24M Introduces Semi-Solid Lithium-Ion Battery Cell

JUL 6 2015 BY MARK KANE 46

24M: A More Efficient Cell Design. Materials design enables up to 5x the area capacity of standard Li-ion.

24M: A More Efficient Cell Design. Materials design enables up to 5x the area capacity of standard Li-ion.

A 24M technician holds one of the company's new semisolid lithium-ion battery cells

A 24M technician holds one of the company’s new semisolid lithium-ion battery cells

A new company called 24M emerged from stealth mode with a bold announcement of new semisolid lithium-ion battery, which will cost 50% less than today’s lithium-ion batteries.

24M was founded in 2010 and since then raised $50 million in private capital. One of the co-founders is MIT’s Dr. Yet-Ming Chiang, who was also co-founder of A123 Systems.

24M believes that costs will be dramatically reduced by new design of the cells (below $100/kWh by 2020):

“Today, 24M emerged from stealth mode to introduce the semisolid lithium-ion cell, a revolutionary technology that solves the grand challenge of energy storage by enabling a new, cost-effective class of the lithium-ion battery. 24M’s semisolid lithium-ion is the most significant advancement in lithium-ion technology in more than two decades and combines an overhaul in battery cell design with a series of manufacturing innovations that, when fully implemented, will slash today’s lithium-ion costs by 50% and improve the performance of lithium-ion batteries. The technology will accelerate the global adoption of affordable energy storage.

Until now, the energy storage field has had two options to try to drive down costs – build massive and complex factories to produce lithium-ion batteries in high volumes or pursue entirely new chemistries that may never move from the lab to the commercial floor. With the invention of the semisolid lithium-ion battery, 24M presents a third option – work with the world’s preferred energy storage chemistry and unlock new opportunities for cost reductions through new cell design and manufacturing innovations. 24M’s platform is the most significant advancement in lithium-ion technology since its debut more than 20 years ago.”

Dr. Yet-Ming Chiang, 24M’s Chief Scientist said:

“The lithium-ion battery is a brilliant, enabling technology, but its economics are flawed. It’s prohibitively expensive; it’s cumbersome and inefficient to make; and today’s version is approaching the limits of its cost reductions. 24M has fixed the flaws. We’ve made the world’s favorite battery better, fundamentally changing its cost curve by designing a more elegant and simpler cell and then making the batteries the right way – the way they should have been made from day one.”

But the costs are not the only advantage, as it turns out.  More energy, better performance and easy recycling were mentioned.

Well, as we don’t see even the preliminary spec sheet of the cells, it’s hard to say whether those batteries will fit electric vehicles. We will watch 24M on the radar.

Reinvented Cell Design: Enabled by the Semisolid Thick Electrode

24M’s simple but breakthrough cell design is made possible by the semisolid thick electrode – a material science innovation originating in Dr. Chiang’s lab at MIT. Conventional lithium-ion battery cells have a large fraction of inactive, non-charge carrying materials – supporting metals and plastics – that are layered, one-on-top of the other, within a cell’s casing. Those inactive materials are expensive and wasteful. With the invention of the semisolid thick electrode, 24M eliminates more than 80% of these inactive materials and increases the active layer thickness over traditional lithium-ion by up to 5x. Using thick electrodes, the cell also stores more energy, bettering the performance of the battery as well as its cost.

Advanced Manufacturing Platform

The simplicity of 24M’s new cell design likewise begets a radically simplified advanced manufacturing process. The traditional method for making lithium-ion batteries takes days, is extremely capital-intensive and must run at high-volume to achieve economies of scale. 24M’s novel approach to manufacturing yields dramatic improvements:

  • From Days to Hours: Start to finish, 24M’s cell creation takes one-fifth of the time of a conventional battery. Because semisolid lithium-ion doesn’t require binding, drying, solvent recovery or calendaring, it removes entire steps in the manufacturing process.
  • Ultra-low Cost: While the removal of manufacturing steps certainly contributes to lower capex, eliminating the need for entire plants makes semisolid lithium-ion ultra-low cost. A 24M factory requires about one-tenth the investment of a conventional plant.
  • Flexible and Modular: Manufacturers can scale in small steps to match supply to demand, making lithium-ion cost effective even at low-volume production.
  • Environmentally Friendly: 24M’s solvent-free manufacturing platform creates the most easily recycled lithium-ion cell ever made.

