Li_3V_2(PO_4)_3的制备及其电化学性能研究

以磷酸二氢锂为锂源和磷酸根源、五氧化二钒为钒源,硬脂酸为还原剂和表面活性剂,采用球磨加碳热还原法制备锂离子电池正极材料Li_3V_2(PO_4)_3/C复合材料。采用X射线衍射光谱法(XRD)对样品进行了物相分析,用扫描电子显微镜法(SEM)对样品形貌和粒径进行了表征,用恒流充放电蓝电测试仪对材料的电化学性能进行了测试。结果表明:烧结温度700℃时产品循环性能和倍率性能最佳。在3.0~4.3 V电压范围内,0.1 C、0.5 C下,首次放电比容量分别为115.2、108.7 mAh/g,循环50次、17次后容量保持率分别为96.7%、101.4%,呈现了良好的循环性能。

Synthesis and electrochemical characteristics of lithium vanadium phosphate

Li3V2(PO4)3/C was synthesized by carbon-thermal reduction method,using LiH2PO4 as the lithium source and phosphate source,V2O5 as vanadium source,stearic acid as reductant,carbon source and surface active agent.The structure and electrochemical performance of the samples were characterized by XRD,SEM and electrochemical performance testing.The results indicate that the samples have better cycling and rate performance at the calcination temperature of 700 ℃.The first discharge capacity of the samples are 115.2 and 108.7 mAh/g at 0.1 C and 0.5 C with the capacity retention of 96.7％ and 101.4％ after 50 and 17 cycles,respectively.