The application of biomass-based carbon materials in flexible all-solid supercapacitors

Four different kinds of carbon materials were synthesized successfully from saussurea involucrata, cotton stalk and cellulose by two activation methods (KOH-chemical activation method and mixed molten-salt synthesis). Carbon structures, electrochemical and flexible properties are studied. The saussurea involucrata-based flexible symmetric all-solid states supercapacitor exhibited high electrochemical performances, including high specific capacitance (129 F g−1 at 2 mV s−1) and excellent cycle stability (∼ 85% capacitance retention even after 10,000 cycles). More importantly, it also displays excellent bending endurance, the specific capacitance is almost unchanged after 100 bends. This study shows promising materials in symmetric all-solid state supercapacitor applications.