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Launch HN: Saratoga Energy (YC W19), Better Carbon Nanotubes from Carbon Dioxide
104 points by SaratogaEnergy on Mar 4, 2019 | hide | past | favorite | 51 comments
Hi HN,

I’m Drew, founder of Saratoga Energy (https://www.saratoga-energy.com). We make better carbon nanotubes at one-fifth the price. Carbon nanotubes are a form of nano-scale carbon fibers (5,000X thinner than human hair) with remarkably high strength, electrical conductivity, and thermal conductivity properties. This makes them useful in a variety of commercial applications.

Lithium-ion batteries designed for electric cars already use carbon nanotubes to reduce heat generation during charging and to improve electrical conductivity. This results in faster charging and improved battery life. However, the cost is so high ($300/kg) that battery manufacturers are forced to use the minimal amount, rather the optimal amount.

Our breakthrough in manufacturing cost enables battery manufacturers to use the optimal amount, allowing electric cars to safely recharge in 10 minutes or less. This could give electric cars the boost they need to replace gasoline engines.

The idea to start the company grew from an idea posed to me by my Dad back in 2012 - is there a way to transform carbon dioxide, a greenhouse gas, into something valuable? I thought this would be an exciting challenge because most carbon dioxide technologies at the time were focused on storing it in underground caverns or converting it into commodity chemicals where it would be difficult to profit without substantial government subsidies.

After reading an article about Tesla’s intentions to only source raw materials that were sustainably produced in North America, we settled on developing a low-cost electrochemical process to convert carbon dioxide into graphite. Graphite is an essential energy storage material used in lithium-ion batteries. After deciding on the product, my Dad and I put together a small team of chemical engineers to help with the patents and applications for grants from the Department of Energy and the National Science Foundation.

When we received our funding, we began work with Lawrence Berkeley National Laboratory to construct small batteries to test the material we had made. We noticed that some cells would charge three, or sometimes five times faster than commercial reference materials. So we pulled the cells apart to have a look at the graphite with a high-powered microscope. All of the fast-charging graphite was matted with tiny hairs (I later learned that it sounds cooler if you call them “carbon nanotubes”).

We thought about it for a few days and did some research. We eventually figured out that certain metals we had tested in our production process were likely responsible for the growth of carbon nanotubes. So we isolated those metals to test the theory. It worked!

Now we had a process that could either grow carbon nanotubes or graphite - both at an estimated cost under $5/kg. The difference being that the market price for battery-grade graphite is $10/kg and the market price for battery-grade carbon nanotubes is $300/kg.

If the price of graphite is reduced from $10/kg to $5/kg, electric cars get a bit less expensive and the market expands a bit more. If the price of carbon nanotubes is reduced from $300/kg to $5/kg, electric cars cold potentially charge in about the same amount of time it takes to refill a tank of gas, which could create exponential growth in the electric car market. We discussed this with our grant manager and agreed that it made sense to pivot and scale up the carbon nanotube process - which leaves us here today in W19.

What’s different about our technology is that we produce carbon nanotubes through the electrolysis of molten carbonate salts. The electrochemical reaction produces carbon (nanotubes), oxygen gas, and metal oxides, which are further reacted with carbon dioxide to re-generate the carbonate salt starting material. So the net reaction is the input of energy to drive the conversion of carbon dioxide to carbon nanotubes and oxygen.

Industry has been using chemical vapor deposition to make carbon nanotubes since they were first discovered in 1991. We believe that our platform is better for a few reasons: 1) electrochemistry is tunable and this gives us control over the size and shape of the nanotubes, so they can be custom-tailored for specific battery chemistries and applications outside of energy storage as well; 2) the energy requirement for our manufacturing process is estimated to be 27 kWh/kg, five times less energy intensive than chemical vapor deposition; and 3) our technology represents a value-added use for carbon dioxide, and if powered by electricity from renewable sources, would have a negative carbon footprint.

I think the reason nobody has commercialized this production method yet, or come up with some other high-efficiency process, is because chemical vapor deposition is relatively simple to operate and relatively simple to scale. Billions of dollars worth of chemical vapor deposition infrastructure are already established, and historically, there haven’t been many new market opportunities that would justify investing in new technologies to drive down cost.

Only recently have researchers demonstrated the potential for carbon nanotubes to improve the performance of new applications like advanced energy storage, high-strength carbon fibers and composites, lightweight electrical wiring, and concrete composites for roads that don’t crack. If carbon nanotubes were less expensive, these new applications could be worth billions while also creating sizable reductions in greenhouse gas emissions. It is our mission to bring new markets like these to life and to develop new products that best take advantage of what our carbon nanotubes have to offer.

I believe that we are best positioned to break this cost-curve and bring this technology to market because molten carbonate electrochemistry is not a well-known science. What we’ve learned since our foundation in 2012 is not commonly taught in universities. Our knowledge was acquired through hands-on experience and in-house development of intellectual property.

