Ultraviolet-Assisted Printing of Flexible Solid-State Zn-Ion Battery with a Heterostructure Electrolyte

Flexible solid-state Zn-ion batteries (ZIBs) have garnered considerable attention for next-generation power sources, but the corrosion, dendrite growth, and interfacial problems severely hinder their practical applications. Herein, a high-performance flexible solid-state ZIB with a unique heterostructure electrolyte is facilely fabricated through ultraviolet-assisted printing strategy. The solid polymer/hydrogel heterostructure matrix not only isolates water molecules and optimizes electric field distribution for dendrite-free anode, but also facilitates fast and in-depth Zn²⁺ transport in the cathode. The in situ ultraviolet-assisted printing creates cross-linked and well-bonded interfaces between the electrodes and the electrolyte, enabling low ionic transfer resistance and high mechanical stability. As a result, the heterostructure electrolyte based ZIB outperforms single-electrolyte based cells. It not only delivers a high capacity of 442.2 mAh g⁻¹ with long cycling life of 900 cycles at 2 A g⁻¹, but also maintains stable operation under mechanical bending and high-pressure compression in a wide temperature range (−20 °C to 100 °C).