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Batteries Faradion sodium ion battery energy storage

Published on July 29th, 2015 | by Tina Casey


UK Energy Storage Startups Take Aim At EV Battery Market

July 29th, 2015 by  

Lithium-ion is the gold standard for chemical energy storage, but a pair of UK companies have been working on alternatives that could knock down the cost of electric vehicles — and knock Li-ion out of the running. The two companies, Oxis Energy and Faradion, caught the eye of the American Chemical Society, which just gave them a huge write-up in its Chemical & Engineering News publication, so let’s take a look and see what’s up.

OXIS energy storage Li-S batteries for EVs

Oxis Energy

We were just noticing Oxis Energy, too. Earlier this summer, Oxis announced that it will be ready to bring its lithium-sulfur (Li-S) battery to market next year, and it also entered into a partnership with the home and commercial energy storage installer Anesco.

Writing for Chemical & Engineering News yesterday, Alex Scott brings us up to date. Oxis plans to “double what any lithium-ion [Li-ion] battery can deliver” within about four years, bringing the energy density of its battery cells to 500 Wh per kilogram. The near-term goal, according to the company’s website, is 400.

If Oxis can succeed in using half the material to provide the same performance as Li-ion, that would bring down the cost of an electric vehicle significantly.

The company is aiming for a cost of $125 per kWh (kilowatt-hour) in the near term. Scott does the math and arrives at a cost of $10,000 for an electric vehicle battery with a capacity of 80 kWh.

Comparisons to the much-publicized Tesla EV naturally come to mind. The last time we heard from Tesla Motors cofounder and CEO Elon Musk on the topic of EV battery costs, he was anticipating that the cost of Li-ion batteries (such as those used by Tesla) would drop to around $200 per kWh “in the near future,” while estimates have it at around $250–300/kWh today, so it seems that Oxis’s Li-S solution is looking to really compete.

Sulfur & Energy Storage

In addition to high energy density, Oxis’s Li-S cells get high lifecycle marks. As of 2012, the company was seeing cycles of more than 1,000 before capacity reduces to 80% (as in 80% beginning-of-life capacity). The most recent information on the company’s website describes the expectation of approximately 2,000 cycles to 80%.

According to Oxis, its cells have a 100% available depth-of-discharge, compared to 80% for Li-ion. Unlike Li-ion, the Oxis cell can’t be damaged by over-discharging.

Another advantage is the indefinite shelf life of the Oxis cell, compared to the periodic recharging required of Li-ion. That’s not a particular concern to most drivers, but it’s something to consider if you don’t use your car for months at a time (according to Oxis, Li-ion batteries need to recharge every few months).

Oxis also points out that by using sulfur instead of nickel, cobalt, and other heavy metals, the Li-S cell has a smaller environmental footprint than Li-ion energy storage chemistry.  The company also gets Brownie points for sourcing its sulfur by reclaiming oil refinery waste.

And, this is the bottom line for Oxis:

Sulfur represents a natural cathode partner for metallic Li and, in contrast with conventional lithium-ion cells, the chemicals processes include dissolution from the anode surface during discharge and reverse lithium plating to the anode while charging. As a consequence, Lithium-Sulfur allows for a theoretical specific energy in excess of 2700Wh/kg, which is nearly 5 times higher than that of Li-ion.


Faradion also sailed across CleanTechnica’s radar this year, when it demonstrated a sodium-ion battery on an electric bicycle. That’s a big deal because, while sodium-ion energy storage is proven technology, until now it has been considered too bulky for use in electric vehicles.

Scott has this to say about the Faradion sodium-ion battery:

Faradion has made a sodium-ion battery with an energy density—a measure of how much power can be packed into a battery cell—of 140 to 150 watt-hours per kilogram.This compares with about 170 Wh per kg for lithium-ion cells based on cathodes made of lithium cobalt oxide. But the firm is “on track” to hike the density to more than 200 Wh per kg by 2017.

