Empowering the Future: Exploring the Construction and Characteristics of Lithium-Ion Batteries

Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li . Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO4, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.

In-situ design and construction of lithium-ion battery electrodes on metal substrates with enhanced performances：A brief review

For the ever-growing demand of advanced lithium-ion batteries, it is highly desirable to grow self-supported micro-/nanostructured arrays on metal substrates as electrodes directly. The in-situ growth of electrode materials on the conducting substrates greatly simplifies the electrode fabrication process without using any binders or conductive additives. Moreover, the well-ordered arrays closely connected to the current collectors can provide direct electron transport pathways and enhanced accommodation of strains arisen from lithium ion lithiation/delithiation. This article summarizes our recent work on design and construction of lithium-ion battery electrodes on metal substrates. An aqueous solution-based process and a microemulsion-mediated process have been respectively presented to control the kinetic and thermodynamic processes for the micro-/nanostructured array growth on metal substrates, with particular attention to CuO nanorod arrays and microcog arrays successfully prepared on Cu foil substrates. They can be directly used as binder-free electrodes to build advanced lithium-ion batteries with high energy, high safety and high stability.

Two-Dimensional Lithium-Ion Battery Modeling with Electrolyte and Cathode Extensions

A two-dimensional model for transport and the coupled electric field is applied to simulate a charging lithium-ion cell and investigate the effects of lithium concentration gradients within electrodes on cell performance. The lithium concentration gradients within electrodes are affected by the cell geometry. Two different geometries are investigated: extending the length of the electrolyte past the edges of the electrodes and extending the length of the cathode past the edge of the anode. It is found that the electrolyte extension has little impact on the behavior of the electrodes, although it does increase the effective conductivity of the electrolyte in the edge region. However, the extension of the cathode past the edge of the anode, and the possibility for electrochemical reactions on the flooded electrode edges, are both found to impact the concentration gradients of lithium in electrodes and the current distribution within the electrolyte during charging. It is found that concentration gradients of lithium within electrodes may have stronger impacts on electrolytic current distributions, depending on the level of completeness of cell charge. This is because very different gradients of electric potential are expected from similar electrode gradients of lithium concentrations at different levels of cell charge, especially for the LixC6 cathode investigated in this study. This leads to the prediction of significant electric potential gradients along the electrolyte length during early cell charging, and a reduced risk of lithium deposition on the cathode edge during later cell charging, as seen experimentally by others.

基于固态电解质膜的软包电池制备与初步表征

固态电池安全性高、可适应高比能正负极,是蓄电池发展的方向,但存在固相界面阻抗大、界面结构稳定性差等问题。为了快速评估固态电池技术在实用型蓄电池中的作用,本文采用流延法制备了在50℃下离子电导率为6.16×10^(-4)S/cm的固态电解质膜。以高镍三元为正极、石墨为负极,制备了质量为1.1214 g、容量为53.44 mAh的微型软包电池和容量为7252.8 mAh的大容量软包电池。微型软包电池实现了5 C高倍率的放电和150次循环,大容量软包电池在放电深度(DOD)为13.78%时,实现了439次循环充放电。以上结果说明固态电解质膜满足在锂离子电池中使用的要求,然而这些电池的界面构筑仍有不足之处。基于本文结果,通过对固态电解质膜材料、电池化成制度等进行改进,有望促进高性能电池的研发。

磷酸铁锂锂离子电池电芯注液量相关试验验证与探讨

通过详细的理论计算,推导出LFP/230 Ah锂离子电池电芯孔隙率和极限饱和吸液量,并且通过试验设计进行验证。通过调整LFP/230 Ah锂离子电池电芯的一次注液量与不同高温下的静置时间来验证随后高温负压化成后电芯各项电性能参数受到的影响。测试及验证结果表明:随着一次注液后高温静置时间的延长,LFP/230 Ah锂离子电池电芯中游离态电解液量逐渐减少,而且在24 h后基本达到稳定状态;一次注液后随着高温静置时间的延长,电芯在化成过程中的温度逐渐降低,而且化成结束后的开路电压越来越高,分容容量有升高趋势,DCR有降低趋势,电芯满充后黑斑析锂位置点的数量减少,而且黑斑面积也逐渐缩小,但在SoC为0.6%下的K值筛选没有受到显著影响。

