Improved Battery Performance Research Articles

Grain-refining Co0.85Se@CNT cathode catalyst with promoted Li2O2 growth kinetics for lithium-oxygen batteries

Highly active cathode catalysts for efficient formation/decomposition of Li2O2 are essential for the performance improvement of lithium-oxygen batteries (LOBs). In this study, a grain-refining Co0.85Se catalyst with a lattice spacing of 2.69 Å of (101) plane closely matching with the (100) plane (2.72 Å) of Li2O2 was applied for high-performance LOBs. Highly (101) plane exposed Co0.85Se@CNT was synthesized by a simple one-pot hydrothermal method. The Co0.85Se with the lattice matching effect not only led to the efficient conversion and polarized growth of Li2O2, but also prevented the formation of byproducts. Density functional theory (DFT) calculations reveal that Co0.85Se (101) plane has the intrinsic catalytic ability to generate/decompose Li2O2 during ORR/OER process, due to its homogeneous electron distribution, suitable adsorption energy, and promoted Li2O2 growth kinetics. As a consequence, the (101) plane highly exposed Co0.85Se@CNT-80 electrode exhibited remarkable cycle stability over 2400 h at 100 mA/g and 290 cycles at 500 mA/g, which is about 2 times longer than other electrodes.

1T-VS2@V2O3 Synergistic Nanoarchitecture-Based Lamellar Clusters as the High Conductivity Cathodes of Thermal Batteries.

Thermal batteries are solid-state, thermally activated batteries with long storage times and high reliability. FeS2 is used as a cathode material commonly, but the high internal resistance and low voltage platform limit the improvement of battery performance. Herein, the 1T-phase vanadium disulfide (VS2) is prepared via the scalable hydrothermal method and applied to thermal battery cathode materials for the first time. 1T-VS2 lamellar flower clusters have high electronic conductivity (1.583 S cm-1) at room temperature, which is 75 times higher than FeS2 (0.021 S cm-1). Mechanism analysis shows that 1T-VS2@V2O3 can be formed based on the part of 1T-VS2 being oxidized to V2O3 at the discharge temperature. Benefiting from the synergistic effect of vanadium sulfide and vanadium oxide as a cathode for thermal batteries enhanced specific capacity (292.4 mA h g-1) and mass energy density (572.5 W h kg-1) when cutoff voltage is 1 V. Additionally, the discharge results indicate that the cells utilizing 1T-VS2 cathodes provided a higher voltage platform of 2.11 V than 1.84 V for FeS2. This impressive work can offer a good strategy for boosting cathode materials for a high-performance thermal battery.

DEST: A Simplified Model and Automated Tool for Loss of Lithium Inventory and Loss of Active Material Estimation in Li‐ion Batteries**

AbstractLi‐ion batteries are attracting an increasing attention due to the process of electrification involving different industrial sectors. Many efforts are dedicated to improving battery performance in terms of cyclability, capacity, fast charging and safety to name a few. Therefore, it is of primal importance to identify and understand the degradation modes that stay behind cell failure. In this sense, Loss of Lithium Inventory (LLI) and Loss of Active Material (LAM) are considered fundamental indicators for estimating the state of health of a cell. In this work, we introduce an automated open tool which is able to return LLI, LAM and voltage drop due to and eventual development of an internal resistance by fitting experimental pseudo‐OCV profiles of a cell, at its beginning and end of life, with a simulated curve obtained from the pseudo‐OCP curves of positive and negative electrodes. The tool is based on a mathematical model consisting in linear transformations that keeps it simple and guarantees for low computational cost. The model is validated against bibliographic dataset and tested on experimental curves from lab‐scale coin and commercial cylindrical cell with different chemistries.

