Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions.
Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions.
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DOI：
10.1126/sciadv.1600320
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发表时间：
2016-07
期刊：
影响因子：
13.6
通讯作者：
Koch DL
中科院分区：
文献类型：
--
作者：
Tikekar MD;Archer LA;Koch DL
固体电解质中固定阴离子的弹性变形抑制了金属枝晶电沉积。金属电沉积中离子传输驱动的不稳定性导致了形态不稳定性和枝晶的出现，这引起了人们的重新关注，因为需要采取缓解策略来提高锂电池的可充电性和安全性。通过在电解液中固定一部分阴离子以减小金属电极处的电场，可以减缓这些形态不稳定性的增长速度。我们分析了固定阴离子固体电解质弹性变形的作用，并结合隔板弹性和修正输运的作用，提出了在大电流密度范围内影响平面沉积稳定性的理论。我们发现，即使在相对较高的电流密度下，在具有中等聚合物样机械模量的电解质/分离器中，只要有一小部分阴离子固定在分离器中，也可以很容易地实现稳定的电沉积。
Elastic deformation in solid electrolytes with immobilized anions suppresses dendritic electrodeposition of metals. Ion transport–driven instabilities in electrodeposition of metals that lead to morphological instabilities and dendrites are receiving renewed attention because mitigation strategies are needed for improving rechargeability and safety of lithium batteries. The growth rate of these morphological instabilities can be slowed by immobilizing a fraction of anions within the electrolyte to reduce the electric field at the metal electrode. We analyze the role of elastic deformation of the solid electrolyte with immobilized anions and present theory combining the roles of separator elasticity and modified transport to evaluate the factors affecting the stability of planar deposition over a wide range of current densities. We find that stable electrodeposition can be easily achieved even at relatively high current densities in electrolytes/separators with moderate polymer-like mechanical moduli, provided a small fraction of anions are immobilized in the separator.