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Among various metal oxide nanomaterials, manganese oxides, which can exist in different structures and valence states, are considered highly promising anode materials for lithium-ion batteries (LIBs). However, conventional manganese oxides, such as MnO and MnO2, face significant challenges during cycling process. Specifically, poor electronic conductivity and large volume changes result in low specific capacity during high current charging and discharging, as well as poor fast-charging performance. This work presents an approach to synthesizing porous hexagonal Mn5O8 nanosheets via hydrothermal and annealing methods and applies them as anode materials for LIBs. The Mn5O8 nanomaterials exhibit a thin plate morphology, which effectively reduces the distance for ion/electron transmission and mitigates the phenomenon of volume expansion. Additionally, the large pore size of Mn5O8 results in abundant interlayer and intralayer defects, which further increase the rate of ion transmission. These unique characteristics enable Mn5O8 to demonstrate excellent electrochemical performance (938.7 mAh·g−1 after 100 cycles at 100 mA·g−1) and fast charging performance (675.7 mAh·g−1 after 1000 cycles at 3000 mA·g−1), suggesting that Mn5O8 nanosheets have the potential to be an ideal fast-charging anode material for LIBs.

This work provides a comprehensive analysis and evaluation of the interface enhancement achieved by applying a hard carbon coating to graphite, investigating the optimization of lithium deposition and the improvement of fast charging performance. Compared to the original graphite, the hard carbon-coated graphite (HCCG) shows an approximately 8% increase in reversible lithium content, a threefold increase in exchange current density, and a reduction in the Tafel slope to one-quarter of that of the original graphite. [Display omitted] Due to the inherent characteristics of traditional graphite anode material, its lithium diffusion kinetic is significantly constrained, easily leading to a noticeable capacity degradation during rapid charge/discharge cycling. Although modifying the graphite by mixing the hard carbon can effectively enhance its fast-charging performance, yet the underlying mechanism of improvement effect and structure design of interface are still needed to further investigate. To address this research gap, hard carbon-coated graphite (HCCG) material has been designed and synthesized through simple interface engineering, which is aimed to explore and elucidate the optimization mechanisms on fast-charging performance from the graphite interface perspective. According to the electrochemical calculations, the HCCG anode exhibits significant enhancements. Specially, its reversible lithium content is increased by approximately 8 % at various states of charge, its exchange current density is tripled, and its Tafel slope is reduced to one-quarter of the original graphite. Therefore, the HCCG maintains an impressive 86.89 % capacity retention and a high capacity of 202.3 mAh g−1 after 1450 cycles at ultrahigh rate of 5C. These improvements indicate a substantial reduction in electrode polarization during fast charging, which is ascribed to the abundant lithium intercalation pathways and accommodation space provided by the intimate hard carbon coating layer. Moreover, as a "buffer layer," hard carbon coating can accommodate considerable amount of lithium deposited on the graphite surface, effectively mitigating the capacity loss caused by lithium deposition and maintaining effective electrochemical contact without delamination. This comprehensive analysis of hard carbon coating illustrates the improvement mechanism of fast-charging performance, which can offer valuable insights into the dynamic and structural optimization of graphite anode interfaces. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) with the “double-high” characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics. However, the lithium ion (Li+)-storage performance of the most commercialized lithium cobalt oxide (LiCoO2, LCO) cathodes is still far from satisfactory in terms of high-voltage and fast-charging capabilities for reaching the double-high target. Herein, we systematically summarize and discuss high-voltage and fast-charging LCO cathodes, covering in depth the key fundamental challenges, latest advancements in modification strategies, and future perspectives in this field. Comprehensive and elaborated discussions are first presented on key fundamental challenges related to structural degradation, interfacial instability, the inhomogeneity reactions, and sluggish interfacial kinetics. We provide an instructive summary of deep insights into promising modification strategies and underlying mechanisms, categorized into element doping (Li-site, cobalt-/oxygen-site, and multi-site doping) for improved Li+ diffusivity and bulk-structure stability; surface coating (dielectrics, ionic/electronic conductors, and their combination) for surface stability and conductivity; nanosizing; combinations of these strategies; and other strategies (i.e., optimization of the electrolyte, binder, tortuosity of electrodes, charging protocols, and pre-lithiation methods). Finally, forward-looking perspectives and promising directions are sketched out and insightfully elucidated, providing constructive suggestions and instructions for designing and realizing high-voltage and fast-charging LCO cathodes for next-generation double-high LIBs.

To establish battery electric vehicles as an attractive alternative to internal combustion vehicles, charging times of 15 min or less are increasingly demanded. This is especially challenging for lower battery temperatures, as this exacerbates the risk of accelerated battery degradation due to lithium plating. Therefore, active battery heating is utilized in state-of-the-art electric vehicles. To evaluate the impact of such heating strategies at vehicle level, we deployed an electrochemical battery model coupled with a longitudinal vehicle dynamics model. Using anode potential control to prevent lithium plating, we assess the time-saving potential versus the energy cost of different preconditioning and fast-charging strategies. The results reveal substantial energy saving and charge speed increase potential through optimal charge-stop planning, preconditioning timing, cost-adjusted thermal management thresholds, and considering driving behavior. This emphasizes the need for advanced operation strategies, taking into account both battery-level electrical and thermal restrictions, as well as vehicle integration and route planning. [ABSTRACT FROM AUTHOR]

Lithium metal anode (LMA) emerges as a promising candidate for lithium (Li)‐based battery chemistries with high‐energy‐density. However, inhomogeneous charge distribution from the unbalanced ion/electron transport causes dendritic Li deposition, leading to "dead Li" and parasitic reactions, particularly at high Li utilization ratios (low negative/positive ratios in full cells). Herein, an innovative LMA structural model deploying a hyperporous/hybrid conductive architecture is proposed on single‐walled carbon nanotube film (HCA/C), fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of LMA and enabling high‐energy‐density batteries. The HCA/C promotes uniform lithium deposition even under rapid charging (up to 5 mA cm−2) owing to its efficient mixed ion/electron conduction pathways. Thus, the HCA/C demonstrates stable cycling for 200 cycles with a low negative/positive ratio of 1.0 when paired with a LiNi0.8Co0.1Mn0.1O2 cathode (areal capacity of 5.0 mAh cm−2). Furthermore, a stacked pouch‐type full cell using HCA/C realizes a high energy density of 344 Wh kg−1cell/951 Wh L−1cell based on the total mass of the cell, exceeding previously reported pouch‐type full cells. This work paves the way for LMA development in high‐energy‐density Li metal batteries. [ABSTRACT FROM AUTHOR]

The most common pattern types for anode structuring, in particular the line, grid, and hexagonal-arranged hole pattern were evaluated in a comparable setup in full-cells and symmetrical cells. The cells with structured electrodes were compared to reference cells with unstructured anodes of similar areal capacity (4.3 mAh cm−2) and the onset of lithium plating during fast-charging was determined in situ by differential voltage analysis of the voltage relaxation and ex situ by post-mortem analysis. Furthermore, electrochemical impedance spectroscopy measurements on symmetrical cells were used to determine the ionic resistance of structured and unstructured electrodes of similar areal capacity. All cells with structured electrodes showed lower ionic resistances and an onset of lithium plating shifted to higher C-rates compared to cells with unstructured electrodes. The structure patterns with capillary structures, i.e., lines and grids, showed significant reduced lithium plating during fast-charging and a higher rate capability compared to reference cells with unstructured electrodes and cells with hole structured electrodes. The continuous rewetting of the electrode with liquid electrolyte by capillary forces and the reduced ionic resistance of the 3D electrode are identified as key factors in improving overall battery performance. The data of the studied cells were used to calculate the resulting energy and power densities of prospective commercial pouch cells and potential pitfalls in the comparison to cells with unstructured electrodes were identified. [ABSTRACT FROM AUTHOR]

