Tough, Anti-Fatigue, Self-Adhesive, and Anti-Freezing Hydrogel Electrolytes for Dendrite-Free Flexible Zinc Ion Batteries and Strain Sensors

Quasi-solid aqueous zinc ion batteries (AZIBs) based on flexible hydrogel electrolytes are promising substitutions of lithium-ion batteries owing to their intrinsic safety, low cost, eco-friendliness and wearability. However, it remains a challenge to lower the freezing point without sacrificing the fundamental advantages of hydrogel electrolytes such as conductivity and mechanical properties. Herein, an all-around hydrogel electrolyte is constructed through a convenient energy dissipation strategy via the rapid and reversible intramolecular/intermolecular ligand exchanges between Zn2+ and alterdentate ligands. The as-obtained hydrogel exhibits excellent mechanical properties, fatigue resistance, high Zn-ion conductivity (38.2 mS cm-1), good adhesion (19.1 kPa), and ultra-low freezing point (-97 degrees C). Due to the alterdentate ligands help to improve the zinc ion solvation structure and guide uniform Zn deposition, the Zn||Zn symmetric cells show stable plating/stripping behavior and long-term cycle stability. The Zn||V2O5 full cells exhibit large capacity of 230.6 mAh g-1 and high capacity retention of 75.2% after 1000 cycles. Furthermore, flexible AZIBs operate stably even under extreme conditions including low temperature (-40 degrees C) and large bending angle (180 degrees). The mechanically damage-resistant hydrogel can also be utilized in flexible strain sensors. This work offers a facile strategy for developing mechanically deformation-resistant, dendrite-free, and environmentally adaptable AZIBs. A high-performance hydrogel electrolyte system for quasi-solid flexible aqueous zinc ion batteries (AZIBs) is achieved via intermolecular ligand exchange of highly dynamic [Zn(Al-Hbimcp)2]2+, thereby contributing to the improvement of zinc-ion solvation structure and promoting uniform Zn deposition. The as-prepared AZIBs operate stably even under extreme conditions including low temperature (-40 degrees C) and large bending angle (180 degrees). image