This morning, Cambridge, Mass.-based battery company 24M emerged from
stealth mode after four-and-a-half years of improving its technology
and lining up investors and strategic partners. 24M brings two new things to the table with its semisolid lithium ion
battery: the technology itself, which is cheaper and environmentally
more benign (solvent-free and more easily recycled); and the potential
promise of dramatically reshaping the economics of lithium ion battery
manufacturing.
In a conversation today, Throop Wilder, Co-Founder and CEO, and Dr.
Yet-Ming Chiang, Co-Founder and Chief Scientist, filled me in on the
details, and why this matters. Chiang observes that the lithium ion battery has been around a while,
having first been commercialized in 1991, and that although there have
been significant improvements along the way, the manufacturing process
has not fundamentally changed. The current approach is to start with a
wet ink of active materials, paint it onto a thin metal foil, dry it
out, and then put it under extreme pressure. The pieces are then cut and
assembled, after which liquid electrolyte is added. The high speed
drying process takes place on a reel-to-reel manufacturing line that may
be hundreds of feet long. Which means you need very large and expensive
factories.
Chiang comments that the underlying lithium ion chemistry possesses
many advantages, and the lithium itself is not expensive. The high cost
of today’s batteries has to do more with the way the cells are designed
and manufactured.
If you dissect a typical cell today, you find many thin layers. In a millimeter there are about 25 discrete layers. And a lot of that is because initially it was necessary to make these electrodes very thin in order to charge and discharge in a reasonable amount of time.
What 24M did was to change by using semi-solid lithium ion, whose
consistency Chiang compares to peanut butter, so that a much thicker
electrode can be utilized for similar performance.
In our case, if you compare the two side by side, in one millimeter we have only five layers, and the vast majority is the energy storing electrode…we take out about 80% of the inactive material content.
Image: 24M – better to be thick than thin
The result? A significantly lower cost per cell.
The 24M design also avoids drying altogether, which reduces the size
of the factory required, since one doesn’t need these lengthy
reel-to-reel drying spaces. This process reduces the time required by
about 80%, which in turn completely changes the economics of
manufacturing. It allows for a more modular and less capital-intensive
approach. Chiang claims that not only will the 24M approach reduce
Li-ion battery costs to 50% of today’s costs when it is fully deployed,
but it could also fundamentally change the entire cost structure of the
industry.
In a conventional lithium ion process, you have to spend a billion dollars to get into the game, because of the complex process. In order to have high speed you have to be able to dry electrodes before they are wound up, which means long lines and large plant size.
Chiang suggests that instead of a minimum investment of a billion
dollars, one might be able to build a much smaller modular plant (with
lower output, of course) in the tens of millions of dollars, perhaps as
low as $12 million. If you perfect the design and development of that
modular mini-plant, you can quickly scale up production.
It’s a modular manufacturing approach. It’s like a very efficient desktop printer versus a printing press.
CEO Wilder states that 24M has raised $50 million in private
investment in Series A and B rounds from a combination of venture
capital firms Charles River Ventures and North Bridge Venture Partners,
as well as a number of large strategic industrial partners. These
include an unnamed global manufacturer that is working on design of the
small-scale manufacturing plants 24M intends to deploy, IHI – a Japanese industrial manufacturing company that constructs and owns power plants, and PPT – Thailand’s former state-owned oil and gas company.
The latter company invested because “they are starting to build power
plants they want to integrate with storage…so we have a nice complement
of manufacturing and customers in our strategic partners. “
Wilder notes that the company is embarking on a Series C round of financing as well.
The timeline we are on is we have an automated low volume pilot plant in Cambridge, Massachusetts. We are developing a high volume plant right now for mid 2017, but we haven’t decided yet on a location.
The company boasts 8 ‘broad’ patents issued with “75 more in flight”
and almost 10,000 cells built so far in Cambridge. One clearly stated
objective is to sustain a technological advantage, even as designs
change and innovation in the industry occurs. Wilder observes that
continued evolution is inevitable, and the company’s platform is
designed to accommodate anticipated future change. In other words, a
large number of lithium ion chemistries can be turned into semi-solid
materials utilized in the manufacturing process.
It takes advantage of any lithium ion chemistry, as well as the full power of the lithium ion supply chain, and it’s ready for new lithium ion chemistries as they become available. It’s not a new chemistry – it’s a platform encompassing cell design so it’s a much simpler cell design and manufacturing process.
So with all the innovation to come, did Tesla put a stake in the
ground too soon with its multi-billion dollar factory, investing in a
manufacturing process that may someday become obsolete?
Chiang answers diplomatically.
If we, the industry, are successful in bringing down costs and increasing adoption you are going to need a lot more giga-factories…there will be change – we represent that. There will be better ways to manufacture batteries. As long as we are headed in the right direction with a huge and growing market, that will take care of a lot of it.
At the end of the day, Chiang observes that much of the lithium ion
battery industry is essentially hostage to its past, and needed to be
reinvented.
If we were to start today with a clean sheet of paper, we would want a technology with high energy density, great round trip efficiency, and fundamentally low chemistry cost. We wouldn’t do it the way it’s being done. We would do something much more streamlined and efficient, which is what 24M is doing.
Obviously, there is a good distance to go between the current
incarnation and an entity that revolutionizes the industry. But the
company has solid investors and serious partners. 24M will be
worth watching in the years to come.
Image: 24M – this bears watching closely
http://www.forbes.com/sites/peterdetwiler/2015/06/22/24m-a-lithium-ion-battery-breakthrough-technology/2/?ss=energy