Reserch

New complex hydrides exhibiting lithium fast-ion conduction at room temperature

2009/10/30

  Division of Hydrogen Functional Materials, in collaboration with Swiss Federal Institutes (EMPA and ETH-Zürich) and Graduate School of Engineering, Tohoku University, has developed new complex hydrides exhibiting lithium fast-ion conduction at room temperature. The hydrides consisting of plural complex anions [(BH4)- and (NH2)-] exhibit lithium-ion conductivity of nearly 10,000 times higher than those of the conventional hydrides with single complex anion. This study demonstrates an important research direction on searching for advanced lithium-ion conductors and solid-electrolytes. This work was supported by Global COE program of Tohoku University, Integrated Project of ICC-IMR, and KAKENHI Grant-in-Aid for Scientific Research (A); and the results were published in Journal of the American Chemical Society (online, October 26th, 2009).

Fig: Occupation sites for Li+ ions with different tetrahedral coordination of complex anions.  Li4(BH4)(NH2)3 consisting of plural complex anions [(BH4)- and (NH2)-] exhibits  lithium-ion conductivity of nearly 10,000 times higher than that of  the conventional hydride Li(BH4) (and Li(NH2)) with single complex anion.

Fig: Occupation sites for Li+ ions with different tetrahedral coordination of complex anions. 
Li4(BH4)(NH2)3 consisting of plural complex anions [(BH4)- and (NH2)-] exhibits lithium-ion conductivity of nearly 10,000 times higher than that of the conventional hydride Li(BH4) (and Li(NH2)) with single complex anion.