Rhenium Sulfide Incorporated in Molybdenum Sulfide Nanosheets for High-Performance Symmetric Supercapacitors with Enhanced Capacitance.

Abstract

Supercapacitors are considered potential energy storage devices and have drawn significant attention due to their superior intrinsic advantages. Herein, we report the synthesis of ReS2 embedded in MoS2 nanosheets (RMS-31) by a hydrothermal technique. The prepared RMS-31 electrode material demonstrated superior pseudocapacitive behavior in 1 M KOH electrolyte solution, which is confirmed by the heterostructure of RMS-31 nanosheet architectures. RMS-31 has a specific capacitance of 244 F g-1 at a current density of 1 A g-1 and a greater areal capacitance of 540 mF cm-2 at a current density of 5 mA cm-2. The symmetric supercapacitor device with the RMS-31 electrode delivers an energy density of 28 W h cm-2 with a power density of 1 W cm-2 and reveals long-term stability at a constant current density of 5 mA cm-2 for 10,000 cycles while accomplishing a retention of 66.5%. The high performance of this symmetric device is attributed to the synergistic effect of ReS2 and MoS2 and the presence of the metallic 1T-MoS2 phase in the RMS-31 electrode. To the best of our knowledge, this is the first report of increasing the interlayer spacing of 2H-MoS2 by incorporating ReS2 for symmetric supercapacitor applications.