LiFePO4 was prepared by template-free hydrothermal synthesis using LiOH,H3PO4 and FeSO4 as raw materials, then mixed with glucose to obtain cathode material LiFePO4/C by heat treating. The results of SEM and XRD tests showed that phase-pure LiFePO4 with fine grain size and good dispersion could be obtained by hydrothermal synthesis without any template or surfactant . When the product cycled in 2.3 ~ 4.2 V, the 0.20 C initial specific discharge capacity was 151.5 mAh/g at 23 TI, the 0.20 C and 0.50 C initial specific discharge capacity at - 20 °C was 103.5 mAh/g and 84.5 mAh/g,respectively, which was 68.3% and 55.8% of the 0.20 C one (at 23 °C) .The fine low-temperature performance could be attributed to the one-dimensional nanometer structure of the sample along the Li+ diffusion path.%以LiOH、H3PO4和FeSO4为原料,用无模板水热法合成LiFePO4,与葡萄糖混合后热处理,得到正极材料LiFePO4/C.XRD、SEM测试结果表明:在无模板剂或表面活性剂的条件下,水热合成法可制得纯相、颗粒细小且分散良好的LiFePO4晶体.产物在2.3～4.2 V循环,23℃时的0.20 C首次放电比容量为151.5 mAh/g,-20C时的0.20 C、0.50 C首次放电比容量分别为103.5 mAh/g和84.5 mAh/g,达到23℃时0.20 C放电比容量的68.3％和55.8％.产物具有良好的低温性能,是因为晶体颗粒在Li+扩散方向上具有一维纳米结构.
展开▼
