NASA researchers developing solid-state batteries for future lunar missions have successfully tested prototype cells that survived extreme cold down to minus 274 degrees Fahrenheit. The SPEARS project aims to replace vulnerable liquid electrolytes with ceramic or polymer materials to withstand the brutal environment of the Moon’s South Pole.
Future Artemis campaigns on the Moon will demand power sources capable of surviving some of the most unforgiving thermal extremes in the solar system. While standard lithium-ion batteries rely on liquid electrolytes that can freeze, evaporate in a vacuum, or fail under heavy heat, space agency engineers are turning to solid-state alternatives to power future lunar operations.
Thermal Vacuum Testing at NASA Langley
Researchers put small prototype cells through rigorous thermal vacuum testing at NASA’s Langley Research Center in Hampton, Virginia. The testing pushed the solid-state batteries through dramatic temperature swings, exposing them to highs of 212 degrees Fahrenheit and lows plummeting to minus 274 degrees Fahrenheit.
While the batteries did not sustain physical damage after exposure to that deep cold, survival does not equal active operation. Daytime lunar temperatures reach about 212 degrees Fahrenheit, whereas nighttime lows at the southern pole plunge to a biting minus 328 degrees Fahrenheit. The prototype cells operated well between minus 76 degrees Fahrenheit and 176 degrees Fahrenheit, with reduced performance down to minus 112 degrees Fahrenheit.
We proved for the first time that these cells can work down to minus 80 degrees Celsius.
Yi Lin, SPEARS testing and research lead at NASA Langley
NASA Centers Collaborate on the SPEARS Initiative
Led by the agency’s Glenn Research Center in Cleveland, the project is officially named Solid Power for Extreme Environment Adaptability and Resilience in Space. Additional materials development and testing occur at Langley, while the Ames Research Center in California develops test boards and electronics to prepare the hardware for future spaceflight testing. Donald Dornbusch serves as the principal investigator for SPEARS at Glenn Research Center, overseeing the initiative.
We will need them on the Moon, too, and these batteries will be required to operate reliably and safely in this harsh environment. That’s why we’re working on this technology.
Donald Dornbusch, principal investigator for SPEARS at NASA’s Glenn Research Center
The batteries substitute conventional liquid electrolytes with a solid ceramic- or polymer-based material. This redesign removes the fire hazards linked to flammable liquids and reduces the need for heavy thermal management equipment. Rather than running continuous heaters throughout the freezing lunar night, spacecraft and rovers could use small heaters to bring the batteries back to operating temperature when power is required.
Prototypes Face Hurdles Before Space Deployment
Despite the successful cold-survival tests, the project still faces significant hurdles before deployment. The prototype cells remain small laboratory units and have not yet been demonstrated in space. NASA has not published energy density figures, cycle life data, or an official flight timeline for the hardware, leaving a roughly 120-degree gap between the operational limit and the actual chill of the lunar night.
Solid-state development is also drawing private competition. Alternative solid-state systems like Solidion’s Gen-ECB battery already operate across a similar thermal range and have undergone testing for 500 cycles, while commercial providers compete for infrastructure contracts through NASA’s NextSTEP-3 program.
