Perpendicular edge oriented graphene foam supporting orthogonal TiO2(B) nanosheets as freestanding electrode for lithium ion battery

We report three-dimensional (3D) freestanding electrodes based on edge-oriented multilayer graphene (EOG) foam loaded with oriented TiO2 (B) nanosheets for lithium ion battery that exhibits large capacity and extremely long cycling stability. In contrast to the commonly reported graphene/graphite foams (GFs) that consist of lateral graphene/graphite sheets, EOG foam, with perpendicular graphene network to fully expose the chemically active graphene edges, was developed as a better scaffold to support active materials. Orthogonally oriented TiO2(B) nanosheets were densely grown on the EOG foam but had straight channels for facile electrolyte access, thus producing a rationally-designed nanostructured architecture. Such a TiO2(B)/EOG freestanding electrode demonstrated large capacities and high-rate performance. Particularly, it exhibited unprecedented cycling stability with capacity retention of 82% after 12,000 charge-discharge (C-D) cycles. It is expected this new electrode architecture as well as the EOG foam will find broad applications in further development of high performance lithium ion batteries and other electrochemical energy technologies. (C) 2016 Elsevier Ltd. All rights reserved.