A novel thermal battery based on fluoride ion conduction

Abstract

Fluoride ion battery was expected to become a new generation of energy storage system because of its high theoretical energy density. However, at room temperature, the ratio property of fluoride ion batteries was poor. Consequently, we conducted an investigation into the potential application of this technology in high-temperature primary discharge. A novel thermal battery based on fluoride ion conduction was reported, which can discharge with a large current at high temperature. Assemblying NiF₂|NaF-KF-CsF@MgO|La thermal battery, the ionic conductivity of NaF-KF-CsF electrolyte run up to 2.47 × 10^-1 S cm^-1 at 550°C. The battery has much higher ratio property than reported fluoride ion battery systems and the specific capacity can reach 60 mAh g^-1(@1.35 V, 200 mA cm^-2). Although the results are promising, they are not yet sufficient to meet the practical application scenarios of thermal batteries. Hence, this was a preliminary attempt to apply fluorine ion conduction to the field of thermal battery.