Enhanced Semi-interpenetrating Network Quasi-solid Electrolytes Modified by Hollow Porous Nanofibers for Flexible Zinc–Air Batteries

The low ionic conductivity and poor mechanical property of quasi-solid electrolytes (QSEs) have hindered the practical implementation of flexible zinc–air batteries (FZABs) with a higher energy density and a longer working time. Herein, inspired by the robust natural extracellular matrix and good water-retention vacuoles of plant cells, semi-interpenetrating network-structured QSEs composed of rigid quaternary ammonium salt of chitosan-decorated hollow porous polyacrylonitrile-based nanofibers and a soft hydrophilic sodium acrylate (PANa) polymer are fabricated. The cross-linked semi-interpenetrating network structure endows the QSEs with enhanced electrolyte absorption/retention capacity, increased ionic conductivity, and improved mechanical strength. Moreover, the introduction of interconnected hollow porous nanofibers offers favorable water reservoirs and ion-conduction channels to further regulate the OH– flux. As a result, the FZABs assembled with the bioinspired QSEs exhibit a high power density (126 mW cm–2), a long lifespan (100 h), as well as good flexibility. The demonstrated bionic and in situ crosslinking strategies provide enlightening pathways for the design of advanced QSEs for high-performance flexible energy conversion and storage systems.