Why Did Elon Musk Spend $218 Million (in stock) on an Ultracapacitor Company? The Answer may be in ‘Dry Electrode Technology’

Tesla_ElectricVehicles_XL_721_420_80_s_c1 (1)          Does Tesla want ultracapacitors? Or dry electrode technology?

Earlier this month, Tesla announced plans to acquire Maxwell Technologies, an established, 380-employee ultracapacitor and storage materials firm for $218 million in an all-stock deal. It’s easy for a transaction of this sort to get lost in the Tesla media cycle.


Elon Musk was once intent on studying ultracapacitors at Stanford University, long before Tesla was even a gleam in his eye. Apparently, Musk is still charged up on the technology.

Maxwell’s total revenue was $91.6 million in the first nine months of 2018, with losses of $30.2 million. Revenue in 2017 was $130.3 million with losses of $43.1 million.

So why is Tesla paying above book value (but still not enough, according to some investors) for a money-losing firm (here’s Maxwell’s SEC filing)?

Does Tesla want ultracapacitors?

Maxwell’s core business is ultracapacitors, the wide-temperature-range, high-power-density energy storage component that can rapidly charge and discharge. Also known as supercaps or electronic double layer capacitors, ultracapacitors are geared for high-power and high-cycle applications.

Batteries use a chemical process to store energy, while ultracapacitors store a static electric charge — physically separating positive and negative charges.

Maxwell’s ultracaps deliver peak power as well as regenerative braking, voltage stabilization, backup power and hybrid stop/start. Ultracaps are also used to power the pitch control adjustment in wind turbines during sudden wind speed changes, since replacing batteries at 500 feet above the ground is tricky.

In a previous interview, Maxwell’s CEO estimated that there is $5,000 worth of ultracaps in the typical wind turbine and $15,000 per electric bus. Maxwell declined to respond to GTM to update those figures.

Or dry electrode technology?

But Maxwell’s allure might not be its ultracapacitors — it might be the dry electrode technology developed by Maxwell that really intrigues Elon Musk.

The “dry” in “dry electrode technology” refers to an ultracapacitor manufacturing process that Maxwell claims can improve battery costs, performance and lifetime across a variety of lithium-ion battery chemistries. 

Maxwell states, in a release, that its dry electrode manufacturing technology, historically used to make ultracapacitors, is “a breakthrough technology that can be applied to the manufacturing of batteries.”passive-dry-electrode-schematic_Q320

white paper from Maxwell claims that its dry battery electrode (DBE) coating technology can be used with “classical and advanced” lithium-ion battery chemistries, but “unlike conventional slurry cast wet coated electrode, Maxwell’s DBE produces a thick electrode that allows for high energy density cells with better discharge rate capability than those of a wet coated electrode.” (Right: Passive dry electrode schematic)

presentation from the company claims it has “demonstrated” an energy density of greater than 300 watt-hours per kilogram and has “identified” a path to greater than 500 watt-hours per kilogram. Maxwell claims to have used the process with a number of available anode materials.

A battery expert colleague notes that solvent-free electrode manufacturing “might be worth $200 million” if Maxwell “has really eliminated the toxic solvent without compromising on performance.” Maxwell’s patent filings indicate that work is being done to eliminate solvent usage in both dry-processing and melt-processing of binders.

Other ultracap suppliers include TokinSeikoEatonCAP-XXLS UltracapacitorIoxus and Skeleton.

This deal was Tesla’s fifth acquisition since its founding; the others being manufacturing-automation firm PerbixSolarCityRiviera Tool and Grohmann Engineering.

During Maxwell’s third-quarter 2018 conference call, CEO Franz Fink noted that its dry electrode business was looking for a partner to provide “significant financial support” and expertise in EVs or energy storage systems. 

If this deal goes through in the coming quarters, Maxwell’s CEO will have gotten his wish.

Story from GTM (GreenTechMedia) – Eric Wescoff


New applications for Ultra(super)Capacitors ~ Startup’s energy-storage devices find uses in drilling operations, aerospace applications, electric vehicles.