Utilizing Machine Learning Tools for Calm Water Resistance Prediction and Design Optimization of a Fast Catamaran Ferry

The article aims to design a calm water resistance predictor based on Machine Learning (ML) Tools and develop a systematic series for battery-driven catamaran hullforms. Additionally, employing a machine learning predictor for design optimization through the utilization of a Genetic Algorithm (GA) in an expedited manner. Regression Trees (RTs), Support Vector Machines (SVMs), and Artificial Neural Network (ANN) regression models are applied for dataset training. A hullform optimization was implemented for various catamarans, including dimensional and hull coefficient parameters based on resistance, structural weight reduction, and battery performance improvement. Design distribution based on Lackenby transformation fulfills all of the design space, and sequentially, a novel self-blending method reconstructs new hullforms based on two parents blending. Finally, a machine learning approach was conducted on the generated data of the case study. This study shows that the ANN algorithm correlates well with the measured resistance. Accordingly, by choosing any new design based on owner requirements, GA optimization obtained the final optimum design by using an ML fast resistance calculator. The optimization process was conducted on a 40 m passenger catamaran case study that achieved a 9.5% cost function improvement. Results show that incorporating the ML tool into the GA optimization process accelerates the ship design process.

Various Solvent‐Binder Compositions and their Crystalline Phase for Optimal Screen‐Printing of NMC Cathodes

AbstractThis research examines the compatibility and performance of various solvents and binders in the battery cathode fabrication. The study focused on the applicability of solvents, including DMF, NMP, p‐Xylene, Ethanol, Toluene, Cyrene, and KJCMPA, in conjunction with binders such as PVDF #9300, PVDF #1100, HSV 1810, PVP, Oppanol N150, and Oppanol B15 for NMC‐based slurry formulation. Each solvent‐binder combination was evaluated with NMC material, and those demonstrating optimal solubility, adhesion, and film quality were selected for cathode screen‐printing trials. Results show that the combination of NMP solvent and HSV 1810 binder outperformed other pairings in cycling stability and capacity retention, achieving 87 % capacity retention after 1,000 1C/1C cycles. Comprehensive analyses using SEM, XRD, and FTIR offered insights into the structural and binder phase characteristics of the fabricated cathodes, especially the alterations in binder crystallinity phases (α, β, and γ). The data suggest that the use of the homopolymer HSV 1810, irrespective of the solvent, results in a pronounced presence of the γ‐phase within the binder, which subsequently improves battery performance. Moreover, the findings underscore the importance of the solvent‐binder combinations in enhancing battery performance and longevity.

Internal Temperature Estimation of Lithium-Ion Battery Based on Improved Electro-Thermal Coupling Model and ANFIS

Abstract Accurate estimation of the internal temperature of lithium-ion batteries plays an important role in the development of a suitable battery thermal management system, safeguarding the healthy and safe operation of batteries and improving battery performance. In order to accurately estimate the internal temperature of the battery, this paper proposes a method for estimating the internal temperature of lithium-ion batteries based on an improved electro-thermal coupling model and an Adaptive Network-Based Fuzzy Inference System (ANFIS). First, a parameterization method of the electrical model is proposed, and an electrical model whose parameters are affected by temperature and SOC is established. Second, to overcome the complex nonlinear modeling problem of lithium-ion batteries, the ANFIS thermal model is established. Then, an improved electro-thermal coupling model for lithium-ion batteries is established by combining the proposed electrical model and the ANFIS thermal model to improve the accuracy of estimating the internal temperature of the battery. Finally, the effectiveness of the proposed method is verified by simulation and experiment.

Competitive Coordination Structure Regulation in Deep Eutectic Electrolyte for Stable Zinc Batteries.

