Rechargeable lithiated silicon-sulfur (SLS) battery prototypes

Amorphous columnar structured silicon film electrodes were prepared and electrochemically tested in dioxolane based electrolyte solution, containing LiNO₃. The electrochemical performance of prelithiated amorphous silicon anodes coupled with sulfur composite cathodes was evaluated in full Si-Li-Sulfur (SLS) cells. The reversible capacity at the first 10 cycles was 600 mAh/g sulfur with gradual fading to ~ 380 mAh/g sulfur after 60 cycles which is the highest obtained capacity reported for SLS full cells. Possible reasons for this capacity fading are discussed.     

Design and Construction of 3D Porous Na3V2(PO4)3/C as High Performance Cathode for Sodium Ion Batteries

An easy and delicate approach using cheap carbon source as conductive materials to construct 3D sequential porous structural Na3V2(PO4)3/C(NVP/C)with high performance for cathode materials of sodium ion battery is highly desired.In this paper,the NVP/C with 3D sequential porous structure is constructed by a delicate approach named as“cooking porridge”including evaporation and calcination stages.Especially,during evaporation,the viscosity of NVP/C precursor is optimized by controlling the adding quantity of citric acid,thus leading to a 3D sequential porous structure with a high specific surface area.Furthermore,the NVP/C with a 3D sequential porous structure enables the electrolyte to interior easily,providing more active sites for redox reaction and shortening the diffusion path of electron and sodium ion.Therefore,benefited from its unique structure,as cathode material of sodium ion batteries,the 3D sequential porous structural NVP/C exhibits high specific capacities(115.7,88.9 and 74.4 mA·h/g at current rates of 1,20 and 50 C,respectively)and excellent cycling stability(107.5 and 80.4 mA·h/g are remained at a current density of 1 C after 500 cycles and at a current density of 20 C after 2200 cycles,respectively).     

聚二巯化合物正极材料的合成及性质的初步研究

固态电池发展至今，许多比能量高、贮存性能好的新型电池产品不断涌向市场，而目前广泛用于正极材料的大多数物质是层状化合物［１］，如聚乙炔，聚苯胺等化合物，它们贮存能量的方式主要是通过插入化学反应来实现，本工作将合成一种高分子材料——２．５－二巯基－１，３...     

Electrochemical lithium and sodium intercalation into TaFe1.25Te3

Lithium and sodium have been topotactically inserted in the lattice of TaFe_1.25Te₃ by electrochemical procedures. The existence of electronically unequivalent sites occupied by tellurium atoms conditions a two-step insertion process. In each step, the alkali metal ions occupy empty sites in the structure which are coordinated by tellurium atoms of a different set of sites. The␣thermodynamic and kinetic parameters of Li _x TaFe_1.25Te₃ and Na _x TaFe_1.25Te₃ have been determined and compared with other inserted binary and ternary chalcogenides. The values of the free energy of intercalation are less negative than those previously reported for TaTe₂ and close to those found for the misfit layer compound (PbS)_1.13TaS₂. The values of alkali metal ion diffusivity are closer to those reported for the binary telluride, due to the similarities in the atoms exposed to the interlayer space. Received: 14 October 1997 / Accepted: 14 November 1997     

锂离子二次电池碳负极材料的改性

作为锂离子二次电池的碳负极材料，其改性方面的研究内容主要有：引入非金属元素，引入金属元素，处理表面及其它方面。纺入的非金属元素有硼，硅，氮，磷和硫。引入的金属元素有钾，铝，镓和钒，镍，钴，铜，铁等过渡金属元素。表面处理的方法包括氧化，形成表面层等。     

锂离子电池用α-Fe2O3-Ag复合纳米棒负极材料的制备及储锂性能

采用FeOOH纳米棒为前驱体,通过层层自组装法及随后的热处理过程制备出α-Fe2O3-Ag复合纳米棒.采用透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)和电化学性能测试对样品的形貌、结构及电化学性能进行了表征.结果表明,Ag纳米颗粒均匀地分布在α-Fe2O3纳米棒的表面.作为锂离子电池负极材料,α-Fe2O3-Ag复合纳米棒表现出了较好的循环性能和较高的比容量.180个循环后,其比容量高达549.8 mA.h/g.     

