Structure and method capable of preventing side bulging of negative pole piece of lithium battery during drying

Abstract

The invention provides a structure and a method capable of preventing side bulging of a negative pole piece of a lithium battery during drying, and belongs to the field of processing of the lithium battery. The structure comprises a drying oven; humidifying devices, an on-line thickness detection device, infrared induction devices, humidity induction devices and an deionized water atomizing deviceare arranged in the drying oven; the humidifying devices are symmetrically arranged on the left side and the right side of the drying oven; the on-line thickness detection device is vertically arranged over the negative pole piece; the infrared induction devices are vertically arranged on the edges of the two sides of the negative pole piece; and the humidity induction devices are arranged on theedges of the two sides of the negative pole piece. According to the structure and the method, the side bulging or side shrinking phenomenon in the drying process of the negative pole piece at the coating stage can be avoided, the local overpressure phenomenon during rolling is avoided, the low capacity and lithium separation risks of the battery can be effectively reduced, the manufacturing optimal rate of the battery is increased and the manufacturing cost of the battery is reduced.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, and relates to processing equipment and methods for designing lithium batteries, in particular to a structure and a method for preventing lithium battery negative electrodes from bulging during drying. Background technique [0002] As an important energy storage device in the field of electric vehicles and energy storage in the future, lithium-ion batteries have received strong support from governments and capital markets in recent years. Lithium battery projects have sprung up like mushrooms after rain, and the scale and speed of construction have achieved unprecedented development. In the preparation process of lithium batteries, the negative electrode material needs to be prepared into a slurry and then coated on the copper foil. During the coating process, the wet film needs to be dried in an oven. During the drying process, the edge of the coating is due to gas The liquid contact area is...

AI Technical Summary

Problems solved by technology

[0003] During the coating of the negative pole piece used in the power soft pack lithium-ion secondary battery currently on the market, during the drying process of the wet film pole piece, the drying speed of the non-edge area of ​​the pole piece is slower than that of the edge area, which will cause The semi-dry slurry coating in the edge area has a slight displacement towards the middle of the pole piece, resulting in the thickness of the edge area of ​​the pole piece being greater than that of the non-edge area of ​​the pole piece, resulting in a change in the coating surface density of the negative pole piece. At the same time, the edge of the pole piece Regional and large-thick pole pieces are prone to overvoltage and bright edges during rolling, which leads to the failure of the negative electrode performance in this area, resulting in abnormal conditions such as low battery capacity and lithium precipitation at the negative electrode that affect battery function and safety. occur

Images