Rechargeable zinc-based batteries are finding their niche in energy storage applications where cost, safety, scalability matter, yet they are plagued by rapid performance degradation due to the lack of suitable electrolytes to stabilize Zn anode. Herein, we report a competitive coordination structure to form unique quaternary hydrated eutectic electrolyte with ligand-cation-anion cluster. Unraveled by experiment and calculation results, the competing component can enter initial primary coordination shell of Zn2+ ion, partially substituting Lewis basic eutectic ligands and reinforcing cation-anion interaction. The hydration-deficient complexes induced between competing eutectic as hydrogen bond donor-accepter and water also broaden the electrochemical window and confine free water activity. The altered coordination further leads to robust hybrid organic-inorganic enriched solid electrolyte interphase, enabling passivated surface and suppressed dendrite growth. Noticeably, stable Zn plating/stripping for 8000 cycles with high Coulombic efficiencies of 99.6 % and long cycling life of 10000 cycles for Zn-organic batteries are obtained. Even under harsh conditions (small N/P ratio, low temperature), the profits brought by the competitive eutectic electrolyte are still very prominent. This design principle leveraged by eutectic electrolytes with competitive coordination offers a new approach to improve battery performance.

Competitive Coordination Structure Regulation in Deep Eutectic Electrolyte for Stable Zinc Batteries

AbstractRechargeable zinc‐based batteries are finding their niche in energy storage applications where cost, safety, scalability matter, yet they are plagued by rapid performance degradation due to the lack of suitable electrolytes to stabilize Zn anode. Herein, we report a competitive coordination structure to form unique quaternary hydrated eutectic electrolyte with ligand‐cation‐anion cluster. Unraveled by experiment and calculation results, the competing component can enter initial primary coordination shell of Zn2+ ion, partially substituting Lewis basic eutectic ligands and reinforcing cation‐anion interaction. The hydration‐deficient complexes induced between competing eutectic as hydrogen bond donor‐accepter and water also broaden the electrochemical window and confine free water activity. The altered coordination further leads to robust hybrid organic‐inorganic enriched solid electrolyte interphase, enabling passivated surface and suppressed dendrite growth. Noticeably, stable Zn plating/stripping for 8000 cycles with high Coulombic efficiencies of 99.6 % and long cycling life of 10000 cycles for Zn‐organic batteries are obtained. Even under harsh conditions (small N/P ratio, low temperature), the profits brought by the competitive eutectic electrolyte are still very prominent. This design principle leveraged by eutectic electrolytes with competitive coordination offers a new approach to improve battery performance.

Solvation Structure and Derived Interphase Tuning for High‐Voltage Ni‐Rich Lithium Metal Batteries with High Safety Using Gem‐Difluorinated Ionic Liquid Based Dual‐Salt Electrolytes

AbstractStabilizing electrolytes for high‐voltage lithium metal batteries (LMBs) is crucial yet challenging, as they need to ensure stability against both Li anodes and high‐voltage cathodes (above 4.5 V versus Li/Li+), addressing issues like poor cycling and thermal runaway. Herein, a novel gem‐difluorinated skeleton of ionic liquid (IL) is designed and synthesized, and its non‐flammable electrolytes successfully overcome aforementioned challenges. By creatively using dual salts, fluorinated ionic liquid and dimethyl carbonate as a co‐solvent, the solvation structure of Li+ ions is efficiently controlled through electrostatic and weak interactions that are well unveiled and illuminated via nuclear magnetic resonance spectra. The as‐prepared electrolytes exhibit high security avoiding thermal runaway and show excellent compatibility with high‐voltage cathodes. Besides, the solvation structure derives a robust and stable F‐rich interphase, resulting in high reversibility and Li‐dendrite prevention. LiNi0.6Co0.2Mn0.2O2/Li LMBs (4.5 V) demonstrate excellent long‐term stability with a high average Coulombic efficiency (CE) of at least 99.99 % and a good capacity retention of 90.4 % over 300 cycles, even can work at a higher voltage of 4.7 V. Furthermore, the ultrahigh Ni‐rich LiNi0.88Co0.09Mn0.03O2/Li system also delivers excellent electrochemical performance, highlighting the significance of fluorinated IL‐based electrolyte design and enhanced interphasial chemistry in improving battery performance.

