Fast Charging Of Lithium-ion Batteries Research Articles

An advanced CoNb2O6 anode material with in-situ interstitial doping for high-rate lithium-ion batteries

Niobium-based bimetallic oxide, as a potential anode material for fast-charging lithium-ion batteries, has attracted much attention owing to its unique lithium intercalation channel. However, the poor conductivity and structural instability of such material severely limit its further application. In this paper, CoNb2O6 was prepared by a molten-salt method and was in-situ doped with high-valence V5+ ion in different proportions. Different from conventional substitutional doping, a small amount of interstitial doping is more conducive to the entry of V5+ into the gap, which leads to lattice expansion. With the increase of doping amount, elemental Nb5+ was gradually replaced by V5+, which then hinders the Li+ intercalation/de-intercalation to a certain extent. Based on the DFT and electrochemical tests, the interstitial-doped CNO-V0.005 nanoparticles has not only faster Li+ diffusion kinetics and lower energy barrier, but also delivers high discharge capacity with long cycling stability at high current density of 2000 mA g−1 (≈ 8C). After assembling the full cell with CNO-V0.005 and commercial LiFePO4 cathode material, the reversible capacity of 150.6 mAh g−1 could be achieved after 200 cycles at the current density of 1000 mA g−1, demonstrating its application potential in fast- charging lithium-ion batteries.

Toward fast-charging lithium-ion batteries: Quantitatively tracking lithium plating on graphite

Toward fast-charging lithium-ion batteries: Quantitatively tracking lithium plating on graphite

Complex host structures and phase transitions in fast-charging lithium-ion battery anodes from diffraction and complementary techniques

Complex host structures and phase transitions in fast-charging lithium-ion battery anodes from diffraction and complementary techniques

Amorphous Vanadium Oxide Nanosheets with Alterable Polyhedron Configuration for Fast-Charging Lithium-Ion Batteries.

Transition metal oxides with high theoretical capacities are promising anode materials for lithium-ion batteries (LIBs). However, the sluggish reaction kinetics remain a bottleneck for fast-charging applications due to its slow Li+ migration rate. Herein, a strategy is reported of significantly reducing the Li+ diffusion barrier of amorphous vanadium oxide by constructing a specific ratio of the VO local polyhedron configuration in amorphous nanosheets. The optimized amorphous vanadium oxide nanosheets with a ratio ≈1:4 for octahedron sites (Oh ) to pyramidal sites (C4v ) revealed by Raman spectroscopy and X-ray absorption spectroscopy (XAS) demonstrate the highest rate capability (356.7mAhg-1 at 10.0Ag-1 ) and long-term cycling life (455.6mAhg-1 at 2.0Ag-1 over 1200 cycles). Density functional theory (DFT)calculations further verify that the local structure (Oh :C4v = 1:4) intrinsically changes the degree of orbital hybridization between V and O atoms and contributes to a higher intensity of electron occupied states near the Fermi level, thus resulting in a low Li+ diffusion barrier for favorable Li+ transport kinetics. Moreover, the amorphous vanadium oxide nanosheets possess a reversible VO vibration mode and volume expansion rate close to 0.3%, as determined through in situ Raman and in situ transmission electron microscopy.

Amorphous Sn modified nitrogen-doped porous carbon nanosheets with rapid capacitive mechanism for high-capacity and fast-charging lithium-ion batteries

Amorphous Sn modified nitrogen-doped porous carbon nanosheets with rapid capacitive mechanism for high-capacity and fast-charging lithium-ion batteries

Insight into pulse-charging for lithium plating-free fast-charging lithium-ion batteries

In recent years, tremendous efforts have been devoted to searching for the fast-charging methodology of lithium-ion battery (LIB) with widespread practical application of the electric vehicles, since the uncontrolled Li plating on the graphite anode under the fast-charging condition can lead the accelerated capacity decay and cause the safety issues of LIB. Here, we present mechanistic insights into the pulse-current-based fast-charging to aid with suppressing Li plating on the graphite anode. Compared with a conventional fast-charging protocol of the constant current method, the full-cell assembled with graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode exhibits the improved fast-charging capability and cycle performance under the pulse-charging protocol. In particular, the graphite anode after prolonged 300 cycles shows a clean surface free of plated Li, which confirms that the pulse-charging protocol effectively inhibits Li plating on the anode even under fast-charging conditions. Furthermore, the physics-based numerical modeling results demonstrate that the pulse-current redistributes the accumulated Li+ species at the electrolyte/anode interface periodically, which mitigates the anode potential drop and prevents consequent Li plating.

