NASA’s solid-state batteries kept working at minus 80 degrees Celsius

NASA researchers report that small prototype cells for a solid-state lithium battery kept working at minus 80 degrees Celsius (minus 112 degrees Fahrenheit) in thermal vacuum tests at NASA’s Langley Research Center in Hampton, Virginia, with slightly reduced performance at that extreme. Yi Lin, the SPEARS testing and research lead at Langley, said the team had proved for the first time that the cells can operate down to that temperature. The target is the Moon’s South Pole, where nighttime temperatures can fall to about minus 328 degrees Fahrenheit (minus 200 degrees Celsius).

SPEARS stands for Solid Power for Extreme Environment Adaptability and Resilience in Space, and NASA is developing it to power lunar operations during the Artemis campaign. The project is led from NASA’s Glenn Research Center in Cleveland by principal investigator Donald Dornbusch and began in 2026.

Liquid electrolytes freeze, overheat and boil off

NASA’s project report explains the problem SPEARS is meant to solve. Standard lithium-ion batteries rely on a liquid electrolyte, and that liquid has three weaknesses in space: it can freeze during the Moon’s cold nights, potentially damaging the battery, it stops working when it gets too hot during the lunar day, and it evaporates in vacuum. Dornbusch said that batteries are a need on the Moon just as they are on Earth, which is the premise of an Artemis-era effort to support a sustained human presence there.

SPEARS replaces the liquid with a solid electrolyte, the central design choice of the project. Because solids do not freeze the way liquids do, the cells can withstand extreme cold, and they can also tolerate heat and vacuum.

Test results from 176 degrees Fahrenheit down to minus 112

Photos published with the report show the prototypes are small coin-cell batteries, and a thermal vacuum team member, support engineer Nike Lin, is pictured holding one. The distinction between surviving and operating matters for reading the minus 80 figure. In thermal vacuum testing at Langley, the prototype cells operated well up to 176 degrees Fahrenheit (80 degrees Celsius) and down to minus 76 degrees Fahrenheit (minus 60 degrees Celsius). Between minus 60 and minus 80 degrees Celsius they still worked but with slightly reduced performance, so the minus 80 figure is the outer edge of the cells’ operating range rather than a point of full output.

A separate result covers survival. The batteries withstood swings from 212 degrees Fahrenheit (100 degrees Celsius) down to minus 274 degrees Fahrenheit (minus 170 degrees Celsius) without damage. They cannot operate at minus 274 degrees, so small heaters would warm them to operating temperature when needed, which means they do not have to be kept warm constantly. The arrangement trades a small amount of heater power for the ability to leave the cells exposed to cold that would otherwise damage a liquid-electrolyte battery against South Pole nights that can reach about minus 328 degrees Fahrenheit, where the cells would otherwise sit far below their operating range. Lin said the team is confident that performance can improve and that the operating range may expand in the coming years.

The research behind SPEARS has a published trail. Lin and Ji Su, the polymer materials scientist who serves as task lead at Langley, appear alongside Dornbusch among the authors of a 2026 Space Power Workshop presentation on materials challenges for solid-state batteries in aerospace, also logged in NASA’s technical reports server. That presentation reports on the earlier SABERS program of lithium-sulfur cells rather than on SPEARS test data, which the NASA report is the source for.

Lunar drills and rovers, and what reaches phones and cars

NASA says a solid-state design could reduce the need for heavy thermal management systems in spacecraft and habitats, which could mean lighter designs, lower costs and longer missions. The agency lists possible lunar uses: drills operating in shadowed craters, rovers, emergency power packs for astronauts and long-duration scientific instruments.

The technology could also come back to Earth. SPEARS grew out of an earlier Lin and Dornbusch project focused on aeronautics, and Lin explained that batteries can be tuned for energy, power or durability by changing electrode materials. Ji Su listed automobiles, cell phones, communication devices and drones as possible markets. NASA already offers a related lithium-sulfur package for licensing, the SABERS 2.0 portfolio from Glenn and Langley, which it says has components at technology readiness level 4 and patents pending.

The project is funded through the Advanced Research and Technology division of NASA’s Research and Technology Mission Directorate. Its first stage focuses on technology development and may later shift toward commercial collaboration, while NASA’s Ames Research Center is developing flight hardware such as test boards and electronics to prepare the batteries for spaceflight. No flight date is given, so the cells remain laboratory prototypes whose limit, by Lin’s account, is not yet settled.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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