Analyze the important functional parameters of lithium iron phosphate power lithium-ion batteries

The working principle of lithium iron phosphate battery The full name of lithium iron phosphate battery is lithium iron phosphate battery, the name is too long, referred to as lithium iron phosphate battery. Because its function is particularly suitable for power applications, the word power was added to the title, that is, lithium iron phosphate power lithium-ion battery. Others call it a lithium-iron (life) power lithium-ion battery. Significance: In the metal market, cobalt (Co) is the most expensive, and there are few deposits, nickel (Ni) and manganese (Mn) are cheaper, and iron (Fe) is the cheapest. These positive data are also in line with the prices of these metals. Therefore, lithium batteries made of LiFePO4 anode materials should be the cheapest. Another feature of it is that it does not pollute the environment. The requirements for rechargeable batteries are: high capacity, high output voltage, excellent charge and discharge cycle function, stable output voltage, high current charge and discharge, electrochemical stable functions, safe use (no charge, discharge, short circuit, etc.), improper operation, Cause fire or explosion, wide operating temperature range, non-toxic or less toxic, no pollution to the environment. The functional requirements of choosing a lithium iron phosphate cathode lithium iron phosphate battery are good, especially when the discharge rate is large (5~10c discharge), the discharge voltage is stable, safe, will not burn, will not explode, and bear (cycle) , No pollution to the environment, it is the best, and now the best high-current output power battery. Structure and working principle: The internal structure of LiFePO4 battery is shown in Figure 1. On the left is LiFePO4 with an olivine structure, which serves as the positive electrode of the battery and is connected to the positive electrode through aluminum foil. In the middle is a barrier layer of polymer, which separates the positive and negative electrodes. Li+ ions can pass through, but e- can’t. On the right is the negative electrode of the battery, which is made of carbon (graphite) and is connected to the negative electrode of the battery with copper foil. Between the upper and lower ends of the battery is the electrolyte of the battery, and the battery is enclosed in a metal casing. When the LiFePO4 battery is charged, the lithium ion Li+ of the positive electrode moves to the negative electrode through the polymer barrier layer. During the discharge process, the lithium ions in the negative electrode move to the positive electrode through the gap. Lithium batteries are named after lithium ions move back and forth during charging and discharging. Important functions: Its rated voltage is 3.2v, the stop charging voltage is 3.6v, and the stop discharge voltage is 2.0v. Due to the different quality and craftsmanship of the positive electrode, negative electrode and electrolyte selected by various manufacturers, their performance will be somewhat different. For example, the battery capacity of the same type (battery of the same packaging specification) varies greatly (10%-20%). The important functions of lithium iron phosphate power lithium-ion battery are shown in Table 1. In order to compare with other rechargeable batteries, the characteristics of other rechargeable batteries are also listed in the table. To clarify here, lithium iron phosphate batteries processed by different manufacturers will have certain differences in various functional parameters; in addition, some functions of the battery, such as battery internal resistance, self-discharge rate, charge and discharge temperature, etc., are not included. Important functional parameters of lithium iron phosphate power lithium ion battery The capacity of lithium iron phosphate batteries varies greatly, which can be divided into three categories: small only a few tenths of a milliamp, medium only tens of milliamps, and large ones only a few hundred milliamps . Similar parameters of different types of batteries also have certain differences. The following are the parameters of the widely used small standard cylindrical lithium-iron power lithium-ion battery. Dimensions: diameter 18mm, height 650mm (18650 type). Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of digital product lithium battery charging control DC