Xu Yichun, Li Hongliang, Cao Yong, Wang Chao, Cui Yanhua
Institute of Electronic Engineering, China Academy of Engineering Physics Mianyang 621900 P.R.China
RSC Adv. 2025 Mar 25;15(12):9153-9158. doi: 10.1039/d5ra00351b. eCollection 2025 Mar 21.
Transition metal sulphides have been widely studied in the field of thermal batteries, but their low decomposition temperature, low conductivity, and discharge capacity are still pressing issues hampering their practical application. Inspired by the strategy of entropy increase in sodium-ion and lithium-ion batteries, herein, we propose an FeCoNiS cathode material possessing the advantages of electrochemically active elements Fe, Co, and Ni. FeCoNiS exhibited a thermal decomposition temperature of 591 °C, which was significantly higher than that of FeS. Furthermore, the wettability of the LiCl-KCl molten salt on the surface of FeCoNiS was improved and its contact area was 1.1 times that of FeS, providing more active sites for electrochemical reactions and effectively improving the electrochemical performance of the material. Moreover, it exhibited a specific capacity (cutoff voltage ≥1.5 V) of 584 mA h g at 500 °C with a discharge current of 100 mA cm, representing an increase of approximately 96.5% compared to that of CoS. Thus, this work presents a new strategy for the design of high-performance cathode materials for thermal batteries.
过渡金属硫化物在热电池领域已得到广泛研究，但其分解温度低、导电性差和放电容量低仍是阻碍其实际应用的紧迫问题。受钠离子电池和锂离子电池中熵增策略的启发，在此，我们提出了一种具有电化学活性元素铁、钴和镍优点的FeCoNiS正极材料。FeCoNiS的热分解温度为591℃，明显高于FeS的热分解温度。此外，LiCl-KCl熔盐在FeCoNiS表面的润湿性得到改善，其接触面积是FeS的1.1倍，为电化学反应提供了更多活性位点，有效提高了材料的电化学性能。此外，在500℃、放电电流为100 mA cm时，它的比容量（截止电压≥1.5 V）为584 mA h g，与CoS相比增加了约96.5%。因此，这项工作为热电池高性能正极材料的设计提出了一种新策略。
