Did U Of M Come Up With Solid-State Battery Breakthrough?

AUG 17 2018 BY MARK KANE 80

Nathan Taylor, a post-doctoral fellow in mechanical engineering, inspects a piece of lithium metal in the Phoenix Memorial Laboratory building. Image credit: Evan Dougherty, Michigan Engineering

Solid-state batteries one step closer

The research team at the University of Michigan announced a breakthrough development in solid-state batteries that in the future could double the performance of conventional lithium-ion cells.

The new chemistry uses a solid-state electrolyte and metallic Li anode. According to tests, charging capabilities increased from the typical 20-50 hours for a full charge (which is too long) to just three hours or less, without cell deterioration seen after 22 days of cycling.

Lithium-metal batteries (known for some 40 years) are not easy to tame, because it could combust when charging. The University of Michigan created a ceramic layer of garnet Li7La3Zr2O12 (LLZO) so the surface of the anode is stabilized against cycling, and the ceramic has the function of the solid-state electrolyte too. It’s still in early stage of developments but who knows, maybe this new formula will turn out to be successful.

The University of Michigan’s article explains the difference between conventional lithium-ion batteries and those with lithium anode and solid-state electrolyte:

“This could be a game-changer—a paradigm shift in how a battery operates,” said Jeff Sakamoto, a U-M associate professor of mechanical engineering who leads the work.

In the 1980s, rechargeable lithium metal batteries that used liquid electrolytes were considered the next big thing, penetrating the market in early portable phones. But their propensity to combust when charged led engineers in different directions. The lithium atoms that shuttle between the electrodes tended to build tree-like filaments called dendrites on the electrode surfaces, eventually shorting the battery and igniting the flammable electrolyte.

The lithium ion battery—a more stable, but less energy-dense technology—was introduced in 1991 and quickly became the new standard. These batteries replaced lithium metal with graphite anodes, which absorb the lithium and prevent dendrites from forming, but also come with performance costs:

  • Graphite can hold only one lithium ion for every six carbon atoms, giving it a specific capacity of approximately 350 milliampere hours per gram (mAh/g.) The lithium metal in a solid state battery has a specific capacity of 3,800 mAh/g.
    Current lithium ion batteries max out with a total energy density around 600 watt-hours per liter (Wh/L) at the cell level. In principal, solid-state batteries can reach 1,200 Wh/L.
  • To solve lithium metal’s combustion problem, U-M engineers created a ceramic layer that stabilizes the surface—keeping dendrites from forming and preventing fires. It allows batteries to harness the benefits of lithium metal—energy density and high-conductivity—without the dangers of fires or degradation over time.

“What we’ve come up with is a different approach—physically stabilizing the lithium metal surface with a ceramic,” Sakamoto said. “It’s not combustible. We make it at over 1,800 degrees Fahrenheit in air. And there’s no liquid, which is what typically fuels the battery fires you see.

“You get rid of that fuel, you get rid of the combustion.”

In earlier solid state electrolyte tests, lithium metal grew through the ceramic electrolyte at low charging rates, causing a short circuit, much like that in liquid cells. U-M researchers solved this problem with chemical and mechanical treatments that provide a pristine surface for lithium to plate evenly, effectively suppressing the formation of dendrites or filaments. Not only does this improve safety, it enables a dramatic improvement in charging rates, Sakamoto said.

“Up until now, the rates at which you could plate lithium would mean you’d have to charge a lithium metal car battery over 20 to 50 hours (for full power),” Sakamoto said. “With this breakthrough, we demonstrated we can charge the battery in 3 hours or less.

“We’re talking a factor of 10 increase in charging speed compared to previous reports for solid state lithium metal batteries. We’re now on par with lithium ion cells in terms of charging rates, but with additional benefits. ”

That charge/recharge process is what inevitably leads to the eventual death of a lithium ion battery. Repeatedly exchanging ions between the cathode and anode produces visible degradation right out of the box.

