A Next-gen Sodium Grid Battery Outta ARPA-E

Japan is the official leader when it comes to using its own sodium sulfur (NAS) batteries for energy storage on the power grid. There are close to 270 MW of NAS batteries on the grid in Japan and the country’s NGK Insulators is a NAS battery market king, according to the Electric Storage Association. That’s compared to just 9 MW of NAS batteries that U.S. utilities have deployed. But a project from the Pacific Northwest National Laboratory and battery and electrochemical company Eagle Picher Technologies plan to use an ARPA-E grant to develop a next-generation sodium battery here in the U.S. for the power grid.
David Lucero, director of alternative energy storage for EaglePicher Technologies, and Gary Yang, chief scientist of energy storage at the Pacific Northwest National Laboratory, told me in a phone interview on Tuesday that their planar-shaped sodium beta-battery design will be less expensive and will have a 30 percent higher energy density than standard NAS batteries. Eventually the battery could cost $200 per kWh, said Lucero, compared to the current costs of NAS batteries that he said can range closer to $500-$600 per kWh.

What’s the innovation? Lucero and Yang say it’s largely in the planar-shaped design of the battery — most sodium batteries are tubular in shape — which makes the team’s battery able to be stacked for use in projects at large and small scale, cheaper and more reliably than other battery technologies. Lithium-ion batteries can’t be stacked and deliver the same level of reliability, explained Yang. The team is also investigating new types of materials that could help cut the price and raise the energy density.
The development stage of the sodium battery project will cost around $9 million — $7 million from the ARPA-E program and $1.8 million from Eagle Picher. The three-year project has three stages of development, and Lucero said that the group has to meet “go or no-go” milestones all along the way. Bringing a battery like this into production will take more funds, and scaling it into mass production will take many more hundreds of millions of dollars — as recently bankrupted battery startups Firefly Energy and Imara know all too well. (See How EV Battery Startups Can Cross the Valley of Death on GigaOM Pro, subscription required).
The team’s battery is also very much in the proof-of-concept stage at this point, says Yang. The whole point of the ARPA-E program is to fund high-risk, but potentially game-changing, technology, and it’s far from a sure bet that the team’s battery will be able to reach that low-cost goal. One indicator that it will be difficult: Lucero tells us that Eagle Picher started working on the technology 15 years ago for space satellite systems, which can be higher in price than other battery markets. But not foreseeing the rise of the grid storage market, Eagle Picher shut the project down as the market stalled. Now that the project has been revitalized, the team has high hopes that three years and a research partnership between a national lab and an experienced battery manufacturer will give the technology the kick-start it needs.