Facile and sustainable synthesis of sugarcane-derived binderless self-supported porous carbon membrane for advanced electrode materials

Powder biomass-derived electrodes have been extensively explored and used in capacitor devices, but there are still problems in practice, such as complicated electrode assembly processes and insufficient capacitance with larger current density. We proposed an advanced approach for producing porous carbon membranes derived from sugarcane that could be directly mounted as flexible binderless self-supported electrodes. A sugarcane-derived porous carbon membrane (SPCM) was simply prepared by freeze-drying followed and carbonization with KOH as an activator. The specific surface area of SPCM was 459.5m² g-1, and the main elements were N (2.05 at%), O (21.45 at%), and C (73.62 at%). Compared with other biomass materials, it possessed a highly porous, multi-level structure and contained abundant nitrogen and oxygen functional groups, which facilitate ion adsorption and rapid electron transfer. Consequently, the symmetrical SPCM electrodes exhibit favorable electrochemical characteristics, at a current density of 0.5Ag-1, the specific capacitance measured at 248.0Fg-1. Additionally, the energy density reached 8.6Whkg-1 at a power density of 83.3Wkg-1, and the power density of 1666.7Wkg-1 was attained at an energy density of 1.9Whkg-1. [Display omitted] •A porous carbon membrane was prepared with sugarcane.•A flexible binderless self-supported electrode improved conductivity and stability.•Symmetric electrodes exhibited high areal capacitance of 248.0Fg-1 at 0.5Ag-1.•The symmetric electrodes delivered an energy density of 8.6Whkg-1 at 83.3Wkg-1.