Overview of Lithium Iron Phosphate Batteries
Lithium iron phosphate battery refers to a lithium ion battery that uses lithium iron phosphate as a positive electrode material. Lithium iron phosphate batteries have the advantages of high safety, long cycle life, rate discharge, high temperature resistance, etc., and are considered to be a new generation of lithium batteries. Juda Lithium Battery can provide customers with battery cells, BMS (power management system), and structurally integrated battery customization solutions to meet customers' personalized power needs.
1. Features of lithium iron phosphate battery
Good safety performance, no explosion when punctured, no burning and no explosion when overcharged;
Good cycle life, the cycle life of lithium iron phosphate battery can reach more than 2000 times;
Good high temperature performance, working temperature range -20°C to 70°C;
High tap density and higher capacity under the same conditions;
It can achieve 1C-5C fast charging capability, greatly shortening the charging time.
2. Application areas
Power energy storage, special equipment, robots, AGV, rail transit, medical equipment, emergency backup, power communication, etc.
Advantages of lithium iron phosphate batteries
1. Good safety performance
Safety comes from the stability of the positive electrode material and reliable safety design. The lithium iron phosphate battery pack has undergone strict safety tests and will not explode even in severe collisions.
2. Long cycle life
The 1C cycle life of lithium iron phosphate batteries generally reaches 2,000 times, or even more than 3,500 times, while the energy storage market requires more than 4,000-5,000 times, which is higher than other types of lithium batteries.
3. Good high temperature performance
The thermal peak value of lithium iron phosphate battery can reach 350~500℃, the working temperature range is wide (-20~+75℃), and 100% capacity can still be released under high temperature (60℃).
4. Fast charging
Using a special charger, the battery can be fully charged after 40 minutes of 1.5C charging.
5. Green and environmental protection
The lithium iron phosphate battery is green, non-toxic, non-polluting, has a wide range of raw material sources and is cheap.
LiFePO4 battery voltage and capacity
1. Lithium iron phosphate battery voltage
The nominal voltage of a single lithium iron phosphate battery is 3.2V, the charging voltage is 3.6V, and the discharge cut-off voltage is 2.0V. The lithium iron phosphate battery pack achieves the voltage required by the device through the series combination of the cells, the battery pack voltage=N*the number of series. Commonly used lithium iron phosphate battery pack voltages are as follows:
12V lithium iron phosphate battery
24V lithium iron phosphate battery
36V lithium iron phosphate battery
48V lithium iron phosphate battery
2. Lithium iron phosphate battery capacity
The capacity of the lithium iron phosphate battery pack is determined according to the capacity and quantity of the cells connected in parallel. Generally, it is determined according to the specific requirements of the electrical equipment. The more lithium iron phosphate cells are connected in parallel, the greater the capacity. Common lithium iron phosphate battery pack capacities are 10ah, 20ah, 40ah, 50ah, 100ah, 200ah, 400ah, etc.
LiFePO4 battery structure and working principle
1. Lithium iron phosphate battery structure
As shown in the figure, the left side is LiFePO4 with olivine structure as the positive electrode of the battery, which is connected to the positive electrode of the battery by aluminum foil, and the middle is the polymer separator, which separates the positive electrode from the negative electrode, but the lithium ion Li+ can pass through while the electron e- cannot. Pass, on the right is the negative electrode of the battery composed of carbon (graphite), which is connected to the negative electrode of the battery by a copper foil.
The working principle of lithium iron phosphate battery
When LiFePO4 batteries are charged, the lithium ions Li+ in the positive electrode migrate to the negative electrode through the polymer separator; during the discharge process, the lithium ions Li+ in the negative electrode migrate to the positive electrode through the separator. Lithium-ion batteries are named after lithium ions migrate back and forth during charging and discharging.
LiFePO4 battery charger
1. LiFePO4 Battery Charging
It is recommended to use the CCCV charging method for charging the lithium iron phosphate battery pack, that is, constant current first and then constant voltage. The constant current is recommended to be 0.3C. Constant pressure recommends 3.65.
2. Are lithium iron phosphate batteries the same as lithium ion battery chargers?
The charging methods of the two batteries are constant current and then constant voltage (CCCV), but the constant voltage points are different.
The nominal voltage of the lithium iron phosphate battery is 3.2V, and the charge cut-off voltage is 3.6V.
The nominal voltage of ordinary lithium batteries is 3.6V, and the charge cut-off voltage is 4.2V.
3. Use solar energy to charge lithium iron phosphate batteries
The solar panel cannot directly charge the lithium iron phosphate battery, because the voltage of the solar panel is unstable, it cannot directly charge the lithium iron phosphate battery, a voltage regulator circuit is required, and a corresponding lithium iron phosphate battery charging circuit is required. to charge.
4. Use the generator to charge the lithium iron phosphate battery
The generator cannot directly charge the lithium iron phosphate battery, because the electricity from the generator is alternating current or pulsed direct current, and the charging of the lithium iron phosphate battery must be regulated direct current.
