10.1021/acsenergylett.7b00619.s001
Alexander Schiele
Alexander
Schiele
Ben Breitung
Ben
Breitung
Toru Hatsukade
Toru
Hatsukade
Balázs B. Berkes
Balázs B.
Berkes
Pascal Hartmann
Pascal
Hartmann
Jürgen Janek
Jürgen
Janek
Torsten Brezesinski
Torsten
Brezesinski
The Critical Role of Fluoroethylene Carbonate in the
Gassing of Silicon Anodes for Lithium-Ion Batteries
American Chemical Society
2017
next-generation lithium-ion batteries
electrochemical mass spectrometry
electrolyte
cycling
Li x Si alloys
CO
FEC
H 2
C 2 H 4
Si vs Li
2017-08-17 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/The_Critical_Role_of_Fluoroethylene_Carbonate_in_the_Gassing_of_Silicon_Anodes_for_Lithium-Ion_Batteries/5378095
The
use of functionalized electrolytes is effective in mitigating
the poor cycling stability of silicon (Si), which has long hindered
the implementation of this promising high-capacity anode material
in next-generation lithium-ion batteries. In this Letter, we present
a comparative study of gaseous byproducts formed by decomposition
of fluoroethylene carbonate (FEC)-containing and FEC-free electrolytes
using differential electrochemical mass spectrometry and infrared
spectroscopy, combined with long-term cycling data of half-cells (Si
vs Li). The evolving gaseous species depend strongly on the type of
electrolyte; the main products for the FEC-based electrolyte are H<sub>2</sub> and CO<sub>2</sub>, while the FEC-free electrolyte shows
predominantly H<sub>2</sub>, C<sub>2</sub>H<sub>4</sub>, and CO. The
characteristic shape of the evolution patterns suggests different
reactivities of the various Li<sub><i>x</i></sub>Si alloys,
depending on the cell potential. The data acquired for long-term cycling
confirm the benefit of using FEC as cosolvent in the electrolyte.