the present application discloses a binder for a lithium ion battery , which comprises a polymer obtained through emulsion polymerization of a monomer in the presence of a reactive emulsifying agent . the binder is used in fabrication of a lithium ion electrode plate , whereby a thin film formed on the surface of an electrode membrane and fine channels formed in the electrode membrane with the use of a conventional emulsifying agent during the electrode membrane - forming process are eliminated , and the lithium ion conductivity of the electrode membrane is improved . meanwhile , with the use of the reactive emulsifying agent , the bonding effect of the binder and the stability of the electrode membrane are improved , thereby greatly improving the charging rate and cycle life of the lithium ion battery .