LiFeBO_3/C复合物的合成及电化学性能的研究

Synthesis and electrochemical properties of LiFeBO_3/C composite

以氢氧化锂、醋酸亚铁和硼酸为原料,利用柠檬酸作螯合剂和碳源,采用流变相法,合成了新型正极材料LiFeBO_3和LiFeBO_3/C。利用XRD、SEM等对材料的结构和形貌进行表征,结果表明:LiFeBO_3/C在形貌上比LiFeBO_3的颗粒分布更加均匀;电化学性能测试研究结果表明:LiFeBO_3/C样品的循环稳定性较好,具有高的充放电比容量,初始放电比容量为120.3 m Ah/g,具有较高的可逆比容量和优良的循环性能。该正极材料合成原料价格低廉,循环性能好,作为锂离子电池正极材料具有很高的可行性。

Carbon-coated LiFeBO3 composite material was prepared by a rheological phase reaction method and successive annealing procedure. In the synthesis procedure, citric acid was selected as carbon source. The structures and morphologies of LiFeBO3and carbon-coated LiFeBO3 samples were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM） techniques. The effect of carbon coating and the annealing temperature on the structure and electrochemical properties were investigated. The electrochemical tests show that the carbon-coated LiFeBO3 can greatly improve the discharge capacity, rate capability and cycling stability due to the improved electric conductivity. The carbon-coated sample （LiFeBO3/C） shows good electrochemical performance （the initial discharge specific capacity of 120.3 mAh/g at 5 mA/g）. These results indicate that the carbon-coated LiFeBO3 could be a promising cathode material for lithium ion batteries.