FastCAP Systems’ ultracapacitors (pictured) can withstand extreme temperatures and harsh environments, opening up new uses for the devices across a wide range of industries, including oil and gas, aerospace and defense, and electric vehicles. Courtesy of FastCAP Systems

Devices called ultra-capacitors have recently become attractive forms of energy storage: They recharge in seconds, have very long lifespans, work with close to 100 percent efficiency, and are much lighter and less volatile than batteries. But they suffer from low energy-storage capacity and other drawbacks, meaning they mostly serve as backup power sources for things like electric cars, renewable energy technologies, and consumer devices.

But MIT spinout FastCAP Systems is developing ultracapacitors, and ultracapacitor-based systems, that offer greater energy density and other advancements. This technology has opened up new uses for the devices across a wide range of industries, including some that operate in extreme environments.

Based on MIT research, FastCAP’s ultra-capacitors store up to 10 times the energy and achieve 10 times the power density of commercial counterparts. They’re also the only commercial ultra-capacitors capable of withstanding temperatures reaching as high as 300 degrees Celsius and as low as minus 110 C, allowing them to endure conditions found in drilling wells and outer space. Most recently, the company developed a AA-battery-sized ultra-capacitor with the perks of its bigger models, so clients can put the devices in places where ultra-capacitors couldn’t fit before.

Founded in 2008, FastCAP has already taken its technology to the oil and gas industry, and now has its sights set on aerospace and defense and, ultimately, electric, hybrid, and even fuel-cell vehicles. “In our long-term product market, we hope that we can make an impact on transportation, for increased energy efficiency,” says co-founder John Cooley PhD ’11, who is now president and chief technology officer of FastCAP.

FastCAP’s co-founders and technology co-inventors are MIT alumnus Riccardo Signorelli PhD ’09 and Joel Schindall, the Bernard Gordon Professor of the Practice in the Department of Electrical Engineering and Computer Science.

A “hairbrush” of carbon nanotubes

Ultracapacitors use electric fields to move ions to and from the surfaces of positive and negative electrode plates, which are usually coated with a porous material called activated carbon. Ions cling to the electrodes and let go quickly, allowing for quick cycling, but the small surface area limits the number of ions that cling, restricting energy storage. Traditional ultracapacitors can, for instance, hold about 5 percent of the energy that lithium ion batteries of the same size can.

In the late 2000s, the FastCAP founding team had a breakthrough: They discovered that a tightly packed array of carbon nanotubes vertically aligned on the electrode provided much more surface area. The array was also uniform, whereas the porous material was irregular and difficult for ions to move in and out of. “A way to look at it is the industry standard looks like a nanoscopic sponge, and the vertically aligned nanotube arrays look like a nanoscopic hairbrush” that provides the ions more efficient access to the electrode surface, Cooley says.

With funding from the Ford-MIT Alliance and MIT Energy Initiative, the researchers built a fingernail-sized prototype that stored twice the energy and delivered seven to 15 times more power than traditional ultracapacitors.

In 2008, the three researchers launched FastCAP, and Cooley and Signorelli brought the business idea to Course 15.366 (Energy Ventures), where they designed a three-step approach to a market. The idea was to first focus on building a product for an early market: oil and gas. Once they gained momentum, they’d focus on two additional markets, which turned out to be aerospace and defense, and then automotive and stationary storage, such as server farms and grids. “One of the paradigms of Energy Ventures was that steppingstone approach that helped the company succeed,” Cooley says.

FastCAP then earned a finalist spot in the 2009 MIT Clean Energy Prize (CEP), which came with some additional perks. “The value there was in the diligence effort we did on the business plan, and in the marketing effect that it had on the company,” Cooley says.

Based on their CEP business plan, that year FastCAP won a $5 million U.S. Department of Energy (DOE) Advanced Research Projects Agency-Energy grant to design ultracapacitors for its target markets in automotive and stationary storage. FastCAP also earned a 2012 DOE Geothermal Technologies Program grant to develop very high-temperature energy storage for geothermal well drilling, where temperatures far exceed what available energy-storage devices can tolerate. Still under development, these ultracapacitors have proven to perform from minus 5 C to over 250 C.

