Application of artificial graphite

The most widely used anode materials are still artificial graphite and natural graphite. Artificial graphite needs to convert the preparation raw materials to graphite. The raw materials of artificial graphite mainly include petroleum coke and needle coke, domestic coke, and imported coke. Different raw materials lead to great differences in cost, product price, and performance.

1. Classification of negative electrode materials

Artificial graphite is main raw material of negative electrode material.

It mainly needs four processes: crushing, granulation, graphitization, and screening. Crushing and screening are relatively simple, mainly including granulation and graphitization, reflecting the industry threshold of negative electrode technology and enterprise production level. Among them, the graphitization processing fee is generally 20000-25000 yuan/ton, which accounts for the highest proportion of the production cost of artificial negative electrodes except for raw materials.

Performance: the capacity of high-end artificial graphite is more than 355mah / g, and the compaction density is more than 1.7g/cm3; The capacity of artificial graphite at the middle end is more than 345mah / g, and the compaction density is about 1.55-1.65g/cm3; The capacity of low-end artificial graphite is more than 340mah / g, and the compaction density is about 1.5g/cm3. The first efficiency of negative electrode materials on ternary batteries and lithium iron phosphate batteries is also different. The first efficiency of lithium iron phosphate negative electrode is more than 94%, and the first efficiency of ternary negative electrode needs to be matched with that of positive electrode (about 88%), so it is slightly lower, about 93%.

2. Negative electrode Market Pattern

From the perspective of industry pattern, the negative electrode industry has stepped out of a mature leading company after years of development. In terms of natural graphite, better is the only company with a market share of more than 70%, while the competition for artificial graphite is fierce. The market shares of the top three enterprises, Jiangxi Zichen (a wholly-owned subsidiary of putilai), Ningbo Shanshan, and Dongguan Kaijin, account for about 20%, and CR3 reaches more than 60%. It is a link to the high concentration of the four main materials of power lithium battery.

3. Negative electrode Market Characteristics

Artificial graphite occupies a high share in the domestic high-end consumption and power market:

1) although the capacity, heat transfer, and conductivity of natural graphite are better than artificial graphite, it is inferior to artificial graphite in the two performance indexes most concerned by downstream applications (magnification performance and cycle life); 2) Because the electrolyte technology of domestic power battery plants is not mature if natural graphite with different particle sizes and more surface defects is selected, it will have poor compatibility with the electrolyte and easily lead to more side reactions, to accelerate and shorten the cycle life. However, artificial graphite has low requirements for the battery system and has relatively good compatibility with the electrolyte.

(2) Under the pressure of cost reduction and the gradual promotion of technology, the domestic medium, and low-end power battery cathode market will gradually switch to natural graphite cathode material or composite graphite with lower cost. 1) The average market price of natural graphite is 31000 yuan/ton, which is 72% on the average market price of artificial graphite. The conversion from artificial graphite to natural graphite will give the negative electrode more than 20% cost reduction space; 2) The trend of ternary to lithium iron phosphate conversion of power batteries of medium and low-end models is clear. Natural graphite and lithium iron phosphate can complement each other in the material system (specific energy density, high-temperature performance, and low-temperature performance), and their costs are low in their respective systems, which will be well adapted to the cost reduction of new energy vehicles.