1. Expanding the Phase Space for Halide-Based Solid Electrolytes: Li-Mg-Zr-Cl Spinels.
- Author
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Rom CL, Yox P, Cardoza AM, Smaha RW, Phan MQ, Martin TR, and Maughan AE
- Abstract
Chloride-based solid electrolytes are intriguing materials owing to their high Li
+ ionic conductivity and electrochemical compatibility with high-voltage oxide cathodes for all-solid-state lithium batteries. However, the leading examples of these materials are limited to trivalent metals (e.g., Sc, Y, and In), which are expensive and scarce. Here, we expand this materials family by replacing the trivalent metals with a mix of di- and tetra-valent metals (e.g., Mg2+ and Zr4+ ). We synthesize Li2 Mg1/3 Zr1/3 Cl4 in the spinel crystal structure and compare its properties with the high-performing Li2 Sc2/3 Cl4 that has been reported previously. We find that Li2 Mg1/3 Zr1/3 Cl4 has lower ionic conductivity (0.028 mS/cm at 30 °C) than the isostructural Li2 Sc2/3 Cl4 (1.6 mS/cm at 30 °C). We attribute this difference to a disordered arrangement of Mg2+ and Zr4+ in Li2 Mg1/3 Zr1/3 Cl4 , which may block Li+ migration pathways. However, we show that aliovalent substitution across the Li2- z Mg1-3 z /2 Zrz Cl4 series between Li2 MgCl4 and Li2 ZrCl6 can boost ionic conductivity with increasing Zr4+ content, presumably due to the introduction of Li+ vacancies. This work opens a new dimension for halide-based solid electrolytes, accelerating the development of low-cost solid-state batteries., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)- Published
- 2024
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