非化学计量比尖晶石型锂离子电池正极材料的合成与表征  

Synthesis and characterization of non-stoichiometric spinel as anode for rechargeable lithium-ion battery

作　　者：田从学[1] 张昭[1] 侯隽[1] 李海[1] 

机构地区：[1]四川大学化工学院

出　　处：《化工学报》2006年第4期937-942,共6页CIESC Journal

基　　金：四川省应用基础基金项目(02GY029031);国家自然科学基金项目(50274056).~~

摘　　要：采用阴阳离子复合掺杂,以共沉淀法、超声共沉淀法、Pechini法和高温固相法合成掺杂锰酸锂前驱体,使用三段热处理方式,即650℃预烧、780℃烧结、550℃回火制备掺杂非化学计量尖晶石Li1.05Co0.05Ni0.05Mn1.9O3.9F0.1.通过化学容量分析测定Mn含量和平均价态,用粒度分布、电镜扫描(SEM)、X射线衍射(XRD)、电化学性能测试对产物进行表征.结果表明产物的Mn含量和平均价态与理论值吻合.比较各种合成方法,超声共沉淀法产物的粒径分布最窄、比表面积最小(0.96m2·g-1)、晶型完整、衍射强度最大、结晶性能最佳、晶格常数a为0.821nm、晶粒尺寸L为57.78nm.经装配电池电化学性能测定,超声共沉淀法产物的初始容量更高,循环性能更稳定,经30次循环后容量衰减仅9.3%.The precursors of non-stoichiometric spinel Li1.05 Co0.05 Ni0.05 Mn1.9O2.9 F0.1 were prepared by coprecipitation, supersonic irradiation coprecipitation, the Pechini method and high temperature solid phase reaction separately according to adulteration of anion-cation combination, then the precursors were treated by three-step heat-treatment , i. e. pre-annealing at 650℃, annealing at 780℃ and backfiring at 550℃. The content of manganese and the average chemical valence in spinel were determined by volumetric analysis, and the as-prepared powders were characterized with granularity distribution, X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical performance test. The results showed that the content of manganese and the average chemical valence fitted well with the theoretical value. In contrast with the products prepared by coprecipitation, the Pechini method and high temperature solid phase reaction, the product synthesized by supersonic irradiation coprecipitation had the narrowest granularity distribution, and the smallest volumetric surface area （0.96 m^2·g^-1）. The intensity value of XRD was the highest, so was its crystallinity, and its lattice constant was 0. 821 nm and grain size was 57.78 nm according to the Scherrer equation. The powders prepared by supersonic irradiation coprecipitation had higher capacity and static cycle life by capacity test than that of the three others which was only reduced by 9.3% after 30 cycles.

关 键 词：非化学计量比 超声辐照 共沉淀法 Pechini法 高温固相法 尖晶石Li1.05Co0.05Ni0.05Mn1.9O3.9F0.1 

分 类 号：TM911[电气工程—电力电子与电力传动] TQ110.6[化学工程—无机化工]