Will Future Tesla Electric Cars Use Metal-Air Batteries?

Follow John

2013 Tesla Model S

2013 Tesla Model S

Enlarge Photo

Most advocates and industry analysts expect lithium-ion batteries to dominate electric-car energy storage for the rest of this decade.

But is Silicon Valley startup carmaker Tesla Motors [NSDQ:TSLA] planning to add a new type of battery to increase the range of its electric cars?

The high-end 2013 Tesla Model S with an 85-kilowatt-hour lithium-ion battery pack is EPA-rated at 265 miles of range.

(Real-world range can be lower, depending on a number of factors, including temperature, speed, and driving style.)

8 patent applications

But as a commenter on the Tesla Motors forum and a recent article on the stock investing site SeekingAlpha have noted, Tesla has filed for eight separate patents on uses of metal-air battery technology.

Take, for instance, "Efficient Dual Source Battery Pack System for an Electric Vehicle," which is Tesla's patent application # 20120041625.

Two of the three names on the application are JB Straubel, Tesla's chief technical officer, and Kurt Kelty, its lead battery engineer.

The metals covered for use in the metal-air battery are aluminum, iron, lithium, magnesium, vanadium, and zinc.

First and second battery packs

The application's abstract includes the following summary:

A method of optimizing the operation of the power source of an electric vehicle is provided, where the power source is comprised of a first battery pack (e.g., a non-metal-air battery pack) and a second battery pack (e.g., a metal-air battery pack).

The power source is optimized to minimize use of the least efficient battery pack (e.g., the second battery pack) while ensuring that the electric vehicle has sufficient power to traverse the expected travel distance before the next battery charging cycle.

Tesla Motors - Model S lithium-ion battery pack

Tesla Motors - Model S lithium-ion battery pack

Enlarge Photo

In other words, a presumably lithium-ion pack for everyday use and a supplemental metal-air battery for longer range when needed.

Another patent application, Electric Vehicle Extended Range Hybrid Battery Pack System, says:

The second battery pack may be used to charge the first battery pack or used in combination with the first battery pack to supply operational power to the electric vehicle.

1,000 miles of range

Metal-air batteries, some of which slowly consume their anodes to give off energy, hit the news last month when Israeli startup Phinergy demonstrated its prototype battery and let reporters drive a test vehicle fitted with the energy-storage device.

Mounted in a subcompact demonstration car, Phinergy's aluminum-air battery provides 1,000 miles of range, it said, and requires refills of distilled water (which acts as electrolyte in the cells) about every 200 miles.

Diagram from Tesla Motors patent application for dual battery packs including metal-air battery

Diagram from Tesla Motors patent application for dual battery packs including metal-air battery

Enlarge Photo

Once the aluminum plates are consumed, they must be replaced--a task Phinergy didn't discuss in any detail.

Production in 2017?

Phinergy CEO Aviv Tzidon told Bloomberg reporter Elliott Gotkine last month that his company has signed a contract with a global automaker to deliver the battery in production volumes, starting in 2017.

He didn't name the company, and Tesla does not say much about its future products (occasional tweets from its CEO Elon Musk aside).

But for Tesla, combining the acceleration provided by a lithium-ion battery with the longer range offered by a consumable aluminum-air battery might permit future vehicles that offer the responsiveness of the Model S with even longer range when needed.

We can dream, anyhow.


Follow GreenCarReports on Facebook and Twitter.

Follow Us

Comments (41)
  1. Exciting times. Sooner or later, one of these moonshots is going to come to fruition. It can't come soon enough.

  2. Woo hoo!!! I wonder what Chevron-Texaco will do to try and buy up this patent. $30 million for the last one will be chump change.

  3. There are many limitations from this technology. First of all, it needs water, distilled water in fact. i know some cities that struggle to supply enough drinking water for its population. Also, im not sure that consumming O2 of air is a good idea, unless it's returned to the environment sometime. Finally, after the 1000 miles they say it can do, the plates must be replaced... Would you pay for an oil change every 1000 miles?

  4. Yes, water is scarce and oil covers 70% of the earth's surface and falls from the sky. Did I get that backwards?

  5. BAckwards, LOL, no Rick that sounds about right. But you forgot to mention, a glass of water averages about 30 minutes and $40 dollars, and an oil change is immediate and free! And for heavans sake stop breathing, you might cause a catastrophic loss of oxygen.