The critical role of in-situ lithium fluoride in gel polymer electrolyte for high-performance rechargeable batteries

Lithium-ion (Li-ion) batteries are continuously being developed to enhance safety and energy density. One promising approach involves combining high nickel cathode material (NCM811) with Gel Polymer Electrolyte (GPE). However, achieving compatibility between these components remains a challenge. In this study, we investigate the use of Ethyl difluoroacetate (DFEA) to enhance the mechanical stability, ionic conductivity, and heat-resisting of polyethylene glycol dimethacrylate (PEGDMA) based GPE, thereby improving battery performance. The modified GPE/DFEA exhibits a smoother surface, increased Young's modulus (2.2 GPa), and high ionic conductivity (7.10 mS cm−1). Additionally, it enables the in-situ formation of a LiF-rich interface film on the electrode/electrolyte surfaces. Moreover, the Li||Li symmetrical cell with GPE/DFEA demonstrates stable cycling for 500 h without dendrite growth. Furthermore, Li|Cu asymmetrical cells using GPE/DFEA achieve an average Coulombic efficiency (CE) of 99.0% over 200 cycles at 1 mA cm−2, compared to only 62.2% for liquid electrolyte (LE). Importantly, the GPE/DFEA allows for operation beyond the conventional voltage limit of 4.25 V, reaching 4.38 V. It is successfully implemented in an Ah-level NCM811/graphite pouch cell, resulting in an energy density of 250 Wh/kg and improved cycle stability at 45 °C compared to standard electrolytes. Moreover, the GPE/DFEA-based batteries exhibit enhanced safety performance under conditions such as needle puncture and overcharge. The developed GPE can meet the practical requirements for battery applications.

Hierarchically interconnected WS2/graphene foam for high-performance sodium storage

Sodium-ion batteries (SIBs), as the promising energy storage systems alternative to lithium-ion batteries (LIBs), are given increasing expectations and highly valued owing to the abundant reserves and low cost of sodium-containing minerals. However, further applications are still limited by the lack of anode material with high capacity and long cycle life. Herein, highly permeable foam-like tungsten disulfide/reduced graphene oxide composites with 3D interconnected hierarchical porous structure (3DHP WS2/RGO) are designed and studied as anode materials in SIBs. Remarkably improved battery performance is obtained, including high reversible capacity (419 mA h g−1 at 100 mA g−1), excellent cycling stability (1000 cycles) and superior rate capability (360 mA h g−1 at 2 A g−1). Electrochemical characterizations reveal that the high pseudocapacitive behavior dominates the fast ions/charge reaction kinetics, and the reversible conversion between Na2S generated in the first discharge process and S as evidenced by various advanced characterization techniques dominates sodium storage. The exceptional performance exhibited by 3DHP WS2/RGO composite sheds new light on the development of two-dimensional transition metal dichalcogenides-based materials for next-generation energy storage systems.

Introduced Hierarchically Ordered Porous Architecture on a Separator as an Efficient Polysulfide Trap toward High-Mass-Loading Li-S Batteries.

The severe shuttle effect and the depletion of active sulfur result in performance deterioration, presenting two formidable issues that must be overcome to achieve high-mass-loading lithium-sulfur batteries. Herein, we reported a composite separator by introducing carbon photonic crystals with a hierarchically ordered porous structure on a commercial separator. The ordered structure and interconnected hierarchical macro-meso-micropore network of the composite separator facilitate efficient trapping of polysulfides and rapid transport of lithium ions. The high ion diffusivity promotes the conversion of polysulfides enhancing sulfur utilization and mitigating the occurrence of "dead sulfur" on the surface of the separator. Impressively, under a high sulfur loading of 3 mg cm-2, the lithium-sulfur battery with the composite separator displayed a high reversible capacity of 1582 mA h g-1 at 0.1 C and an excellent long-term cycling performance with a decay rate of as low as 0.033% per cycle over 1500 cycles at 1 C. Surprisingly, the battery represented a high reversible capacity of 935 mA h g-1 at 0.2 C even at a sulfur loading of 6.71 mg cm-2. The design of the composite separator underscores the pivotal role of carbon architecture in improving battery performance and brings a bright prospect to enable the commercialization of high-mass-loading lithium-sulfur batteries.

