Unleash mass production of solid-state batteries

Battery production is a hot topic today, as does the increase in this production. Sakuu Corp., formerly KeraCel Inc., claims to have cracked the secret of mass-produced solid-state batteries (SSBs). The solution is additive manufacturing (AM). The San Jose, Calif. company is gearing up to manufacture its own ceramic and pure lithium batteries and sell its AM technology later this year.

If true, the company has beaten many other companies, including Toyota Motor Corp., in its quest to be the first to manufacture a scalable SSB. The technology is desirable because of its advantages over lithium-ion batteries, which were commercialized in the early 1990s. SSBs can withstand higher temperatures, charge faster, and withstand more charge/discharge cycles before depleting. degrade. They are also more energy dense, which helps reduce bulk and weight. The elimination of flammable liquid electrolytes means that safety electronics can also be eliminated from the battery. SSBs have been used for years in small devices like pacemakers, wearables, and radio frequency identification.

Properties such as higher energy density, light weight, faster charging and increased safety are particularly essential for electric vehicles. In fact, the future of electric vehicles may hinge on the ability to mass-produce SSBs, some say. “A big leap is needed to increase the distances these batteries can power cars,” wrote Emily Pickrell, University of Houston (UH) Energy Scholar, on the UH Energy Fellows Forbes Blog in June. “In practical terms, this has limited the distance that electric cars can travel before needing to be recharged.”

SSBs are so vital to the future of electric vehicles that automakers are investing in battery development companies, according to published reports. BMW and Ford have invested in Solid Power, which set in early 2022 to pilot production of electric vehicle batteries. Volkswagen has invested in QuantumScape, which aims to offer commercial SSBs by 2024. Toyota plans to use its first SSB for an EV by 2030. Sakuu is teaming up with Honda affiliate Musashi Seimitsu, a Japanese supplier of auto parts to major OEMs, according to a press release. Release.

Robert Bagheri, Founder, CEO and President of Sakuu, said in an interview that his company has succeeded over competitors because 3D printing is the only way to make a battery’s ceramic layer thin enough for optimal performance. His company’s technology uses powder-based binder jetting to produce batteries in a green state. The parts are then finished in a sintering furnace.

3D printing is the only way

“They (the competitors) are trying to build this the old-fashioned way, the roll-to-roll method, but the ceramic is very fragile,” Bagheri said. “It cannot operate in a roll-to-roll environment. It should be very thin, like less than 50 µm thick or less than 30 µm thick. The only way to do this is to use 3D printing. This is why no SSB company has yet been able to scale.

Sakuu printers can print different materials in a single layer, which Bagheri said is a first. “We can bring metal, ceramic (and) polymer in the same layer, with the same tooling,” he said. “It has a lot of built-in intelligence that allows us to do online QA at every layer.”

He estimates that a battery cell takes 30 seconds or less to print, and that the 8,000 cells of a 75kW battery would take a maximum of six hours. Bagheri, an electrical engineer with experience in the semiconductor industry, said his biggest run in mid-July was 250 cells in a month on Sakuu’s development machine. It had yet to run a production run on the Sakuu 1000, the model expected to be available in Q4 2021.

Beyond energy storage, Sakuu says its multi-material, single-layer printing technology opens 3D printing to manufacturing sensors and electric motors for many applications.