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Perovskite fluorides are attractive anode materials for lithium-ion batteries (LIBs) because of their three-dimensional diffusion channels and robust structures, which are advantageous for the rapid transmission of lithium ions. Unfortunately, the wide band gap results in poor electronic conductivity, which limits their further development and application. Herein, the cubic perovskite iron fluoride (KFeF3, KFF) nanocrystals (∼100 nm) are synthesized by a one-step solvothermal strategy. Thanks to the good electrical conductivity of carbon nanotubes (CNTs), the overall electrochemical performance of composite anode material (KFF-CNTs) has been significantly improved. In particular, the KFF-CNTs deliver a high specific capacity (363.8 mAh g−1), good rate performance (131.6 mAh g−1 at 3.2 A g−1), and superior cycle stability (500 cycles). Note that the surface conversion reactions play a dominant role in the electrochemical process of KFF-CNTs, together with the stable octahedral perovskite structure and nanoscale particle sizes achieving high ion diffusion coefficients. Furthermore, the specific lithium storage mechanism of KFF has been explored by the distribution of relaxation times technology. This work opens up a new way for developing cubic perovskite fluorides as high-capacity and robust anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Owing to its higher earth element reserve and similar chemical properties to lithium, potassium ion batteries (PIBs) have been regarded as a potential alternative to lithium-ion batteries. And considering the relatively larger ionic radius of potassium, available electrode materials need to be equipped with enough space for volume expansion during charge–discharge cycles, thus graphitic carbon nanomaterials with adjustable layer spacing gradually come into researcher's version. Here with copper nanowires serving as growth template and organic polyvinyl pyrrolidone (PVP) providing carbon source, freestanding and ultra-light graphitic carbon nanotube (GCNT) aerogels were simply assembled and annealed, which were directly used as anodes of PIBs. Annealing parameters (temperature and atmosphere) were adapted to regulate the lattice order and interlayer spacing of GCNTs, and N, O heteroatoms derived from PVP were directly doped into the carbon lattice during thermal annealing, to optimize and enhance the cycle capacity and rate performance of GCNT anodes. The electrochemical potassium storage mechanism of GCNTs was also quantitatively analyzed. Most of the potassium ions are reversibly stored by squeezing into and escaping from the carbon lattice, and simultaneously oxygen-containing functional groups with different chemical states also offer active redox sites and dedicate partial capacity. Therefore, our assembled GCNTs with large lumen are expected to sandwich-like load with active substances efficiently, further constructing next-generation PIBs with excellent performance. [ABSTRACT FROM AUTHOR]

The present work emphases on the post-mortem study of silica/carbon composite as functional anode in Li-ion batteries (LIBs). Herein, the silica/carbon composite is synthesized by facile in-situ hydrothermal technique. The x-ray diffraction (XRD) pattern indicates the amorphous nature of silica/carbon composite. The stacked sheet-like morphology of silica/carbon composite is seen in the high-resolution transmission electron microscopy (HR-TEM) & scanning electron microscopy (SEM) images. In addition, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray analysis (EDAX), and x-ray photoelectron spectra (XPS) characterizations of silica/carbon composite has been studied in detail. The rate capability of silica/carbon composite anode in LIB indicates 99% capacity retention after applying current density ranging from 50 mA g−1 to 1000 mA g−1, successively. The composite anode delivers a stable specific capacity ∼300 mAh g−1 at a current density of 100 mA g−1 for 500 cycles. Electrochemical impedance spectroscopy (EIS) study analyzed the faster Li-ion diffusion and increment in the diffusion coefficient by a factor of 1000 after 500 cycles. To the best of our knowledge, this is the first work on the post-mortem study of silica/carbon composite as anode in LIB. Post-cycling characterizations including XRD, FTIR, and SEM reveal the absence of any impurity phases and negligible volumetric expansion after prolonged cycling. It further confirms that the carbon present in the silica/carbon composite helps to accommodate the volumetric expansion of silica and prevents cracking of the anode over 500 cycles. [ABSTRACT FROM AUTHOR]

Molybdenum dioxide (MoO2) is regarded as a potential anode for lithium-ion batteries due to its highly theoretical specific capacity. However, its further application in lithium-ion battery is largely limited by insufficient practical discharge capacity and cyclic performance. Here, MoO2 nanoparticles are in-situ grown on three-dimensional nitrogen doped carbon nanotubes (NCNTs) on nickel foam substrate homogeneously using a simple electro-deposition method. The unique structural features are favorable for lithium ions insertion and extraction and charge transfer dynamics at electrode/electrolyte interface. As a proof of concept, the as-synthesized nanocomposites have been employed as anode for lithium-ion battery, exhibiting a reversible and significantly improved discharge capacity of ∼517 mA h g−1 at the current density of 150 mA g−1 as well as superior cycle and rate performance. The first-principle calculations based on density functional theory and electrochemical impedance spectroscopy results demonstrate a reduced energy barrier of lithium ions diffusion, improved lithium storage behavior, reduced structure collapse, and significantly enhanced charge transfer kinetics in MoO2/NCNTs nanocomposites with respect to MoO2 powder. The excellent performance makes as-prepared MoO2/NCNTs nanocomposites promising binder-free anode for high performance lithium-ion batteries. This work also provides important theoretical insights for other state-of-the-art batteries design. [ABSTRACT FROM AUTHOR]

With the growing prevalence of neuromorphic computing algorithms, there is a growing need for electronic synaptic devices. In this study, using Li4+ x Ti5O12 (LTO) as the resistive switching layer, C as the lithium ions storage layer, and Li1+ x Al x Ti2− x (PO4)3 (LATP) as ions transmission layer, a synaptic device is designed with the structure of Pt/C/LATP/LTO/PtSi to imitate the lithium-ion battery. Variation of the thickness of the LATP layer in the LTO device is explored to show the impact on the device's synaptic performance. With a LATP thickness of 100 nm, the LTO synaptic device exhibits a high potentiation/depression cyclic stability of over 50 cycles, improved potentiation/depression linearity and smoothness. The synaptic potentiation/depression is ascribed to migration of lithium ions from the LTO layer. A conductance relaxation characteristic of the device is explained by battery self-discharge phenomenon. The battery effect in the LTO device also led to generation of electromotive force. The study of battery-imitating LTO synaptic device offers new perspectives on the connection between battery and analog synaptic device. [ABSTRACT FROM AUTHOR]

