Research HighlightsComplex hydride electrolytes: A platform towards divalent metal-ion batteries
04/24/2023
From demonstrating Ca2+ conduction to implementing Zn2+ and Mg2+ conductions
Dr. Kazuaki Kisu measuring the electrochemical performance for developed battery.
To address the ever-increasing demand for portable energy, scientists have been exploring alternative battery chemistries that can both surpass the energy density of lithium-ion (Li+) batteries, and use abundant, environment-friendly materials for battery production. One such strategy focuses on isolating solid-state electrolytes (SSEs) that are highly conductive to divalent ions such as Ca2+, Zn2+, and Mg2+.
One pioneering example is a 2021 article by Kisu, Orimo et al. from AIMR, who designed a SSE using the closo-type complex hydride system1. Here, the authors demonstrated a new monocarborane counterion-based electrolyte that conducts Ca2+ ions without harmful byproducts (e.g., CaF2), opening a new path towards studying divalent-ion conduction.
Newly developed all-solid-state divalent metal batteries.
Since then, Kisu, Orimo et al. have made significant progress, notably in promoting of Zn2+ and Mg2+ conductions using a neutral-molecule addition approach. Recently, the authors have shown that in the MB12H12∙nH2O (n = 0–12 and M = Zn, Mg) complex hydride system, the inclusion of water molecules into the crystal structure promotes divalent-ion conductivities compared to the anhydrous crystal2.
“By using the neutral-molecule addition approach to tailor closo-type complex hydride systems, we have demonstrated that the conduction of many divalent metal ions by SSEs is possible,” says Kisu. “With Ca2+, Zn2+, and Mg2+ conductions, we have developed a complex-hydride platform that will accelerate all-solid-state divalent metal-ion battery research.”
(Author: Patrick Han)
References
- Kisu, K., Kim, S., Shinohara, T., Zhao, K., Züttel, A. & Orimo, S. Monocarborane cluster as a stable fluorine‑free calcium battery electrolyte. Scientific Reports 11, 7563 (2021). | article
- Kisu, K., Dorai, A., Kim, S., Hamada, R., Kumatani, A., Horiguchi, Y., Sato, R., Sau, K., Takagi, S. & Orimo, S. Fast divalent conduction in MB12H12∙12H2O (M = Zn, Mg) complex hydrides: effects of rapid crystal water exchange and application for solid-state electrolytes. Journal of Materials Chemistry A 10, 24877 (2022). | article
This research highlight has been approved by the authors of the original article and all information and data contained within has been provided by said authors.
