Method for manufacturing battery negative pole piece

Abstract

The invention discloses a method for manufacturing battery negative pole piece, including drying and rolling, which is characterized in that the sizing before drying and rolling is continuous sizing, and adopting one-sided sizing at the no-powdering part of the cathode pole piece contacted to the steel shell. Compared with the prior art, the invention has beneficial effects that the inventive method adopts using steel belt matrix to position at the center of the smear paste die clearance, performs powder scraping continuous operation before pole piece rolling, which is in favor of reducing alloy oxidation of pole piece in the production process and impurity introduction in the pole piece, and is in favor of improving the consistency of pole piece production quality and production efficiency of the pole piece.

Description

technical field [0001] The invention relates to battery production, in particular to a production method of a battery negative electrode sheet. Background technique [0002] Existing small-sized cylindrical Ni-MH batteries generally stack the positive electrode, the negative electrode, and the diaphragm between the positive and negative electrodes by winding, then wind the cylindrical electrode assembly into a cylindrical battery case, add electrolyte, The battery is sealed to complete the production. The battery safety valve is connected to the positive electrode as the positive terminal of the battery, and the steel shell of the battery contacts the outermost circle of the negative electrode as the negative terminal of the battery. The active material of the positive electrode is spherical nickel hydroxide, which is generally made of foamed nickel as the conductive matrix, which is pressed by slurry coating or dry powder infiltration; while the active material of the nega...

AI Technical Summary

Problems solved by technology

"Cylindrical Alkaline Storage Battery" announced by Chinese patent CN1297031C, "Cylindrical Alkaline Storage Battery" announced by CN1301564C, and "Alkaline Secondary Battery" announced by CN2570999Y respectively improve the utilization of the non-frontal part of the negative electrode of the battery facing the positive electrode. However, CN1297031C and CN1301564C did not propose how to realize that the amount of sizing is 75% to 100% of the total active material amount of the negative electrode in the corresponding part of the negative plate; and the alkaline secondary battery of CN2570999Y is applied to the scraping of Ni-MH steel strip When making the negative electrode sheet, there are the following problems:

After the negative electrode sheet is dried and rolled, the density of the electrode sheet is 6.0 ~ 6.5g / cm3. At this time, if the powder is scraped, the temperature of the electrode sheet will rise very high, and the alloy powder will be oxidized, which will affect the storage of the alloy powder. Hydrogen capacity, battery internal pressure, life and other comprehensive performance will be reduced

And when the temperature rise is not controlled, it may even cause the alloy powder to catch fire;

[0004] 2) When the steel strip matrix in the negative electrode sheet is not in the center of all the slurry, it is easy to scrape the steel strip, and it will also introduce impurities into the electrode sheet, and even cause the negative electrode sheet to be scrapped, even if the steel sheet is only scraped With the surface layer, it is also easy to damage the nickel-plated protective layer of the steel strip. The oxidation equilibrium potential of iron in alkaline solution is -0.877V. When the negative electrode has no electricity, the potential protection cannot be generated. Iron is easy to oxidize, which will affect the contact with the steel shell. electrical conductivity;

[0005] 3) The use of a single pole piece scraping powder will affect the consistency of the pole piece production quality and the production efficiency of the pole piece

Images