Wei to push 75 degrees ternary iron lithium battery pack ternary "mash-up" lithium iron phosphate will become the mainstream in the future?

Half a month after Ouyang Minggao, academician of the Chinese Academy of Sciences, made the judgment of "ternary and lithium iron phosphate battery hybrid PACK" to become a power battery system innovation, Lailai Automobile took the lead in commercializing this system.

On September 23rd, Xilai announced the official launch of the ternary lithium iron standard battery pack, which uses a mixture of ternary lithium formula and lithium iron phosphate formula, which not only increases the capacity of the old 70kWh battery pack by 5kWhh, but also improves its cycle life.

"there have been 'mash-up' technical solutions for ternary (lithium) batteries with other batteries, such as lithium manganate batteries, but they have not been widely used due to cost problems." Wang Rongjin, a partner of Shanghai Jinbang Equity Investment Management Company, told reporters that the main idea of the battery "mash-up" plan is to eliminate the disadvantages of its physical and chemical characteristics as far as possible while maintaining the respective advantages of the cells involved in the group. to achieve the best solution.

In the current power battery applications, lithium iron phosphate (LFP) and ternary lithium (NCM) batteries occupy the absolute advantage. According to the China Automotive Power Battery Industry Innovation Alliance, in August, the number of vehicles equipped with ternary batteries was 5338.1MWH, while that of lithium iron phosphate batteries was 7214.5MWH, accounting for 99.94% of the total power battery installed vehicles that month. However, because of their inherent physical and chemical properties, there are obvious long and short plates in both LFP, and NCM. Among them, the advantage of LFP lies in its relatively high safety and low cost, but its performance is poor in winter. On the contrary, although NCM has the advantages of high energy density and better low temperature in winter than LFP, its higher activity also brings higher safety risks.

"not only that, in the charge and discharge, due to the LFP Discharge curve is straight, resulting in the vehicle SOC (State of Charge, vehicle remaining power) is not easy to calibrate, bringing a poor user experience to the car owner." Some industry analysts believe that this is also one of the reasons for car companies such as Weilai to give up LFP. "this time Weilai adopts the mixed-up scheme of LFP and NCM, which is an attempt on the basis of solving the different SOC estimation methods of the two battery systems."

This is demonstrated by an invention patent applied for by Xilai in January this year. In the patent application, entitled "A battery system, its SOC estimation method, and computer devices and media," Weilai mentioned two battery systems, LFP and NCM. Thus it can be seen that there are early preparations for the "mash-up" scheme of LFP and NCM.

According to the official statement of Xilai Automobile, the battery pack, which uses the LFP and NCM "mash-up" scheme, can reduce the low temperature life loss by 25%, the power estimation accuracy is the same as that of the ternary lithium battery, and the application of the new generation CTP technology simplifies manufacturing and assembly by 10%, increases volume utilization by 5%, and energy density increases by 14% to 142Wh/kg.

"Weilai has only done part of the optimization of BMS (battery management system), and the battery group solution is still put forward in the era of Ningde, a battery supplier." The above industry analysis said.

Just half a month before the launch of the ternary lithium iron standard battery pack, Ouyang Minggao, academician of the Chinese Academy of Sciences and vice president of the China Electric vehicle Association, said at the "Seminar on Automotive Technology Innovation and Policy suggestions in the era of Power diversification" that the return of lithium iron phosphate batteries is a major trend, now is a "blade battery", and the future is the CTV, that is, the battery is directly combined with the car body. However, due to the attenuation of the range in winter, ternary lithium electricity also has a market; as a system innovation, it may be the combination of ternary and lithium iron phosphate to achieve the complementarity of safety and environmental adaptability.

"even after the commercialization of solid-state batteries, the 'mash-up' of batteries with a variety of cathode materials is indeed likely to become a trend." Wang Rongjin believes that the proposal of a variety of technical solutions not only gives car companies more choices, but also enriches the application of different scenarios for car owners.