▎ 摘　　要

NOVELTY - Preparing hydrogel comprises mixing polyelectrolyte SA with a negative charge and polyethylene PEI with a positive charge to obtain a mixed solution, introducing a cobalt ion into the mixed solution to obtain first network solution, mixing with acrylamide monomers, initiator and crosslinking agent to obtain second network solution, mixing the second-network solution with a methanol solution containing 2-methylimidazole ligand to obtain the final product. The conductive carbon Black comprises at least one of acetylene Black, Vulcan XC-72, Black pearls, carbon nanotubes and graphene powder. The water repellent comprises at least one of polytetrafluoroethylene, polyvinylidene fluoride and a copolymer of tetrafluoroethylene and ethylene. The dispersion includes at least one of ethanol, isopropanol and ethylene glycol. The substrate layer comprises carbon paper and/or carbon cloth USE - The hydrogel is useful in microporous layer slurry for preparing gas diffusion layer (all claimed). ADVANTAGE - The hydrogel: has excellent rebound resilience, high conductivity and self-repairing ability; can solve the problem of low intensity in the gas diffusion layer and bad battery performance caused by the damage or nick of the gas diffusion layer micro-pore layer. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for (1) a hydrogel prepared by the above mentioned method; and (2) a preparing the gas diffusion layer. DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart illustrating the method for preparing hydrogel (Drawing includes non-English language text).