Recent progress of battery grade metal sulfides for hybrid energy storage devices

The modern technology-based hybrid energy storage devices (HESDs) in recent times, due to excelling collective features of secondary batteries (SBs) and supercapacitors, have attained the remarkable attention of scientific community throughout the globe. The metal sulfides and their composites among all electrode materials owing to their viable electrochemical characteristics have been recognized as important contender for hybrid devices. In this regard, our work reports the recently utilized single, binary, and ternary composites of metal sulfides as battery grade electrode material for HESDs. Along with synthesis routes including hydrothermal, electrodeposition, solvothermal, microwave, and sonochemical process. Apart from this, different electrochemical characterizations such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge discharge (GCD) have been conferred in this review. Furthermore, the electrochemical performance of sulfide-based HESDs has compared and summarized. The high energy outcomes, current challenges, and future prospects of metal sulfides as electrode material have also been discussed.