24M’s semi-solid lithium cells going into production through Kyocera

Early lab-based production for 24M in Cambridge, Mass. Image: 24M.

24M, currently thought to be one of the leaders in developing an advanced form of lithium-ion batteries which promise increased energy density, has struck a deal with Kyocera for initial production of cells for stationary storage applications.

Energy-Storage.news interviewed some of 24M's leadership team in March this year, when the company, spun out of MIT's labs by founder Yet-Ming Chiang, claimed to have exceeded an energy density of 350Wh per kilogramme for semi-solid lithium-ion battery cells.

While admitting that the technology is still at the early stages of its commercialisation journey, 24M said then that it is looking to establish a 100MW pilot production plant by the end of this year.

Kyocera, headquartered in Japan's old capital, Kyoto, and known for its historic production of ceramic goods and latterly high tech products for a range of markets including solar PV, is already an investor in the US start-up. 24M said in a release on Friday that Kyocera is now constructing production facilities for pilot production of cells, aimed at the residential solar-plus-storage market, which is rapidly growing in Kyocera's home country. The pilot production line is in Osaka, in the west of Japan and home city to many of the country's battery big-hitters, including Panasonic and Sanyo Maxcell.

"Kyocera considers the unique 24M SemiSolid approach the emerging standard for lithium-ion battery manufacturing. The ability to cost-effectively manufacture advanced lithium-ion batteries can enable Kyocera to expand residential sales throughout Japan," Kyocera senior executive officer Masahiro Inagaki.

Taking lithium into advanced and long duration territory

In an in-depth interview with this site at the time of that March announcement, 24M's execs including CEO Rick Feldt said that the 'Dual Electrolyte' tech the company has developed could be applied for manufacturing processes for different types of lithium-ion battery, including lithium iron phosphate (LFP) and nickel manganese cobalt (NMC).

Feldt and his colleagues believe that advances such as the development of semi-solid electrolytes (distinctly separate to solid state technology as seen in computer memory storage and processing) can "extend the runway" for lithium batteries, allowing for longer durations of storage with a battery chemistry typically associated with storing energy for up to about four hours in grid-connected applications.

Joe Adiletta, 24M's product manager argued in that interview that he saw flow batteries as being a much longer-term prospect in the market, if at all. Lithium battery makers can lean on the scale and synergies enabled by use of similar devices in electric vehicle and portable electronics markets, an avenue not open to the flow battery industry as it stands.

"As technologies like ours proliferate and as the cost of lithium-ion continues to go down and as the scale continues to go up, flow battery guys are continuing to fight upstream," Adiletta said.

"The issue is that there is no scale to speak of and the only way to get to scale is to have a compelling cost advantage vs lithium-ion. You can see the cost projections for lithium-ion and I don’t think flow is going to be in that ballpark, or just barely in there if at all."

The semi-solid cell production process, in which active materials in electrolytes are mixed together before forming the cell, rather than ‘injecting’ the electrolyte into a slurry creates compositionally distinct catholytes and anolytes, kept apart by an ionically conductive, non-permeable separator. 24M claims the process, which creates electrodes four to five times thicker than in conventional devices, can make substantial cost savings on production and materials - claiming as much as a 50% capital reduction is achievable overall.

"Kyocera is a long-time investor and supportive partner of 24M and we look forward to realizing our shared vision for cost-effective lithium-ion battery manufacturing. Kyocera’s plans to use the 24M SemiSolid platform is validation that our low-capital, cost-effective approach is achievable at scale," 24M CTO and president Naoki Ota said.

24M's 'Dual Electrolyte' technology. Image: 24M

Stay up to date with the latest news, analysis and opinions. Sign up here to the Energy-Storage.news Newsletter.