H2气氛中LiFeO4的制备及其电化学性能研究

摘要

以Fe2O3为铁源在H2气氛中合成了LiFePO4正极材料,X-粉末衍射光谱表明产物为单相的橄榄石型的LiFePO4.热重分析结果表明产物中的铁主要以二价铁形式存在.用循环伏安和充放电测试的方法对样品的电化学性能进行了研究.循环伏安测试发现样品在10周内基本上无变化,产品的首次放电容量为117 mAh/g,放电电压平台为3.2～3.3 V,这与传统的草酸亚铁分解法在同样的条件下所得样品具有可比性.%Lithium iron phosphate is synthesized from ferric oxide by a solid state reaction in hydrogen atmosphere.X-ray powder diffraction (XRD) spectrum indicates that the product has a single phase LiFePO4 with olivine structure. The thermo-gravimetric analysis (TG) shows that the iron in the product is nearly all ferrous. The electrochemical property of the product is also probed by the cyclic voltammetry (CV) and by the charge-discharge of simulated cell. The CV curves in 10 cycles are nearly all the same without any change. The initial discharge capacity of the product is 117 mAh/g and its discharge potential plateau is 3.2～3.3 V, which could be comparable to that made by the decomposition of ferrous oxalate under the same conditions.