am9b09551_si_001.pdf (1.13 MB)
Download fileEffects of Concentrated Salt and Resting Protocol on Solid Electrolyte Interface Formation for Improved Cycle Stability of Anode-Free Lithium Metal Batteries
journal contribution
posted on 2019-08-23, 14:45 authored by Tamene
Tadesse Beyene, Bikila Alemu Jote, Zewdu Tadesse Wondimkun, Bizualem Wakuma Olbassa, Chen-Jui Huang, Balamurugan Thirumalraj, Chia-Hsin Wang, Wei-Nien Su, Hongjie Dai, Bing-Joe HwangThe combined effect
of concentrated electrolyte and cycling protocol
on the cyclic performance of the anode-free battery (AFB) is evaluated
systematically. In situ deposition of Li in the AFB configuration
in the presence of a concentrated electrolyte containing fluorine-donating
salt and resting the deposit enables the formation of stable and uniform
SEI. The SEI intercepts the undesirable side reaction between the
deposit and solvent in the electrolyte and reduces electrolyte and
Li consumption during cycling. The synergy between the laboratory-prepared
concentrated 3 M LiFSI in the ester-based electrolyte and our resting
protocol significantly enhanced cyclic performances of AFBs in comparison
to the commercial carbonate-based dilute electrolyte, 1 M LiPF6. Benefitting from the combined effect, Cu∥LiFePO4 cells delivered excellent cyclic performance at 0.5 mA/cm2 with an average CE of up to 98.78%, retaining a reasonable
discharge capacity after 100 cycles. Furthermore, the AFB can also
be cycled at a high rate up to 1.0 mA/cm2 with a high average
CE and retaining the encouraging discharge capacity after 100 cycles.
The fast cycling and stable performance of these cells are attributed
to the formation of robust, flexible, and tough F-rich conductive
SEI on the surface of the in situ-deposited Li by benefiting from
the combined effect of the resting protocol and the concentrated electrolyte.
A condescending understanding of the mechanism of SEI formation and
material choice could facilitate the development of AFBs as future
advanced energy storage devices.