MXene@ carbonized wood monolithic electrode with hierarchical porous framework for high-performance supercapacitors

Bulk electrodes with sufficient electrochemically active substances promote the enhanced energy density of energy storage devices. Additionally, the pore structure and wettability regulation of the electrodes are key factors in determining the electrochemical performance of the device. Herein, a monolithic electrode (CW/MXene) with a dual utilization strategy for the hierarchical porous structure of carbonized wood (CW) and the high electrical conductivity as well as wettability of MXene was proposed. The combination of MXene and CW provides a hierarchical pore structure with enhanced wettability to the electrolyte to complete the electrochemical reaction. CW/MXene showed the impressive electrochemical performance of 14.48 F cm−2 (203.94 F g−1) at a current density of 1 mA cm−2. Moreover, the obtained symmetric supercapacitor exhibits high areal/specific capacitances of 4.24 F cm−2 (80.61 F g−1) at 1.0 mA cm−2 and high energy densities of 0.589 mWh cm−2/11.2 Wh kg−1. This work provides advanced multiple utilization and excellent electrochemical performance for ultra-thick carbonized wood electrode applications in supercapacitors.