(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 采用高能球磨结合微波合成工艺，以Li2CO3、FeC2O4∙2H2O、纳米SiO2和葡萄糖为原料合成锂离子电池正极材料Li2FeSiO4/C。利用X射线衍射(XRD)、扫描电镜(SEM)和恒电流充放电测试等方法对该材料的结构、表观形貌及电化学性能进行表征。考察超导电碳黑的添加、微波处理时间以及微波加热温度等对Li2FeSiO4/C材料合成及其性能的影响。结果表明：以超导电碳黑为微波耦合剂，采用微波合成法在650 ℃下处理10 min可快速制备具有正交结构的Li2FeSiO4/C材料；获得的Li2FeSiO4/C材料颗粒细小均匀，具有较好的电化学性能；在60 ℃下以C/20对Li2FeSiO4/C材料进行充放电时，其首次放电容量为121.7 mA∙h/g，10次循环后其放电容量仍保持为119.2 mA∙h/g。
关键字: Li2FeSiO4/C；锂离子电池；正极材料；微波合成
cathode materials for lithium ion battery
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A novel synthetic method of ball milling and microwave synthesis was applied to synthesize Li2FeSiO4/C cathode materials using Li2CO3, FeC2O4∙2H2O-SiO2 and sluwse as the raw material. The prepared samples were characterized by XRD, SEM, and galvanostatic charge-discharge test. The influences of addition of carbon powder, microwave irration time and irration temperature on the synthesis and properties of Li2FeSiO4/C materials were examined. The results show that, using super-P carbon as microwave absorber powder, with Li2FeSiO4/C olivine-phase material can be quickly synthesized by microwave processing at 650 ℃ for 10 min. The obtained materials exhibit uniform and fine particle sizes all has good electrochemical properties. The initial discharge capacity of the prepared Li2FeSiO4/C material is 121.7mA∙h/g at 60 ℃, after 10 cycles, the discharge capacity maintains 119.2 mA∙h/g.
Key words: Li2FeSiO4/C; Li-ion battery; cathode material; microwave synthesis
