A kind of water-based PVDF slurry for lithium ion battery and its preparation and use method

Abstract

The invention discloses a water-based PVDF slurry for lithium-ion batteries and methods for preparing and using the same, aiming to provide a water-based PVDF slurry for lithium-ion batteries with good dispersion effect and low environmental pollution. The technical points are the The water-based PVDF slurry is calculated based on the total mass of 100%, and the mass percentage of each component is: PVDF powder 0.05%-20%, dispersant 0.1%-10%, wetting agent 0.2%-5%, and the balance is water; It belongs to the technical field of lithium batteries.

Description

technical field [0001] The invention relates to a slurry for lithium ion batteries, in particular to an aqueous PVDF slurry for lithium ion batteries, and belongs to the technical field of lithium batteries. Background technique [0002] At present, all positive electrodes of lithium-ion batteries use NMP organic solvent to dissolve PVDF or PVDF+HFP mixture, and then add conductive agent. The organic solvent PVDF is volatile and flammable, and has a strong odor, which is harmful to the health of employees. At the same time, NMP requires very expensive equipment to recycle, and consumes a lot of electric energy, which does not save energy and reduce costs. The invention replaces the organic solvent NMP with a water-based solvent, on the one hand, reduces temperature and energy consumption, and on the other hand, improves the operating environment of employees, and especially brings a great degree of improvement and improvement to the environmental impact assessment of lithiu...

AI Technical Summary

Problems solved by technology

However, it is difficult to disperse PVDF with PAA, CMC and water in this technical scheme, and it cannot be dispersed to a very uniform degree, and it is easy to agglomerate and delaminate, and it is also difficult to disperse positive active materials such as lithium cobaltate, lithium iron phosphate and three Yuan and other materials

And water-based glue such as CMC and PAA is used. If the positive electrode is the current high-voltage lithium cobalt oxide, especially the battery voltage is 4.35V, 4.4V or higher 4.5V, then the cathode is fully charged to lithium. The potential is as high as 4.7V, which is easy Oxidation and decomposition of water-based glue such as CMC will deteriorate the performance of the battery, especially for cycle and high-temperature storage, so the current CMC and SBR systems can only be used in the negative electrode system

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