Posted on 03/08/2022 12:50:55 PM PST by Red Badger
A method for stabilizing the interfaces in solid-state lithium-ion batteries opens new possibilities.
In the endless quest to pack more energy into batteries without increasing their weight or volume, one especially promising technology is the solid-state battery. In these batteries, the usual liquid electrolyte that carries charges back and forth between the electrodes is replaced with a solid electrolyte layer. Such batteries could potentially not only deliver twice as much energy for their size, they also could virtually eliminate the fire hazard associated with today’s lithium-ion batteries.
But one thing has held back solid-state batteries: Instabilities at the boundary between the solid electrolyte layer and the two electrodes on either side can dramatically shorten the lifetime of such batteries. Some studies have used special coatings to improve the bonding between the layers, but this adds the expense of extra coating steps in the fabrication process. Now, a team of researchers at MIT and Brookhaven National Laboratory have come up with a way of achieving results that equal or surpass the durability of the coated surfaces, but with no need for any coatings.
Discs for Testing Solid-Electrolyte Batteries These discs were used for testing the researchers’ processing method for solid-electrolyte batteries. On the left, a sample of the solid electrolyte itself, a material known as LLPO. At center, the same material coated with the cathode material used in their tests. At right, the LLPO material with a coating of gold, used to facilitate measuring its electrical properties. Credit: Pjotrs Žguns
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The new method simply requires eliminating any carbon dioxide present during a critical manufacturing step, called sintering, where the battery materials are heated to create bonding between the cathode and electrolyte layers, which are made of ceramic compounds. Even though the amount of carbon dioxide present is vanishingly small in air, measured in parts per million, its effects turn out to be dramatic and detrimental. Carrying out the sintering step in pure oxygen creates bonds that match the performance of the best coated surfaces, without that extra cost of the coating, the researchers say.
The findings are reported in the journal Advanced Energy Materials, in a paper by MIT doctoral student Younggyu Kim, professor of nuclear science and engineering and of materials science and engineering Bilge Yildiz, and Iradikanari Waluyo and Adrian Hunt at Brookhaven National Laboratory.
“Solid-state batteries have been desirable for different reasons for a long time,” Yildiz says. “The key motivating points for solid batteries are they are safer and have higher energy density,” but they have been held back from large scale commercialization by two factors, she says: the lower conductivity of the solid electrolyte, and the interface instability issues.
The conductivity issue has been effectively tackled, and reasonably high-conductivity materials have already been demonstrated, according to Yildiz. But overcoming the instabilities that arise at the interface has been far more challenging. These instabilities can occur during both the manufacturing and the electrochemical operation of such batteries, but for now the researchers have focused on the manufacturing, and specifically the sintering process.
Sintering is needed because if the ceramic layers are simply pressed onto each other, the contact between them is far from ideal, there are far too many gaps, and the electrical resistance across the interface is high. Sintering, which is usually done at temperatures of 1,000 degrees Celsius or above for ceramic materials, causes atoms from each material to migrate into the other to form bonds. The team’s experiments showed that at temperatures anywhere above a few hundred degrees, detrimental reactions take place that increase the resistance at the interface — but only if carbon dioxide is present, even in tiny amounts. They demonstrated that avoiding carbon dioxide, and in particular maintaining a pure oxygen atmosphere during sintering, could create very good bonding at temperatures up to 700 degrees, with none of the detrimental compounds formed.
The performance of the cathode-electrolyte interface made using this method, Yildiz says, was “comparable to the best interface resistances we have seen in the literature,” but those were all achieved using the extra step of applying coatings. “We are finding that you can avoid that additional fabrication step, which is typically expensive.”
The potential gains in energy density that solid-state batteries provide comes from the fact that they enable the use of pure lithium metal as one of the electrodes, which is much lighter than the currently used electrodes made of lithium-infused graphite.
The team is now studying the next part of the performance of such batteries, which is how these bonds hold up over the long run during battery cycling. Meanwhile, the new findings could potentially be applied rapidly to battery production, she says. “What we are proposing is a relatively simple process in the fabrication of the cells. It doesn’t add much energy penalty to the fabrication. So, we believe that it can be adopted relatively easily into the fabrication process,” and the added costs, they have calculated, should be negligible.
Large companies such as Toyota are already at work commercializing early versions of solid-state lithium-ion batteries, and these new findings could quickly help such companies improve the economics and durability of the technology.
Reference: “Avoiding CO2 Improves Thermal Stability at the Interface of Li7La3Zr2O12 Electrolyte with Layered Oxide Cathodes” by Younggyu Kim, Iradwikanari Waluyo, Adrian Hunt and Bilge Yildiz, 17 February 2022, Advanced Energy Materials. DOI: 10.1002/aenm.202102741
The research was supported by the U.S. Army Research Office through MIT’s Institute for Soldier Nanotechnologies. The team used facilities supported by the National Science Foundation and facilities at Brookhaven National Laboratory supported by the Department of Energy.
Electric is cleaner (no oil changes, dripping fluids, etc), quieter, less maintenance, more reliable...
It's the energy storage and the power density of fossil fuels vs. batteries that are the real obstacle. Fossil fuels simply pack an incredible punch by volume and weight and even though the combustion motor may only run at 30% efficiency, it is still better than an electric system where the motor runs at >90% efficiency.
If we get the weight and volume of batteries down, electric will dominate, EVERYWHERE it can practically be applied.
