All-in-One Stretchable Flexible Zinc-Air Battery Enabled by Eutectogel-Derived Electrolyte and Electrodes.

Flexible zinc-air batteries (FZABs) draw attention for flexibility and high energy density, yet developing integrated ones with stable electrode/electrolyte interfaces and stretchability remains challenging. Herein, lactic acid/ethylene glycol-polyvinyl alcohol (LA/EG-PVA) eutectogel is rationally designed to simultaneously act as the electrolyte, zinc anode, and catalyst cathode matrix for the fabricating fully stretchable, self-healing, all-in-one FZABs. The carboxyl (─COOH) and hydroxyl (─OH) groups of LA form numerous hydrogen bonds with EG and PVA, creating a dense cross-linked structure in the eutectogel. This gives the eutectogel excellent adhesion for robust electrode/electrolyte contact and significantly enhances its liquid retention and ionic conductivity. Furthermore, the ─COOH and ─OH in LA molecules effectively immobilize water molecules via forming hydrogen bonds, which mitigates hydrogen evolution and corrosion side reactions. Simultaneously, the strong electrostatic interaction between LA and Zn(OH)4 2- induces uniform zinc deposition, thereby suppressing dendritic growth and passivation. The all-in-one FZAB with eutectogel-derived electrolyte/electrodes delivers a peak power density of 65.4 mW cm-2, retains 44.5 mW cm-2 under 100% tensile strain, self-heals to function under stretching after cutting, and operates from -40 to 100°C. This integrated eutectogel design approach offers a new avenue for stretchable FZABs and holds promise for more stretchable energy storage devices.