All‐Wood‐Based Structural Supercapacitors

ABSTRACT Natural wood is an excellent lightweight and renewable structural material, and recent studies have also demonstrated its potential as an electrode matrix for energy storage owing to its inherently porous structure. However, most existing wood‐based electrochemical storage devices overlook the load‐bearing capability of wood. In this work, we construct an all‐wood‐based structural supercapacitor, realizing the synergistic integration of wood as both a structural material and an energy storage device. The device is fabricated using delignified wood as a three‐dimensional scaffold, with its pore walls uniformly coated with carbon nanotubes and poly(3,4‐ethylenedioxythiophene) (PEDOT), thereby imparting both energy storage capability and electronic conductivity. Combined with a high‐strength bicontinuous phase electrolyte, the result is an integrated structural supercapacitor with both excellent mechanical load‐bearing performance and efficient energy storage capability. Benefiting from the intrinsic mechanical robustness of wood and the strength of the electrolyte, the supercapacitor demonstrates outstanding mechanical properties, including a bending modulus of up to 467.1 MPa and a bending strength of 14.1 MPa. Meanwhile, the well‐preserved porous architecture of the wood matrix and uniform distribution of electroactive materials impart high electrochemical performance, achieving an areal specific capacitance of 112.0 mF cm −2 , a maximum energy density of 0.011 mWh cm −2 , and a maximum power density of 0.029 mW cm −2 . This all‐wood‐based supercapacitor not only broadens the application scope of wood but also provides a new strategy for structural‐functional integration, enhanced energy storage efficiency, and sustainable material utilization. image