SEI Layer Formation on Amorphous Si Thin Electrode during Precycling

Abstract

The morphological and compositional changes of the solid electrolyte interphase (SEI) layer formed on the surface of Si thin electrodes during precycling were investigated. At the beginning of charging, the native layer ( SiO2 and silanol) covering the surface of the Si thin electrode is readily destroyed and a new SEI layer is formed by the decomposition of both organic solvents and anions. At this stage, the interfacial resistance decreases to a minimum level. Thereafter, the interfacial resistance increases with charging due to the growth of an SEI layer, which is mainly originated from the decomposition of organic solvents. During the discharging process, an SEI layer was formed mainly by the decomposition of anions.

A hard X-ray photoelectron spectroscopy study on the solid electrolyte interphase of a lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide based electrolyte for Si-electrodes

“…For the most lithiated phase, the shift has been found to be slightly below -2 eV for Si2p electrons. Similar peak shifts can also be observed in earlier PES studies on Si electrodes [7][8][9][10]16]. Observations of changes in peak position due to state of charge for graphite electrodes has also recently been presented and discussed as a result of changes in chemical environment and/or changes in work function [36].…”

“…A lot of work has been done to understand the SEI on graphitic negative electrodes while the field of SEI formation on silicon is still a young area with only a rather small number of publications. [4,[7][8][9][10][11][12][13][14][15][16][17][18][19] Philippe et al have…”

A Carbon Nanotubes-Silicon Nanoparticles Network for High Performance Lithium Rechargeable Battery Anodes

“…The charge (lithiation) plateau at 0.8 V in the first cycle is ascribed to the SEI layer formation. 29,30) The plateau locations during both lithiation and delithiation are also consistent with the aforementioned CV data as well as previously reported values. The Coulombic efficiency in the first cycle turns out to be 63%.…”

Thermal Stability of Lithiated Silicon Anodes with Electrolyte

“…5, the thermal evolution at approximately 140 o C is related to the particle size, the thermal evolution at approximately 140 o C increases with decreasing particle size for fully lithiated Si electrodes. Since the thickness of a solid electrolyte interface (SEI) layer on an Si film anode increases with lithiation 7 and more SEI film is formed in the electrode with a smaller particle size, it is suggested that the thermal evolution at approximately 140 o C is mainly due to the thermal decomposition of the SEI film. The major exothermic peak is significantly reduced and shifted to the lower temperature side as the Si particle size decreases.…”