Constructing Robust and Recyclable Self-Powered Polysaccharides-Based Hydrogels via Adjusting Zn2+/Li+ Bimetallic Networks

The fundamental requirement for self-powered hydrogels used in flexible electronic products encompass excellent mechanical performance and conductivity. However, simultaneously achieving high performance in both aspects remains a significant challenge during the fabrication of self-powered hydrogels. In this work, the robust and recyclable self-powered polysaccharides reinforced polyvinyl alcohol (PVA) networks were established via modulating the ionic channels using the Zn2+/Li+ bimetallic salt solutions. The results demonstrate that the hydrogel equilibrated in bimetallic salt solution of 1M concentration can simultaneously achieves impressive tensile strength of 1.36 MPa, and optimal ionic conductivity of 1.64 S/m, respectively, since that the carboxyl groups on the polysaccharide chains enable to adsorb more metal ions without restricting ionic mobility, as a result of higher conductivity. Leveraging its excellent electrochemical performance, the conductive hydrogels can not only serve as flexible sensing materials with enhanced sensitivity to monitor human motion and facilitate information transmission, but also as the recyclable electrolyte in self-powered hydrogel batteries. Interestingly, the self-powered hydrogel batteries can maintain a stable voltage of 0.82 V, and showed good recyclability, which can restore the original voltage output via a simple salt solution equilibration method, offering significant potential in applications such as wilderness survival, etc. This work provides a novel strategy for the rapid and green preparation of robust, recyclable, and self-powered polysaccharides-based hydrogels