Li-ion Batteries Research Articles

Geometric Design of Interface Structures and Electrolyte Solvation Chemistry for Fast Charging Lithium‐Ion Batteries

AbstractThe grain sizes of solid electrolyte interphase (SEI) and solvation structure of electrolytes can affect Li+ ion transport across SEI and control the desolvation kinetics of solvated Li+ ions during fast‐charging of Li‐ion batteries (LIBs). However, the impact of the geometric structure of SEI grains on the fast charging capability of LIBs is rarely examined. Here, the correlation between the SEI grain size and fast charging characteristics of cells is explored, and the desolvation kinetics is controlled by replacing the strongly binding ethylene carbonate (EC) solvent with a weakly binding nitrile‐based solvent under fast charging conditions. The evolution of small grains of SEI to provide sufficient paths for Li+ ion supply can be achieved by the modification of solvation structure in the electrolyte. Additionally, the less resistive SEI composition and low viscosity of isoBN‐containing electrolyte enable a more rapid charging of LiNi0.8Co0.1Mn0.1O2/graphite full cells by facilitating the SEI crossing of Li+ ions with less Li plating at a charging rate of 4 C at 25 °C. This work sheds light on solvation structure and interface engineering to enhance the fast charging cycle stability of LIBs for tailorable adoption in transportation sectors.

Electrolytes Based on Mixed Ionic Liquid-Carbonate Solvents for Silicon Anodes in Li-Ion Batteries

Abstract In this work, mixtures of ionic liquid pyrrolidinium bis(fluorosulfonyl)imide (PYR13FSI) and the carbonate solvents dimethyl carbonate (DMC) and fluoroethylene carbonate (FEC) with lithium bis(fluorosulfonyl)imide (LiFSI) salt have been evaluated as electrolytes for anodes made from micron-sized metallurgical grade silicon. The electrolytes were characterized with respect to thermal and transport properties. Electrochemical performance was assessed in pseudo-full cells with a silicon anode and a commercial oversized LiFePO4 cathode. They were then compared to electrolytes made with only PYR13FSI or carbonates as solvents. 
The addition of DMC and FEC to the PYR13FSI resulted in a minor increase in the glass transition temperature, T_g. No change of state was observed for the mixed electrolytes in the differential scanning calorimetry traces up to 100℃, showing that a wide temperature window was maintained. The conductivity of the mixed electrolytes was slightly improved compared to that of the pure LiFSI:PYR13FSI. The best rate performance was obtained with the electrolyte containing both DMC and FEC, which was attributed to the superior solid electrolyte interphase-forming properties of this electrolyte. Cycling within a limited voltage window of 2.4-3.4 V with a limited initial capacity was necessary to attain satisfactory cycling stability.

In Situ Synthesis of Phosphate-Based CelloMOF as a Promising Separator for Li–Ion Batteries

In Situ Synthesis of Phosphate-Based CelloMOF as a Promising Separator for Li–Ion Batteries

The RUL Prediction of Li-Ion Batteries Based on Adaptive LSTM

With the widespread adoption of electric vehicles and energy storage systems, predicting the remaining useful life (RUL) of lithium-ion batteries (LIBs) is critical for enhancing system reliability and enabling predictive maintenance. Traditional RUL prediction methods often exhibit reduced accuracy during the nonlinear aging stages of batteries and struggle to accommodate complex degradation processes. This paper introduces a novel adaptive long short-term memory (LSTM) approach that dynamically adjusts observation and prediction horizons to optimize predictive performance across various aging stages. The proposed method employs principal component analysis (PCA) for dimensionality reduction on publicly available NASA and Mendeley battery datasets to extract health indicators (HIs) and applies K-means clustering to segment the battery lifecycle into three aging stages (run-in, linear aging, and nonlinear aging), providing aging-stage-based input features for the model. Experimental results show that, in the NASA dataset, the adaptive LSTM reduces the MAE and RMSE by 0.042 and 0.043, respectively, compared to the CNN, demonstrating its effectiveness in mitigating error accumulation during the nonlinear aging stage. However, in the Mendeley dataset, the average prediction accuracy of the adaptive LSTM is slightly lower than that of the CNN and Transformer. These findings indicate that defining aging-stage-based adaptive observation and prediction horizons for LSTM can effectively enhance its performance in predicting battery RUL across the entire lifecycle. Conflict of Interest Statement The authors declare no conflicts of interest.

