Metallic 1T-MoS2 with defect induced additional active edges for high performance supercapacitor application

Abstract

Molybdenum disulphide (MoS₂) is widely explored in the area of electrochemical energy storage devices as an alternative to graphene. Here we introduce a 1T-MoS₂ electrode with defect induced active edges for high performance supercapacitors. The metallic phase (1T) facilitates enhanced electrical conductivity and defect rich morphology that results in a high specific capacitance value. The structural characterisation confirms the formation of 1T phase and defect concentration in the material. Transmission electron microscopy imaging further confirms the presence of defects in high defect density MoS₂ (HDD-MoS₂) and low defect density MoS₂ (LDD-MoS₂). The electrochemical studies show that the prepared high defect density MoS₂ electrode exhibits a maximum specific capacitance of 379 F g⁻¹ and 68.9 F g⁻¹ at 1 A g⁻¹ current density in three and two electrode systems, respectively. The symmetric HDD-MoS₂ supercapacitor exhibits an outstanding cell performance with an energy density of 21.3 W h kg⁻¹, at a power density of 750 W kg⁻¹ and a capacitance retention of 92% after 3000 cycles. These findings suggest that 1T MoS₂ with high defect density can be a potential candidate for high performance supercapacitor electrode application.