If we were smart and combine that with nuclear power, then it would really be greener and more energy independent. Push everything electric where it can be electric, and if the source is nuclear you are not just shifting the pollution from one place to another, but actually really seeing a reduction (CO2, H2SO4, HNO3, benzine, toluene, xylene, soot...).
Put a tad of tritium in there to up it a whole lot more.
From the title, we’re talking about vibrators, right?
Dilithium crystals, fershure.
Is Lucas Electric involved in this? I understand they were developing an alternating current battery.
I know for a fact that Lucas did make those, I had one in my Jaguar
Gonna need a higher temp and a lot of compression to get thatto work.
Consdiering a gallon of gas has 1000 times the energy capacity 2x just isn’t very much.
Fusion reactors the size of bricks.
Darn you beat me to it!
Rule of thumb the more energy you pack into chemical bonds the more unstable it likely is !
Thats Chmeistry & Physics no way around it.
“ When they develop a Battery Charger that can charge an Electric Car Battery to Last 2000 Miles and can be re-charged in an hour, that will spark electric car sales. Until then, we will stick to Gas.”
2000 miles per fill-up! What are you driving?
How do you make the ‘cleaner, quieter, less maintenance, more reliable’ electric? Asking for a friend. Guess that doesn’t matter as long as the “pollution/exhaust” happens at a power plant miles away, instead of at the back of the vehicle. Easier to feel good about oneself, I guess.
If it’s all that and a bag of chips, why isn’t every EV owner required to use solar, wind or hydroelectric to charge the batteries? The government is going to force the taxpayers to pay for charging stations all over the country. It’s handing out tax breaks, to the tune of $7500 each, for an EV. It can force people to buy health insurance.
And for some reason, I can’t seem to wrap my head around an EV being more reliable than a gas/diesel vehicle.
It sure would be nice if FR had an EV-Only page/section, so all the EV folks can comment to each other how wonderful EVs are.
Lot's of resources out there. They all belong to us. We just need to go get them.
If the US had stayed on the same path and pace it was on in the 1950s - 1970s, before it became introverted, feelings based, and real science died, can you imagine where we would be today?
There was a time where this nation was “full speed ahead” in science, and I'm not talking about BS vaccines (a cash cow for big pharma), global warming, or ozone hole nonsense (enviro scams). There was a time where the US wanted to explore the universe (Voyager), go into the depths of the ocean (Trieste), go faster and higher (X-15, space program) or know what the building blocks of life is (DNA - Double Helix discovery), we built nuclear power plants and had a Boeing 747 in 1970. By 1973 we built the Saturn V, the most complex mechanical machine ever built, and we did it with frigging slide rules! We were building ever taller buildings, longer tunnels, bigger dams...
Today, we don't even care anymore.
Today we have become all about feelings, and the means are more important than the ends.
Do you think there is a reason why we have not definitely won a war since WWII (other than Iraq in 1991 and micro military campaigns)?
Our weakness today is of the heart. We once were meat eaters. Now we're a bunch of vegan hippy homo's sitting around and talking about our feelings.
Do you think there is a reason why we were 35% of the global GDP in 1950, but ~20% today?
Do you think there is a reason why China uses more concrete than we do?
Why the tallest building is standing in Dubai?
Why US Astronauts use a Russian rocket to get to space?
Why China today has 1.5 times the patents in engineering we have?
Coming up with ever greater alliances, forums, summits and supra national institutions won't do it. That's what the Euro's did. As they decline and become ever less significant on the world stage, they think by banding together they can still have a say, some influence and weight. They don't. Look at Ukraine and how impotent they were. Israel is small but for it's small size, population, GDP, and resources extremely powerful. Why?
We in the US have a weakness that is growing inside us, like a cancer.
“It sure would be nice if FR had an EV-Only page/section, so all the EV folks can comment to each other how wonderful EVs are.”
You may go here:
https://www.reddit.com/r/electriccars/
“This r/ is especially made for every electric car enthusiast out there. “
Or here:
https://www.reddit.com/r/electricvehicles/
“...for EV owners and enthusiasts.”
Read the rest of my post: I mention that the cleaner environmental aspect would be true if we were nuclear powered. Electric is more reliable, cleaner, quieter... and if we were to get our power from nuclear, then it would even be more environmental because nuclear is very clean (no soot, CO2, H2SO4, HNO3, xylene, toluene, benzene... no coal mining...). As to the trash and resources needed for a nuclear plant (Uranium and waste). It's negligible. It's so small in volume compared to what coal and fossil fuels need that it's literally not even worth mentioning.
Not for me. I am definitely not an EV-Nerd.
Folks can talk all they want about how wonderful they are. Good on them.
Musk is reverting back to old technology because of the financial costs and environmental damage the mining causes.
Now the world is going to have Ford, GM, Dodge(eventually) building EV pickups. Toss in Tesla, Toyota, Nissan, Honda, Kia, Mercedes, BMW, Audi, Volkswagen. 12 of the biggest car manufacturers on the planet and sh*tty start-ups like Rivian think they’ll be able to compete in the market with stuff 2x as expensive.
Now, I could be 100% wrong and my memory may be a little off given how long ago it was….
Students at Cal-Berkeley were working on being able to take radioactive waste, getting the last bits of energy potential out of it, thus, eliminating the need for any of that stuff to have to go to Yucca Mtn for 200 years.
Again, I could be wrong but, I’m pretty sure I read that.
They all belong to us except Europa
What fun is that?
Yup. There’s a LOT more oil in the world then there is lithium.
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