Barrier layer soft package film of polymer lithium ion battery

Abstract

The present invention provides a barrier layer soft package film of a polymer lithium ion battery. The barrier layer soft package film comprises a layer of aluminum foil, wherein both sides of the aluminum foil are coated with an adhesive layer, the aluminum foil at least comprises silicon (Si), iron (Fe), copper (Cu), manganese (Mn) and aluminum (Al), the Fe content is 0.9-1.5 wt%, a Fe / Si ratio is 10.0-1.67%. At least one surface of the inner surface and the outer surface of the aluminum foil is treated by corona. The surface of the adhesive external resistance layer is coated with a double-component polyurethane resin adhesive and a polyester polyol adhesive. In the prior art, when the Fe content in the aluminum foil is more than 0.9 wt%, the softness of the aluminum is damaged, the bag making performance of the laminate becomes poor; when the Fe / Si ratio in the industrial pure aluminum is more than 5%, the processing hardening rate is increased. With the present invention, the problems in the prior art are overcome. The experiment results show that: the formed barrier layer of the present invention has characteristics of tensile strength more than 80-98 Mpa, elongation more than 21%, a cupping test value more than or equal to 6.10, elongation at break more than or equal to 40 N and heat sealing strength more than or equal to 40 N; under the pressure of 25 (kpa), no leakage and no rupture are generated.

Description

technical field [0001] The invention relates to an intermediate layer soft packaging material in at least three layers of barrier layer soft packaging films for polymer lithium ion batteries. Background technique [0002] The polymer lithium-ion battery barrier layer soft coating is a solid anti-permeable material that blocks the intrusion of water and oxygen in the polymer lithium-ion battery outer barrier layer, and prevents the volatile solvent content of the battery electrolyte from penetrating. The barrier performance of the flexible packaging film of the barrier layer is mainly related to the aluminum foil barrier film and the adhesive. It is closely related to the bonding strength and plastic deformation ability between the aluminum foil of the barrier layer and the inner and outer layers, and the peel strength between the aluminum foil and the inner and outer layers directly affects the sealing performance of the battery. The synergistic combination of the adhesive ...

AI Technical Summary

Problems solved by technology

Experiments have proved that whether it is lamination with dry coating organic solvent adhesive, wet coating inorganic adhesive lamination, or hot melt coating lamination, the disadvantage of using the same adhesive layer on both sides is that it cannot Effective barrier to the penetration of battery contents

[0008] The chemical treatment takes a long time, and the treatment liquid is chemically aggressive; the effect of the photochemical treatment is not ideal, it takes a long time, and the cost is high

Aluminum foil is a conductor with poor dielectric properties, low resistance and excellent conductivity, and corona treatment is generally not applicable.