申请人:Denka Company Limited
公开号:EP3922653A1
公开(公告)日:2021-12-15
A composition serving as a binder with well-balanced peel strength, high-rate discharge capacity retention ratio, and penetration resistance, a slurry for positive electrode, and a secondary battery using the composition is provided.
According to the present invention, a composition containing a graft copolymer is provided. The graft copolymer has a stem polymer and a plurality of branch polymers, the stem polymer has a polyvinyl alcohol structure, each of a first monomer unit and a second monomer unit is included in at least one of the plurality of branch polymers, the second monomer unit is different from the first monomer unit, when a content of the polyvinyl alcohol structure in the composition is CPVA% by mass and a total content of the first monomer unit and the second monomer unit in the composition is CM% by mass, the ratio of the content of the polyvinyl alcohol structure to the total content of the first monomer unit and the second monomer unit (CPVA/(CM+CPVA)) is 0.05 to 0.7, and the composition has a swelling degree of 200 to 900% with respect to propylene carbonate.
本发明提供了一种可用作粘合剂的组合物,该组合物具有均衡的剥离强度、高倍率放电容量保持率和抗穿透性,还提供了一种用于正极的浆料和一种使用该组合物的二次电池。
根据本发明,提供了一种含有接枝共聚物的组合物。该接枝共聚物具有干聚合物和多个支聚合物,干聚合物具有聚乙烯醇结构,多个支聚合物中至少有一个包含第一单体单元和第二单体单元,第二单体单元与第一单体单元不同、当组合物中聚乙烯醇结构的含量为 CPVA%(质量百分比),且组合物中第一单体单元和第二单体单元的总含量为 CM%(质量百分比)时,聚乙烯醇结构的含量与第一单体单元和第二单体单元的总含量之比(CPVA/(CM+CPVA))为 0.05 至 0.7,相对于碳酸丙烯酯,该组合物的溶胀度为 200 至 900%。