Ammine Magnesium Borohydride Nanocomposites for All-Solid-State Magnesium Batteries
Ammine Magnesium Borohydride Nanocomposites for All-Solid-State Magnesium Batteries
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DOI：
10.1021/acsaem.0c01599
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
Yigang Yan;J. Grinderslev;Mathias Jørgensen;Lasse N. Skov;J. Skibsted;T. Jensen
中科院分区：
文献类型：
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作者：
Yigang Yan;J. Grinderslev;Mathias Jørgensen;Lasse N. Skov;J. Skibsted;T. Jensen
镁电池被认为是锂离子电池时代之后未来储能的有前途的解决方案。然而，镁电池的发展因缺乏合适的电解质而受到阻碍。本文介绍了一种基于氨合硼氢化镁复合物的Mg ~（2+）固体电解质Mg（BH_4）_2·xNH_3，其电导率约为0.001。比母体化合物高三个数量级（x = 1、2、3和6）。由Mg（BH 4）2·xNH 3复合物和MgO纳米颗粒形成的纳米复合材料在室温下表现出优异的Mg 2+电导率，其数量级为10-5 S cm-1，在中温（约10-3 S cm-1）下表现出优异的Mg 2+电导率。70 °C），具有用于Mg 2+传导的活化能Ea = 108 kJ/mol（1.12 eV）和高热稳定性（Tdec = 120 °C）。利用固态核磁共振、粉末X射线衍射和透射电子显微镜的表征表明，高的Mg 2+电导率归因于Mg 2+（BH 4）2·xNH 3的非晶化，从而导致高度动态的状态。该纳米复合材料与Mg金属阳极相容，并允许在对称电池中稳定的Mg电镀/剥离（至少100个循环）。这些结果代表了固态多价离子导体的重大进步，本文针对Mg 2+进行了证明。
Magnesium batteries are considered promising solutions for future energy storage beyond the lithium-ion battery era. However, the development of magnesium batteries is hindered by the lack of suitable electrolytes. Here we present solid Mg2+ electrolytes based on ammine magnesium borohydride composites, Mg(BH4)2·xNH3, which have conductivities ca. three orders of magnitude higher than the parent compounds (x = 1, 2, 3, and 6). A nanocomposite formed by the Mg(BH4)2·xNH3 composite and MgO nanoparticles exhibits outstanding Mg2+ conductivity of the order of 10–5 S cm–1 at room temperature and around 10–3 S cm–1 at moderate temperature (ca. 70 °C), with an activation energy for Mg2+ conduction of Ea ∼108 kJ/mol (1.12 eV) and high thermal stability (Tdec = 120 °C). Characterization using solid-state nuclear magnetic resonance, powder X-ray diffraction, and transmission electron microscopy reveals that the high Mg2+ conductivity is attributed to amorphization of Mg(BH4)2·xNH3 resulting in a highly dynamic state. This nanocomposite is compatible with a Mg metal anode and allows stable Mg plating/stripping (at least 100 cycles) in a symmetric cell. The results represent a major advancement of solid-state multivalent ion conductors here demonstrated for Mg2+.