Dry Homogenization Process of Lithium Iron Phosphate Start-Stop Battery Cathode Slurry and Prepared Slurry

Abstract

A dry homogenization process for positive electrode slurry of lithium iron phosphate start-stop battery and the prepared slurry, including: S1) putting the dry powder into the mixing tank, and controlling the temperature during the stirring process; S2) wetting stage: mixing to step S1) Add conductive paste to the dry powder, put the conductive paste in 4-6 times; S3) kneading stage: after the last feeding of the conductive paste, add solvent to adjust the solid content of the paste in the mixing tank to 66%-68% Carry out kneading, and gradually increase the revolution speed and dispersion speed; S4) The solvent is added to the mixing tank at one time, and the stirring is continued. The invention improves the particle agglomeration of the slurry and reduces the fineness of the slurry; the slurry kneaded under the condition of high solid content is beneficial to disperse the material evenly under the action of high shear force, so that the high-rate battery can be charged and discharged More uniform, thereby greatly improving the rate charge and discharge performance and service life of the battery. In addition, the invention shortens the homogenization cycle to 4.5-5.5h.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a dry homogenization process for positive electrode slurry of lithium iron phosphate start-stop batteries. Background technique [0002] Although lithium batteries have defects such as cost, grouping, and safety performance in the field of starting batteries, as the start-stop technology has gradually become popular, lithium start-stop batteries are an important component of automobiles, and lithium iron phosphate system start-stop batteries are becoming more and more popular in light weight, It has outstanding advantages in service life, charging and discharging, and safety performance. [0003] As the first process of lithium battery manufacturing, the pulping process of battery positive electrode slurry is the top priority of the entire lithium battery manufacturing process. In the case of using a conventional mixer and ensuring the amount of feeding, the current dr...

AI Technical Summary

Problems solved by technology

In the case of using a conventional mixer and ensuring the amount of feeding, the current dry pulping process of lithium iron phosphate cathode slurry has the following problems in the manufacturing process: 1. Kneading with high solid content causes scratches between the stirring paddle and the cylinder wall; 2. Low solid content Content kneading causes uneven dispersion of materials, many particles, and cannot be coated in the subsequent process; 3. Low solid content kneading takes a long time and the effect is not good, resulting in prolonged stirring time in the high-speed dispersion stage

The above problems will lead to the following results: 1. Metal impurities are introduced into the slurry, which affects the safety performance of the battery; 2. The material is not uniformly dispersed, and particle agglomeration will affect the coating production efficiency, and in severe cases, affect the charge and discharge performance of the battery rate; 3. Stirring Long time seriously affects production efficiency and increases manufacturing cost