Hierarchical Porous Carbon Aerogel Derived from Sodium Alginate for High Performance Electrochemical Capacitor Electrode

To improve the performance of electrochemical capacitors, there is a notable focus on carbon materials characterized by a large surface area, reasonable pore size, pore size distribution, appropriate electronic conductivity, and excellent chemical durability. Herein, the hierarchical porous carbon aerogel originating from sodium alginate (SA) with well-defined porosity are proposed. The resultant hierarchical porous carbon aerogel shows a substantial specific surface area of 2050.6 m2 g−1 with macropores, mesopores and micropores confirmed by techniques such as TEM, SEM, BET, etc., resulting from a sequence of aerogel formation-carbonization-activation. By electrochemical measurement, the hierarchical porous carbon aerogel exhibits a specific capacitance of 204 F g−1 at an operating current density of 0.2 A g−1 employing 6 M KOH aqueous solution. The hierarchical carbon aerogel displays outstanding cycling stability with a 96.2% capacity maintenance for 10,000 cycles at an operating current density of 1 A g−1. This study presents a viable method for for preparing hierarchical porous carbon aerogel derived from biopolymer for electrochemical capacitors.