A variety of strategies have been developed to enhance the cycling stability of Si-based anodes in lithium-ion batteries. Although significant progress has been made in enhancing the cycling stability of Si-based anodes, the low initial Coulombic efficiency (ICE) remains a significant challenge to their commercial application. Herein, pitch-based carbon (C) coated Si nanoparticles (NPs) were wrapped by graphene (G) to obtain Si@C/G composite with a small specific surface area of 11.3 m2 g−1, resulting in a high ICE of 91.2% at 500 mA g−1. Moreover, the integrated utilization of graphene and soft carbon derived from the low-cost petroleum pitch strongly promotes the electrical conductivity, structure stability, and reaction kinetics of Si NPs. Consequently, the synthesized Si@C/G with a Si loading of 54.7% delivers large reversible capacity (1191 mAh g−1 at 500 mA g−1), long cycle life over 200 cycles (a capacity retention of 87.1%), and superior rate capability (952 mAh g−1 at 1500 mA g−1). When coupled with a homemade LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode in a full cell, it exhibits a promising cycling stability for 200 cycles. This work presents an innovative approach for the manufacture of Si-based anode materials with commercial application. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have revolutionized portable electronics, yet their conventional graphite anodes face capacity limitations. Integrating graphene and 3D molybdenum disulfide (MoS2) offers a promising solution. Ensuring a uniform distribution of 3D MoS2 nanostructures within a graphene matrix is crucial for optimizing battery performance and preventing issues like agglomeration and capacity degradation. This study focuses on synthesizing a uniformly distributed paper wad structure by optimizing a composite of reduced graphene oxide RGO@MoS2 through structural and morphological analyses. Three composites with varying graphene content were synthesized, revealing that the optimized sample containing 30 mg RGO demonstrates beneficial synergy between MoS2 and RGO. The interconnected RGO network enhances reactivity and conductivity, addressing MoS2 aggregation. Experimental results exhibit an initially superior capacity of 911 mAh g−1, retained at 851 mAh g−1 even after 100 cycles at 0.1 A g−1 current density, showcasing improved rate efficiency and long-term stability. This research underscores the pivotal role of graphene content in customizing RGO@MoS2 composites for enhanced LIB performance. [ABSTRACT FROM AUTHOR]

This study presents a novel method for implementing internal temperature sensors in cylindrical lithium-ion batteries by laser ablation to enhance the understanding of thermal runaway (TR) behavior. Using commercial 21700 cells, Accelerating Rate Calorimetry (ARC) experiments were conducted at various states of charge. The results showed that internal temperature changes during safety-critical events, such as venting and TR, were significantly higher compared to externally measured cell surface temperatures. [ABSTRACT FROM AUTHOR]

Batteries are the cornerstone of the global shift toward electrification, powering applications from passenger transportation, like electric vehicles (EVs), to load shifting of renewable energy generation at the grid level. The demand for batteries is accelerating, and is projected to nearly quadruple by 2030. In response to increasing battery demands, in particular demand for longer range EVs, higher energy density and specific energy alternatives to conventional Li-ion battery technologies are being researched. However, higher energy density directly correlates with an increased potential for higher peak temperatures on failure. In addition, safety evaluation of conventional and new battery technologies generally occurs late in development, often at the commercialization stage when mandated by stakeholders or industry standards. This approach can be costly and challenging as it may require a change to manufacturing processes, a re-design of the battery, and even a change in chemistry to meet safety requirements. This is critical; scale-up efforts alone can take tens to hundreds of millions of dollars and >5 years to achieve. Safety risks discovered after commercialization can significantly exacerbate those figures. Furthermore, safety is still a major risk with already commercialized Li-ion batteries. These risks hinder adoption, slow commercialization, and when they become issues, the outcome may result in recalls, fires, injuries, and even fatalities. Providing additional levers to proactively mitigate safety risk at the materials and components scale (e.g., composite cathode) will lead to considerable time and money savings in the long run. [ABSTRACT FROM AUTHOR]

The thermal safety of lithium-ion batteries has garnered significant attention due to its pivotal role in the field of new energy. In this work, a three-dimensional electrochemical-thermal coupling model based on the P2D model was established for predicting the thermal performance. The charge-discharge and temperature rise experiments via 18650 cylindrical Li[Ni0.6Co0.2Mn0.2]O2 / graphite batteries are designed to confirm the rationality of the model. The simulation results show that the highest temperature of the battery surface during discharging at 1 C and 4 C are 42.85 °C and 61.25 °C, and the experimental results are 42.50 °C and 62.85 °C, respectively. The electrode heat generation mainly comes from the reaction heat of cathode and anode during 1 C charge process, the maximum power is 1.2 W and 0.6 W, respectively. In the discharge process, the cathode dominates the reaction contribution of 1.02 W and the reaction heat power from the anode is only 0.016 W. The capacity of heat dissipation can be increased by enhancing the convective heat transfer coefficient and air velocity within a reasonable range. The proposed electrochemical-thermal coupling model is valuable to evaluate the heat behavior and promote the battery development. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries content complex internal components, such as porous media and electrolytes, which result in strong scattering and high attenuation of ultrasonic waves in these batteries. The low attenuative feature of the quasi-static components (QSCs) of ultrasonic waves offers great potential for nondestructive assessment of highly attenuating and porous materials. This paper presents an innovative approach for estimating the state-of-charge (SOC) of lithium-ion batteries using QSC of ultrasonic waves. Experimental results demonstrate a clear and repeatable linear relationship between the amplitudes of the generated QSC and the SOC of lithium-ion batteries. In addition, the relationships between different SOCs of the battery and the conventional linear ultrasonic parameters, second harmonic generation (SHG), and the QSC were compared to verify the improved sensitivity of the proposed approach. Notably, compared to linear ultrasonic features and the SHG, the generated QSC shows much higher sensitivity to the variations of SOC. We employ the phase-reversal method to further enhance the signal-to-noise ratio of measured QSC signals. The experimental results demonstrate that the proposed method exhibits a heightened sensitivity to changes in the SOC of batteries, resulting in significantly enhanced detection accuracy and resolution. This method effectively addresses the deficiencies observed in the current detection methods such as limited accuracy and sluggish response times. This method provides a new solution to overcome this challenge. Meanwhile, it also confirms that nonlinear ultrasound promises an alternative method for SOC assessment, providing a foundation for efficient and safe battery management practices. [ABSTRACT FROM AUTHOR]

