Lignin-based interfacial engineering of copper nanowire/bacterial cellulose composite carbon aerogels for flexible pressure sensing and energy storage.

Flexible electronic devices urgently require materials that integrate high electrical conductivity with superior mechanical flexibility. Aerogels find extensive applications in the field of biomass-based flexible pressure sensors. However, aerogels fabricated by combining conventional metallic nanomaterials with bacterial cellulose (BC) often exhibit inadequate mechanical properties. To address this limitation, this study proposes a novel composite strategy based on atom transfer radical polymerization (ATRP)-modified lignin, copper nanowires (CuNWs), and BC to construct multifunctional carbon aerogels that simultaneously achieve high elasticity and high electrical conductivity. In this design, grafted polymer chains of lignin coordinate with CuNWs at one end while forming hydrogen bonds with the BC network at the other. This dual interaction enables precise chemical "anchoring" and uniform dispersion of CuNWs within the three-dimensional porous architecture. The CuNWs/modified lignin/BC composite carbon aerogel (LBrCuA) electrode delivers a high specific capacitance of 505.04 F g-1 at 1 A g-1 in a three-electrode system. After assembling a symmetric capacitor, the specific capacitance at the same current is 200.55 F g-1. It also exhibits good piezoresistive sensitivity, and the peak current response remains stable after 1000 cycles at 50% strain. Simultaneously, it also demonstrates outstanding mechanical properties. After 500 compression cycles at 70% strain, it retains 95.17% of its initial stress; after 2000 cycles at 50% strain, it maintains 71.58% of its initial stress without structural degradation. Compared to unmodified systems or those prepared by conventional physical blending, the LBrCuA developed herein demonstrates significant potential for flexible pressure sensing applications.