Lithium ion battery positive electrode slurry, preparation method thereof and stirring cylinder used in preparation process

Abstract

The invention relates to lithium ion battery positive electrode slurry, a preparation method thereof and a stirring cylinder used in the preparation process. The preparation method of the lithium ionbattery positive electrode slurry comprises the following step of adding a solvent in the process of adding active substance powder into a mixer; the solvent is added in a spraying manner; the activesubstance powder is continuously infiltrated and settled to the bottom of the mixer in the mixing process, so tht active substance powder floating or adhering to the inner wall of the mixer and the stirring paddle is reduced; meanwhile, infiltration of the active substance powder is enhanced, thick wet material layers are prevented from being formed on the inner wall of the mixer and the stirringpaddle, a problem that the proportion of the positive electrode slurry is unbalanced due to the formation of the wet material layers is solved; and the mixing uniformity of the positive electrode slurry is improved, the later discharging and net blocking frequency of the positive electrode slurry is reduced, and the preparation process is short in time consumption.

Description

Technical field [0001] The invention belongs to the field of lithium batteries, and relates to a lithium ion battery positive electrode slurry, a preparation method thereof, and a stirring cylinder used in the preparation process. Background technique [0002] The key to the development of new energy vehicles is its power source. Lithium-ion batteries have the advantages of high energy density, low self-discharge, no memory effect, wide operating voltage range, long service life, and no environmental pollution. They are currently the main power source for new energy vehicles. Among them, the performance of the positive electrode slurry has an important influence on the performance of the lithium ion battery. [0003] CN106129336A discloses a preparation method of lithium battery positive electrode slurry. The preparation method includes the following steps: (1) Adding a solvent to a reactor, sprinkling the dry product of binder A evenly on the surface of the solvent, and stirring ...

AI Technical Summary

Problems solved by technology

CN108767191A discloses a preparation method of lithium-ion battery cathode slurry, which includes the following steps: (1) using a planetary vacuum mixer to revolve at 20 ± 5rpm according to the ratio of anode active material, binder, first conductive agent and additive Stir at 1000±50rpm rotation speed and 1000±50rpm rotation speed for 10-25min, so that the temperature is controlled at 20-35°C; (2) After adding solvent according to the proportion, stir at 20±5rpm revolution speed and 1200±50rpm rotation speed for 60-100min; ( 3) After adding the second conductive agent according to the proportion, stir at 20±5rpm revolution speed and 1300±50rpm rotation speed for 100~140min, and carry out vacuum defoaming, the vacuum degree is -0.08~-0.1MPa; the above positive electrode slurry During the preparation process, there are powders that are easy to form a wet material layer on the inner wall of the mixing tank and the stirring paddle, which will easily cause the imbalance of the positive electrode slurry ratio

There are some disadvantages in this feeding sequence: First, after a large amount of solvent and powder are added to the 1500L mixing tank, the separation between the solvent and the powder is obvious, the powder floats on the upper layer of the solvent, and the upper layer of powder floats or sticks to the inner wall of the mixing tank And the upper layer of the stirring paddle, the stirring is insufficient; the second point, the insufficient stirring leads to the formation of a thicker wet material layer on the inner wall of the mixing tank and the upper layer of the stirring paddle, which requires manual scraping of the tank, and the outer wet material layer wraps the dry powder. Slurry discharge blocks the filter screen, which affects production efficiency; the third point is the feeding sequence one by one. It takes about 8 hours from feeding to discharging including feeding, which takes a long time and increases manufacturing costs.

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