石墨烯包覆LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2正极材料的性能

Performance of graphene-coated LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2 cathode material

以共沉淀法制备LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2为基体,通过机械球磨制备石墨烯包覆的LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2正极材料。用SEM、XRD和电化学性能测试研究材料的形貌、晶体结构和电化学性能。制备的石墨烯包覆LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2正极材料具有较好的倍率特性和循环性能:200℃热处理的1.0%石墨烯包覆样品,在3.0~4.3 V充放电,4.0 C放电比容量达到144.3 mAh/g,比基体材料提高16.1%;以1.0 C循环100次的放电比容量达到151.2 mAh/g,循环性能良好。

Using co-precipitation method preparing LiNi0.6Co0.2Mn0.2O2 as the matrix, the graphene-coated LiNi0.6Co0.2Mn0.2O2cathode material was prepared by mechanical ball milling. Morphology, crystal structure and electrochemical performance of the graphene-coated samples were investigated by SEM, XRD and electrochemical performance tests. The graphene-coated LiNi0.6Co0.2Mn0.2O2 samples had better rate capability and cycle performance. After the 1.0% graphene-coated samples were treated at 200 ℃, the specific discharge capacity was 144. 3 mAh/g at 4. 0 C rate in 3.0 -4. 3 V, which was 16. 1% higher than the matrix; the specific discharge capacity of the samples was up to 151.2 mAh/g after cycled 100 times at 1.0 C rate.