Solid-State Battery 3D Printing Preps for Production
Michael Molitch-Hou posted on September 10, 2019 |
Silicon Valley startup KeraCel is developing technology for producing batteries.

In many ways, the holy grail of additive manufacturing (AM) is the ability to produce completely fullyfunctional components and assemblies in a single fabrication operation—say, smartphones 3D printed with just one machine. Key to such a capability would be the ability to 3D print complete batteries, a project that a variety of researchers have been working on around the globe.

Though there are a number of research endeavors to develop battery 3D printing technology, KeraCel may be the first company capable of commercializing it. To learn more, we spoke to Arwed Niestroj, chief operating officer of KeraCel, who was able to tell us about the startup’s plan for mass manufacturing solid-state batteries, including the lithium-ion variety, using AM.

How to 3D Print Batteries

KeraCel is still holding its cards close to its chest, but Niestroj was able to divulge some significant information about the firm’s technology. Without going into too much detail, he did specify that KeraCel’s battery printing process is based on MIT’s powder-based binder technology, which the company is in the process of patenting.

Binder jetting is a process in which a liquid binding agent is deposited onto a bed of powder. This powder can be gypsum for making full-color models; sand for creating sand cores from which to cast metal parts; or metal.

Other unique developments related to binder jetting include 3D printing medicine and the fabrication of large-scale sand or gypsum components.

KeraCel has said that it can 3D print a complete battery within this single process, before the battery is finished in a furnace. This includes the anode, cathode and the electrolyte material through which the charged ions pass during the charging and discharging phases.

Traditional lithium-ion batteries are made up of a sheet of conductive material, a sheet of anode, a sheet of cathode and a separator (or “electrolyte”). Due to the roll-to-roll manufacturing process used in producing them, these sheets must have a minimum thickness so that they are sturdy and resistant enough to handle the mechanical forces in production.

KeraCel’s 3D printing system doesn’t have these same constraints.

“The big advantage is that we use much less material than is used in traditional batteries because we can print every layer much, much thinner than the current manufacturing tech will allow,” Niestroj said. “That makes it possible to produce batteries that have double the energy in the same volume. Or we can make a battery with the same amount of energy at half the cost because we’re using only half the material.”

Using KeraCel’s technology, it would be possible to create a battery that would give electric vehicles (EVs) double the typical range or a smartphone with double the usetime before a recharge would be necessary. In fact, the overall process is much less complex than traditional battery manufacturing, potentially dropping the cost of production further.

What makes these batteries solid-state is the fact that the electrolyte is not made of a liquid or gel material. Instead, the firm uses ceramic, which means that, unlike existing batteries on the market, there is no liquid that can heat up to the point of bursting the battery.

“The science in the battery community says that solid-state is the way to go and ceramics are what should be used, so that’s what we’re using,” explained Niestroj.

Other benefits include flexibility. Because the technology is additive, it’s possible to 3D print batteries of any shape and to fabricate different shapes within a single build.

“For example, if you imagine a big bed one by two meters in area, you could print thousands of AA batteries in just a few hours,” Niestroj said.“The amazing advantage, of course, is you can print any geometry. With the same printer, you could print cylindrical cells one hour, rectangular the next hour, and any other shape the hour after that.”

Though Niestroj did not speak to this quality in particular, it’s worth noting that, with binder jetting technology, it’s possible to incorporate additives into the printing process. This can be achieved using the actual inkjet head, which is used to deposit both a liquid binder and CMYK ink in the case of gypsum printing. It can also be accomplished during a subsequent infiltration process, once the part is printed. For metals, bronze is often used to infiltrate a part, whereas gypsum parts may be immersed in an acrylate for further strengthening.

Forming KeraCel

According to Niestroj, KeraCel was bootstrapped by its founders, seasoned executives of the semiconductor industry, with their own money. The team has over 15 years of experience in the technologies being used and developed at the startup, including AM, ceramics and productization of manufacturing processes.

For his part, Niestroj joined KeraCel just two months ago, shortly after spending more than 20 years with Mercedes-Benz. Trained as a nuclear physicist, he has spent much of his career working on research and development for EV development with the German automaker. This included running a joint venture between Mercedes and Bosch devoted to developing electric motors for EVs.

Niestroj went on to become the CEO of Mercedes-Benz Research and Development in North America, where he oversaw everything related to the continent’s passenger car development, also including vehicle testing, the battery lab and battery monitoring technologies. In total, Niestroj has spent 10 years in electric vehicle technology research and development.

