Engineering hierarchical porous ternary Co-Mn-Cu-S nanodisk arrays for ultra-high-capacity hybrid supercapacitors

Abstract

Transition-metal sulfides have been recognized as one of the promising electrodes for high-performance hybrid supercapacitors (HSCs). However, the poor rate performance and short cycle life heavily impede their practical applications. Herein, an advanced electrode based on hierarchical porous cobalt-manganese-copper sulfide nanodisk arrays (Co-Mn-Cu-S HPNDAs) on Ni foam is fabricated for high-capacity HSCs, using metal-organic frameworks as the self-sacrificial template. The synergistic effects of ternary Co-Mn-Cu sulfides and the hierarchical porous structure endow the as-obtained electrode with fast redox reaction kinetics. As expected, the resultant Co-Mn-Cu-S HPNDAs electrode delivers an ultrahigh specific capacity of 536.8 mAh g^-1 (3865 F g^-1) at 2 A g^-1 with a superb rate performance of 63% capacity retention at 30 A g^-1. Remarkably, an energy density of 63.8 W h kg^-1 at a power density of 743 W kg^-1 with a long cycle life is also achieved with the quasi-solid-state Co-Mn-Cu-S HPNDAs//ZIF-8-derived carbon HSC. This work offers a new pathway to fabricate high-performance multiple transition-metal-sulfide-based electrode materials for energy storage devices.

Keywords: Co-Mn-Cu-S; Hierarchical porous structure; Hybrid supercapacitors; Nanodisk arrays; Ultra-high capacity.