Al2O3 nanoparticles modified the FeS2 cathode to boost the interface wettability and electrochemical performance for thermal batteries

Abstract

Thermal batteries are widely employed as the primary reserve batteries due to their high energy density and long shelf lifespan. FeS2 is the most studied and promising cathode material of thermal batteries at present because of its abundant stock and superior electrochemical performance. However, the FeS2 cathode is limited by low discharge capacity, big polarization, and security issues during discharge process. Herein, the improved electrochemical performance is achieved by increasing the interface wettability between cathode and electrolyte, in which the FeS2 cathode has modified by Al2O3 (FeS2@Al2O3) nanoparticles. The good wettability of the solid-liquid interface suppresses the overflow of electrolytes, and the discharge capacity of thermal batteries by using FeS2@Al2O3 cathode is 341.3 mAh·g−1, which is higher than that of pure FeS2 cathode (319.7 mAh·g−1). Significantly, this work provides a novel idea for modifying cathode material for comprehensive performance and safe thermal batteries in practical engineering applications.