Keyword search: battery plant ,  lithium battery factory ,  power bank works ,  lifepo4 battery mill ,  Pallet Trucks LiFePO4 Battery,  LiFePO4 Pallet Trucks Battery,  Lithium Pallet Trucks Battery, 

Lithium ion batteries have many advantages, such as high operating voltage (three times that of nickel hydrogen and nickel cadmium batteries), high specific energy (up to 165Wh/kg, three times that of nickel hydrogen batteries), small size, light weight, long cycle life, low self discharge, no memory effect, and no pollution. Lithium iron phosphate batteries are highly regarded in the new energy industry, with a cycle life of around 3000 cycles and stable discharge. They are widely used in fields such as power batteries and energy storage.
However, the speed of its promotion and the breadth and depth of its application fields are not satisfactory. In addition to factors such as price and batch consistency caused by the battery material itself, the temperature performance is also an important factor that hinders its rapid promotion. This article examines the effect of temperature on the performance of lithium iron phosphate batteries, as well as the charging and discharging behavior of the battery pack under high and low temperature conditions. 1、 Summary of room temperature cycling for individual units (modules)
The cycle life of batteries tested at room temperature shows that lithium iron phosphate batteries have the advantage of long life. Currently, they have achieved 3314 cycles, with a capacity retention rate of 90%. However, reaching 80% of the lifespan may require about 4000 cycles to terminate.
Low temperature lithium iron phosphate battery
-Charging at a low temperature of 20 ℃ and 0.5C, with a charge discharge cycle of more than 300 weeks;
-Charging at a low temperature of 40 ℃ and 0.2C, with a charge discharge cycle of over 300 weeks.
1. Monomer cycle
Currently completed: 3314cyc, with a capacity retention rate of 90%.
Due to the influence of the processing technology of the battery cells and the grouping technology of the modules, inconsistencies have already formed in the batteries after PACK completion. The more exquisite the technology, the smaller the internal resistance of the grouping, and the smaller the differences between the battery cells. The cycle life of the following modules is currently the basic data that most lithium iron phosphate can achieve. Therefore, BMS needs to regularly balance the battery pack during use, reduce the differences between battery cells, and extend the service life.
2. Module cycle
Currently completed: 2834cyc, with a capacity retention rate of 67.26%.
2、 Summary of high-temperature cycling of monomers
Accelerate the aging life of batteries under high temperature conditions.
1. Individual charge discharge curve
2. High temperature cycle
The high-temperature cycle completed 1100 cycles with a capacity retention rate of 73.8%.
3、 The influence of low temperature on charging and discharging performance
At temperatures ranging from 0 to -20 ℃, the discharge capacity of the battery is equivalent to 88.05%, 65.52%, and 38.88% of the capacity at 25 ℃, respectively; The average discharge voltage is 3.134, 2.963V, and 2.788V, respectively. The average discharge voltage at 20 ℃ is 0.431V lower than that at 25 ℃. From the above analysis, it can be seen that as the temperature decreases, the average discharge voltage and discharge capacity of lithium-ion batteries decrease, especially when the temperature is -20 ℃, the discharge capacity and average discharge voltage of the battery decrease rapidly.
Discharge curves of lithium iron phosphate batteries at different temperatures
From an electrochemical perspective, the solution resistance and SEI film resistance do not change significantly throughout the entire temperature range, and their impact on the low-temperature performance of the battery is relatively small; The charge transfer resistance increases significantly with decreasing temperature, and the temperature variation throughout the entire temperature range is significantly greater than the solution resistance and SEI film resistance. This is because as the temperature decreases, the ionic conductivity of the electrolyte decreases, and the SEI film resistance and electrochemical reaction resistance increase, resulting in an increase in Ohmic polarization, concentration polarization, and electrochemical polarization at low temperatures. On the discharge curve of the battery, this is manifested as a decrease in average voltage and discharge capacity with decreasing temperature.
After charging and discharging the battery 5 times at low temperature
From Figure 2, it can be seen that cycling 5 times at -20 ℃ and then cycling at 25 ℃ resulted in a decrease in the battery's capacity and discharge plateau. This is because as the temperature decreases, the ion conductivity of the electrolyte decreases, and the Ohmic polarization, concentration polarization, and electrochemical polarization increase during low-temperature charging, leading to the deposition of metallic lithium and the decomposition of the electrolyte, ultimately resulting in thickening of the SEI film on the electrode surface and an increase in SEI film resistance, which is manifested as a decrease in discharge plateau and discharge capacity on the discharge curve.
1. The impact of low temperature on cycling performance
0.5C rate cycling curve of lithium-ion battery at room temperature
Lithium ion battery 0.5C rate cycling curve at -10 ℃ temperature
The capacity of the battery deteriorates rapidly in an environment of -10 ℃, with only 59mAh/g remaining after 100 cycles, resulting in a capacity decay of 47.8%; Conduct charge and discharge tests on batteries that have been discharged at low temperatures at room temperature to evaluate their capacity recovery performance. Its capacity was restored to 70.8mAh/g, with a capacity loss of 68%. It can be seen that the low-temperature cycling of batteries has a significant impact on the recovery of battery capacity.
2. The impact of low temperature on safety performance
Lithium ion battery charging is the process of lithium ions escaping from the positive electrode, migrating into the negative electrode material through the electrolyte, and aggregating towards the negative electrode. One lithium ion is captured by six carbon atoms. At low temperatures, the chemical reaction activity decreases, and the migration of lithium ions slows down. The lithium ions on the negative electrode surface have not yet been embedded into the negative electrode and have already been reduced to metallic lithium, which precipitates and forms lithium dendrites on the negative electrode surface. This can easily puncture the separator and cause a short circuit inside the battery, thereby damaging the battery and causing safety accidents.
From the above data, it can be concluded that lithium iron phosphate batteries are greatly affected by temperature. In the field of power battery applications and environments with significant temperature effects, thermal management of the battery (such as air cooling, liquid cooling, etc.) is necessary to improve its efficiency and extend the service life of the battery system.

Lithium Batteries ,Ensure Quality

Our lithium battery production line has a complete and scientific quality management system

Ensure the product quality of lithium batteries

Years of experience in producing lithium batteries

Focus on the production of lithium batteries

WE PROMISE TO MAKE EVERY LITHIUM BATTERY WELL

We have a comprehensive explanation of lithium batteries

QUALIFICATION CERTIFICATE

THE QUALITY OF COMPLIANCE PROVIDES GUARANTEE FOR CUSTOMERS

MULTIPLE QUALIFICATION CERTIFICATES TO ENSURE STABLE PRODUCT QUALITY

Providing customers with professional and assured products is the guarantee of our continuous progress.

Applicable brands of our products