Evaluating Solid-Electrolyte Interphases for Lithium and Lithium-free Anodes from Nanoindentation Features

• Published in: Chem Vol. 6; no. 10; pp. 2728 - 2745
• Main Authors: Wang, Wei-Wei, Gu, Yu, Yan, Hao, Li, Sha, He, Jun-Wu, Xu, Hong-Yu, Wu, Qi-Hui, Yan, Jia-Wei, Mao, Bing-Wei
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 08.10.2020
• Subjects: atomic force microscopy; copper current collector; electrochemical cycling performance; implantable SEIs; lithium anode; lithium-free type of anode; mechanical property; nanoindentation; solid-electrolyte interphase; Young’s modulus; Young’s modulus; lithium anode; electrochemical cycling performance; copper current collector; solid-electrolyte interphase; nanoindentation; mechanical property; lithium-free type of anode; implantable SEIs; atomic force microscopy; SDG7: Affordable and clean energy
• ISSN: 2451-9294; 2451-9294
• DOI: 10.1016/j.chempr.2020.07.014

The morphology and mechanical property of SEIs for lithium anodes crucially affect the electrochemical cycling performance of Li-metal batteries such as Li-S and Li-O2 batteries. Herein, we establish the standards for rapidly assessing SEIs for Li and Li-free type of anodes by AFM nanoindentation features toward prediction of corresponding electrochemical performances. A series of single-layered and multi-layered SEIs with known composition and structures are purposely constructed. A set of unique nanoindentation features representative of mechanical properties of the basic SEIs are formed, serving as the standards for rapidly assessing the mechanical properties and electrochemical performances of unknown SEIs together with their Young’s modulus, smoothness, and thickness. To validate the applicability of the method, SEIs formed by electrochemical aging and formed on Cu substrates are further evaluated. Our work not only contributes to understanding the influence of SEIs on cycling performances but also provides a rapid way for screening SEIs. [Display omitted] •Basic and conceptual SEIs with known composition and spatial structures are created•Mechanical properties of SEIs are represented by AFM nanoindentation features•Nanoindentation features are correlated with the electrochemical performances of SEIs•The standards for rapidly assessing SEIs from AFM nanoindentation are established Lithium metal has been regarded as the most promising anode candidate for next-generation high energy battery technologies such as Li-S and Li-O2 batteries. However, the practical application of Li metal as anode still suffers from the intertwined instable SEI and dendrite growth, for which the morphology and mechanical property of the SEI are the key influencing factors. Here, we demonstrate that SEIs on Li and Li-free anodes can be evaluated from AFM nanoindentation features. A set of representative nanoindentation features of a series of SEIs with defined chemical composition and spatial arrangement are correlated with their electrochemical cycling performances, and they form the standards for rapidly assessing the qualities of unknown practical SEIs on Li anode and Li-free type of anode. This work is beneficial to not only understanding the mechanism behind electrochemical behavior of Li anodes but also constructing superior SEIs for Li and Li-free anodes. A set of unique AFM nanoindentation features representative of mechanical properties of SEIs on Li-metal anodes and Li-free anodes are obtained. These features are further correlated with the electrochemical performance of corresponding anodes and form the standards for rapidly assessing the qualities of unknown SEIs.