Iron or Ion? Lithium Batteries Explained... 🔗

Are you also confused? Is it Lithium Ion or Lithium Iron? And what is LiFePO4?

A lithium-ion battery (or Li-Ion) is rechargeable kind of battery with a variety of cathodes, for example, a Lithium Nickel Manganese Cobalt Dioxide (LiNiMnCoO2) cathode for NMC batteries or a Lithium Iron Phosphate (LiFePO4) as a cathode for LiFePO4 (LFP) batteries.

LiFePO4 and NMC batteries are currently the most common lithium battery types installed in residential solar installations in the country.

A lithium-iron battery is also a rechargeable type of battery but made with Lithium Iron Phosphate (LiFePO4) as the cathode material; the “Li” is for Lithium, the “Fe” is for Iron, and “PO4” stands for phosphate (which might sound familiar if you paid attention during chemistry class ;-)).

You could say that Lithium-iron is a member of the lithium-ion battery family; A Lithium iron battery is a lithium-ion battery as well, but not every lithium-ion battery is a Lithium Iron battery.

Characteristics of LiFePO4

  • Most other Li-ion batteries have in general a higher energy density than LiFePO4 batteries, meaning that most Li-Ion batteries are lighter for the same capacity, but LiFePO4 is slowly closing the gap, for example, Tesla is now using LiFePO4 as well.
  • LiFePO4 has an edge over the Li-ion battery in chemical and thermal stability and is, therefore, safer than the other Li-ion batteries like NMC batteries. LiFePO4 batteries do not have the “thermal runaway” that can happen in other batteries, the spontaneous fire that occurred in a particular brand of phones.
  • In terms of durability, LiFePO4 is more durable than the other Li-ion batteries, e.g., NMC, as the LiFePO4 charge/discharge cycles are higher. Other Li-ion batteries have a maximum of 1,000 cycles, while LiFePO4 can be discharged for at least 4,000 cycles with many more if managed carefully.
  • Another plus for the LiFePO4 battery is that it doesn’t use Cobalt, an element that has been in the news recently, as child labour is being used to mine Cobalt.