Cycling Performance Of Lithium Ion Batteries Research Articles

Enhancement of Low-Temperature Cycling Performance of Lithium-Ion Batteries by use of Dual Cosolvent

Abstract Lithium-ion batteries (LIBs) based on conventional electrolyte suffer from poor cycling performance at low temperatures due to the reduced ionic conductivity of electrolytes, sluggish charge transfer reaction, and Li plating during the charging process. Herein, we propose a dual cosolvent composed of methyl acetate (MA) and ethyl fluoroacetate (EFA). MA effectively reduced the viscosity of the electrolyte, improving the ionic conductivity at low temperatures. EFA facilitated the de-solvation of Li+ ions and formed an anion-derived solvation structure, enabling the formation of an inorganic-rich solid electrolyte interphase on the graphite anode. Due to the synergistic effect of MA and EFA, the graphite/LiFePO4 cell employing a dual cosolvent exhibited good cycling performance at low temperatures, delivering a discharge capacity of 68.7 mAh g-1 at -20 °C and 0.2 C and showing a capacity retention of 99.7% after 100 cycles at -20 °C and 0.33 C. Additionally, the cell exhibited an initial discharge capacity of 131.2 mAh g-1 at 25 °C and 1.0 C, with a capacity retention of 99.4% after 300 cycles. Our results demonstrate that liquid electrolytes containing dual cosolvent with various beneficial roles can be a promising solution for improving the low-temperature cycling performance of LIBs.

Robust silicon/carbon composite anode materials with high tap density and excellent cycling performance for lithium-ion batteries

Achieving high density while ensuring structural stability and low volume expansion during cycling remains challenging for Si-based anode materials in lithium-ion batteries (LIBs). Herein, we introduce a novel approach to address this issue by developing high tap-density carbon-coated sub-nano-Si-embedded activated carbon (ACSC) anode materials. The resulting ACSC exhibits an ultra-high true density exceeding 0.99 g cm−3 and a Si content of 48 % (abbreviated as ACS0.48C), leading to an impressive volumetric capacity of 2182 mA h cm−3. Despite the high tap density and Si content of ACS0.48C, the ACS0.48C/artificial graphite (ACS0.48C/AG) mixture demonstrates a remarkable capacity retention rate of 97.9 % after 200 cycles at 0.5 C, with a modest volume expansion rate of 7.3 % after 50 cycles. The outstanding electrochemical performance can be attributed to the structural stability of ACS0.48C throughout cycling. The AC scaffold provides a robust mechanical framework to prevent volume expansion and agglomeration of sub-nano-sized Si particles. Furthermore, the homogeneous mixing of amorphous Si and carbon at the atomic level ensures isotropic expansion, thereby enhancing structural stability. The unique structure of ACS0.48C, combining high tap density and superior cycling performance, offers a solution to the low tap density issue in nanostructures and introduces innovative concepts for the morphology and structural design of Si/C secondary particles.

Chemical prelithiation of SiOx/Gr anode for improved cycling performance in lithium-ion batteries

Owing to its high specific capacity and excellent cycling performance, SiOx is an appealing alternative to traditional graphite anodes. In order to increase the anode's cycling stability, this work demonstrates the chemical prelithiation of SiOx/Gr anode for real-world applications. The highest ICE obtained is 98.8 % using the chemical prelithiation method for half cell. The prelithiated anode was characterized using various techniques, and the viability of the process was tested using a pouch cell assembly, demonstrating enhanced capacity compared to the pristine pouch cell. This research has implications for portable electronics, electric vehicles, renewable energy storage, and other applications requiring high-capacity and long-lasting batteries.

Over‐ and Hyper‐Lithiated Oxides as Sacrificial Cathodes for Lithium‐Ion Batteries

AbstractBy incorporating sacrificial lithium (Li) sources during electrode fabrication, researchers aim to address the challenge of initial capacity loss due to the formation of a solid electrolyte interphase layer during the early cycles of lithium‐ion batteries (LIBs). This research contributes to the augmentation of Li+ inventory within the electrode to compensate for the irreversible loss of Li+, thereby enhancing the reversibility and cycling performance of LIBs. There are various types of pre‐lithiation additives; however, this perspective specifically discusses over‐ and hyper‐lithiated oxide materials. Within these oxides, research directions are characterized by contrasting approaches aimed at either enhancing the reversibility or inducing the irreversibility of these materials. Intriguingly, both opposing approaches align with the common objective of increasing the energy density of LIBs by providing surplus Li+ to compensate for irreversible Li+ consumption. From this perspective, a concise overview of diverse pre‐lithiation methodologies is provided and the reaction mechanisms associated with over‐ and hyper‐lithiated oxides as sacrificial cathode additives for pre‐lithiation are investigated. Subsequently, strategies to modulate the electrochemical properties of these oxides for practical use in sacrificial cathodes are briefly explored. Following this, discussions are carried out and perspectives on research that adopts the aforementioned contrasting directions are presented.