Improving the fast-charging capability of NbWO-based Li-ion batteries

The discovery of Nb-W-O materials years ago marks the milestone of charging a lithium-ion battery in minutes. Nevertheless, for many applications, charging lithium-ion battery within one minute is urgently demanded, the bottleneck of which largely lies in the lack of fundamental understanding of Li+ storage mechanisms in these materials. Herein, by visualizing Li+ intercalated into representative Nb16W5O55, we find that the fast-charging nature of such material originates from an interesting rate-dependent lattice relaxation process associated with the Jahn-Teller effect. Furthermore, in situ electron microscopy further reveals a directional, [010]-preferred Li+ transport mechanism in Nb16W5O55 crystals being the “bottleneck” toward fast charging that deprives the entry of any desolvated Li+ through the prevailing non-(010) surfaces. Hence, we propose a machine learning-assisted interface engineering strategy to swiftly collect desolvated Li+ and relocate them to (010) surfaces for their fast intercalation. As a result, a capacity of ≈ 116 mAh g−1 (68.5% of the theoretical capacity) at 80 C (45 s) is achieved when coupled with a Li negative electrode.

Deciphering Interfacial Stability of Sulfide and Halide-Based Electrolytes via Operando X-ray Photoelectron Spectroscopy.

Combined solid electrolytes address cathode-anode compatibility in all-solid-state Li-ion batteries (ASSLBs), yet interface stability and ion transport mechanisms between different electrolytes remain unclear. Herein, we investigate Li6PS5Cl (LPSC), Li3InCl6 (LIC), and Li1.75ZrO0.5Cl4.75 (LZOC) composite electrolytes through electrochemical analysis and operando X-ray photoelectron spectroscopy. Our results reveal that the electrostatic potential difference between LPSC and LIC inhibits Li+ migration, leading to the decomposition of LIC into InCl3 and LiCl, causing battery failure. In contrast, LZOC forms an oxygen-rich interphase with LiCoO2 (LCO), showing better interfacial stability. The electrostatic potential difference between LZOC and LPSC promotes Li+ diffusion, maintaining interface stability even as LPSC decomposes, thereby preventing severe degradation of LZOC. Therefore, the LCO-LZOC composite cathode exhibits better electrochemical performance than LCO-LIC. This study elucidates the basic mechanism of interfacial reaction and ion diffusion in sulfide-halide electrolytes and emphasizes the key role of electrolyte compatibility in ASSLBs failure pathways.

One-Pot Bottom-Up Synthesis of SiO2 Quantum Dots and Reduced Graphene Oxide (rGO) Nanocomposite as Anode Materials in Lithium-Ion Batteries

Here, crystalline SiO2 quantum dots (QDs) of 3–5 nm size were grown within the layers of reduced graphene oxide (rGO) by a solution mode chemical growth process at a relatively low temperature (100 °C). The composite was applied as a negative electrode in a Li-ion half-cell battery and the electrochemical investigation confirmed a distinct first-cycle discharge/charge capacity (~865 mAhg−1/387 @ 51 mAg−1). The battery could retain a capacity of 296 mAhg−1 after 60 charge/discharge cycles with 99% coulombic efficiency. Furthermore, at a high current rate of 1.02 Ag−1, the battery was able to display an apparent rate capability (214.47 mAhg−1), indicating the high chemical and mechanical stability of the composite at a high current rate. A structural analysis revealed clear distinct diffraction peaks of SiO2 and high-resolution transmission electron microscopy images showed discrete atomic planes, thereby confirming the growth of crystalline SiO2 QDs within the layers of rGO.

