Iron phosphate batteries are actually lithium iron phosphate batteries. Lithium iron phosphate (LiFePO4) is a rechargeable lithium chemistry that uses a liquid electrolyte. This makes lithium iron phosphate batteries just another type of lithium ion batteries. Like the other numerous lithium ion chemistries, iron phosphate comes with its own benefits in certain attribute areas over other chemistries.
The two greatest strengths of iron phosphate are in the areas of number of useful cycles and inherent safety. Lithium iron phosphate (LiFePO4) charges at a lower voltage than other lithium ion chemistries and therefore does not see the level of electrolyte break-down that occurs at those higher potentials. This significantly increases the cycle life of the cell or battery. Standard lithium ion chemistries typically have a useful life of 300-500 cycles, where iron phosphate has been known to reach 3000 cycles with typical life expectancy to be greater than 1500 cycles. Iron phosphate also does not exothermically react to high temperature exposure meaning it does not go into thermal runaway like other lithium ion cell chemistries making it much safer during reasonable foreseeable misuse such as short circuiting and accidental over charging, should primary protection methods fail.
If energy density and high rate discharge capability are the main requirements of an application, other lithium ion chemistries should be considered as iron phosphate is not as beneficial in those attribute areas.