Enhanced cycling performance of lithium-ion batteries with V2O5 as cathode by Co-doping for structural stability

Enhanced cycling performance of lithium-ion batteries with V2O5 as cathode by Co-doping for structural stability

Single and binary nickel, copper, and zinc-based nanosized oxides as anode materials in lithium-ion batteries

The demand for portable power sources with higher energy density and longer lifespan has prompted researchers to focus on developing better electrode materials for lithium-ion batteries (LIBs). Metal oxide nanoparticles have potential due to their low cost, high surface-area-to-volume ratio, strong reactivity, excellent size distribution, high theoretical capacities, and eco-friendly synthesis methods. However, there is still room for improvement in capacity retention and rate performance. To cope with this entail, the cycle performance of LIBs has been initially investigated utilizing single metal oxide anode materials including NiO, CuO, and ZnO nanostructures. Subsequently, binary oxides of Ni–Cu, Ni–Zn, and Cu–Zn have been synthesized to examine whether the binary structures boost the battery performance. NiCuO is the optimum anode material combining the benefits of NiO with the highest initial discharge capacity of 691 mAh g-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} and the highest retention rate of CuO (49% after 30 cycles).

The efficient solid electrochemical corrosion prelithiation of graphite and SiOx/C anodes for longer-lasting lithium ion batteries

In order to avoid side reactions with liquid electrolyte for the prelithiation method using metal lithium for the improvement of initial coulombic efficiency and prelithiation efficiency, we propose the solid electrochemical corrosion (SEC) of lithium replacing liquid electrolyte with solid electrolyte of lithium phosphorus oxynitride (LiPON) in previous works. However, the low prelithiation rate of solid electrochemical corrosion with LiPON interlayer between anode and lithium hinders its possible large-scale application. Here, an ultrathin film of Bi2O3 is introduced as the interface layer to improve the prelithiation rate of SEC, the prelithiation effects are investigated on both graphite and SiOx/C anodes by morphological, spectroscopic and electrochemical characterizations. The initial coulombic efficiencies of graphite and SiOx/C anodes can be respectively increased by about 5.1% and 9.7% after the prelithiation. The prelithiation efficiency values are as high as 79.3% for graphite and 86.7% for SiOx/C with SEC prelithiation. Our results demonstrate that SEC prelithiation with Bi2O3 interface layer could be applied to improve the capacity and cycling performance of lithium-ion batteries.

Nanostructure and doping effects of a-Si:H and μc-Si:H anode in lithium-ion battery performance

The charge/discharge capacity and cycle performance of lithium-ion batteries (LIBs) are studied in terms of the nanostructure of silicon-based anode materials and doping. The anode material is chosen to be either hydrogenated amorphous silicon (a-Si:H) or hydrogenated microcrystalline silicon (μc-Si:H), in which the doping is controlled between non-doped intrinsic i-type and phosphorous-doped n-type. The results show that a LIB test cell composed of a n-type a-Si:H anode yields a higher performance. The specific capacity during discharge is obtained initially at 2478 mAh/g, 1940 mAh/g after 10 cycles, and 1360 mAh/g after 40 cycles under a 0.2C condition.

A critical review on composite solid electrolytes for lithium batteries: Design strategies and interface engineering

