卷绕铅酸电池泡沫铅负极电化学行为的研究

以泡沫铅作为负极集流体制备了卷绕VRLA电池.采用计时电流法、循环伏安曲线、电化学阻抗谱和充放电实验研究了泡沫铅负极的电化学行为,结果表明泡沫铅负极的真实表面积比铅箔负极的大,因此泡沫铅负极具有较低的过电势,并且不论是在怎样的放电状态下,泡沫铅负极的电化学反应电阻较小;与铅箔负极相比,在10、5和2小时率放电状态下,泡沫铅负极的质量比容量分别增加25.9%,30.0%和48.2%.此外,SEM观察显示,泡沫铅负极表面活性物质为更加细小的晶体颗粒和具有更高的孔率.     

LiNi0．85Co0．10Al0．05O2正极材料合成及表征

以LiOH·H2O,Ni2O3,Co2O3和Al(OH)3为原料,采用固相反应法合成Co-Al共掺入LiNiO2的化合物LiNi0.85Co0.10Al0.05O2,由TG-DTA,XRD,SEM,DSC和电化学测试表征材料.结果表明,该材料首次放电容量达186.2mAh/g(3.0 V～4.3 V,18 mA/g),10次循环之后,容量还有180.1 mAh/g,容量保持率为96.7%;与未掺杂的LiNiO2相比,该材料显示出良好的循环性能,且热稳定性也有所提高,是一种很有应用前景的锂离子电池正极材料.     

锂离子电池硅基负极材料研究进展

本文主要介绍近年来硅及含硅材料作为锂离子电池负极材料的研究进展，包括硅单质、硅的氧化物以及硅的金属化合物和其它硅基多元化合物；分析了硅基材料作为锂离子电池负极材料存在的问题；阐述了硅基材料作为锂离子电池负极材料的研究前景。     

Electrochemical properties of some cobalt antimonides as anode materi-als for lithium- ion batteries

Some cobalt antimonides have been prepared and studied as the candidate anode materials for lithium ion batter-ies. Reversible capacities of 424,423 and 546 mA·h·g-1 were measured at the first cycle for as-solidified CoSb2, CoSb3 and annealed CoSb3 respectively. A low lithium ions diffusion coefficient in the order of 10-16 m2·s-1 was estimated from the coulometric titration measurements in the annealed CoSb3 electrode. It was found that the electrochemical properties of fine powders are significantly better than coarse powders. However the SEM picture shows that the nano-sized CoSb3 powders gathered to larger granules, which worsens somewhat the capacity retention of the nano-sized materials, although the volume capacities of the annealed and ball milled CoSb3 remain near twice of that of graphite after 50 cycles.     

Preparation and electrochemical properties of LiMn1.95M0.05O4 （M=Cr, Ni）

The preparation process and electrochemical properties of LiMn2O4 and LiMnl.95M0.05O4 （M = Cr, Ni） were studied. The results show that the decomposition temperature range of xerogel prepared with lithium acetate and manganese acetate as raw rnaterials is large and the decomposition speed is slow. Oxygen consumed is apt to get a prompt supplement during the preparation of LiMn2O4, and carbonization of the organic matter can be reduced or avoided, which is favorable to the combination of lithium and manganese. Using lithium acetate, manganese acetate, chromium nitrate, and nickel nitrate as raw materials and adopting the citric acid complexing method, it has been found that the prepared powders have high purity, high quality stability, and even doping characters. With the increase of sintering temperature, the particle size and crystal lattice constant of LiMn1.95M0.05O4 （M = Cr, Ni） enhance. However, the purity of the product is relatively high and has no obvious change, which is advantageous to the control of the quality of LiMn1.95M0.0504 （M = Cr, Ni）. Doping with a small amount of Cr3. and Ni^2＋ can stabilize the spinel structure of LiMn2O4, suppress the Jahn-Teller effect, and improve the cycling properties but reduce the initial capacity.     

Synthesis and characterization of multidoped lithium manganese oxide spinel LiCo0.02La0.01Mn1.97O3.98Cl0.02

1 Introduction The cathode material plays an important role in the performance of lithium ion batteries. Lithium transition metal compounds with layered and spinel structure are favourites among cathode materials for lithium rechargeable batteries. In thi…     

天然石墨／锑复合材料作为锂离子电池负极材料嵌／放锂性能研究

研究了用简单混杂和球磨方法制备的天然石墨／锑复合材料作为锂离子电池负极材料的嵌／放锂性能以及循环过程中嵌／放锂容量衰减机理。复合材料中的锑以独立的可逆嵌／放锂反应参与吸／放锂过程并显著提高复合材料的嵌／放锂容量。较大颗粒的锑在嵌／放锂过程中体积剧变导致颗粒破碎、电接触恶化而渐渐失去嵌／放锂活性，因此由简单混杂所获得石墨／锑复合材料在循环过程中容量逐渐降低；采用球磨方法在天然石墨颗粒表面形成弥散分布的小颗粒锑则能获得具有较高可逆容量和较好的循环稳定性的石墨／锑复合锂离子电池负极材料。     

Preparation of modified LiMn2O4 by solid-state reaction

Modified lithium manganese oxides were prepared by solid-state reaction of LiMn2O4 and LiCoO2 as raw materials. A study was carried out by TG-DSC,XRD, DSC and electrochemical to analyse the reaction process and structural characterization of products. The results show that the LiMn2O4 reacts chemically with LiCoO2 at high temperature. All of Li and partial Co atoms can insert into the LiMn2O4 crystal lattice and a newly formed spinel phase-modified LiMn2O4 was obtained. The distribution of Co content is even in modified LiMN2O4 compound. The modified LiMn2O4 compound exhibits improved cycling stability at room and elevated temperature in comparison with the pure LiMn2O4.     

Synthesis and thermal decomposition kinetics of LiNiO2

A layered LiNiO2 with high crystallinity was synthesized by sintering the finely prepared mixture of lithium hydroxide and nickel hydroxide in the oxygen atmosphere. The electro-chemical properties of LiNiO2 show that it has a reversible capacity of more than 168mA*h*g-1. It was found that with increasing temperature, LiNiO2 decomposed in air followed with three reaction stages, the apparent activation energies were 747.18±1.0kJ*mol-1, 932.46±1.0kJ*mol-1 and 1126.97±1.0kJ*mol-1 respectively, and the kinetic equations of the three reaction stages were obtained.     

Effect of surface modification of metal hydride electrode on performance of MH/Ni batteries

A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.