According to official data, M3P battery is a battery developed by CATL based on a new material system. Its energy density is 210Wh/kg, which is about 15% higher than Lithium iron phosphate battery. Its cost is equivalent to Lithium iron phosphate battery, which is lower than ternary lithium battery. The cathode material of the CATL M3P battery is doped with ternary lithium material and lithium manganese iron phosphate material, which can solve the problems of short cycle life and large internal resistance of lithium manganese iron phosphate battery.

At the 2022 World Power Battery Conference held in July, Wu Kai, chief scientist of CATL, said that the company's M3P battery has been mass produced and will be put into market next year. In the future, CATL will divide new energy vehicles into three segments: 1000km, 700km and 300-500km. In the 700km mainstream new energy vehicle market, the solution of CATL is M3P battery cell+Kirin battery structure.

In March this year, Robin Zeng, chairman of CATL, said at the company's annual performance presentation that the new generation of M3P battery of CATL is expected to be mass produced and delivered this year. "In the case of large-scale application, M3P battery can reduce costs and improve efficiency, and its low-temperature performance, energy density and cost are better than Lithium iron phosphate battery and ternary lithium battery," Robin Zeng said.

The CATL M3P battery may be the first modified model 3 produced in Tesla Shanghai factory in the third quarter of this year, and the battery pack equipped with it will be upgraded from the previous 60kWh of Lithium iron phosphate battery pack to 66kWh. In addition, the battery pack using the CATL M3P battery is not only used for the modified Model 3, but also a platform solution, so the modified Model Y will be used for this purpose.

What is the significance of M3P battery to the CATL?

In the opinion of industry insiders, if the highlight of the Kirin battery that was mass produced by CATL in March this year is the innovative breakthrough in the battery pack structure (Kirin battery is the third generation CTP technology of CATL, which can improve the volume utilization rate and energy density of the battery pack through structural optimization), then M3P battery has achieved a leap in the performance of existing liquid lithium ion batteries mainly through the optimization of battery cathode materials.

According to the different cathode materials of batteries, the current mainstream power lithium batteries in the world are divided into nickel cobalt manganese ternary lithium batteries (NCM battery) and Lithium iron phosphate batteries (LFP battery). The latter has exceeded the ternary batteries in terms of output and loading capacity due to its low cost, strong safety and other advantages, but the energy density of Lithium iron phosphate battery has approached the "ceiling".

In this case, lithium manganese iron phosphate materials began to sprout in the industry.

It is understood that the lithium manganese iron phosphate material is to add manganese element on the basis of Lithium iron phosphate to improve the voltage platform.

The theoretical capacity of lithium manganese iron phosphate material is the same as that of Lithium iron phosphate, which is 170mAh/g; However, the electrode potential of lithium manganese iron phosphate relative to Li+/Li is 4.1V, much higher than 3.4V of Lithium iron phosphate, and it is located in the stable electrochemical window of organic electrolyte system. The high potential of 4.1V makes lithium manganese iron phosphate have the advantage of potential high energy density, which is its biggest advantage over Lithium iron phosphate. The crystal of lithium manganese iron phosphate is similar to that of Lithium iron phosphate, with olivine structure. The biggest advantage of this structure is its high stability. Even if all lithium ions are removed during charging, the structure will not collapse, so the safety performance is good.

In theory, the actual capacity of lithium manganese iron phosphate will play to the same extent as that of Lithium iron phosphate, and its energy density will be 15% -20% higher than that of Lithium iron phosphate. If combined with ternary materials, it can effectively integrate the characteristics of high safety, high energy density, and low-temperature performance. In addition, the raw material cost of lithium manganese iron phosphate is low and the environment is friendly. In terms of production process, it is similar to the production process of Lithium iron phosphate. It is synthesized by high-temperature Dry media reaction method and Hydrothermal synthesis method. The process is mature and suitable for batch production.

As early as 2015, CATL disclosed the patent of "a preparation method of lithium manganese iron phosphate as cathode material of lithium ion battery". In 2017, he also disclosed the related patent of "composite cathode material for lithium ion battery and its preparation method - a lithium manganese iron phosphate and Graphene composite cathode material and its preparation method".

From the name (M is the code of manganese element, P stands for the chemical formula PO ₄ phosphate), it is speculated that M3P battery is a lithium manganese iron phosphate battery, but CATL said that M3P battery is not exactly a lithium manganese iron phosphate battery, and the battery cathode material also contains other metal elements, which the company calls a ternary lithium battery of phosphate system. A professional said that the M3P battery of the CATL may be doped with two of the metal elements such as magnesium, zinc and aluminum, forming a substitution at some iron points, thus forming a ternary material of phosphate system to improve the charge discharge capacity and cycle stability.

However, Wu Kai, the chief scientist of CATL, previously admitted that "although the industry has studied M3P materials for many years, there are still some inherent problems that cannot be solved. The most typical is that the conductivity is not enough, which makes it difficult to apply them in the field of electric vehicles."

It is reported that the commonly used methods to enhance the conductivity of lithium manganese iron phosphate materials include the optimization of manganese iron ratio, coating of conductive materials, bulk ion doping, material nanocrystallization and other modification technologies. According to Wu Kai, "the research and development team of CATL solved the problem of insufficient conductivity by adding different elements to modify materials through long-term research and massive calculations."

Model 3+M3P=A perfect match?

It can be seen that according to the market positioning of the CATL for M3P batteries, it is also appropriate for them to choose Tesla Model 3 for the first launch.

At the World Power Battery Conference held in July last year, Wu Kai, the chief scientist of CATL, said, "M3P batteries can be used for mid-range models with a range of about 700km. For models with a range of about 700km, CATL used a medium nickel and low nickel ternary positive material scheme, which is relatively costly. Combined with the battery pack structure of 'Kirin Battery', M3P new materials can also meet the needs of such models."

Then in August, the market heard for the first time that CATL would supply M3P batteries to Tesla. It was said that the batteries were installed in the new version of Tesla Model 3 and Model Y models made in China, and the related models would be launched in 2023.

The energy density of the M3P battery will be about 15% higher than the existing Lithium iron phosphate battery, which is about 210 kWh/kg, which will increase the endurance mileage of the Model 3 produced by the Shanghai factory by 10%.

At present, the domestic model 3 is equipped with lithium iron phosphate battery supplied by CATL. The two versions of CLTC on sale have a combined driving range of 556km and 675km respectively. After upgrading the battery pack, it is expected to exceed 600km and 700km.