Is it cobalt oxide, manganese, Lithium iron phosphate, or nickel? It’s often asked about the advantages and disadvantages of the different cell chemistries and how to choose the optimal battery.

In principle, this is similar to finding a partner in real life. It's about finding the perfect match (here energy storage and application for specific use).

In this article, we're going to talk about lithium iron phosphate batteries, and we will try to talk about some of the facts about them, like when did we start using them, in what shapes do they come, and their voltage ranges.

Key information about lithium iron phosphate batteries: short and sweet

A few facts about the lithium iron phosphate battery

Of course, it is the character traits that also play an important role in this choice of battery, but before you get to know your battery better, it's all about knowing facts about it. Knowing more will lead you to like this type of battery.

Background: 

The lithium iron phosphate battery LiFePO4, also known as LEP and LFP, belongs to the generic term lithium ions but consists of iron phosphate on the positive electrode instead of cobalt oxide as found in many other batteries. It has no cobalt in their constitution.

Age:

The first LiFePo4 batteries were developed in the late 1990s, making them one of the middle-aged members of the lithium-ion family.

Appearance: 

Iron phosphate cells come in the form of cylindrical round cells that are packed in jacketed steel cups. These are particularly common in the 18650 and 26650 designs on the market. The exact size of the battery can be read from the type designation, so an 18650 battery has a diameter of 18 mm and is 65 mm long.

If fewer curves are required, lithium iron phosphate cells are also available as flat pouch cells welded in aluminum foil or as prismatic cells that are housed in fixed housings of various sizes. These cuboid cells have screw connections on the top and can be found, for example, in buses, submarines, in the navy, or in stationary storage systems, since there can be a lot of energy for the applications in these cuboids.

Voltage range:

The nominal voltage of iron phosphate cells ranges between 3.2 to 3.3 volts, which is a bit lower than that of other lithium-ion batteries. The end-of-charge voltage is set at 3.65 volts and there are LFP cells that can be discharged to 2.0 volts. On average, however, the discharge limit is 2 to 2.5 volts.