In testing the ceramic electrolyte, however, no visible degradation is observed after long term cycling, said Nathan Taylor, a U-M post-doctoral fellow in mechanical engineering.

“We did the same test for 22 days,” he said. “The battery was just the same at the start as it was at the end. We didn’t see any degradation. We aren’t aware of any other bulk solid state electrolyte performing this well for this long.”

Bulk solid state electrolytes enable cells that are a drop-in replacement for current lithium ion batteries and could leverage existing battery manufacturing technology. With the material performance verified, the research group has begun producing thin solid electrolyte layers required to meet solid state capacity targets.

The group’s findings are published in the Aug. 31 issue of the Journal of Power Sources.

The research is funded by the Advanced Research Project Agency-Energy and the Department of Energy.

Article: Demonstration of high current densities and extended cycling in the garnet Li7La3Zr2O12 solid electrolyte

Source: University of Michigan, Green Car Congress

Categories: Battery Tech


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80 Comments on "Did U Of M Come Up With Solid-State Battery Breakthrough?"

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It’s like there’s a “potential battery breakthrough” clock set for every 6-8 weeks..

More like every week. They don’t all get reported here at InsideEVs.

There’s lots of challenges to be solved. And a lot of what gets reported as a “battery breakthrough” is a breakthrough in the sense that we learned something new and gained insight into a process we already knew is relevant to the characteristics we are interested in changing (e.g. dendrite formation, which does happen in li-ion cells too, contrary to the impression the article gives). Gaining new insight IS of course something that POTENTIALLY will lead to a new, useable technology, but it isn’t the same. So it’s perfectly normal for there to be a huge number of potential breakthroughs in this sense than there are new technologies emerging on the market. In other words, much comes down to what you read into such statements. If you fall for the temptation to think “this means there will be revolutionary new batteries on the market real soon” you’re obviously going to be disappointed most of the time. But if you think hundreds upon hundreds of discoveries and almost as many teams working to figure out how to put them to use isn’t going to eventually lead to anything new, I think you’re betting too cynical. Not sure what you meant. You… Read more »

Well said, Terawatt.

That’s a well thought out, fair statement. You articulate well, and cause me to see your point from another angle. Thanks for that. At the end of the day, you’re right- everyone is searching valiantly for a huge breakthrough, and we need that, I hope it doesn’t stop.

You’ve heard the last negative comment from me regarding battery advancement, thanks!

I very much agree with the sentiment in general; and it is very well phrased!

I’m not so sure about the merits of the specific paper discussed here, though. To answer the question posited in the title: we actually do not know whether they came up with any sort of breakthrough at all. The abstract seems rather sketchy, sounding more like an advertisement. While it boasts some numbers that are supposed to be a breakthrough (but do not actually look all that great), it doesn’t really mention what they did to achieve the supposed breakthrough.

Who knows, maybe the actual research is solid — but the abstract at least is definitely substandard.

You can use graphite anodes with solid electrolyte/separator, that would be safer.

File a patent?

You must have the money to defend a patent or it is worthless.

Certainly not true. Just because there are occasionally patent disputes doesn’t mean they are generally worthless.

Patent are worse then worthless, outright noxious, if you look at the bigger picture.

If a large corporation steals and you don’t have millions for lawyers, they win.

Yes patents are an instrument for corporations to rule over individuals. God forbid they pay anything to an individual inventor.

Also no performance gain whatsoever

Not true. Even if you have the same energy density and power density at the cell level, better thermal stability translates into more energy dense, faster-charging, or both, battery packs. You can reduce cooling and thus pack cells more tightly taking out all or just part of the advantage in energy density, and the rest in faster charging. Making the pack smaller with less cooling reduces size (tautology!), weight, and cost.

It’d be evolutionary rather than revolutionary, but it sure isn’t without benefits.

“better thermal stability translates into more energy dense”
To some degree, perhaps. But they still need to be cooled so not by much.

Energy density is by far the most important factor. So no-one would take a dump on it with the graphite anode. A costly change without a gain in energy density is just not worth it.

