Thermal Battery Technologies and Electrochemical Performance

Thermal batteries are high-temperature, primary electrochemical devices that employ an internal heat source to melt a solid electrolyte into a conductive molten salt. Once activated, they deliver rapid power pulses, high specific energy and long shelf life, making them indispensable in defence, aerospace and emergency power-backup applications. Key components include a lithium or sodium alloy anode, a molten chloride or fluoride salt electrolyte and a conversion-type cathode, typically composed of metal sulfides, chlorides or fluorides. The electrochemical performance of these systems depends on ionic conductivity of the electrolyte, electronic conductivity of the electrode materials, thermal stability and reaction kinetics at elevated temperatures (typically 350–600 °C). Recent advances focus on tailoring electrode architectures—such as core–shell composites and conductive networks—and on designing low-volatility binders to enhance mechanical integrity, reduce polarization and improve material utilisation. In parallel, in-situ characterisation has begun to unravel high-temperature reaction mechanisms, guiding the development of next-generation thermal batteries with improved energy-power balance and enhanced reliability under thermal shock.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Thermal Battery Technologies and Electrochemical Performance publication trend

The graph below shows the total number of articles in thermal battery technologies and electrochemical performance across all publications each year (not limited to Nature Index journals).

Technical terms

Molten salt electrolyte: A mixture of inorganic salts that becomes liquid at elevated temperature, providing ionic conduction between electrodes.

Conversion-type battery: A system in which energy storage relies on a reversible chemical conversion reaction of active materials rather than intercalation.

Specific capacity: The electric charge stored per unit mass of electrode material, typically expressed in milliampere-hours per gram (mAh g⁻¹).

Core–shell structure: A material design in which one functional phase (core) is encapsulated by a second phase (shell) to combine complementary properties such as conductivity and stability.

Galvanostatic discharge: An electrochemical testing protocol in which a constant current is applied to discharge a cell, used to assess capacity and voltage response under controlled load.

References

1. Low‐Volatile Binder Enables Thermal Shock‐Resistant Thin‐Film Cathodes for Thermal Batteries. Energy & Environmental Materials (2023).
2. Scalable Preparation and Improved Discharge Properties of FeS2@CoS2 Cathode Materials for High-Temperature Thermal Battery. Nanomaterials (2022).
3. FeF3/(Acetylene Black and Multi-Walled Carbon Nanotube) Composite for Cathode Active Material of Thermal Battery through Formation of Conductive Network Channels. Nanomaterials (2023).