Synergistic effects of polyoxometalate with MoS2 sheets on multi-walled carbon nanotubes backbone for high-performance supercapacitor

Abstract

The development of high-performance electrochemical energy storage device is important for addressing energy shortage issues. As one of the next-generation energy storage devices, supercapacitor (SCs) material and their composite designs have gained increased attention in recent years. Herein, the CNT@MoS2/PDDA/PMo12 nanocomposite, was assembled via PDDA-assisted (PDDA is poly(dimethyldiallylammonium chloride)) synthesis strategy. The positively charged polyelectrolyte can interact with two negatively charged components, phosphomolybdic acid (PMo12) and CNT@MoS2 (CNT referred to multi-walled carbon nanotubes, and MoS2 referred to molybdenum disulfide) through electrostatic interaction. PMo12 has uniformly attracted on the surface of the ultrathin MoS2 nanosheets-modified CNT, which endowed the nanocomposite with a fast electron transport efficiency, enrich charge storage and multi-electron transfer capabilities. As a symmetric supercapacitor system, this composite exhibited a high rate specific capacitance of 110 F g−1 at 0.5 A g−1 and an energy density of 15.27 W h kg−1 at a power density of 152 W kg−1. Moreover, an excellent cycle performance with 89% specific capacitance after 10000 charge-discharge cycles was obtained.