Crafting nanosheet-built MnCo2S4 disks on robust N-doped carbon matrix for hybrid supercapacitors

Engineering nanostructured architecture with a hierarchically arranged active surface is regarded as an effective strategy to develop advanced electrode materials. Herein, nanosheet-built MnCo2S4 micro-disks with abundant nano-pores are synthesized and uniformly dispersed on a three-dimensional nitrogen-doped carbon matrix (3DNC). In the resultant 3DNC@MnCo2S4 composite architecture, N-doped carbon network provides interconnected and shortened pathways for fast ion transmission and charge transfer, and the nanosheet-built MnCo2S4 disks allow the efficient Faradaic redox process through the increased active surface. Due to the compositional and structural advantages, prepared 3DNC@MnCo2S4 composite architecture delivers a superior electrochemical capacitive performance than 3DNC@MnCo2S4 and other sulphospinel-based electrodes (including a high specific capacitance of 1812 F g(-1) at 1A g(-1), and a high rate performance of 82.9% capacitance retention at 20 A g(-1)). When assembled into hybrid supercapacitor device, the 3DNC@MnCo2S4//AC HSC also exhibits a high energy density of 68.8 Wh kg(-1) at the power density of 800 W kg(-1) and excellent cycling stability (82% capacitance retention after 5000 cycles at the current density of 10 A g(-1)). The facile yet efficient construction of this 3D porous electrode provides an innovative method for developing high-performance energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved.