Enhanced electrochemical and thermoelectric performance of bacterial cellulose-based composite aerogels via multi-component reinforcement

Abstract

Flexible wearable electronics demand multifunctional materials with robust mechanical properties, high conductivity, and sensing capabilities. However, existing bacterial cellulose (BC)-based aerogels suffer from poor mechanical stability and limited electrical performance. Here, we report a synergistic, multi-component reinforcement strategy for fabricating high-performance BC-based composite aerogels. By incorporating sodium alginate (SA) as a toughening modifier and integrating dual conductive polymers (poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI)), we construct an ionically cross-linked network via Ca²⁺ chelation. The optimized aerogel (BC : PEDOT = 2 : 1, 30% SA, 4% PANI) demonstrates remarkable multifunctional performance: a specific capacitance of 37.09 F g⁻¹ with 98.3% retention after 10 000 cycles, superior thermoelectric properties (Seebeck coefficient: 0.7 mV K⁻¹, electrical conductivity: 4.5 S cm⁻¹, power factor: 220.5 µW m⁻¹ K⁻²), and stable pressure-responsive behavior (18.5 mV and 6.8 µA at 5 kPa). The composite aerogel exhibits good mechanical properties, with a stress of up to 9.6 kPa at 100% compressive deformation after 100 cycles. The Ca²⁺-mediated ionic cross-linking significantly enhances mechanical robustness compared to pristine BC aerogels, while the synergistic combination of PEDOT and PANI creates continuous electron-transport pathways. This work demonstrates that rational design of multi-component systems can overcome the traditional trade-off between mechanical and electrical properties in BC-based materials, offering a promising approach for next-generation flexible electronics, including self-powered sensors and wearable energy storage devices.