Developing an abnormal high-Na-content P2-type layered oxide cathode with near-zero-strain for high-performance sodium-ion batteries.

Layered transition metal oxides (NaxTMO2) possess attractive features such as large specific capacity, high ionic conductivity, and a scalable synthesis process, making them a promising cathode candidate for sodium-ion batteries (SIBs). However, NaxTMO2 suffer from multiple phase transitions and Na+/vacancy ordering upon Na+ insertion/extraction, which is detrimental to their electrochemical performance. Herein, we developed a novel cathode material that exhibits an abnormal P2-type structure at a stoichiometric content of Na up to 1. The cathode material delivers a reversible capacity of 108 mA h g-1 at 0.2C and 97 mA h g-1 at 2C, retaining a capacity retention of 76.15% after 200 cycles within 2.0-4.3 V. In situ diffraction studies demonstrated that this material exhibits an absolute solid-solution reaction with a low volume change of 0.8% during cycling. This near-zero-strain characteristic enables a highly stabilized crystal structure for Na+ storage, contributing to a significant improvement in battery performance. Overall, this work presents a simple yet effective approach to realizing high Na content in P2-type layered oxides, offering new opportunities for high-performance SIB cathode materials.

Enhancing ionic conductivity and suppressing Li dendrite formation in lithium batteries using a vinylene-linked covalent organic framework solid polymer electrolyte

A novel solid polymer electrolyte based on chemically stable vinylene-linked covalent organic framework was developed, demonstrating enhanced Li+ conductivity and improved battery performance.

Electrocatalysts work better in lean-electrolyte lithium–sulfur batteries

The cathode kinetics promotion effectiveness of electrocatalysts is evaluated in lean-electrolyte lithium–sulfur batteries. The improvement of polysulfide conversion kinetics and battery performance is more significant at higher sulfur concentration.

Recent Advances and Perspectives of Covalent Organic Frameworks for Alkali-Ion Batteries

Covalent organic frameworks (COFs), a novel class of crystalline porous materials constructed by covalent bonds, possess ordered porous structures via thermodynamically controlled polymerization reactions. Because of their structurally diverse, regular pore structures, high surface area, and thermal stability can be functionally tailored through different synthetic methods to meet the needs of various applications including for secondary batteries. This review summarized recent efforts that have been devoted to designing and synthesizing COF-based materials for battery applications, including electrode materials, electrolytes, and separators. Unique characteristics of COFs allow for the rational design of targeted functions, suppression of side reactions, and promotion of ion transport for batteries. This review clarified recent research progress on COF materials for lithium-ion batteries, lithium–sulfur batteries, sodium-ion batteries, potassium-ion batteries and so on. This review pointed out the structure and chemical properties of COFs, as well as new strategies to improve battery performance. Furthermore, we concluded the major challenges and future trends of COF materials in electrochemical applications. It is hoped that this review will provide meaningful guidance for the development of COFs for alkali-ion batteries.

Improvement of the rate capability of all-solid-state cells with Fe-based polysulfide positive electrode materials by modifying the microstructure.

We successfully prepared an Fe- and Li-containing polysulfide positive electrode material (Li8FeS5-Li2FeS2 composite) that shows a high specific capacity (>500 mA h g-1) with improved rate capability in all-solid-state cells. High-resolution TEM analysis indicated the coexistence of small crystallites of high-conductivity Li2FeS2 and FeS, as well as low-crystallinity Li2S, in the composite, and this microstructure is responsible for the improved battery performance.