The massive volume dilation, unsteady solid electrolyte interphase, and weak conductivity about Si have failed to bring it to practical applications, although its potential capacity is up to 4200 mAh g−1. For solving these problems, novel binary regulated silicon–carbon materials (Si/BPC) were done by a sol–gel procedure combined with single carbonization. Analytical techniques were systematically utilized to examine the effects of element doping at several gradients on morphology, structure and electrochemical properties of composites, thus the optimal content was identified. Si/BPC preserves a discharge specific capacity of 1021.6 mAh g−1 with a coulomb efficiency of 99.27% after 180 cycles at 1000 mA g−1, within the upgrade than single-doped and undoped. In rate test, it has a specific capacity of 1003.2 mAh g−1 at a high current density of 5000 mA g−1, quickly back towards 2838.6 mAh g−1 at 200 mA g−1. The inclusion of B and P elements is linked to the electrochemical characteristics. In the co-doped carbon layers, the synergistic impact of doping B and P accelerates the diffusion kinetics of lithium ions, boosts diffusion rate of Li+, offers low electrochemical impedance (45.75 Ω). This brings more defects to provide transport carriers and induces a substantial amount of electrochemically active sites, which fosters the storage of Li+, thus making silicon material electrochemically more active and potential. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) has extensively utilized in electric vehicles and portable electronics due to their high energy density and prolonged lifespan. However, the current commercial LIBs are plagued by relatively low energy density. High-entropy materials with multiple components have emerged as an efficient strategic approach for developing novel materials that effectively improve the overall performance of LIBs. This article provides a comprehensive review the recent advancements in rational design of innovative high-entropy materials for LIBs, as well as the exceptional lithium ion storage mechanism for high-entropy electrodes and considerable ionic conductivity for high-entropy electrolytes. This review also analyses the prominent effects of individual components on the high-entropy materials' exceptional capacity, considerable structural stability, rapid lithium ion diffusion, and excellent ionic conductivity. Furthermore, this review presents the synthesis methods and their influence on the morphology and properties of high-entropy materials. Ultimately, the remaining challenges and future research directions are outlined, aimed at developing more effective high-entropy materials and improving the overall electrochemical performance of LIBs. [ABSTRACT FROM AUTHOR]

In the context of 'energy shortage', developing a novel energy-based power system is essential for advancing the current power system towards low-carbon solutions. As the usage duration of lithium-ion batteries for energy storage increases, the nonlinear changes in their aging process pose challenges to accurately assess their performance. This paper focuses on the study LiFeO4(LFP), used for energy storage, and explores their performance degradation mechanisms. Furthermore, it introduces common battery models and data structures and algorithms, which used for predicting the correlation between electrode materials and physical parameters, applying to state of health assessment and thermal warning. This paper also discusses the establishment of digital management system. Compared to conventional battery networks, dynamically reconfigurable battery networks can realize real-time monitoring of lithium-ion batteries, and reduce the probability of fault occurrence to an acceptably low level. [ABSTRACT FROM AUTHOR]

The discovery of novel electrode materials based on two-dimensional (2D) structures is critical for alkali metal-ion batteries. Herein, we performed first-principles computations to investigate functionalized MXenes, Mo2BT2 (T = O, S), which are also regarded as B-based MXenes, or named as MBenes, as potential anode materials for Li-ion batteries and beyond. The pristine and T-terminated Mo2BT2 (T = O, S) monolayers reveal metallic character with higher electronic conductivity and are thermodynamically stable with an intrinsic dipole moment. Both Mo2BO2 and Mo2BS2 monolayers exhibit high theoretical Li/Na/K storage capacity and low ion diffusion barriers. These findings suggest that functionalized Mo2BT2 (T = O, S) monolayers are promising for designing viable anode materials for high-performance alkali-ion batteries. [ABSTRACT FROM AUTHOR]

Si nanoparticles with independently controlled size and oxygen content have been produced by plasma spraying physical vapor deposition followed by the retarded oxidation. These nanoparticles are used as the negative electrode of all-solid-state batteries with sulfide solid electrolyte, and the influence of size and oxygen content on battery performance has been analyzed. The cells containing Si nanoparticles smaller than 150 nm with the oxygen content x in SiO x smaller than 0.1 have attained relatively high capacity and a good stable cyclability simultaneously after 50 cycles. This could be due to the formation of unique and uniform synaptic-like Si network with small Si nanoparticles within the electrode maintaining a firm contact with the Cu foil, which contrasts to large lateral crack formation for the cell with large Si particles. [ABSTRACT FROM AUTHOR]

The role of batteries in electrification of vehicles is eminent; thus, a dynamic model that represents the physics-based phenomena of the battery system at a minimum computational cost is essential in the model-based design of electrified vehicle control systems. Furthermore, robustness of the reduced-order battery model when maintaining the dominant physics-based phenomena governing the dynamic behavior of the battery system is crucial. Characterization of the power signal applied to the lithium-ion battery in the energy management controller of a plug-in hybrid electric vehicle shows that there is a dominant frequency range in the input signal to the battery. This key feature can be considered as a basis to construct a reduced-order model in which the training input is different from the original power signal. The original idea in this paper is to generate the training input by applying a low-pass filter to the white-noise random signal to maintain the same dominant frequency range observed in the original power signal. Response of the reduced-order model, constructed using the proper orthogonal decomposition, compared to the high-fidelity battery model shows promising results; a maximum relative error of 1% was obtained for the battery state of charge while simulation time was reduced by 42.9%. [ABSTRACT FROM AUTHOR]

In this work, a new MoO3@Mo2CT x nanocomposite was prepared from two–dimensional (2D) Mo2CT x MXene by in situ oxidization in air, which exhibited wonderful lithium-storage performance as anodes of lithium–ion batteries (LIBs). The precursor Mo2CT x was synthesized from Mo2Ga2C by selective etching of NH4F at 180 °C for 24 h. Thereafter, the Mo2CT x was oxidized in air at 450 °C for 30 min to obtain MoO3@Mo2CT x nanocomposite. In the composite, in situ generated MoO3 nanocrystals pillar the layer structure of Mo2CT x MXene, which increases the interlayer space of Mo2CT x for Li storage and enhances the structure stability of the composite. Mo2CT x 2D sheets provide a conductive substrate for MoO3 nanocrystals to enhance the Li+ accessibility. As anodes of LIBs, the final discharge specific capacity of the MoO3@Mo2CT x composite was 511.1 mAh g–1 at a current density of 500 mA g–1 after 100 cycles, which is about 36.7 times that of pure Mo2CT x MXene (13.9 mAh g–1) and 3.2 times that of pure MoO3 (159.9 mAh g–1). In the composites, both Mo2CT x and MoO3 provide high lithium storage capacity and can enhance the performance of each other. Moreover, this composite can be made by a facile method of in situ oxidation. Therefore, the MoO3@Mo2CT x MXene nanocomposite is a promising anode of LIB with high performance. [ABSTRACT FROM AUTHOR]