  6. there are many things to consider with this. Would you pay for an oil change every 1000 miles---considereing I did not pay for the gas to propel me that distance then possibly. If the plate change is as easy as replacing an air filter--yes.

  7. You did not read the post with understanding - how often you travel more then 260 miles in one day?Those metal air batteries would be for backup mainly as current batteries would be used and recharged.So you might have to change them every 10k or 20k miles.

  8. So even though you'll get a longer range you'll have to stop for water every 200 miles. You'll get 1000 miles of range but you'll have to stop for water 5 times to do 1,000 miles. And the metal-air battery will be disintegrating its self so your going to require more maintenance diluting the electric car perk of low maintenance. It sound like another weird way of hurrying to achieve higher range rather then giving batteries a chance to evolve. Bad idea.

  9. Most people need to stop for a bathroom break every 3 hours.

  10. Perfect opportunity for a quick charge if you ask me!

  11. Perhaps. Though I wouldn't mind taking a sip of water, and pouring the rest in with the electrolytes.

    Right now early adopters are excited about rheir EV's, charting their trips and giving their vehicles nicknames. Imagine how much more bonding would occur if their now air breathing vehicles, stopped for breaks to share a sip of electrolyte refreshing water with their owners.

  12. Yeah we might even start procreating to produce the next generation ;-}

  13. True but you have to admit, this ads complexity to the electric car, and one of the big bonuses is supposed to be simplicity. And we're going to need yet another type of infrastructure to support this. Not that getting distilled water is hard but you'd have to come up a way to get it into the car while your out. So your going to have to stop somewhere to pump water in, it'll be the same as stopping for gas.

  14. Above comment was @ Doug

  15. Phinergy's system certainly seems high cost and high maintenance but all sorts of energy storage systems are being developed that are better suited for secondary backup/range extender use than primary traction applications. Guess Tesla wants to be prepared if anything practical ever comes to fruition so it could be integrated with its battery architecture.

  16. Does anyone know how much water is required for these batteries? I mean, if it's like a couple of gallons, couldn't they just put a small tank filled with water? It's hard to imagine that this would require a massive amount of water to make this work. And even if it did, fortunately we have an infrastructure for water. :)

  17. There are more comments in this thread
  18. Or, one battery-pack that has fast charge and discharge properties for acceleration and regen+ the second battery-pach with batteries with higher energydensity that tricklecharge first one! In this way putting les strain on the 2nd one! The 2nd battery being a bit like the engine in an "oldfashioned" hybrid ;-)

  19. I think this is interesting as a back up plan, as Tesla details in their application. It would be like having range extending cartridges that you could use and then replace.

  20. Not metal air battery; metal air fuel cell! This doesn't store electricity but produces it by oxidizing metal which means there is likely to be substantial cost involved in using this type of fuel cells as range extender as they need to be refurbished regularly. No doubt Tesla likes to have its bases covered but I doubt Phinery's impractical proposal of a system that needs adding water and replacing aluminum plates every thousand miles is a serious alternative for the supercharging network.

  21. it didn't mention replacement schedule. Likely to be 10 to 20,000 miles, not that that is good.

  22. The pack tested by Phynergy contained 50 aluminum plates good for 20 miles each. That means overhaul after 1000 miles.

  23. And tesla patent, if you will read it carefully states for those to be used as secondary pack - when you run out of your daily 260 mile range - I wonder how often you drive more then this.Plus you should still use tesla superchargers on long trips whenever possible.

  24. 10,000 miles? Not necessarily Doug. I have about 40 miles of range with my Volt. I replace the non renewable fuel (3 or 4 gallons of gasoline) at about 2200 miles. If I had 250 miles battery range and 1000 miles of range extending charge, I'm very certain folks in my situation would get a lot more than 10,000 miles before replacing their non-renewable plates.

  25. So this is a single use battery as backup for the rechargeable. Right?

    I am guessing this all comes down to economics. If replacing the single use battery is cheap enough, it might be useful for once or twice a year of emergency use. However, if the battery is really expensive, no one would ever dare use it.

    If it is cheaper to be towed and spend the night in a hotel, the backup battery will probably never get used.

  26. This is encouraging news really. If ever there was a company that truly has a dog in this fight, it's Tesla. And the fact that they have made the effort to score patents on several metal-air battery concepts shows
    1. Seriousness about the potential for metal-air batteries.
    2. Protection of intellectual property surrounding metal-air batteries.
    3. Tesla is working on these technologies in earnest, maybe even as we speak.

