Aluminum-plastic film for packaging lithium battery and preparation method of aluminum-plastic film

Abstract

The invention discloses an aluminum-plastic film for lithium battery packaging, which comprises an outer nylon composite layer, a polyurethane bonding layer, an aluminum alloy foil layer, a polyolefin bonding layer and a polypropylene composite layer which are arranged in sequence, the polypropylene composite layer is a three-layer co-extrusion composite film, the middle layer of the co-extrusion composite film is ultra-high molecular weight polyethylene toughened polypropylene, and the middle layer of the co-extrusion composite film is an aluminum alloy foil layer. The outer layer is co-polypropylene filled with nano filler, and the inner layer is co-polypropylene. Due to the addition of the nano filler, the mechanical property of polypropylene can be improved, the effect of neutralizing hydrofluoric acid is achieved, the low-temperature heat sealing property of the inner-layer film can be improved, and the corrosion resistance of the aluminum-plastic film is improved. The invention further discloses a preparation method of the aluminum-plastic film, the inner layer film of the aluminum-plastic film is manufactured in a hot compounding mode, plasma cleaning treatment is conducted on the surface of the aluminum foil firstly, then plasma etching is conducted on the cleaned aluminum foil, the bonding performance between the aluminum foil and a bonding agent can be improved, and the service life of the aluminum-plastic film is prolonged. Therefore, the corrosion resistance and humidity and heat resistance of the aluminum-plastic film are improved.

Description

technical field [0001] The invention relates to the technical field of aluminum-plastic films, in particular to an aluminum-plastic film for lithium battery packaging and a preparation method thereof. Background technique [0002] With the development of soft-pack batteries and their popularity in mobile phones and new energy vehicles, the safety and energy density of soft-pack batteries have attracted the attention and attention of all parties. Compared with hard-shell cylindrical batteries and prismatic batteries, soft-pack batteries use aluminum-plastic film as packaging, and the gas generated by side reactions during battery charging and discharging will only make the soft-pack batteries bulge and will not explode. This makes the pouch battery have a greater advantage in terms of safety. On the other hand, due to the lighter weight of the aluminum foil, the energy density of the pouch battery is also higher, which can well meet the current battery life and other needs o...

AI Technical Summary

Problems solved by technology

The generation of strong acid dissolves the aluminum foil and invalidates the battery pack

Third, the heat sealing performance of polypropylene material is not very good, especially the low temperature heat sealing performance is poor, and the electrolyte inside the battery is easy to decompose at high temperature

Fourth, polypropylene is used as the inner layer material, and its puncture resistance needs to be further improved. The main reason is that lithium-ion battery cells use copper mesh and aluminum mesh as electrodes, and vacuum treatment is required when packaging and molding, while lithium-ion batteries When the package is folded back, the copper mesh and aluminum mesh may pierce the outermost material and short-circuit the battery

Images