From underground to outer space

Over the years, FastCAP made several innovations that have helped the ultracapacitors survive in the harsh conditions. In 2012, FastCAP designed its first-generation product, for the oil and gas market: a high-temperature ultracapacitor that could withstand temperatures of 150 C and posed no risk of explosion when crushed or damaged. “That was an interesting market for us, because it’s a very harsh environment with [tough] engineering challenges, but it was a high-margin, low-volume first-entry market,” Cooley says. “We learned a lot there.”

In 2014, FastCAP deployed its first commercial product. The Ulysses Power System is an ultracapacitor-powered telemetry device, a long antenna-like system that communicates with drilling equipment. This replaces the battery-powered systems that are volatile and less efficient. It also amplifies the device’s signal strength by 10 times, meaning it can be sent thousands of feet underground and through subsurface formations that were never thought penetrable in this way before.

After a few more years of research and development, the company is now ready to break into aerospace and defense. In 2015, FastCAP completed two grant programs with NASA to design ultracapacitors for deep space missions (involving very low temperatures) and for Venus missions (involving very high temperatures).

In May 2016, FastCAP continued its relationship with NASA to design an ultracapacitor-powered module for components on planetary balloons, which float to the edge of Earth’s atmosphere to observe comets. The company is also developing an ultracapacitor-based energy-storage system to increase the performance of the miniature satellites known as CubeSats. There are other aerospace applications too, Cooley says: “There are actuators systems for stage separation devices in launch vehicles, and other things in satellites and spacecraft systems, where onboard systems require high power and the usual power source can’t handle that.”

A longtime goal has been to bring ultracapacitors to electric and hybrid vehicles, providing high-power capabilities for stop-start and engine starting, torque assist, and longer battery life. In March, FastCAP penned a deal with electric-vehicle manufacturer Mullen Technologies. The idea is to use the ultracapacitors to augment the batteries in the drivetrain, drastically improving the range and performance of the vehicles. Based on their wide temperature capabilities, FastCAP’s ultracapacitors could be placed under the hood, or in various places in the vehicle’s frame, where they were never located before and could last longer than traditional ultracapacitors.

The devices could also be an enabling component in fuel-cell vehicles, which convert chemical energy from hydrogen gas into electricity that is then stored in a battery. These zero-emissions vehicles have difficulty handling surges of power — and that’s where FastCAP’s ultracapacitors can come in, Cooley says.

“The ultra-capacitors can sort of take ownership of the power and variations of power demanded by the load that the fuel cell is not good at handling,” Cooley says. “People can get the range they want for a fuel-cell vehicle that they’re anxious about with battery-powered electric vehicles. So there are a lot of good things we are enabling by providing the right ultra-capacitor technology to the right application.”

Carbon doped with nitrogen dramatically improves storage capacity of supercapacitors

Carbon Doped Super Capacitors 56814eee6e72e


A team of researchers working in China has found a way to dramatically improve the energy storage capacity of supercapacitors—by doping carbon tubes with nitrogen. In their paper published in the journal Science, the team describes their process and how well the newly developed supercapacitors worked, and their goal of one day helping supercapacitors compete with batteries.

Like a , a capacitor is able to hold a charge, unlike a battery, however, it is able to be charged and discharged very quickly—the down side to capacitors is that they cannot hold nearly as much charge per kilogram as batteries. The work by the team in China is a step towards increasing the amount of charge that can be held by supercapacitors (capacitors that have much higher capacitance than standard capacitors—they generally employ carbon-based electrodes)—in this case, they report a threefold increase using their new method—noting also that that their supercapacitor was capable of storing 41 watt-hours per kilogram and could deliver 26 kilowatts per kilogram to a device.

The new supercapacitor was made by first forming a template made of tubes of silica. The team then covered the inside of the tubes with carbon using and then etched away the silica, leaving just the carbon tubes, each approximately 4 to 6 nanometers in length. Then, the carbon tubes were doped with nitrogen atoms. Electrodes were made from the resulting material by pressing it in powder form into a graphene foam. The researchers report that the doping aided in chemical reactions within the supercapacitor without causing any changes to its electrical conductivity, which meant that it was still able to charge and discharge as quickly as conventional supercapcitors. The only difference was the dramatically increased storage capacity.

