BAB type block copolymer, preparation method, positive pole piece, secondary battery, battery module, battery pack and electric device

The invention provides a BAB type block copolymer, a preparation method, a positive pole piece, a secondary battery, a battery module, a battery pack and an electric device. The BAB type block copolymer comprises a B-block and an A-block, the B-block contains a structural unit shown in a formula I, the A-block contains one or more of a structural unit shown in a formula II and a structural unit shown in a formula III, R1, R2 and R3 are independently selected from one or more of hydrogen, fluorine and Cl-3 alkyl containing at least one fluorine atom, and R1, R2 and R3 are independently selected from one or more of hydrogen, fluorine and Cl-3 alkyl containing at least one fluorine atom. R4, R5 and R6 are independently selected from hydrogen and substituted or unsubstituted C1-5 alkyl, and R7 is selected from carboxyl, ester group, hydroxyl, acylamino, cyano and substituted or unsubstituted aryl.