Morphological evolution of carnation flower-like Cu<inf>2</inf>CoSnS<inf>4</inf> battery-type electrodes

Abstract

Transition metal sulfides are the most reliable type of battery electrode material for supercapacitors. Herein, the morphological evolution of Cu2CoSnS4 has been enhanced with different time-varied temperature processes through a one-step solvothermal route. Promoted by its unique carnation flower-like morphology with excellent petals, it achieves an elevated 132.08 mA h g−1 specific capacity at 0.5 A g−1 current density and long lasting stability with only 22.33% loss over 5000 cycles at 5 A g−1. Moreover, a full-cell asymmetric solid-state supercapacitor (ASSC) device has been constructed to demonstrate its practical applications. The fabricated Cu2CoSnS4//AC ASSC device delivers a 131.90 W h kg−1 high energy density for 749.98 W kg−1 power density with an improved stability of 70% and a Coulombic efficiency of 97.98% after 20 000 charge–discharge cycles, demonstrating its potential as a gifted electrode for high-performance supercapacitor applications.