We have developed a fluoride shuttle battery (FSB) which is a promising candidate for the next-generation high-energy-density secondary batteries. Using the bis [2-(2-methoxyethoxy) ethyl] ether (tetraglyme: G4) solvent containing 0.45moldm(-3) cesium fluoride (CsF) and 0.5moldm(-3) fluorobis (2,4,6-trimethylphenyl) borane (FBTMPhB) as an electrolyte for FSB, we have successfully conducted the discharge (BiF3+3e(-) Bi+3F(-)) and charge (Bi+3F(-) BiF3+3e(-)) reactions for a BiF3 electrode; however, the discharge and charge capacities significantly decreased during cycling. Atomic absorption spectrometry results indicated that, in addition to the formation of BiF3, dissolution of Bi (Bi Bi3++3e(-)) occurred during the charge process. The dissolution of Bi indicated that the active material was lost from the electrode, which decreased the capacity during cycling. An increased CsF/FBTMPhB ratio in the electrolyte was found to suppress the dissolution of Bi during the charge process and, therefore, improve the cycling performance. [GRAPHICS] .