Binder and lithium ion battery using the binder

The invention provides a binder and a lithium ion battery using the binder. The binder comprises at least one kind of a benzimidazole polymer grafted polyacrylic acid, and the mass percentage content of the polyacrylic acid in the benzimidazole polymer grafted polyacrylic acid is greater than 80 wt%. According to the benzimidazole polymer grafted polyacrylic acid, a benzimidazole polymer is grafted to the polyacrylic acid through a chemical bond (imidazole ring) so that the interaction force between the two is improved, and the mechanical property and the bonding strength of the binder are improved; and meanwhile, the problem of poor long-term cycling stability caused by mixing of the polyacrylic acid and the benzimidazole polymer is solved. 本发明提供一种粘结剂和使用该粘结剂的锂离子电池。所述粘结剂包括至少一种苯并咪唑类聚合物接枝的聚丙烯酸，所述苯并咪唑类聚合物接枝的聚丙烯酸中聚丙烯酸的质量百分含量大于80wt％。所述苯并咪唑类聚合物接枝的聚丙烯酸是将苯并咪唑类聚合物通过化学键(咪唑环)接枝到聚丙烯酸上，以提高两者之间的相互作用力，从而提高粘结剂的机械性能和粘结强度，同时解决聚丙烯酸与苯并咪唑类聚合物因混合而引起的长期循环稳定性差的问题。