Literature Seminar Abstract:

Multivalent cations hold promise for dramatically increasing battery capacity over lithium ion technology, as each atom can provide multiple electrons, as opposed to one (e.g. Mg ➞ Mg2+ + 2e- v. Li ➞ Li+ + e-). However, the additional charge on multivalent cations slows their motion through solids. This slow cation mobility can be overcome at elevated temperatures, but room temperature ionic mobility is required for practical applications. Recently, the Ceder group used computational techniques to screen viable candidate structures, and then synthesized and characterized promising candidates to identify Mg2+ mobility of ~10-4-10-5 S cm-1 in a spinel material, MgSc2Se4, at 298K [1]. This report is the first to identify magnesium mobility in an inorganic solid at room temperature, and begins to identify the design rules necessary to realize practical solid-state multivalent ion conductors.

[1] Canepa, Bo, Gautam, Key, Richards, Shi, Tian, Wang, Li, and Ceder, “High magnesium mobility in ternary spinel chalcogenides”, Nature Communications, 2017 8(1), 1759.