At that level of energy density, sodium-ion would compare very favorably to Li-ion, providing the same performance at a cost of about 30% less.

Faradion sodium ion battery energy storage

Among the advantages of sodium-ion technology cited by Faradion, the base material is abundant compared to lithium (not that lithium faces a huge supply issue).

Company sources also claim that the battery can be drained completely for safe storage and shipping.

Scott notes that Faradion comes from the Danish catalysis firm Haldor-Topsøe and global electronics leader Sharp.

Faradion has a ways to go before it can scale up beyond electric bicycles, but the company cites the following advantages to make a good case for more R&D:

Availability and Cost: Na-ion materials have lower material costs than Li-ion materials (e.g. sodium carbonate is < 10 % of the cost of the equivalent lithium salt). Furthermore, cathode and electrolyte costs can be ~ 50 % of cell costs, so the overall cost reduction is substantial.

Na is far more abundant in the earth’s crust than Li (Na ~ 2.6 % vs. Li ~ 0.005 %) making this technology more sustainable.

Drop-in solution: Na-ion materials can be processed in the same way as Li-ion materials at every step, from the synthesis of the active materials to the electrode processing…Existing Li-ion manufacturing lines can be used to make Na-ion batteries

Current collectors in sodium-ion cells can be fabricated from aluminium rather than the more expensive copper necessary in lithium cells.

Faradion also claims an energy density “similar” to that of  typical Li-ion materials, and initial tests demonstrate rate capabilities on par with Li-ion.

As for next steps, Faradion has paired up with the company Williams Advanced Engineering in an energy storage project co-funded by the agency Innovate UK, so stay tuned.

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Image credits: Top via Oxis Energy, bottom via Faradion.

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About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

  • Bristolboy

    And obviously if such battery “breakthroughs” do occur they will not only benefit EVs but also potentially support further renewable energy integration.

    • Bob_Wallace

      Maybe. But the storage market is bifurcated. EVs need light weight and compactness which is not an issue for utility/end-user storage.

      • Bristolboy

        I agree light weight does not have a material impact on end user usage, however compactness is a benefit especially in countries such as the UK where space is at a premium.

        However, the real benefit for non-EV energy storage was in relation to the cost “breakthroughs” – Oxis Energy are claiming to have batteries which on a kWh basis are about half that of Tesla. If that happens, the storage market will be in for a massive boom worldwide!

        • Bob_Wallace

          Yes, but as someone who has followed batteries/storage for a few years I’m now from Missouri. I’m not getting excited about claims, gotta show me.

          I think Tesla is months, perhaps as much as two years, from $130/kWh for cells and that price should work its way down to $100/kWh.

          If that’s as good as we get, it’s good enough.

          Any new less expensive tech, any breakthroughs will make things even better but I’d recommend keeping the Oxis type stuff in a “perhaps” bag unless they prove themselves as real.

          • Jacob

            Given the lesser cycle life of Oxis batteries, I would imagine Oxis batteries will be put in mobile phones or laptops.

            Higher energy density but less cycles than Li-ion.

            A Samsung s5 battery retails for $30. A lot of people would pay $60 for an Oxis battery if it has higher density.

            Cars would keep using Li-ion unless there is a genuine breakthrough in Al-ion.

          • Bob_Wallace

            If they can provide 2,000 cycles before dropping to 80% capacity that’s 400,000 miles in a 200 mile range EV.

          • Jacob

            What about cost per kWh.

            Tesla is far ahead in cost due to the Gigafactory.

            Oxis probably cannot set up a Gigafactory.

        • Karl the brewer

          “compactness is a benefit especially in countries such as the UK where space is at a premium”

          This +100000000

          Lots and lots of terraces / semis here in the UK with no garages or outhouse for batteries. So it’s either loft space or in kitchen maybe?

          • Bob_Wallace

            If we’re talking end-user storage.

            But, honestly, I don’t think end-user storage is going to be a big thing. I doubt the savings from purchasing from the grid will be enough to cause a lot of people to set up their own systems.