Hopefully some of you folks are also interested in carbon nanotubes, or at least share a mutual dislike for carbon dioxide. I’m looking forward to sharing some ideas with everyone!


So how are you guys and the rest of the industry going to manage the possible toxicity of carbon nanotubes?[1] It seems they get into people's lungs and then they never leave and cause mechanical damage much like asbestos presumably leading to difficult to treat cancers. Are you going to wait for these things to be in just about everything and then spend the next 50 years getting sued?


only certain types of carbon nanotubes that have a thick and rigid structure have asbestos-like qualities. These are no longer used outside of Asia. The thinner, flexible variety similar to the ones we make do not share these qualities an do not penetrate cell tissue. Similar to carbon black, which is a widely used nano-material in car tires. Carbon nanotubes are also sold in solution and in dispersion so they cannot easily become air born.

Amazing story, very inspirational to those of us just working on CRUD apps.

Who is your father and what is his career background? I see he was instrumental in putting you on this path. This was the quote that stuck out to me:

> “After deciding on the product, my Dad and I put together a small team of chemical engineers to help with the patents and applications for grants from the Department of Energy and the National Science Foundation.

How much capital did you two have to risk at this stage to pay your team before receiving the grants?

Thank you! My father is an awesome guy with a unique perspective on the future! I'd rather not get specific, but having an initial angel investor was crucial for us to be able to generate the amount of data we needed to win our first grant an keep things moving forward.

I felt your idea so interesting and after searched a bit I found similar idea as below. Could you explain the difference? https://www.sciencedirect.com/science/article/pii/S019689041...

> Our breakthrough in manufacturing cost enables battery manufacturers to use the optimal amount, allowing electric cars to safely recharge in 10 minutes or less.

Well that's half the battle. The other half of the problem is delivering that amount of energy in 10 minutes, particularly in areas that are already maxing out their capacity on hot summer days.

Agreed. That is definitely a problem that needs some attention. There is a big research effort going on at the Department of Energy "Enabling Extreme Fast Charging" that is providing funding for solutions to fast charging from the battery performance end and from the charging infrastructure ends. Hopefully industry finds some solution sooner rather than later. https://www.energy.gov/eere/vehicles/downloads/enabling-extr...

My math may be a bit off but if you have a 230Ah battery (Telsa Model 3) and you want to charge it in 10 minutes you need something on the order of 1380A charging current even ignoring losses. At 350V, the voltage of the Tesla Model 3 battery pack, this is 483,000 Watts! There are major problems with this type of charging happening at scale at every level of the energy grid.

Most systems like this would be changed to go battery to battery with larger stationary storage on-site being essentially refilled from the net at the average use rate of all cars combined per day. This would delay this problem a little

This is for sure a tough challenge. I think supercharging stations charge at 400V and 250A for the model S. Porsche and others also have 800V chargers coming online.

To be honest I wouldn't mind having just half of that power.

Every quarter I do a 1500km trip, which is split into two legs - the longer being around 1140km.

Assuming I started with enough charge to drive 300km, charging wouldn't affect my time, because I am human and need to go to the bathroom, eat etc.

Hi Drew! What you're doing sounds awesome -- more power to you, both figuratively and literally! Hey, I'd love to see an "About Us" web page on your website with team bio's, list of VC's, etc. (Hey, you've already written half of that page in what you've posted here!). Also, please ignore the naysayers here. Everyone in history who has tried to advance science has always had naysayers, it's just the nature of what you're trying to do! Good luck, and I hope you succeed wildly!

Haha, thank you! Our site definitely needs an update. We have a more detailed website in the works! I'll keep you posted!

Hi Drew! You are Doing Ground Breaking work here,I wish you all the Success. If you need any help in developing website,It would be my pleasure to do so,you can find my email in bio.

Awesome. Thank you!

There seems to be a growing concern wrt HSE aspects of CNTs. Is that an issue you're worried about (as in - worried about a possible regulatory shift)

The health concerns mostly related to air born nano-materials dust. We plan to distribute the product in a way that minimizes these concerns. Current CNT producers reduce this risk by selling their products in solution or pre-dispersed into a host matrix (like plastic) so no dust can be created. Also, morphology plays a big role in health. If the cnts produced look like needles, this is similar to asbestos. Not good. If you produce CNTs that look more like spaghetti, they cannot penetrate tissue and are less of a concern. These are the type that we are focused on.


HSE is health and Safety. I'm not sure what the 'E' stands for :)

E = Executive [1]

They're considering the possibility that CNTs pose specific health concerns (kind of like asbestos from what I understand), which would create quite a few regulatory changes in both production and usage.


Environment :)

Have you heard of Molecular Rebar? http://www.molecularrebar.com/

Their CNT patent portfolio is being licensed by a company called Black Diamond Structures, which is a joint venture with SABIC. They’re looking at battery applications.

Thanks for the tip! I've heard that Molecular Rebar and Black Diamond Structures have a great process to untangle and purify CNTs. I believe their business model is to buy low cost CNTs from other producers and upgrade them with their process. Maybe there's an opportunity for collaboration.

