Direct forming production method for lithium ion battery cathode

Abstract

The invention relates to a direct forming production method for a lithium ion battery cathode. The method comprises the following steps of: 1) mixing 30 to 70 percent of lithium ion battery cathode active substance, 10 to 50 percent of conductive fiber and 1 to 20 percent of adhesive in percentage by mass in a reaction kettle respectively, wherein the temperature is controlled between 20 and 50 DEG C, the stirring speed is 60 to 300 revolutions per minute and the mixing is performed for 1 to 10 hours; and 2) pressing the mixture in a piece press to obtain an integrally formed lithium ion battery cathode pole piece, wherein the temperature is controlled between 70 and 120 DEG C and the pressure is 50 to 200MPa. The method has simple process; compared with the pole piece produced by a traditional method, the pole piece has the advantages of good forming property, low density and small volume; and the method can greatly reduce the weight and the volume of the pole piece. The method for producing the electrode pole piece can effectively reduce the thickness of the pole piece so as to improve the diffusion coefficient of lithium ions in the cathode and improve the electric capacity of a battery; and the active substance is uniformly contacted with the adhesive and organic electrolyte to prepare a high-density electrode so as to reduce the electrode area of side reaction in the charging / discharging process, prolong the service life of the battery and improve the stability of the battery.

Description

technical field [0001] The invention relates to a production method for direct forming of a negative electrode of a lithium-ion battery, in particular to a production method for an integrally formed pole piece which is different from the traditional method of coating a negative electrode active material on a current collector material. Background technique [0002] Due to the advantages of small size and high energy density, lithium-ion batteries are widely used in electronic products such as mobile communication equipment, digital cameras, and notebook computers. [0003] The battery cell of a lithium-ion battery is mainly composed of a positive electrode, a negative electrode, a separator, and an electrolyte. The performance of the negative electrode has the greatest impact on the performance of the lithium-ion battery. The volume of the negative active material will expand when intercalating and deintercalating lithium. [0004] Common lithium-ion battery negative electro...

AI Technical Summary

Problems solved by technology

[0005] This traditional method of coating the active material on the current collector has some insurmountable shortcomings, such as uneven coating, easy fall off of the active material, large thickness of the electrode sheet, etc. After the battery is assembled, these shortcomings will affect the battery. The charging and discharging performance of the battery will reduce the capacity and cycle life, and there will be hidden dangers in the safety performance of the battery.