Synthesis and electrochemical performances of cathode material Fe0.5Co0.5S2 for thermal batteries by a facile molten salt method

Fe0.5Co0.5S2 combined the advantages of FeS2 and CoS2 has been considered as one of the most promising cathode materials for thermal batteries. However, traditional methods are inefficient or difficult to prepare high-purity Fe0.5Co0.5S2. Here, a facile salt method was used to successfully prepare the cathode material Fe0.5Co0.5S2 for thermal batteries. The Fe0.5Co0.5S2 exhibited a discharge specific capacity of 705 mAh g(-1) with a cut-off voltage of 1.2 V, which was 27.5% higher than FeS2 and 14.8% higher than CoS2. Simultaneously, its discharge pulses could reach 19, while there were only 16 pulses for FeS2 and CoS2. Furthermore, the Fe0.5Co0.5S2 also showed good air stability. After being stored at 100% relative humidity and 30 degrees C for a week, no visible impurities or significant reduction in discharge pulses were found. This work provided a simple, efficient, and low-cost synthesis method that would well support the preparation of Fe0.5Co0.5S2 for thermal batteries.