“We give the architects of our energy future everything they love about lithium-ion at a cost they love too,” said Throop Wilder, 24M’s CEO. “Together, our inventions achieve what lithium-ion has yet to do – meet the ultra-low cost targets of the grid and transportation industries. By 2020 our battery costs will be less than $100 a kilowatt-hour (kWh). We’re emerging at the right time with the right technology.”

Since its founding in 2010, 24M has raised $50 million in private capital, closing Series A and B rounds, from Charles River Ventures, North Bridge Venture Partners and industrial partners. The company is also the recipient of a $4.5 million grant from the U.S. Department of Energy. 24M’s cells are currently undergoing customer trials with large, global integrators of power systems for the grid. The company now employs more than 50 people and runs a fully automated manufacturing line from its 32,000 square foot facility in Cambridge, Massachusetts.”

Categories: Battery Tech


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46 Comments on "24M Introduces Semi-Solid Lithium-Ion Battery Cell"

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No idea about the technology. But if it hits the price point of $100/kWh then EVs will become competitive with ICE vehicles. As to whether the cell will work in an EV, the design shown is large pouch, which is what everyone other than Tesla is using, so the size and higher energy density would suggest the answer is yes.

Lets’s a prototype. Until then, I’m not getting excited over another battery breakthrough.


“…with a series of manufacturing innovations that, when fully implemented, will slash today’s lithium-ion costs by 50%…”

Gotta watch out for those parenthetical phrases.

Not all “battery breakthroughs” are equal. This is like Sakti3 where the innovation relates to materials and manufacturing rather than the chemistry. Seems more likely to be real. Also these are not tiny cells, assuming at least some of the 10,000 cells they’ve made are of this size.

Yep. That reminds me, what ever happened to the magical Ryden dual carbon battery from one year ago? Weren’t they supposed to put it in a EV race car for testing?



No information on what it’s made of and no performance numbers, but there is a slick marketing video. That fits the profile of numerous scam companies.


Before throwing stepping the word “scam”, you might want


to take a minute to look into the credentials and accomplishments of the company founder and original backers.

Your logical fallacy is “appeal to authority”.


What do you think sophisticated investors make decisions based on for startups BLT? If you think it’s something other than relevant technical training and record of accomplishment, you’d be mistaken.

“Your logical fallacy is appeal to academic and technical expertise.” There, I fixed it for you.

The high smarts only helps in designing good scam/vaporware company. After all, you need to outsmart only few venture capitalists and you can make decent salary for yourself for several years. And meanwhile you can do what smart people want to do most, i.e. researching new technology with unlimited R&D budged without any pressure to return commercially viable results.

As someone who rode my shares of A123 all the way to the bankrupt bottom, I’m not sure that touting a link to that failed company is the best way to engender confidence in new investors.


If you don’t think that being the inventor of the well respected A123 Battery chemistry, and world class acedemic credentials in chemistry and an MIT professorship are relevant experience, would love to hear what you consider appropriate qualifications.

Hard to believe you think A123’s technical staff had anything to do with that company’s financial problems.

It’s worth noting that those cells are still highly sought after for their phenomena C rate and reliability (cycle life).

A123’s problems had to do with manufacturing and management problems, not problems in chemistry. Sell the tech to someone that can make it (LG, Panasonic, JCI, or Samsung) and hopefully one of these tech battery improvements will work.

Since they are touting reduced costs, you need to see a final product, not just a prototype cell. Presumably this announcement means that they are actively trying to recruit licensing partners. Either that or they are looking for more investors.

They’re out for the C round of funding. So yes they are looking for money.

Maybe they want Tesla to buy one assembly line for their R&D space in the empty Gigafactory-hull.
If Tesla engineers can convert the idea of thicker electrodes to the round cell design that could help in a cost reduction. Even if the cost likely does not fall in the maybe _slightly_ optimistic range… Even 1 % counts when talking about many GWh…

Tesla uses cylindrical cells because the mass manufacturing of them has been solved and well optimized over the last decade. If this truly solved the manufacturing problems of large format cells, Tesla wouldn’t work to transform them into cylindrical cells, they’d just change their pack designs to use them.

