Researchers have compared bulk scandium doping and surface scandium coating in a special type of cathodes for sodium-ion batteries. Both approaches improved cycling stability, with the coated full cell retaining 91.2% of its initial capacity after 300 cycles, while structural analyses revealed distinct bulk- and surface-stabilization mechanisms.
Researchers from Tokyo University of Science and the Institute of Science Tokyo in Japan have investigated how scandium (Sc) doping and coating can improve the durability and performance of sodium-ion batteries (SIBs) within the cathode element of the battery structure.
More specifically, they have introduced the scandium ion Sc3+ into an O3-Na[Ni1/2Mn1/2]O2 either by bulk doping or by surface coating. O3-Na[Ni1/2Mn1/2]O2 is attractive for SIBs because it offers relatively high capacity. However, it suffers from severe capacity loss during cycling, which the researchers sought to reduce by introducing Sc³.
“Sc ions can be incorporated either into the bulk structure or through an external coating. Both can improve the cycling performance, but the underlying mechanisms have not been elucidated,” explained Shinichi Kumakura, who led the research group. “In this study, we explored how scandium improves battery performance of SIBs through both doping and coating, clarifying their distinct mechanisms.”
