SPEARS Batteries Survive Extreme Temperature Exposure for Lunar Use

SPEARS solid-state batteries designed for space underwent thermal vacuum testing at NASA's Langley Research Center in Hampton, Virginia. The batteries did not sustain damage after extreme temperature exposure and can survive extreme low temperatures.

SPEARS stands for Solid Power for Extreme Environment Adaptability and Resilience in Space. The effort is led by NASA's Glenn Research Center, with Donald Dornbusch as principal investigator for SPEARS at NASA's Glenn Research Center.

Traditional lithium-ion batteries rely on liquid electrolytes. A liquid electrolyte would freeze at the Moon's nighttime temperatures and evaporates in the vacuum of space.

SPEARS batteries use a solid ceramic- or polymer-based electrolyte and could operate in heat and extreme cold. Their specified range is 212 to -274 Fahrenheit, and they need to remain reliable through lunar day-night temperature swings.

Small prototype battery cells were tested at 176, -76 and -112 Fahrenheit. SPEARS cells also have a milestone at -80 Celsius.

The batteries do not sustain damage after extreme temperature exposure and can survive extreme low temperatures. They use small heaters to regain working temperature and need only be warmed to operational temperature, not kept warm.

For future lunar operations, the battery must work immediately when warmed up without posing a fire hazard. The batteries could reduce heavy thermal management needs.

Applications include payloads such as drills, rovers and emergency power packs, and the batteries could power long-duration scientific instruments. Their chemistry is tunable using different electrode materials.

Conventional liquid-electrolyte batteries face freezing at the Moon's nighttime temperatures and evaporation in space vacuum, while SPEARS can survive extreme low temperatures and could reduce heavy thermal management needs. The batteries could power payloads including drills, rovers, emergency power packs and long-duration scientific instruments, and could power a sustained lunar presence through the Artemis campaign.