Improvement of cycling performance in bismuth fluoride electrodes by controlling electrolyte composition in fluoride shuttle batteries
- 381 Downloads
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 0.45 mol dm−3 cesium fluoride (CsF) and 0.5 mol dm−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.
KeywordsFluoride shuttle battery Bismuth fluoride Anion acceptor Cycle performance XPS
This work was supported by the Research and Development Initiative for Scientific Innovation of New Generation Batteries (RISING) and Research and Development Initiative for Scientific Innovation of New Generation Batteries 2 (RISING2) projects from the New Energy and Industrial Technology Development Organization (NEDO), Japan. The authors thank Ms. Kiyomi Ishizawa, Ms. Ryoko Masuda, and Ms. Hisayo Ikeda for their experimental support.
- 26.Konishi H, Minato T, Abe T, Ogumi Z (2017) Cycling fading mechanism for a bismuth fluoride electrode in a lithium-ion battery. Chem Sel 2:3504–3510Google Scholar
- 27.Konishi H, Minato T, Abe T, Ogumi Z (2017) Electrochemical reaction mechanism for Bi1−xBaxF3−x (x = 0, 0.1, 0.2, and 0.4) electrodes in lithium-ion batteries. Chem Sel 2:6399–6406Google Scholar