Preparation method of lithium ion battery high-nickel positive electrode material slurry

Abstract

The invention discloses a preparation method of a lithium ion battery high-nickel positive electrode material slurry, and relates to lithium ion batteries. The preparation method comprises the steps: 1) adding an adhesive in a solvent, stirring, after dissolving, adding acetone, stirring, then adding an additive after the solution is swelled, stirring, carrying out vacuum deaeration, and thus obtaining a mixed adhesive solution with the additive and the adhesive; 2) adding a positive electrode active material and a conductive agent to the mixed adhesive solution obtained in the step 1), stirring for 0.5-1 h at the speed of 600-900 r / min, after preliminary pre-mixing of the slurry, stirring for 6-7 h at the stirring speed of 2000-3000 r / min to obtain a battery slurry, filtering, and thus obtaining the lithium ion battery high-nickel positive electrode material slurry. The prepared high-nickel positive electrode material slurry has no gel-forming phenomenon and has good slurry liquidity; and the material processability is extremely superior during production of a lithium ion battery positive electrode piece, and the battery has good electrochemical performance after the slurry is made into the battery.

Description

technical field [0001] The invention relates to a lithium ion battery, in particular to a preparation method of a high nickel-based positive electrode material slurry for a lithium ion battery. Background technique [0002] Due to the important advantages of high voltage and high capacity, long cycle life and good safety performance, lithium-ion batteries have broad application prospects in portable electronic equipment, electric vehicles, space technology, defense industry, etc. The development of portable electronics and electric vehicles requires batteries to have higher energy density. How to increase the energy density of batteries, the key technology is to increase the energy of positive and negative active materials in lithium-ion batteries; currently, the capacity of negative electrode materials in lithium-ion batteries is much higher than that of positive electrodes. Therefore, the improvement of the energy density of lithium-ion batteries mainly depends on the posi...

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Problems solved by technology

[0002] Due to the important advantages of high voltage and high capacity, long cycle life and good safety performance, lithium-ion batteries have broad application prospects in portable electronic equipment, electric vehicles, space technology, defense industry, etc. The development of portable electronics and electric vehicles requires batteries to have higher energy density. How to increase the energy density of batteries, the key technology is to increase the energy of positive and negative active materials in lithium-ion batteries; currently, the capacity of negative electrode materials in lithium-ion batteries is much higher than that of positive electrodes. Therefore, the improvement of the energy density of lithium-ion batteries mainly depends on the positive electrode material; improving the energy density of the positive electrode material: one is to increase the gram specific capacity of the positive electrode material, and the other is to increase the potential of the positive electrode material, but increasing the voltage of the positive electrode material means High-voltage electrolyte is required, but the current high-voltage electrolyte technology is not mature enough, so increasing the specific capacity of the positive electrode material is an important direction for future material development; the current high-nickel-based materials (811 series, NCA) The capacity reaches more than 200mAh / g (button battery), but there is a disadvantage of high-nickel-based materials. As the NI content of the material increases, the Li dissolution of the material will increase, and the pH value of the material will be high. High-pH materials are easy to Absorb water, gel or even jelly will appear in the battery slurry during the pulping and coating process, making it impossible to coat and make batteries

Chinese patent CN104752683A discloses a method for the positive electrode of a water-based binder lithium ion battery, wherein the binder is a mixture containing 3 different structural unit copolymers, although the binder plays a role in strengthening the bond between the slurry and the matrix Strength, but it cannot solve the problem of slurry jelly caused by slurry water absorption due to high pH value of high nickel-based materials

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