Lithium iron phosphate (LFP) batteries are a type of lithium battery. Their full name is lithium iron phosphate lithium-ion battery, and the positive electrode material is primarily lithium iron phosphate. Because their performance is particularly suitable for power applications, they are also sometimes called "lithium iron power batteries" (hereinafter referred to as "lithium iron batteries").
The working principle of lithium iron phosphate batteries (LiFePO4)
The internal structure of a LiFePO4 battery: On the left is LiFePO4 with an olivine structure, serving as the positive electrode, connected to the battery by aluminum foil. In the middle is a polymer separator, which separates the positive and negative electrodes, allowing lithium ions (Li+) to pass through while electrons (e-) cannot. On the right is the negative electrode, composed of carbon (graphite), connected to the battery by copper foil. The electrolyte is located between the top and bottom of the battery, which is then sealed in a metal casing.
In a LiFePO4 battery, during charging, lithium ions (Li+) migrate from the positive electrode to the negative electrode through the polymer separator; during discharging, lithium ions (Li+) migrate from the negative electrode to the positive electrode through the separator. The lithium-ion battery is named for this back-and-forth migration of lithium ions during charging and discharging.
Key performance characteristics of LiFePO4 batteries
The nominal voltage of a LiFePO4 battery is 3.2 V, the termination charging voltage is 3.6 V, and the termination discharging voltage is 2.0 V. Due to differences in the quality and manufacturing processes of the positive and negative electrode materials and electrolyte materials used by different manufacturers, their performance may vary. For example, the capacity of the same model (standard battery with the same package) can differ significantly (10%–20%).
Advantages of lithium iron phosphate batteries
Compared to traditional lead-acid batteries, lithium-ion batteries have significant advantages in terms of operating voltage, energy density, and cycle life. They offer the following advantages over traditional lead-acid batteries: high energy density, strong safety, good high-temperature performance, high power output, long cycle life, light weight (saving on data center reinforcement costs), small size, long battery life, and good safety.
