An Intermediate-Temperature High-Performance Na–ZnCl2 Battery
An Intermediate-Temperature High-Performance Na–ZnCl2 Battery
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DOI：
10.1021/acsomega.8b02112
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发表时间：
2018-11
期刊：
影响因子：
4.1
通讯作者：
Xiaochuan Lu;H. Chang;Jeff F. Bonnett;N. Canfield;Keeyoung Jung;V. Sprenkle;Guosheng Li
中科院分区：
文献类型：
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作者：
Xiaochuan Lu;H. Chang;Jeff F. Bonnett;N. Canfield;Keeyoung Jung;V. Sprenkle;Guosheng Li
Na−β-氧化铝电池（NBB）是将可再生能源资源整合到电网中的最有前途的储能技术之一。在NBBs家族中，Na-NiCl 2电池在过去十年中得到了广泛的研究，因为它具有较低的工作温度，更好的安全性和良好的电池性能。Na-NiCl 2电池的主要问题之一是材料成本，这主要来自电池阴极中的Ni金属。作为替代，Zn比Ni便宜得多，并且在阴极中用Zn代替Ni可以显著降低成本。在这项工作中，我们研究了Na-ZnCl 2电池在190 °C下的性能和反应机理。确定了两步可逆反应。在充电的第一步骤期间，NaCl与Zn反应以产生带状Na 2 ZnCl 4层。该层形成在NaCl-Zn界面处，而不是覆盖Zn颗粒的表面，这导致优异的电池速率能力。在第二步中，生成的Na 2 ZnCl 4逐渐消耗，在Zn颗粒表面形成ZnCl 2。所形成的ZnCl 2覆盖了Zn颗粒的大部分表面积，并且与第一步骤相比显示出有限的倍率性能。我们得出结论，第二步的这种有限的性能是由于ZnCl 2钝化Zn颗粒，这阻断了NaCl-Zn阴极的电子通路。
The Na−β-alumina battery (NBB) is one of the most promising energy storage technologies for integrating renewable energy resources into the grid. In the family of NBBs, Na–NiCl2 battery has been extensively studied during the past decade because it has a lower operating temperature, better safety, and good battery performance. One of the major issues with the Na–NiCl2 battery is material cost, which is primarily from Ni metal in the battery cathode. As an alternative, Zn is much cheaper than Ni, and replacing Ni with Zn in the cathode can significantly reduce the cost. In this work, we investigate the performance and reaction mechanism for a Na–ZnCl2 battery at 190 °C. Two-step reversible reactions are identified. During the first step of charging, NaCl reacts with Zn to produce a ribbon-type Na2ZnCl4 layer. This layer is formed at the NaCl–Zn interface rather than covering the surface of the Zn particles, which leads to an excellent cell rate capability. During the second step, the produced Na2ZnCl4 is gradually consumed to form ZnCl2 on the surface of Zn particles. The formed ZnCl2 covers most of the surface area of the Zn particles and shows a limited rate capability compared to that of the first step. We conclude that this limited performance of the second step is due to the passivation of Zn particles by ZnCl2, which blocks the electron pathway of the NaCl–Zn cathodes.