Defect Engineering of Pc@Coni2s4 Nanocomposites for High-Performance Supercapacitors

Abstract

Vacancy engineering serves as a powerful method to modulate the electronic transport characteristics of electrode materials and has emerged as a widely adopted approach to enhance the performance of supercapacitor electrodes. In this study, the eggplant-derived carbon (PC) was used as the matrix material, and the PC@CoNi2S4 composites was pre-prepared. Subsequently, the target sample, γ-PC@CoNi2S4 electrode materials containing sulfur vacancies, was obtained through a simple soaking process. Characterization results reveal that, under the influence of the excellent conductivity and chemical stability of PC carrier, the high capacitance of CoNi2S4 active substance, and the abundant active sites introduced by sulfur vacancies, γ-PC@CoNi2S4 exhibits outstanding electrochemical performance. Specifically, it achieves a specific capacitance of 1838.94 F g−1 at 1 A g−1 and retains an exceptionally high rate capability of 73.9% at 50 A g−1. Furthermore, a supercapacitor device assembled with γ-PC@CoNi2S4 and activated carbon (AC) reaches an energy density of 50 Wh kg−1 at a power density of 924.14 W kg−1. This study provides valuable insights for desiging and constructing high-performance supercapacitor electrode materials.

Keywords: CoNi2S4, Electrode, Defect engineering, High rate