Mesoporous materials have received growing interest, particularly as electrode materials for lithium-ion battery applications since they provide short transportation length for Li ion and electrons, and favour electrolyte wettability. Such unique features are highly beneficial for improving the electrochemical performance of olivine LiFePO4 as this material has intrinsically low electronic and ionic conductivities, which otherwise would affect the storage performance. In addition, this sluggish kinetic brings about huge polarisation specifically at high current rates, resulting in poor energy efficiency. In order to overcome such kinetic issues, we present here a facile soft template-solvothemal method to synthesise mesoporous LiFePO4. Such mesoporous LiFePO4 is made of well interconnected nanograins (20–30 nm) which exhibits excellent storage performance and long-term cycling stability. In particular, the material shows improved storage performance at high rates with significantly less polarisation and clear signature of voltage plateaus for both Li ion insertion-extraction processes. In comparison with the LiFePO4 synthesized by the soft template method, the mesoporous LiFePO4 demonstrates excellent storage performance. This is attributed to the 2-D diffusion of both Li ions and electrons along b - and c -axes consistent with the 2-D Li ions transport reported previously for LiFePO4 single crystal. [ABSTRACT FROM AUTHOR]

This Focus aims at showcasing the significance of manipulating atomic and molecular layers for various applications. To this end, this Focus collects 15 original research papers featuring the applications of atomic layer deposition, chemical vapor deposition, wet chemistry, and some other methods for manipulations of atomic and molecular layers in lithium-ion batteries, supercapacitors, catalysis, field-effect transistors, optoelectronics, and others. [ABSTRACT FROM AUTHOR]

The article focuses on the performance and degradation of lithium-ion batteries (LIBs), emphasizing the importance of predicting their state of health (SOH) for ensuring safety and efficiency, including the development of physics-based model to understand the two-stage capacity degradation in LIBs.

The Si/FeSi2@C composite material offers several advantages due to its unique design. It effectively combines the high capacity and safety features of the Si negative electrode with FeSi2's stabilizing properties. By incorporating a homogeneous carbon layer, the composite material enhances electrical conductivity and provides structural support, thereby mitigating the detrimental effects of significant volume expansion resulting from repeated insertion and extraction of lithium ions. Furthermore, the composite material contributes to stabilizing the solid-electrolyte interphase (SEI) film, which is a critical factor in battery performance. The improved SEI film stability, combined with the overall enhancement in electronic conductivity, significantly enhances the performance of the negative electrode. Test results demonstrate that the composite, consisting of pyrolyzed polyacrylonitrile and Si/FeSi2 nanoparticles, exhibits excellent electrochemical properties. During the first charging cycle, the composite material achieves a specific capacity of 1280 mAh g−1. Impressively, after 200 cycles, the specific capacity of the composite doubles compared to that of the raw material, indicating a remarkable improvement in cycling stability. These findings highlight the positive impact of rational material design on the performance of the Si/FeSi2@C composites. [ABSTRACT FROM AUTHOR]

This work reports an in situ, one-step hydrothermal preparation procedure of a binder-free electrode growth of Ni6Se5 on nickel foam (Ni6Se5/NF) with a rod-like structure. Ni6Se5 is an enveloped transition metal chalcogenides of formula M(n +1)X n (where 2 ≤ n ≤ 8, M is a transition metal and X is chalcogen) of the nickel selenide family. The Ni6Se5/NF electrode described here demonstrates an exceptional lifetime of 81% capacitance retention over 20000 cycles and a high specific capacitance of 473.5 Fg−1 at a current density of 4 Ag−1. The Ni6Se5/NF/activated carbon asymmetric supercapacitor (SC) exhibits a remarkable 97.3 Whkg−1 energy density and a 2325 Wkg−1 power density. Ni6Se5 served as an active electrode material in SC applications and offered exceptional power density and long cycle life. Ni6Se5/NF, used as an anode for Li-ion batteries, has a lithium storage capacity of 939.7 mAhg−1 at 100 mAg−1 current density. Ni6Se5's (active electrode material) excellent energy storage capability, which was previously unreported, is particularly beneficial for electrochemical energy storage device applications. [ABSTRACT FROM AUTHOR]

In recent years, ternary nickel-rich layered oxides have gradually replaced traditional binary cathode materials in the lithium-ion battery market due to their advantages of high energy density and environmental protection. However, their structural instability of cathode materials has seriously affected the cycle performance of the battery. In order to optimize the internal structure of LiNi0.5Co0.2Mn0.3O2 (NCM523), the modified LiNi0.5Co0.2Mn0.3O2 was prepared by in situ doping Na and Cl wet grinding solid phase method. After 80 cycles at 1 C, the capacity retention rate was 80.91%, which was higher than that of LiNi0.5Co0.2Mn0.3O2 by 70.00%. Scanning electron microscopy showed that the surface corrosion of LiNi0.5Co0.2Mn0.3O2 was effectively alleviated by Na and Cl co-doping. In addition, the band structure, state density and volume changes were obtained by simulation. The results show that the impedance, capacity and capacity retention data are very compatible with the simulation results. Therefore, Na and Cl doping can effectively optimize the internal structure of LiNi0.5Co0.2Mn0.3O2 and improve its electrochemical performance. The combination of simulation and experiment provides a new approach for the modification of ternary cathode materials. [ABSTRACT FROM AUTHOR]

