Chinese scientists unlock new era for cathodes in thermal batteries

Chinese scientists from the Institute of Process Engineering at the Chinese Academy of Sciences have made a significant breakthrough in thermal battery technology by developing a novel cathode material that addresses a longstanding performance issue. Thermal batteries, which operate at extremely high temperatures (350–550 °C) using molten salt electrolytes, are critical for applications in military, aerospace, and emergency power systems where conventional batteries fail. However, their cathode materials, particularly transition metal fluorides like CoF₂, suffer from the “shuttle effect,” where active particles dissolve and migrate within the electrolyte, causing capacity loss and structural damage. To overcome this, the research team led by Prof. Wang Song and Zhu Yongping engineered a specialized carbon shell derived from covalent organic frameworks (COFs) around CoF₂ particles. This shell selectively permits beneficial ion transport while preventing harmful dissolution, effectively suppressing the shuttle effect. Their findings, published in Advanced Science, provide a mechanistic foundation for designing next-generation high-energy-density thermal batteries through precise