Multiple healing flexible zinc-ion battery based on double cross-linked polyampholyte hydrogel electrolyte

Flexible and multifunctional zinc-ion batteries (ZIBs) play an important role in flexible and wearable electronics. However, traditional polyvinyl alcohol-based gel electrolytes have inherent limitations in terms of healability and stretchability, which cannot fully meet the requirements of flexible, healable, and multifunctional ZIBs. Herein, polyampholyte nanocomposite hydrogels are synthesized via in-situ co-polymerization of the anionic monomer sodium p-styrenesulfonate and the cationic monomer methacrylatoethyl trimethyl ammonium chloride in the presence of inorganic crosslinkers graphene oxide (GO) and Laponite. The hydrogels demonstrate high mechanical performance, excellent ionic conductivity (27.3 mS cm−1), and superior multiple healable performance due to the presence of inorganic crosslinkers such as Laponite and GO, as well as zwitterionic monomers. The as-prepared ZIBs based on polyampholyte hydrogel electrolyte are assembled using carbon nanotubes (CNTs)/vanadium disulfide as cathode and CNTs/Zn as anode. The resulting ZIBs possess excellent electrochemical properties (245 mAh g−1 at 0.05 A g−1) and multifunctional healability under ambient temperature, near infrared light with 808 nm and heating conditions, respectively. More significantly, the broken/healed ZIBs exhibit superior flexibility and six broken/healing cyclic stability. The polyampholyte nanocomposite hydrogel electrolytes extend the application of flexible energy storage devices to other portable and wearable energy related devices with multifunctionality.