The structure and working principle of lithium iron phosphate battery?

Introduction to Lithium Iron Phosphate Battery Lithium iron phosphate battery refers to a lithium ion battery that uses lithium iron phosphate as the positive electrode material. The cathode materials of lithium-ion batteries mainly include lithium cobaltate, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate and so on. Among them, lithium cobalt oxide is currently the cathode material used in most lithium-ion batteries. Lithium iron phosphate battery structure and working principle The internal structure of LiFePO4 battery is shown in Figure 1. On the left is LiFePO4 with olivine structure as the positive electrode of the battery. It is connected to the positive electrode of the battery by aluminum foil. In the middle is a polymer separator, which separates the positive electrode from the negative electrode, but the lithium ion Li+ can pass but the electron e- cannot pass. The negative electrode of the battery composed of carbon (graphite) is connected to the negative electrode of the battery by 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. When the LiFePO4 battery is charged, the lithium ion Li+ in the positive electrode migrates to the negative electrode through the polymer separator; during the discharge process, the lithium ion Li+ in the negative electrode migrates to the positive electrode through the separator. Lithium-ion batteries are named after lithium ions move back and forth during charging and discharging. The characteristics of lithium iron phosphate battery High efficiency output: standard discharge is 2～5C, continuous high current discharge can reach 10C, instant pulse discharge (10S) can reach 20C; good performance at high temperature: internal temperature is as high as 95 at external temperature of 65℃ ℃, the temperature of the battery can reach 160℃ at the end of the discharge, the battery structure is safe and intact; even if the battery is damaged inside or outside, the battery does not burn or explode, and the safety is the best; excellent cycle life, after 500 cycles Its discharge capacity is still greater than 95%; there is no damage after overdischarge to zero volts; it can be quickly charged; low cost; no memory effect: rechargeable batteries work under conditions that are often fully charged and not discharged, and the capacity will quickly fall below the rated capacity Value, this phenomenon is called the memory effect. Ni-MH and Ni-Cd batteries have memory properties, but lithium iron phosphate batteries do not have this phenomenon. No matter what state the battery is in, it can be charged and used at any time without having to discharge it before charging. Small in size and light in weight, the volume of the lithium iron phosphate battery of the same specification and capacity is 1/3 of the volume of the lead-acid battery, and the weight is 1/3 of the lead-acid battery. No pollution to the environment, the battery does not contain any heavy metals and rare metals (the nickel-hydrogen battery requires rare metals), non-toxic (SGS certification), no pollution, in line with the European ROHS regulations, is an absolute green battery. However, there is a large amount of lead in lead-acid batteries. If they are not handled properly after being discarded, they will still cause secondary pollution to the environment, while lithium iron phosphate materials are pollution-free in both production and use processes. The lithium iron phosphate battery assembly production process is divided into three sections, one is pole piece production, the other is battery cell production, and the third is battery assembly. In the production process of lithium iron phosphate battery assembly, pole piece production is the basis and battery cell production is the core. Battery assembly is related to the quality of the finished lithium battery.