Mn_3O_4/石墨烯复合材料的制备与电化学性能研究

Synthesis and Electrochemical Performance of Mn_3O_4/Graphene Composites

本文以氧化石墨烯(GO)溶液为氧化剂,采用水热法使GO直接氧化Mn(Ac)2制备Mn3O4/石墨烯复合材料,并通过在制备过程中加入氨水提高了复合材料中GO的还原程度与Mn3O4颗粒的分散性.制得的Mn3O4/石墨烯复合材料表现出优异的电化学性能.在0.5 A·g-1的电流密度下复合材料质量比容量可达到850 m Ah·g-1,0.5 A·g-1时充放电循环测试200周容量保持率为99%.

The Mn3O4/Graphene composites were synthesized by hydrothermal method with the in-situ redox reaction of graphene oxide （GO） and manganese acetate （Mn（Ac）2）. The phase structures and morphologies of the materials were character- ized by XRD, SEM and TEM. The XPS and IR techniques were used for studying the residual function groups of reduced graphene oxide （RGO）. The electrochemical performances of the hybrids were tested in a coin cell. Results showed that the com- posites prepared with the addition of ammonia water （RM-A） have better performance. The graphenes in RM-A were better-re- duced and the Mn3O4 particles were much smaller. The Mn3O4/Graphene composites exhibited a high specific capacity with good rate capability and cycle stability. At the test current density of 0.5 A·g-l, the composites demonstrated a capacity of 850 mAh· g-l, and no capacity decays were observed up to 200 cycles.