Amorphous CoO/Al 2 O 3 /C hybrids were synthesized using a simple pyrolysis method at various temperatures and reagent ratios. At 500 °C, CoO localized from homogenous distribution to quantum dots (∼10 nm) on the Al 2 O 3 /C matrix. X-ray photoelectron spectroscopy results suggested that the feed nitrate ions doped the hybrids with pyridinic (398.8 eV) and pyrrolic (400.55 eV) N, which ameliorated the electrochemical performance of the hybrids. The optimum pyrolysis temperature to obtain a reversible capacity of 0.45 Ah g−1 at the 1000th cycle at a current density of 1 A g−1 was 500 °C. However, owing to the polarization electrode, the specific capacity decreased by 54 % after increasing the material mass loading (0.5–3 mg cm−2), which resulted in a maximum areal capacity of 0.78 mAh cm−2. After regulating the C content in the hybrid, the loss in reversible capacity was only 29 % for an eight-fold gain in the mass-loading (0.4–3.2 mg cm−2) and the areal capacity was up to 1.13 mAh cm−2. The specific capacity of the optimized electrode was 0.52 Ah g−1 at the 1000th cycle. In addition, it only lost 28 % of its capacity along with a ten-fold increase in current density (0.2–2 A g−1). In a full cell test involving a LiNi 0.8 Mn 0.1 Co 0.1 O 2 -based cathode and a CoO/Al 2 O 3 /C-based anode, 91 % of the maximum theoretical specific capacity was obtained, whereas the capacity retention at the 100th cycle was 97 %. Electrochemical impedance spectra suggested that small resistances (<38 Ω) and high Li+ diffusivity (5.5–6.8 × 10−11 cm2 s−1) supported the fast-charging properties of the hybrid. [Display omitted] • Pyrolysis temperature affects CoO/Al 2 O 3 /C hybrid's cyclability via CoO's distribution. • Increasing C content in the hybrid improves electrode's polarization. • Current density, capacity balance, and electrolyte affects a full-cell's performance. [ABSTRACT FROM AUTHOR]

Improving lithium-ion transport in electrodes by controlling electrode microstructure is a promising option for enhancing the fast-charging capability of graphite anodes in lithium-ion batteries. Dry processing of electrodes based on a polytetrafluoroethylene binder has attracted considerable attention as an alternative to solvent-based wet processing. The morphology of graphite particles has a significant impact on electrode microstructure, but few reports have been published on dry-processed graphite anodes. In this work, we found that the morphology of graphite particles is a key factor to determine the fast-charging capability of the dry-processed graphite electrode as well as the microstructure of the dry-processed graphite electrode. X-ray microscopy combined with mercury porosimetry and symmetrical cell electrochemical impedance spectroscopy reveal that the difference in porosity between the top and bottom layers of a dry electrode with spherical graphite particles is greater than that of flake-shaped graphite particles, resulting in enhanced lithium-ion transport in the electrode and improved fast-charging capability at a high charging rate of 5C (17.5 mA cm−2). These findings supply insights into the effective design of dry-processed graphite anodes with an emphasis on fast-charging capability as well as the development of graphite anode materials for dry-processing based lithium-ion batteries.

Abstract Recent technological advancements, such as portable electronics and electric vehicles, have created a pressing need for more efficient energy storage solutions. Lithium‐ion batteries (LIBs) have been the preferred choice for these applications, with graphite being the standard anode material due to its stability. However, graphite falls short of meeting the growing demand for higher energy density, possessing a theoretical capacity that lags behind. To address this, researchers are actively seeking alternative materials to replace graphite in commercial batteries. One promising avenue involves lithium‐alloying materials like silicon and phosphorus, which offer high theoretical capacities. Carbon–silicon composites have emerged as a viable option, showing improved capacity and performance over traditional graphite or pure silicon anodes. Yet, the existing methods for synthesizing these composites remain complex, energy‐intensive, and costly, preventing widespread adoption. A groundbreaking approach is presented here: the use of a laser writing strategy to rapidly transform common organic carbon precursors and silicon blends into efficient “graphenic silicon” composite thin films. These films exhibit exceptional structural and energy storage properties. The resulting three‐dimensional porous composite anodes showcase impressive attributes, including ultrahigh silicon content, remarkable cyclic stability (over 4500 cycles with ∼40% retention), rapid charging rates (up to 10 A g−1), substantial areal capacity (>5.1 mAh cm−2), and excellent gravimetric capacity (>2400 mAh g−1 at 0.2 A g−1). This strategy marks a significant step toward the scalable production of high‐performance LIB materials. Leveraging widely available, cost‐effective precursors, the laser‐printed “graphenic silicon” composites demonstrate unparalleled performance, potentially streamlining anode production while maintaining exceptional capabilities. This innovation not only paves the way for advanced LIBs but also sets a precedent for transforming various materials into high‐performing electrodes, promising reduced complexity and cost in battery production.

Abstract Lithium metal anode (LMA) emerges as a promising candidate for lithium (Li)‐based battery chemistries with high‐energy‐density. However, inhomogeneous charge distribution from the unbalanced ion/electron transport causes dendritic Li deposition, leading to “dead Li” and parasitic reactions, particularly at high Li utilization ratios (low negative/positive ratios in full cells). Herein, an innovative LMA structural model deploying a hyperporous/hybrid conductive architecture is proposed on single‐walled carbon nanotube film (HCA/C), fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of LMA and enabling high‐energy‐density batteries. The HCA/C promotes uniform lithium deposition even under rapid charging (up to 5 mA cm−2) owing to its efficient mixed ion/electron conduction pathways. Thus, the HCA/C demonstrates stable cycling for 200 cycles with a low negative/positive ratio of 1.0 when paired with a LiNi0.8Co0.1Mn0.1O2 cathode (areal capacity of 5.0 mAh cm−2). Furthermore, a stacked pouch‐type full cell using HCA/C realizes a high energy density of 344 Wh kg−1cell/951 Wh L−1cell based on the total mass of the cell, exceeding previously reported pouch‐type full cells. This work paves the way for LMA development in high‐energy‐density Li metal batteries.

Highlights MPCF@VG@SiNDs/C, constructed by uniformly dispersing amorphous Si nanodots in carbon nanospheres that are welded on the wall of the macroporous carbon frameworks by vertical graphene, is synthesized and has achieved a few kilogram production per batch. Finite element imitation reveals that amorphous Si nanodots with high dispersity in carbon nanosphere can achieve ultra-low stress and strain values during lithiation. Unique low-strain property and fast-charging capability are achieved under industrial electrode conditions.