Onset of Lithium Plating in Fast-Charging Li-Ion Batteries

Onset of Lithium Plating in Fast-Charging Li-Ion Batteries

Tuning Li occupancy and local structures for advanced Co-free Ni-rich positive electrodes

Structure evolution and surface reactivity have long been regarded as the most crucial points for studying Ni-rich positive electrodes for Li-ion batteries. Unfortunately, the influence of Li occupancy as a single factor on electro-chemomechanical stability has been overlooked and is missing, owing to the challenge of Li determination in the lattice. Here, a comprehensive analysis reveals different Li occupancies and related structural domains (Ni/Li exchange, LiaXOb, Li/Mn/X(Ni) ordering domains, X = Nb5+, W6+, and Mo6+) by using a combination of Li-sensitive characterization techniques. By introducing a Li-regulation strategy, the relative ratio of each domain is effectively tuned in the Ni-rich positive electrodes. Through tuning, two specific positive electrodes are designed, exhibiting notable improvement in battery cyclability. The specific Li structural units induce significant changes in redox mechanisms. This Li-occupancy-tuning approach highlights the necessity of focusing on Li distribution and opens up ideas for designing advanced Ni-rich positive electrodes with high durability.

Designing Two-Dimensional Graphullerene C36 as High-Performance Anode Materials for Li-Ion Batteries: A First-Principles Study

Designing Two-Dimensional Graphullerene C₃₆ as High-Performance Anode Materials for Li-Ion Batteries: A First-Principles Study

Exploring the Solubility of Ethylene Carbonate in Supercritical Carbon Dioxide: A Pathway for Sustainable Electrolyte Recycling from Li-Ion Batteries

Ethylene carbonate is, among other applications, used in Li-ion batteries as an electrolyte solvent to dissociate Li-salt. Supercritical CO2 extraction is a promising method for the recycling of electrolyte solvents from spent batteries. To design an extraction process, knowledge of the solute solubility is essential. In this work, the solubility of ethylene carbonate at different pressure (80–160 bar) and temperature (40 °C, and 60 °C) conditions is studied. It is shown that the solubility of ethylene carbonate increased with pressure at both temperatures, ranging from 0.24 to 8.35 g/kg CO2. The retrieved solubility data were fitted using the Chrastil model, and the average equilibrium association number was determined to be 4.46 and 4.02 at 40 °C and 60 °C, respectively. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction analysis of the collected ethylene carbonate indicated that the crystal morphology and structure remained unchanged. A proof-of-principle experiment showed that EC can be successfully extracted from Li-ion battery waste at 140 bar and 40 °C.

High-Energy Density Li-Ion Battery Cathode Using Only Industrial Elements.

Li-ion batteries are crucial for the global energy transition to renewables; however, their scalability is limited by the supply of key elements used in commercial cathodes (e.g., Ni, Mn, Co, P). Therefore, there is an urgent need for next-generation cathodes composed of widely available and industrially scalable elements. Here, we introduce a Li-rich cathode based on the known material Li2FeS2, composed of low-cost elements (Al, Fe, S) that are globally mined and refined at an industrial scale. The substitution of redox-inactive Al3+ for Fe2+ achieves remarkably high degrees of anion redox, which, in turn, yields high gravimetric capacity (≈450 mAh·g-1) and energy density (≳1000 Wh·kg-1). We show that Al3+ enables high degrees of delithiation by stabilizing the delithiated state, suppressing phase transformations that would otherwise prevent deep delithiation and extensive anion redox. This mechanistic insight offers new possibilities for developing scalable, next-generation Li-ion battery cathodes to meet pressing societal needs.

