News
We are professional, we are confident, we do better
Current Position:
Homepage
/
/
/
The influence of temperature on lithium iron phosphate battery was deeply analyzed

The influence of temperature on lithium iron phosphate battery was deeply analyzed

  • Categories:Industry news
  • Author:
  • Origin:
  • Time of issue:2022-05-12 15:47
  • Views:

(Summary description)As can be seen from the cycle life of the battery tested at room temperature, lithium iron phosphate battery has the advantage of long life. At present, it has reached 3,314 cycles, and the capacity retention rate is still 90%, while it may take about 4,000 times to reach 80% of the life termination.

The influence of temperature on lithium iron phosphate battery was deeply analyzed

(Summary description)As can be seen from the cycle life of the battery tested at room temperature, lithium iron phosphate battery has the advantage of long life. At present, it has reached 3,314 cycles, and the capacity retention rate is still 90%, while it may take about 4,000 times to reach 80% of the life termination.

  • Categories:Industry news
  • Author:
  • Origin:
  • Time of issue:2022-05-12 15:47
  • Views:
Information

Lithium ion battery has high working voltage (nickel metal hydride, nickel cadmium battery 3 times), large specific energy (up to 165Wh/kg, nickel metal hydride battery 3 times), small size, light weight, long cycle life, low self-discharge, no memory effect, no pollution and many other advantages. In the new energy industry, lithium iron phosphate battery is promising, the battery cycle life can reach about 3000 times, stable discharge, is widely used in power batteries and energy storage and other fields. However, the speed of its promotion and the breadth and depth of application field are not satisfactory. In addition to price and batch consistency caused by battery materials, temperature performance is also an important factor hindering its rapid promotion. The effect of temperature on the performance of lithium iron phosphate battery and the charging and discharging conditions of the battery pack at low and high temperatures were investigated by Wifeng Electronics. Huai Feng electronics and we discuss the influence of temperature lithium iron phosphate battery.
One, monomer (module) room temperature cycle summary
As can be seen from the cycle life of the battery tested at room temperature, lithium iron phosphate battery has the advantage of long life. At present, it has reached 3,314 cycles, and the capacity retention rate is still 90%, while it may take about 4,000 times to reach 80% of the life termination.
Due to the influence of cell processing technology and module grouping technology, inconsistency has been formed after the battery PACK is completed. The more exquisite the technology is, the smaller the internal resistance of the group will be, and the smaller the difference between cells will be. The cycle life of the following modules is the basic data that most lithium iron phosphate can achieve at present. In this way, BMS is required to balance the battery pack regularly in the process of use to reduce the difference between cells and extend the service life.
Two, low temperature on the performance of charge and discharge
At the temperature of 0 ~ -20℃, the discharge capacity of the battery is 88.05%, 65.52% and 38.88% of the discharge capacity of the battery at the temperature of 25℃. The average discharge voltage is 3.134 V, 2.963 V and 2.788 V respectively. The average discharge voltage at 20℃ is 0.431 V lower than that at 25℃. From the above analysis, it can be seen that with the decrease of temperature, the average discharge voltage and discharge capacity of lithium-ion batteries are reduced, especially when the temperature is -20℃, the discharge capacity and discharge average voltage of batteries decline rapidly.
From the Angle of electrochemical analysis, the solution resistance and SEI film resistance have little change in the whole temperature range, and have little influence on the low temperature performance of the battery. The charge transfer resistance increases significantly with the decrease of temperature, and is significantly greater than the solution resistance and SEI film resistance in the whole temperature range. This is because with the decrease of temperature, the ionic conductivity of the electrolyte decreases, and the SEI film resistance and electrochemical reaction resistance increase accordingly, leading to the increase of ohmic polarization, concentration polarization and electrochemical polarization at low temperature. On the discharge curve of the battery, it is shown that the average voltage and discharge capacity decrease with the decrease of temperature.
After five cycles at -20℃ and then at 25℃, the capacity and discharge platform of the battery were reduced. This is because with lower temperature, the ionic conductivity of electrolyte is reduced, the low temperature charging in the process of the ohm polarization, concentration polarization and electrochemical polarization increase, lead to lithium metal deposition, the electrolyte decomposition, eventually lead to thickening of the SEI film electrode surface, the SEI film resistance increases, the discharge curve of discharge platform and reduce discharge capacity.
1. Influence of low temperature on cycle performance
The capacity of the battery decays rapidly at -10℃. After 100 cycles, the capacity only remains 59mAh/g, and the capacity decays by 47.8%. Charge and discharge test of the battery under low temperature at room temperature, and the capacity recovery performance of the test period. Its capacity was restored to 70.8mAh/g, a loss of 68%. It can be seen that the low temperature cycle of the battery has a great influence on the recovery of the battery capacity.
2. Influence of low temperature on safety performance
Lithium-ion battery charging is a process in which lithium ions are removed from the positive electrode through electrolyte migration and embedded in the anode material. Lithium ions polymerize to the negative electrode, trapping one lithium ion from six carbon atoms. At low temperature, the chemical reactivity decreases and the migration of lithium ions slows down. Lithium ions on the surface of the negative electrode have been reduced to lithium metal before being embedded in the negative electrode and precipitated out to form lithium dendrites on the surface of the negative electrode, which is easy to Pierce the diaphragm and cause short circuit in the battery, thereby damaging the battery and causing safety accidents.
It can be concluded from the above data that lithium iron phosphate battery is greatly affected by temperature. In the application field of power battery and the application environment with great influence of temperature, it is necessary to carry out thermal management (air cooling, liquid cooling, etc.) to improve the efficiency of battery and prolong the service life of battery system.

Scan the QR code to read on your phone

If you recognize Fyoda's brand, technology, products and market prospects,

We look forward to establishing a strategic partnership with you for win-win cooperation and development!

Product Center

Contact Details

这是描述信息

24-hour service hotline

Tel: 13418697882 (Mr. Li)
E-mail:
lcq@cell-solar.com

Address: Building 4, No. 28, Tianshan Road, Xinbei District, Changzhou

这是描述信息

WeChat

这是描述信息

Mobile Station

Copyright © 2022  Changzhou Fyoda Intelligent Equipment Technology Co., Ltd.    苏ICP备*********号-1