Investigating SEI Formation on Lithium Metal Anodes

Thursday, 1 June 2017: 16:12
Grand Salon C - Section 13 (Hilton New Orleans Riverside)
S. Jurng, Z. L. Brown, and B. L. Lucht (University of Rhode Island)
The Li plating/stripping performance of LiFePO4/Cu cells has been investigated for carbonate solutions of three different lithium salts, LiPF6, LiBF4 or LiBOB. The coulombic efficiencies of these cells are higher in the early cycles, but drops gradually during cycling. The capacity retention and efficiency of the cells is best with LiBOB followed by LiBF4 while LiPF6 provides the poorest performance. The differences are likely due to changes to the solid electrolyte interphase (SEI) on the surface of the lithium metal electrodes. Ex-situ analysis of the electrodes has been conducted via a combination of XPS and FT-IR to develop a better understanding of the role of the SEI in cycling performance.