LiFePO4 Batteries: A Breakthrough For Electric Vehicles

By / / 64 Comments / Uncategorized

Note: If you looking for AA-sized LifePO4, you can find them here.

Soon, we’ll probably be seeing Lithium Iron Phosphate (LiFePO4) batteries being used in most electric cars and bikes. This new battery type is set to dominate the market. Based upon lithium ion technology, LiFePO4 batteries offer many advantages over lithium cobalt dioxide (LiCoO2) batteries which are commonly used in laptops, mp3 players and cell phones.

In electric vehicles, LiFePO4 batteries offer greater range, power and safety. They provide full power until they are completely discharged, and recharge in just 2.5 hours. LiFePO4 chemistry is also environmentally friendly — it’s the least toxic of all the battery types.

A Graph Showing The Different Power Capacities and Weight of Various Batteries Types
A Graph Showing The Energy Density Of Various Batteries Types

LiFePO4 batteries were developed by Dr. John Goodenough at the University of Texas. These batteries have seen wide acceptance recently in Asian countries, but still have not made inroads in the U. S. marketplace. However, you can find these batteries being sold on eBay for electric bikes and scooters. You can now get a 52V LiFePo4 battery for an electric bike, that will give you a 65 mile range on a single charge with 60A drain rate.

For electric vehicles and plug-in electric cars, the LiFePO4 batteries will typically perform well in temperatures up to 400-degrees F, last for 6 to 7 years at a charge-discharge cycle of over 3,000.

The biggest player in the LiFePO4 marketplace for electric vehicles, however, is A123 Systems that has teamed up with GM to develop these batteries for the Chevy Volt plug-in hybrid. Another big player is Lithium Technology Corporation who has been working with GM, Toyota and U. C. Davis to develop LiFePO4 batteries for all-electric and hybrid vehicles.

Here’s a list of all the advantages of LiFePo4 batteries:

  • Safe technology — will not catch fire or explode with overcharge
  • Over 2000 discharge cycles life compared to typically around 300 for lead acid
  • 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
  • Extremely low self discharge rate (unlike lead acid which will go flat quite quickly if left sitting for long periods)
  • Does not suffer from “thermal runaway”
  • 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

Related Posts

64 thoughts on “LiFePO4 Batteries: A Breakthrough For Electric Vehicles”

  3. Mike

    LiFePO4 is a very good choice for mega-producers like A123, and after they get out of their mega IP lawsuit and actually put some helpful products on the market there may be some main-stream availability of that Chemistry. It’s possible that this stuff will all just get tied up with GM, the military, and a few other players though. A good example of all these pro-cons is our decision to build our own cobalt batteries from scratch. We have a computer inside the battery itself that monitors each individual cell during charge and discharge to make sure everything is safe and controlled, and the power/weight/price ratios we get are absolutely fantastic. See http://www.CleanRepublic.com

    Great discussion!

  4. Mike

    LiFePO4 is a very good choice for mega-producers like A123, and after they get out of their mega IP lawsuit and actually put some helpful products on the market there may be some main-stream availability of that Chemistry. It’s possible that this stuff will all just get tied up with GM, the military, and a few other players though. A good example of all these pro-cons is our decision to build our own cobalt batteries from scratch. We have a computer inside the battery itself that monitors each individual cell during charge and discharge to make sure everything is safe and controlled, and the power/weight/price ratios we get are absolutely fantastic. See http://www.CleanRepublic.com

    Great discussion!

  8. IJ/Yang

    According to our experienced on usage of LiFePO4, to keep the balance of multi-cell in series is difficult. It is therefore we developed a new charge technology, different traditional charging method, incoporated with specicail designed IC to control the charge and discharge characteristics of LiFePO4 to gain both the maximum charging efficiency and the balance status.
    To acheieve the goal, a new concept of charger was also designed to match with our cell’s assembly structure. Our new designed charger provides several probes, different from traditional two-probe, to adapt with different applied voltage.
    By adopting this new technology, LiFePO4 battery can be run smoothly and keep balance in a good condition after long term usage.

  10. Awat

    Stop selling its advantages and tell us the truth. Im sure it is not that perfect and I have seen some of the disadvantages listed in other sites, yet there is none here.

  21. Bruce Dillahunty

    Rob,

    There are more of them out there than you expect. I was surprised to learn that electric “launches” (river boats and the like) were pretty popular around the beginning of the 20th century, before internal combustion really got going.

    Funny how somethings come back around 🙂

  25. Talia

    Sounds good but what do u think of biofuel?
    Fuel the Film
    The dependence on foreign oil, especially in the recent Bush administration, hurts the U.S. economy with the roaring gas prices. That in turn affects food prices and many more. Why rely on oil? I found an amazing movie which explains all these issues very clearly, and I highly recommend watching it… and showing it at work, school, or anywhere there are large groups of people. It truly raises awareness of global warming, 9/11, and how we can turn to alternative fuel such as biofuel to save costs and moreover, combat the impeding destruction of the environment. Biofuel does not put C02 into the atmostphere like gasoline.. which causes global warming!
    http://www.myspace.com/fuelthefilm

  27. Ben Foote

    I appreciate the excitement about Lithium Phosphate batteries, but this article contains a few incorrect statements. First of all, I work at a major Lithium battery producer in the US as a development engineer. We are developing this very type of battery.

    The reason why it ‘appears’ as though you can recharge in 15 minutes is because Lithium Phosphate batteries have a FLAT voltage curve. This means that you can’t have any clue as to what state-of-charge they are in for 90% of their capability.

