Self-template bagasse-based porous carbons for high performance supercapacitors

Developing the unique structure of biomass as a template is beneficial for promoting the commercial application of template-based hierarchical porous carbon materials. Herein, self-template bagasse-based porous carbons with high capacitance performance are successfully synthesized though low-temperature carbonization to fix the original vascular bundle structure of the bagasse and high-temperature activated carbonization to obtain hierarchical porous structures in the tube wall. As electrode materials for supercapacitors, the as-fabricated self-template porous carbons display a high specific surface of 1351.7 m2 g−1, abundant oxygen functional groups of 17.33%, an ultrahigh specific capacitance of 418.5 F g−1 at 0.5 A g−1 and a good rate performance of 63.1% at a current density ranging from 0.5 to 10 A g−1, which is mainly attributed to both natural and synthetic hierarchical porous structures in the obtained samples. Moreover, the self-template bagasse-based porous carbon devices also possess a remarkable energy density of 14.5 Wh kg−1 at 125 W kg−1 and good cycling stability of up to 98.9% after 10,000 cycles at 2 A g−1. The design strategy described in this work offers a method to further simplify the template synthesis steps, while improving the performance, of biomass-based hierarchical porous carbons. Therefore, these materials can be developed as high capacitance electrodes for energy storage applications.