1. Composition of the electrode:
1.1 Positive electrode composition:
 · Lithium cobaltate: positive electrode active material, lithium ion source, and lithium source for battery.
 · Conductive agent: Improve the conductivity of the positive electrode sheet and compensate for the electronic conduction of the positive electrode active material.
The liquid absorption of the electrolyte of the positive electrode sheet is increased, the reaction interface is increased, and the polarization is reduced.
 · PVDF adhesive: Bonds lithium cobalt oxide, conductive agent and aluminum foil or aluminum mesh together.
 · Positive lead: Made of aluminum foil or aluminum tape.
1.2 Negative electrode composition:
 · Graphite: The negative active material constitutes the main substance of the negative electrode reaction; it is mainly divided into natural graphite and artificial
There are two major types of graphite.
 · Conductive agent: Improve the conductivity of the negative electrode sheet and compensate for the electronic conduction of the negative electrode active material.
Improve reaction depth and utilization.
Prevent the generation of dendrites.
The liquid absorption capacity of the conductive material is utilized to increase the reaction interface and reduce polarization.
(Can be selected according to the graphite particle size distribution plus or not).
 · Additives: Reduce irreversible reactions, improve adhesion, increase slurry viscosity, and prevent slurry precipitation.
 · Water binder: Bond graphite, conductive agents, additives and copper foil or copper mesh together.
 · Negative lead: Made of copper foil or nickel tape.

2. Ingredients purpose:
The compounding process actually mixes the various components in the slurry together in a standard ratio to prepare a slurry to facilitate uniform coating and ensure uniformity of the pole pieces. The ingredients generally comprise five processes, namely: pretreatment, blending, wetting, dispersion and flocculation of the raw materials.

3. Principle of ingredients:
Positive dosing principle
3.1 Physical and chemical properties of raw materials.
 · Lithium cobaltate: non-polar material, irregular shape, particle size D50 is generally 6-8 μm, water content ≤ 0.2%, usually alkali, PH value is about 10-11.
Lithium manganate: non-polar material, irregular shape, particle size D50 is generally 5-7 μm, water content ≤ 0.2%, usually weak base, PH value is about 8.
 · Conductive agent: non-polar material, grape chain, water content 3-6%, oil absorption value ~300, particle size is generally 2-5 μm; mainly common carbon black, superconducting carbon black, graphite milk, etc. Superconducting carbon black and graphite emulsion are generally selected for high-volume applications; usually medium.
 · PVDF binder: non-polar material, chain, molecular weight ranging from 300,000 to 3,000,000; molecular weight decreases after water absorption, poor viscosity.
 · NMP: A weakly polar liquid used to dissolve/swell PVDF and to dilute the slurry.
3.2 Pretreatment of raw materials
 · Lithium cobaltate: dehydrated. Generally, it is baked at a pressure of 120 oC for about 2 hours.
 · Conductive agent: dehydrated. Generally, it is baked at 200 °C for 2 hours or so.
 · Adhesive: Dehydrated. Generally, it is baked at 120-140 oC for 2 hours at normal pressure, and the baking temperature is determined by the molecular weight.
 · NMP: Dehydration. Use dry molecular sieve dehydration or use special reclaiming facilities for direct use.
3.3 Mixing of raw materials:
 · Dissolution of the binder (according to standard concentration) and heat treatment.
 · Lithium cobaltate and conductive ball milling: The powder is initially mixed, and the lithium cobalt oxide and the conductive agent are bonded together to improve the agglomeration and conduction. After being formulated into a slurry, it is not separately distributed in the binder, and the ball milling time is generally about 2 hours; in order to avoid mixing impurities, an agate ball is usually used as a ball mill meson.
3.4 Dispersion and wetting of dry powder:
 · Principle: The solid powder is placed in the air. As time passes, part of the air will be adsorbed on the surface of the solid. After the liquid binder is added, the liquid and the gas will start to compete for the solid surface; if the solid and gas adsorption force ratio The liquid has strong adsorption force, and the liquid cannot wet the solid; if the solid-liquid adsorption force is stronger than the gas adsorption force, the liquid can wet the solid and extrude the gas.
When the wetting angle is ≤ 90 degrees, the solid is wetted.
When the wetting angle is >90 degrees, the solids are not wetted.
All members of the positive electrode material can be wetted by the binder solution, so the positive powder dispersion is relatively easy.
 · The impact of decentralized methods on dispersion:
A, standing method (long time, poor effect, but does not damage the original structure of the material);
B. Stirring method; rotation or rotation plus revolution (short time, good effect, but it may damage the structure of individual materials).
 · The effect of the paddle on the dispersion speed. The agitating paddles generally include a serpentine shape, a butterfly shape, a spherical shape, a paddle shape, a gear shape, and the like. Generally, the serpentine, butterfly, and paddle type agitating paddles are used to deal with the initial stage of materials or ingredients that are difficult to disperse; the spherical and gear shapes are used to disperse the less difficult state, and the effect is good.
 · The effect of stirring speed on the dispersion speed. Generally speaking, the higher the stirring speed, the faster the dispersion speed, but the greater the damage to the material itself and the equipment.
 · The effect of concentration on dispersion speed. Generally, the smaller the slurry concentration, the faster the dispersion speed, but too thin will result in waste of material and aggravation of slurry precipitation.
 · The effect of concentration on bond strength. The higher the concentration, the greater the softening strength, the bonding strength
The larger the concentration, the lower the bonding strength.
 · The effect of vacuum on the dispersion speed. The high vacuum is beneficial to the gas discharge of the material gap and the surface, and the difficulty of liquid adsorption is reduced; the difficulty of uniformly dispersing the material under the condition of complete weight loss or reduced gravity will be greatly reduced.
 · The effect of temperature on dispersion speed. At a suitable temperature, the slurry flows well and is easily dispersed. Too hot slurry is easy to crust, and the flow of too cold slurry will be greatly reduced.
 · Dilution. The slurry is adjusted to a suitable concentration to facilitate coating.

