Modified Co4N by B-doping for high-performance hybrid supercapacitors

Abstract

High-performance energy storage systems are becoming essential to cope with the possible energy crisis in the future. Herein, unique hierarchical B-Co₄N have been reasonably designed and synthesized on Ni foam (NF) via a typical chemical reduction strategy. The successful realization of B-doping engineering effectively facilitates ion and electron transport, adding the electrochemically reactive sites, which endow the B-Co₄N-20/NF electrode with high specific capacity (817.9 C g⁻¹ at 1 A g⁻¹), excellent rate capability (maintained about 90.9% at 10 A g⁻¹) and cycling stability (about 93.06% retention of the initial capacity after 5000 cycles). The corresponding hybrid supercapacitor assembled with B-Co₄N-20/NF electrodes has an energy density of 25.85 W h kg⁻¹ at the power density of 800.2 W kg⁻¹ and a long cycle life (98.59% retention ratio after 5000 cycles). These remarkable properties indicate that the doping of heteroatom and the construction of hierarchical structure will provide a favorable reference for the performance promotion of next-generation energy storage devices.