    I've read that IBM is working on Lithium Air, and Toyota is working on Zinc Air as well as solid state batteries, however this is the first I've seen actual patents being pursued. Perhaps this will make a few other companies a little more ambitious.

  27. It's interesting to see the innovation that takes place from Tesla and the slowness of innovation from Nissan. Tesla takes the greater risks and looks for long range profits; and, in the process leads the marketplace. Nissan follows because it is ever aware of the necessary short term profit motive that feeds Wall Street Greed, so doesn't take the risks...Tesla will be more successful in the long run as a result.

  28. Quite the other way around I imagine. Nissan has deep pockets and can keep up the loss leader game for quite a while, Tesla is knee deep in debt and needs to show profit soon.

    These patent applications don't seem to be related to expensive long term energy storage device developments by Tesla itself though, only to ways to incorporate certain third party metal air battery and/or fuel cell ideas into their battery architecture.

  29. It really depends on the cost to manufacture the air battery/fuel cell. Presumably they are thinking of it as a range extender for those occasional long trips. So, it has to be cheaper than renting a car and paying for the gasoline. Then the question is can you refurbish or recycle?

  30. Yes, you can - http://www.phinergy.com/

  31. I hope not. I think the metal-air battery idea is a loser: huge usage of metal, which costs much energy to refine; and the large amount of waste product that must be recycled.

    Tesla, DON'T go there.

    Non-consumable metal air batteries such as lithium air batteries, sure, but don't go with consumable batteries.

  32. Since we have been doing those patent ideas in EV's for decades I don't se how they can be enforced.

    Metal/Air is a great, proven tech that suffers from the chicken or egg problem. They need EV's that use them which won't be built until there are battery stations.

    But Musk can do both just adding them to supercharging stations and in under 1 minute the machine changes the battery for another 500-1000 miles.

    I think they are doing it in Israel where the compact country makes it easier to do.

  33. There are huge problems with ...air batteries. They consume materials that take huge fossil fuel investments. Aluminum uses huge amounts of electricity, that is where the energy for the battery comes from. Distilled water takes huge energy too, this is not rain water. Keep the technological advances of the lithium chemistry coming, figure out the problems of ultra capacitors.

  34. makes me wonder if the high cost of cars is the technology or the legal costs of protecting all these patents?

  35. Reading the comments John Voelcker's clever linking of the patent applications to an earlier report about Phinergy's aluminum-air fuel cell seems to have caused quite some confusion. This is not about Tesla seriously contemplating using a specific metal air battery or fuel cell like Phynergy's, this is just about Tesla covering its bases in case any sort of energy storage device that's only suitable for secondary/ range extender purposes rather than primary traction battery ever comes to fruition so it has the technical/legal framework in place to integrate it into its battery system.

  36. @Chris: Nicely put. Thanks. As you say, I used Phinergy as an illustrative example, not *the* direction that Tesla is going. That's why the headline specifically does NOT say "1,000-Mile Tesla" or some such.

  37. Of course there are already kits on the market, one can assemble their own metal-air battery powered vehicle: http://www.thamesandkosmos.com/products/construction/ebv.html


  38. Great article John. I always believed that a 2 battery type system may be in the works eventually for all traction batteries. Take the best from both.

  39. I think the air/metal idea is very interesting and dissenters are prematurely ruling out an idea that's still in its infancy.

    However, the most interesting idea in this article is of a secondary/replaceable car battery.

    Car makers would be far more capable of producing a no-compromise electric car if they could build in only regularly-used range and provide rarely-used range via a secondary battery that plugs into the car and charges the primary battery while in use a la the Mophie iPhone case. Why reduce efficiency by always carrying additional battery weight when you could simply toss it in whenever needed and potentially swap out at Tesla stations as you go?

    You wouldn't even need to recharge. Just swap out and charge while you drive!

  40. The Lithium-air battery will be used only as a range extender. Tesla's tech uses the rechargeable type that does NOT consume oxygen. It inhales on charge and exhales on discharge.

  41. Making a beer can is really rather complicated. The consistent thickness and stamping the lid with the little opener is no small feat to do at the incredible production volumes. If a metal-air battery needs nothing more than aluminum plates, air and distiller water, I just don't see how anyone could think the technology does not have potential.

Commenting is closed for old articles.

Get FREE Dealer Quotes

From dealers near you

Find Green Cars


© 2015 Green Car Reports. All Rights Reserved. Green Car Reports is published by High Gear Media. Send us feedback. Stock photography by izmo, Inc.