Hierarchical porous carbon aerogels as a versatile electrode material for high-stability supercapacitors

Abstract

Supercapacitors (SCs), as new energy storage devices with low cost and high performance, urgently require an electrode material with good pore structure and developed graphitization. Herein, we report a 3D hierarchical porous structured carbon aerogel (CA) obtained via dissolving-gelling and a subsequent carbonizing process. The gelling process was realized by using different types of anti-solvents. The carbon aerogel-acetic acid (CA-AA) has a specific surface area of 616.97 m² g⁻¹ and a specific capacitance of 138 F g⁻¹ which is superior to cellulose-based active carbon. The CA was assembled into a SC, which showed excellent cycle stability. After charging and discharging 5000 times at the current density of 1 A g⁻¹, the capacitance retention ratio of CA-AA reaches 102%. In addition, CA-AA has an energy density of 10.06 W h kg⁻¹ when the power density is 181.06 W kg⁻¹. It provides a choice for non-activation to effectively regulate the porous structure of biomass carbon materials.