A thermodynamically stable quasi-liquid interface for dendrite-free sodium metal anodes
A thermodynamically stable quasi-liquid interface for dendrite-free sodium metal anodes
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用于无枝晶钠金属阳极的热力学稳定的准液体界面
DOI：
10.1039/d0ta02016h
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发表时间：
2020-04-14
影响因子：
11.9
通讯作者：
Ding, Yi
中科院分区：
文献类型：
--
作者：
Zhang, Qi;Hu, Min;Ding, Yi
枝晶相关电池退化是钠金属阳极实际应用的关键挑战。在这里，我们提出，将少量的汞掺入钠中，产生一种独特的准液体界面，提供长期的循环稳定性。该汞齐层允许在电解质-电极界面处的快速电子转移和钠迁移，这显著提高了超过5000小时的循环性能，实际上期望的容量为2 mA h cm-2，电流密度为8 mA cm-2。原位光学显微镜分析证实，枝晶成核和生长可以显着抑制汞齐保护阳极。原型全电池还表现出大大改善的速率和长期循环稳定性。这些有前途的结果提供了新的观点，通过引入低熔点金属，从而消除钠金属电池的实际发展的树枝状形态的钠电沉积的监管。
Dendrite-associated cell degradation is a key challenge to the practical application of sodium metal anodes. Here, we present that incorporation of a tiny amount of mercury into sodium generates a unique quasi-liquid interface that affords long-term cycling stability. This amalgam layer allows fast electron transfer and sodium migration at the electrolyte–electrode interphase, which significantly promote the cycling performance over 5000 h with a practically desired capacity of 2 mA h cm−2 and a current density of 8 mA cm−2. In situ optical microscopy analyses confirm that dendrite nucleation and growth can be remarkably suppressed with the amalgam-protected anodes. Prototype full cells also demonstrate a much improved rate and long-term cycling stability. These promising results provide new perspectives on the regulation of sodium electrodeposition by introducing low-melting metals and hence the elimination of the dendritic morphology for the practical development of sodium metal batteries.