Why should lithium iron phosphate batteries be charged above 0 degrees?

Celes · Sep 11, 2023

Lithium iron phosphate battery charging is the lithium ion from the positive electrode out of the electrolyte migration embedded in the negative electrode material process, lithium ion polymerization to the negative electrode, by six carbon atoms captured a lithium ion. At low temperatures, the chemical reaction activity is reduced, while the lithium ion migration slows down, the lithium ion on the surface of the negative electrode has not been embedded in the negative electrode has been reduced to lithium metal, and precipitation precipitation precipitation on the surface of the negative electrode to form lithium dendrites, which is easy to puncture the diaphragm resulting in a short-circuit within the battery, which can cause damage to the battery, resulting in a safety accident.

In addition, at low temperatures, the viscosity of the electrolyte will increase, and the lithium ion migration impedance will also increase; in addition, in the production process of lithium iron phosphate battery, the adhesive is also a very critical factor, and low temperatures will have a greater impact on the performance of the adhesive. In addition, lithium iron phosphate battery charging at low temperatures, lithium ions may not be embedded in the graphite anode in time, so that the precipitation of lithium metal dendrites formed on the surface of the anode, this reaction will consume lithium ions in the battery can be repeatedly charging and discharging, and significantly reduce the capacity of the battery, the precipitation of the lithium metal dendrites may also puncture the diaphragm, which affects the safety performance.

What do you think of it?

jennyzhang · Oct 17, 2023

The optimal level of operating temperature for #lithiumbatteries is 0 to 35℃. The low-temperature environment will reduce the activity of lithium ions, the lipo battery discharge capacity will be weak, and the use time will be shortened. If the lithium battery using in a low-temperature environment for a short period of time, the damage is only temporary and does not damage the battery capacity. The performance will recover when reinforcing the temperature.

However, if the battery is charged and discharged in a low-temperature environment for a long time, metal lithium will be separated out on the surface of the “battery anode”. This process is irreversible and permanently damage to the battery capacity. Like sometimes, at low temperatures, our smartphone will automatically shut down. It is for the purpose of protecting the battery, on the other side, it is also caused by the unqualified and aging of the self-battery.