LAUSR

Abstract Porous ceramic separator materials have been used to enhance the performance of thermal batteries but they are not sufficiently effective. In this study, we developed a porous ceramic fiber separator substrate using Mullite fiber (a kind of ceramic fiber) employing the wet-laid technology. The substrate was modified using magnesium acetate precursors to obtain a porous, flexible, strong ceramic fiber separator (CFS) containing Nano-MgO particles. Although the diameter of CFS exceeded 11.3 cm, it was relatively thin (approximately 0.3 mm). Application of CFS clearly improved the electrochemical performance of the conventional Li-B/LiF-LiCl-LiBr/FeS2 electrochemical system. Li-B/LiF-LiCl-LiBr/FeS2 electrochemical system fitted with CFS increases the specific capacity of the battery by 24% and yields a polarization resistance of 0.011 Ω even with a high current pulse density of 5000 mA·cm−2. The findings of this study demonstrate that CFS can effectively improve performance of current thermal battery electrochemical systems.