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 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 and Na metal anodes as well as transition metal oxides, Prussian blue analogs and polyanion-type cathodes. Advanced characterization techniques are shortly discussed to shed light into the complex instability mechanisms in Na-based electrodes. We also delved into several material-based strategies to design next-generation Na electrodes for improved performance.