One‐Step Solvothermal Synthesis of VS 4 @PC/rGO for High‐Performance Symmetric Supercapacitors

ABSTRACT Global fossil fuel depletion and renewable energy intermittency, coupled with the rapid development of portable electronics, drive the demand for high‐performance supercapacitors, yet their application is limited by the performance of electrode materials. Transition metal sulfides (TMSs) with high redox activity and unique structures are promising SC electrode candidates, but pristine TMSs suffer from poor conductivity, agglomeration, and cyclic structural degradation. Herein, vanadium tetrasulfide (VS 4 ) with unique rod‐like structure was integrated with porous carbon (PC) and reduced graphene oxide (rGO) to fabricate VS 4 @PC/rGO ternary composites via a one‐step solvothermal method. PC and rGO uniformly distribute on/around VS 4 rods, forming a skewer‐like structure that mitigates agglomeration, enhances the specific surface area, and accelerates ion/electron transport. The VS 4 @PC/rGO‐25% electrode exhibits the highest specific capacitance of 325.8 F·g −1 at 0.5 A·g −1 , outperforming binary VS 4 @PC (241 F·g −1 ) and VS 4 @rGO (258 F·g −1 ). The assembled symmetric supercapacitors deliver 46.1 Wh·kg −1 at 374.8 W·kg −1 and, more notably, maintains exceptional long‐cycle stability. After 10,000 charge–discharge cycles, it still retains 86.3% of its initial capacitance with a coulombic efficiency of 96.4%, demonstrating great potential for long‐term practical energy storage applications. This work not only highlights the potential of VS 4 ‐a representative TMS as a high‐performance electrode material but also provides a generalizable strategy for addressing the intrinsic limitations of TMSs via rational composite design with carbonaceous materials.