    Lithium Phosphate batteries have much less capacity than Lithium Ion batteries and are absolutely only preferred in applications where the battery can’t catch fire. I mean, the power to weight ratio is fairly big. Not to mention Lithium Ion batteries are much more capable in applications where high discharge and high power is needed.

    This is not a revolution in battery technology, trust me. The company I work at has relegated that they’re only useful in a select small number of applications. Lithium Ion are perfectly safe when coupled with good protection electronics and good build quality.

    I wish there was a silver bullet, but this certainly isn’t it.

  28. Dan

    Depleted Uranium is not something we want to proliferate and put in cars everywhere. Car crashes are bad enough, but when a collision results in nuclear fall-out, it’s really bad. Nuclear batteries are a great idea, but unfortunately a few bad apples could also ruin the bunch, I hate to use the “T” word, but the public is not ready for radioactive fuel sources.

  29. Ed

    This seems like a great technology. The price is a bit easier to take than traditional LION batteries. The problem with lithium though is we don’t have it here in the States, most lithium is mined in Asia.

    Firefly Energy (google them) is making a lead carbon battery that will offer performance of about 4x current lead acid batteries. I’m looking forward to putting these in my electric car.

    See it here: http://www.ZeroGasoline.com

  32. Uncle B

    Currently, the U.S. Military has total control over research for using Depleted Uranium and that includes battery development as well as H2 production. It seems wrong to exclude a known part of Science to appease the military, when we, the people, whom they supposedly serve and protect, are about to suffer terrible economic hardship, and need this knowledge to work our way out of current energy problems. Petitions are in order!

  33. Michael

    How about using this technology for AAA, AA, batteries, etc? I keep trying to use rechargeables
    but they discharge fairly fast if not used immediately after charging but even worse they seem to die many cycles before they are supposed to. I get nowhere near the 1000 to 2000 cycles advertised.
    Anyway, the market for a decent rechargeable is huge, and would save having millions of toxic batteries in landfills.

  36. Peter

    Lithium Cobalt batteries do have a better power density, but as has been mentioned, are much more unstable. It’s surprisingly easy to overload a Lithium Cobalt battery, with catastrophic results.

    A very high energy density really sounds like a great thing, more range with less need to charge, however that energy density has a downside as well. In the event of a runaway reaction, that energy WILL dissipate, and the higher the energy density, the more violent that reaction is going to be. A faulty charger, or someone trying to “hack” their charger to get better recharge times, can easily cause just this type of reaction.

    In the RC boat racing circles, it is common to use the Lithium Cobalt batteries from power tools to run the vehicles, they have a fantastic power to weight ratio and a great discharge cycle for that purpose. Unfortunately, the rapid charging and discharging done during this racing will at times cause runaway reactions. These things explode like sticks of dynamite, so a lot of people charge them inside safes so that if they do overload they will be at least somewhat contained and hopefully not hurt anyone.

    With that in mind, you are talking about a battery pack only the size of a few D cell batteries that will do significant damage when it goes off. Scale that up a little and realize that a car would have hundreds of times that amount of material that is JUST as reactive, and now instead of people containing it in a heavy casing to protect themselves, you are instead covering it with a small sheet of metal, and sitting on it, or putting your kids on top of or directly in front of it.

    The lower power density, but MUCH higher stability of Lithium Phosphate sounds pretty good in comparison, now doesn’t it?

  37. Vance

    From the article…
    “Based upon lithium ion technology, LiFePO4 batteries offer many advantages over lithium cobalt dioxide (LiCoO2) batteries which are commonly used in laptops, mp3 players and cell phones. In electric vehicles, LiFePO4 batteries offer greater range, power and safety.”

    But wait… the graph shows that these new phosphate Li-ion batteries have 60 Wh/Kg *LESS* energy output than Cobalt Li-ion? Yes, let’s all switch to these batteries so we can have “greater range, power and safety”? WTF?!?! NO.

    1. Stephen Tack

      Safety is a big advantage, but also there is the USABLE discharge cycle and recharge rate to consider.
      From what I’ve read the lifepo4 battery will provide a higher voltage for longer than standard Lion batteries… So while the energy density is lower, the usable energy capacity is similar. And the option to safely quick charge (to 90% in 15 min) would make an electric car long-range road trip similar in form to a petrol powered trip…once there are metered electric charge station avalible.

  39. Marvin

    The graph is not a typo. Lithium Cobalt batteries have a better energy density but can take less charge/discharge cycles. The other big advantage of LiFePO4 is that there is no thermal runaway which means a 20-pound ebike battery made of these cells won’t explode in your guts or burn your house down while it is charging. LiCo/Lipo (Lithium Cobalt/Lithium Polymer) batteries rarely burst into flames but the potential is there. If you want to see a bit of the potential of these batteries, look up Killacycle and watch the videos of it on the drag strip. The owner says that each run takes up about 10% of a full charge.

  40. Zoomi Scooters

    LiFePO4 just makes sense for EV’s – light, high energy density, long lasting, quick to recharge and available now. Not cheap yet, but widespread adoption should change that. I have an e-bike with a LiFePO4 battery pack and I love it.

  44. Asa

    The chart implies/shows that this battery is inferior to cobalt and all of the comparisons are to lead acid batteries. Im not seeing the advantage of this battery type.

  50. Mahmoud Kabalan

    Great new innovation!
    But the following is not an advantage for this battery alone:
    Can be connected in series for higher voltages or parallel for higher capacity.

    Its for all batteries,

    What’s really impressive is this
    Can be safely rapidly recharged — when fully discharged can be brought to a state of over 90% fully charged in 15 minutes.

    very nice!!!!
    http://www.ee-lu.com

Leave a Comment