Microwave-Assisted Rapid Synthesis of Cu2S/CoO Heterostructured Composites for High-Performance Asymmetric Supercapacitors

Abstract

Transition metal sulfides and oxides are attractive for supercapacitor electrodes due to rich redox sites and high theoretical capacitances. Yet single-phase materials suffer from poor structural stability and slow charge transfer, restricting practical applications. Herein, a facile microwave route is developed to prepare Cu2S/CoO composite electrodes. Experimental results demonstrate that the heterogeneous interface between Cu2S and CoO induces a prominent synergistic effect, which greatly boosts the redox activity of the electrode. The optimized Cu2S/CoO composite exhibits a specific capacitance of 2898 F g−1 at 1 A g−1, and maintains 84.1% of its initial capacitance after 30,000 continuous cycles, revealing remarkable cycling durability. The asymmetric supercapacitor fabricated with the Cu2S/CoO negative electrode delivers an energy density of 186.45 Wh kg−1 at a power density of 800.02 W kg−1, and this performance outperforms most recently reported analogous electrode systems. This research offers a practical route for the fast fabrication of high-performance bimetallic composite electrodes through microwave treatment, and supplies useful references for the structural engineering and performance optimization of advanced electrochemical energy storage materials.