反应物中锂元素的量对LiFePO4/C电化学性能的影响

以Fe2O3和LiH2PO4为原料,葡萄糖为碳源,采用碳热还原法合成了LiFePO4/C正极材料,考察了反应物中锂元素的量对正极材料LiFePO4/C电化学性能的影响。用X射线衍射、扫描电镜(SEM)和恒电流充放电测试和循环伏安法对正极材料的结构、形貌以及电化学性能进行了研究。结果表明:当反应物中额外添加锂元素的量是理论量的10%时,制得的正极材料的电化学性能最佳,在0.2和1C(1C=170mA/g)的充放电倍率下,首次放电比容量分别为156.3和137.5mAh/g,经过20次充放电循环后,容量基本保持不变。

Effect of Amount of Lithium Element in Reactant on the Electrochemical Properties of LiFePO4/C

LiFePO4/C cathode materials were synthesized by carbothermal reduction method, using Fe2O3, LiH2PO4 as starting materials, glueose as carbon source. The effect of the amount of lithium in reactant on the electrochemical properties of LiFePO4/C cathode materials was investigated. The structure, morphology and electrochemical properties of LiFePO4/C were analyzed by XRD, SEM and galvanostatic charge-discharge method and cyclic voltammetry (CV), respectively. The results indicate that when excess additional amount of lithium element is 10% of theoretical value, the sample has optimal electrochemical properties and exhibits a initial discharge capacity of 156.3 and 137.5 mAh/g at 0.2 and 1 C (1 C=170 mA/g) rates, respectively, there is no significant capacity fade after 20 cycles.