Moon batteries that don't mind the cold (mostly)
The full reading behind my Short: NASA is testing solid-state batteries for the lunar night. Promising early results, but not a finished battery yet.
The short version
NASA is developing SPEARS, solid-state batteries meant to cope with the extreme temperatures on the Moon [1]. In thermal vacuum tests at NASA Langley, prototype cells worked well down to −60°C and, with slightly reduced performance, to −80°C. They also operated well up to 80°C, and after exposure from 100°C down to −170°C they were not damaged [1].
Liquid vs solid
Conventional lithium-ion batteries rely on a liquid electrolyte. In the lunar night it can freeze; in daytime heat it can stop working; in a vacuum it can evaporate [1]. SPEARS replaces the liquid with a solid ceramic or polymer material [1].
Researcher Yi Lin: "We proved for the first time that these cells can work down to minus 80 degrees Celsius" [1].
Watch the Short
About this page
The Short uses NASA public-domain photos (NASA/Ryan Hill at Langley, the LRO south pole mosaic and Apollo 11) plus my own simple animations (thermometer, battery cells, heater), which are illustrations and not to scale. This page is general science news.
Why it matters, and what it isn't yet
- Not finished. At −170°C the cells don't run; small heaters are still needed to warm them back up [1].
- Less heating. Because they wouldn't need constant heating, this could allow lighter, cheaper designs for spacecraft and habitats [1].
- Early stage. This is early lab work that began in 2026. The project is led at NASA Glenn, and flight hardware is being developed at NASA Ames [1].
Full narration (transcript)
Batteries hate the cold, and nights at the Moon's south pole can fall to 200 below zero, Celsius. To cope, NASA engineers are developing a new solid-state battery for the Moon. Lithium-ion batteries use a liquid that freezes at night, fails in daytime heat, and evaporates in a vacuum. Their design swaps that liquid for a solid, ceramic or polymer material. In thermal vacuum tests at NASA Langley, prototype cells worked well at 60 below zero, Celsius, and with slightly reduced performance at 80 below. After exposure from 100 Celsius down to 170 below zero, the batteries were not damaged. But this is not a finished lunar night battery yet. At 170 below zero they don't run, and small heaters are still needed to warm them back up. Needing no constant heating could make missions and habitats lighter and cheaper. It's early lab work, begun this year, with flight hardware being developed at NASA Ames.
Sources
- [1] NASA Langley. "NASA Develops Batteries to Power Humanity's Return to Moon." nasa.gov
- [2] Images: NASA/Ryan Hill (public domain); NASA/LRO South Pole mosaic (public domain); NASA Apollo 11 (public domain).
Credits
Images: NASA (public domain). Animations: my own illustrations. Not endorsed by NASA.