What Are The Categories Of Cathode Materials For Lithium-ion Batteries?

Power batteries (lithium-ion batteries) are the heart of new energy vehicles. Generally speaking, the cost of power batteries accounts for about 40% of that of new energy vehicles. The cathode material is the core of the power battery, and its cost in the power battery is as high as about 40%.

The choice of cathode material directly determines the performance of the battery. Because the positive electrode material has a greater impact on the battery performance, many researchers have devoted themselves to the development of higher performance positive electrode materials, such as lithium nickelate, lithium cobaltate, lithium titanate, and so on.

1. Lithium nickel oxide. Lithium nickel oxide is mainly represented by lithium nickel oxide. The product characteristics are similar to nickel cobalt oxide, but the price is lower than that of nickel cobalt oxide. Because of its high energy density, it can reach 274mAh/g, which is an ideal high energy density. Lithium-ion battery cathode material, but its safety performance is too poor, and the number of cycles is relatively low, so there are not many manufacturers using lithium nickelate as lithium-ion battery cathode material.

2. Lithium cobalt oxide. Lithium cobalt oxide is mainly represented by lithium cobalt oxide, which has five high characteristics, namely high energy density, high price, high power, high degree of commercialization, and high cycle life. The shortcomings are also obvious. There is a serious shortage of cobalt salts in my country. Need to be imported.

3. Lithium titanium oxide. The typical representative of lithium titanium oxide is lithium titanate. Zhuhai Yinlong occupies a dominant position in this field. The advantage of lithium titanate is fast charging, but the disadvantage is that it has low energy density and requires charging for a period of time. Another advantage is safety, and the third advantage is that the number of cycles can reach 20,000.

4. Nickel and cobalt multi-element oxides. This is the multi-element oxide we often say. The most common ones are lithium nickel cobalt manganese oxide and lithium nickel cobalt aluminate. Among them, lithium nickel cobalt manganate is divided into lithium nickel cobalt manganate 111 and lithium nickel cobalt manganese oxide 523. Nickel cobalt manganese lithium 622, nickel cobalt manganese lithium 811, but nickel cobalt lithium aluminate is not so popular, this technical route is mostly provided by Panasonic to Tesla for use, in which the ratio of nickel cobalt lithium aluminate is 0.8 to 0.15 Than 0.05.

5. Lithium manganese oxide. Lithium manganese oxides are mainly represented by lithium manganese oxide and lithium permanganate. The resources are relatively abundant in my country, and the products are currently a research hotspot. Among them, LiMn2O4 has a higher energy density, but its stability is greatly reduced, especially Under high temperature conditions, LiMn2O4 is unstable, but its main advantages are obvious. The product is pollution-free and has good safety performance.

6. Lithium iron phosphorus oxide. The main representative of lithium iron phosphorous oxide is lithium iron phosphate. Its product performance is balanced, non-toxic and non-polluting, and the number of cycles is not less than 2000. When used as the power source of passenger cars, the safety performance belongs to the high level.

In addition, the candidate cathode materials for lithium-ion batteries can be divided into three main categories according to the structure: (1) LiMO2 (M=Co, Ni, Mn) cathode materials with layered structure; (2) LiMn2O4 cathode materials with spinel structure; ( 3) LiFePO4 cathode material with olivine structure.