Rolling method of lithium ion battery negative negative pole piece

Abstract

The invention discloses a rolling method of a lithium ion battery negative pole piece. The rolling method comprises the following steps of: drying a coated negative pole piece to obtain an initial negative pole piece; rolling the initial negative pole piece through a hot pressing roller to obtain a primary rolled negative pole piece; baking the primary rolled negative pole piece; and rolling the pole piece through a cold pressing roller, and directly rolling the pole piece to the target thickness so as to obtain the required negative pole piece. According to the rolling method of the lithium ion battery negative negative pole piece of the invention, the rebound of the negative pole piece can be effectively improved, the consistency of the surface density and thickness of the pole piece is improved, the deformation of a battery cell in the service life is prevented, the uniformity of the porosity of the pole piece is improved, the liquid absorption capacity of the pole piece is improved, and the electrochemical performance of a battery is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a rolling method for negative pole pieces of lithium-ion batteries. Background technique [0002] Lithium-ion batteries have been widely used in the 3C consumer market and the field of new energy vehicles because of their high energy density, high output voltage, long service life, no memory effect, and environmental protection. The preparation of lithium-ion batteries requires multiple processes, among which pole piece rolling is an essential process. The pole piece reaches a certain compaction density after rolling, which is very important for improving the energy density of lithium-ion batteries. At present, the positive pole piece can be rolled once, because it is easy to be brittle due to multiple rolling; while the negative electrode is generally rolled once, but there are also two rolling, which is easy to rebound in the later stage, resulting in...

AI Technical Summary

Problems solved by technology

At present, the positive pole piece can be rolled once, because it is easy to be brittle due to multiple rolling; while the negative electrode is generally rolled once, but there are also two rolling, which is easy to rebound in the later stage, resulting in deformation of the battery cell and increasing the thickness of the battery cell. ,Affect