The Peculiarity of Chemo-Mechanical Instabilities in Na-Based Battery Electrodes

Abstract

Rechargeable Na-based batteries have received tremendous attention as a post-lithium energy storage device due to their lower cost and competitive energy density for grid-storage and transportation applications. However, the practical performance of Na-based batteries suffers from severe chemo-mechanical instabilities in electrode materials associated with structural and interfacial deformations during cycling. Mitigating these instabilities is crucial for achieving higher performance in Na-based batteries for widespread commercialization and industrial utility. This perspective focuses on the state-of-the-art in Na metal and Na-ion batteries, with an emphasis on chemo-mechanical phenomena in electrode materials. The perspective points out the current challenges in hard carbon, alloy, and Na metal anodes as well as transition metal oxides, Prussian blue analogs, and polyanion-type cathodes together with issues related to cathode–anode electrolyte interphase. Advanced characterization techniques are briefly discussed to shed light on the complex instability mechanisms in Na-based electrodes. We also delve into several material-based strategies to design next-generation Na electrodes for improved performance.