Lithium iron phosphate

Lithium iron phosphate (LiFePO₄) is a compound used in lithium iron phosphate batteries (related to Li-Ion batteries). It is targeted for use in power tools, electric vehicles and some laptops.

Most lithium batteries (Li-ion) used in 3C (computer, communication, consumer electronics) products are mostly lithium cobalt oxide (LiCoO₂) batteries. Other lithium batteries include lithium manganese oxide (LiMn₂O₄), lithium nickel oxide (LiNiO₂), and lithium iron phosphate (LFP). The cathodes of lithium batteries are made with the above materials, and the anodes are generally made of carbon.

Avoiding the lithium cobalt oxide cathode leads to a number of advantages. LiCoO₂ is one of the more expensive components of traditional li-ion batteries, giving LFP batteries the potential to ultimately become significantly cheaper to produce. LiCoO₂ is also toxic, while lithium iron phosphate is not. LiCoO₂ also can lead to problems with runaway overheating and outgassing, making batteries that use it more susceptible to fire than LFP batteries. This advantage means that LFP batteries don't need as intense charge monitoring as traditional li-ion. Lastly, LFP batteries tend to have superior power density in comparison to traditional li-ion.

LFP batteries also have their drawbacks. There are ongoing international patent suits regarding this technology, and mass production with stable and high quality still faces many challenges. The current low production levels mean that LFP batteries tend to cost more than their LiCoO₂ equivalents. The energy density of LFP batteries is significantly lower than LiCoO₂ (although well higher than its main competitor for safety and lifespan, the nickel-metal hydride battery), and the market acceptance for large batteries is rather low in certain applications, making LFP batteries harder to commercialize.

Example application

China pushed for cleaner air ahead of the Olympics by ordering electric buses for transport at the games and in the city of Beijing. The technology chosen was originally hydrogen battery fuel cells but was changed to LiFePO₄ in order to meet critical path milestones of the contract, and costs. The system battery voltage has been set at 360 VDC with a variety of energy capacities depending on the route of the particular bus. Ranges are expected to be 150 to 300 kilometers per charge. Lithium powered buses offer a solution to the growing air pollution in the cities in and around the more developed China harbor area, and the Olympic village.

ee also

*Lithium iron phosphate battery