The structural transformations, oxygen releasing and side reactions with electrolytes on the surface are considered as the main causes of the performance degradation of Li-rich layered oxides (LROs) cathodes in Li-ion batteries. Thus, stabilizing the surfaces of LROs is the key to realize their practical application in high energy density Li-ion batteries. Surface coating is regarded as one of the most effective strategies for high voltage cathodes. The ideal coating materials should prevent cathodes from electrolyte corrosion and possess both electronic and Li-ionic conductivities simultaneously. However, commonly reported coating materials are unable to balance these functions well. Herein, a new type of coating material, La2CuO4 was introduced to mitigate the surface issues of LROs for the first time, due to its superb electronic conductivity (26–35 mS⋅cm−1) and lithium-ionic diffusion coefficient (10−12–10−13 cm2⋅s−1). After coating with the La2CuO4, the capacity retention of Li1.2Ni0.54Co0.13Mn0.13O2 cathode was increased to 85.9% (compared to 79.3% of uncoated cathode) after 150 cycles in the voltage range of 2.0–4.8 V. In addition, only negligible degradations on the deliverable capacity and rate capability were observed. [ABSTRACT FROM AUTHOR]

Enabling lithium-ion batteries (LIBs) to operate in a wider temperature range, e.g., as low or high as possible or capable of both, is an urgent need and shared goal. Here we report, for the first time, a low-temperature electrolyte consisting of traditional ethylene carbonate, methyl acetate, butyronitrile solvents, and 1 M LiPF6 salt, attributed to its very low freezing point (T f = −126.3 °C) and high ion conductivity at extremely low temperatures (0.21 mS/cm at −100 °C), successfully extends the service temperature of a practical 9.6 Ah LIB down to −100 °C (49.6% capacity retention compared to that at room temperature), which is the lowest temperature reported for practical cells so far as we know, and is lower than the lowest natural temperature (−89.2 °C) recorded on earth. Meanwhile, the high-temperature performance of lithium-ion batteries is not affected. The capacity retention is 88.2% and 83.4% after 800 cycles at 25 °C and 45 °C, respectively. The progress also makes LIB a proper power supplier for space vehicles in astronautic explorations. [ABSTRACT FROM AUTHOR]

The growth of artificial synthesis two-dimensional (2D) materials usually demands for suitable substrate due to their rare bulk allotropies. Borophene, as a typical artificial synthetic material, has been proved its substrate-growth on metal or nonmetals and its high theoretical specific capacity (1720 mAh g−1) for next-genatration electrode material, but structural instability and transfer difficulties have hindered the development of its applications. Here, a structurally stable and freestanding AA-stacked- α ′-4H-borophene sheets have been synthesized by in situ lithium eutectic salt-assisted synthetic method to realize the application of borophene in lithium-ion battery. The atomic structure of AA- α ′-4H-borophene with interlayer VdWs was established by comparing the experimental observation with DFT optimal calculation. Different stacking configurations (AA- and AB-) of borophene was realized by a temperature-structure-photoluminescence intensity relationship, and the AA-stacked borophene exhibits higher specific capacity than AB structure. Based on electrochemical performance, the AA-borophene exhibits excellent rate capability and cycling performance due to its non-collapsible stacking configurations, which dominates great initial coulombic efficiency of 87.3% at 200 mA g−1 superior to that of black phosphorus-based and borophene/graphene. Meanwhile, it still maintains the coulombic efficiency of 99.13% after 1000 cycles. It also shows a reversible capacity of 181 mAh g−1 at 10 mA g−1 between the voltage window of 0.01 and 2 V, which improves the reported capacity (43 mAh g−1) of bulk boron anode by over 430%. This work brings fantastic new view of fabricating stable, stacking and freestanding borophene and provides a significative idea on applications of borophene in energy storage domain. [ABSTRACT FROM AUTHOR]

Novel composite materials comprising of silicon nanoparticles (SiNPs) encapsulated with thin layers of silicon nitride and reduced graphene oxide shells (Si@Si3N4@rGO) are prepared using a simple and scalable method. The composite exhibits significantly improved cycling stability and rate capability compared to bare SiNPs. The presence of inactive α and β phases of Si3N4 increases the mechanical endurance of SiNPs. Amorphous SiN x, which is possibly present with Si3N4, also contributes to high capacity and Li-ion migration. The rGO sheath enhances the electronic conduction and improves the rate capability. 15-Si@Si3N4@rGO, which is prepared by sintering SiNPs for 15 min at 1300 °C, spontaneous-coating GO on Si@Si3N4, and reducing GO to rGO, delivers the highest specific capacity of 1396 mAh g−1 after 100 cycles at a current density of 0.5 A g−1. The improved electrochemical performance of 15-Si@Si3N4@rGO is attributed to the unique combination of positive effects by Si3N4 and rGO shells, in which Si3N4 mitigates the issue of large volume changes of Si during charge/discharge, and rGO provides efficient electron conduction pathways. Si@Si3N4@rGO composites are likely to have great potential for a high-performance anode in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Group IV elements and their oxides, such as Si, Ge, Sn and SiO have much higher theoretical capacity than commercial graphite anode. However, these materials undergo large volume change during cycling, resulting in severe structural degradation and capacity fading. Al2O3 coating is considered an approach to improve the mechanical stability of high-capacity anode materials. To understand the effect of Al2O3 coating directly, we monitored the morphology change of coated/uncoated Sn particles during cycling using operando focused ion beam–scanning electron microscopy. The results indicate that the Al2O3 coating provides local protection and reduces crack formation at the early stage of volume expansion. The 3 nm Al2O3 coating layer provides better protection than the 10 and 30 nm coating layer. Nevertheless, the Al2O3 coating is unable to prevent the pulverization at the later stage of cycling because of large volume expansion. [ABSTRACT FROM AUTHOR]

As a lithium-ion battery cathode material with high theoretical capacity, the application of V2O5 is limited by its unstable structure and low intrinsic conductivity. In this paper, we report a Fe doped V2O5 nanowire with a layered structure of 200–300 nm diameter prepared by electrostatic spinning technique. The 3Fe-V2O5 electrode exhibited a superb capacity of 436.9 mAh g−1 in the first cycle when tested in the voltage range of 2.0–4.0 V at current density of 100 mA g–1, far exceeding its theoretical capacity (294 mAh g−1), and the high capacity of 312 mAh g−1 was still maintained after 50 cycles. The superb performance is mainly attributed to its unique layered nanowire structure and the enhanced electrical conductivity as well as optimized structure brought by Fe-doping. This work made the homogeneous doping and nanosizing of the material easily achieved through electrostatic spinning technology, leading to an increase in the initial capacity of the V2O5 cathode material and the cycling stability compared to the pure V2O5, which is an extremely meaningful exploration. [ABSTRACT FROM AUTHOR]

