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

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. Carbon aerogels with 3D hierarchical porous structure were successfully fabricated. CA-AA exhibited 138 F g-1 at 1 A g-1 superior to cellulose-based active carbon. During 5000 cycles at 1 A g-1, the capacitance retention ratio of CA-AA exceeds 100%.