The rapid development of new energy vehicles and 5G communication technologies has led to higher demands for the safety, energy density, and cycle performance of lithium-ion batteries as power sources. However, the currently used liquid carbonate compounds in commercial lithium-ion battery electrolytes pose potential safety hazards such as leakage, swelling, corrosion, and flammability. Solid electrolytes can be used to mitigate these risks and create a safer lithium battery. Furthermore, high-energy density can be achieved by using solid electrolytes along with high-voltage cathode and metal lithium anode. Two types of solid electrolytes are generally used: inorganic solid electrolytes and polymer solid electrolytes. Inorganic solid electrolytes have high ionic conductivity, electrochemical stability window, and mechanical strength, but suffer from large solid/solid contact resistance between the electrode and electrolyte. Polymer solid electrolytes have good flexibility, processability, and contact interface properties, but low room temperature ionic conductivity, necessitating operation at elevated temperatures. Composite solid electrolytes (CSEs) are a promising alternative because they offer light weight and flexibility, like polymers, as well as the strength and stability of inorganic electrolytes. This paper presents a comprehensive review of recent advances in CSEs to help researchers optimize CSE composition and interactions for practical applications. It covers the development history of solid-state electrolytes, CSE properties with respect to nanofillers, morphology, and polymer types, and also discusses the lithium-ion transport mechanism of the composite electrolyte, and the methods of engineering interfaces with the positive and negative electrodes. Overall, the paper aims to provide an outlook on the potential applications of CSEs in solid-state lithium batteries, and to inspire further research aimed at the development of more systematic optimization strategies for CSEs.

Direct Measurements of Ionic Transport Behavior of Dual-Layer Porous Electrodes

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.

Efficient Lithium/Sodium-Ion Storage by Core-Shell Carbon Nanospheres@TiO2 Decorate by Epitaxial WSe2 Nanosheets Derived from Bimetallic Polydopamine Composites.

Metal-polydopamine coordination chemistry attracts great attention owing to the synergistic effect of adjustable components and advantageous structures. However, few efforts have been devoted to exploring bimetal-polydopamine composites, especially for multistructural composites with high-capacity components and high stability. In this regard, the TiO2 @C-WSe2 core-shell nanospheres are designed and fabricated based on Ti-W-polydopamine composites after selenization, in which the TiO2 nanoparticles are encapsulated or embedded in the carbon nanospheres and the external WSe2 nanosheets are grown epitaxially on the carbon surfaces, featuring multiple channels for ion diffusion and abundant active edges for electrochemical reactions. The introduction of WSe2 not only greatly improves the capacity but also results in exponential growth of the active edge. As a result, the as-prepared TiO2 @C-WSe2 displayed long-term cycling performance in lithium-ion batteries. Furthermore, the anode is assembled into sodium-ion batteries, manifesting a stable capacity of 352mA h g-1 at 1.0 A g-1 even after 2000 cycles, one of the best performances for polydopamine-based composites. Enhanced performance can be attributed to the synergies of high-capacity components and different dimensional materials. This work highlights that the rational design of functional structures provides a novel inspiration for electrodes with effective nanoarchitectures.

Solution-Processable Redox-Active Polymers of Intrinsic Microporosity for Electrochemical Energy Storage.

Redox-active organic materials have emerged as promising alternatives to conventional inorganic electrode materials in electrochemical devices for energy storage. However, the deployment of redox-active organic materials in practical lithium-ion battery devices is hindered by their undesired solubility in electrolyte solvents, sluggish charge transfer and mass transport, as well as processing complexity. Here, we report a new molecular engineering approach to prepare redox-active polymers of intrinsic microporosity (PIMs) that possess an open network of subnanometer pores and abundant accessible carbonyl-based redox sites for fast lithium-ion transport and storage. Redox-active PIMs can be solution-processed into thin films and polymer–carbon composites with a homogeneously dispersed microstructure while remaining insoluble in electrolyte solvents. Solution-processed redox-active PIM electrodes demonstrate improved cycling performance in lithium-ion batteries with no apparent capacity decay. Redox-active PIMs with combined properties of intrinsic microporosity, reversible redox activity, and solution processability may have broad utility in a variety of electrochemical devices for energy storage, sensors, and electronic applications.

Plasma-induced amorphous N-nano carbon shell for improving structural stability of LiNi0.8Co0.1Mn0.1O2 cathode

LiNi0.8Co0.1Mn0.1O2 (NCM) materials, which have a high specific capacity and low cost, suffer from large capacity attenuation and poor cycling performance in lithium-ion batteries. It is a straightforward and efficient strategy to elevate cyclic stability by building a stable surface coating to act as a valid physical or chemical barrier. In this study, N-doped carbon-coated active material NCM-N2 was successfully prepared by plasma-enhanced chemical vapor deposition (PECVD) in the N2 atmosphere. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical methods were used to study composition, structure, surface properties, and electrochemical properties. The coated NCM-N2 maintained good cycling performance (210.2 mAh g–1 at 0.1 C after 40 cycles, 188.5 mAh g–1 at 1 C after 100 cycles) and rate ability (131.7 mAh g–1 at 5 C rate). In comparison, the uncoated (NCM) electrode retained only 56.60% of its capacity (102.5 mAh g–1 at 1C after 100 cycles). The plasma-induced amorphous N-nano carbon shell on the surface of NCM effectively isolated the electrode from the electrolyte vastly inhibiting the occurrence of side reactions and was beneficial to the improvement of electronic conductivity. The plasma-induced amorphous N-nano carbon shell has great potential for enhancing the structural stability of Ni-rich ternary cathode materials, with broad application prospects in the Lithium-ion battery industry.

