Abstract
All-solid-state Li-ion batteries (ASSBs), considered to be potential next-generation energy storage devices, require solid electrolytes (SEs). Thiophosphate-based materials are popular, but these sulfides exhibit poor anodic stability and require specialty coatings on lithium metal oxide cathodes. Moreover, electrode designs aimed at high energy density are limited by their narrow electrochemical stability window. Here, we report new mixed-metal halide Li3-xM1-xZrxCl6 (M = Y, Er) SEs with high ionic conductivity-up to 1.4 mS cm-1 at 25 °C-that are stable to high voltage. Substitution of M (M = Y, Er) by Zr is accompanied by a trigonalto-orthorhombic phase transition, and structure solution using combined neutron and single-crystal X-ray diffraction methods reveal a new framework. The employment of >4 V-class cathode materials without any protective coating is enabled by the high electrochemical oxidation stability of these halides. An ASSB showcasing their electrolyte properties exhibits very promising cycling stability up to 4.5 V at room temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 533-539 |
| Number of pages | 7 |
| Journal | ACS Energy Letters |
| Volume | 5 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 14 2020 |
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, U.S. Department of Energy.