TDK Claims Solid State Battery With 100X Energy Density

Regulations surrounding disposable batteries have accelerated a quiet race to replace coin cells, which on the whole are not readily rechargeable. TDK produces solid-state batteries and has announced a new material that claims an energy density of about 100 times that of their conventional batteries.

Energy density measures how much energy a system contains relative to its volume. The new battery has 1000 Wh/L. For comparison, old nickel-cadmium cells had about 150 Wh/L. A typical lithium-ion battery usually turns in about 200 – 250 Wh/L.

There aren’t many technical details, but a few things caught our interest. For one, it uses an oxide-based solid electrolyte and lithium alloy anodes. However, what really caught our eye was that it is “intended for use in wearables… that come in direct contact with the human body.” We don’t know if that means the material is safe for your skin or if it depends on being next to your body to operate.

While the energy density is high, keep in mind that the batteries of this type are usually tiny, so the total actual power available is probably not very high. Tiny batteries are definitely a thing. We are always hearing about breakthroughs, but we always wonder if and when we’ll see actual products.

49 thoughts on “TDK Claims Solid State Battery With 100X Energy Density

  1. >A typical lithium-ion battery usually turns in about 200 – 250 Wh/L.

    Nope. About 250–693 Wh/L

    There’s two energy density metrics. By weight and by volume, and you’re mixing them up. Usually when you see publications about “breakthrough batteries” advertised for high energy density, they use the volumetric energy density because it’s easier to get big numbers on a bare cell level, sometimes literally without any sort of shell or casing around the electrodes. Achieving 1000 Wh/L like that isn’t news.

      1. Be careful using the word “any”, I’m sure it won’t take long before somebody will mention a kind of density that is not related to volume.

        For example:
        I wonder how high density floppy disks should be looked at. You can’t speak of a volume as the medium it refers to is 2 dimensional.

        Printing density is similar

        1. Gravimetric energy density is Watt-hours or Joules per kilogram. The more proper term for this is “specific energy”, but Wh/kg is commonly called “energy density” when talking about batteries, because the mass of your batteries is generally more limiting than how large they are.

          1. I was referring to the method of storage, which only happens in two planes (x and y). I was aware of the fact that disks have a thickness ever since it tried to put 150 disks into a diskbox intended for only 100.

            Thank you for the link to the informative website.

  2. I’m having issues with my calculator, as I can’t figure out the math that justifies the headline of this article that mentions “100X Energy Density”

    new battery : 1000 Wh/L
    old nickel-cadmium : 150 Wh/L
    lithium-ion battery : 200 – 250 Wh/L.

    I’m using a Casio CFX-9850GC PLUS, what could be the issue of my calculations as I can’t see any improvement factor higher then 6.66666666666666667

        1. I am sure *someone* has used that marketing trick, but no, in this case only the Hackaday headline says “100X”, everything else says “100 times”, and it really is 100 times better than *something*, just not NiCads or Lithium.
          (as [uzeki] mentions, it’s TDK’s conventional solid-state batteries, which presumably deliver around 10 Wh/L.)

          And you could argue that there are, of course, still marketing shenanigans going on – they are ignoring competitors’ batteries that are already available and delivering around 50 Wh/L.

          Of course that’s still a 20x improvement, and notable for finally surpassing more conventional battery chemistries. *if*, of course, it can actually be taken from the lab to a viable commercial product.

          1. Ah!
            Just maybe, the 100X is binary!
            That would explain why the improvement is in the single digit (decimal) range!
            Sneaky marketers!

      1. X doesn’t have a specific value.
        Neither does it have to be added.
        No operator implies it’s a multiplicative example.
        Could also be tensor.
        What type/order of fit would you like?

        Math majors could get PhDs, describing examples of finagler’s ‘constant’.
        It’s always some variant of (answer you got)/(answer you want).

        But it’s also useable by innumerate marketing types.
        They seem to have an instinct about this type of math.

  3. -That’s the miraculus battery of the week! Wait for the next week one,! It will be 1000 times better!
    -Ok, but when will be able to buy the ba-
    -No, wait you didn’t answ-

  4. > However, what really caught our eye was that it is “intended for use in wearables… that come in direct contact with the human body.” We don’t know if that means the material is safe for your skin

    The insides of the battery should not ever contact the user’s skin. Anything with enough reactivity to yield that kind of energy in a battery is not going to be pleasant to touch.