Revealing the cathode electrolyte interphase on Li- and Mn-rich materials by in-situ electrochemical atomic force microscopy

Solid electrolyte interphase (SEI) grown on electrode surfaces during charge-discharge processes plays a key role in the cycle performance of lithium-ion batteries. In-situ study of cathode electrolyte interphase (CEI) is challenging due to the complicated interfacial reactions on the cathode materials including gas formation and the formation of thin CEI film. Herein, we applied the electrochemical atomic force microscope (EC-AFM) to study the interfacial changes in high energy density Li- and Mn-rich (LMR) materials with an F-rich electrolyte (1 M LiPF6 FEC/FEMC/HFE). The study indicated that the electrolyte formed a uniform and dense passivation CEI film on the LMR material surface at high voltage. The CEI is composed of inorganic LiF substrate as confirmed by X-ray photoelectron spectroscopy (XPS). The assembled battery (LMR||Li) shows an excellent cycle performance and maintains capacity at 85.5% after 100 cycles, compared to the 13.7% retention rate of commercial carbonate electrolyte (1 M LiPF6 EC/EMC/DMC).

Hydrothermal synthesis of Mg-doped LiMn2O4 spinel cathode materials with high cycling performance for lithium-ion batteries

Hydrothermal synthesis of Mg-doped LiMn2O4 spinel cathode materials with high cycling performance for lithium-ion batteries

Boosting safety and performance of lithium-ion battery enabled by cooperation of thermotolerant fire-retardant composite membrane and nonflammable electrolyte

• Thermotolerant and fire-retardant nano-CaCO 3 -based membrane was designed. • LIBs with nonflammable electrolyte-immersed membrane possess superior cyclability. • LIBs exhibit better safety by preventing short circuit and reducing heat release. • Lithium ion full battery shows good long cycling stability at 120 °C under 2C. Developing nonflammable electrolytes is regarded as a convenient strategy to solve the combustion problem of lithium-ion batteries (LIBs), but its influences are limited by the severe shrinkage and high combustibility of polyolefin separators at elevated temperatures. Herein, an intrinsically thermotolerant and fire-resistant nano-CaCO 3 -based composite membrane (CPVH) is designed rationally. The CPVH membrane presents superior thermal stability (barely visible shrinkage at 300 °C), excellent nonflammability and extremely low heat release (∼11% as much as PP). Moreover, the alkaline nano-CaCO 3 can neutralize hydrofluoric acid that inevitably exists in LiPF 6 -based electrolytes, guaranteeing the long-term stability of interfacial layers. Noticeably, LiFePO 4 /Li battery with CPVH membrane delivered a discharge capacity of 133.6 mAh g −1 at 0.5C, along with a capacity retention of 93.0% and a coulombic efficiency of 99.9% after 650 cycles. Additionally, harsh safety tests of the battery demonstrate stable circuit safety at a high temperature of 150 °C and a significantly low heat release during thermal runaway. Significantly, the LiFePO 4 /CPVH/graphite full battery showed good cycling stability with a capacity retention of 78.4% and an average coulombic efficiency of 98.0% at 120 °C and 2C after 100 cycles. By combining CPVH composite membrane and nonflammable electrolyte, both safety and cycling performance of LIBs were improved completely.

Realizing ultrahigh-voltage performance of single-crystalline LiNi0.55Co0.15Mn0.3O2 cathode materials by simultaneous Zr-doping and B2O3-coating