Machine learning configurations for state of charge predictions of Li-ion batteries

Abstract This work investigates the development of a Nonlinear Autoregressive with Exogenous Input (NARX) Artificial Neural Network (ANN) model to predict the dynamic State-of-Charge (SOC) of a Li-ion battery (LIB) using voltage and Electrochemical Impedance Spectroscopy (EIS) data. To optimize the model’s performance, extensive ANN parameter adjustments were investigated and various data structuring techniques were explored. It was found that directly inputting all EIS data corresponding to different SOC levels led to a significant decrease in predictive accuracy. Specifically, the root mean square error (RMSE) for SOC prediction increased by approximately 40% when using frequency-separated EIS data. In contrast, utilizing EIS data from a specific SOC level (0%) significantly improved the model’s performance. By selectively excluding input features with lower input–output correlation, the RMSE was reduced by 62%, outlining the significant advantage of using EIS measured at 0% SOC. This result highlights the importance of careful data selection and preprocessing in enhancing the accuracy and efficiency of NN-based SOC estimation. The findings of this study provide valuable insights into the optimal data structuring and feature selection strategies for developing accurate and efficient NN models for battery SOC prediction. Graphical abstract

Restoration of Degraded Spinel Structure from Spent Li-Ion Battery Cathodes towards Reclaiming for Second Life

Restoration of Degraded Spinel Structure from Spent Li-Ion Battery Cathodes towards Reclaiming for Second Life

Double-Network Aerogel-Based Composite Phase Change Material Inspired by Beaver Damming for All-Weather Thermal Management of Lithium Batteries.

Phase change materials (PCMs) have shown significant potential in enhancing the thermal regulation of lithium-ion (Li-ion) batteries. However, existing organic solid-liquid PCMs encounter several issues, including leakage, limited energy density, and an inability to fulfill the demands of comprehensive thermal management across various environmental conditions. This study takes inspiration from beavers, which construct dams to regulate the temperature of their habitats in different climates, and introduces a dual-network aerogel-based composite PCM (CPCM) designed for the all-weather thermal control of Li-ion batteries. The developed CPCM incorporates tetradecanol (TD) as the core phase change material, a poly(vinyl alcohol)/carboxylated cellulose nanocrystal (PVA/CNC-C) aerogel as the potting material, borax for cross-linking, and graphene nanoplatelets (GNPs) to facilitate photothermal conversion. This CPCM demonstrates a high energy density of 199.1 J/g and remarkable cyclic durability. Furthermore, it features excellent shape retention, superior mechanical strength, and an impressive photothermal conversion efficiency of 94.5%. In addition, the CPCM effectively regulates the thermal behavior of Li-ion batteries: at elevated temperatures, it ensures that the battery's maximum operating temperature remains below 55 °C, while at lower temperatures, it maintains the battery above 10 °C for 30-40 min. Moreover, it possesses the capability to preheat batteries, enhancing their functionality in cold environments. This research presents an innovative approach to designing materials that address the comprehensive thermal management needs of Li-ion batteries under varying climatic conditions.

Noble metal (Pd, Pt)-functionalized WSe2 monolayer for adsorbing and sensing thermal runaway gases in LIBs: A first-principles investigation.

Noble metal (Pd, Pt)-functionalized WSe2 monolayer for adsorbing and sensing thermal runaway gases in LIBs: A first-principles investigation.

Self-supporting Mg-Sn alloy anode for high-energy Li-ion batteries

Self-supporting Mg-Sn alloy anode for high-energy Li-ion batteries

High-capacity Ni-rich composite cathodes having chemically fused interface with Li3InCl6 electrolyte towards low-pressure operating all-solid-state Li-ion batteries

High-capacity Ni-rich composite cathodes having chemically fused interface with Li3InCl6 electrolyte towards low-pressure operating all-solid-state Li-ion batteries

Unique leaching behavior of Si oxide impurity and its consequence for resynthesized cathode active materials in Li-ion batteries

Unique leaching behavior of Si oxide impurity and its consequence for resynthesized cathode active materials in Li-ion batteries

A novel approach for accurate SOC estimation in Li-ion batteries in view of temperature variations

A novel approach for accurate SOC estimation in Li-ion batteries in view of temperature variations