"Fast galvanic lithium corrosion involving a Kirkendall-type mechanism"

Dingchang Lin: Yayuan Liu, Yanbin Li, Yuzhang Li, Allen Pei, Jin Xie, William Huang  and Yi Cui; Nature Chemistry, 04/01/19.

Additional Authors: Yayuan Liu, Yanbin Li, Yuzhang Li, Allen Pei, Jin Xie, William Huang  and Yi Cui

Abstract:

Developing a viable metallic lithium anode is a prerequisite for next-generation batteries. However, the low redox potential of lithium metal renders it prone to corrosion, which must be thoroughly understood for it to be used in practical energy-storage devices. Here we report a previously overlooked mechanism by which lithium deposits can corrode on a copper surface. Voids are observed in the corroded deposits and a Kirkendall-type mechanism is validated through electrochemical analysis. Although it is a long-held view that lithium corrosion in electrolytes involves direct charge-transfer through the lithium–electrolyte interphase, the corrosion observed here is found to be governed by a galvanic process between lithium and the copper substrate—a pathway largely neglected by previous battery corrosion studies. The observations are further rationalized by detailed analyses of the solid–electrolyte interphase formed on copper and lithium, where the disparities in electrolyte reduction kinetics on the two surfaces can account for the fast galvanic process.