▎ 摘　　要

NOVELTY - Adhesive comprises modified polyethyleneimine comprising a combination of dopaic acid and/or unsaturated hydroxy fatty acid. USE - The adhesive is used in a lithium ion battery negative electrode material (claimed). ADVANTAGE - The adhesive has excellent flexibility and strong bonding ability with silicon, has improved drying rate, crack resistance, rate performance and cycle performance of the pole piece. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for preparing the adhesive comprising (a) method A or method B, where the method (A) involves reacting polyethyleneimine, dobaic acid, and unsaturated hydroxy fatty acid to obtain the binder, and the method B involves (i) reacting polyethyleneimine with dopaic acid to obtain dopaic acid-modified polyethyleneimine, (ii) reacting the dopaic acid-modified polyethyleneimine obtained in step (i) with unsaturated hydroxy fatty acid to obtain the binder; and (2) a lithium ion battery negative electrode material comprises a negative electrode active material, a conductive agent, and the adhesive, the negative active material is a silicon-based active material, 94-98 %mass negative electrode active material, and 1-5 %mass conductive agent, 0.5-1.5 %mass negative electrode material, the silicon-based active material comprises at least two of elemental silicon, silicon alloy, silicon-carbon compound, or silicon-oxygen compound, and the conductive comprises acetylene black, Ketjen black, carbon fiber, superconducting carbon black, carbon nanotube, and graphene.