High-nickel ternary battery materials have become the trend of "燎原"

Lithium cobalt cobalt manganate (LiNixCoyMn1-x-yO2) is currently the most mainstream ternary battery material and is considered to be the future development trend. It uses cobalt, manganese and nickel salts as raw materials to obtain different electrode characteristics by blending the ratios of cobalt, manganese and nickel.

If you say that the battery material is the hottest now, I am afraid it is a high-nickel ternary material. Compared with lithium iron phosphate and low-nickel ternary materials, high-nickel ternary materials have a greater specific energy advantage due to the higher proportion of nickel. From 333, 532, to 622, 711 to 811 (the ratio of nickel, cobalt and manganese), in recent years, with the input of research and development, the high-nickel process of ternary materials “cannot stop”.

The ternary material "high nickel" process accelerates safety and is still being solved

High-nickel ternary battery materials have become the trend of "燎原"

If the high-nickel ternary material battery is still in the research and development stage of individual manufacturers and academic circles in the first two years, from 2016 onwards, the research and development and production of high-nickel ternary batteries have shown the trend of “燎原”.

Recently, Huang Shilin, president of Ningde Times (CATL), a leading domestic power battery company, said on the relevant occasions that the Ningde era will gradually be based on lithium iron phosphate/graphite, ternary, high-nickel ternary/silicon carbon and solid lithium and air metal. Battery evolution. During the “Thirteenth Five-Year Plan” period, the Ningde era will focus on the development of high-nickel ternary/silicon carbon batteries and strive to achieve the goal of 350Wh/kg. A dedicated team has been organized to ensure that mass production targets are met.

Yiwei Lithium Energy also stated on its investor interaction platform that high-nickel NCA (nickel-cobalt-aluminum), NCM622 and NCM811 are the most important development directions of ternary power batteries. The company has completed the planning of NCM622 ternary power battery.

Dangsheng Technology said that with years of experience in research and development and production of high-nickel multi-component positive electrode materials, the company's NCM622 ternary cathode material has been mass-produced and approved by domestic and international customers, and is applied to the field of new energy vehicle power batteries. The demand for products is in short supply.

According to relevant media surveys, although the current application of ternary battery companies is still NCM333 and NCM523 batteries, NCM622 has entered the material supply chain of some enterprises. With the high nickelization process of the material system, it is expected that the domestic ternary battery companies will start to apply NCM811 and NCA materials next year, and the energy density of the battery cells will move from 200 wh/kg to 250-300 wh/kg.

Security issues are under continuous resolution

It is well known that the higher the nickel content in the ternary material, the worse the stability of the material and the worse the safety.

At present, although the industry has developed a high-nickel ternary battery material "tune" has been set, in order to maintain its high specific energy while taking into account cycle life and safety, domestic materials and battery companies can be described as painstaking, its safety is still Continue to solve.

According to industry experts, the safety of ternary high-nickel materials can be solved step by step through material modification optimization, surface coating, and adjustment of electrolyte and anode materials.

In terms of material modification, doping some metal ions and non-metal ions in the ternary material lattice can improve the electronic conductivity and ionic conductivity, improve the output power density of the battery, and improve the stability of the ternary material structure; Secondly, coating the surface of the material with some suitable metal compounds, lithium salts or some simple substances can also physically separate the active material from the electrolyte, reduce the occurrence of side reactions, and inhibit the dissolution of transition metal ions in the electrolyte. The inactive coating layer with a certain mechanical strength can also slow down the collapse of the electrode material structure during long-term circulation; further, the use of an additive to optimize the electrolyte can effectively promote the formation of a high-quality surface film on the surface of the electrode material while suppressing Oxidative decomposition of the electrolyte.

In addition, industry insiders pointed out that high-nickel ternary material batteries also put forward higher requirements for manufacturing environment, production equipment, and battery manufacturing processes.

At present, in the safety of high-nickel ternary materials, industry-leading companies such as BYD and Tianjin Lishen are working hard to solve and improve.

Tianjin Lishen said that for the characteristics of high-nickel ternary battery materials, the company has developed a multi-element coating technology to maintain its capacity ratio while improving material properties. In the electrolyte, through the use of new antioxidant additives, To improve the cycle performance of the battery, reduce the expansion of high-nickel materials during use; in the battery process, use a new type of adhesive and gradient pure process to improve the cycle life of the battery, reduce the expansion of the silicon material during use, to ensure Battery safety.

BYD staff said on the relevant occasions that in order to completely solve the safety problem of the high-nickel ternary material system, BYD tried to use the silicon material as the battery negative electrode, and made great adjustments to the conductive agent, the connecting agent and the preparation process. On the electrolyte, BYD has increased the testing and development of high temperature resistant high pressure electrolytes and even solid electrolytes.