Lithium cobalt oxide vs Lithium iron phosphate
Lithium cobalt oxide and Lithium iron phosphate are genuine alternatives to one another — a choice somebody actually makes — and differ on 3 measured properties, crystal system most clearly.
Lithium cobalt oxide vs Lithium iron phosphate
Lithium cobalt oxide
LiCoO2
The cathode that made the lithium-ion cell possible in 1980, still in the phone in your pocket, and abandoned everywhere the pack is large.
Lithium iron phosphate
LiFePO4
The cathode with no nickel and no cobalt in it — cheaper, safer, longer-lived and less energetic, and now more than half the world's cell production.
| Property | Lithium cobalt oxide | Lithium iron phosphate |
|---|---|---|
| Crystal system Categorical values can be listed side by side but not ordered or subtracted. | trigonal | orthorhombic |
| Density | 5.1 g/cm³ higher | 3.6 g/cm³ |
| Molar mass | 97.87 g/mol | 157.76 g/mol higher |
Choosing between them
Lithium cobalt oxide is recorded as a substitute for Lithium iron phosphate — stronger.
What it gives up: A third cobalt by mass, the least thermally stable of the common cathodes, and good for a few hundred cycles against LFP's thousands — which is why it survives only in the smallest cells.
In this application, on the evidence cited above.