Drive towards Sonochemically Synthesized Ternary Metal Sulfide for High‐Energy Supercapattery

The present research focuses on, combining the chemistry of supercapacitors and batteries to get highly efficient hybrid energy storage devices. For projected drive, a novel battery‐grade electrode material is introduced. In this regard, binary and ternary metal sulfides with different compositions are synthesized via a facile sonochemical route. The electrode material Co(25%)Cu(75%)MnS (S4) reveals prime electrochemical performance, possessing a maximum specific capacity of 503.5 C g−1 while operating at 0.5 A g−1 in a three‐electrode assembly. The charge storage performance is further scrutinized in a two‐electrode assembly. A supercapattery device (S4//AC) is fabricated by coupling the Co(25%)Cu(75%)MnS (positive) and activated carbon (negative) electrodes. The device displays outstanding energy storage performance with an ultrahigh energy density of 88.71 Wh kg−1 along with a power density of 320 W kg−1. The maximum power density delivered by the assembled supercapattery device is 8000 W kg−1 in parallel with an energy density of 20 Wh kg−1. The supercapattery device also demonstrates an excellent cyclic stability potential of 84% after 3000 continuous charge/discharge cycles. The outstanding outcomes of the fabricated device reveals its potential applications in high‐performance energy storage technologies.