High Performance Supercapacitors from Hierarchical Porous Carbon Aerogels Based on Sliced Bread

Supercapacitor electrodes with porous structure based on renewable, eco‐friendly and cost‐effective materials have caused extensive concern in energy storage fields. Sliced bread, the common food ingredient, mainly containing glucose polymers, can be a promising candidate to fabricate porous supercapacitor electrodes. Highly porous carbon aerogels by using sliced bread as the raw material were synthesized through a carefully controlled aerogel carbonization‐activation process. Interestingly, the specific surface area and the pore size distribution of the porous carbon were controlled by the activation temperature, which result in the varied performance of the carbon aerogel as a supercapacitor. Electrochemical investigation measurements revealed that the hierarchical porous carbon aerogel shows an excellent capacitor behavior for construction of a symmetric supercapacitor, which demonstrated a high specific capacitance of 229 F•g −1 at discharge current of 0.2 A•g −1 . In addition, the fabricated supercapacitor displayed excellent capacitance retention of 95.5% over 5000 cycles.