Protective coating for stable cycling of Li-metal batteries based on cellulose and single-ion conducting polymer

Vargas Ordaz, Mariana (author), Pavlin, Nejc (author), Gastaldi, Matteo (author), Gerbaldi, Claudio (author), Dominko, Robert (author)

The thermodynamically unstable interface between metallic lithium and electrolyte poses a major problem for the massive commercialization of Li-metal batteries. In this study, we propose the use of a multicomponent protective coating based on cellulose modified with dimethylthexylsilyl group (TDMSC), single-ion conducting polymer P(LiMTFSI), and LiNO$_3$ (TDMSC-P(LiMTFSI)-LiNO$_3$, namely PTL). The coating shows its positive effect by increasing the Coulombic efficiency in Li || Cu cells from 95.9 and 98.6% for bare Li, to >99.3% for Li coated (Li@PTL), with 1 M LiFSI in FEC:DEC and 1 M LiFSI in DME electrolyte, respectively. Symmetrical Li || Li PTL-coated cells exhibit a much more prolonged and stable cycling with a slower increase in overpotential compared to bare Li cells. Li@PTL anodes enable improved cycling of Li@PTL/LFP cells compared to noncoated cells in liquid electrolytes. In this respect, inhibition of high surface area lithium growth is confirmed through postcycling scanning electron microscopy. Remarkably, dendrite-free galvanostatic cycling is demonstrated in laboratory-scale solid-state battery cells assembled with LFP composite cathode (catholyte configuration with PEO + LiTFSI as ionically conducting binder) and a cross-linked PEO-based solid polymer electrolyte. The PTL protective coating enables improved stability of Li metal batteries in combination with smooth transport of Li$^+$ at the electrode−electrolyte interface and homogeneous lithium coating, highlighting its promising prospects in enhancing the performance and safety of lithium metal batteries by properly tuning the synergy between the coating components.

• Language: English
• Keywords: protective coating, lithium metal batteries, cellulose, single ion conductor, P(LiMTFSI)
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 68237–68246
• Numbering: Vol. 16, iss. 49
• PID: 20.500.12556/RUL-166072
• UDC: 544.5/.6
• ISSN on article: 1944-8252
• DOI: 10.1021/acsami.4c13335
• COBISS.SI-ID: 219780611
• Publication date in RUL: 19.12.2024

Record is a part of a journal

• Title: ACS applied materials & interfaces
• Shortened title: ACS appl. mater. interfaces
• Publisher: American Chemical Society
• ISSN: 1944-8252
• COBISS.SI-ID: 516049433

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: elektrokemija, litij-ionske baterije, celuloza, prevodniki