Design and structure optimization of 3D porous graphitic carbon nanosheets for high-performance supercapacitor

Abstract

Abstract The restacking and less pore structure of carbon nanosheets severely prolong ion transport pathways when ions diffuse in vertical direction. Here, we design and fabricate 3D porous graphitic carbon material with synergetic features combining porous nanosheets and fiber network. With the assistant of activation–graphitization effect of bifunctional catalyst K3[Fe(C2O4)3] and fiber framework of melamine foam, glucose-derived ultrathin carbon nanosheets with porous and graphitic structure are supported by fiber skeleton after one-step carbonization. Sufficient ion-accessible micropores, partially graphitic carbon nanosheets and interconnected fiber skeleton can intrinsically optimize ion/electron transport and ensure high level exposure of active surface area for charge accumulation. Therefore, the obtained material possesses high specific capacitance of 354.7 F g−1 at 0.5 A g−1, excellent rate capability of 253.3 F g−1 at 30 A g−1, and outstanding cycling stability of 96.8% retention after 10000 cycles. A high energy density of 24.5 W h kg−1 (at 456.7 W kg−1) is achieved in 1 M Na2SO4. This study not only provides a promising approach for constructing porous graphitic carbon nanosheets, but also opens a new direction to optimize ion/electron transport for high-performance of energy storage.