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LFP and NMC batteries are two common types of lithium-ion battery and some customers are often confused when faced with the choice of battery cells. Let’s take a look at the differences between them.
1.Materials
LFP and NMC are both lithium-ion batteries, but they are made up of different materials. The positive materials for lithium-ion batteries are lithium cobaltate, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate, etc.
LFP batteries are also known as LiFePo4 batteries, which use lithium iron phosphate as the positive material. NMC battery is a lithium-ion battery with nickel salt, cobalt salt and manganese salt as raw materials for the positive material, and the ratio of nickel, cobalt and manganese inside can be adjusted according to the actual.
Because of the different materials used also lead to the voltage of these two types of battery cells are different. LFP batteries usually have a nominal voltage of 3.2v and a standard charge/discharge voltage range of 2.5v to 3.65v. NMC batteries usually have a nominal voltage of 3.7v and a standard charge/discharge voltage range of 2.75v to 4.35v.
2.Energy Density
According to the public information of Chinese companies, the energy density of high-end NMC battery cell is about 250Wh/kg, while the energy density of LFP battery cell is about 180Wh/kg. In this point of view, the energy density of NMC battery cell is greater than LFP battery cell.
Higher energy density means smaller size in the same power situation. That is, the same volume, NMC batteries can store more power than LFP batteries.
3.Cycle Life
In the same number of cycle life, the residual capacity of LFP battery is also more than NMC battery only. NMC battery cycle 3900 times, the remaining capacity of 66%, LFP battery cycle 5000 times, the remaining capacity of 84%.
If the remaining capacity of 80% of the initial capacity as the end point of the test, the current LFP battery by laboratory testing, most of the cycle life of more than 3500 times, part of the 6000 times. And NMC battery test cycle life in about 2500 times, in the cycle life of this point, LFP battery cycle life is much longer than the NMC battery.
4.Price
Because LFP batteries do not contain precious metal materials, so the cost of raw materials can be compressed relatively low. The NMC battery is lithium nickel cobalt manganate as the positive material, cobalt is a precious metal, so the cost will be much more expensive than LFP batteries.
5.Safety
NMC battery liquid electrolyte is flammable and explosive, easily triggering thermal runaway during long-term use, and the growth of lithium dendrites during charging and discharging can easily pierce the diaphragm, causing short circuit of the battery and causing safety hazards.
The thermal stability of LFP positive material is much better than NMC lithium. LFP battery has a very high stability up to 500℃, and the possibility of thermal runaway only occurs when it exceeds 800℃. In addition, even in the event of thermal runaway, LFP battery heat is very slow, and decomposition will not release oxygen, reducing the risk of fire.In contrast, NMC batteries begin to dissolve at about 300℃.
It can be seen that LFP batteries have an advantage over NMC batteries in terms of safety.
6.Low-temperature Performance
The low temperature performance is mainly reflected in the charging performance and battery capacity, which is determined by the intrinsic characteristics of the battery. In the same low-temperature environment, LFP battery charging speed is much slower than NMC batteries, capacity decay is also more than NMC battery. Therefore, the low-temperature performance of NMC batteries is better than LFP batteries.
But this deficiency can be compensated by some methods. Because we usually assemble the battery cells into battery modules or packs, this time there is a lot to manipulate and it becomes very interesting. For example, at low temperatures, the external BMS heating system can be controlled to keep the internal battery environment at a very good temperature by means of BMS thermal management + materials. The heat pump used by Tesla is based on a similar principle, with thermal management of the BMS to achieve optimal performance of the internal temperature of the battery at low temperatures.
From the above analysis, we can see that LFP battery in safety, cycle life and price superior possession; NMC battery in energy density, low temperature performance is superior. Therefore, objectively speaking, there is no difference between good and bad, and there is no difference between superior and inferior, different batteries it applies to different products or environments.
Luoyang Tianhuan energy technology Co., LTD
website:www.lythbattery.com
E-mail:info@lythbattery.com