Composite expansion adhesive tape for lithium battery and preparation method of composite expansion adhesive tape

Abstract

The invention discloses a composite expansion adhesive tape for a lithium battery and a preparation method thereof.The composite expansion adhesive tape comprises a macromolecule base film layer and an acrylic acid adhesive layer, the prepared macromolecule base film layer selects two kinds of modified polyurethane colloidal particles as an'elastomer base material 'of the expansion adhesive tape, the modified polyurethane colloidal particles are hydrophilic polymers, and the acrylic acid adhesive layer is a hydrophilic polymer; after meeting electrolyte, the polymer can absorb the electrolyte and expand by several times in volume to form a gelatinous sealing body, so that moisture permeation can be effectively prevented; due to the unique'hardness and softness' molecular structure, the elasticity and mechanical strength of the polyurethane adhesive particles can be regulated and controlled by controlling the proportion of hard segments to soft segments of the polyurethane adhesive particles, so that the elasticity, flexibility and active swelling capacity required by the expansion adhesive tape are provided. According to the prepared acrylic acid adhesive layer, by improving the variety and content of monomers in the main adhesive, the electrolyte resistance of the adhesive layer is excellent, and the long-term reliability of the adhesive tape is guaranteed.

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