Sn-based metal oxides and sulfides anode materials for Na ion battery

The extensive search for high-capacity negative electrodes for sodium-ion batteries had led to the investigation of various nanomaterials capable of storing sodium ions in their structures through the combined conversion and alloying reactions. Among many nanomaterials, tin metal oxides and tin metal sulfides are considered highly promising compounds due to their high theoretical capacities. However, there have been growing concerns regarding the inability of these materials to deliver substantial reversible capacities, which often leads to an incomplete conversion-alloying reaction. In this review, particular attention is paid to the recent advances in the development of Sn-based anodes for SIBs to understand in detail the obstacles hindering the full utilization of these materials. We first present a short overview of sodium storage mechanisms of Sn-based materials and the synthetic strategies used to prepare various Sn-based nanostructures. We focus on the approaches to mitigate the structural deformation of these materials. In addition, we highlight efforts devoted to understanding the formation and evolution of solid-electrolyte interface during the continuous sodiation-desodiation process, which is significantly different from the phenomena in the lithium-ion batteries and thus requires different approaches. This review further addresses the standing challenges in developing Sn-based materials and points to future research directions in hope to usher the practical applications of the sodium-ion batteries.