Group IV elements and their oxides, such as Si, Ge, Sn and SiO have much higher theoretical capacity than commercial graphite anode. However, these materials undergo large volume change during cycling, resulting in severe structural degradation and capacity fading. Al2O3 coating is considered an approach to improve the mechanical stability of high-capacity anode materials. To understand the effect of Al2O3 coating directly, we monitored the morphology change of coated/uncoated Sn particles during cycling using operando focused ion beam–scanning electron microscopy. The results indicate that the Al2O3 coating provides local protection and reduces crack formation at the early stage of volume expansion. The 3 nm Al2O3 coating layer provides better protection than the 10 and 30 nm coating layer. Nevertheless, the Al2O3 coating is unable to prevent the pulverization at the later stage of cycling because of large volume expansion. [ABSTRACT FROM AUTHOR]

To reduce the cost of electrode fabrication and provide a pathway for facile recycling of battery active materials, electrochemical deposition and lithiation of manganese (Mn) oxide cathodes have been proposed in the literature. However, without sufficient physicochemical characterization, many works have postulated that the active lithium manganese oxide (LMO) phase is created from crystalline MnO2 or Mn3O4. This work shows that neither of those phases nor other well-known stoichiometric crystalline phases (i.e., MnO and Mn2O3), lead to the formation of LMO. This work confirms the specific active surface features obtained by the potentiostatic deposition of Mn oxide, their chemical lithiation, and heat treatment. The resulting LMO electrodes were incorporated into coin cells, cycled—achieving a capacity over 250 mAh g−1 —and post-characterized. [ABSTRACT FROM AUTHOR]

Electric vehicle batteries must possess fast rechargeability. However, fast charging of lithium-ion batteries remains a great challenge. This paper develops a feature-driven closed-loop optimization (CLO) methodology to efficiently design health-conscious fast-charging strategies for batteries. To avoid building an early outcome predictor, the feature highly related to battery end-of-life is used as the optimization objective instead of using the predicted lifetime. This feature is extracted from the battery’s early cycles and the experimental cost is thus reduced. By developing closed-loop multi-channel experiments with Bayesian optimization (BO), the optimal charging protocols with long cycle lives are located quickly and efficiently among 224 four-step, 10 min fast-charging protocols. Experimental results show that BO performs well with different acquisition functions, and a minimum of 12 paralleled channels for each round of experiments are recommended to obtain stable optimization results. Compared with the benchmark, the developed method recommends similar fast-charging protocols with long cycle lives based on much less experimental cost. [ABSTRACT FROM AUTHOR]

In this work, two strategies have been attempted to achieve decent fast-charging performances of Li-ion batteries. The first is to combine lithium bis(fluorosulfonyl)imide (LiFSI) and dimethoxyethane (DME) into an electrolyte for high ionic conductivity of the bulk electrolyte and the electrolyte-electrode interphases, and the second is to limit charging capacity within 80% state-of-charge (SOC) for stable capacity retention by lowering charging rate without increasing total charging time in the standard constant current-constant voltage (CC-CV) charging protocol. It is found that using 5 wt% fluoroethylene carbonate (FEC) as an additive enables the hybridization of 20 wt% DME into the electrolyte without adverse effects on the initial formation cycles and ongoing cycling in terms of coulombic efficiency and reversible capacity, and adding 2 wt% LiPF6 is beneficial to reducing charge-transfer resistance and stabilizing capacity retention. As a result, decent fast-charging performances are obtained from the 200 mAh graphite/LiNi0.80Co0.15Al0.05O2 pouch cells by using a 1.2 m (molality) LiFSI 3:5:2 ethylene carbonate (EC)/ethylmethyl carbonate (EMC)/DME + 5% FEC + 2% LiPF6 electrolyte (all by wt) and a modified CC-CV charging protocol consisting of CC charging at 4 C for a total of 12 min, which is the charging time equivalent to a 5 C charging protocol. [ABSTRACT FROM AUTHOR]

Zinc-air batteries (ZABs) are devices of great interest as a replacement option for subsequent technologies to lithium-ion batteries. Still, the need for suitable electrolyte materials limits their application in commercial devices. In this study, a green hydrogel composed of chitosan and carboxymethylcellulose was synthesized with the use of citric acid as a chemical crosslinker, physical freezing-thawing, and freezing-drying strategies. Physicochemical, thermal, and electrochemical characterizations were performed to study the effects of the proposed synthesis’ on the performance of the hydrogels for the desired application. The obtained hydrogels showed a porous morphology that was doped with a 12M KOH solution. Adequate complexation of K+ cations and the polymer chains was observed. The resulting membranes showed an enhanced ionic conductivity of 0.39 S cm‒1, attributed to the pores and channels generated by the crosslinking strategies, contributing to the pathways for ions to move easily. In addition, the temperature dependence of the conduction mechanism was confirmed in the temperature range of 0 °C to 70 °C. The electrolytes were employed in ZABs prototypes, achieving a maximum power density of 117 mW cm‒2 and a specific capacitance of 1899 mAh g‒1 . The presented results show the promising properties of these hydrogels as electrolytes for green storage devices. [ABSTRACT FROM AUTHOR]

High-energy-density rechargeable lithium batteries are being pursued by researchers because of their revolutionary potential nature. Current advanced practical lithium-ion batteries have an energy density of around 300 W⋅h⋅kg−1. Continuing to increase the energy density of batteries to a higher level could lead to a major explosion development in some fields, such as electric aviation. Here, we have manufactured practical pouch-type rechargeable lithium batteries with both a gravimetric energy density of 711.3 W⋅h⋅kg−1 and a volumetric energy density of 1653.65 W⋅h⋅L−1. This is achieved through the use of high-performance battery materials including high-capacity lithium-rich manganese-based cathode and thin lithium metal anode with high specific energy, combined with extremely advanced process technologies such as high-loading electrode preparation and lean electrolyte injection. In this battery material system, the structural stability of cathode material in a widened charge/discharge voltage range and the deposition/dissolution behavior of interfacial modified thin lithium electrode are studied. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g-1 at 500 mA g-1 current density and 580 mAh g-1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g-1 capacity at 150 mAh g-1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D electrode designing approach toward high-performance Li-ion and Na-ion storage capability. [ABSTRACT FROM AUTHOR]

