As for the new type of high temperature lithium battery cathode material, the reason why tungsten oxide ultrafine powder is selected as the key modifier is that the powder can greatly improve the heat resistance and chemical stability of electrode products.
Cathode material is one of the key materials that determine battery performance, and it is also the main source of lithium ions in current commercial lithium-ion batteries, and its performance and price have a greater impact on the product. Currently, the commonly used cathode materials are as follows:
(1) Lithium cobalt oxide: It has the advantages of high discharge platform, large specific capacity, good cycle performance, and simple synthesis process. However, the material contains more cobalt and has a higher cost. It is currently the best choice for small batteries.
(2) Lithium iron phosphate: its theoretical specific capacity is 170mAh/g, but the actual specific capacity can reach more than 150mAh/g. In addition, low cost, good safety and high cycle life are also its advantages.
(3) Ternary material: It can be balanced and regulated in terms of specific energy, cyclicality, safety and cost. Under normal circumstances, the increase of nickel content will increase the specific capacity of the material, but it will also make the cycle performance of the product worse; the presence of cobalt can make the material structure more stable, but too high content will reduce the product capacity; Existence can reduce costs and improve safety performance, but too high content will destroy the layered structure of the material. Therefore, finding the proportional relationship between these three materials to achieve the optimization of comprehensive performance is the focus of the research and development of ternary materials.
However, no matter what kind of cathode material, its performance will be affected by temperature. In a higher temperature environment, the surface of the positive electrode material is more likely to fall off, and the active material will more adversely react with the organic electrolyte.
In response to the above-mentioned problems, the researchers said that an appropriate amount of tungsten oxide powder can be added to the next generation of cathode materials because the powder has a higher melting temperature and chemical stability.
