Abstract
Solid electrolytes (SEs) have gained increased attention for their promise to enable higher volumetric energy density and enhanced safety required for future battery systems. SEs are not only a key constituent in all-solid-state batteries, but also important “protectors” of Li metal anodes in next-generation battery configurations, such as Li–air, Li–S, and redox flow batteries. The impedance at interfaces associated with SEs, e.g., internal grain/phase boundaries and their interfacial stability with electrodes, represents two key factors limiting the performance of SEs, yet analyzing these interfaces experimentally at the nano/atomic scale is generally challenging. A mechanistic understanding of the possible instability at interfaces and propagation of interfacial resistance will pave the way to the design of high-performance SE-based batteries. In this review, we briefly introduce the fundamentals of SEs and challenges associated with their interfaces. Next, we discuss experimental techniques that allow for atomic-to-microscale understanding of ion transport and stability in SEs and at their interfaces, specifically highlighting the applications of state-of-the-art and emerging ex situ and in situ transmission electron microscopy (TEM) and scanning TEM (STEM). Representative examples from the current literature that exemplify recent fundamental insights gained from these S/TEM techniques are highlighted. Applicable strategies to improve ion conduction and interfaces in SE-based batteries are also discussed. This review concludes by highlighting opportunities for future research that will significantly promote the fundamental understanding of SEs, specifically further developments in S/TEM techniques that will bring new insights into the design of high-performance interfaces for future electrical energy storage.
Original language | English |
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Pages (from-to) | 10571-10594 |
Number of pages | 24 |
Journal | Journal of Materials Science |
Volume | 54 |
Issue number | 15 |
DOIs | |
State | Published - Aug 15 2019 |
Funding
The preparation of this review was supported by the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility, and sponsored by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. ZDH gratefully acknowledges a Research Fellowship from the National Science Foundation under Grant No. DGE-1650044.