            US/Germany. The average electricity bill is around $100/month. Perhaps high volume users will find it economically worthwhile, but those folks generally have deep pockets and might not bother in order to save $50.

          • Jenny Sommer

            Not even the poorer folks bother about electricity cost in Germany. About 40% don’t bother to leave their base supplier. I just switched my utility. Save 180€/a@~3800kWh/a.

            The thing is that PV installers will sell you the batteries in the package once payback time approaches that of the rest of the system.
            My aunt installed 4KW for 6400€ last month and the installer told her that people are buying batteries already although they will never make a return on them.
            Demand doesn’t seem to be the issue.

          • I guess a small percentage will, but most of us want to see enough ROI to make the hassle and risk worth it. Since I pay the wind generation companies for my power, I don’t have a lot of incentive to install solar on my roof – even though I have a large, 2nd story area gently sloping to the west that looks perfect. I’m happy to let them front the installation cost and long-term risk, since it’s an environmental wash afaict.

          • Jenny Sommer

            The decission in PV panels is an economical. If you got some money and believe there is a better investment by all means don’t install PV.

          • In at least my part of the USA, I believe we sell excess residential solar / wind energy to the grid for wholesale – less than half of retail. Caching that in a reasonably priced battery for use on windless nights might give a payback period for the battery system of less than 30 months, which is where financially successful people tend to start paying attention.

            So that calculation would yield the price target for people interested in residential power generation.

          • Jacob

            Japan, Hong Kong, etc.

      • Matt

        Hear hear, and in fact there are really multiple opportunities in the stationary market. So we can have multiple big winners.

  • jec

    Haldor Topsøe is a Danish Company and not Dutch

  • Marion Meads

    In other words, Lithium Ion batteries leak or lose energy through time. How much charge, watt-hours, do Tesla batteries (their 85 kWh pack) lose per month from a full charge, assuming no vampiric loads, just leaving the batteries unused?

    • eveee

      Oh Marion give it up. You have lithium confused with NiMH.

      At room temperature at 60% charge, its 4% per month. Thats not including vampire loads. It goes down fast at full charge and then decreases.


      Tesla is about 1% per day.

      • Jacob

        If they put a thin film solar panel on the bonnet of Tesla cars, they could prevent that from happening.

        • eveee

          Yes. I could buy one of those cheap ones with the little fan used to cool car interiors. Would add class to my Tesla purchase. Or just get a cheap from Harbor Fright and lay it on the hood and attach clip leads to it.
          Come to think of it, I could start a biz selling those things. Just make it a DIY with sticky back tape and Velcro for mounting on the hood. Make it look like a hood ornament. Increases resale

          • Jacob

            You mean increase battery charge.

          • eveee

            My bad sense of humor. Really, it could be done. And it makes some sense. Just don’t park in an underground garage.

    • Jacob

      Because the Sadoway liquid metal batteries do not suffer that problem eh.

    • nakedChimp

      Marion, can you please show us on the doll where the Tesla touched you?
      What is you’re mild hatred towards Tesla based on please?

      • Genuine lol 😀

      • Bob_Wallace

        That’s the first time in a long time that I’ve actually laughed out loud over a comment on the internet.

      • Ghostdawg

        I just spit out my coffee..and some of it went up my nose somehow…Well Done. 😉

  • If I worked for Tesla research and was in the audience as Oxis presenting their findings at the Society of Chem E. Dorks, I’d focus on how they spelled nickel as nikel on the graph. I’d bite down hard at that bone like a rabid dog. Then suck out all the oxygen in the room with comments like, “how the hell can we trust this bogus research when you idiots can’t even spell nickel right.” Of course I don’t work at Tesla and I think this battery competition is awesome. Nevertheless, I’ve seen worse attempts at kneecapping someone else’s research at society presentations. Science ain’t beanbag.

  • wattleberry

    This update of the 14 July posting is worthy of a resumption of the responses to that, if only because of the holding of the charge and the ability to produce on the same production line as li-ion.

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