1. Advantages of lithium iron phosphate battery
1) Long battery life
Under standard test conditions, the cycle life of a single cell LFP can generally reach more than 2000 times, or even more than 3500 times. Some specific energy storage batteries can reach 4000-5000 times. Under certain conditions, the service life can be as long as 7-8 years, which is also one of the primary conditions for selecting LEP for electric vehicles. The lead-acid battery, when used under the best conditions, has a service life of about 300 times, which may not exceed 3 years. The life of the group LEP battery pack can also reach about 800-2000 times.
2) Relatively high security
Compared with ternary lithium cobalate battery, the safety is the highest. This is mainly determined by the crystal structure of the LFP battery itself. Its P-O bond is relatively stable. Even in the case of overcharge or high temperature, it will not collapse like lithium cobalate. It will not deform or oxidize materials due to high temperature or overcharge, as in ternary. It can withstand overcharge and overdischarge within a certain range, and can recover more than 80% if it is set to zero for a short time; If overcharged to 100%, there will be no fire or explosion.
3) Good high-temperature performance
The thermal runaway temperature of LFP battery materials can reach 350 ℃ - 500 ℃, while lithium manganate, lithium cobalate and ternary batteries usually react violently at about 200 ℃. The working temperature can reach about 75 °, while the other three types of batteries, which work at about 70 ° for a long time, will have a serious impact on the life of the battery, and may even cause heat accumulation and finally heat out of control.
4) Light weight
The volume of lithium iron phosphate battery with the same specification and capacity is 2/3 of that of lead-acid battery, and the weight is 1/3 of that of lead-acid battery.
5) Large capacity of single electric core
As for lithium iron phosphate battery as power battery, the capacity of single cell can reach 2AH-1000Ah, which is impossible for other batteries. The single battery cell with large capacity can easily integrate CTP technology and CTC technology in electric vehicles to improve the energy density of batteries.
6) No memory effect
LFP battery can be charged as you use it, which will not affect the life of the battery and will not cause irreversible capacity generation. NiMH battery and lead-acid battery have memory effect.
7) Relatively low cost
Compared with ternary battery, the production cost of LEP battery is lower, mainly because the price of raw materials is lower than that of ternary battery.
8) Energy conservation and environmental protection
Compared with other types of batteries, lithium iron phosphate batteries do not contain heavy metals, which are green, non-toxic and pollution-free.
2. Disadvantages of lithium iron phosphate battery
1) The low temperature performance of the battery is poor
The low temperature performance of LEP battery is worse than that of ternary battery. The electronic conductivity of lithium iron phosphate anode itself is poor, and the lithium ion diffusion speed is slow. In addition, it is easy to polarize, reducing the capacity.
2) LEP cathode material is easy to contain metallic iron
In the sintering process of lithium iron phosphate, it is possible for iron oxide to be reduced to simple iron under high temperature reducing atmosphere. Simple iron will cause micro short circuit of battery, which is the most taboo substance in battery.
3) Relatively low energy density
Compared with the ternary battery, the energy density of lithium iron phosphate battery is low, and the maximum single cell does not exceed 200WH/KG. After being grouped, it is generally 120-140 WH/KG. However, for the ternary battery, the single cell can currently reach 350WH/KG, and after being grouped, it is 160WH-200WH/KG.
4) Relatively low product consistency
From the perspective of material preparation, the synthesis reaction of lithium iron phosphate is a complex heterogeneous reaction, including solid phosphate, iron oxide and lithium salt, carbon added precursor and reducing gas phase. In this complex reaction process, it is difficult to ensure the consistency of the reaction. As a result, the service life of a single electric core is up to 5000 times, while it may only be 800-2000 times after being grouped. The ternary battery has good consistency due to the preparation of materials.
5) Battery BMS has a relatively high cost
Because the change between the open circuit voltage and the SOC of lithium iron phosphate battery is very small between 30% and 70%, the battery management system needs to use other methods to predict the health status of the battery, which increases the difficulty of battery prediction and increases the cost of the battery.
6) The battery has intellectual property defects
At present, the basic patent of lithium iron phosphate is owned by the University of Texas in the United States, while the carbon coated patent is applied for by Canadians. These two basic patents cannot be bypassed. If patent royalties are included in the cost, the product cost will be further increased