MXene- and MOF-based single-atom catalysts for next-generation batteries chemistry: A synergy of experimental and theoretical insights

Metal-ion batteries (MIBs) play pivotal roles in various energy storage applications, necessitating the continuing advancement of materials and technologies that enhance their performance. In recent years, single atoms (SAs) on MXene and MOF-derived SAs have emerged as promising candidates for revolutionizing MIBs, metal-chalcogenide (MCBs), and metal-air batteries (MABs). These catalysts possess unique atomic-level structures and remarkable electrochemical properties, showcasing significant potential for improving energy density, cycling life, and charge/discharge efficiency. This review focuses on the principles, synthesis strategies, performance, and potential applications of MXene- and MOF-based SA catalysts for use in MIB-based energy-storage applications by highlighting MIB-catalyst challenges and advancements and emphasizing their significance for enhancing battery performance. We discuss how MXene- and MOF-based SA catalysts (SACs) contribute to improving MIB, MCB, and MAB performance, as well as how these catalysts enhance electrochemical parameters such as energy density, cycling life, and charge/discharge efficiency. Furthermore, theoretical reaction-mechanism investigations are presented, shedding light on the underlying processes that contribute to improved battery performance. Moreover, practical implications, existing challenges, and potential future research directions are discussed, thereby highlighting the promising applications of SAs on MXene and MOF-derived SACs for use in electrochemical energy storage systems.

A DOD-SOH balancing control method for dynamic reconfigurable battery systems based on DQN algorithm

This article presents a DOD-SOH equalization method for a DRB system based on the Deep DQN algorithm. The proposed method utilizes DQN to learn the operational processes of the system. By integrating the advantages of DRB with SOH equalization theory and the DQN algorithm from the perspective of DOD, our method significantly improve battery performance and ensure cell balancing. To begin with, we present a dynamic reconfigurable battery system with a simple topological structure and outline its switching control process. Additionly, we provide an analysis of the SOH balancing principle and elaborate on the control process of DQN algorithm. Finally, subsequent simulations are carried out, and the simulation results demonstrate outstanding performances in reducing the variance of SOHs, which indicates an enhancement in the level of SOH balancing as well.

Solid Electrolyte Coated NCM523 for Composite Cathode in All-Solid-State Batteries

All-solid-state battery using sulfide solid electrolyte has advantages such as high lithium ionic conductivity and wide electrochemical stability window. Although it is attracting great attention in that it is capable of high power and high energy density, there are problems to be improved.Organic liquid electrolytes in conventional lithium ion batteries have excellent wettability and can form uniform lithium ion transfer channels in electrodes. However, in the case of all-solid-state battery, the formation of a solid-solid interface is limited due to the solid characteristics. In addition, the degradation of the interfacial contact between the active material and solid electrolyte in the composite electrode due to the volume change of the active material with (de)-intercalation of lithium ion during cycling causes loss of the lithium ionic pathway and deterioration of cell performance. This study focuses on improving battery performance by coating the surface of active material with solid electrolyte to maintain an even lithium ion transfer path in the composite electrode. The solid electrolyte coating of the active material has a decisive effect on the electrochemical behavior of the cell because it affects the formation of smooth lithium ionic pathway and suppression of voids in the composite electrode. Therefore, the focus of this study is to confirm the formation of uniform solid electrolyte coating layer according to the size of the solid electrolyte.Therefore, the particle size of the solid electrolyte was diversified using a liquid-phase process and a dispersant, and the solid electrolyte coating was performed using a dispersion process. It was confirmed that an even solid electrolyte coating layer was formed as the particles size of the solid electrolyte decreased, and the electrochemical performance was improved due to the solid electrolyte coating layer. In addition, it was confirmed that the lithium ionic pathway was maintained even after long cycling with the solid electrolyte coating layer, and also the side reactions occurred less according to the homogeneous electrochemical reaction.