Fast-charging technology is the inevitable trend for electric vehicles (EVs). Current EVs’ lithium-ion batteries (LIBs) cannot provide ultrafast power input due to the capacity fading and safety hazards of graphite anode at high rates. Lithium vanadate oxide (Li3VO4) has been widely studied as fast-charging anode material due to its high capacity and stability at high rates. However, its highly safe characteristic under fast-charging has not been studied. In this study, a fast-charging anode material is synthesized by inserting Li3VO4 in Ti3C2Tx MXene framework. The morphologies of Li3VO4/Ti3C2Tx electrode after cycling at different rates were studied to analyze the dendrites growth. Electrochemical testing results demonstrate that Li3VO4/Ti3C2Tx composite displays high capacities of 151.6 mA h g−1 at 5 C and 87.8 mA h g−1 at 10 C, which are much higher than that of commercial graphite anode (51.9 mA h g−1 at 5 C and 17.0 mA h g−1 at 10 C). Moreover, Li3VO4/Ti3C2Tx electrode does not generate Li dendrite at high rates (5 and 10 C) while commercial graphite electrode grows many Li dendrites under the same conditions, demonstrating fast-charging and high safety of Li3VO4/Ti3C2Tx composite. Our work inspires promising fast-charging anode material design for LIBs.

Current research focuses on lithium-ion battery cells with a high energy density and efficient fast-charging capabilities. However, transport limitations, and, therefore, the uniform diffusion of lithium-ions across the electrode layers, remain a challenge and could lead to reduced cell performance. One approach to overcome these transport challenges is the use of subsequently produced two-layer anodes with the particle size variation of spherical graphite (x50 = 18 µm; x50 = 11 µm). Thereby, a defined pore network is created, which reduces the ionic resistance and ensuring improved fast charging capabilities. The analysis focuses on the evaluation of electrode properties and the electrochemical performance. By examining the pore size distribution of the anodes, it has been found that during the manufacturing of the two-layer anodes, carbon black and binder particles are transported into the existing microstructure of the lower layer, resulting in localized densification between the anode layers. This could also be supported by color measurements. This effect also extends to electrochemical investigations, with electrochemical impedance spectroscopy showing significantly lower ionic resistances in all two-layer anodes. Reduced ionic resistance and tortuosity near the separator due to absorption effects enhance the ion diffusion and have a direct impact on anode performance. Cell ageing analysis showed a significant capacity decrease of almost 15 mAh g −1 in the single-layer references only, in contrast to the stability of the two-layer anodes. This could also be attributed to the reduced ionic resistance and active counteraction of binder migration. In conclusion, this study highlights how subsequently produced two-layer anodes significantly shape the electrode properties and cell performance of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Environmental issues have reached global attention from both political and social perspectives. Many countries and companies around the world are adopting measures to help change current trends. Awareness of decarbonization in the transportation sector has led to an increasing development of energy storage systems in recent years, especially for ground vehicles. Batteries, due to their high efficiency, are one of the most attractive energy storage systems for vehicle propulsion. As for road vehicles, the growing interest in Electric Vehicles (EVs) is motivated by the fact that they reduce local emissions compared to traditional Internal Combustion Engine (ICE) vehicles. The purpose of the paper is to present a study on how to plan and implement vehicle charging infrastructure on motorways. In particular, a specific road in Italy is analyzed: the motorway A1 from Milan to Naples with a length of about 800 km. This motorway can be considered representative because it passes through some of Italy's most important cities and regions and may represent the backbone of Italy. A useful model for defining the optimal location of electric vehicle charging stations is presented within the paper. Starting with the data on the average daily traffic flows passing through the main nodes of the motorways section, the demand for the potential vehicles needed to define the number and dimension of charging stations and provide an adequate supply is estimated. The analysis was performed considering five-time horizons (year 2022 to year 2025) and four Scenarios involving the installation of 4, 8, 16, and 32 Charging Stations (CSs) in each service area, respectively. [ABSTRACT FROM AUTHOR]

Abstract Advancing fast‐charging technology is an important strategy for the development of alkali metal ion batteries (AMIBs). The exploitation of a new generation of anode material system with high‐rate performance, high capacity, and low risk of lithium/sodium/potassium plating is critical to realize fast‐charging capability of AMIBs while maintaining high energy density and safety. Among them, phosphorus‐based anodes including phosphorus anodes and metal phosphide anodes have attracted wide attention, due to their high theoretical capacities, safe reaction voltages, and natural abundance. In this review, we summarize the research progress of different phosphorus‐based anodes for fast‐charging AMIBs, including material properties, mechanisms for storing alkali metal ions, key challenges and solution strategies for achieving fast‐charging capability. Moreover, the future development directions of phosphorus‐based anodes in fast‐charging AMIBs are highlighted.

The use of batteries in modern electronic devices and electric cars is becoming increasingly important. Batteries with high energy density, high rate and cycle capability, as well as operational safety, are in high demand today. The cathode of a lithium-ion battery is a part that significantly affects the performance of the battery. LiNiMnCoO2 (NMC) cathode, especially in the composition of LiNi0.8Mn0.1Co0.1O2 (NMC811), has high specific capacity but not high thermal and electrical conductivity stability. To improve the temperature stability and performance of the battery, conductive elements such as graphene can be added. The addition of graphene can increase battery performance due to its high electrical conductivity characteristics. In this study, the addition of graphene on NMC cathode through a simple solid-state technique along with direct mixing was shown to improve the cathode characteristics. The addition of graphene on the NMC cathode also proved to be capable of improving the cycle stability and rate capability. The retention capacity is 95.83 %, higher than that of the cathode without graphene modification, which is 92.27 % after 100 cycles with 1C current, and comparable to the capability of commercial batteries. The ability to work under rapid charge and discharge conditions was also well demonstrated with a capacity drop of 5.44 % over 200 cycles at a charge and discharge current of 5C. The addition of graphene was also shown to improve the safe use of NMC batteries. With the test at 5C current, the highest temperature of the battery was 46.52 °C, which is still considered safe for the operation of lithium ion-based batteries at high currents. In this research, the use of a simple solid-state method to mix the graphene with NMC811 cathode is proven to be able to produce lithium-ion batteries with superior performance. This offers ease in terms for use in large-scale production of cathode preparation that can produce high-performance cathodes.

Highlights The microstructure of graphite upon rapid Li+ intercalation is a mixture of differently staging structures in the macroscopic and microscopic scales due to the incomplete and inhomogeneous intercalation reactions hindered by the sluggish reaction kinetics. The Li+ interface diffusion dominates the reaction kinetics at high rates in thin graphite electrode, while Li+ diffusion through the electrode cannot to be neglected for thick graphite electrode.

To establish battery electric vehicles as an attractive alternative to internal combustion vehicles, charging times of 15 min or less are increasingly demanded. This is especially challenging for lower battery temperatures, as this exacerbates the risk of accelerated battery degradation due to lithium plating. Therefore, active battery heating is utilized in state-of-the-art electric vehicles. To evaluate the impact of such heating strategies at vehicle level, we deployed an electrochemical battery model coupled with a longitudinal vehicle dynamics model. Using anode potential control to prevent lithium plating, we assess the time-saving potential versus the energy cost of different preconditioning and fast-charging strategies. The results reveal substantial energy saving and charge speed increase potential through optimal charge-stop planning, preconditioning timing, cost-adjusted thermal management thresholds, and considering driving behavior. This emphasizes the need for advanced operation strategies, taking into account both battery-level electrical and thermal restrictions, as well as vehicle integration and route planning.

