Performance Optimization and Prospects of Double Network Hydrogels for Flexible Electronic Devices

Dual-network (DN) hydrogels possess tunable polymer network architectures, exceptional mechanical robustness, and superior water retention capability. They demonstrate substantial potential in structural optimization and performance stabilization, thus garnering widespread attention from both the academic and industrial sectors in the field of flexible devices such as supercapacitors, temperature sensors, and zinc-air batteries. Focusing on the gelation mechanisms of DN hydrogels, this review systematically classifies them into three categories according to different cross-linking interactions, namely Chemical crosslinking, physical crosslinking, and hybrid crosslinking. Notably, this review details optimization strategies for the electrical conductivity, temperature resistance, and mechanical properties of DN hydrogels, including porosity enhancement, conductive filler incorporation, the salt-in-water strategy, and network structure modulation. Finally, it elaborates on the applications of DN hydrogels in flexible devices (supercapacitors, temperature sensors, zinc-air batteries). Based on the aforementioned findings, an innovative and feasible strategic outlook is put forward, with the aim of facilitating the further advancement of these flexible devices.