jz7b02312_si_002.pdf (1.21 MB)
Anion-Dependent Potential Precycling Effects on Lithium Deposition/Dissolution Reaction Studied by an Electrochemical Quartz Crystal Microbalance
journal contribution
posted on 2017-10-05, 00:00 authored by Kumar
Sai Smaran, Sae Shibata, Asami Omachi, Ayano Ohama, Eika Tomizawa, Toshihiro KondoThe electrochemical
quartz crystal microbalance technique was employed
to study the initial stage of the electrodeposition and dissolution
of lithium utilizing three kinds of electrolyte solutions such as
LiPF6, LiTFSI, or LiFSI in tetraglyme. The native-SEI (solid–electrolyte
interphase) formed by a potential prescan before lithium deposition/dissolution
in all three solutions. Simultaneous additional SEI (add-SEI) deposition
and its dissolution with lithium deposition and dissolution, respectively,
were observed in LiPF6 and LiTFSI. Conversely, the add-SEI
dissolution with lithium deposition and its deposition with lithium
dissolution were observed in LiFSI. Additional potential precycling
resulted in the accumulation of a “pre-SEI” layer over
the native-SEI layer in all of the solutions. With the pre-SEI, only
lithium deposition/dissolution were significantly observed in LiTFSI
and LiFSI. On the basis of the potential dependences of the mass and
resistance changes, the anion-dependent effects of such a pre-SEI
layer presence/absence on the lithium deposition/dissolution processes
were discussed.