    > or if it depends on being next to your body to operate.

    It’s a battery, not a crysknife, bud. Reality does not work that way. They mean that they expect it to be stable enough to not leak or set itself on fire like comparably energy-dense wet electrolyte lithium batteries.

  5. funny. i just read a warning about this TDK news on another site. Many news site have published this news with just the claim of a new battery with 100x the energy density. no one botherd to question what they actually published or check the source. They all fail to mention that this is just compared to TDKs older generation of batteries. There are other manufactureres that have apparently even higher values already in production. TDK was way behind and has now just updated their products to the current state of the art.

      1. Except it’s not 100 times the energy density of their conventional batteries. It’s 100 times the energy density of their previous *solid electrolyte* batteries, which came in at 10 Wh/l because they were a first attempt at commercializing an immature technology. And which hardly anybody bought because they were freakin’ useless for most applications while being expensive as hell.

        But the impression they wanted to create was that this new thing was being compared against the batteries you’re familiar with. That would be a complete lie. They didn’t technically tell that lie because they included qualifiers whose significance isn’t obvious to the layman. By retelling the story without the qualifiers, you’ve constructed the lie they wanted to tell but couldn’t and then spread it far and wide.

        I get that Hackaday isn’t an institution of Serious Journalism, but it is a place where I expect a modicum of critical thinking, or at least something better than credulous parroting — and exaggeration — of the distorted weasel words of a bullshit press release. That’s not just because I think it should be that way; that’s the bar that has been set by your colleagues’ work.

        1. You expect critical thinking from Hackaday editors?

          No _must_ be new here.

          When the check clears or unspoken act (involving 555) is complete, the youtube vid/press release is linked.

  6. I’ve read so many articles about battery breakthroughs in the last 10 years, that I’ll believe it when I can buy it in the store. Mercedes said in 2022 that they will release EV’s with solid state batteries in 2023. It seems to be mostly marketing.

    1. yeah i’ve watched the same process especially with data storage as well. there are always labs producing prototypes that look like they’re a 10x improvement in one generation, making headlines…and then disappearing as they feel the weight of actually trying to turn anything into a product, dealing with realities of cost and scalability and repeatability and so on.

      but the flipside is even though the late 1990s headline of holographic storage providing 1TB/cm^3 overnight never came through, i *do* have multiple TBs in astonishingly small packages. and the same is happening with batteries — we aren’t seeing big 10x improvements but there is constant incremental improvement. so i’m still pleased :)

  7. I tried converting this to the battery size of the Apple Watch Series 6.

    Estimate for that watch was 653 Wh/L.

    Estimated out to 28 hours, from Apples estimate of 18.

  8. I’ve read about this in other places and they’re saying there’s a ceramic material that’s relatively brittle, which is why they’re targeting small devices like smart watches. Larger devices – even phones – have “unfavorable mechanical properties” that prevent scaling beyond a headphone or smart watch battery for now.

  9. Found on Hackernews, posted here, should be at the top of every battery tech article:

    Dear battery technology claimant,
    Thank you for your submission of proposed new revolutionary battery technology. Your new technology claims to be superior to existing lithium-ion technology and is just around the corner from taking over the world. Unfortunately your technology will likely fail, because:

    ☐ it is impractical to manufacture at scale.
    ☐ it will be too expensive for users.
    ☐ it suffers from too few recharge cycles.
    ☐ it is incapable of delivering current at sufficient levels.
    ☐ it lacks thermal stability at low or high temperatures.
    ☐ it lacks the energy density to make it sufficiently portable.
    ☐ it has too short of a lifetime.
    ☐ its charge rate is too slow.
    ☐ its materials are too toxic.
    ☐ it is too likely to catch fire or explode.
    ☐ it is too minimal of a step forward for anybody to care.
    ☐ this was already done 20 years ago and didn’t work then.
    ☐ by this time it ships li-ion advances will match it.
    ☐ your claims are lies.

    People posting these articles could at least take a moment to clarify what’s being claimed – discovery of a new material is not the same as “we have an actual battery you can buy right now that meets these claims”.

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