Feature-Driven Closed-Loop Optimization for Battery Fast Charging Design with Machine Learning

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.

Recycling water hyacinth stem waste for cost-effective production of carbon/FeOx nanocomposite anodes for sustainable fast-charging lithium-ion batteries

Recycling water hyacinth stem waste for cost-effective production of carbon/FeOx nanocomposite anodes for sustainable fast-charging lithium-ion batteries

Three-Dimensional Flower-like MoS2 Nanosheets Grown on Graphite as High-Performance Anode Materials for Fast-Charging Lithium-Ion Batteries.

The demand for fast-charging lithium-ion batteries (LIBs) with long cycle life is growing rapidly due to the increasing use of electric vehicles (EVs) and energy storage systems (ESSs). Meeting this demand requires the development of advanced anode materials with improved rate capabilities and cycling stability. Graphite is a widely used anode material for LIBs due to its stable cycling performance and high reversibility. However, the sluggish kinetics and lithium plating on the graphite anode during high-rate charging conditions hinder the development of fast-charging LIBs. In this work, we report on a facile hydrothermal method to achieve three-dimensional (3D) flower-like MoS2 nanosheets grown on the surface of graphite as anode materials with high capacity and high power for LIBs. The composite of artificial graphite decorated with varying amounts of MoS2 nanosheets, denoted as MoS2@AG composites, deliver excellent rate performance and cycling stability. The 20-MoS2@AG composite exhibits high reversible cycle stability (~463 mAh g-1 at 200 mA g-1 after 100 cycles), excellent rate capability, and a stable cycle life at the high current density of 1200 mA g-1 over 300 cycles. We demonstrate that the MoS2-nanosheets-decorated graphite composites synthesized via a simple method have significant potential for the development of fast-charging LIBs with improved rate capabilities and interfacial kinetics.

A medium/low concentration localized electrolyte for safe and fast-charging lithium-ion batteries

Localized high concentrations electrolyte (LHCE) has garnered significant attention as an emerging electrolyte candidate for Li-metal batteries. LHCE is formed by diluting a high concentration electrolyte (usually close to saturation) with a non-solvating solvent that has a low donor number. We propose a modified concept of LHCE, called "localized electrolyte (LE)," optimized for Li-ion batteries with a graphite anode and Ni-rich cathode. In LE, the Li salt concentration is optimized to be only 1-2 M in solvating solvents, resulting in an overall concentration of 0.5–1 M, which reduces cost and supports fast ion transport. The non-flammable LE also has excellent wettability, which facilitates fasting charging. We also demonstrated that with the addition of 2 wt.% vinylene carbonate into 0.7 M LE, the Li-ion cell retains 80.3% of its initial capacity after 700 cycles of testing in about 4 months. Overall, LE represents a promising and cost-effective solution for improving the performance and safety of Li-ion batteries.

Sn, S co-doped LiCoO2 with low lithium ion diffusion energy barrier and high passivation surface for fast charging lithium ion batteries

High-voltage lithium cobalt oxide (LCO) has been widely used in 5G smart electronics. However, maintaining the stability of high-voltage LCO structures under fast charging and discharging conditions is still a challenge that hinders its application in fast-charging lithium-ion batteries. Here, we propose a new idea of fully supported lattice network and self-passivating surface to construct a fast-charging cathode and realize high performance fast-charging lithium-ion battery. A fully supported lattice network can be achieved by one-step solid-phase sintering of Sn and S co-doped LCO, reducing the energy barrier of Li+ transport and allowing rapid Li+ solid-state diffusion. The self-passivating surface is formed on the surface of LCO-Sn0.6 by de-solvation with solvent molecules, which significantly increases the adsorption energy of EC and LiPF6 on LCO-Sn0.6, and greatly reduces the absorption ability of EC and LiPF6 on LCO-Sn0.6 to form effective CEI membranes. The superior performance with high capacity (114 mAh g−1) under extremely fast charging conditions (20 C, 1 C = 274 mA g−1) is achieved on Sn and S co-doped LCO cathode, that is, it can reach more than 60% SOC after only 2 min of fast charging. In situ Raman spectroscopy and in situ XRD further confirm the reversible transformation of Sn and S co-doped LCO microstructure during charge and discharge processes. These results provide a platform for the design of novel fast-charging cathode materials with fully supported lattice network and self-passivating surface, while stabilizing lattice structure and significantly enhancing ionic solid-state diffusion dynamics.