Highlights: The microstructure of graphite upon rapid Li+ intercalation is a mixture of differently staging structures in the macroscopic and microscopic scales due to the incomplete and inhomogeneous intercalation reactions hindered by the sluggish reaction kinetics. The Li+ interface diffusion dominates the reaction kinetics at high rates in thin graphite electrode, while Li+ diffusion through the electrode cannot to be neglected for thick graphite electrode. Fast-charging lithium-ion batteries are highly required, especially in reducing the mileage anxiety of the widespread electric vehicles. One of the biggest bottlenecks lies in the sluggish kinetics of the Li+ intercalation into the graphite anode; slow intercalation will lead to lithium metal plating, severe side reactions, and safety concerns. The premise to solve these problems is to fully understand the reaction pathways and rate-determining steps of graphite during fast Li+ intercalation. Herein, we compare the Li+ diffusion through the graphite particle, interface, and electrode, uncover the structure of the lithiated graphite at high current densities, and correlate them with the reaction kinetics and electrochemical performances. It is found that the rate-determining steps are highly dependent on the particle size, interphase property, and electrode configuration. Insufficient Li+ diffusion leads to high polarization, incomplete intercalation, and the coexistence of several staging structures. Interfacial Li+ diffusion and electrode transportation are the main rate-determining steps if the particle size is less than 10 μm. The former is highly dependent on the electrolyte chemistry and can be enhanced by constructing a fluorinated interphase. Our findings enrich the understanding of the graphite structural evolution during rapid Li+ intercalation, decipher the bottleneck for the sluggish reaction kinetics, and provide strategic guidelines to boost the fast-charging performance of graphite anode. [ABSTRACT FROM AUTHOR]

Demand for electric vehicles (EVs), and thus EV charging, has steadily increased over the last decade. Studies suggest that fast-charging facilities are crucial for the EV market. However, there is limited fast-charging infrastructure in most parts of the world to support EV travel, especially long-distance trips. The goal of this study is to develop a stochastic dynamic simulation modeling framework of a regional system of EV fast-charging stations for real-time management and strategic planning (i.e., capacity allocation) purposes. To model EV user behavior, specifically fast-charging station choices, the framework incorporates a multinomial logit station choice model that considers station charging prices, expected wait times, and detour distances. To capture the dynamics of supply and demand at each EV fast-charging station, the framework incorporates a multi-server queueing model in the simulation. The study assumes that multiple fast-charging stations are managed by a single entity (public or private) and that the demand for these stations are interrelated (through the station choice model). To manage the system of stations, this study proposes and tests dynamic demand-responsive price adjustment (DDRPA) schemes based on station queue lengths. The study applies the modeling framework to a system of EV fast-charging stations in Southern California. The computational results indicate that DDRPA strategies are an effective mechanism to balance charging demand across fast-charging stations. Specifically, compared to the no DDRPA scheme case, the quadratic DDRPA scheme reduces average wait time by 26%, increases charging station revenue (and user costs) by 5.8%, while, most importantly, increasing social welfare by 2.7% in the base scenario. Moreover, the study also illustrates that the modeling framework can evaluate the allocation of EV fast-charging station capacity, to identify stations that require additional chargers and areas that would benefit from additional fast-charging stations.

The most common pattern types for anode structuring, in particular the line, grid, and hexagonal-arranged hole pattern were evaluated in a comparable setup in full-cells and symmetrical cells. The cells with structured electrodes were compared to reference cells with unstructured anodes of similar areal capacity (4.3 mAh cm−2) and the onset of lithium plating during fast-charging was determined in situ by differential voltage analysis of the voltage relaxation and ex situ by post-mortem analysis. Furthermore, electrochemical impedance spectroscopy measurements on symmetrical cells were used to determine the ionic resistance of structured and unstructured electrodes of similar areal capacity. All cells with structured electrodes showed lower ionic resistances and an onset of lithium plating shifted to higher C-rates compared to cells with unstructured electrodes. The structure patterns with capillary structures, i.e., lines and grids, showed significant reduced lithium plating during fast-charging and a higher rate capability compared to reference cells with unstructured electrodes and cells with hole structured electrodes. The continuous rewetting of the electrode with liquid electrolyte by capillary forces and the reduced ionic resistance of the 3D electrode are identified as key factors in improving overall battery performance. The data of the studied cells were used to calculate the resulting energy and power densities of prospective commercial pouch cells and potential pitfalls in the comparison to cells with unstructured electrodes were identified.

Despite numerous research on new active materials for anodes, graphite remains the most commonly used material in Li-ion batteries. The spherical shape of the graphite particles has proven to be beneficial for application in electric vehicles, especially for fast charging. So far, the spheroidization of natural flake graphite is conducted by a rigid and inefficient cascade process. In this work, a scalable classifier system was used for spheroidization, and it was demonstrated that a spheroidization time of 15 min is sufficient to improve material properties and enhance electrochemical performance while maintaining high process yields of 55%. Insights into the influence of the morphology on the intrinsic and structural properties of the graphite particles and manufactured electrodes are provided. Spheroidization creates a more efficient pore network in the coating layer while reducing the internal resistance and increasing the surface area of the particles by a factor of 1.8. We demonstrate that the spherical shape improves the discharge rate capability by 1.8, and the specific charge capacity could be enhanced by more than 237% at a C-rate of 3. An additional carbon coating could significantly decrease the specific surface area and increase the specific capacity at high C-rates. [ABSTRACT FROM AUTHOR]

This paper proposes and analyzes a two-stage dc-dc isolated converter for electric vehicle charging applications, where high efficiency over a wide range of battery voltages is required. The proposed conversion circuit comprises a first two-output isolation stage with CLLC resonant structure and a second two-input buck regulator. The transformer of the first stage is designed such that its two output voltages correspond, ideally, to the minimum and maximum expected voltage to be supplied to the battery. Then, the second stage combines the voltages provided by the previous isolation stage to regulate the output voltage of the whole converter. The first stage is always operated at resonance, with the only function of providing isolation and fixed conversion ratios with minimum losses, whereas the second stage allows output voltage regulation over a wide range of battery voltages. Overall, it is shown that the solution features high conversion efficiency over a wide range of output voltages. This paper comprehensively describes the solution, including modeling, analyses, design considerations for the main circuit components (e.g., magnetics, switches), and modulation choices. Experimental results are reported considering a converter module prototype rated $10\,\mathrm{k}\mathrm{W}$, input voltage $800\,\mathrm{V}$, and output range $250\,\mathrm{V}$ to $500\,\mathrm{V}$, employing silicon-carbide and gallium-nitride semiconductors.

Power sources supported by lithium-ion battery (LIB) technology has been considered to be the most suitable for public and military use. Battery quality is always a critical issue since electric engines and portable devices use power-consuming algorithms for security. For the practical use of LIBs in public applications, low heat generation, and fast charging are essential requirements, but those features are still unsatisfactory so far. In particular, the slow Li+ intercalation kinetics, lithium plating, and self-heat generation of conventional graphite-anode LIBs under fast-charging conditions are impediments to the use of these batteries by the public demands. The use of silicon-based anodes, which are associated with fast reaction kinetics and rapid Li+ diffusion, has great potential to render LIBs suitable for public use in the near future. In this perspective, the challenges in and future directions for developing silicon-based anode materials for realizing LIBs with fast-charging capability are highlighted. [ABSTRACT FROM AUTHOR]