镍钴锰三元锂离子电池不同电压下浮充失效机理及热安全研究

三元锂离子电池由于优异的电化学性能在储能领域得到广泛应用。本研究采用商用18650型镍钴锰酸锂/石墨体系电池作为实验对象,分别在4.2 V、4.4 V和4.6 V的电压下进行浮充实验。通过对新鲜电池及不同电压工况下浮充电池的容量测试、容量增量分析、阻抗测试以及拆解电池后电极材料的XRD、XPS和SEM表征,研究NCM电池浮充失效机理;通过新鲜电池及不同电压工况下浮充失效电池的ARC测试,研究浮充对NCM电池热安全性影响。实验结果表明,浮充电压越高,电池老化速度越快,4.6 V浮充下电池的平均容量衰减速率达1.166%/d。高电压浮充加剧了电池内部电解液与电极之间的界面反应,导致SEI膜增厚,阻抗增加;高电压浮充也导致了正极集流体的腐蚀,使得Al析出并沉积到负极,造成电池容量进一步衰减;浮充后电池自加热起始温度(T_(onset))明显降低,电池热安全性降低。本工作基于NCM电池浮充过程分析、浮充失效材料表征及热失控实验研究,将为了解浮充对锂离子电池的性能和热安全性影响提供理论依据和技术指导。

中型AUV锂离子电池系统设计研究

中型AUV具有续航力强、载荷量大等优势,在长航程科学观测、大载荷搭载等任务领域有较好的应用前景。本文根据某中型AUV的任务需求和指标进行锂离子电池系统设计,基于21700圆柱电芯,对电池成组方案、焊接工艺、电路设计和BMS设计等进行研究,并进行了相关性能测试和分析。试验结果表明,21700圆柱电池在中型AUV锂离子电池系统中具有较好的适用性。

Lignin in storage and renewable energy applications： A review

Lignin is a cheap, abundant and non-toxic group of complex phenolic polymers obtained in large amounts from the papermaking and cellulosic biofuel industries. Although the application of lignin has been ex- plored in these and several more industries, there are limited applications of lignin in the energy industry. However, numerous research revealed a great interest in the exploration of this renewable biopolymer in storage energy devices. Some of these applications include the use of lignin as an expander for lead-acid batteries, electrodes for primary and rechargeable batteries, electrodes for electronic double layer capac- itors and electrochemical pseudocapacitors, and to feed different types of fuel cells. The use of lignin in energy storage devices improves not only the performance of these devices but also decreases the price and toxicity, contributing to obtaining greener energy devices. Based on the above, this review provides an overview of the main research work related to the use of lignin as a renewable component, suitable to replace some synthetic and toxic compounds used in the fabrication of energy storage devices with particular emphasis on batteries, advanced supercapacitors, and solar and fuel cells.

Process engineering in electrochemical energy devices innovation

This review focuses on the application of process engineering in electrochemical energy conversion and storage devices innovation. For polymer electrolyte based devices, it highlights that a strategic simple switch from proton exchange membranes(PEMs) to hydroxide exchange membranes(HEMs) may lead to a new-generation of affordable electrochemical energy devices including fuel cells, electrolyzers, and solar hydrogen generators. For lithium-ion batteries, a series of advancements in design and chemistry are required for electric vehicle and energy storage applications. Manufacturing process development and optimization of the LiF eP O_4/C cathode materials and several emerging novel anode materials are also discussed using the authors' work as examples.Design and manufacturing process of lithium-ion battery electrodes are introduced in detail, and modeling and optimization of large-scale lithium-ion batteries are also presented. Electrochemical energy materials and device innovations can be further prompted by better understanding of the fundamental transport phenomena involved in unit operations.

