Abstract
Li phosphorus oxynitride (LiPON) is one of a very few solid electrolytes that have demonstrated high stability against Li metal and extended cyclability with high Coulombic efficiency for all solid-state batteries (ASSBs). However, theoretical calculations show that LiPON reacts with Li metal. Here, we utilize in situ electron microscopy to observe the dynamic evolutions at the LiPON-Li interface upon contacting and under biasing. We reveal that a thin interface layer (∼60 nm) develops at the LiPON-Li interface upon contact. This layer is composed of conductive binary compounds that show a unique spatial distribution that warrants an electrochemical stability of the interface, serving as an effective passivation layer. Our results explicate the excellent cyclability of LiPON and reconcile the existing debates regarding the stability of the LiPON-Li interface, demonstrating that, though glassy solid electrolytes may not have a perfect initial electrochemical window with Li metal, they may excel in future applications for ASSBs.
| Original language | English |
|---|---|
| Pages (from-to) | 151-157 |
| Number of pages | 7 |
| Journal | Nano Letters |
| Volume | 21 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 13 2021 |
Funding
This work was sponsored by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The microscopy characterizations were completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. X.C. and J.N. acknowledge support from the UWMF Catalyst Program, UWM Research Growth Initiative (RGI), and National Science Foundation (NSF) #2013525.
Keywords
- Batteries
- In situ electron microscopy
- Interface
- Li metal
- LiPON
- Solid electrolyte