In this article, a new methodology for the sizing of a fast-charging station for electric vehicles is presented. The proposed method is applicable to public service vehicles on urban journeys. Its use has been conceived for vehicles equipped with an energy storage system based on supercapacitors (SCs), which are already functional in several countries. The proposed charging station also uses a bank of SCs of variable capacitance. During the study, mathematical expressions will be obtained for the electrical variables involved in vehicle charging: instantaneous current, peak current, charging time, dissipated energy, and the efficiency of energy transference. From these, each of the components of the system will be dimensioned: the capacitance of the charger with its different variable steps, the initial voltage of the charger, and the current smoothing inductor. The proposed charger presents the advantage of allowing energy to be evacuated to the electric vehicle very quickly and with high performance, all without using an external power source or high-power converters. The proposed architecture minimizes the disturbances that, with conventional methods, would appear on the electrical grid, preventing the installation of fast-charging stations at many grid nodes, as is currently the case. Finally, the charger control algorithm is considerably simplified as it only depends on the initial voltage of the vehicle's accumulator. [ABSTRACT FROM AUTHOR]

[Display omitted] High-energy-density lithium-ion batteries and sodium-ion batteries are two important rechargeable batteries in the large-scale electrochemical energy storage devices of modern society; however, the fast-charging of them, as one of the core technologies, is still not fully and adequately resolved, especially the correlated problems of the cathode side. This review highlights the key kinetically limiting factors in the process of fast-charging from the perspective of cathodic materials, and describes the various currently reported fast-charging cathode materials with improved rapid ions diffusion capability and fast reaction kinetics. Based on the energy-storage mechanism of cathode materials during fast-charging, a series of strategies, including nanostructure, doping and multiple-system, are discussed, while emphasis on the pseudocapacitive contribution in the battery type cathode materials for constructing the fast-charging lithium-ion batteries and sodium-ion batteries. [ABSTRACT FROM AUTHOR]

With the increasing popularity of electric/hybrid vehicles and the rapid development of 3C electronics, there is a growing interest in high-rate energy storage systems. The rapid development and widespread adoption of lithium-ion batteries (LIBs) can be attributed to their numerous advantages, including high energy density, high operating voltage, environmental friendliness, and lack of memory effect. However, the progress of LIBs is currently hindered by the limitations of energy storage materials, which serve as vital components. Therefore, there is an urgent need to address the development of a new generation of high-rate energy storage materials in order to overcome these limitations and further advance LIB technology. Niobium-based oxides have emerged as promising candidates for the fabrication of fast-charging Li-ion batteries due to their excellent rate capability and long lifespan. This review paper provides a comprehensive analysis of the fundamentals, methodologies, and electrochemistries of niobium-based oxides, with a specific focus on the evolution and creation of crystal phases of Nb2O5, fundamental electrochemical behavior, and modification methods including morphology modulation, composite technology, and carbon coating. Furthermore, the review explores Nb2O5-derived compounds and related advanced characterization techniques. Finally, the challenges and issues in the development of niobium-based oxides for high-rate energy storage batteries are discussed, along with future research perspectives.

Current research focuses on lithium-ion battery cells with a high energy density and efficient fast-charging capabilities. However, transport limitations, and, therefore, the uniform diffusion of lithium-ions across the electrode layers, remain a challenge and could lead to reduced cell performance. One approach to overcome these transport challenges is the use of subsequently produced two-layer anodes with the particle size variation of spherical graphite (x50 = 18 µm; x50 = 11 µm). Thereby, a defined pore network is created, which reduces the ionic resistance and ensuring improved fast charging capabilities. The analysis focuses on the evaluation of electrode properties and the electrochemical performance. By examining the pore size distribution of the anodes, it has been found that during the manufacturing of the two-layer anodes, carbon black and binder particles are transported into the existing microstructure of the lower layer, resulting in localized densification between the anode layers. This could also be supported by color measurements. This effect also extends to electrochemical investigations, with electrochemical impedance spectroscopy showing significantly lower ionic resistances in all two-layer anodes. Reduced ionic resistance and tortuosity near the separator due to absorption effects enhance the ion diffusion and have a direct impact on anode performance. Cell ageing analysis showed a significant capacity decrease of almost 15 mAh g −1 in the single-layer references only, in contrast to the stability of the two-layer anodes. This could also be attributed to the reduced ionic resistance and active counteraction of binder migration. In conclusion, this study highlights how subsequently produced two-layer anodes significantly shape the electrode properties and cell performance of lithium-ion batteries.

In this paper, an acrylate-modified binder is introduced to the negative electrode of a power battery to improve its fast-charging performance. The Li+ ionic conductivity of the acrylated-modified GD1346 copolymer was twice that of commercial SN307 copolymer at room temperature. GD1346 greatly reduced the Ohm resistance and charge transfer resistance of the negative electrode from those of SN307 and enhanced the surface potential to more than 15 mV. This high performance is attributed to strong electrolyte adsorption ability and the ester groups, which favour Li+ diffusion. Consequently, the fast-charging time of the power battery is reduced from 107 to 82 min as the state of charge increases from 0 to 100%. The practicality of acrylate-modified GD1346 binder in the manufacture of large-scale batteries is also confirmed. The techniques developed in this work are expected to promote the development of efficient binders for next-generation high-energy lithium ion batteries. [ABSTRACT FROM AUTHOR]

Intercalation-type metal oxides are promising active anode materials for the fabrication of safer rechargeable lithium-ion batteries, as they are capable of minimizing or even eliminating Li plating at low voltages. Due to the excellent cycle performance, high specific capacity and appropriate working potential, TiNb2O7 (TNO) is considered to be the candidate of anode materials. Despite a lot of beneficial characteristics, the slow electrochemical kinetics of the TNO-based anodes limits their wide use. In this paper, TiNb2O7@C was prepared by using the self-polymerization coating characteristics of dopamine to enhance the rate-performance and cycling stability. The TNO@C-2 particles present ideal rate performance with the discharge capacity of 295.6 mA h g−1 at 0.1 C. Moreover, the TNO@C-2 anode materials exhibit initial discharge capacity of 177.4 mA h g−1, providing 91% of capacity retention after 400 cycles at 10 C. The outstanding electrochemical performance can be contributed to the carbon layer, which builds fast lithium ion paths, enhancing the electrical conductivity of TNO. All these results confirm that TNO@C is a valid methodology to enhance rate-performance and cycling stability and is a new way to provide reliable and quickly rechargeable energy storage resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • The distinctions between Li+ diffusion paths of Li 3 VO 4 during fast-charging and slow-charging are well elucidated. • The lattice changes of Li+ insertion into different sites are predicted. • The work furnishes a theoretical basis for comprehending doping, nanosizing, and other modification methods. • The fast-charging issue could be addressed from atomic and lattice scales. "Fast-charging" lithium-ion batteries enjoy extensive attention as energy storage devices for portable electronic devices and new energy vehicles. Regrettably, high safety could not be effectively ensured while the batteries undergo fast-charging process. Li 3 VO 4 could be recognized as a high-safety "fast-charging" anode material considering its appropriate Li-insertion voltage and fast kinetic characteristics. Currently, notwithstanding the fact that Li 3 VO 4 has been extensively investigated as an anode material for lithium-ion batteries and the encouraging research results have been accomplished, the distinction between ion diffusion mechanisms during fast-charging and slow-charging has not been well elucidated. Unlike previous reports, Li+ fast/slow diffusion mechanisms in Li 3 VO 4 are investigated in detail in this work. Specifically, Li+ tends to diffuse along path a due to rather fast Li-insertion/deinsertion processes. Correspondingly, Li+ undergoes diffusion along path a and path b during slow-charging. Unlike the conventional view that Li+ prefers to diffuse along path a under all conditions. Additionally, the lattice changes of Li+ insertion into different sites are predicted. The findings could facilitate to comprehend the mechanism of doping, nanosizing, and other modification methods, and the fast-charging issue could be addressed in a targeted way. For instance, the optimal fast diffusion paths are modified at both atomic and lattice scales, inducing that Li+ could be inserted into the lattice of material faster during fast-charging and the power densities could be increased. Accordingly, understanding the fast diffusion mechanism of Li+ in Li 3 VO 4 is crucial to addressing the "fast-charging" of these materials. Unfortunately, the inferior electronic conductivity restricts its Li-storage capacity in "fast-charging" devices. Herein, a Li 3 VO 4 based anode material is prepared thorough a one-step hydrothermal method and liquid-phase dispersion technique in the existence of polyvinyl pyrrolidone, which demonstrates exceptional discharging and charging specific capacities, maintaining 273 mAh g−1 at 0.1 A g−1. It also presents considerably higher "fast-charging" performance even at 1.0–4.0 A g−1. Electrochemical kinetic studies indicate that the thin coating could improve the conductivity of Li 3 VO 4. The Li-insertion sites and diffusion paths during fast-charging and slow-charging processes are predicted computationally. And the in-situ XRD is adopted to insight into the structural changes of composites during Li-insertion/deinsertion processes. The data furnishes a theoretical basis for comprehending the fast lithium storage mechanism of Li 3 VO 4 and offers a new method for searching for "fast-charging" anode materials. [ABSTRACT FROM AUTHOR]

