Graphene nanosheet and carbon layer co-decorated Li4Ti5O12 as high-performance anode material for rechargeable lithium-ion batteries

Abstract

In this study, we report a facile strategy for anchoring Li4Ti5O12 (LTO) particles wrapped within carbon shells onto graphene nanosheet (GNS) using the freeze-drying assisted microwave irradiation method. In this designed structure, a conductive three-dimensional network can be formed by connecting the GNS and carbon layer which is benefit for the transport of electron and Li+-ion. When used as anode material for lithium-ion batteries, this hybrid composite exhibits an excellent high-rate performance with specific capacities of 171.5, 168.2, 160.1, 151.7 and 136.4mAhg−1 at various current rates of 1, 2, 5, 10 and 20C, respectively. Furthermore, the specific capacity of the obtained anode still retains 99.6% of the initial value after 20 cycles at 20C. The enhanced battery performance can be attributed to the improved electronic conductivity of each LTO grain via uniform carbon coating and GNS wrapping. As a consequence, this novel strategy developed in this study may open a new way to fabricate other electrodes for advanced renewable energy conversion and storage applications.