Cellulose-based activated carbon aerogels as electrode materials for high capacitance performance supercapacitors

Abstract

Carbon aerogels (CAs), as a low-cost and high-performance carbon material, have attracted wide interest as electrode materials for supercapacitors (SCs). Here, a CA was built as a highly interconnected lamellar network by activation. The activation process was achieved using different ratios of activators (ZnCl₂ and KOH) mixed with them and then carbonized. CA-KOH-3 has greatly improved the specific surface area from 616.97 m² g⁻¹ to 1709.62 m² g⁻¹. It also showed the highest capacitance performance, which could reach 213.53 F g⁻¹, and an SC assembled with it showed good energy density performance. Meanwhile, the specific capacitance exceeded its starting value even after 5000 times of charging and discharging. The research shows that a high proportion of KOH in a certain range is conducive to etching micropores and increasing the specific surface area, thus improving the capacitance characteristics. This provides an option for effectively adjusting the porous structure of CA, thereby increasing the specific surface area and improving the capacitance performance.