Modern batteries are highly complex devices. The cells contain many components—which in turn all have many variations, both in terms of chemistry and physical properties. A few examples: the active materials making the electrodes are coated on current collectors using solvents, binders and additives; the multicomponent electrolyte, contains salts, solvents, and additives; the electrolyte can also be a solid ceramic, polymer or a glass material; batteries also contain a separator, which can be made of glass fibres, polymeric, ceramic, composite, etc. Moving up in scale all these components are assembled in cells of different formats and geometries, coin cells and Swagelok cells for funamental testing and understanding, and pouch, prismatic and cylindrical cells for application. Given this complexity dictated by so many components and variations, there is no wonder that addressing the crucial issue of true sustainability is an extremely challenging task. How can we make sure that each component is sustainable? How can the performance can be delivered using more sustainable battery components? What actions do we need to take to address battery sustainability properly? How do we actually qualify and quantify the sustainability in the best way possible? And perhaps most importantly; how can we all work—academia and battery industry together—to enable the latter to manufacture more sustainable batteries for a truly cleaner future? This Roadmap assembles views from experts from academia, industry, research institutes, and other organisations on how we could and should achieve a more sustainable battery future. The palette has many colours: it discusses the very definition of a sustainable battery, the need for diversification beyond lithium-ion batteries (LIBs), the importance of sustainability assessments, the threat of scarcity of raw materials and the possible impact on future manufacturing of LIBs, the possibility of more sustainable cells by electrode and electrolyte chemistries as well as manufacturing, the important role of new battery chemistries, the crucial role of AI and automation in the discovery of the truly sustainable batteries of the future and the importance of developimg a circular battery economy.

As the most successful new energy storage device developed in recent decades, lithium-ion batteries (LIBs) are ubiquitous in the modern society. However, current commercial LIBs comprising mainly intercalated cathode materials are limited by the theoretical energy density which cannot meet the high storing energy demanded by renewable applications. Compared to intercalation-type cathode materials, low-cost conversion-type cathode materials with a high theoretical specific capacity are expected to boost the overall energy of LIBs. Among the different conversion cathode materials, metal fluorides have become a popular research subject for their environmental friendliness, low toxicity, wide voltage range, and high theoretical specific capacity. In this review, we compare the energy storage performance of intercalation and conversion cathode materials based on thermodynamic calculation and summarize the main challenges. The common conversion-type cathode materials are described and their respective reaction mechanisms are discussed. In particular, the structural flaws and corresponding solutions and strategies are described. Finally, we discussed the prospective of metal fluorides and other conversion cathode materials to guide further research in this important field.

When we engage in discussions about lithium-ion batteries (LIBs), one of the most common questions asked by our colleagues, friends, and family is "Are lithium-ion batteries safe?" The answer to this important question is, for the individual, "Yes." Despite the ubiquity of LIBs in our daily lives, the failure rates of these batteries are sufficiently low such that the chances of a failure affecting an individual using a battery for its intended purpose are vanishingly small. However, there is no room for complacency, as over 25 years of field experience has shown that there are inherent safety risks associated with LIB technologies. These are commonly related to in-service abuse by consumers, LIBs manufactured with poor quality and/or poor manufacturing controls, and many other factors. [ABSTRACT FROM AUTHOR]

Li-metal anodes exhibit the potential to increase the efficiencies of Li-ion battery systems. However, the commercialization of Li metal is hindered by several inherent challenges, such as the formation of inhomogeneous Li dendrites and considerable volume expansion during deposition and dissolution. Fabrication of 3D porous structures is a promising technique that resolves these problems, however, no attempts to replace graphite anodes with porous Li-Cu anodes in Li-ion secondary battery systems are reported. Moreover, the charging/discharging behaviors of porous Li-Cu anodes are not yet completely understood. In this study, the changes in a porous Li-Cu anode in a symmetric cell during lithiation and delithiation are investigated. The porous Li-Cu anode suppresses dendrite growth and volume changes via the filling and evacuation of the pores around the Li particles within and on the surface of the anode, and thus, the higher porosity results in a larger capacity. The Li-Cu anode displays a stable cyclability at 1 mA cm-2 with a capacity of 1 mA h cm-2 over 700 h. The porous Li-Cu anode exhibits promise in replacing graphite in Li-ion secondary battery systems. [ABSTRACT FROM AUTHOR]

Accurate lithium-ion battery charge state estimation is crucial for battery management systems. Modeling of dual polarization--electrical equivalent circuit based on ternary lithium batteries as a research object, a variable forgetting factor recursive least square method is proposed for parameter identification given the insufficient tracking ability of the traditional recursive least squares method for abrupt and time-varying signals in a non- stationary environment. A backward smoothing square root cubature Kalman filtering algorithm is applied to enhance the accuracy and convergence speed of SOC estimation. The algorithm uses the square root update to ensure the numerical stability of the filtering and uses the idea of backward smoothing-forward filtering to improve the filtering accuracy on the basis of the first forward filtering. Finally, variable forgetting factor recursive least square is combined with backward smoothing square root cubature Kalman filtering to achieve the joint estimation of model parameters and state of charge, and the feasibility of the battery state of charge estimation is verified in different working conditions. The simulation results show that the variable forgetting factor recursive least square-backward smoothing square root cubature Kalman filter algorithm improves the study's filtering accuracy and convergence speed of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Emerging lithium-ion battery systems require high-fidelity electrochemical models for advanced control, diagnostics, and design. Accordingly, battery parameter estimation is an active research domain where novel algorithms are being developed to calibrate complex models from input-output data. Amidst these efforts, little focus has been placed on the fundamental mechanisms governing estimation accuracy, spurring the question, why is an estimate accurate or inaccurate? In response, we derive a generalized estimation error equation under the commonly adopted least-squares objective function, which reveals that the error can be represented as a combination of system uncertainties (i.e., in model, measurement, and parameter) and uncertaintypropagating sensitivity structures in the data. We then relate the error equation to conventional error analysis criteria, such as the Fisher information matrix, Cramér-Rao bound, and parameter sensitivity, to assess the benefits and limitations of each. The error equation is validated through several uni- and bivariate estimations of lithium-ion battery electrochemical parameters using experimental data. These results are also analyzed with the error equation to study the error compositions and parameter identifiability under different data. Finally, we show that adding target parameters to the estimation without increasing the amount of data intrinsically reduces the robustness of the results to system uncertainties. [ABSTRACT FROM AUTHOR]