Layered-Oxide Cathode Materials for Fast-Charging Lithium-Ion Batteries: A Review.

Layered oxides are considered prospective state-of-the-art cathode materials for fast-charging lithium-ion batteries (LIBs) owning to their economic effectiveness, high energy density, and environmentally friendly nature. Nonetheless, layered oxides experience thermal runaway, capacity decay, and voltage decay during fast charging. This article summarizes various modifications recently implemented in the fast charging of LIB cathode materials, including component improvement, morphology control, ion doping, surface coating, and composite structure. The development direction of layered-oxide cathodes is summarized based on research progress. Further, possible strategies and future development directions of layered-oxide cathodes to improve fast-charging performance are proposed.

Si-C nanocomposites supported on vertical graphene sheets grown on graphite for fast-charging lithium ion batteries

Silicon/carbon (Si/C) anodes have been successfully used in commercial lithium-ion batteries because of their high capacity and excellent safety. Nevertheless, their cycling stability and fast-charging capability are still unsatisfactory due to large volume expansion and slow charge transport capability under industrial electrode conditions. Here, we fabricate a Si/C anode via homogeneously depositing amorphous SiC nanolayers on graphite armored with N-doped porous flexible vertical graphene sheets (VGSs) (named as Si-C/VGSs/graphite). SiC nanolayers consist of homogeneously dispersed sub-nanometer Si particles in 3D carbon skeleton, which effectively alleviate the volume change of Si, and hugely accelerate electron and Li-ion transport. The N-doped VGSs possess porous structure, good flexibility, numerous exposed edges, and directional ion transport channels, which provide rational space for accommodating volume change of Si, buffer the stress caused by the volume change, increase the electrical contact points between Si-C/VGSs/graphite, and accelerate Li-ion transport, respectively. Consequently, Si-C/VGSs/graphite delivers superior rate capacity and long cycle life under industrial electrode conditions. When matched with the cathode of Li[Ni0.8Co0.1Mn0.1]O2, the full cell demonstrates a predominant fast-charging capability (180.8 Wh kg−1, charging for 8.2 min, 5C) accompanied by long cycle life.

2D Layered Materials for Fast-Charging Lithium-Ion Battery Anodes.

The development of electric vehicles has received worldwide attention in the background of reducing carbon emissions, wherein lithium-ion batteries (LIBs) become the primary energy supply systems. However, commercial graphite-based anodes in LIBs currently confront significant difficulty in enduring ultrahigh power input due to the slow Li+ transport rate and the low intercalation potential. This will, in turn, cause dramatic capacity decay and lithium plating. The 2D layered materials (2DLMs) recently emerge as new fast-charging anodes and hold huge promise for resolving the problems owing to the synergistic effect of a lower Li+ diffusion barrier, a proper Li+ intercalation potential, and a higher theoretical specific capacity with using them. In this review, the background and fundamentals of fast-charging for LIBs are first introduced. Then the research progress recently made for 2DLMs used for fast-charging anodes are elaborated and discussed. Some emerging research directions in this field with a short outlook on future studies are further discussed.