Sorry I forgot to predict that 24M might also go back to “stealth mode” after round C again, in order to come back from stealth mode to start round D with slightly more “information” or to stay in stealth mode forever like so many before…

I hope not.

The fact that Dr. Y T Chiang is a co-founder makes this slightly more likely to have some sort of product come to fruition in a reasonable timeframe but I have to admit that I am of the same mindset as most of the posters here.
Just show us the “money”.
That having been said, $100 a kWh by 2020 would be sweet.

To me, this is one of the most exciting innovations I’ve seen in batteries in a while, because it strives to eliminate a lot of inactive material from the battery. A new chemistry could have a cathode that is 2x as energy dense. The problem is that 50% of the battery weight is copper, aluminum, separators, and electrolyte. On top of that a higher percentage of the battery becomes anode material to equal the capacity of the new cathode material. So a cathode that is 2x more energy dense, results in a battery that is maybe 15% more energy dense. An equally important aspect of this is that it can reduce the size of the equipment and factory needed to manufacture cells. This is an essential step for widespread EV production. The gigafactory, planned to be the one of the largest factories in the world (of anything), can produce enough batteries to make the honda accord electric (talking volumes of cars). That’s great, but that’s one car (albeit a very popular one) from one manufacturer. There has to be (according to Tesla’s own CTO), 20 – 40 factories like the gigafactory to move the auto industry to mostly EVs. If… Read more »

This looks like the “Pouch cell” used in the Leaf, 4 to a module, 24 modules/pack. Think they have a ready made customer?

Is this supposed to be 50% less than the current batteries, or 50% less than Gigafactory batteries that are already supposed to cut the price by 30%?

Is the 50% reduction on top of the 14% historical reductions year over year price per kWh that commodity cells have been enjoying for over a decade and a half?

It sounds great and all, but they are talking in nice round numbers like “50%” and “2020”.

For me, the more round the numbers, the less likely they came out of the scientific wing of the company, and the more likely they are coming out of the marketing and/or investor relations side of the company.

They said $100/kWh. I’m not sure how much more specific you want them to be.

In the qz.com article JakeY posted:
By 2020, Chiang says, that will be down to about $85 (per kWh), 30% below where conventional lithium-ion batteries—whose cost is also dropping—may be by then.

Quick calculation shows that $85 is 30% less than $121.

As for the $100 number… See my previous comments about round numbers.


That’s a whole lot of VERY round numbers. Again, it just raises my suspicions that these are marketing numbers, not numbers from the scientists.

If these round numbers don’t bother your own personal sense of scientific rationality, then by all means feel free to invest.

This article has a lot more detail:

It says that the method is only suitable for stationary batteries, not cars. Presumably the semi-solid nature of makes it so it can’t withstand the vibration/shock of use in a car.

…or it has a low C-rate. When you have a thick electrode, it will take time for all the ions to move through that thickness, hence the low C-rate.

Also, to those that talk about rolling this into a cylindrical cell – look at the thicknesses involved. The whole cell will be nearly 1mm thick. That is not something you can just roll up into a 20mm cylinder.

But how much C-rate do you need? A123 cells have a 30C rating, some say they’re good over 50C. If batteries got down to $100/kWh, you could do a 200hp (150kW) car with 250 miles of range (~70kWh) and the drivetrain would probably cost about the same as 200hp ICE.
With that in mind, a 70kWh only needs to support 3C to comfortably supply power for a 150kW drivetrain.
30C -> 3C, 10x thicker electrode?

You need a big enough C-rate to superchage. You also need a high enough volumetric energy density to be able to fit them into a car to generate 150kW+ of energy to drive the car.

Even if its only solving the stationary energy problem (assuming it can last more than 1500 cycles) then thats fantastic.

regen braking requires sufficient C.

That’s a great article but I don’t understand why you say the batteries won’t work in EVs. The article explicitly says they will. What would not have worked was the flow battery, which was the original idea on which the company was founded. But the flow battery was discarded in favor of static batteries.

