Enhancing Mechanical and Ionic Transport Properties of Polyvinyl Alcohol Hydrogel Electrolytes Through Zinc...

To overcome the inherent limitations of polyvinyl alcohol (PVA)-based hydrogel electrolytes-including insufficient mechanical strength, low ionic conductivity, and poor cyclic stability-we report a controlled synthesis strategy. By adjusting the precursor stirring temperature and replacing it with Zn²⁺, we succeeded in creating a uniformly sized, evenly distributed zeolite nanofiller. Zn²⁺ doping induces local lattice shrinkage and surface roughening, thereby enhancing the specific surface area, optimizing pore size distribution, and constructing efficient ion transport pathways. When ZnA zeolite was doped into PVA hydrogels, the modified zeolite forms a robust interface with the polymer matrix, significantly improving mechanical flexibility and electrochemical properties. At an optimal load of 10 wt% (PZ-10), the hydrogel strain was 130.7% and the ionic conductivity was 16.6 × 10^-3 S cm^-1-2.2 times higher than that of the undoped control (PZ-0). When assembled as an electrolyte in a zinc-ion hybrid capacitor, PZ-10 has an initial specific capacity of 101 F g^-1 at 1 A g^-1 and retains 85.3% of its capacity after 1000 cycles, a 7.8% improvement over PZ-0. This work provides a scalable strategy for high-performance hydrogel electrolyte engineering, and PZ-10 shows great potential in flexible energy storage applications.