4. Principle of negative electrode dosing (roughly the same principle as positive electrode dosing)
4.1 Physical and chemical properties of raw materials.
 · Graphite: Non-polar material, easily contaminated by non-polar substances, easily dispersed in non-polar substances; not easy to absorb water, and not easy to disperse in water. Contaminated graphite, after being dispersed in water, is easy to re-agglomerate. The general particle diameter D50 is about 20 μm. The particles are various in shape and irregular, and are mainly spherical, flaky, fibrous, and the like.
 · Water binder (SBR): a small molecular chain emulsion that is highly soluble in water and polar solvents.
 · Anti-precipitation agent (CMC): polymer compound, soluble in water and polar solvent.
 · Isopropanol: weakly polar substance, which can reduce the polarity of the binder solution after adding, improve the compatibility of graphite and binder solution; has strong defoaming effect; easily catalyzes the binder network cross-linking, improves Bond strength.
Ethanol: weakly polar substance, which can reduce the polarity of the binder solution after adding, improve the compatibility of graphite and binder solution; has strong defoaming effect; easily catalyzes the bonding of the adhesive line and improves the bonding strength ( The effect of isopropanol and ethanol is essentially the same, and cost factors can be considered in mass production and then which one to add.
 · Deionized water (or distilled water): Diluent, added as appropriate to change the flow of the slurry.
4.2 Pretreatment of raw materials:
 · Graphite: A, mixed to homogenize the raw materials and improve consistency. B, 300 ~ 400 ° C atmospheric pressure baking, remove surface oil substances, improve the compatibility with water binder, round the surface of the graphite edge (some materials to keep the surface special, not allowed to bake, otherwise the performance is reduced).
 · Water binder: Dilute properly to increase dispersibility.
4.3 Blending, wetting and dispersion:
 · Graphite is very different from the binder solution and is not easily dispersed.
 • The graphite may be initially wetted with an aqueous alcohol solution and then mixed with the binder solution.
 · Stirring concentration should be appropriately reduced to improve dispersion.
 · The dispersion process is to reduce the distance between the polar and non-polar objects and increase the potential energy or surface energy. Therefore, for the endothermic reaction, the overall temperature decreases when stirring. If the conditions permit, the stirring temperature should be raised appropriately to make the heat absorption easier, while increasing the flow and reducing the difficulty of dispersion.
 · The stirring process, such as adding vacuum degassing process, removes gas and promotes solid-liquid adsorption, and the effect is better.
 · The principle of dispersion and dispersion are discussed in detail in the relevant content of the positive electrode batching and will not be explained in detail here.
4.4 Dilution. The slurry is adjusted to a suitable concentration to facilitate coating.

5. Ingredients Note:
 · Prevent mixing of other impurities;
 · Prevent slurry splashing;
 · The concentration of the slurry (solid content) should be gradually adjusted from high to low to avoid adding trouble;
 · Pay attention to scraping and scraping the bottom during the mixing process to ensure uniform dispersion;
 · The slurry should not be left for a long time to avoid precipitation or even reduction;
 · The materials to be baked must be sealed and cooled before they can be added to avoid the change of the material quality of the components;
 · The length of the mixing time is mainly based on equipment energy and material loading; the use of the stirring paddle is replaced by the difficulty of slurry dispersion. If the replacement cannot be replaced, the rotation speed can be adjusted from slow to fast to avoid damage to the equipment;
 · Screen the slurry before discharge to remove large particles to prevent breakage during coating;
 · Strengthen the training of the ingredients to ensure that they have the expertise to avoid a major disaster;
 · The key to the ingredients is to spread evenly, master the center, and other methods can be adjusted.

6. General:
With the increasingly transparent battery process, lithium-ion battery manufacturers are increasingly classifying ingredients as core secrets, because the selection, processing and rational matching of materials contain too many technicians' efforts, the same materials, and some manufacturers use It is particularly smooth, and some manufacturers are in trouble. Some manufacturers can make high-end batteries with medium-grade materials, while some manufacturers use the best materials to make batteries.