Abstract
Lithium-ion batteries are an important component in mobile electronics; however, their modest energy density makes them less than ideal for use in all-electric vehicles or localized grid residential/commercial energy storage. Multivalent-ion batteries (MIBs), including Mg2+, are promising high-energy density technologies that are cheaper and more abundant than lithium. Realizing the high theoretical energy density of MIBs requires the native multivalent-ion metal to be used as the anodic electrode, where densely controlled metal plating and stripping has yet to be achieved. The mechanisms governing plating/stripping of MIBs and the resulting microstructural impact on the battery performance must be understood before MIBs can be employed commercially. Understanding the role that the solid electrolyte interface has on multivalent-ion metal plating/stripping may lead to solutions for controlling reversible anodic cycling.
Recent advances in cryogenic electron microscopy(cryo-EM) preparation have allowed for scanning transmission electron microscopy (STEM) investigation of intact solid/liquid interfaces and electron-beam-sensitive materials. Here we present results of our chemical and microstructural investigation of plated and stripped Mg2+ anodes, collected with cryo-FIB preparation, cryo-transfer, and cryo-STEM. Details will be presented on the anode porosity, grain orientation maps, chemical maps from the electrode/electrolyte interfaces, and high-resolution structural imaging of the electrode interfaces.
This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government.