Simultaneous Enhancement of the Performance and Stability of MnO2 Based Lithium Ion Battery Anodes by Compositing with Fluorine Terminated Functionalized Graphene Oxide

摘要

Metal oxide based anodes for lithium ion batteries should theoretically exhibit high specific capacities, but their disappointing experimentally measured capacities and cycle stabilities inhibit their usages in the commercial and industrial level. Here, we propose a simple method to process the MnO2/ 2,2,3,3,4,4,4-Heptafluorobutylamine-functionalized-grapheneoxide( HFBA-fGO) composite anode, in which HFBA-fGO is composited with the MnO2 based anode to simultaneously enhance the specific capacity to reach the theoretical capacity of MnO2 and improve the cyclic stability significantly. In fact, the MnO2/HFBA-fGO composite anode exhibits high performance with specific capacity of 1030 mAhg1 under 100 mAg1 and stable cyclic performance at least up to 200 cycles of repeated charging and discharging even at a high rate of 1 A g1. A detailed analysis of the enhanced cyclic stability of the composite anode is performed through the investigation of the electrode-electrolyte interfaces using the electrochemical impedance spectroscopy and cyclic voltammetry. Such results were possible because of the significantly suppressed irreversible formation of the surface passivation layer caused by the fluorine-rich terminal groups of the HFBA-fGO, which leads to enhanced cyclic stability. We believe that this method should be effective even for other various metal-oxide anodes besides MnO2 as well, which certainly broadens the potential use of HFBA-fGO.