Detection method of aluminum plastic film for lithium ion battery

Abstract

The invention discloses a detection method of an aluminum plastic film for a lithium ion battery. The detection method comprises the following steps: (1) injecting a dilute sulphuric acid solution into an aluminum plastic film, extracting gas from the aluminum plastic film, and sealing the aluminum plastic film; and (2) putting the aluminum plastic film sealed in the step (1) into a drying oven, heating, unsealing the aluminum plastic film, and carrying out differentiation. The detection method has the beneficial effects that the sulphuric acid solution is injected into the aluminum plastic film, and the aluminum plastic film is sealed and heated, so that the detection method is simple, the detection cost is low, and the detection manner is flexible; and if the detection speed needs to beincreased, the concentration of the filled sulfuric acid solution can be increased, and the damaging position of the aluminum plastic film can be rapidly and accurately found out.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a detection method for aluminum-plastic films used in lithium-ion batteries. Background technique [0002] Among them, aluminum-plastic film, as one of the raw materials for soft-pack batteries, is a must-check item for battery factories. Aluminum plastic film usually consists of outer nylon layer, middle aluminum layer and inner PP layer. The outermost layer of nylon has the function of anti-wear, the middle aluminum layer plays the role of isolating air and moisture, and the inner PP layer plays the role of isolating electrolyte corrosion and fusion sealing. In the aluminum-plastic film production process, transportation process or mold punching process, it is easy to [0003] The PP layer of the aluminum-plastic film is damaged, so that the electrolyte and the aluminum layer are corroded by contact and lead to excessive internal resistance, battery gas, aluminum-pl...

AI Technical Summary

Problems solved by technology

In the aluminum-plastic film production process, transportation process or mold punching process, it is easy to

[0003] The PP layer of the aluminum-plastic film is damaged, so that the electrolyte and the aluminum layer are contacted and corroded, resulting in excessive internal resistance, battery gas, aluminum-plastic film delamination, and even rupture and leakage.

[0004] At present, there is no quick and effective method to detect whether the PP layer of the aluminum-plastic film is damaged. The aluminum-plastic film is observed through a scanning electron microscope. The aluminum-plastic film after shelling was compared with the light, and the visual observation was carried out, but the damage of some PP layers was relatively small and could not be recognized by the naked eye.