Abstract
All-solid-state Li-ion batteries that utilize nonflammable solid electrolytes are considered potential candidates for sustainable energy storage systems. Although sulfide solid electrolytes have been widely explored, their lack of electrochemical stability above 2.7 V requires the application of protective coating layer on 4 V-class cathode materials, whereas the superior oxidative stability of chloride solid electrolytes enables their direct use with such high voltage cathodes. Here, we report a metastable trigonal phase of Li3YbCl6with an ionic conductivity of 1.0 × 10-4S·cm-1and mixed-metal halide solid electrolytes, Li3-xYb1-xZrxCl6, with conductivities up to 1.1 mS·cm-1at room temperature. Combined neutron, single-crystal, and powder X-ray diffraction methods reveal that Zr-substitution for Yb in Li3YbCl6triggers a trigonal-to-orthorhombic phase transition and forms new, lower energy pathways for Li-ion migration. All-solid-state cell cycling with uncoated >4 V-class cathodes is enabled by the high electrochemical oxidation stability of the mixed-metal halide solid electrolyte.
| Original language | English |
|---|---|
| Pages (from-to) | 930-938 |
| Number of pages | 9 |
| Journal | ACS Materials Letters |
| Volume | 3 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 5 2021 |
Funding
We gratefully acknowledge BASF for funding through the Battery and Electrochemistry Network, and the Natural Sciences and Engineering Council of Canada through a doctoral scholarship to K.K. and the Canada Research Chair and Discovery Grant programs to L.F.N. Neutron diffraction measurement at the POWGEN instrument at Oak Ridge National Laboratory, Spallation Neutron Source, was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy.
