改性天然鳞片石墨锂离子电池负极材料的研究

Study of Surface-modified Natural Flake Graphite for Lithium Ion Batteries

对粒径为12μm的天然鳞片石墨进行表面碳包覆改性,并对包覆前后样品的微观结构和电化学性能进行了研究。结果表明:包覆改性提高了天然石墨的振实密度、表面形貌和电化学性能,在0.1 C、0.2 C、0.5 C、1 C、2 C、5 C和10 C倍率下,对应的可逆容量分别为368.6 mAh/g、362.6 mAh/g、353.8 mAh/g、340.6 mAh/g、298.6 mAh/g、228.2 mAh/g和150.2 mAh/g,相对于天然石墨,可逆容量分别提高了6.2 mAh/g、20.9 mAh/g、31.6 mAh/g、42.1 mAh/g、52.4 mAh/g、80.0 mAh/g和58.0 mAh/g,碳包覆小粒径天然石墨表现出的良好的倍率性能,有望应用于电动车用锂离子电池中。

The natural flake graphite with the particle size of 12 μm was coated by a layer of pitch,and the microstructure and electrochemical performance of natural flake graphite and surface modified graphite were studied. It was showed the surface modified graphite with high tap density,surface morphology and excellent electrochemical performance. The capacities of modified graphite were 3368. 6 mAh /g,362. 6 mAh /g,353. 8 mAh /g,340. 6 mAh /g,298. 6 mAh /g,228. 2 mAh /g and 150. 2 mAh /g,corresponding to the rates 0. 1 C,0. 5 C,1 C,2 C,5 C and 10 C,which increased to 6. 2 mAh /g,20. 9 mAh /g,31. 6 mAh /g,42. 1 mAh /g,52. 4 mAh /g,80. 0 mAh /g and 58. 0 mAh /g,relative to natural graphite. The good rate performance of carbon coated small- sized natural graphite for lithium- ion battery made it a promising candidate as anode materials for electric vehicle dynamic 1ithium- ion batteries.