Construction of bidirectional mass transfer channel of radial section wood electrode and application of supercapacitor

The natural low curvature porous structure (i.e., cell cavities) of wood facilitates the transport of electrolyte ions and the accommodation of functional materials, positioning wood as a potential self-supporting electrode substrate. The radial section exhibits favorable mechanical properties (~11 MPa) and can be produced by continuous rotary cutting. However, the densely arranged fiber structure in the cell wall hinders the entry of functional guest materials and the transport of electrolyte ions, greatly limiting its application in electrode substrates. This study created rich, oriented, and penetrating channels on the radial section by laser drilling, forming bidirectional mass transfer channels in conjunction with the natural cell cavities in the wood electrode, enabling uniform and high loading of the functional nanomaterial MXene (5 mg·cm⁻²) in the wood/MXene. The resultant electrode shows a high specific capacitance of 1265 mF·cm⁻² at a current density of 0.2 mA·cm⁻², and such a specific capacitance can be retained 74.4% while the current density increases 100 folds. The bidirectional mass transfer channel structure design strategy proposed in this study is of great significance for the wide application of radial section wood in the field of energy storage.