Well, you could still have gains at the cathode side… Though the paper discussed here doesn’t look at that at all; so it’s kinda off-topic.

One of the main goals is to get rid of the useless weight of the graphite electrode…

Where did you get your electro chemistry degree?

You don’t need a degree to see this. (It has nothing to do with electrochemistry actually…) The main objective is to increase energy density. The very reason they’re pushing with solid state is because it allows to dump graphite from the anode.

Must charge/run at 60°C (140°F), This is a deal breaker as energy must be expended to keep it this hot.

22 days at 6hr/cycle = 88 cycles. Must be tested to thousands of cycles to claim improvement over other designs. Have to improve cycling time further.

60°C (140°F) is less than some household hot water temperature. It will not be that much to heat up the battery if fast charging is needed. Slower charging could be done at room temperature.

60°C – that’s not very high. I believe that’s an average body temperature of an upset Tesla troll or an excited Elon fanboy.

Don’t excite Elon this week – Automotive News revealed he was crying to the NY Times this week over it being ‘the most stressful year of my career.’ Probably Board Member rumblings over legal action are at least causing a few of the tears.

He excused his tweets lately since he is working, so he says, 120 hours per week. I thought only lawyers charged that many billable hours to a case per week, saying they couldn’t sleep since they were thinking about the case.
He says he can’t sleep without Ambien.

I would have thought all his Mansions would give him a bit of perspective to salve himself.

60°C household hot water? That would be a seriously dangerous household to live in…

“As a standard, the maximum temperature of water delivered to the tap by residential water heaters is 120 degree Fahrenheit (48 degree Celsius). […] 140°F (60°C) lead to second degree burn in 3 seconds and third degree burn in 5 seconds.”

This is BS. You can drink 50°C water (I measured it), it’s unpleasant, but not too hot.

Fast food coffee is 70-80°C and yes it can cause serious burns in seconds.

What’s more, even at this temperature, they only charged at 1/3 C to get these 88 cycles — that’s on par with old-school laptop and mobile phone batteries, but way too slow for EV fast charging.

There’s been alot of progress in solid state technology of late. I think the most promising and impressive is the Ionic Materials battery. Only a matter of time one of these darts will hit the bull’s eye.

When the “hit the bull’s eye” moment is finally reached, at the research stage, it may take more than a few years to ramp up production.

The new LLZO solid state electrolyte lithium ion batteries, if proven viable for EV use, given competitve cost and performance metrics, are probably going to reach significant industrial production numbers.

Whom amongst the current crop of existing legacy ICE OEM auto makers, will make the first, next generation SS Li-Ion battery, move?

I think it’s more likely that SS batteries will first be seen in an EV that’s not made by a legacy auto maker. Startups are more likely to do something risky like put batteries into a production car before they’ve been subjected to very thorough testing over a period of time.

Tesla has transitioned out of the startup phase, but there are others, such as Rivian, Karma, and Nio, which might be willing to bet on a new tech before it has been thoroughly tested.

Lots of major manufacturers are investing in solid-state. Whether they are betting on it or hedging their bet on li-ion as we know it is debatable, I guess. But if the batteries are inherently very safe it’s probably riskier not to introduce them than to do so!

I agree. Current investments in li-ion tech will probably have several years to make back three investment before any solid-state products hit the market, never mind anything we might call mature solid-state. It will take years to optimize the solid-state tech (production methods and all) and to ramp it up.

If some radically better tech emerges suddenly it still is unlikely to ramp up so fast as to make current tech worthless overnight. Even if they are cheap to produce, much better batteries would then be expensive because of supply constraints for a few years.

In short there’s both technical and economic reason to think solid-state won’t make a huge impact on the road in years. But I do believe it is coming, and once it does any further investment in li-ion as we know it would seem rather risky.

“Even if they are cheap to produce, much better batteries would then be expensive because of supply constraints for a few years.”

