Sarra et al - Solid–Electrolyte Interface Formation on Si Nanowires in Li-Ion Batteries: The Impact of Electrolyte Additives - Batteries 9.3 (2023): 148. - NANOTECHNOLOGY RESEARCH THE UNIVERSITY OF LIMERICK

Sarra et al – Solid–Electrolyte Interface Formation on Si Nanowires in Li-Ion Batteries: The Impact of Electrolyte Additives – Batteries 9.3 (2023): 148.

March 23, 2023 – 12:45 pm – Comments Off

Angelo Sarra^1,†,‡, Sergio Brutti^1,2,3,† , Oriele Palumbo¹, Francesco Capitani⁴, Ferenc Borondics⁴, Giovanni Battista Appetecchi⁵, Nicholas Carboni¹, Syed Abdul Ahad⁶, Hugh Geaney⁶, Kevin Ryan⁶ and Annalisa Paolone^1,*

¹Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Piazzale Aldo Moro 5, 00185 Rome, Italy
²Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
³GISEL-Centro di Riferimento Nazionale per i Sistemi di Accumulo Elettrochimico di Energia, INSTM, Via G. Giusti 9, 50121 Firenze, Italy
⁴Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, CEDEX, 91192 Gif-sur-Yvette, France
⁵Agenzia Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA), Materials and Physicochemical Processes Technical Unit (SSPT-PROMAS-MATPRO), Via Anguillarese 301, 00123 Rome, Italy
⁶Department of Chemical Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
Corresponding Author: Annalisa Paolone (annalisa.paolone@roma1.infn.it)

^†These authors contributed equally to this work.
^‡Present address: Microscopy Center, University of L’Aquila, Via Vetoio, 67100 L’Aquila, Italy

Received: 29 November 2022 / Revised: 20 February 2023 / Accepted: 24 February 2023 / Published: 26 February 2023
Link to Paper: https://www.mdpi.com/2313-0105/9/3/148

Abstract

The morphological changes of Si nanowires (Si NWs) cycled in 1:1 ethylene–carbonate (EC)/diethyl–carbonate (DEC) with or without different additives, fluoroethylene carbonate (FEC) or vinylene carbonate (VC), as well as the composition of the deposited solid–electrolyte interphase layer, are investigated by a combination of experimental microscopic and spectroscopic techniques. Scanning electron microscopy and optical spectroscopy highlight that the NW morphology is better preserved in samples cycled in the presence of FEC and VC additives compared to the additive-free electrolyte. However, only the use of FEC is capable of slightly mitigating the amorphization of silicon upon cycling. The solid electrolyte interphase (SEI) formed over the Si NWs cycled in the additive-free electrolyte is richer in organic and inorganic carbonates compared to the SEI grown in the presence of the VC and FEC additives. Furthermore, both additives are able to remarkably limit the degradation of the LiPF₆ salt. Overall, the use of the FEC-additive in the carbonate-based electrolyte promotes both morphological and structural resilience of the Si NWs upon cycling, thanks to the optimal composition of the SEI layer.
Keywords: silicon; negative electrodes; Li-ion batteries; microscopy; solid electrolyte interphase