Oxygen Vacancy Engineering in Tin(IV) Oxide Based Anode Materials toward Advanced Sodium-Ion Batteries

A high theoretical capacity of approximately 1400 mA h g⁻¹ makes SnO₂ a promising anode material for sodium-ion batteries (SIBs). However, large volume expansion, poor intrinsic conductivity, and sluggish reaction kinetics have greatly hindered its practical application. The controlled creation of oxygen vacancy (OV) defects allows the intrinsic properties of SnO₂ to be effectively modulated, but related work concerning SIBs is still lacking. In this Minireview, the mechanism of failure of SnO₂ electrodes is discussed and an overview of recent progress in the general synthesis of OV-containing SnO₂ materials and the feasible detection of OVs in SnO₂ is presented. The use of OV-containing SnO₂-based anode materials in SIBs is also reviewed. Finally, challenges and future opportunities to engineer OVs for semiconductor oxides are examined.