Exactly. Why would a startup battery maker with a revolutionary battery sell its new “super battery” to EV makers at, say, $150/kWh when it can sell them to cell phone makers for a much, much higher profit margin?

Mr. Google says an iPhone battery contains 5.45 watt hours. So let’s say the super battery maker offers Apple a 20 Wh battery for $100, and for makers of cheaper cell phones, offers a 10 Wh battery for $60. That would be a market which a startup would spend several years ramping up to supply. More likely, they’d just license their tech to existing battery makers on a royalty basis, and become billionaires overnight. It would be some years before prices would creep down far enough for the super batteries to start appearing in production EVs.

We have no way of knowing who actually has the most promising tech.

In fact, I think it more likely than not that the established battery makers actually have the best tech: they just don’t feel the need to boast about future products that are still uncertain and years away from hitting the market — unlike the start-ups trying to secure funding based on such vague promises…

Solid State will be here in 3-5 years. Mass production capabilities, that may take a few more.

If you ignore the lack of mass production capabilities, solid state batteries are already here.

Yup. Ionic Materials did a lab demo of its solid state polymer “plastic battery” for PBS’s “Nova” documentary series a year or two ago. That looks very real, altho some questions (such as longevity) remain.

But so far as I know, no solid state batteries are yet in commercial production.

There is at least one start-up claiming to be commercially supplying solid-state batteries to aerial drone makers… Without naming the customers, though.

Samsung Galaxy 9 has solid state.

Source? I don’t see anything supporting this.

I wish more people understood the immense set of challenges between, “Hey! Look what I made work in the lab!” and “You cna go to your local car dealer/store/web site and buy a product that uses this new thing”. Anything in a car is particularly difficult, given usage patterns, environmental conditions, crash testing, TCO, etc.

Still, I’m confident that with all the corporations and universities chasing the BBB (big batt. breakthrough) that someone will find it. It might be a tweak to lithium chemistry or an ultracap or a liquid battery or some crazy thing none of us it talking about. The potential economic gain from making that BBB, plus the attendant fame, are so high that I can’t believe it’s physically possible yet won’t ever be found.

Yeah, I like to use a baseball analogy. There are a few players, such as Ionic Materials, who appear to have gotten safely to first base, and Ionic may be getting close to second. But far too many of them, such as the one described in this article, are just taking practice swings before the pitch.

Not a single one of these solid state battery development projects appears to be even remotely close to a home run. Furthermore, it’s almost certain that the first mass production use of SS batteries will be for cell phones or laptop computers. It will take a few years after that, or several, before costs come down far enough to start using them in mass production EVs.

In this case, they didn’t even make a working cell in the lab. Going by the abstract, they just tested the anode/electrolyte interaction in a dummy cell that doesn’t actually store energy.

Which is not to say it’s a bad thing. This kind of research is necessary for advancing battery technology. As you say, it’s just important to understand that it’s not something directly resulting in an actual product.

I don’t put much hope in a “big breakthrough”, though. Given the amount of battery research we see today, it just doesn’t seem very likely there is still some game-changing breakthrough waiting to be discovered. Anything actually making it market is more likely to come from painstaking gradual improvements to known technologies.

“charging capabilities increased from the typical 20-50 hours for a full charge”

I’m sorry, what?

A lot of these next-gen cells have slow charge/discharge rates and low cycle lives. They’ll improve somewhat by the time the new Roadster ships, but that’s one reason it has 200 kWh.

Solid state batteries once perfected mean the swift death of the infernally combusted engine. This makes the innovation here being discovered in a lab AT THE UNIVERSITY OF FREAKIN’ MICHIGAN very ironic, indeed.

I bet a whole new industry will develop to replace old battery packs with new solid state packs.
Looking forward to having 1,500 mile range in my TM3 by 2050.

EEStor is really close based on their latest published reports on their website. Ian Clifford will shortly be replacing Elon Musk as the EV genius!

Musk forever, Clifford never!

lol, eestore such a scam

Even their imaginary technology is inferior in energy density to Li-ion batteries.
Supercapacitors wold be fine as buffers for high power re-gen or something, but their claims were perpetually proven to be empty.

