A positive electrode slurry for a lithium iron phosphate battery, a positive electrode sheet and a preparation method thereof

Abstract

The invention discloses a positive electrode slurry of a lithium iron phosphate battery, a positive electrode sheet and a preparation method thereof, wherein the positive electrode slurry of the lithium iron phosphate battery consists of the following components in parts by weight: 90-95 parts of positive electrode active materials, 4-6 parts of conductive agent, 5-7 parts of binder, 3-5 parts of dispersant, 2-4.2 parts of toughening agent and 80-90 parts of solvent; wherein the positive electrode active material is lithium iron phosphate, and the adhesive The binder is polyacrylic acid, the toughening agent is polymethyl methacrylate, and the weight ratio of polyacrylic acid and polymethyl methacrylate is 1:0.4-0.6. The invention can improve the flexibility of the pole piece, and the positive electrode slurry has good stability.

Description

technical field [0001] The invention relates to the field of lithium iron phosphate batteries, in particular to a positive electrode slurry, a positive electrode sheet and a preparation method of a lithium iron phosphate battery. Background technique [0002] The preparation of lithium iron phosphate cathode slurry mainly includes two homogenization methods: oily system and watery system. The oily system uses the organic solvent NMP (N-methylpyrrolidone) as the solvent. NMP has the disadvantages of high toxicity, high price, and difficult recovery. The homogenization technology of the water-based system uses deionized water as the solvent, and the production process is more environmentally friendly and the cost is lower. However, the traditional water-based slurry has poor fluidity, is not easy to disperse, and the electrode sheet is not flexible enough to be wound. It can only be laminated, and the production efficiency is low. In addition, there is a certain gap in electr...

AI Technical Summary

Problems solved by technology

[0006] Chinese patent document CN103943851A discloses a lithium iron phosphate water-based positive electrode slurry, which solves the problem that the solid matter in the prior art lithium iron phosphate water-based positive electrode slurry is not easy to uniformly disperse, and the consistency and stability of the aqueous positive electrode slurry are poor. It is composed of the following components in mass percentage: 45-50% of lithium iron phosphate, 2-3% of conductive agent, 2-3% of water-based binder, 3-5% of ethanol, and the balance for deionized water

[0007] The positive electrode sheet made of the positive electrode slurry of the current lithium iron phosphate battery still has the problem of flexibility