电动汽车与锂离子电池

文章简要介绍了混合动力汽车、插电式混合动力汽车、纯电动汽车和锂离子动力电池及其关键材料。发展电动汽车可以大幅度降低人们对石油的依赖和改善城市空气质量。锂离子电池性能优越,为电动汽车的发展提供了支撑。近期,新一代锂离子动力电池正极材料即将走向应用,可使电动汽车里程增加一倍,材料选择和电池设计及制造工艺与电池储存能量、寿命、安全等密切相关, 尊道而重德,可做出“好”电池。     

锂离子电池中的物理问题

锂离子电池是一种性能优越的新型可充放电池．文章在简述了它的原理和特性之后，着重介绍了所涉及的一些物理问题，诸如嵌入物理、载流子输运、渗流、分形和相变等，以期对锂离子电池有更深入的理解     

大功率锂离子电池储能电源系统的研制与应用

采用高功率高安全性的磷酸铁锂电芯作为储能元件,研制了一种在车载平台中应用的大功率储能电源。在储能电源中配置了高性能的电池采样和主动均衡模块,以及充放电管理系统,可以有效地提高系统可靠性和使用寿命。研制过程中,大功率储能电源进行了大量的工程化试验考核,包括运输安全性、环境适应性、维修性和任务可靠性等工程化指标。最后,21台储能电源在超过55 ℃的高温地区考核超过12个月,储能电源系统的可靠性得到验证。     

锂离子电池中的物理问题及其研究进展

锂离子电池作为一种性能优越的新型可充放电池已经或将要在移动通信、手提式计算机和电动汽车等诸多领域获得广泛的应用 .然而与锂离子电池相关的物理问题却往往被人们忽视 .例如 ,如何从本质上来提高正极材料的体相电子电导率 ,而不是在正极活性物质中添加炭黑之类的电子导电材料 .文章将着重针对与锂离子电池相关的物理问题 ,介绍近年来的主要进展 ,以期待对锂离子电池有更深入的了解 .     

纳米储锂材料和锂离子电池

简单综述了锂离子电池的基本原理和发展现状,对中国科学院物理研究所固体离子学课题组在纳米储锂材料方面的研究进展做了介绍.用HRTEM等手段研究了纳米SnO、纳米Si以及纳米SnSb合金在Li入脱嵌过程中结构的变化.着重介绍了一种具有纳米微孔的球形硬碳材料和纳米SnSb合金钉扎的复合负极材料,在高功率密度和高能量密度锂离子电池方面具有广阔应用前景.     

纳米储锂材料和锂离子电池

简单综述了锂离子电池的基本原理和发展现状，对中国科学院物理研究所固体离子学课题组在纳米储锂材料方面的研究进展做了介绍。用HRTEM等手段研究了纳米SnO、纳米Si以及纳米SnSb合金在Li入脱嵌过程中结构的变化。着重介绍了一种具有纳米微孔的球形硬碳材料和纳米SnSb合金钉扎的复合负极材料，在高功率密度和高能量密度锂离子电池方面具有广阔应用前景。     

以碳粉为负极材料制备锂离子电池及电池性能测试

在能量存储技术中,锂离子电池是高能量密度的电化学电源.以碳为负极材料,涂膜制备了负极片,以锂片为正极片制备了CR2016锂离子电池,并对其性能进行了测试,分析了碳粉为锂电负极材料的特性.     

锂离子电池正极材料LiMnPO4研究进展

综述了新型锂离子电池正极材料LiMnPO4的研究进展,重点对该材料的结构、结构与电化学性能的关系、阳离子掺杂对材料性能的影响、多种合成方法和材料改性措施进行了较详细的评述,并对该材料的应用前景进行了展望.     

基于遗传算法的锂离子电池等效电路参数识别

结合锂离子电池双极性等效电路模型提出了一种基于遗传算法的参数识别方法,该方法通过指数函数对电路模型中的电阻、电容、恒压源等元件进行有理逼近,根据电池在不同充放电速率下的输出电压特性数据,通过实数编码遗传算法得到最优的函数参数,从而得到最优的电阻、电容,开路电压等电路参数值,针对电池在不同的工作状态,不同的工作参数下的运行数据,系列仿真和实验结果表明该算法原理简明,收敛较快,辨识得到的最优模型其电压输出特性与电池的实际电压输出特性基本吻合,能较精确的反映电池的实际特性,具有较高的辨识精度。     

基于电池热特性及产热行为的新型锂离子电池评价

建立了一种新的基于锂离子电池热特性及产热行为的电池性能评价方法. 通过测量一系列不同容量及电极材料的18650电池在不同充放电时间及电流下其充放电能量的变化,建立了一个包含焦耳热与极化热影响因子的表达电池在充放电过程中的能量损失的模型. 利用这种模型,计算出电池总内阻R以及极化参数′,并且对R及′在不同温度下的变化情况进行了研究,建立一个对不同电池和不同温度都适用的普适性模型.     

