Baking process for lithium ion battery electrode plate containing water-based binding agent

Abstract

The invention discloses a baking process for a lithium ion battery electrode plate containing a water-based binding agent. The baking process comprises the following steps of (1) drying the electrode plate coated with paste for 1-2 hours under a vacuum condition and at a temperature of 100-110 DEG C; (2) reducing a temperature of the electrode plate in the step (1) to a room temperature and then drying the electrode plate for 15-30 minutes; and (3) drying the electrode plate in the step (2) for 3-4 hours at a temperature of 80-90 DEG C. The drying process of the electrode plate is optimized and improved, three steps of high-temperature rapid drying, room-temperature drying and low-temperature permanent drying are employed, the process is simple in step and high in maneuverability, so that the drying time is greatly reduced, and drying is thorough; and the electrode plate is not liable to crack or powder is not liable to fall off during the drying process, and the electrochemical performance of the battery is favorably improved.

Description

technical field [0001] The invention relates to the technical field of production of lithium-ion batteries, in particular to a baking process for electrode sheets of lithium-ion batteries containing an aqueous binder. Background technique [0002] The main function of the binder is to bind the active material particles and adhere the active material to the current collector. Lithium-ion battery binders can be divided into water-based binders and oil-based binders according to the solvent used. Water-based adhesives use water as a solvent, while oil-based adhesives generally use N-methylpyrrolidone as a solvent. Compared with oil-based adhesives, water-based adhesives have the advantages of low cost, non-toxicity, and environmental protection. At present, the mature negative electrode water-based binder products on the market are mainly SBR (styrene-butadiene rubber) and LAl32, both of which are polymer materials, and the molecular chain segments contain a large number of p...

AI Technical Summary

Problems solved by technology

However, during the drying and water removal process of the cell, the binder is heated, which may cause crosslinking of the crosslinkable group, thereby reducing the performance of the electrode, or insufficient drying, leaving more moisture

[0004] The current drying method usually uses constant temperature for constant temperature drying. The temperature of constant temperature drying is too low, and the drying efficiency is slow. It usually needs to be dried for more than 24 hours. The drying temperature is high, and the outer surface of the pole piece hardens quickly, which is easy to cause cracking or powder loss of the pole piece. At the same time, the moisture inside the pole piece is not easy to transfer to the outside, and the drying is not complete, resulting in residual moisture