Bab-type block copolymer and preparation method therefor, positive electrode plate, secondary battery, battery module, battery pack and power consuming device

A method for preparing a BAB-type block copolymer, comprising:

• preparation of B-block:
• polymerizing at least one monomer represented by formula V to prepare the B-block,
• wherein R′1, R′2 and R′3 are each independently selected from one or more of hydrogen, fluorine, and C1-3 alkyl containing at least one fluorine atom;
• preparation of A-block:
• polymerizing at least one monomer represented by formula VI to prepare the A-block, or subjecting a monomer represented by formula VII to ring-opening polymerization to prepare the A-block,
• wherein R′4, R′s and R′6 are each independently selected from hydrogen and substituted or unsubstituted C1-5 alkyl, and R′7 is selected from one of carboxyl, an ester group, hydroxyl, amido, cyano, and a substituted or unsubstituted aromatic group;
• and
• preparation of BAB-type block copolymer:
• connecting the B-blocks with the A-block to prepare the BAB-type block copolymer.

A positive electrode plate, comprising:

• a positive electrode current collector;
• and
• a positive electrode film layer provided on at least one surface of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material, a conductive agent, and a binder, and the binder comprises a BAB-type block copolymer;
• wherein the B-block contains a structural unit represented by formula I, and the A-block contains one or more of a structural unit represented by formula II and a structural unit represented by formula III,
• wherein R1, R2 and R3 are each independently selected from one or more of hydrogen, fluorine, and C1-3 alkyl containing at least one fluorine atom, R4, R5 and R6 are each independently selected from hydrogen and substituted or unsubstituted C1-5 alkyl, and R7 is selected from carboxyl, an ester group, hydroxyl, amido, cyano, and a substituted or unsubstituted aromatic group.