Conductivity and applications of Li-biphenyl-1,2-dimethoxyethane solution for lithium ion batteries

The total conductivity of Li-biphenyl-1,2-dimethoxyethane solution(Li_xBp(DME)_(9.65), Bp = biphenyl, DME = 1,2-dimethoxyethane, x = 0.25, 0.50, 1.00, 1.50, 2.00) is measured by impedance spectroscopy at a temperature range from 0℃ to 40℃. The Li_(1.50)Bp(DME)_(9.65) has the highest total conductivity 10.7 m S/cm. The conductivity obeys Arrhenius law with the activation energy(E_(a(x=0.50))= 0.014 eV, E_(a(x=1.00))= 0.046 eV). The ionic conductivity and electronic conductivity of Li_xBp(DME)_(9.65) solutions are investigated at 20℃ using the isothermal transient ionic current(ITIC) technique with an ion-blocking stainless steal electrode. The ionic conductivity and electronic conductivity of Li_(1.00)Bp(DME)_(9.65) are measured as 4.5 mS/cm and 6.6 mS/cm, respectively. The Li_(1.00)Bp(DME)_(9.65) solution is tested as an anode material of half liquid lithium ion battery due to the coexistence of electronic conductivity and ionic conductivity. The lithium iron phosphate(LFP) and Li_(1.5)Al_(0.5)Ti_(1.5)(PO_4)_3(LATP) are chosen to be the counter electrode and electrolyte, respectively. The assembled cell is cycled in the voltage range of 2.2 V-3.75 V at a current density of 50 mA/g. The potential of Li_(1.00)Bp(DME)_(9.65) solution is about 0.3 V vs. Li~+/Li, which indicates the solution has a strong reducibility. The Li_(1.00)Bp(DME)_(9.65) solution is also used to prelithiate the anode material with low first efficiency, such as hard carbon, soft carbon and silicon.     

锂离子电池Sn-Al薄膜电极的制备及电化学性能研究

采用磁控溅射沉积技术制备了纳米级Sn-Al合金薄膜电极材料,并用X射线衍射和扫描电子显微镜进行表征,用高精度电池测试系统进行充放电和循环伏安测试.结果表明直流DC与射频RF两种不同的溅射方法制备的Sn-Al薄膜电极具有很大的性能差异,前者DC法制备的材料颗粒细小,表现出稳定的循环性能,其首次放电容量为1060 mAh/g,首次效率为71.7％,电极经过50次循环后比容量保持在700 mAh/g以上.后者RF法制备的材料颗粒较大,放电比容量开始上升,第五次循环后接着逐渐衰减,表现出较差的循环性能. 关键词： 锂离子电池 磁控溅射 Sn-Al合金 电化学性能     

锂离子电池多尺度数值模型的应用现状及发展前景

锂离子电池是一种较为复杂的电化学系统, 其涵盖质量传递、电荷传递、热量传递以及多种电化学反应等物理化学过程. 其不仅物理尺度跨越大, 从微观活性颗粒、极片、电芯跨越到电池模组, 还面临着成组配对以及均衡性的问题, 这些问题加剧了电池设计和性能综合评估的难度. 通过计算机数值仿真技术, 建立数学模型, 全面和系统地捕捉电池工作过程各物理场的相互作用机理, 分析其演化规律, 能够为优化电池系统设计提供理论支撑. 本文对锂离子电池的数值模型研究进展和发展趋势进行了综述. 同时对主要理论模型进行了分类整理, 总结了它们的特点、适用范围和局限性, 指出了将来进一步研究的方向和难点所在, 这些对锂离子电池多尺度数值模型的理论研究和工程应用都具有指导性的意义.     

