Redox-active mesoporous carbon nanosheet with rich cracks for high-performance electrochemical energy storage

Construction of ordered mesoporous carbon (OMC) with two-dimensional morphology and rich redox functionalities may offer the possibility for improving the supercapacitive performances of the OMC-based electrode materials in capacity and rate performance. Herein, a simple approach by assembly soluble phenolic resin with surfactant of F127 on a self-made magnesium hydroxide was developed and applied to the fabrication of ordered mesoporous carbon nanosheet (OMCN). The obtained OMCN possesses weak ordered mesoporous structure, nanosheet morphology, large surface area (1376m(2)/g vs soft-templated OMC of 522m(2)/g), rich cracks and abundant electroactive oxygen functionalities (13.6%). As electrode for supercapacitor, the OMCN exhibits a two times larger capacity than that of OMC (301 F/g vs 151 F/g) and excellent rate performance with capacitance retention of 84% (vs that of OMC of 62%). For aqueous symmetric supercapacitor in 1.0M Na2SO4, the OMCN based electrode achieves an ultrahigh energy density of 25.3 Wh/kg at power density of 2000 W/kg. As cathode material working on the voltage range of 1.5-4.5 V, OMCN also exhibits a superior surface-driven lithium-ion storage performance including large capacity of 140mAh/g at 0.5 A/g (vs that of OMC of 7.6mAh/g), good rate performance and long cycle stability with about 96% capacity retention after 2000 cycles at 2A/g, showing a promising candidate for the electrochemical energy storage. (c) 2019 Elsevier B.V. All rights reserved.