Engineered Wood-Derived Porous Hydrogel Composites for High-Performance Anisotropic Polyelectrolytes in Flexible Electronic Devices

Natural wood has long inspired the development of artificial biomimetic and bioinspired materials aimed at enhancing human life. However, a major challenge lies in developing straightforward and versatile approaches for producing high-performance, porous wood-derived materials. In this work, we introduce a space-confined porogen photochemistry strategy for engineering wood-derived porous hydrogel composites. Under light irradiation, the nitrogen gas release and the liquid precursor rapidly solidify into hydrogels within 30 s, facilitating in situ pore formation within the wood template. The integration of aligned wood structures with hydrogel multinetworks yields a composite material capable of sustaining a maximum stress of 7 MPa at a critical strain of 200%, with a high porosity of 70%. The anisotropic nature enhances directional ion transport and sensing with performance further tunable by adjusting porosity. This capability positions these materials as promising candidates for flexible zinc-air batteries, which demonstrate a higher output voltage and power density. Additionally, the superior mechanical integrity and water-retention abilities extend the battery life (up to ∼120 h) and support flexibility, as shown by 1000 cycles in bending tests. This space-confined porogen photochemistry approach and the resulting wood-derived composites are poised to make a significant impact in fields spanning energy storage, sensing technologies, and beyond.