The full name of lithium iron phosphate battery is lithium iron phosphate lithium ion battery, the name is too long, referred to as lithium iron phosphate battery. Because its performance is particularly suitable for power applications, the word "power" is added to the name, namely lithium iron phosphate power battery. Some people call it "LiFe (LiFe) power battery".
In the metal trading market, cobalt (Co) is the most expensive, and storage is not much, nickel (Ni), manganese (Mn) is cheaper, and iron (Fe) is the cheapest. The price of the cathode material is also consistent with the price of these metals. Therefore, a lithium ion battery made of a LiFePO4 positive electrode material should be the cheapest. Another feature of it is that it is environmentally friendly.
The requirements for rechargeable batteries are: high capacity, high output voltage, good charge and discharge cycle performance, stable output voltage, high current charge and discharge, electrochemical stability, and safety during use (no overcharge, over discharge, and short circuit) Such as improper operation caused by burning or explosion), wide operating temperature range, non-toxic or less toxic, no pollution to the environment. Lithium iron phosphate battery using LiFePO4 as positive electrode has good performance requirements, especially in large discharge rate discharge (5~10C discharge), stable discharge voltage, safety (no combustion, no explosion), and life (cycle number) ), it is the best for the environment, it is the best high current output power battery.
Structure and working principle
The internal structure of the LiFePO4 battery is shown in Figure 1. On the left is the olivine-structured LiFePO4 as the positive electrode of the battery. The aluminum foil is connected to the positive electrode of the battery. The middle is the polymer separator. It separates the positive electrode from the negative electrode, but the lithium ion Li+ can pass and the electron e- cannot pass. The right side is composed of A battery negative electrode composed of carbon (graphite) is connected to the negative electrode of the battery by a copper foil. Between the upper and lower ends of the battery is the electrolyte of the battery, and the battery is hermetically sealed by a metal casing.