“Do you know about the research on ternary materials for lithium ion batteries? With the rapid development of society, our ternary materials for lithium ion batteries are also developing rapidly, so do you know the detailed analysis of ternary materials for lithium ion batteries? Let the editor lead you to understand the relevant knowledge in detail.
Do you know about the research on ternary materials for lithium ion batteries? With the rapid development of society, our ternary materials for lithium ion batteries are also developing rapidly, so do you know the detailed analysis of ternary materials for lithium ion batteries? Let the editor lead you to understand the relevant knowledge in detail.
As the energy density of lithium iron phosphate basically lacks room for significant improvement, in the context of the country’s increasing requirements for the cruising range of new energy passenger vehicles, BYD, which has always been regarded as the adherent of the lithium iron phosphate route, began to develop in new energy vehicles. The energy model Tangshang uses ternary lithium-ion batteries, and more domestic new energy production companies, including BAIC, JAC, Chery, SAIC, etc., have also begun to abandon the lithium iron phosphate route and switch to the field of ternary lithium-ion batteries.
Generally speaking, the cathode material of lithium-ion battery should meet the following requirements: allow a large amount of Li+ intercalation and deintercalation (large specific capacity); have a high redox potential (high voltage); good intercalation and deintercalation reversibility, small structural change (long cycle life) ;High lithium ion diffusion coefficient and Electronic conductivity (low temperature, good rate characteristics); high chemical/thermal stability, good compatibility with electrolyte (good safety); rich in resources, environmentally friendly, and cheap (low cost, environmental Protection). Lithium intercalation compounds, such as LiMn2O4, LiFePO4, LiCoO2, and ternary materials Li(NixCoyMnz)O2, are commonly used as positive electrodes in commercial lithium-ion batteries.
According to reports, in 2017, the output value of cathode materials for lithium-ion batteries in my country reached 9.575 billion yuan, of which ternary materials were 2.74 billion yuan, accounting for 28.6%; in the field of power lithium batteries, with the launch of BAIC EV200, the number of ternary materials soared . Chery EQ, JAC IV4, Zhongtaiyun 100, etc. all use ternary power lithium batteries.
The preparation of ternary materials for lithium-ion batteries is divided into two stages. The first step is the preparation of ternary material precursors, including the synthesis of mixed solutions of nickel, cobalt and manganese ions, the precipitation reaction of mixed solutions and precipitants, and aging, washing and filtration. drying; the second stage is to prepare ternary materials for lithium-ion batteries, including mixing, ball milling and sintering of lithium salts and precursors.
Generally, the comparative advantages of ternary materials for Li-ion batteries are obvious: high specific capacity, long cycle life, good safety performance and low price. This comes from the synergy of three elements: cobalt reduces the mixed cation space and stabilizes the layer. Nickel can increase the capacity of the material; manganese can reduce costs and improve safety.
Under high pressure, various side reactions between the cathode material and the electrolyte are more serious, and the safety becomes worse. Therefore, high-voltage-resistant electrolytes greatly limit the market application of high-nickel ternary materials. In contrast, the development of high-nickel ternary materials is faster. Li(NixCoyMnz)O2 (x = 1/3, 0.5, 0.6, 0.7, 0.8) series materials were synthesized by co-precipitation method, and the effect of Ni content on electrochemical performance, structure and thermal stability was investigated, and it was found that the electrochemical performance The properties and thermal properties are closely related to the Ni content. As the Ni content increases, the specific capacity of the material and the amount of residual alkali increase, and the capacity retention and safety will decrease.
With the continuous development of technology, the current ternary materials for lithium-ion batteries still have two shortcomings: one is a relatively low platform, and the other is a low first-time charge-discharge efficiency. However, under the strong attraction of comparative advantages, more and more battery manufacturers have begun to be interested in ternary materials for lithium-ion batteries, and are preparing or have begun to produce ternary materials for lithium-ion batteries.
Ternary materials have gradually become the mainstream trend in the power lithium battery market, and high-nickel ternary materials have become a hot spot in research and development and industrialization. Nissan, Tesla, GM, Mitsubishi Outlander and other important domestic and foreign car companies, as well as domestic passenger cars produced by BAIC New Energy, BYD, Geely Automobile, etc., have used ternary or binary high specific energy batteries. BYD, which has always insisted on using lithium iron phosphate, has also begun to use ternary batteries. The world’s large ternary material companies are mainly concentrated in China, Japan and South Korea, which together account for about 50% of the market share. The deployment of Japanese companies is relatively early, and the technology accumulation is relatively strong. Korean companies have risen rapidly and have now reached a high level in terms of technology and quality control. At present, major domestic battery companies have also turned to the development of ternary materials, and the industrial concentration and technical level have been continuously improved.