Complex hydrides as room-temperature solid electrolytes for rechargeable batteries

• Published in: Applied physics. A, Materials science & processing Vol. 122; no. 3; pp. 1 - 6
• Main Authors: de Jongh, P. E., Blanchard, D., Matsuo, M., Udovic, T. J., Orimo, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2016
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Coordination compounds; Electric batteries; Electrolytes; Hydrogen-based energy storage; Invited Paper; Lithium; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Rechargeable batteries; Solid electrolytes; Solvents; Strategy; Surfaces and Interfaces; Thin Films; Metal Hydride; Solid Electrolyte; High Ionic Conductivity; TiS2; LiBH4
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-016-9807-2

A central goal in current battery research is to increase the safety and energy density of Li-ion batteries. Electrolytes nowadays typically consist of lithium salts dissolved in organic solvents. Solid electrolytes could facilitate safer batteries with higher capacities, as they are compatible with Li-metal anodes, prevent Li dendrite formation, and eliminate risks associated with flammable organic solvents. Less than 10 years ago, LiBH 4 was proposed as a solid-state electrolyte. It showed a high ionic conductivity, but only at elevated temperatures. Since then a range of other complex metal hydrides has been reported to show similar characteristics. Strategies have been developed to extend the high ionic conductivity of LiBH 4 down to room temperature by partial anion substitution or nanoconfinement. The present paper reviews the recent developments in complex metal hydrides as solid electrolytes, discussing in detail LiBH 4 , strategies towards for fast room-temperature ionic conductors, alternative compounds, and first explorations of implementation of these electrolytes in all-solid-state batteries.