Cellulose aerogel-based copper oxide/carbon composite for supercapacitor electrode

Abstract

Carbon composite is one of the most competitive electrode materials for supercapacitor, and improving its energy density remains a significant challenge. The copper oxide/carbon composites with high specific surface area were prepared from the cellulose aerogel loaded with copper salts. The copper oxide/carbon composite electrode material, deriving from copper sulfate, reached a specific capacitance of 1001 F g⁻¹ at 2 A g⁻¹, with an energy density of 139.0 W h kg⁻¹. After 500 cycles, the capacitance retention rate is 98.06%. An asymmetric supercapacitor was assembled using this material as positive electrode material, activated carbon as negative electrode material, and 3.0 M KOH as electrolyte. It exhibited good reversible capacity and low voltage drop loss within a voltage window of 0–1.2 V, and its specific capacitance and energy density achieved 125 F g⁻¹ and 6.3 W h kg⁻¹ at a current density of 0.1 A g⁻¹, respectively.