Defect Engineering and Anisotropic Modulation of Ionic Transport in Perovskite Solid Electrolyte LixLa(1−x)/3NbO3

Solid electrolytes, such as perovskite Li_3xLa_2/1−xTiO₃, Li_xLa_(1−x)/3NbO₃ and garnet Li₇La₃Zr₂O₁₂ ceramic oxides, have attracted extensive attention in lithium-ion battery research due to their good chemical stability and the improvability of their ionic conductivity with great potential in solid electrolyte battery applications. These solid oxides eliminate safety issues and cycling instability, which are common challenges in the current commercial lithium-ion batteries based on organic liquid electrolytes. However, in practical applications, structural disorders such as point defects and grain boundaries play a dominating role in the ionic transport of these solid electrolytes, where defect engineering to tailor or improve the ionic conductive property is still seldom reported. Here, we demonstrate a defect engineering approach to alter the ionic conductive channels in Li_xLa_(1−x)/3NbO₃ (x = 0.1~0.13) electrolytes based on the rearrangements of La sites through a quenching process. The changes in the occupancy and interstitial defects of La ions lead to anisotropic modulation of ionic conductivity with the increase in quenching temperatures. Our trial in this work on the defect engineering of quenched electrolytes will offer opportunities to optimize ionic conductivity and benefit the solid electrolyte battery applications.     

Li-S电池硫正极性能衰减机理分析及研究现状概述

由于汽车工业的持续发展, 对高能量密度二次电池的需求逐步增加, 锂硫电池开始走进人们的视野. 锂硫电池的理论比能量高达2600 Wh/kg, 而单质硫的理论比容量达1680 mAh/g. 同时, 硫的储量丰富, 廉价, 并且环境友好. 虽然可充电锂硫电池相比于传统锂离子电池有诸多优势, 但目前其可实现的实际比容量远低于理论比容量, 循环寿命也较短等弊端限制了其大规模应用. 作者从Li-S电池正极的工作原理出发, 对硫正极容量损失及衰减机理做了深刻的解析, 并结合本实验室的工作归纳总结了导致硫正极容量衰减的主要因素. 针对硫正极容量衰减因素, 从碳导电结构、聚合物包覆以及纳米金属氧化物添加剂等方面, 对近年来提高硫正极性能的主要研究方向及最新研究进展进行了综述, 并对其中存在的问题进行分析, 最后对提高Li-S电池的整体性能提出展望.     

石墨烯包覆碳纳米管-硫(CNT-S)复合材料及锂硫电池性能

针对锂硫电池研究与实际应用中遇到的主要问题, 本文通过一种简单有效的水热法还原氧化石墨烯对商用碳纳米管-硫(CNT-S)纳米复合材料进行包覆, 形成一种可有效抑制多硫聚合物扩散的石墨烯包覆结构。X射线衍射(XRD), 扫描电子显微镜(SEM)表征结果表明硫均匀地负载在碳纳米管上, 并且在CNT-S复合材料外表面包覆有一层石墨烯。电化学测试结果表明, 这种包覆结构能显著提高CNT-S复合材料的锂硫电池性能。     

石墨烯/硫酸铅复合材料的制备及其在铅酸电池中的电化学性能

利用简单的浸渍法制备了石墨烯/硫酸铅复合材料,使得硫酸铅可以直接用作铅酸电池负极材料。该复合材料分别以100 mA·g^-1、200 mA·g^-1和300 mA·g^-1电流密度放电时,平均放电比容量分别可达到110、94和69 mAh·g^-1,而硫酸铅仅为49、5和0.5 mAh·g^-1,显示出复合材料在高倍率充放电下更好的比容量和再接受充电能力。循环伏安测试表明石墨烯的电容效应随扫描速率增大而增强,同时析氢也变得严重,使得复合材料在充放电过程中充电效率比纯硫酸铅低20%。在充放电过程中,石墨烯能够提高硫酸铅1倍以上的放电容量,并将充电电压提高0.1 V。XRD和SEM结果显示硫酸铅均匀分布在石墨烯片层上,没有出现团聚现象。