Influence of Carbonate-Based Additives on the Electrochemical Performance of Si NW Anodes Cycled in an Ionic Liquid Electrolyte

TitleInfluence of Carbonate-Based Additives on the Electrochemical Performance of Si NW Anodes Cycled in an Ionic Liquid Electrolyte
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2020
AuthorsStokes, K., Kennedy T., Kim G.-T., Geaney H., Storan D., Laffir F., Appetecchi Giovanni Battista, Passerini Stefano, and Ryan K.M.
JournalNano letters
Volume20
Pagination7011-7019
ISSN15306992
Abstract

Addition of electrolyte additives (ethylene or vinylene carbonate) is shown to dramatically improve the cycling stability and capacity retention (1600 mAh g-1) of Si nanowires (NWs) in a safe ionic liquid (IL) electrolyte (0.1LiTFSI-0.6PYR13FSI-0.3PYR13TFSI). We show, using postmortem SEM and TEM, a distinct difference in morphologies of the active material after cycling in the presence or absence of the additives. The difference in performance is shown by postmortem XPS analysis to arise from a notable increase in irreversible silicate formation in the absence of the carbonate additives. The composition of the solid electrolyte interphase (SEI) formed at the active material surface was further analyzed using XPS as a function of the IL components revealing that the SEI was primarily made up of N-, F-, and S-containing compounds from the degradation of the TFSI and FSI anions.

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URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85092943876&doi=10.1021%2facs.nanolett.0c01774&partnerID=40&md5=ffd5967c2adde72da7ae402d3374ed57
DOI10.1021/acs.nanolett.0c01774