Sandwich-like chitosan porous carbon Spheres/MXene composite with high specific capacitance and rate performance for supercapacitors

The application of porous carbon microspheres derived from pure biomass in supercapacitors is restricted due to their limited reactive groups. MXene owns a combination of redox Faradic surface with good metallic conductivity and hydrophilicity, which assists to obtain high pseudocapacitance and energy density. Herein, Ti₃C₂T_x MXene was introduced to chitosan-based porous carbon microsphere (CPCM) to fabricated sandwich-like structure (CPCM/MXene) through electrostatic interaction. The Ti₃C₂T_x protected the spherical structure of CPCM. Meanwhile, CPCM hindered the reaggregation of Ti₃C₂T_x by inserting in the Ti₃C₂T_x layers, promoting the electrolyte migration kinetics. The synergistic effect endowed CPCM/MXene high specific capacitance of 362 F/g at current density of 0.5 A/g and acceptable cycling stability with 93.87% capacitance retention at a high current density of 10 A/g after 10,000 cycles. Furthermore, CPCM/MXene displayed a high energy density of 27.8 W/(h•kg) at 500.0 W/kg of power density. These satisfactory performances prove that combining Ti₃C₂T_x MXene nanosheets with porous carbon microspheres is a considering method to construct a new generation electrode material of supercapacitor.