The Saudis wanting to buy Tesla and the University of Michigan, deep in the capital of gascardom finding breakthroughs that would end the reign of gas cars….Is the world on a CRAZY TRAIN lately, OR WHAT?!!😀

Or is this manifest destiny?

(Drops mic and walks away)

Saudis are looking to diversify:


The article says that this was published August 31. Is that wrong, and if not, what year?

It’s only fair, this Solid State technology is the stuff of the future!

Research indicates that the future of research, and those that report on it, looks likely.


The August 31 issue of the Journal of Power Source is just the way they say the August 2018 issue. This is where U of M submitted their research to be published.

Could be worse. In the days when news stands were everywhere, some publishers dated their magazines a month or even more in advance, in the hope that they would stay on the stand longer. Comic books were dated 3 months in advance!

“It’s still in early stage of developments but who knows, maybe this new formula will turn out to be successful.”
This sentence summarizes all “battery breakthrough”, before writing bombastic article, should ask, “How scalable is it?”

Hehe, ok – what is going on here is a bit of a scam apparently – I’m not talking about the individual merits of this particular case – I’m talking about all these “HUGE BREAKTHROUGHS” in general.

Its rather like, in 1951 Venezuela claimed a HUGE BREAKTHROUGH in Nuclear FUSION POWER. Problem was no one could duplicate it.

Lately, there are, from time to time – announcements of huge breakthroughs in FP, (usually when the gov’t funding is about to expire and many ‘Scientists’ would be put out of a job) – the reason for the quotes is they are obviously being NAUGHTY – they know they are plowing down a dead end street, but its not revealed to be generally the case to outsiders until much later.

So – I’ve seen this movie before. The researchers in general are not revealing ALL they know….. They won’t tell you they’re on a dead end street until they are forced to.

How many academic researchers do you actually know..?

IDK what it’s like in the US, but in Norway researchers usually work as professors at a University and don’t make a dime more when in a research project than when not in one. The only way they can profit from the research is if it is patented and commercialized. Hence they have every incentive to get off what is a known path to a dead end ASAP, and pursue another path instead.

Ho hum, another wide-eyed, breathless announcement of a battery tech breakthrough, with no analysis of the ability to mass produce the product, or any indication of the cost.

Must be a Friday. 😉

Clever! Sounds very promising.

Reading all the negative comments, it astounds me how few people can interpret this news for what it’s worth. Everytime they see the ‘breakthtough’ word, they go all bezerk, expecting a 10 kWh/kg battery with 5 s fast charge capability for a dollar per kWh available at your local store today.

Grow up folks, technology advances one small breakthrough at a time. Today’s batteries contain yesterday’s breakthroughs.

Cool… maybe… but hmm coming from Motown… and a “hey wait” attitude… this sure smells like FUD. More fear, uncertainty , and doubt sowing by the companies that don’t want EVs to happen for some time yet.

Somebody else think that this dispersion in the searching of new technologies is retarding the progress of the EV’s?. If more people focus on one technology, they could progress faster. But it looks like every university, every country, every company wants to discover its own philosofal stone and this divide the resources.

The shotgun approach vs. the hunting rifle. There is a good point there.

They’d call that vile, evil communism.
We have capitalism, so wasting the wast majority of research, resources is awesome, because it’s “competition”.

The problem is that the one tech which should be focused on is only apparent in hindsight. There isn’t any crystal ball which will tell researchers and startups which is the one tech they should be pursuing.

A relevant quote:

Thomas Edison, when queried by a reporter about the seemingly incredible difficulties associated with his work on the lightbulb rebutted, “I have not failed 700 times. I’ve succeeded in proving 700 ways how not to build a lightbulb.”

Competition may be inefficient, but ultimately results in better products. The alternative is the old Soviet-style market, without competition, where there is only a single product, and usually a mediocre one at best.

