Material Insights · Understanding the Material World

High-temperature batteries

Molten-electrode batteries that run hot.

Storage · Electrochemical · No. 75

  • Storage
  • Duration: Hours
Storage · Electrochemical · Foundation · Energy

These batteries only work when their sodium is molten at about 300 C, and they have run grids for two decades.

Chart: Illustration: High-temperature batteries

Where it comes from

Chart: Map of where it comes from

Common sodium, sulphur and alumina are sealed in steel cells that run at 290 to 360 C, needing no lithium, cobalt or air conditioning.

Three things to know
  1. Molten sodium passes through a solid ceramic to react with molten sulphur, so the cells need no lithium or cobalt.
  2. A 2 MW sodium-sulphur battery caught fire at Tsukuba in 2011, halting operations until June 2012.
  3. NGK, the main maker, decided on 31 Oct 2025 to stop making and selling sodium-sulphur batteries, at a charge of about JPY 18 billion.
The journey
  1. 1 Cheap materialsSodium, sulphur, alumina, salt, some nickel
  2. 2 Ceramic tubeBeta-alumina lets only sodium ions through
  3. 3 Heated cellKept near 300 C for life
  4. 4 Container1,450 kWh in a 21 t box
  5. 5 Grid serviceSix-hour shifting, backup, peak shaving
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