动力电池常见故障模拟实验教学平台开发

动力电池是电动汽车的能量来源。锂电池因其高能量密度、高功率密度和长寿命而成为电动汽车的主流储能系统,然而锂电池系统的各种故障也对电池的性能和安全性构成了威胁,因此开发了一款动力电池常见故障模拟的教学实验平台。该平台包括恒温箱、测试系统、上位机和数据分析等软件,能够仿真出不同类型的电池模组故障数据,包括容量故障、阻值异常故障、短路故障等,可探究不同故障对车用锂电池的影响,为电池故障诊断算法提供了有效的数据支持。同时,该平台能够促进学生发挥主观能动性,提升学生应用基本理论知识解决工程实际问题的能力。

Effects of temperature variation on Li_xFe PO_4/C(0

Li Fe PO4/C was prepared via solid state reaction and characterized with X-ray powder diffraction and charge–discharge test. As-prepared Li Fe PO4/C has a triphylite structure and exhibits an excellent rate capability and capacity retention. Electrochemical impedance spectroscopy(EIS) was applied to investigate LixFe PO4/C(0<x<1) electrode on temperature variation. The valid equivalent circuit for EIS fitting was determined which contains an intercalation capacitance for Li+ ion accumulation and consumption in the electrode reaction. The surface layer impedance needs to be included in the equivalent circuit when Li Fe PO4/C is deeply delithiated at a relatively high temperature. EIS examination indicates that a temperature rise leads to a better reversibility, lower charge transfer resistance, higher exchange current density J0 and greater Li+ ion diffusion coefficient for the LixFe PO4/C electrode process. The Li+ ion concentration in LixFe PO4/C is potential to impact the Li+ ion diffusion coefficient, and a decrease in the former results in an increase in the latter.

Materials Research Advances towards High-Capacity Battery/Fuel Cell Devices(Invited paper)

The world has entered an era featured with fast transportations,instant communications,and prompt technological revolutions,the further advancement of which all relies fundamentally,yet,on the development of cost-effective energy resources allowing for durable and high-rate energy supply.Current battery and fuel cell systems are challenged by a few issues characterized either by insufficient energy capacity or by operation instability and,thus,are not ideal for such highly-demanded applications as electrical vehicles and portable electronic devices.In this mini-review,we present,from materials perspectives,a few selected important breakthroughs in energy resources employed in these applications.Prospectives are then given to look towards future research activities for seeking viable materials solutions for addressing the capacity,durability,and cost shortcomings associated with current battery/fuel cell devices.

Comparison between SiC- and Si-Based Inverters for Photovoltaic Power Generation Systems

100-W class power storage systems were developed, which comprised spherical Si solar cells, a maximum power point tracking charge control-ler, a lithium-ion battery, and one of two different types of direct current (DC)-alter- nating current (AC) converters. One inverter used SiC met-al-oxide-semicon-ductor field-effect transistors (MOSFETs) as switching devices while the other used Si MOSFETs. In these 100-W class inverters, the ON resistance was considered to have little influence on the efficiency. Nevertheless, the SiC-based inverter exhibited an approximately 3% higher DC-AC conversion efficiency than the Si-based inverter. Power loss analysis indicated that the higher efficiency resulted predominantly from lower switching and reverse recovery losses in the SiC MOSFETs compared with in the Si MOSFETs.

锂离子电池比能量与针刺结果相关性探究

为了探究锂离子电池的比能量(体积比能量和质量比能量)与安全性的关联性,选取了45批次不同能量、重量或尺寸的锂离子单体电池进行了针刺试验。结果显示锂离子电池针刺试验结果的不通过率与其比能量呈现正相关关系,即比能量越大的锂离子单体电池,针刺不通过的概率越高,在高比能量区间甚至超过85%。同时对这种相关性内在的原因进行了分析,为锂离子电池的设计及使用提供了指导意义。

硅纳米管在新能源领域中的应用研究进展与展望

硅纳米管独特的物理和化学性质使其有望在新能源领域中有巨大的潜在作用,但关于其在新能源领域中的应用报道相对较少。本文综述了关于硅纳米管在锂离子电池、太阳能电池、规模储能及节约能源等方面的应用研究进展,详细介绍了孔隙、薄壁、涂层及壳层等对硅纳米管在锂离子电池应用中的影响,以及未来在热管理、燃料电池和柔性电池等新能源领域中应用的发展趋势,总结了其在应用和发展中亟待解决的主要问题,提出了可能解决这些问题的方法;以便对硅纳米管在未来的新能源领域应用和研究开发中有帮助。

