Negative electrode paste of battery and preparation method of negative electrode paste

Abstract

The invention relates to negative electrode paste of a battery. The negative electrode paste is prepared from components in parts by mass as follows: 30-60 parts of an active negative electrode material, 0.05-8 parts of a conductive additive, 0.1-9 parts of a binder, 35-65 parts of a solvent and 0.5-2 parts of perfluoroalkyl sulfonate, wherein the number of C atoms of a perfluoroalkyl sulfonate molecule is 4-16. Perfluoroalkyl sulfonate is an efficient surfactant, can account for as low as five permillage by mass of the whole paste, has quite stable chemical property and cannot affect performance of the battery. The negative electrode paste adopting the formula is good in uniformity, cracking is avoided after solvent evaporation, the yield of prepared negative electrodes of batteries is 95% or higher, the capacity is good, and 90% or more of initial capacity can be still kept after 100 times of circulation at the current density of 1C.

Description

technical field [0001] The invention belongs to the field of energy chemistry, and in particular relates to a battery negative electrode slurry and a preparation method thereof. Background technique [0002] In the slurry mixing process of lithium-ion battery negative electrode slurry, the traditional method often adopts to prepare the glue first, add the prepared glue into the double planetary mixer, and then add the negative electrode active material, conductive agent, etc. in turn. Stirring was carried out to make negative electrode slurry. The traditional process of pulping is cumbersome and requires premixing, strong mixing, inversion, defoaming, sieving and other processes. The pulping cycle is long, and a complete process often takes more than 4 hours. [0003] This traditional slurry preparation process not only has a long production cycle, but also has poor slurry stability. The prepared slurry has defects such as uneven dispersion, easy settlement, and poor finene...

AI Technical Summary

Problems solved by technology

The traditional pulping process is cumbersome and requires premixing, strong mixing, inversion, defoaming, sieving and other processes. The pulping cycle is long, and a complete process often takes more than 4 hours.

[0003] This traditional slurry preparation process not only has a long production cycle, but also has poor slurry stability. The prepared slurry has defects such as uneven dispersion, easy settlement, and poor fineness.

The negative electrode sheet prepared by coating the slurry prepared by the traditional process has defects such as "white spots", "black spots", "pits", and "bumps", which seriously affect the production efficiency and yield of the negative electrode sheet , further speaking, seriously affects the performance of the finished battery

[0004] CN104956525A discloses a slurry composition for lithium-ion battery electrodes, comprising electrode active materials, conductive materials, viscosity regulators, particulate binding materials, surfactants and water, capable of suppressing the generation of pinholes in aqueous slurries and end bulging, but the surfactant needs to be compounded with polyoxyethylene surfactant and sulfosuccinate or its salt, and the addition of surfactant is relatively large, which affects the conductivity of the electrode. is unfavorable

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