Reduced irreversible capacities of graphene oxide-based anodes used for lithium ion batteries via alkali treatment

The large irreversible capacities of graphene oxide-based anodes hinder commercial applications of GO materials although the high specific capacity of it has been universally accepted. In this paper, GO was treated under alkaline condition and the composite consisting of the modified GO and graphite was used as anode for lithium ion batteries (LIBs), resulting in an improved initial coulombic efficiency. Electrochemical tests also showed that the modified GO/graphite electrode possessed 86.0% of initial coulombic efficiency, which was 15% higher than that of pristine GO/graphite electrode. The species and the content of functional groups were investigated via XPS, FTIR characterizations in detail, which certified that the ring-opening reaction of epoxides under alkaline condition could greatly reduce the irreversible capacity of GO/graphite anode, in addition, the reversible capacity was guaranteed at the same time. This modified GO/graphite electrodes in the LIBs exhibit superior rate capability and long cycle life. The uniqueness of this electrode lied in its chemical stability, which benefits from the transition of epoxide group and unstable functional groups removal. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.