The nanohybrid of CoSe 2 -NiSe 2 heterojunction and HrGO was synthesized via combining thermal etching and in-situ selenization strategy. The holey reduced graphene oxide (HrGO) enabling rapid Na+ diffusion along this direction. CoSe 2 -NiSe 2 heterojunction creates an internal electric field, which leads to a rapid electrochemical reaction kinetic at the heterojunction interface. The incorporation of HrGO with CoSe 2 -NiSe 2 heterojunctions synergistically enhances both external and internal charge transfer rate, thereby improving the fast-charging performance of SIBs. [Display omitted] • The nanohybrid of CoSe 2 -NiSe 2 and HrGO is synthesized via combining thermal etching and in-situ selenization strategy. • The Na+ storage mechanism was well revealed by using the in-situ/ex-situ characterizations and DFT calculations. • These features contribute to excellent rate performance (392.4mAh/g at 15 A/g) and competitive cycling stability. • The synergistic effect o'f the nanoporous structure in HrGO and CoSe 2 -NiSe 2 heterostructure can improve Na+ transport rate. Inspired by the "Barrel principle" and based on the working principle of the "rocking chair". We propose two shortboards that "bulk diffusion rate" and "ion reaction rate", which affect the fast charging of sodium ion batteries (SIBs). The holey reduced graphene oxide (HrGO) with abundant nanopores provides longitudinal diffusion channels, enabling rapid Na+ diffusion along this direction, which solves the shortboard of bulk diffusion rate. Additionally, heterojunctions are considered a viable approach for enhancing fast Na+ storage performance by providing more storage sites and accelerating the kinetics of Na+ reaction, which solve the shortboard of ion reaction rate. Herein, we construct HrGO combined with CoSe 2 -NiSe 2 heterojunctions has been rationally fabricated to synergistically enhance the ionic and electronic diffusion kinetics. As expected, the CoSe 2 -NiSe 2 /HrGO anode in SIBs shows an excellent fast-charging performance (392.4mAh/g at 15 A/g), surpassing most Co/Ni-based selenide anodes. Additionally, the assembled CoSe 2 -NiSe 2 /HrGO||NVP full cell delivers a high specific capacity of 116.1 and 95.4mAh/g at 0.1 and 20C, respectively, coupled with 97.8 % capacity retention rate for 100 cycles. Furthermore, we elucidate the mechanism of Na+ storage and fast transport through electrochemical kinetic analysis, in situ and ex situ characterizations, density functional theory (DFT) calculations, and distribution of relaxation times (DRT). Importantly, this study provides theoretical insights into accelerating rapid Na+ transfer. [ABSTRACT FROM AUTHOR]

Vanadium sulfide is considered a promising electrode material for achieving rapid lithium storage ascribing to its high specific capacity, unique crystal structure, and abundant valence states. Unfortunately, the structural collapse induced by volume expansion during charging and discharging is the key factor affecting rapid lithium storage. This article prepares composite materials with different morphologies through a strategy of decorating vanadium sulfide at carbon matrix. Among them, graphene oxide modified vanadium tetrasulfide composite materials with three-dimensional conductive networks exhibit excellent electrochemical performance. When the current density is 50 mA g−1, the discharging specific capacity reaches 1, 560 mAh g−1. After 2, 500 cycles at a high current density of 10, 000 mA g−1, the specific capacity is about 188 mAh g−1 with charging time of approximately 70 s. GITT testing indicates that the order of magnitude of the logarithm of the initial diffusion coefficient is 10−11 cm2 s−1 owing to the three-dimensional porous conductive network, which not only shortens ion diffusion path but also provides more active sites for lithium-ion storage, rendering it a promising anode material for "fast-charging" lithium-ion batteries. [Display omitted] • Vanadium sulfide modified with graphene oxide composite materials. • Electrode materials showing a three-dimensional porous conductive network. • The materials structure is beneficial for "fast- charging" lithium-ion batteries. • Exhibiting approximately 188 mAh g-1 after 2, 500 cycles at 10, 000 mA g-1. [ABSTRACT FROM AUTHOR]

Bismuth is considered to be a promising anode for sodium-ion batteries due to its low voltage plateau and high volumetric capacity. However, the large volume variation during alloying/dealloying leads to electrode pulverization and performance degradation, especially under high current densities. Herein we propose a lattice-confined localized alloying reaction mechanism to solve the above issues. By chemically embedding Bi atoms in a rigid layered ▪ host framework, the alloying reaction of Bi is spatially and kinetically confined within the ▪ interlayer, allowing for complete recovery of the Bi 0.67 TaS 2 crystal structure after desodiation. The as-prepared Bi 0.67 TaS 2 anode exhibits superior rate performance, achieving capacities of 256 mAh g ▪ at 1 C and 186 mAh g ▪ at 150 C, along with remarkable long-term cycling stability for maintaining 153 mAh g ▪ after 20000 cycles at 150 C. This work demonstrates that the localized alloying mechanism enabled by lattice confinement significantly contributes to both rate and cycling performance, which is expected to provide insights into electrode design for future fast-charging batteries. • A new Bi 0.67 TaS 2 anode is designed via chemically integrating electrochemical-active atomic Bi and 2D TaS 2 host framework. • Bi 0.67 TaS 2 undergoes a reversible electrochemical reaction with its crystalline phase being recovered after recharging. • A lattice-confined localized alloying mechanism is proposed. • Bi 0.67 TaS 2 exhibits superior rate performance up to 150 C and long-term cycling stability for 20,000 cycles. [ABSTRACT FROM AUTHOR]

