表面包覆保护的离子电池新型正极材料LiFeBO_3电化学性能

The Electrochemical Performance of Surface Protected LiFeBO_3 Cathode Materials for Li-ion Batteries

以偏硼酸锂和草酸亚铁为原料,采用固相反应,合成了用于动力锂离子电池新型正极材料L iFeBO3,并用乙丙共聚物(EPM)对该材料进行包覆保护处理;采用XRD、SEM和元素分析等测试技术对样品进行表征。实验表明,L iFeBO3具有较高的放电重量比容量,而且包覆EPM后的硼酸铁锂具有更好的电化学性能,5%EPM包覆的硼酸锂首次放电容量达190 mA.h/g,0.5 C下充放电循环50次后容量衰减只有4.2%。

The LiFeBO3 cathode materials for Li-ion batteries were prepared by means of solid reaction using lithium metaborate and ferrous oxalate as raw materials.The LiFeBO3 cathode materials were further coated by ethylene propylene copolymer（EPM）.The samples were characterized by X-ray diffraction,scanning electron microscopy,and titration analysis.Electrochemical tests of materials showed that LiFeBO3 exhibited a higher discharge mass specific capacity.The electrochemical performance of the coated samples was demonstrated to be improved.Sample coated with 5%EPM had an initial capacity of 190 mA·h/g.It was found that only 4.2% capacity was lost after 50 charge/discharge cyclings at 0.5C.