▎ 摘　　要

NOVELTY - Multifunctional aqueous binder is prepared by a mixture of sodium ion water-soluble polymer and polyethylene oxide, where the binder has a network structure formed by carboxyl groups and ester groups. USE - Multifunctional aqueous binder for use in electrode sheet of sodium ion battery (all claimed). ADVANTAGE - The aqueous binder has strong mechanical properties, bonding performance, improved cycle stability of the electrode. The sodium ion-containing water-soluble polymer in the binder can uniformly cover the surface of the active material to form a passivation film, reduce the loss of irreversible capacity of the battery, and improve the first coulombic efficiency and rate performance of the battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a sodium ion battery electrode sheet, which comprises a current collector and a coating layer coated on the current collector, where the coating layer includes an active material, a conductive agent, and multifunctional aqueous adhesives; (2) a method for preparing sodium ion battery electrode sheet, which involves mixing the multifunctional water-based binder for sodium ion batteries and active materials to obtain a slurry, and coating slurry on the current collector to obtain a coating, and sequentially press-drying and vacuum-drying the coating to obtain a sodium ion battery electrode sheet, where the vacuum drying temperature is 80-120 degrees C, preferably 100 degrees C; and (3) a sodium ion battery, which comprises a positive electrode, a negative electrode, an electrolyte and a separator, where the positive electrode and/or the negative electrode are the electrode sheet of the sodium ion battery.