In the quest for high-energy-density lithium metal batteries (LMBs), the stabilization of lithium (Li) metal anodes during fast charging remains a formidable challenge. In this study, a novel copolymer, Poly(methyl methacrylate- co -styrene) (namely PMS) is synthesized and blended with Poly(vinylidene fluoride) to fabricate a porous gel polymer electrolyte (GPE, namely PMS-PVDF) through the nonsolvent-induced phase separation technique, which significantly enhances the electrochemical stability and fast-charging capabilities of LMBs. The developed GPE exhibits a high ionic conductivity of 5.62 mS cm−1, thereby reducing the formation of detrimental Li dendrites and leading to over 400 h stripping/plating process at 0.5 mA cm−2. Extensive electrochemical tests show that the LMBs with the obtained PMS-PVDF GPE achieve exceptional cycle stability over 600 and 1000 cycles at the C-rates of 0.5 and 3 C, respectively, outperforming traditional electrolytes. Furthermore, the ultra-stability of the quasi-solid-state electrolyte is demonstrated in a 375 mAh pouch cell setup, suggesting an essential trait for the practical application of high-power devices. This work marks a pivotal contribution to the field of energy storage, delivering insights and a clear methodology that pave the way for the development of next-generation LMBs poised for commercial viability. [Display omitted] • Synthesized PMS-PVDF polymer matrix enhances GPE porosity via NIPS method. • GPE achieves 5.62 mS/cm ionic conductivity, effectively suppressing dendrite growth. • Li//LFP cells with GPE exhibit stable cycling across various C-rates. • LMBs deliver 106.5 mAh/g at 10 C, showcasing excellent rate performance. [ABSTRACT FROM AUTHOR]

SiO-based materials represent a promising class of anodes for lithium-ion batteries (LIBs), with a high theoretical capacity and appropriate and safe Li-insertion potential. However, SiO experiences a large volume change during the electrochemical reaction, low Li diffusivity, and low electron conductivity, resulting in degradation and low rate capability for LIBs. Here, we report on the rapid crafting of SiO–Sn2Fe@C composites via a one-step plasma milling process, leading to an alloy of Sn and Fe and in turn refining SiO and Sn2Fe into nanoparticles that are well dispersed in a nanosized, few-layer graphene matrix. The Sn and Fe nanoparticles generated during the first Li-insertion process form a stable network to improve Li diffusivity and electron conductivity. As an anode material, the SiO–Sn2Fe@C composite manifests high reversible capacities, superior cycling stability, and excellent rate capability. The capacity retention is found to be as high as 95% and 84% at the 100th and 300th cycles under 0.3 ​C. During rate capability testing at 3, 6, and 11 ​C, the capacity retentions are 71%, 60%, and 50%, respectively. This study highlights that this simple, one-step plasma milling strategy can further improve SiO-based anode materials for high-performance LIBs.

Fast Charging Station (FCS) is required to reduce charging time of electric vehicle, electric bus, or electric trucks. However, FCS requires high amount of power to support charging a large number of vehicles in reduced time. To reduce the load on the grid and lower the emission of greenhouse gas (GHG), renewable energy sources (RESs) are the most promising option. Renewable energy sources are intermittent, and the penetration of renewable energy sources are restricted by the area and the capacity of the charging station. To address this issue, a micro modular reactor that acts as a small nuclear power plant is introduced to support the RESs and minimize GHG emissions. The proposed Nuclear-Renewable Hybrid Energy System (N-R HES) is compared with different energy systems such as standalone diesel generator-based systems, conventional diesel generators integrated with RESs, standalone small nuclear power plants, in terms of greenhouse gas emission, cost of energy, net present cost, and return on investment to analyze the feasibility of the N-R HES. Sensitivity analysis is performed to assess the technical and economic aspects of the proposed system, where results show that the N-R HES can be a reliable option for sustainable energy solutions and decarbonization.

Abstract High-energy–density lithium-ion batteries (LIBs) that can be safely fast-charged are desirable for electric vehicles. However, sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density. Here we hypothesize that a cobalt vanadate oxide, Co2VO4, can be attractive anode material for fast-charging LIBs due to its high capacity (~ 1000 mAh g−1) and safe lithiation potential (~ 0.65 V vs. Li+/Li). The Li+ diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15 × 10–10 cm2 s−1, proving Co2VO4 a promising anode in fast-charging LIBs. A hexagonal porous Co2VO4 nanodisk (PCVO ND) structure is designed accordingly, featuring a high specific surface area of 74.57 m2 g−1 and numerous pores with a pore size of 14 nm. This unique structure succeeds in enhancing Li+ and electron transfer, leading to superior fast-charging performance than current commercial anodes. As a result, the PCVO ND shows a high initial reversible capacity of 911.0 mAh g−1 at 0.4 C, excellent fast-charging capacity (344.3 mAh g−1 at 10 C for 1000 cycles), outstanding long-term cycling stability (only 0.024% capacity loss per cycle at 10 C for 1000 cycles), confirming the commercial feasibility of PCVO ND in fast-charging LIBs.

ChargEVal is a framework for simulating the performance of charging station deployment scenarios using agent-based modelling (ABM). The ABM utilizes behavioural models for simulating vehicle choice for the trip and charging choice during a trip. ChargEVal can be used by several users to submit multiple simulations simultaneously, using a graphical user interface or programmatically. ChargEVal also has a dedicated results viewer for viewing the simulation summary statistics and agent state values, facilitating detailed insight and simulation comparison. While the current implementation of ChargEVal is specific to the State of Washington, USA; the underlying framework is generic enough to be applied to any geography at any scale.

This article proposes and analyzes a two-stage isolated dc–dc converter for electric vehicle charging applications, where high efficiency over a wide range of battery voltages is required. It employs a first preregulation stage and a second half-bridge LLC stage, integrated with the first. The second stage is always operated at resonance, ensuring high efficiency. The first preregulation stage is responsible for the desired input-to-output voltage conversion ratio and the zero-voltage switching operation of all the switches. This allows low conversion losses even with voltages that may vary over a wide range. The article presents the conversion structure, the converter analysis, the design of the magnetic elements, and demonstrates the converter operation considering an experimental prototype interfacing a ${750\text{-}} \mathrm{V}$ dc-link with an output bus with nominal voltage range ${250} \mathrm{}$ – ${500}\, \mathrm{V}$. The implemented module is rated ${5}\,\text{kW}$ and achieves a peak efficiency of $\boldsymbol{98.0\%}$ at ${3\text{-}} \text{kW}$ output power. [ABSTRACT FROM AUTHOR]

Despite numerous research on new active materials for anodes, graphite remains the most commonly used material in Li-ion batteries. The spherical shape of the graphite particles has proven to be beneficial for application in electric vehicles, especially for fast charging. So far, the spheroidization of natural flake graphite is conducted by a rigid and inefficient cascade process. In this work, a scalable classifier system was used for spheroidization, and it was demonstrated that a spheroidization time of 15 min is sufficient to improve material properties and enhance electrochemical performance while maintaining high process yields of 55%. Insights into the influence of the morphology on the intrinsic and structural properties of the graphite particles and manufactured electrodes are provided. Spheroidization creates a more efficient pore network in the coating layer while reducing the internal resistance and increasing the surface area of the particles by a factor of 1.8. We demonstrate that the spherical shape improves the discharge rate capability by 1.8, and the specific charge capacity could be enhanced by more than 237% at a C-rate of 3. An additional carbon coating could significantly decrease the specific surface area and increase the specific capacity at high C-rates.