Polyethylene ceramic separators with semi-interpenetrating polymer network boosting fast-charging cycle capacity retention and safety for lithium-ion batteries

Fast-charging lithium-ion batteries (LIBs) have recently received significant attention. In current commercial LIBs, lithium precipitation frequently occurs under long-term cycling and fast-charging conditions, adversely affecting their cycle capacity retention and safety. The primary cause of lithium precipitation is electrolyte loss during long-term cycling. In this study, a thermoplastic polyurethane/polyurethane acrylate semi-interpenetrating polymer network ceramic separator with high electrolyte retention (200%) and interfacial adhesion (6.6 N) is prepared and without a decrease in the energy density. The LiNi0.8Mn0.1Co0.1O2/graphite batteries fabricated with this separator show excellent electrochemistry properties (300 cycles, 1.5 C, discharge capacity of 3677 mAh, capacity retention of 93%). Furthermore, this study presents a novel strategy to mitigate the issue of lithium precipitation in fast-charging LIBs. Therefore, this functional separator is a promising alternative for the conventional commercial polyvinylidene difluoride separators and provides a new avenue for developing the next generation of fast-charging devices.

Ultrahigh edge‑nitrogen-doped porous carbon anode materials for high-capacity and fast-charging lithium-ion batteries

Most reported nitrogen-doped carbon anode materials of lithium-ion batteries (LIBs) own finite capacities and inferior initial coulombic efficiency (ICE). One effective method to enhance capacities and capacities of the nitrogen-doped carbon anode materials is edge‑nitrogen doping. It still endures obstacles to realize a high edge‑nitrogen doping level owing to the difficulty to control of the nitrogen doping types. In this work, a series of edge‑nitrogen-doped porous carbon (ENPC) with different edge‑nitrogen doping levels are synthesized by annealing sucrose and g-C3N4 in a sealed graphite crucible. The edge‑nitrogen doping level from 8.88 at.% to 12.93 at.% for the ENPC-T can be regulated by changing the annealing temperature. Serving as LIBs anodes, the ENPC-800 exhibits an excellent capacity (1251.1 mAh g−1 at 0.1 A g−1), high ICE (82.9 %) and remarkable cycle life (650.5 mAh g−1 at 1 A g−1 after 1000 cycles with an exceptional capacity retention of 99.3 %). More significantly, by correlating the capacity and conductivity with the nitrogen doping configuration of the ENPC-T materials, the results highlight the effect of edge‑nitrogen on the capacity and conductivity. Meanwhile, the electrochemical characterizations of CV, GITT and EIS illustrate that a higher edge‑nitrogen doping level improves the capacity, electronic conductivity and fast-charging performance of ENPC-T. This new strategy can pave a new approach for the investigation and application of nitrogen-doped carbon anodes.

Monolayer MoS2 Fabricated by In Situ Construction of Interlayer Electrostatic Repulsion Enables Ultrafast Ion Transport in Lithium-Ion Batteries

HighlightsIn-situ construction of electrostatic repulsion between MoS2 interlayers is first proposed to successfully prepare Co-doped monolayer MoS2 under high vapor pressure.The doped Co atoms radically decrease bandgap and lithium ion diffusion energy barrier of monolayer MoS2 and can be transformed into ultrasmall Co nanoparticles (~2 nm) to induce strong surface-capacitance effect during conversion reaction.The Co doped monolayer MoS2 shows ultrafast ion transport capability along with ultrahigh capacity and outstanding cycling stability as lithium-ion-battery anodes.High theoretical capacity and unique layered structures make MoS2 a promising lithium-ion battery anode material. However, the anisotropic ion transport in layered structures and the poor intrinsic conductivity of MoS2 lead to unacceptable ion transport capability. Here, we propose in-situ construction of interlayer electrostatic repulsion caused by Co2+ substituting Mo4+ between MoS2 layers, which can break the limitation of interlayer van der Waals forces to fabricate monolayer MoS2, thus establishing isotropic ion transport paths. Simultaneously, the doped Co atoms change the electronic structure of monolayer MoS2, thus improving its intrinsic conductivity. Importantly, the doped Co atoms can be converted into Co nanoparticles to create a space charge region to accelerate ion transport. Hence, the Co-doped monolayer MoS2 shows ultrafast lithium ion transport capability in half/full cells. This work presents a novel route for the preparation of monolayer MoS2 and demonstrates its potential for application in fast-charging lithium-ion batteries.

Graphite-Based Composite Anodes with C-O-Nb Heterointerfaces Enable Fast Lithium Storage.