Improving the high-voltage stability of cathode materials is a new strategy to enhance the energy density of lithium-ion batteries (LIBs) in recent years. However, as a traditional cathode material, the low reversible capacity at high cut-off voltages (≥ 4.3 V) greatly restricts the application of LiCoO2. Herein, we have rationally synthesized a novel single-crystalline LiNi0.55Co0.15Mn0.3O2 cathode material (Z-NCM@B) by using the synergistic effect of Zr-doping and B2O3-coating. Excitedly, the modified Z-NCM@B cathode material shows improved high-voltage stability and excellent long-term cycling performance. Furthermore, it is revealed that the stronger ZrO bond formed by Zr4+ dopant can stabilize the crystal structure and promote the migration of Li+ in the cathode materials. Meanwhile, the uniform B2O3 coating layer effectively suppresses the material corrosion by electrolyte and reduces the loss of transition metal ions during the charge/discharge cycle process. As anticipated, the Z2-NCM@B2 || graphite pouch-type full cell exhibits an advanced capacity retention of 96.9% over 250 cycles at an operating voltage of 4.2 V, while the capacity retention of the pristine NCM is only 88%. Besides, the Z2-NCM@B2 coin-cell retains a discharge capacity of 145.2 mA h g−1 at 1 C with a satisfactory capacity retention of 79.2% after 100 cycles within a broad voltage range between 2.95 and 4.7 V, which is much superior than that for the pristine NCM (130.9 mA h g−1, 70.9%). This synergistic modification strategy offers a reference for the practical application of NCM cathode materials with high-voltage stability and long-term cycling performance in LIBs.

Ceramic-Coated Separator to Enhance Cycling Performance of Lithium-ion Batteries at High Current Density

Given the global demand for green energy, the battery industry is positioned to be an important future technology. Lithium-ion batteries (LIBs), which are the most widely used battery in the market, are the focus of various research and development efforts, from materials to systems, that seek to improve their performance. The separator is one of the core materials in LIBs and is a significant factor in the lifespan of high-performance batteries. To improve the performance of present LIBs, electrochemical testing and related surface analyses of the separator is essential. In this paper, we prepared a ceramic (Boehmite, γ-AlOOH) coated polypropylene separator and a porous polyimide separator to compare their electrochemical properties with a commercialized polypropylene (PP) separator. The prepared separators were assembled into nickelmanganese-cobalt (NMC) cathode half-cell and full-cell lithium-ion batteries. Their cycling performances were evaluated using differential capacity and electrochemical impedance spectroscopy with ethylene carbonate:dimethylcarbonate (EC:DMC) electrolyte. The ceramic coated polypropylene separator exhibited the best cycle performance at a high 5 C rate, with high ionic conductivity and less resistive solid electrolyte interphase. Also, it was confirmed that a separator solid electrolyte interface (SSEI) layer formed on the separator with cycle repetition, and it was also confirmed that this phenomenon determined the cycle life of the battery depending on the electrolyte.

Fabrication of GeS-graphene composites for electrode materials in lithium-ion batteries

The new electrode materials are critically important for the development of lithium-ion batteries (LIBs). Herein, we report the synthesis of Germanium sulfide -graphene composite (GeS-G) by facile sonication which exhibits the excellent cycling performance for lithium-ion batteries. Under the condition of charge-discharge rate of 50 mA·g−1 and voltage window of 0.005–3 V, the specific capacity of GeS-G is 170 mAh·g−1 after 100 cycles, which is significantly higher than that of pure GeS. The results of the present work imply that the nanostructure of GeS-G is the potential electrode materials for application in high-performance lithium-ion batteries and enrich the gene bank of lithium-ion battery materials.

Interface-Stabilized Layered Lithium Ni-Rich Oxide Cathode via Surface Functionalization with Titanium Silicate.

Nickel-rich lithium metal oxide cathode materials have recently be en highlighted as next-generation cathodes for lithium-ion batteries. Nevertheless, their relatively high surface reactivity must be controlled, as fading of the cycling retention occurs rapidly in the cells. This paper proposes functionalized nickel-rich lithium metal oxide cathode materials by a multipurpose nanosized inorganic material-titanium silicon oxide-via a simple thermal treatment process. We examined the topologies of the nano-titanium silicate-functionalized nickel-rich lithium metal oxide cathodes with scanning electron microscopy and quantitatively analyzed their improved mechanical properties using microindentation. The cell containing nickel-rich lithium metal oxide cathodes suffered from poor cycling behavior as the electrolytes persistently decomposed; however, this behavior was effectively inhibited in the cell by nano-titanium silicate-functionalized nickel-rich lithium metal oxide cathodes. Further ex situ analyses indicated that the particle hardness of the nano-titanium silicate-functionalized nickel-rich lithium metal oxide cathode materials was maintained, and decomposition of the electrolyte by the dissolution of transition metals was thoroughly inhibited even after 100 cycles. Based on these results, we concluded that the use of nano-titanium silicate as a coating material for nickel-rich lithium metal oxide cathode materials is an effective way to enhance the cycling performance of lithium-ion batteries.