Battery design has important effects on its fast-charging performance. This research took a prismatic NMC lithium-ion cell as the object, and built its finite element model based on the electrochemical and thermal theories. The voltages during the 1C, 3C, and 6C charging processes were obtained and compared with the experiment results, which verified the effectiveness of the model. By changing the structure parameters and material parameters of the cell, their influence on the fast-charging capability of the cell was systematically investigated. The structure parameters included the active layer thickness, cell balance, and separator thickness. The material parameters included the particle radii in the positive electrode and negative electrode, the porosities of the positive active layer, negative active layer, and separator. It was found that most of them would influence the fast-charging capability of the cell distinctly, except for the cell balance. Compared with others, the porosities of the positive active layer, negative active layer, and separator had the most significant influence on the fast-charging capability of the cell. And the smaller the porosities were, the greater the influence was. The conclusions obtained could provide references for the structure design and material design of lithium-ion batteries toward fast-charging technology. [ABSTRACT FROM AUTHOR]

Efficient fast-charging technology is necessary for the extension of the driving range of electric vehicles. However, lithium-ion cells generate immense heat at high-current charging rates. In order to address this problem, an efficient fast charging–cooling scheduling method is urgently needed. In this study, a liquid cooling-based thermal management system equipped with mini-channels was designed for the fast-charging process of a lithium-ion battery module. A neural network-based regression model was proposed based on 81 sets of experimental data, which consisted of three sub-models and considered three outputs: maximum temperature, temperature standard deviation, and energy consumption. Each sub-model had a desirable testing accuracy (99.353%, 97.332%, and 98.381%) after training. The regression model was employed to predict all three outputs among a full dataset, which combined different charging current rates (0.5C, 1C, 1.5C, 2C, and 2.5C (1C = 5 A)) at three different charging stages, and a range of coolant rates (0.0006, 0.0012, and 0.0018 kg·s−1). An optimal charging–cooling schedule was selected from the predicted dataset and was validated by the experiments. The results indicated that the battery module’s state of charge value increased by 0.5 after 15 min, with an energy consumption lower than 0.02 J. The maximum temperature and temperature standard deviation could be controlled within 33.35 and 0.8 °C, respectively. The approach described herein can be used by the electric vehicles industry in real fast-charging conditions. Moreover, optimal fast charging–cooling schedule can be predicted based on the experimental data obtained, that in turn, can significantly improve the efficiency of the charging process design as well as control energy consumption during cooling.

Nowadays solid‐state lithium metal batteries (SSLMBs) catch researchers’ attention and are considered as the most promising energy storage devices for their high energy density and safety. However, compared to lithium‐ion batteries (LIBs), the low ionic conductivity in solid‐state electrolytes (SSEs) and poor interface contact between SSEs and electrodes counteract some advantages of SSEs. As a result, SSLMBs show high energy density but low critical current density and slow charging speed. Herein, the recent progress and proposed strategies for fast‐charging SSLMBs are reviewed. In the second part of this review, various strategies for improving SSE performance in fast‐charging batteries are comprehensively highlighted. In the third part, various rational structure design schemes benefitting fast‐charging batteries are discussed. Finally, the development of fast‐charging SSLMBs is concluded and prospected. It is believed that the combination of fast‐charging times and SSLMBs is rather competitive for next‐generation, high energy density, high safety, and high charging rate energy storage devices.

We report an environmentally benign recycling approach for large-capacity nickel manganese cobalt (NMC) batteries through the electrochemical concentration of lithium on the anode and subsequent recovery with only water. Cycling of the NMC pouch cells indicated the potential for maximum lithium recovery at a 5C charging rate. The anodes extracted from discharged and disassembled cells were submerged in deionized water, resulting in lithium dissolution and graphite recovery from the copper foils. A maximum of 13 mg of lithium salts per 100 mg of the anode, copper current collector, and separator was obtained from NMC pouch cell cycled at a 4C charging rate. The lithium salts extracted from batteries cycled at low C-rates were richer in lithium carbonate, while the salts from batteries cycled at high C-rates were richer in lithium oxides and peroxides, as determined by X-Ray photoelectron spectroscopy. The present method can be successfully used to recover all the pouch cell components: lithium, graphite, copper, and aluminum current collectors, separator, and the cathode active material. • Lithium recovery by electrochemical concentration in 250 mA H NMC batteries. • Li selectively recovered from anode surface using only water, at room temperature. • Cathode material, current collectors, graphite, and separator are also recovered. • Recovered Li product depends on charging rates during electrochemical concentration. [ABSTRACT FROM AUTHOR]

[Display omitted] • The morphology of the graphite particles is a key to determine the pore structure of dry-processed graphite electrode for lithium-ion batteries. • PTFE based dry processed electrodes with spherical graphite particles have greater porosity-gradient structure than those with flake-type graphite particles. • Dry processed electrodes with greater porosity-gradient showed much lower ionic resistance and tortuosity than wet-processed electrodes. • Dry processed electrodes with spherical graphite showed much improved fast-charging capability. Improving lithium-ion transport in electrodes by controlling electrode microstructure is a promising option for enhancing the fast-charging capability of graphite anodes in lithium-ion batteries. Dry processing of electrodes based on a polytetrafluoroethylene binder has attracted considerable attention as an alternative to solvent-based wet processing. The morphology of graphite particles has a significant impact on electrode microstructure, but few reports have been published on dry-processed graphite anodes. In this work, we found that the morphology of graphite particles is a key factor to determine the fast-charging capability of the dry-processed graphite electrode as well as the microstructure of the dry-processed graphite electrode. X-ray microscopy combined with mercury porosimetry and symmetrical cell electrochemical impedance spectroscopy reveal that the difference in porosity between the top and bottom layers of a dry electrode with spherical graphite particles is greater than that of flake-shaped graphite particles, resulting in enhanced lithium-ion transport in the electrode and improved fast-charging capability at a high charging rate of 5C (17.5 mA cm−2). These findings supply insights into the effective design of dry-processed graphite anodes with an emphasis on fast-charging capability as well as the development of graphite anode materials for dry-processing based lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Developing fast-charging lithium metal battery (LMB) with high specific capacity arouses enormous attentions. Unfortunately, during the operation of fast-charging LMB, substantial amount of Joule heat generated within battery often induces inhomogeneous heat accumulation that concomitantly deteriorates the lithium dendrite growth issues, resulting in rapid capacity fading and potentially fatal thermal runaway. It is critically essential to develop advanced separator that possesses high ionic conductivity, effective dendrite inhibition and self-extinguishing property for fast-charging LMB with high-safety. Here, we report a facile approach to fabricate polyimide composite separator (denoted as PIFAP), where the polyimide fiber (PIF) membrane is sandwiched by aerogel layers of polyimide/ammonium polyphosphate composite. Notably, compared with PIF, the PIFAP features significant enhancement in flame retardance, electrolyte affinity, electrolyte adsorption and ionic conductivity. Moreover, beneficiating from the aerogel layers with uniform nanopores of ∼100 nm, the optimized PIFAP separator can enable homogeneous lithium deposition, achieving a dendrite-free lithium deposition on the surface of anode for over 1600 h, superior to the PIF and Celgard separators. The resulting "LiFePO 4 /PIFAP/Li" cell can exhibit a remarkably high cycling stability with 99.1 % of capacity retention after long-term cycling at a current density of 10 C. • A self-extinguishing polyimide sandwiched separator (denoted as PIFAP) is prepared. • The PIFAP separator can enable uniform Li deposition for 1600 h at 5 mA/cm2. • The Li-metal batteries with PIFAP separator exhibit remarkable stability at 10 C. [ABSTRACT FROM AUTHOR]