Antifreezing Zwitterionic Hydrogel Electrolytes: Antifreezing Zwitterionic Hydrogel Electrolyte with High Conductivity of 12.6 mS cm−1 at −40 °C through Hydrated Lithium Ion Hopping Migration (Adv. Funct. Mater. 18/2021). (3rd May 2021)