Description:
<jats:p> Efficient magnesium electrolytes are crucial in order to realize rechargeable magnesium batteries, which are an important contender for post-lithium-ion-battery technology.<jats:sup>1,2</jats:sup> Due to the divalent positive charge carried by the Mg<jats:sup>2+</jats:sup> ion, magnesium mobility is difficult to achieve and so far Mg ion conductivity in inorganic solids has only been reported for few systems and typically, conductivities above 10<jats:sup>-5</jats:sup> Scm<jats:sup>-1</jats:sup>
<jats:sub> </jats:sub>are only reached above 400 °C, see Figure 1. </jats:p>
<jats:p>In this work, we demonstrate that partially chelated ethylenediamine magnesium borohydride complexes show promise as solid-state Mg conductors with unprecedented high conductivity of up to 6x10<jats:sup>-5 </jats:sup>Scm<jats:sup>-1</jats:sup>already at 70 °C. The compounds are easily prepared by a mechanochemical reaction and allow for reversible Mg plating/stripping at 60 °C, which is recognized to be a major challenge in magnesium ion batteries. </jats:p>
<jats:p>While the electrochemical stability, limited by the ethylenediamine ligand, must be improved to reach competitive energy densities, our results demonstrate that partially chelated Mg<jats:sup>2+</jats:sup>complexes represent a promising platform for the development of an all-solid-state magnesium battery. </jats:p>
<jats:p> References </jats:p>
<jats:p>1 D. Aurbach, G. S. Suresh, E. Levi, A. Mitelman, O. Mizrahi, O. Chusid and M. Brunelli, <jats:italic>Adv. Mater.</jats:italic>, 2007, <jats:bold>19</jats:bold>, 4260–4267. </jats:p>
<jats:p>2 H. D. Yoo, I. Shterenberg, Y. Gofer, G. Gershinsky, N. Pour and D. Aurbach, <jats:italic>Energy Environ. Sci.</jats:italic>, 2013, <jats:bold>6</jats:bold>, 2265. </jats:p>
<jats:p>3 S. Ikeda, M. Takahashi, J. Ishikawa and K. Ito, <jats:italic>Solid State Ionics</jats:italic>, 1987, <jats:bold>23</jats:bold>, 125–129. </jats:p>
<jats:p>4 N. Imanaka, Y. Okazaki and G. Adachi, <jats:italic>J. Mater. Chem.</jats:italic>, 2000, <jats:bold>10</jats:bold>, 1431–1435. </jats:p>
<jats:p>5 N. Imanaka, Y. Okazaki and G. Adachi, <jats:italic>Ionics</jats:italic>, 2001, <jats:bold>7</jats:bold>, 440–446. </jats:p>
<jats:p>6 S. Higashi, K. Miwa, M. Aoki and K. Takechi, <jats:italic>Chem. Commun.</jats:italic>, 2014, <jats:bold>50</jats:bold>, 1320–2.</jats:p>
<jats:p> </jats:p>
<jats:p>
<jats:inline-formula>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="308fig1.jpeg" xlink:type="simple" />
</jats:inline-formula>
</jats:p>
<jats:p>Figure 1</jats:p>
<jats:p />