Deciphering the Lithium-ion Conduction Mechanism of LiH in Solid-Electrolyte Interphase.

Lithium hydride (LiH) has been widely recognized as the critical component of the solid-electrolyte interphase (SEI) in Li batteries. Although the formation mechanism and structural model of LiH in SEI have been extensively reported, the role in electro-performance of LiH in SEI is still ambiguous and has proven challenging to explored due to the complicated structure SEI and the lack of advanced in-situ experimental technology. In this study, the isotopic exchange experiments combined with isotopic tracer experiments was applied to solidly illustrate the superior conductivity and Li + conduction behavior of the LiH in natural SEI. Importantly, in-situ TEM analysis was utilized to visualize the self-electrochemical decomposition of LiH, which is significantly distinctive from LiF and Li 2 O. The critical experimental evidence discovered by our work demonstrates ion transport behaviors of key components in the SEI, which is imperative for designing novel SEI and augurs a new area in optimizing the performance of lithium batteries. This article is protected by copyright. All rights reserved.