Applications of carbon nanotubes in high performance lithium ion batteries

The development of lit;triton ion batteries （LIBs） relies on the improvement in the performance of electrode materials with higher capacity, higher rate capability, and longer cycle lift;. In this review article, the recent advances in carbon nanotube （CNT） anodes, CNT-based composite electrodes, and CNT current collectors for high performance LIBs are concerned. CNT has received considerable attentions as a candidate material for the LIB applications. In addition to a possible choice for anode, CNT has been recognized as a solution in improving the performance of the state-of-the-art electrode materials. The CNT-based composite electrodes can be fabricated by mechanical or chem- ical approaches. Owing to the large aspect ratio and the high electrical conductivity, CNTs at very low loading can lead to an efficient conductive network. The excellent mechanical strength suggests the great potential in forming a structure scaffold to accommodate nano-sized electrode materials. Accordingly, the incorporation of CNTs will enhance the conductivity of the composite electrodes, mitigatc the agglomeration problem, decrease the dependence on inactive binders, and improve the clcctrochenfical properties of both anode and cathode materials remarkably. Freestanding CNT network can be used as lightweight current collectors to increase the overall energy density of LIBs. Finally, research perspectives for exploiting CNTs in high-performance LIBs are discussed.     

Size effects in lithium ion batteries

Size-related properties of novel lithium battery materials, arising from kinetics, thermodynamics, and newly discovered lithium storage mechanisms, are reviewed. Complementary experimental and computational investigations of the use of the size effects to modify electrodes and electrolytes for lithium ion batteries are enumerated and discussed together.Size differences in the materials in lithium ion batteries lead to a variety of exciting phenomena. Smaller-particle materials with highly connective interfaces and reduced diffusion paths exhibit higher rate performance than the corresponding bulk materials. The thermodynamics is also changed by the higher surface energy of smaller particles, affecting, for example,secondary surface reactions, lattice parameter, voltage, and the phase transformation mechanism. Newly discovered lithium storage mechanisms that result in superior storage capacity are also briefly highlighted.     

锂离子电池电极材料的第一性原理研究进展

文章综述了第一性原理计算在锂离子电池电极材料模拟与设计方面的研究进展.电极材料的研究包括电极材料的电子结构和电子导电性的研究,嵌锂电位、锂离子输运特性、嵌锂过程中局部结构弛豫与相变以及材料表面特性研究等方面,第一性原理计算在上述诸方面的研究都取得了一定的进展.这些理论上的研究成果,可以帮助人们加深对材料性能与机理的理解,同时对材料的设计也具有指导意义.     

Effects of binder content on manganese dissolution and electrochemical performances of spinel lithium manganese oxide cathodes for lithium ion batteries

In this study, the effects of the polyvinylidene fluoride (PVdF) binder on the Mn dissolution behavior and electrochemical performances of LiMn₂O₄ (LMO) electrodes are investigated. It is found that increasing the PVdF content (3, 5, 7, and 10 wt.%) leads to reduced Mn dissolution, and thus superior cycle performance at elevated temperature (60 °C). This can be ascribed to increased binder coverage on the LMO surface, as evidenced by X-ray photoelectron spectroscopy measurements, which acts a role as a passivation layer for Mn dissolution. The rate capability of the LMO electrode is hardly deteriorated as the PVdF content increases, despite the increasing surface coverage. Electrochemical impedance measurements reveal that the LMO electrode with higher binder loading exhibits lower electrode impedance, which is suggested to be due to enhanced electronic passage through the composite LMO electrode.     

Brief overview of electrochemical potential in lithium ion batteries

The physical fundamentals and influences upon electrode materials' open-circuit voltage(OCV) and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries(LIBs), and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.     

锂离子电池SnSb/MCMB核壳结构负极材料嵌锂性能研究

以酸处理的中间相碳微球(MCMB)为载体, 用化学还原法在碳球表面沉积SnSb合金, 合成SnSb 包覆碳球的核壳结构负极材料. 采用XRD, SEM技术对材料的结构和形貌进行了表征, 用恒电流充放电(CC)、循环伏安(CV)和交流阻抗(EIS)测试了材料的电化学性能. 实验结果表明: SnSb/MCMB样品呈现纳米晶与非晶态的混合组织; 单一SnSb合金的容量衰减较快, 而对于SnSb/MCMB复合材料, 细小的合金颗粒均匀钉扎在MCMB表面, 不仅改善了颗粒的团聚现象, 而且增强了材料的导电能力, 使材料的循环稳定性得到改善, 复合材料具有936.161 mAh/g的首次放电比容量, 首次库仑效率80.3%, 50次循环后容量维持在498.221 mAh/g. 关键词： SnSb合金 锂离子电池 中间相碳微球(MCMB) 电化学性能