The important materials of lithium-ion battery pack include cathode material, cathode material, electrolyte and diaphragm.

Positive material: positive material accounts for a large proportion (the mass ratio of positive and negative materials is 3:1~4:1), because the performance of positive material directly affects the performance of lithium ion battery, and its cost also directly determines the battery cost.

The mixed dispersion process is the most important link in the whole production process of lithium ion battery, which has more than 30% impact on the quality of products. For electrode manufacturing of lithium ion battery, the positive paste is composed of adhesive, conductive agent, positive material, etc.

At present, LiCoO2 is still the most widely used cathode material in commercially produced lithium-ion battery packs. At present, the actual discharge capacity of LiFePO4 with olivine structure has reached about 95% of the theoretical capacity, and it has the advantages of low price, high safety, stable structure, no environmental pollution, etc. It is considered to be an ideal cathode material in large lithium ion batteries.

Negative electrode material: The negative electrode material has an important impact on the efficiency and cycle performance of the lithium ion battery. The performance of the negative electrode material also directly affects the performance of the lithium ion battery. The negative electrode material accounts for about 10-20% of the total cost of the lithium ion battery.

At present, there are only two kinds of large-scale commercial anode materials, namely graphite carbon materials and LTO. Other anode materials include Si, Sn and other alloy anode materials.

Carbon anode materials are a general term, which can be generally divided into three categories: graphite, hard carbon and soft carbon anode.

Electrolyte: The electrolyte of lithium ion battery pack is the carrier of ion transport in the battery. It is generally composed of lithium salt and organic solvent. Electrolyte is used to conduct ions between positive and negative electrodes of lithium ion batteries, which is the guarantee for lithium ion batteries to obtain high voltage, high specific energy and other advantages. Electrolyte is generally prepared from high-purity organic solvent, electrolyte lithium salt, necessary additives and other raw materials under certain conditions and in a certain proportion.

Diaphragm: In the structure of the lithium-ion battery pack, the diaphragm is one of the key inner components. The performance of the separator determines the interface structure, internal resistance, etc. of the battery, which directly affects the capacity, circulation, safety and other characteristics of the battery. The separator with excellent performance has an important use to improve the overall performance of the battery. The important purpose of the diaphragm is to separate the positive and negative electrodes of the battery, so as to prevent the short circuit caused by the contact between the two electrodes. In addition, it also has the function of allowing electrolyte ions to pass through.