The method relates to a field for the production of lithium-ion batteries, which is to produce rapidly dissolving sodium carboxymethylcellulose used in battery pastes.
CMC(Carboxymethylcellulose sodium), white or milky white fibrous powder or granule, dispersed in water into clear gel. Lithium battery preparation process, often selected as the anode material of the adhesive, Suspending agent, thickener, lithium industry has become well known as one of the indispensable materials.
Most of thenegative electrode paste formulations of the lithium industry are as follows: Toner, conductive agent, CMC, styrene-butadiene rubber (SBR) and deionized water. Toners and conductive agents are difficult to dissolve in deionized water and are thus dispersed by CMC. CMC plays an important role in the dispersion of toner and conductive agents.
CMC dissolution is directly related to the dispersion effect of the entire slurry. After a large number of practical cases and experience show that, the slurry of the negative binder for the CMC and SBR system, particles problems often effect the CMC dispersion.
For the purpose of achieving the best dissolution effect, here provides a process for rapidly dissolving sodium carboxymethylcellulose which is intended to reduce the hygroscopicity of sodium carboxymethyl cellulose by the addition of N-methylpyrrolidone, thereby shortening the agitation time and enhance the dispersion effect, increasing the role of its suspending agent thickening, the steps are as follows:
A. Mix sodium carboxy methyl cellulose and N-methylpyrrolidone in mass ratio of 1: 2 to 4 and stir well to obtain mixed sodium carboxymethyl cellulose solution;
B. Add quantitative deionized water to the mixing tank of the mixer and slowly pour the sodium carboxymethyl cellulose solution prepared in step A while stirring the deionized water.
C. stirring in vacuum 20 ~ 40Hz conditions for 5 ~ 10min;
D. Clean the agitated paddle and the gelatinous sodium carboxymethyl cellulose adhered on the barrel wall and then stir for 30 min to 60 min under vacuum 20 to 40 Hz, to obtain a sufficiently dissolved sodium carboxymethyl cellulose solution.