Lithium Iron Phosphate Battery Working Principle

Lithium Iron Phosphate Battery Working Principle

Lithium iron phosphate battery refers to lithium ion battery which uses lithium iron phosphate as cathode material. The cathode materials of lithium ion batteries mainly include lithium cobalt acid, lithium manganese acid, lithium nickel acid, ternary materials, lithium iron phosphate and so on. Lithium cobalt acid is the cathode material used in most lithium ion batteries. In terms of material principle, lithium iron phosphate is also an embedding and deembedding process, which is exactly the same as lithium cobalt acid and lithium manganese acid.

Lithium iron phosphate battery belongs to lithium ion secondary battery, one of the main uses is for power battery, compared with Ni-MH, NI-CD battery has a great advantage.

The charging and discharging efficiency of lithium iron phosphate battery is higher than 90% in the case of rate discharge, while that of lead-acid battery is about 80%.

Safety Improvement

The P-O bond in lithium iron phosphate crystal is stable and difficult to decompose. Even at high temperature or overcharge, it will not collapse and heat or form strong oxidizing substances like lithium cobalt acid, so it has good safety. Some reports have pointed out that in the actual operation, a small number of samples were found to burn in the acupuncture or short-circuit experiments, but no explosion occurred. In the overcharging experiment, the explosion was still found when the high-voltage charging was much more than several times the self-discharge voltage. However, the overcharge safety of the battery is much improved compared with the ordinary liquid electrolyte lithium cobalt acid battery.

Improvement In Lifespan

Lithium iron phosphate battery refers to lithium ion battery which uses lithium iron phosphate as cathode material.

The cycle life of long life lead-acid battery is about 300 times, the highest is 500 times, while the cycle life of lithium iron phosphate battery is more than 2000 times, and the standard charge (5 hours rate) can reach 2000 times. Lead-acid batteries of the same quality are "new half a year, old half a year, maintenance and maintenance for another half a year", at most 1~1.5 years, and lithium iron phosphate batteries used under the same conditions, the theoretical life will reach 7~8 years. All in all, the performance price is more than four times that of lead-acid batteries in theory. High current discharge can high current 2C fast charge and discharge, under the special charger, 1.5C charge within 40 minutes can make the battery full, starting current up to 2C, and lead-acid battery has no such performance.

Good High Temperature Performance

The peak electric temperature of lithium iron phosphate can reach 350℃-500℃, while lithium manganate and lithium cobalt acid are only about 200℃. The operating temperature range is wide (-20C -- +75C), with high temperature resistance characteristics of lithium iron phosphate electric heating peak can reach 350℃-500℃, while lithium manganate and lithium cobalt acid only in about 200℃.

High Capacity

Has a larger capacity than ordinary batteries (lead acid, etc.). The monomer capacity is 5AH-1000AH.

No Memory Effect

When a rechargeable battery is constantly full, its capacity quickly falls below its rated capacity. This phenomenon is called memory effect. For example, nickel-metal hydride and nickel-cadmium batteries have memory, but lithium iron phosphate batteries do not have this phenomenon. No matter what state the battery is in, it can be used with charging, without first putting out and then charging.

Light Weight

The VOLUME of lithium iron phosphate battery with the same specification capacity is 2/3 of the volume of lead-acid battery, and the weight is 1/3 of lead-acid battery.

Environmental Protection

But some experts say that the environmental pollution caused by lead-acid batteries mainly occurs in the non-standard production process and recycling process of enterprises. Similarly, lithium batteries belong to the new energy industry is good, but it can not avoid the problem of heavy metal pollution. Lead, arsenic, cadmium, mercury, chromium, etc. may be released into dust and water during metal material processing. Battery itself is a kind of chemical substance, so it may produce two kinds of pollution: one is the pollution of process waste in the production engineering; Second, the battery pollution after scrapping.

Lithium iron phosphate battery also has its disadvantages: for example, the low temperature performance is poor, the positive electrode material vibration density is small, the volume of lithium iron phosphate battery with the same capacity is larger than lithium ion battery such as lithium cobalt acid, so it does not have advantages in the aspect of micro battery. When it comes to power batteries, lithium iron phosphate batteries, like other batteries, face the problem of battery consistency.

Power Battery Comparison

At present, the most promising cathode materials for power type lithium ion batteries mainly include modified lithium manganese (LiMn2O4), lithium iron phosphate (LiFePO4) and lithium nickel-cobalt manganese (Li(Ni,Co,Mn)O2) teramaterials. Nickel-cobalt lithium manganate ternary materials are generally considered to be difficult to become the mainstream of power lithium ion batteries for electric vehicles due to the lack of cobalt resources, the high price fluctuation of nickel and cobalt and other reasons, but can be mixed with spinel lithium manganate in a certain range.

Industry Application

Carbon coated aluminum foil brings technological innovation and industrial promotion for lithium industry; Improve the performance of lithium electric products and improve the discharge rate.