Happy to make an intro. My email is in my profile.

that would be awesome. thank you! ill send you an email.

Can you selectively grow semiconducting tubes, or metallic tubes, or do you only get a mixture of semiconducting and metallic?

We grow conductive multi-walled carbon nanotubes. Some of the layers may be semi-conductive. But in bulk they are a conductive material. We haven't refined the process to the point where we can select for conductivity type yet.

I believe there is a competition to develop a method to collect carbon dioxide and turn it into something useful. Did you won that competition? This seems really promising and better than collecting CO2 and just dumping it underground.

There is the Carbon XPrize but I think they are a year out from announcing winners.

There is a team using Molten Carbonate Electrolysis to create Carbon Nano-tubes in the competition. It sounds like the are not related based on the 2012 starting date in the post. The team lead has been working on this for 30 years.

We weren't ready to apply to the carbon xprize when it was announced. But we're ready to scale quickly with Y Combinator!

Who are the main suppliers now at the higher price points?

The main suppliers are Showa Denko, Nanocyl, Arkema, and Cnano. Their prices range from $75/kg to $300/kg.

Good luck!

How big do you see this carbon nanotube market being, and thus how much net CO2 do you see yourself removing from the environment?

thanks! in the case of the cement market, carbon nanotubes have been used in 1% concentration to improve the lifespan of cement. 4 billion tons of cement are produced every year. If carbon nanotubes where used in all new cement mixtures, that would be 40 million tons of carbon nanotubes per year, which would consume 148 million tons of CO2 per year. But perhaps more importantly, carbon nanotubes would reduce the replacement frequency of cement structures. cement production is one of the largest industrial sources of carbon dioxide emissions.

I love this area of technology and the scale of your vision. For the battery application, do you need to use only electrically conducting nanotubes? Is your 27kWh per kg number for single-walled electrically conducting nanotubes? Do you need to filter out semi-conducting nano-tubes?

I think that the improvements to batteries will have a better value proposition than strengthening concrete, though perhaps you can get away with less filtering requirements for non-electrical applications. How much does this strengthening increase the life-time-value of the concrete? Concrete is under $100 per ton (poured cost, 50% of which is dry materials), and it seems like you're talking about 50% - 150% increased cost.

At scale, you are talking about ((40 billion kg) * 27 * (kWh per kg)) / (1 year) = 123.205917 gigawatts -- to makes 1267 kg of nanotubes per second for 40 million tons of carbon nanotubes per year. 123 GW almost certainly means hundreds of billions of dollars invested in power infrastructure for the purposes of carbon nanotube production for concrete. If you expect to scale with sustainability in mind, you should consider designing your entire reaction around the renewable energy source. Perhaps you can employ similar catalytic processes to the Co-Mo-S photo-hydrogenation from sunlight to achieve higher efficiency per area by using sunlight more directly.

We like the battery idea the best as well. We've chosen that as our first product to market. Me make multi-walled carbon nanotubes which are conductive in bulk. Its possible that there are non-conductive layers, but they are encased by conductive layers that counter act them. For concrete i've sen research showing 50% improvement in strength with 1% carbon nanotube concentration. We haven't confirmed this ourselves yet, but we are starting up a testing program soon. We are also planning on scaling with renewables like hydroelectric. If in the future carbon nanotubes can be used to replace aluminum as a structural material, there may be an opportunity to use they hydroelectric they were once operating on to power the process. But I agree, to reach a massive scale, we will need massive renewable energy. But I think we need that anyway!

Cool; so about 0.35% of yearly world production of CO2 per year from capture, and assuming 25% increased longevity, somewhere a little short of 1% due to cement reduction.

... that's pretty good, actually, might buy us another year, on its own...

maybe it'll buy us some time to figure out fusion! I think if we can get the electric car market to a more significant level as well (and power them on renewables) that would also have a big impact.

How long are the continuous fibers? CNTs can do some truly insane things if you make them long enough.

The CNTs we are making right now are about 10-20 microns long. Making them longer is a focus area for us. However, the nano-materials department at Rice has created a wet-spinning process the can bundle CNTs into continuous fiber. They aren't quite a strong as a continuous CNT from what i've heard, but still stronger than carbon fiber. https://www.youtube.com/watch?v=4XDJC64tDR0

Have you characterized the anisotropy of the fibers yet? Mechanical, electrical, or otherwise?

Also thank you for the response!

Why CO2 instead of CH4? If someone else tries a similar process with CH4, will their cost be smaller?

we use CO2 because it easily absorbs into our electrolyte and ch4 does not. ch4 is also flammable at the temperatures we operate at and this would be more difficult to design around.

Are you hiring mechanical engineers?

If all goes well at demo day we'll be looking for mechanical engineers! Please send your info!

Can randoms purchase a Kg of CNTs from you to experiment with?

Yes they can. Always looking for new applications!

I live in The bay area, can i pickup? And what is the cost for a Kg of CNTs?

super cool! are yall hiring materials scientists? :)


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