Modified coin cells to evaluate the electrochemical properties of solid-state fluoride-ion batteries at 150 °C

Abstract

In the scope of developing new chemistries for electrochemical energy systems, rechargeable solid-state fluoride-ion batteries are attractive devices owing to their high theoretical energy density. State of the art of fluoride ion conductors require the use of high temperature electrochemical cells to overcome the low ionic conductivity of the electrolyte at room temperature. In this work, we modify a coin cell to evaluate the electrochemical properties of fluoride-ion batteries at elevated temperature, over long periods of time and outside a glovebox. The coin cell is covered by a high-temperature epoxy resin that enables efficient sealing and therefore protection against air atmosphere at 150°C. The suitability of the setup is confirmed by electrochemical investigation performed on a symmetrical cell assembled with composite electrodes made of Bi and BiF3. Notably, a reversible capacity of around 190mAh/g after 3 cycles is reached with the modified coin cell setup.