High energy density and extremely stable supercapacitors based on carbon aerogels with 100% capacitance retention up to 65,000 cycles

Significance This work explores carbon aerogels with a three-dimensional interconnected nanofiber network and rationally designed hierarchical porous structures, which endow the supercapacitors (SCs) with both high energy density and long-term stability, with the goal of practical application. The as-constructed SCs have a high specific capacitance of 297 F ⋅ g –1 at 1 A ⋅ g –1 and remarkable energy density of 14.83 Wh ⋅ kg −1 at 0.60 kW ⋅ kg −1 , both of which are much higher than those of most carbon-based SCs. Significantly, they have an extremely high stability, with capacitance retention of 100% over 65,000 cycles, the best among carbon-based SCs.