Electrochimica Acta, Vol.309, 228-233, 2019
Reduced graphene oxide@nitrogen doped carbon with enhanced electrochemical performance in lithium ion batteries
Reduced graphene oxide (rGO) has attracted wide attention as anode materials of lithium ion batteries, however, restacking of rGO sheets limits its capacity and rate performance. To address this issue, a sandwich-like composite of N-doped carbon (NDC) and rGO (rGO@NDC) was fabricated via a process of absorbing [EMIm]N(CN)(2) ionic liquid on the surface of graphene oxide (GO) nanosheets and subsequent heat-treating of the composite. The rGO@NDC composite exhibits a high specific capacity of 409.4 mAh g(-1) with a Coulombic efficiency of 100% after 50 cycles at a charge-discharge rate of 0.5 C, and a specific capacity of 222.8 mAh g(-1) with no capacity fade after 1200 cycles at charge-discharge rate of 10 C. Compositing the rGO with NDC particles can decrease the superficial oxygen-containing functional groups of the rGO, and therefore decrease side reactions during battery cycling. And embedding of NDC particles on the surface of rGO sheets avoids the restacking of rGO sheets and enlarges the interlayer space of the rGO to facilitate Li+ transport within the rGO@NDC. Finally, the NDC particles provide more accessible sites for Li+ and rGO sheets as conductivity networks improves electron transport. (C) 2019 Elsevier Ltd. All rights reserved.