Due to the poor performance of 48 volt lifepo4 battery lithium iron phosphate at low temperature, it can not adapt to specific low temperature climate and harsh environment at low temperature. At low temperature, it can significantly reduce the charge discharge capacity and charge discharge capacity of lithium iron battery. What's going on here? Next, let the editors of Energy Storage Electric tell us something.
China 48v lithium battery iron phosphate is a kind of material with cathode material, cathode material, diaphragm and electrolyte as electrolyte. Under low voltage conditions, the discharge voltage platform of lithium battery drops, the discharge capacity is low, the capacity decays quickly, and the magnification performance is poor.
Lithium iron phosphate battery with low temperature characteristics
1. Production environment
As a high-tech product with numerous chemical raw materials and complex processes, it has high requirements for environmental temperature, humidity, dust, etc. If it is not properly regulated, the quality of batteries will change.
2. Poor conductivity, slow lithium ion diffusion
When charging and discharging at high amplification rate, the actual specific capacity is small, which has been a problem puzzling the development of china deep cycle lithium battery 48v industry. Lithium iron phosphate has not been used on a large scale, which is the biggest problem at present.
3. Material effect
The conductivity of lithium iron phosphate anode is very low, and it is very easy to polarize, resulting in a decrease in capacity; The charging mode of the negative electrode is mainly to reduce the safety of the battery; At low temperature, the viscosity of electrolyte will increase, and the migration resistance of lithium ion will also increase. The fourth is the adhesive, which has a great impact on the low-temperature performance of the battery.
4. Positive material
The three-dimensional structure of cathode materials has a great influence on the diffusion rate of lithium iron phosphate battery, especially at low temperatures. The results showed that at - 20 ℃, the discharge capacity of lithium ferrous phosphate and nickel cobalt manganese ternary batteries was only 67.38%, while that of nickel, cobalt and manganese ternary batteries was 70.1%.
5. High melting point solvent,
The electrolyte solution of lithium battery contains solvent with high melting point, which increases its viscosity at low temperature. At low temperature, the electrolyte will solidify, thus reducing its transmission speed in the electrolyte.
6. SEI film
At low temperature, the SEI film of lithium iron phosphate battery will become thinner, and the impedance of the SEI film will reduce the conductivity of lithium ions in the SEI film, thus polarizing the charge and discharge of lithium ions at low temperature, thereby reducing the charge and discharge efficiency.