Recent Advances and Applications of Inorganic Electrides

Abstract

Electrides, accommodating excess electrons in lattice voids as anions, have attracted considerable attention in both fundamental research and application development because of their interesting properties, such as ultralow work functions, high electronic mobility, high catalytic activity, and anisotropic electronic and optical properties. Recently, much research progress has been made in both types and applications of inorganic electrides because of the high stability. In this Perspective, we aim to summarize the recent development of inorganic electrides discovered and proposed by experiment and theoretical calculations, highlighting the main applications, including catalysis, metal-ion batteries, superconductivity, magnetism, and organic light-emitting diodes. We provide insights into the role of anionic electrons in electrides playing in the stability and properties. Finally, the problems, challenges, and opportunities are presented, which provide an outlook for future research.

Nackte Elektronen mit Potenzial

“…Das sind Verbindungen von Metalllösungen in flüssigem Ammoniak und primä-ren Aminen, denen Komplexbildner zugesetzt wurden, etwa Kronen ether oder Kryptanden. Im Jahr 1983 isolierten Ahmed Ellaboudy und Coautoren das erste kristalline Elektrid, [Cs( [18]-Krone-6) 2 ] + e − . Das Cäsium kat ion darin wird von zwei Kronen 0ethern koordiniert, und die losgelösten Elektronen befinden sich in Hohlräumen zwischen diesen Komplexen.…”

“…Besonders 2-D-Elektride gelten in der Batterieforschung als vielversprechende Elektrodenmaterialien. 18) In Analogie zu Graphen findet sich bereits die Nomenklatur…”

Hydrogenation induced magnetic and electronic transitions in monolayer electride Gd$_2$C: A first-principles study

“…The electride materials are deemed to possess excess electrons, so called free electron gas, serving as anions 1,2 . These excess electrons locate on the lattice voids but not bind to certain nuclei 1,2 .…”

“…The electride materials are deemed to possess excess electrons, so called free electron gas, serving as anions 1,2 . These excess electrons locate on the lattice voids but not bind to certain nuclei 1,2 . According to the dimensionality of the free electron gas in the electrides, they can be classified into zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) types 3 .…”

Design of semiconducting electrides via electron-metal hybridization: the case of Sc2C

“…Challenges in energy storage, electronics, and catalysis motivate the search for exotic materials with extreme properties, and electrides-crystals with bare electrons trapped at stoichiometric concentrations 1-3 -offer some of the most exceptional. These electrons have been ejected from atomic orbitals to reside in vacant lattice sites and, because they are so weakly bound, are better electron donors than alkali metals [4][5][6] , can offer electrical conductivity that rivals silver, and can catalyze challenging reactions. These properties have led to the exploration of electrides in applications where electron-rich materials are needed: N2 and CO2 reduction 7,8 , battery electrodes 9,10 , and electron emitters [11][12][13] .…”