Broadening the portfolio of cathode active materials for Li-ion battery applications is now more important than ever. Recent focus on enabling diversity and security in supply chains, as well as concerns over sustainability of a massively growing energy storage market, have put emphasis on enabling more Earth-abundant cathode materials as an attractive strategy. With respect to relatively near-term options, manganese-based cathodes are particularly interesting. Herein we discuss some of the challenges associated with advancing the development of manganese-based oxides and, in particular, those that take advantage of complex local structures and/or over-lithiated compositions. Discussion centers on the representative, lithium- and manganese-rich class of cathodes and considerations to future development are given that range from the atomic-scale to the electrode level. [ABSTRACT FROM AUTHOR]

Carbon materials derived from metal-organic frameworks have attracted increasing attention as anodes for energy storage. In this study, Fe, Ni-doped ZIF-8 is carbonized at high temperature to obtain bimetallic Fe and Ni modified tension -relaxed carbon (FeNi@trC). Fe and Ni have opposite structural modification effects when the metal ions are doped into the ZIF-8 dodecahedron. The obtained carbon material maintains the regular dodecahedron morphology, which means the relaxation of tension and strong thermal stability during annealing. Moreover, the presence of nickel enhances the carbonization degree and electrochemical stability of FeNi@trC, while the calcination of the tensive ZIF-8 precursor offers more defect sites. The discharge capacities of FeNi@trC materials are stable at 182.9 mAh·g−1 and 567.9 mAh·g−1 for sodium-ion batterie (SIB) and lithium-ion batterie (LIB) at 0.05 A·g−1. Compared with the current density of 0.05 A·g−1, the discharge capacity of SIB and LIB attenuates by 29.4% and 55.9% at 1 A·g−1, respectively, and the FeNi@trC shows good performance stability in the following cycles. [ABSTRACT FROM AUTHOR]

To improve power and cycling performance of lithium-ion batteries, dual-layer or porosity-gradient electrodes have been proposed. By engineering a higher porosity close to the separator, the intention is to improve ion transport where it is most impactful. In this research, MacMullin numbers of two dual-layer anode samples are tested using an impedance measurement technique developed previously. To characterize the microstructure of each layer independently, we developed an improved transmission-line model that accounts for each layer's properties.Virtual experiments using COMSOL Multiphysics to simulate impedance measurements are used to examine and improve the accuracy of the numerical inversion procedure. The results for the two dual-layer anodes studied show that MacMullin numbers follow expected trends, though the anodes are quite different from each other. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have emerged as a technological game-changer. Due to the rising price of lithium and the environmental concerns LIBs pose, their use is no longer viable. Sodium (Na) may be the best contender among the alternatives for replacing lithium. Conventional graphite has a limited capacity for Na storage. Hence, α -graphyne, an allotrope of carbon, was studied here as a potential anode material for Na-ion batteries (NIBs), employing density functional theory. In-plane Na atom adsorption results in a semi-metallic to metallic transition of α -graphyne. Electronic transport calculations show an increase in current after Na adsorption in graphyne. The successive adsorption of Na atoms on the surface of graphyne leads to a theoretical capacity of 1395.89 mA h gâˆ'1, which is much greater than graphite. The average open circuit voltage is 0.81 V, which is an ideal operating voltage for NIBs. Intra- and inter-hexagon Na diffusions have very low energy barriers of 0.18 eV and 0.96 eV, respectively, which ensure smooth operation during charge/discharge cycles. According to this study, the α -graphyne monolayer thus has the potential to be employed as an anode in NIBs. [ABSTRACT FROM AUTHOR]

The solid electrolyte interphase (SEI) plays an integral role in regulating the stability of lithium-ion batteries, particularly those employing next-generation anode materials like lithium (Li)-metal or silicon (Si). Herein, a locally concentrated additive framework is designed to incorporate a LiNO3 sacrificial additive into conventional carbonate-containing electrolytes to heighten electrochemical stability in such systems. Though LiNO3 is effectively insoluble in carbonate solvents, it is introduced in moderate amounts to the electrolyte in the form of a highly concentrated diglyme complex, which is then dispersed and diluted throughout the bulk carbonate electrolyte in a homogenous, liquid, phase-stable solution. The addition of this additive complex considerably enhances the electrochemical stability of 4 V systems containing Li-metal or Si anodes over the course of cycling as well as during potentiostatic holds. It is shown that the sacrificial reduction of LiNO3 leads to the formation of favorable nitrogen-containing species on the surface of Si, like what is known to occur with Li-metal. However, the initial deposition of these products is found to transform the SEI towards having greater inorganic character overall, with significantly more embedded LiF throughout. These insights expand our understanding of electrolyte and SEI design for electrochemically resilient next-generation anode systems. [ABSTRACT FROM AUTHOR]

Degradation phenomena in Li-ion batteries are highly complex, coupled, and sensitive to use history and operating conditions. In this study, we show how tracking model parameters in continuum-level physics-based models, expedited by machine learning, can be useful in testing hypotheses for degradation mechanisms. An exemplary analysis using this approach is presented for a set of lithium trivanadate (LixV3O8) cathodes cycled over a range of current rates. A simple cell revival process is combined with the parameter estimates over the course of cycling to extract valuable insights into cathode evolution and eliminate hypothesized degradation mechanisms for these cathodes. The presented approach is expected to be broadly applicable for degradation analysis of other electrodes. [ABSTRACT FROM AUTHOR]

Increasing electrode thickness can increase the energy density of lithium-ion batteries. However, increasing electrode thickness increases transport limitations and the risk of lithium plating. This work analyzes prospective improvements to the conventional lithium-ion cell that may facilitate high energy density and fast charging capabilities. A 2D lithium-ion battery model is applied to understand the impact of thick electrode at different C-rates in a single cell stack. Five different cell geometries were analyzed for this work: one conventional cell and four test cases in which the conventional electrode geometries were modified by adding electrolyte channels to increase the rate transfer capability of lithium ions at high C-rates and reduce the risk of lithium plating. All five configurations were simulated in discharge at C/10, C/2, and 1 C followed by simulated charging at 1 C, 3 C, and 5 C with no rest period prior to charge. The addition of electrolyte channels in the anode only results in improved performance with respect to reduced plating risk. Dimensionless parameter analysis was performed to compare the battery performance with different electrode modifications at different C-rates. Scaling behavior based on these parameters clarifies the benefits and limitations of the varied electrode modification approaches. [ABSTRACT FROM AUTHOR]