High Rate Performance Supercapacitors Based on N, O Co-Doped Hierarchical Porous Carbon Foams Synthesized via Chemical Blowing and Dual Templates

N, O Co-Doped porous carbon materials are promising electrode materials for supercapacitors. However, it is still a challenge to prepare high capacitance performance N, O Co-Doped porous carbon materials with balanced pore structure. In this work, a simple chemical blowing method was developed to produce hierarchal porous carbon materials with Zn(NO3)2 center dot 6H2O and Fe(NO3)3 center dot 9H2O as the foaming agents and precursors of dual templates. Soybean protein isolate served as a self-doping carbon source. The amount of Fe(NO3)3 center dot 9H2O influenced the microstructure, element content and capacitance performance of the obtained porous carbon materials. The optimized sample CZnFe-5 with the addition of 5% Fe(NO3)3 center dot 9H2O displayed the best capacitance performance. The specific capacitance reached 271 F g-1 at 0.2 A g-1 and retained 133 F g-1 at 100 A g-1. The CZnFe-5//CZnFe-5 symmetric supercapacitors delivered a maximum energy density of 16.83 Wh kg-1 and good stability with capacitance retention of 86.33% after 40,000 cycles tests at 50 A g-1. The symmetric supercapacitors exhibited potential applications in lighting LED bulbs with a voltage of 3 V. This work provides a new strategy for the synthesis of hierarchical porous carbon materials for supercapacitors from low-cost biomass products.

Automated summary

This study developed a simple chemical blowing method to prepare hierarchical porous N, O Co-Doped carbon materials with optimized capacitance performance. The symmetric supercapacitors based on these materials exhibited good stability and potential applications in lighting LED bulbs.