Surface engineered sulvanite integrated with layered double hydroxide for asymmetric hybrid supercapacitor

Abstract

Layered double hydroxides (LDHs) are an emerging material, owing to their unique 2-D flake like morphology giving them a rapid diffusion characteristic. Surface tuning of Cu₃VS₄ sulvanite was performed to obtain various novel 3-D morphologies, to be integrated with 2-D mesoporous Ce^(III)–Mg^(II)–Y^(III) LDH by a facile cost-effective approach. The 3-D structure of sulvanite enhances the surface area and number of active sites around the surface, allowing excellent redox behaviour. The integration of 3-D sulvanite with the 2-D LDH gave rise to a unique synergistic effect, resulting in an outstanding specific capacitance of 1456.6 F g⁻¹ with 98.8% retention of its initial capacitance after 10 000 charge–discharge cycles, for cubic sulvanite integrated LDH (LD-C). A sulvanite LDH asymmetric supercapacitor hybrid (SLASH) device was fabricated using LD-C, showing the specific capacitance of 52.5 F g⁻¹ at 1 A g⁻¹, exhibiting an exceptional power density of 756.8 W Kg⁻¹ at an energy density of 67.2 Wh Kg⁻¹. The device exhibited an outstanding durability of 98.9% after 12 000 charge discharge cycles, displaying capable endurance when applied in real world energy storage applications.