Crystallographic Phase-Dependent Electrochemical Properties of Layered Hydroxides for Energy Applications

Abstract

Layered Hydroxides (LHs) have garnered increasing attention for their versatility and potential in various applications, particularly in energy storage and conversion. These materials exhibit notable chemical tunability and structural flexibility; however, misassignments between common phases – such as layered double hydroxides (LDHs), alpha, and beta phases – are still occasionally encountered, despite the distinct properties of each. This review focuses on the influence of crystallographic phases on the electrochemical properties of LHs, a topic that remains relatively underexplored. We discuss several synthetic approaches that allow for precise tuning of these phases, along with the most suitable characterization techniques, including synchrotron-based methods, and highlight key spectroscopic features that aid in accurate phase identification. Additionally, we provide an overview of recent work from our group, which underscores the importance of crystallographic phases in shaping the electrochemical behaviour of LHs in alkaline environments, particularly for applications such as the oxygen evolution reaction. A more detailed understanding of these phase-dependent properties is essential for the rational design of more efficient electrode materials, which could further contribute to the advancement of energy conversion and storage technologies.