锂金属电池电解液的研究进展

锂离子电池拥有高能量密度和长循环寿命等众多优点,在可移动电子设备、电动汽车和储能等领域得到越来越广泛的应用。锂金属因其最高的能量密度,被认为是负极的终极目标,因此成为研究的前沿热点。由于锂金属负极反应活性很高,传统电解液碳酸酯和其适配性很差,因此亟待开发锂金属电池电解液。本文主要阐述锂金属电池电解液的研究进展,介绍了锂金属电解液的常用表征方法,包括库伦效率测试,负极界面表征,不同类型电池测试等。并对锂金属电池电解液主要开发方向进行了介绍,包括全氟电解液、双盐电解液、高盐电解液、局域高盐电解液等,分析了其性能优劣。随着研究的成熟,未来的研究将基于更加商业化的体系开发电解液,并多方向融合发展,开发新型有机溶剂等。相信通过持续的深入研究和创新,锂金属电池商业化将成为现实。

表面积对功率型磷酸铁锂电芯性能的影响

纳米磷酸铁锂是商业化超高功率锂离子电芯的首选正极材料,比表面积对电性能有重要影响。考察了磷酸铁锂比表面积对电芯内阻、倍率和循环性能的影响。结果表明,磷酸铁锂正极材料的比表面积增大,相应电芯的电荷转移阻抗降低,倍率性能提高。高比表面积会增加与电解液的反应,从而对循环寿命有一定影响,对正极表面处理后可提升循环寿命,为大容量功率电芯设计提供依据。

基于视觉特征的动力电池组综合健康评估及分筛方法

随着电动汽车领域的快速发展,海量电池系统的健康监管和性能评估成为有待解决的关键技术之一。本工作搭建了电池组等效电路模型,依托单体不一致型参数的正交组合模拟多种电池组健康状态,通过模型仿真生成电池组样本数据集。搭建了卷积神经网络模型,以电池组局部充电电压曲线图像为输入,提取能够反映电池组健康状态的形态学特征,对电池组进行快速分类。选用整组可用容量、可用能量、容量利用率和能量利用率四个参数指标,通过层次分析法分配各参数权重,提出一种综合考虑电池组性能表征的健康度评价指标,依据评价指标实现电池组分筛。在仿真生成的数据集上对分类模型进行了训练和测试,结果表明,所构建的电池组分类模型在测试集上能够达到97%以上的准确率。通过分类任务混淆矩阵的一系列模型评价指标,进一步验证了该方法的有效性。本工作提出的基于视觉特征提取的电池组健康状态综合评估和分筛方法有助于推动对电池性能评估的研究,为电池系统的健康监管提供新的理论依据。

重卡辅助动力电池加热系统能耗对比及优化

清洁能源的重卡汽车因其零排放、长续航等特性近年来得到了迅速发展,其动力驱动配置多采用燃料电池为主动力电池为辅的形式。低温环境下,重卡辅助动力电池性能衰减不足以承担辅助动力源削峰填谷的重担。因此,加热辅助动力电池使其恢复充电放电性能对重卡汽车应对寒冷环境显得尤为重要。本工作以方形磷酸铁锂电池组为研究对象,通过实验测试单体磷酸铁锂电池−10℃、0℃、10℃、20℃的放电工况,得出电池的低温热特性,建立单体电池的热模型并验证其模型有效性。基于该模型提出了一种以石墨烯加热膜为主要热源,整车车载热源余热为辅助热源的加热升温系统。同时,为了降低该加热系统能耗,基于传热原理建立了电池加热系统线性时变模型预测控制器(MPC)。结果表明,重卡在C-WTVC的行驶工况下,电池加热系统通过换热器利用车载热源余热能够提升动力电池组升温速率,使用加热膜和换热器的加热系统比传统PTC加热系统能耗降低了30%。采用MPC控制策略的加热系统比PID控制的加热系统能耗降低了14%。