Advancing Fluoride-Ion Batteries with a Pb-PbF2 Counter Electrode and a Diluted Liquid Electrolyte

Giulia Galatolo; Omar Alshangiti; Camilla Di Mino; Guillaume Matthews; Albert W Xiao; Gregory J Rees; Maximilian Schart; Yvonne A Chart; Lorenz F Olbrich; Mauro Pasta

doi:10.1021/acsenergylett.3c02228

Advancing Fluoride-Ion Batteries with a Pb-PbF₂ Counter Electrode and a Diluted Liquid Electrolyte

ACS Energy Lett. 2023 Dec 8;9(1):85-92. doi: 10.1021/acsenergylett.3c02228. eCollection 2024 Jan 12.

Authors

Giulia Galatolo¹, Omar Alshangiti¹, Camilla Di Mino^{1

2}, Guillaume Matthews^{1

2}, Albert W Xiao¹, Gregory J Rees^{1

2}, Maximilian Schart¹, Yvonne A Chart^{1

2}, Lorenz F Olbrich¹, Mauro Pasta^{1

2}

Affiliations

¹ Department of Materials, University of Oxford, Oxford, OX1 3PH, United Kingdom.
² The Faraday Institution, Harwell Campus, Quad One, Becquerel Avenue, Didcot OX11 0RA, United Kingdom.

Abstract

Fluoride ion batteries (FIB) are a promising post lithium-ion technology thanks to their high theoretical energy densities and Earth-abundant materials. However, the flooded cells commonly used to test liquid electrolyte FIBs severely affect the overall performance and impede comparability across different studies, hindering FIB progress. Here, we report a reliable Pb-PbF₂ counter electrode that enables the use of two-electrode coin cells. To test this setup, we first introduce a liquid electrolyte that combines the advantages of a highly concentrated electrolyte (tetramethylammonium fluoride in methanol) while addressing its transport and high-cost shortcomings by introducing a diluent (propionitrile). We then demonstrate the viability of this system by reporting a BiF₃-Pb-PbF₂ cell with the highest capacity retention to date.