High yield production of 3D graphene powders by thermal chemical vapor deposition and application as highly efficient conductive additive of lithium ion battery electrodes

Abstract

With respect to the application of powdered graphene sheets, agglomeration is a troublesome problem. Another problem is that the conventional production method generates a huge amount of harmful wastewater, which brings about unbearable environmental and cost problems. It is thus of great significance to explore novel structure and massive production methods of powdered graphene. Here, we report growth of vertical graphene sheets (VGSs) on carbon black (CB) by thermal chemical vapor deposition, which forms a novel three-dimensional graphene powders (3DGPs). High yield growth of the VGSs at kilograms scale is achieved by increasing the substrate area. As a demonstration, the 3DGPs are used as conductive additive of lithium ion battery electrodes, which show excellent electrochemical performance. The rate performance of LiFePO4 electrode with 1.0 wt% 3DGPs is even better than that with 10.0 wt% CB measured in half-cells. The soft-pack full cells assembled using commercial LiFePO4 and graphite electrodes with 1.3 wt% 3DGPs possess 542.8 mAh with 93.3% retention after 400 cycles at 0.2C, and 85.4% retention after 1000 cycles at 1C. The novel 3DGPs also hold high promise in many other applications such as various composite materials, coatings, and electrochemical electrodes.