To better satisfy the increasing demands for electric vehicles, it is crucial to develop fast-charging lithium-ion batteries (LIBs). However, the fast-charging capability of commercial graphite anodes is limited by the sluggish Li+ insertion kinetics. Herein, we report a synergistic engineering of uniform nano-sized T-Nb2 O5 particles on graphite (Gr@Nb2 O5 ) with C-O-Nb heterointerfaces, which prevents the growth and aggregation of T-Nb2 O5 nanoparticles. Through detailed theoretical calculations and pair distribution function analysis, the stable existence of the heterointerfaces is proved, which can accelerate the electron/ion transport. These heterointerfaces endow Gr@Nb2 O5 anodes with high ionic conductivity and excellent structural stability. Consequently, Gr@10-Nb2 O5 anode, where the mass ratio of T-Nb2 O5 /graphite=10/100, exhibits excellent cyclic stability and incredible rate capabilities, with 100.5 mAh g-1 after 10000 stable cycles at an ultrahigh rate of 20 C. In addition, the synergistic Li+ storage mechanism is revealed by systematic electrochemical characterizations and in situ X-ray diffraction. This work offers new insights to the reasonable design of fast-charging graphite-based anodes for the next generation of LIBs.

A Novel and Flexible Laser Patterned Graphene Nanoplatelet Electrode With SPNs for Fast Charging Lithium-Ion Batteries

A flexible anode was developed with graphene nanoplatelet (xGnP) as the anode material for fabricating fast charging lithium-ion battery. The ink consists of graphene nanoplatelets as active material along with C-45 carbon black as conductive additive and polyvinylidene fluoride (PVDF) as binder. The ink was bar coated on to two flexible copper films to form anodes with mass loadings of 2.8 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 7.2 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Then the anode was laser patterned to introduce secondary pore network (SPN) consisting of pores with a diameter of ~33 μm and an edge-to-edge distance of ~42 μm between the pores. The mass loadings of laser patterned anodes were measured to be 2.1 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 5.6 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Half-cell lithium-ion batteries was assembled with fabricated anodes with lithium metal foil as counter electrode. Ethylene carbonate and dimethyl carbonate (EC: DEC) in 50/50 (v/v) mixed with 1M lithium hexafluorophosphate (LiPF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> ) was used as electrolyte in assembled coin-cells. Formation, rate and cycling tests were performed for bar-coated (without SPN) and laser patterned (with SPN) cells with different mass loadings at different C-rates. Cells with SPNs exhibited higher specific capacities of 420 mAh/g, 315 mAh/g and 207 mAh/g at high mass loading, at fast charging C-rates of 2C, 4C and 6C, respectively. Cells with SPNs showed superior capacity retention close to 90% when compared to cells without SPNs (38%) after 200 cycles at 2C-rate. Effect of SPN’s was significantly evident during rate and cycling performance of anodes at high mass loading. This study demonstrated the significance of implementing SPNs in the electrodes for achieving fast charging lithium-ion batteries with high mass loading.

Ordered-Range Tuning of Flash Graphene for Fast-Charging Lithium-Ion Batteries

Graphene has yet to be mass produced, so practical fast-charging lithium-ion battery (LIB) prototypes based on graphene are scarce. Graphene suffers from long in-plane and reluctant in-depth lithium diffusion due to its defect-free atomic arrangement, resulting in unsatisfactory rate performance as LIB anodes. In this work, combinatorial flash joule heating and ball milling treatment are implemented to enable gram-scale production of graphene in seconds (known as flash graphene, FG) and in-plane ordered-range modulation of graphene architectures. Following the ball milling, the defect-deficient turbostratic FG is transformed to defect-rich cracked FG (CFG), which has shortened ordered ranges and larger interlayer spacings. The CFG anode outperforms FG, commercial carbon black, and graphite electrodes in terms of specific capacity and rate performance due to open channels and shortened pathways for Li+ transport. Moreover, it shows outstanding cycling stability with a high capacity retention of 99% at the 500th cycle. Furthermore, it works well with the LiFePO4 cathode, enabling fast-charging LIB full battery with a state of charge of 77 and 62% at 2C and 4C, respectively. This research on graphene production and structural engineering provides a practical application for the commercial potential of fast-charging LIBs.