MXene/biomass/chitosan carbon aerogel (MBC) with shared cathode and anode for the construction of high-efficiency asymmetric supercapacitor

Abstract

Despite the rapid development of biomass-based carbon aerogels research and specific outcomes have been accomplished, the preparation process requires to be developed further compared with other porous media such as activated carbon and graphene, and there are still many obstacles to overcome before reaching industrial production and practical applications since the competitiveness in terms of mechanical strength, adsorption capacity, and structural stability is weaker. Via using electro-static self-assembly between the negatively charged MXene nanosheets and the positively charged radish flakes infiltrated with salt solution, a strategy is proposed for the in-situ preparation of flexible MXene/biomass/chitosan aerogel (MBC) pseudo-capacitive electrode by hydrothermal methods. The electrode was drived according to the principle of concentration difference permeation (CDP) between MXene nanosheets and radish cells. Under both driving forces, the MXene nanosheets are embedded inside the radish cells. Importantly, the MBC pseudocapacitive electrode doping 6% (MBC-6) by lyophilization annealing exhibits a volumetric specific capacitance of 1801.4 mF/cm3 at a scan rate of 2 mV/s. In addition, the assembled binder-free asymmetrical supercapacitor exhibits an ultra-high volume energy density of 33.4 Wh/L, a capacitance retention rate of 82% and a long cycle life of 50,000 times at a high current density of 10 mA/cm3. A plausible approach for creating energy storage devices with a high energy density and voltage window is presented in this study.