Preparation method for double-layer PET protective film for lithium battery pack

Abstract

The invention provides a preparation method for a double-layer PET protective film for a lithium battery pack. The preparation method comprises the following steps: firstly, uniformly stirring and mixing acrylic pressure sensitive adhesive, ethyl acetate and butanone, then adding blue paste, white paste, yellow paste, a retarder and an assistant into the mixture in sequence, finally, adding hexamethylene diisocyanate and lithium tetrafluoroborate, and stirring uniformly to obtain an adhesive liquid; secondly, coating a single surface of a PET substrate with the adhesive liquid, performing heating treatment through 6 to 8 sections of baking channels in sequence until the residual solvent amount of the adhesive liquid does not exceed 0.5 parts; adhering the PET substrate which is coated with the adhesive liquid and a PET which is not coated with the adhesive liquid to obtain a double-layer PET composite film; coating the single surface of the PET composite film with the adhesive liquid, heating until the residual solvent amount of the adhesive liquid does not exceed 0.5 parts, discharging bubbles and winding at normal temperature. The PET protective film disclosed by the invention has high toughness, puncture resistance, high insulating property, high temperature resistance, and high adhesivity to an aluminum shell of a lithium battery, and has no residual adhesive after the PET protective film is peeled; the protection on the lithium battery pack when a new energy vehicle is driven is effectively realized.

Description

technical field [0001] The present invention relates to a PET protective film. More specifically, the present invention relates to a method for preparing a double-layer PET protective film for a lithium battery pack. Background technique [0002] In order to solve the increasingly serious energy and environmental problems, more and more countries around the world pay attention to energy conservation and emission reduction. For the environmental pollution caused by automobiles, the best solution at present is to vigorously develop new energy vehicles, especially electric vehicles. Therefore, as a key component of new energy vehicles, lithium battery packs are being widely used with the popularization of new energy vehicles, and their power supply performance, stability and safety are one of the factors that determine the further development and market promotion of new energy vehicles. Key factor. [0003] New energy vehicles have the characteristics of high-speed movement, ...

AI Technical Summary

Problems solved by technology

[0003] New energy vehicles have the characteristics of high-speed movement, violent vibration, high-temperature work, and rapid charging and discharging when driving, resulting in potential dangers such as impact, stabbing, short connection, falling, water immersion, and fire when the power battery is in use. One-tenth of the non-safety rate will cause extremely serious consequences. Therefore, compared with traditional fuel vehicles, the flammability and explosion of battery packs make electric vehicles more vulnerable

At present, foreign developed countries mostly use high-strength composite materials such as carbon fiber to wrap and protect the battery pack, but this method is too costly, and the domestically produced lithium battery wrapping film is easy to scratch, low in flexibility, and poor in high temperature resistance. And other shortcomings, which limit the development of lithium battery enterprises in China

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