磷铁制备锂电池材料LiFePO_4的碳包覆优化研究

Optimization of Carbon-coated LiFePO_4 for Manufacture of Ferro-phosphorus Lithium Battery

利用磷化工副产物磷铁和CO2为原料,合成锂离子电池正极材料LiFePO4.通过对不同焙烧温度下葡萄糖的变化以及质量损失分析确定样品碳包覆量,将纯LiFePO4和不同碳包覆量的LiFePO4/C复合材料进行恒电流充放电及循环伏安测试.碳包覆量为4.3wt%的LiFePO4/C放电容量约是未进行碳包覆的纯LiFePO4放电容量的3倍,循环可逆性也更优.本工艺方法简单,成本低廉,实现了变废为宝和低碳环保,为未来生产提供了新思路.

The by-product of phosphorus chemical industry,namely ferro phosphorus and CO_2 are used as the raw material material when LiFePO_4 is synthesized. Carbon coating quantity is determined by analyzing the mass loss rate of glucose after calcination at different temperatures. Then the electrochemical performances of the pure LiFePO_4 and the carbon-coated LiFePO_4/ C composites are tested by charge / discharge tests and cyclic voltammetry. The discharge capacity of the LiFePO_4 with 4. 3wt% carbon coating is about three times as much as that of the pure LiFePO_4,and the cyclic reversibility is much better. This method simplifies the synthesis,reduces the manufacturing costs,converts the wastes into the energy materials and finally protects the environment,innovatively puts forward a new synthesis idea for future production.