Doesn’t talk about C rates other than saying the first test cells remained stable through thousands of cycles. For a long range BEV you wouldn’t need a cell to last more than a thousand cycles.

It says this:
“This machine, to be available for sale in two years, would be for stationary electric batteries—used to power businesses, neighborhoods and utilities, rather than cars.”

The C-rate issue is in order to provide enough charging and discharging power for a given capacity pack that can fit in a car. This is a non-issue for stationary packs because you have the space to add a larger capacity and no weight limitations, but obviously space and weight matters in a car.

lots and lots of talk…..let’s see something for real for once!

Here we go with another gee-whiz lab battery that will be out in 2020 (five years).

Sell ’em in Springfield Mo and I’ll believe it.

Yawn, If only I got a nickel for every time some Asian chap promised me a battery breakthrough….

Yeah everyone here seems justifiably jaundiced.

Hopefully one of these articles’ peoples’ will at long last come up with a usable $100/kwh storage cell.

200 kwh (800 mile range vehicles – they did claim 40% lighter as well correct?) for $20,000? If that comes to pass in the next 5 years it would greatly help vehicle electrification, and negate a large amount of the need for public infrastructure charging.

From what I understand about 24M is they are re-thinking the manufacturing. Battery manufacturing is expensive and it is the way it is because of the legacy of magnetic tape manufacturing machines re-purposed for battery production. They have reduced the materials required as well as the reduced certain steps. I am really hopeful of this one, because its not about battery chemistry, but about gains during the manufacturing. They seem to be on the right track. Also, 24M promises to reduce the start-up cost for battery manufacturing from 100s of millions to 10s of millions.

You gotta remember that this price is just the cells. Don’t get it confused with the price of the battery pack in the car which includes cooling, battery management, strong shell for puncture resistance etc. Elon stated over a year ago that cell prices were already below $150/kwh.

Sounds awesome – if it’s true. That remains to be seen.

Just to throw in some more real reporting, the MIT Technology Review has a great profile on 24M. http://www.technologyreview.com/news/538741/exiting-stealth-mode-24m-takes-on-the-battery-industry/

I see a number of people posting comments here think this is the real McCoy. Well, I hope they’re right. Unfortunately, we’ve seen literally dozens of similar claims published over the past several years, and not a single one of them has yet led to any commercial product.

“My my top advice really for anyone who says they’ve got some breakthrough technology is please send us a sample cell. Okay? Don’t send us PowerPoint. Just send one cell that works with all appropriate caveats. That would be great. That sorts out the nonsense and the claims that aren’t actually true. Talk is super cheap. The battery industry has to have more B.S. in it than any industry I’ve ever encountered. It’s insane.” — Elon Musk

From what I’ve seen, this is a manufacturing technique, not tied to a chemistry. They have patents filed for LiFePO4 (what A123 used), but also for NMC (what everyone is going to) and Li-S (what everyone hopes to go to).

Improving the manufacturing process and reducing the non-active components in a cell are desirable goals. Unfortunately, in ‘The Powerhouse’ by Steve LeVine, he quotes a scathing criticism of Dr. Yet-Ming Chiang by former MIT professor John B Goodenough, father of the Lithium Ion cell. “For the third time—first with cobalt-oxide, then with manganese spinel, and now iron phosphate—Goodenough’s lab had produced a major lithium-ion cathode with commercial possibilities. An MIT professor named Yet-Ming Chiang began to fiddle with Goodenough’s idea and filed for his own patents. Asserting that his improvements had created yet another new material, Chiang and some partners launched A123, a Massachusetts-based battery company. His stated aim was to sell a version of the lithium-iron-phosphate battery for use in power tools and eventually motor vehicles. This established another legal front for Goodenough as Chiang’s company sought to persuade a European tribunal to strike down the old man’s patents, which it eventually did in 2008. The result was a free-for-all, one that reached an apex late in 2008 when Warren Buffett spent $230 million to buy 10% of BYD, a Chinese car company that announced a new lithium-iron-phosphate-powered electric car. No one spoke of the source of BYD’s batteries… Read more »