At present, battery manufacturers have not launched lithium iron phosphate (lifepo4 battery) batteries, but according to the characteristics of iron lithium batteries, they can theoretically be used to replace lead-acid batteries. The characteristic of the car battery is that it can discharge a large current, and the current can reach hundreds of amps when starting. After starting, it can be charged with high current, without memory effect, and the charging requirements are not high, as long as the voltage is not higher than 14.5v. There is no need for constant current charging, the current size can be charged, the risk is low, and the performance is relatively stable. The disadvantage is that the energy density is low, the self-discharge rate is large, it is bulky and the life is short.
Lithium iron phosphate battery (lifepo4 battery) was once widely used in electric vehicles, but was gradually replaced by ternary lithium battery due to low energy density and other reasons. BYD's proud iron battery is lithium iron phosphate battery (lifepo4 battery). At present, it is gradually replaced by ternary lithium batteries. The lithium iron phosphate battery (lifepo4 battery) has a monomer voltage of 3.2V and a charge cut-off voltage of 3.6v. If it is used in a car, four strings of N parallels are required, and the voltage is between 12.8-14.4v. This voltage is no problem for car startup.
The iron-lithium battery supports high current discharge, the standard discharge current is 3-5C, the high current continuous discharge supports 10c, and the instantaneous discharge current can reach more than 20C. This is why a small charging treasure can start the car. For example, an iron-lithium battery with a capacity of 12V8ah can easily reach more than 160 amps when it is instantaneously discharged at a current of 20C! And an iron-lithium battery with a capacity of 20ah can instantly start up to a current of more than 400 amps, and there is no pressure to start the car.
Although brand battery manufacturers have not launched lithium iron batteries for vehicles, some people are already assembling iron lithium batteries for sale. It can directly replace the AMG battery, and the capacity density is higher than that of the lead-acid battery, so the weight is much lighter. The starting current is also much larger than that of lead-acid batteries of the same capacity, and the voltage is also higher than that of lead-acid batteries. So the vehicle will start more smoothly than lead-acid batteries. However, the 4-series iron-lithium battery needs to be equipped with a protective plate, so the battery stability is definitely not as good as that of lead-acid batteries. Moreover, there is a certain risk of spontaneous combustion, and the long-term effect has not been verified at present. This is also the reason why battery manufacturers have not launched iron-lithium batteries!
