Abstract
Li3N is an excellent protective coating material for lithium electrodes with very high lithium-ion conductivity and low electronic conductivity, but the formation of stable and homogeneous coatings is technically very difficult. Here, we show that protective Li3N coatings can be simply formed by the direct reaction of electrodeposited lithium electrodes with N2 gas, whereas using battery-grade lithium foil is problematic due to the presence of a native passivation layer that hampers that reaction. The protective Li3N coating is effective at preventing lithium dendrite formation, as found from unidirectional plating and plating–stripping measurements in Li–Li cells. The Li3N coating also efficiently suppresses the parasitic reactions of polysulfides and other electrolyte species with the lithium electrode, as demonstrated by scanning transmission X-ray microscopy, X-ray photoelectron spectroscopy, and optical microscopy. The protection of the lithium electrode against corrosion by polysulfides and other electrolyte species, as well as the promotion of smooth deposits without dendrites, makes the Li3N coating highly promising for applications in lithium metal batteries, such as lithium–sulfur batteries. The present findings show that the formation of Li3N can be achieved with lithium electrodes covered by a secondary electrolyte interface layer, which proves that the in situ formation of Li3N coatings inside the batteries is attainable.
Original language | English |
---|---|
Pages (from-to) | 39198-39210 |
Number of pages | 13 |
Journal | ACS Applied Materials & Interfaces |
Volume | 15 |
Issue number | 33 |
Early online date | 8 Aug 2023 |
DOIs | |
Publication status | Published - 23 Aug 2023 |
Bibliographical note
Financial support from EPSRC through the Faraday Institution LiSTAR programme (EP/S003053/1, grant FIRG014) and an early career fellowship to N.G.A. (EP/N024303/1) are gratefully acknowledged. The authors also gratefully acknowledge support from Diamond for beam time at the I08 (SP1860 and SP20639) and I09 (S122619) beamlines. Conventional X-ray photoelectron (XPS) data collection was performed at the EPSRC National Facility for XPS (“HarwellXPS”), operated by Cardiff University and UCL, under contract no. PR16195. We also acknowledge Dr. Mark Isaacs for helpful scientific discussions regarding the XPS measurements.Data Availability Statement
Raw data used in the preparation of this article are available from the University of Southampton repository at https://doi.org/10.5258/SOTON/D2733.The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.3c04897.
Keywords
- lithium metal anode
- protective coating
- artificial SEI
- lithium-sulfur battery
- polysulfides
- XPS
- STXM
- operando optical microscopy