▎ 摘　　要

NOVELTY - Block type polyamic acid solution, is claimed. The block-type polyamic acid in the block-type polyamic acid solution is composed of rigid polyamic acid segment and flexible polyamic acid segment in block form. The molar ratio of the rigid polyamic acid segment to the flexible polyamic acid segment is 0.05-20:1. The solid content of the polyamic acid solution is 0.5-40 wt.%. The intrinsic viscosity of the polyamic acid solution is 0.5-6 dl/g. USE - The block type polyamic acid solution is useful in preparing block type polyimide adhesive for lithium-ion battery pole piece (all claimed). ADVANTAGE - The block type polyimide adhesive has stronger cohesive force, strong interaction between the electrode material components, better adhesion performance and coating performance, more uniform slurry dispersion; and ensures lithium-ion battery assembled with lithium-ion battery pole piece has high discharge specific capacity, capacity retention rate and better high temperature safety performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparing block type polyamic acid solution, comprising (1) performing polycondensation reaction of rigid dibasic acid anhydride and rigid dibasic amine in polar solvent to obtain rigid polyamic acid precursor, and (2) performing polycondensation of flexible dibasic acid anhydride and flexible dibasic amine in polar solvent to obtain flexible polyamic acid precursor, and (3) continuing the polycondensation reaction of the rigid polyamic acid precursor obtained in step (1) and the flexible polyamic acid precursor obtained in step (2) to obtain final product. In step (1), the rigid polyamic acid precursor comprises an anhydride-terminated rigid polyamic acid precursor and/or an amine-terminated rigid polyamic acid precursor. In step (2), the flexible polyamic acid precursor includes an anhydride-terminated flexible polyamic acid precursor and/or an amine-terminated flexible polyamic acid precursor. In step (3), the flexible polyamic acid precursor at least comprises amine-terminated flexible polyamic acid precursor when the rigid polyamic acid precursor is anhydride-terminated rigid polyamic acid precursor; the flexible polyamic acid precursor at least comprises the anhydride-terminated flexible polyamic acid precursor when the rigid polyamic acid precursor is the amine-terminated rigid polyamic acid precursor; or the flexible polyamic acid precursor includes the amine-terminated flexible polyamic acid precursor and/or the anhydride-terminated flexible polyamic acid precursor when the rigid polyamic acid precursor comprises the anhydride-terminated rigid polyamic acid precursor and the amine-terminated rigid polyamic acid precursor; preparation of block type polyimide adhesive, comprising (i) preparing the block type polyamic acid solution, (ii) fully mixing and stirring the anode active material or the cathode active material, the block-type polyamic acid solution, conductive agent and polar solvent to obtain electrode slurry, and (iii) uniformly coating the electrode slurry on a current collector, drying and rolling, and finally performing heat treatment to obtain block-type polyimide binder on lithium-ion battery pole piece; block type polyimide adhesive prepared by above method; and block type polyimide adhesive containing lithium-ion battery pole piece, comprising a active material layer and a current collector. The active material layer is composed of anode active material or cathode active material, conductive agent and block type polyimide binder; and the active material layer comprises 80-99 wt.% anode or cathode active material, 0.5-10 wt.% conductive agent, and 1-10 wt.% block type polyimide adhesive.