Graphene@hierarchical meso-/microporous carbon for ultrahigh energy density lithium-ion capacitors

Li-ion capacitors (LICs) are promising devices to realize the high energy density at high power density. Unfortunately, the development of high energy density LICs is hindered by the low capacity of capacitor-type cathode. Herein, we design a graphene@hierarchical meso-/microporous carbon (G@HMMC) with rational oxygen containing group for ultrahigh energy density LICs. In the ingenious designed G@HMMC material, the novel hierarchical meso-/microporous carbon provides abundant adsorption sites, the graphene structure provides high-speed channel for electron, and rational oxygen-containing group enhances the specific capacity. Therefore, the ingenious designed lithium-ion capacitor composed of G@HMMC cathode and pre-lithiated graphite anode demonstrates ultrahigh energy densities of 233.3 -143.8Wh kg(-1) at power densities from 450.4 to 15686 W kg(-1). Consequently, the G@HMMC material is one of the most promising cathode materials for LICs. The simultaneous manipulation of hierarchical meso-/microporous structure, sp(2) type carbon, and oxygen-containing group provides new opportunities for the high-performance electrodes. (c) 2018 Published by Elsevier Ltd.