Graphene Platelets and Their Manganese Composites for Lithium Ion Batteries

摘要

In comparison with graphitic carbons, graphene oxide and transition metal oxides can reversibly store/release over twice amount of lithium per mass. In this research, lithium storage characteristics in graphene oxide (GO) and OO/manganese oxide (GO/Mn_3O_4) composites were studied, which are advantageous in terms of low cost and environmental benign. The prepared GO delivered reversible capacity of 790 mAh/g with an average columbic efficiency of 95%. The capacity decreased dramatically after GO was thermally annealed 400°C resulting from the 3D stacking of graphene layers into the turbostratic misalignment. The G0/Mn_3O_4 composites exhibited reversible capacities up to 860 mAh/g based on the total mass, corresponding to 900 mAh per gram of Mn_3O_4 close to theoretical value. The high reversible capacities and good cyclic stability of the GO/Mn_3O_4 composites can be attributed to the formation of nano size particles of Mn_3O_4 and enhanced electronic and mechanical properties in the presence of graphene.