“Competition may be inefficient, but ultimately results in better products. The alternative is the old Soviet-style market, without competition, where there is only a single product, and usually a mediocre one at best.”

Dead wrong. What it accomplishes is waste. Collaboration and result sharing is what would be productive.

The soviet-style market is not the alternative, it’s one of many alternatives.

“Collaboration and result sharing” is exactly what academic research is all about…

The point here was that researchers supposedly should all focus on a single technology — which is frankly nonsense.

(Though bringing up Soviets is indeed totally beside the point.)

I’ve been saying for a long time I think solid-state is coming, and will supplant the current battery tech when it does.

The high energy density is a main reason, but the high conductivity (low internal resistance) and much improved thermal stability is just as important. Halving the resistance means doubling the power for a given amount of heat produced. And here we’re more likely looking at a tenfold improvement. That means much faster charging is possible at little or no cost (and more power when driving is possible at the cost of the power electronics). Combined with a much wider operational thermal window this means that battery packs can use less cooling, which further improves density at the pack level. I therefore think a mere doubling of energy density compared to NMC811 is too conservative.

Solid-state cells should also eventually be easier to produce fast. The liquid electrolyte is a major reason why it’s difficult to speed up cell production, at least for pouch and prismatic cells.

I think the same. But I’m not really that hopeful anymore about seeing it soon.

“energy density compared to NMC811 is too conservative. ”

Actually moving to a solid electrolyte doesn’t inherently touch the cathode side (as far as I know) so the battery still might be NMC811, unlike the anode side because one of the main goals is to move to pure lithium.
However you can hear about researches for better cathodes too. Most promising seem to be selenium or sulfur based cathodes. But I get the sense that these are a lot further from marketable state.

Thanks, I should have been more clear. The solid state electrolyte enables more energy dense electrodes because of its much higher chemical stability and inflammability.

” The solid state electrolyte enables more energy dense electrodes because of its much higher chemical stability and inflammability.”

There’s no relevance between the energy density of the electrodes and the choice of electrolyte. They’re completely separate components. Solid electrolytes might be lighter, but I never heard mention of this.

Actually, the whole point of solid state electrolytes is being able to use denser electrodes that would be too reactive to work with current electrolytes. (Lithium metal anodes being the major focus most of the time — including the paper discussed here.)

It should be noted though that there is in fact also quite promising research on improved liquid electrolytes — so it’s not all that clear that solid state is indeed the future…

I know. He just claimed that inflammability and “higher chemical stability” of a solid electrolyte somehow enables more energy dense anodes. In actuality it’s ability to prevent dendrites which do, for the anode side, it does nothing to the cathode side.

I’m not sure about lithium mental anodes: but for carbon or silicon anodes, electrolyte reactivity *is* a serious problem; and it’s even more of a problem on the cathode side. It’s the main reason for battery degradation, especially at elevated voltages (thus limiting usable capacity); and it’s one of the major challenges to improved chemistries — including higher nickel contents, as well as some other candidates.

Solid state electrolytes do not have high conductivity. On the contrary, low conductivity is one of the major challenges that have to be overcome. (That’s why it’s often mentioned in research papers.) While solid state electrolytes are seen as one promising potential path to end parasitic reactions at both electrodes, they also come with major challenges. Thus there is also a lot of research on other approaches, such as electrolyte/electrode combinations naturally forming stable interface layers, and/or pre-fabricated coatings/membranes providing such layers. As for density improvement potential, it depends on what we are looking at. Merely replacing the anode with a lithium metal one won’t double gravimetric density — not even when considering potentially reduced cooling requirements I believe. (Doubling volumetric density might be possible I guess.) Along with a different cathode, we might indeed see more than doubled density; but that seems further out, with additional breakthroughs required. AFAIK the major time (and energy) sink in cell production is the need to dry the electrode materials after coating as a wet slurry. That happens before adding any electrolyte. (Improved electrolytes *might* save time elsewhere, by reducing the need for conditioning the cells after assembly I guess — but that… Read more »