“I joined KeraCel because the battery and technology they have is so impressive,” Niestroj said. “I have seen so many battery claims not come true over the last 15 years. So many EV companies have struggled and vanished, but when I saw this KeraCel technology, I got really excited. It’s such a different way of doing a battery, has so much flexibility and such a cost and energy advantage that I said, ‘Fine. I’m going to join their company,’ and now I’m the COO at KeraCel.”

Scaling up for Production

So far, KeraCel claims to have been able to 3D print batteries on a smaller scale, but the firm believes that it is more than feasible to mass manufacture batteries using its technology.

“We have actually proven that we can print these batteries with thin layers. Of course, it is a step-by-step process, but that’s what we’re doing and progressing very fast. Over the course of three years, we have batteries that are cycling—charging and discharging in a cycling device,” Niestroj said. “We’re a startup and we’re still developing this technology, but [mass manufacturing] is the target we’ve set for ourselves.”

He went on to describe how the technology has been validated on the product and process development side, but also based on existing science and simulation.“There are simulation tools, in which you enter values for material types, the thickness of the layers, and the electric metrics of the battery—like internal resistance and cathode loading. If you put in our values, we see that our technology works,” Niestroj explained. “The science proves that it is possible and when you talk to big battery companies, the answer typically is,‘This is all nice, but you have to prove that you can actually manufacture it.’ That is the bigger challenge. So far, we have proven every milestone of actually manufacturing it, like the first 3D-printed complete battery structure in the middle of this year.”

If the team is able to 3D print batteries using a small binder jetting system, as they say they can, it’s definitely not impossible to imagine the use of a large-scale machine. For instance, a printer like the massive VX4000 system from voxeljet could be used to print batteries within a build chamber of 4m x 2m x 1m.

Bringing 3D-Printed Batteries to Market

After almost three years of R&D, KeraCel came out of stealth mode with the announcement that it partnered with Japanese auto parts manufacturer Musashi Seimitsu Industry Co. Musashi Seimitsu has invested in the Silicon Valley startup and, together, the two will work to advance KeraCel’s battery printing technology to make it capable of mass production.

A motorcycle part from Musashi Seimitsu. (Image courtesy of Musashi Seimitsu.)
A motorcycle part from Musashi Seimitsu. (Image courtesy of Musashi Seimitsu.)

Founded in 1938, Musashi Seimitsu is a publicly traded Japanese company that produces motor, suspension and steering parts for cars, motorcycles and ATVs. With around 18 subsidiaries covering North America, Europe, Asia and South America, the company makes everything from ball joints and gears to camshafts.

Niestroj was not able to disclose too much about the relationship between the two businesses, but if you look at the future of the electric motorcycles globally, it’s possible to imagine a boom for the type of low-cost, solid-state electric batteries to be 3D printed by KeraCel. This is particularly true in the warmer climates (which will only become hotter as the climate emergency worsens) because ceramic batteries can withstand higher temperatures than the lithium-ion variety, which use liquid or gel electrolytes and don’t operate as well in higher temperatures.

Of course, as the climate emergency progresses, there will be issues related to material supplies because typical metals found in lithium-ion batteries, such as cobalt and, eventually, lithium itself, are not infinite. The authors of Achieving the Paris Climate Agreement Goals estimate that there will not be enough lithium or cobalt to meet the production required for renewable technology demand.

The authors wrote: “The cumulative demand for cobalt from renewable energy and transport exceeds the current reserves in all scenarios, and for lithium, the cumulative demand is exceeded in all scenarios, except the ‘potential recycling scenario.’”

Niestroj noted that, even though KeraCel’s technology can use half the materials necessary, dwindling metal supplies will be an issue for all battery makers. However, what he sees as an advantage is the fact that his firm’s process can use any cathode material and is not limited to metals like cobalt.

Moreover, if battery recycling does become the go-to process for increasing supplies, Niestroj believes that KeraCel’s feedstock will be more easily obtained, given that it’s powder based. Once the batteries are crushed up, they will be returned to that powder state.

Such ideas are likely further down the road for KeraCel, which is still in the process of developing its technology for production in the first place. For this reason, as KeraCel continues its work with Musashi Seimitsu, the company continues to look for additional investors for Series A fundraising.

To learn more about the company, visit the KeraCel website.

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