Recent Progress of Regulation Factors on the Deposition of Sodium Anodes

Abstract

As the demand for portable electronic and electric vehicles increase, it is necessary to pursue batteries with longer cycle life, higher energy density, and overall better performance. Because lithium sources are limited and lithium metal is expensive, it is necessary to find alternatives. Rechargeable sodium (Na) batteries have attracted great research interest because of their high natural abundance, low cost of sodium resources, and electrochemical similarity with lithium batteries. However, despite the potential to become the next generation of energy storage, the application of sodium metal batteries is mainly hindered by sodium dendrites and "dead" sodium, which reduce battery coulombic efficiency, shorten battery life, and even cause safety problems. The formation of Na dendrites is mainly due to the uncontrolled Na deposition behavior of sodium ions in the absence of nucleation site regulation. Therefore, the sodium deposition is crucial to the final status of Na anodes. Here, we first analyze the growth mechanism of sodium dendrites, then review the research progress of nucleation sites on inhibiting the formation of sodium dendrites, and finally discuss the practical application of sodium batteries and the future challenges of metallic sodium anodes, hoping to stimulate more research interests of researchers.