When the lithium iron phosphate battery is charged by the external power supply, the electron e on the positive pole runs from the external circuit to the negative pole, and the lithium ion Li+"jumps" into the electrolyte from the positive pole, "crawls" through the winding holes in the diaphragm, and "swims" to the negative pole, where it is combined with the electrons that have already run. When the battery is discharged, the mechanism is just opposite to charging. Taking LiFePO as an example, its chemical reaction equation is:

Working principle diagram of lithium iron phosphate battery

Charging: LiFePO4 - xLi+- xe - → xFePO4+(1-x) LiFePO4

Discharge: FePO4+xLi++xe - → xLiFePO4+(1-x) LiFePO4

LiFePO, the correct chemical formula is LiMPO4, (M can be any metal, such as Fe, Co, Mn, Ti, etc.).

Its physical structure is olivine structure. From the perspective of structure, the cathode materials that can be used in lithium ion batteries can also be AyMPO4, Li1-xMFePO4, LiFePOMO, etc.

It is characterized by no precious elements, low raw material price and abundant resources of phosphorus, iron and lithium on the earth, so there is no big problem in the supply of materials.

In addition to the common characteristics of lithium batteries, there are also some unique advantages, such as moderate operating voltage (3.2V), large capacity (170mAh/g), high discharge power, fast charging, long cycle life (up to 2000 times), and high stability in high temperature and high heat environments.