Lithium ferromanganese phosphate advantage & disadvantage of adding manganese

In the initial stage of new energy vehicles, 80% of the power battery market share was occupied by lithium iron phosphate (LFP). However, the emergence of the later subsidy policy made the market share of terathree lithium battery advance rapidly. By 2020, the installed volume of terathree lithium battery accounted for 61%.

But things started to change in 2021.

According to the new energy promotion and application recommended models catalog information released on the official website of the Ministry of Industry and Information Technology, in 2022, the maximum energy density of lithium iron phosphate battery system is 161.27Wh/kg, which has hardly changed in the past two years. Although lithium iron phosphate battery with low cost, strong safety and other advantages, in terms of production and loading volume, the energy density of lithium iron phosphate battery has been close to the ceiling.

In this context, lithium ferromanganese phosphate (LMFP), as an upgraded replacement material for lithium iron phosphate, has attracted much attention in the market.

Advantages of adding "manganese" to lithium iron phosphate battery

Lithium ferromanganese phosphate is a new cathode material which is obtained by adding manganese element on the basis of lithium ferromanganese phosphate. Its advantages mainly include:

(1) Lithium ferromanganese phosphate has the advantage of energy density compared with lithium ferromanganese phosphate. The voltage plateau of lithium ferromangate-phosphate is as high as 4.1V, which is significantly higher than that of lithium ferromangate-phosphate (3.4V). The high voltage platform can improve the energy density of the corresponding battery. Under the corresponding conditions, the theoretical energy density is 15%-20% higher than that of lithium iron phosphate, which can basically reach the level of terpolymer battery NCM523, so as to provide the electric vehicle with a higher range than lithium iron phosphate battery.

(2) Lithium ferromanganese phosphate has advantages in low temperature performance compared with lithium ferromanganese phosphate. The capacity retention rate of lithium ferromangate-phosphate can reach about 75% at -20℃, while the capacity retention rate of lithium ferromangate-phosphate is 60%-70%.

(3) Lithium ferromanganese phosphate has safety advantages over ternary cathode. Compared with ternary, lithium ferromanganese phosphate has olivine structure, which is more stable when charging and discharging, and has better safety and cycle stability than ternary.

(4) Lithium ferromanganese phosphate has cost advantage. Due to the rich manganese ore resources in the world, the cost of lithium ferromangate-phosphate only increases by about 5%-10% compared with lithium ferromangate-phosphate. Considering the improvement of energy density of lithium ferromangate-phosphate, the cost of lithium ferromangate-phosphate per watt hour is slightly lower than that of lithium ferromangate-phosphate, and significantly lower than that of terpolymer batteries.

Adding "manganese" disadvantages to lithium iron phosphate battery

BYD, a staunch supporter of lithium iron phosphate batteries, started to explore and upgrade lithium iron manganese phosphate as early as 2013, but it stopped developing related technology in 2016.

The reason behind the termination, besides the fact that the power battery subsidy policy at the time was not friendly to lithium ferromangate-phosphate, must also have been the material itself.

"The addition of manganese increases the energy density of the original lithium iron phosphate battery, but at the same time, the addition of manganese decreases the diffusion rate of lithium ions and the electronic conductivity of the material. Therefore, in order to achieve a higher discharge specific capacity of lithium ferromangate-phosphate, it is necessary to reduce the primary particle size of the material, but small nanoparticles also bring a series of side effects, such as reduced compaction, high water absorption, leading to poor high-temperature cycling performance and gas problems." "Said Xia Yonggao, a researcher at the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences.

In 21 years, Jiangsu Litai had held an exclusive exchange conference on lithium ferromangate-phosphate, which clearly mentioned: lithium iron is a semiconductor, adding carbon can be done, and lithium ferromangate-is an insulator, particles are still small, leading to difficult processing technology route. At present, no industry has a unified technical route, with technical barriers.

Development status of lithium ferromanganese phosphate

(1) Single Use

When used alone, although the theoretical capacity of lithium manganese phosphate is the same as lithium iron phosphate, 170mAh/g, its electrode potential is much higher than lithium iron phosphate, so it has the potential advantage of high energy density. When the actual capacity of lithium ferromanganese phosphate is brought into play to the same extent as lithium iron phosphate, its energy density increases by 15%-20% compared with lithium iron phosphate.

(2) Mixed Use

In addition to its own use, lithium ferromangate-phosphate is mixed with other cathode materials to improve battery performance, which is also a major direction of lithium ferromangate-phosphate industrialization.

For example, Xingheng Power Supply has made a major breakthrough in the improvement of lithium ferromangate-phosphate composite technology. "The core of this technology improvement is the mixing of lithium manganate and lithium ferromanganoate phosphate to improve the low temperature, safety and cycling performance of the battery." Zhao Chenglong, president of the battery engineering Institute of Xingheng power, said that it is expected that in the next two to three years, lithium ferromanganoate is still used in mixed.

In addition, GAogong lithium electricity believes that in the next 2-3 years, lithium ferromangano phosphate will be more used in the way of compound triadic materials. At present, there are still some problems when lithium ferromanganese phosphate is used alone. It is more suitable to be used as auxiliary material for ternary lithium battery, which can not only take into account the energy density, but also improve the safety performance of ternary battery. In the long run, as the cost decreases and the cycle performance improves, the upgrade process from auxiliary material to main material will be accelerated.

Ferromanganese lithium phosphate as is one of the upgrading direction of lithium iron phosphate batteries, although the past is limited by its low conductive performance and ratio of performance, but with the carbon coating and nano, doping and modification technology such as lithium technology progress, ferromanganese lithium phosphate conductivity, cycles and other shortcomings are compensated by gradually, head of the battery and the positive domestic enterprises in the aspect of patent to speed up the reserves, And has started the mass production planning, lithium ferromanganese phosphate industrialization process began to accelerate.