Novel hierarchical porous carbon prepared by a one-step template route for electric double layer capacitors and Li–Se battery devices

Abstract

Low-cost hierarchical porous carbon materials with a controllable structure and high specific surface area as well as large pore volume were synthesized by a one-step route involving SnO₂@chitosan precursor carbonization and subsequent SnO₂ template removal. We found that when HPC CISC-29 is applied as the electrode in the supercapacitor device, it exhibits both high specific capacity (260.4 F g⁻¹) and excellent rate capacitance retention (81.9%) from 0.1 A g⁻¹ to 10 A g⁻¹. CISC-29 shows superiority compared to conventional activated carbons for which specific capacitance and capacitance retention are 100–200 F g⁻¹ and 60–70%, respectively. Solid-state NMR and NLDFT porosity distribution results reveal that the high specific capacitance is most likely associated with the optimized hierarchical porous structure, e.g. rich small-size micropores and their good connection with large-size mesopores. Finally, CISC-29 was complexed with Se to construct a cathode for lithium selenium batteries. Se@CISC-29 shows excellent performance with a specific capacity of 1207.0 mA h g⁻¹ at 0.1 A g⁻¹.