Insights into Dendrite Regulation by Polymer Hydrogels for Aqueous Batteries

Aqueous batteries, renowned for their high capacity, safety, and low cost, have emerged as promising candidates for next-generation, sustainable energy storage. However, their large-scale application is hindered by challenges, such as dendrite formation and side reactions at the anode. Hydrogel electrolytes, which integrate the advantages of liquid and solid phases, exhibit superior ionic conductivity and interfacial compatibility, giving them potential to suppress dendrite evolution. This Perspective first briefly introduces the fundamentals underlying dendrite formation and the unique features of hydrogels. It then identifies the key role of water and polymer networks in inhibiting dendrite formation, highlighting their regulation of water activity, ion transport, and electrode kinetics. By elucidating the principles of hydrogels in dendrite suppression, this work aims to provide valuable insights to advance the implementation of aqueous batteries incorporating polymer hydrogels.