Because of the huge increase in , the team believes they are on the path to building a supercapacitor able to compete directly with batteries, perhaps even . They note that would mean being able to charge a phone in mere seconds. But before that can happen, the team is looking to industrialize their current new , to allow for its use in actual devices.

Explore further: Researchers find ordinary pen ink useful for building a supercapacitor

More information: T. Lin et al. Nitrogen-doped mesoporous carbon of extraordinary capacitance for electrochemical energy storage, Science (2015). DOI: 10.1126/science.aab3798

Carbon-based supercapacitors can provide high electrical power, but they do not have sufficient energy density to directly compete with batteries. We found that a nitrogen-doped ordered mesoporous few-layer carbon has a capacitance of 855 farads per gram in aqueous electrolytes and can be bipolarly charged or discharged at a fast, carbon-like speed. The improvement mostly stems from robust redox reactions at nitrogen-associated defects that transform inert graphene-like layered carbon into an electrochemically active substance without affecting its electric conductivity. These bipolar aqueous-electrolyte electrochemical cells offer power densities and lifetimes similar to those of carbon-based supercapacitors and can store a specific energy of 41 watt-hours per kilogram (19.5 watt-hours per liter).


McMaster University Develops Lightweight, High Density (Power) and Faster Recharging Nano- Cellulose Material: Applications in Wearable Devices, Portable Power Sources and Hybrid Vehicles

McMaster Cellulose 151006132027_1_540x360McMaster University: Summary: New work demonstrates an improved three-dimensional energy storage device constructed by trapping functional nanoparticles within the walls of a foam-like structure made of nanocellulose. The foam is made in one step and can be used to produce more sustainable capacitor devices with higher power density and faster charging abilities compared to rechargeable batteries. This development paves the way towards the production of lightweight, flexible, and high-power electronics for application in wearable devices, portable power sources and hybrid vehicles.

McMaster Engineering researchers Emily Cranston and Igor Zhitomirsky are turning trees into energy storage devices capable of powering everything from a smart watch to a hybrid car.

The scientists are using cellulose, an organic compound found in plants, bacteria, algae and trees, to build more efficient and longer-lasting energy storage devices or supercapacitors. This development paves the way toward the production of lightweight, flexible, and high-power electronics, such as wearable devices, portable power supplies and hybrid and electric vehicles.

“Ultimately the goal of this research is to find ways to power current and future technology with efficiency and in a sustainable way,” says Cranston, whose joint research was recently published in Advanced Materials. “This means anticipating future technology needs and relying on materials that are more environmentally friendly and not based on depleting resources.

Cellulose offers the advantages of high strength and flexibility for many advanced applications; of particular interest are nanocellulose-based materials. The work by Cranston, an assistant chemical engineering professor, and Zhitomirsky, a materials science and engineering professor, demonstrates an improved three-dimensional energy storage device constructed by trapping functional nanoparticles within the walls of a nanocellulose foam.

The foam is made in a simplified and fast one-step process. The type of nanocellulose used is called cellulose nanocrystals and looks like uncooked long-grain rice but with nanometer-dimensions. In these new devices, the ‘rice grains’ have been glued together at random points forming a mesh-like structure with lots of open space, hence the extremely lightweight nature of the material. This can be used to produce more sustainable capacitor devices with higher power density and faster charging abilities compared to rechargeable batteries.

Lightweight and high-power density capacitors are of particular interest for the development of hybrid and electric vehicles. The fast-charging devices allow for significant energy saving, because they can accumulate energy during braking and release it during acceleration.

“I believe that the best results can be obtained when researchers combine their expertise,” Zhitomirsky says. “Emily is an amazing research partner. I have been deeply impressed by her enthusiasm, remarkable ability to organize team work and generate new ideas.”

Story Source:

The above post is reprinted from materials provided by McMaster University. Note: Materials may be edited for content and length.

Journal Reference:

  1. Xuan Yang, Kaiyuan Shi, Igor Zhitomirsky, Emily D. Cranston. Cellulose Nanocrystal Aerogels as Universal 3D Lightweight Substrates for Supercapacitor Materials. Advanced Materials, 2015; DOI: 10.1002/adma.201502284
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