The Lithium Iron Phosphate (LiFePO4) batteries are based on Lithium Ion, but they offer many advantages over LiCO2 (Lithium Cobalt), frequently used in laptops, mp3 players and cell phones. They also offer a greater range, power and safety, in an electric vehicle – they will not explode or catch fire if overcharged.
LiFeO4 have fast charging rates and can be used until they are fully discharged, unlike their NiMH, Li-Ion or LiCO2. Also, they’re the least toxic of all their “sisters”.
Compared to a lead-acid battery, that you can only charge 300 times, LiFePO4 can endure many more discharge cycles (>2000). You can leave them standing for a long time, and they will not discharge, nor will they lose energy by thermal effect.
Other properties of LiFePO4 batteries are:
- Double the usable capacity of similar amp hour lead acid batteries
- Virtually flat discharge curve means maximum power available until fully discharged (no “voltage sag” as with lead acid batteries)
- High discharge rate capability, 10C continuous, 20C pulse discharge
- Unlike lead acid batteries, can be left in a partially discharged state for extended periods without causing permanent damage
- Can be used safely in high ambient temperatures of up to 60C without any degradation in performance
- Maintenance free for the life of the battery
- Can be operated in any orientation
- Does not contain any toxic heavy metals such as lead, cadmium, nor any corrosive acids or alkalies thus making LiFePO4 batteries the most environmentally friendly battery chemistry available
- LiFePO4 cells are of solid construction – there are no fragile/brittle plates made of lead which can be prone to failure over time as a result of vibration
- Can be safely rapidly recharged – when fully discharged can be brought to a state of over 90% fully charged in 15 minutes
The American market, even if it’s mature at the energy storage chapter, didn’t welcome these batteries, even if they were invented by an American. Still, GM has allied with A123 and Lithium Technology Corporation to put these battery into the Chevy Volt.
This news is interesting enough to keep our attention towards the electric future of vehicles, even if others fight hardly to invent new types of biodiesel and “bio”-engines. There are greener than their grandfathers, but cannot last in the long run. Electricity is starting to be the new way of moving around.