Insights into Electrochemical Sodium Metal Deposition as Probed with in Situ 23Na NMR
Insights into Electrochemical Sodium Metal Deposition as Probed with in Situ 23Na NMR
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DOI：
10.1021/jacs.5b12423
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发表时间：
2016-02-17
影响因子：
15
通讯作者：
Grey, Clare P.
中科院分区：
文献类型：
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作者：
Bayley, Paul M.;Trease, Nicole M.;Grey, Clare P.
近年来，由于钠电池具有成本和丰富性等众多有利特性，研究人员重新对钠电池产生了兴趣。在这里，我们研究了利用原位核磁共振研究这种电池化学的可行性，重点关注钠金属阳极。 NMR信号的量化表明Na金属沉积物的形态与极高的表面积相关，沉积物不断积累，即使在恒电流循环的情况下也是如此。 Na金属的电化学循环的两种机制对Na阳极的使用具有明显的影响：在低电流下，Na沉积物在电流反向时被部分去除，而在高电流下，在初始阶段基本上没有去除沉积物。在较长的时间内，高电流在循环过程中显示出明显更多的沉积物积累，再次表明当电流反向时去除这些结构的效率要低得多。
Sodium batteries have seen a resurgence of interest from researchers in recent years, owing to numerous favorable properties including cost and abundance. Here we examine the feasibility of studying this battery chemistry with in situ NMR, focusing on Na metal anodes. Quantification of the NMR signal indicates that Na metal deposits with a morphology associated with an extremely high surface area, the deposits continually accumulating, even in the case of galvanostatic cycling. Two regimes for the electrochemical cycling of Na metal are apparent that have implications for the use of Na anodes: at low currents, the Na deposits are partially removed on reversing the current, while at high currents, there is essentially no removal of the deposits in the initial stages. At longer times, high currents show a significantly greater accumulation of deposits during cycling, again indicating a much lower efficiency of removal of these structures when the current is reversed.