Method for evaluating electrolyte resistance of aluminum-plastic composite film

Abstract

The invention provides a method for evaluating electrolyte resistance of an aluminum-plastic composite film. The method comprises the steps of (1) providing an aluminum-plastic composite film, and carrying out deep drawing to form an accommodating space; (2) preparing a bag body; (3) sealing a first side edge, positioning positive and negative tabs on the top edge, sealing the edge, adding electrolyte into the bag body, and sealing the edge of a second side edge to obtain a test product; (4) testing the side resistance by adopting a universal meter, and if the display data of the universal meter is 0.L, carrying out the next step; if the universal meter displays specific data, remanufacturing the test product; (5) putting the test product into an oven for baking, testing the side resistance by adopting the universal meter, and if the display data of the universal meter is 0.L, determining that the sample passes the test; and if the universal meter displays specific data, determining that the sample does not pass the test. According to the evaluation method, the battery packaging process can be simulated in the production and manufacturing stage of the aluminum-plastic composite film, the electrolyte resistance of the aluminum-plastic composite film for the battery is pre-judged in advance, and the electrolyte resistance of the aluminum-plastic composite film is rapidly, truly,conveniently and economically evaluated.

Description

technical field [0001] The invention relates to the technical field of performance evaluation of aluminum-plastic composite films, in particular to a method for evaluating the electrolyte-resistant performance of aluminum-plastic composite films. Background technique [0002] Aluminum-plastic composite film is one of the five major materials for lithium-ion batteries, and it is the packaging material for soft-pack lithium batteries. The aluminum-plastic composite film is composed of outer nylon layer / adhesive / intermediate aluminum foil / (adhesive, dry process) / inner heat-sealing layer, consisting of four to five layers in total, and each layer has relatively high functional requirements. The barrier ability, puncture resistance, electrolyte stability, high temperature resistance and insulation of aluminum-plastic composite film affect the performance of lithium-ion batteries. The lack of any one aspect may cause the performance of the battery to decline and be directly scrap...

AI Technical Summary

Problems solved by technology

The lack of any one aspect may cause the performance of the battery to decline and be scrapped directly

At present, most of the testing methods or evaluation methods for the electrolyte resistance performance of aluminum-plastic composite films adopt the soaking method (such as Chinese patent patent CN 108613919A), but this method is only to simply examine the adhesion between CPP and aluminum foil. The effective corrosion-resistant layer on the surface of the composite film is very thin, and the aluminum foil and the corrosion-resistant layer are stretched synchronously during drawing. It will directly affect whether the aluminum-plastic composite film is used for battery leakage, corrosion, etc.

However, the existing evaluation methods are not sure whether the aluminum foil and the corrosion-resistant layer still have the same electrolyte resistance after being drawn deep, and whether the aluminum foil and the corrosion-resistant layer are thinned, and whether the sealing and insulation properties after packaging are infiltrated with electrolyte. determination

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