compared to conventional battery-type cathodes, the low capacity of AC remains a limiting factor for improving the specific energy of LiC to match the battery counterparts. This review discusses recent approaches for achieving high-performance LiC, focusing on the AC cathode. The strategies are discussed with respect to active material property modifications, electrodes, electrolytes, and cell design techniques which have improved the AC’s capacity/capacitance, operating potential window, and electrochemical stability. Potential strategies and pathways for improved performance of the AC are pinpointed. Full article

The practical usage of sodium metal batteries is mainly hampered by their potential safety risks caused by conventional liquid-state electrolytes. Hence, solid-state sodium metal batteries, which employ inorganic solid electrolytes and/or solid-state polymer electrolytes, are considered an emerging technology for addressing the safety hazards. Unfortunately, these traditional inorganic/polymer solid electrolytes, most of which are prepared via ex-situ methods, frequently suffer from inadequate ionic conductivity and sluggish interfacial transportation. In light of this, in-situ polymerized solid-state polymer electrolytes are proposed to simplify their preparation process and simultaneously address these aforementioned challenges. In this review, the up-to-date research progress of the design, synthesis, and applications of this kind of polymer electrolytes for sodium batteries of high safety via several in-situ polymerization methods (including photoinduced in-situ polymerization, thermally induced in-situ free radical polymerization, in-situ cationic polymerization, and cross-linking reaction) are summarized. In addition, some perspectives, opportunities, challenges, and potential research directions regarding the further development of in-situ fabricated solid-state polymer electrolytes are also provided. We expect that this review will shed some light on designing high-performance solid-state polymer electrolytes for building next-generation sodium batteries with high safety and high energy. Full article