First, the composition of the electrode:
1, the positive electrode composition:
a, lithium cobalt oxide: positive electrode active material, lithium ion source, for the battery to improve the lithium source.
b. Conductive agent: improve the conductivity of the positive electrode sheet, compensate the electronic conduction of the positive active material, increase the liquid absorption of the electrolyte of the positive electrode sheet, increase the reaction interface, and reduce the polarization.
c. PVDF adhesive: Lithium cobaltate, conductive agent and aluminum foil or aluminum mesh are bonded together.
d. Positive lead: Made of aluminum foil or aluminum strip.
2, the composition of the negative electrode:
a, graphite: negative electrode active material, which constitutes the main substance of the negative electrode reaction; mainly divided into natural graphite and artificial, graphite two major categories.
b. Conductive agent: improve the conductivity of the negative electrode sheet and compensate 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).
c. Additives: reduce irreversible reactions, improve adhesion, increase slurry viscosity, and prevent slurry precipitation.
d. Water binder: Bonding graphite, conductive agent, additive and copper foil or copper mesh together.
e, negative lead: made of copper foil or nickel strip.
Second, lithium battery ingredients Purpose: The batching process is actually mixing the various components in the slurry according to the standard ratio, and preparing into a slurry to facilitate uniform coating to ensure the consistency of the pole pieces. The ingredients generally comprise five processes, namely: pretreatment, blending, wetting, dispersion and flocculation of the raw materials.
Third, the principle of lithium battery ingredients:
(A), the principle of positive dosing
1. Physical and chemical properties of raw materials
(1) Lithium cobaltate: non-polar substance, irregular shape, particle diameter D50 is generally 6-8 μm, water content ≤ 0.2%, usually alkaline, PH value is about 10-11.
Lithium manganate: non-polar substance, irregular shape, particle size D50 is generally 5-7 μm, water content ≤ 0.2%, usually weakly alkaline, PH value is about 8.
(2) Conductive agent: non-polar substance, grape chain, water content 3-6%, oil absorption value ~300, particle size is generally 2-5μm; mainly common carbon black, superconducting.
Carbon black, graphite milk, etc., are generally selected for superconducting carbon black and graphite emulsion in large-volume applications; usually medium.
(3) PVDF binder: non-polar substances, chains, molecular weight ranging from 300,000 to 3,000,000; molecular weight decreases after water absorption, viscosity is deteriorated.
(4) NMP: a weakly polar liquid used to dissolve/swell PVDF and to dilute the slurry.
