Two positive effects with one arrow: modulating crystal and interfacial decoration towards high-potential cathode material

As the primary suppliers of cyclable sodium ions, O3-type layer-structured manganese-based oxides are recognized as highly competitive cathode candidates for sodium-ion batteries. To advance the development of high-energy sodium-ion batteries, it is crucial to explore cathode materials operating at high voltages while maintaining a stable cycling behavior. The orbital and electronic structure of the octahedral center metal element plays a crucial role in maintaining the octahedra structural integrity and improving Na+ ion diffusion by introducing heterogeneous chemical bonding. Inspired by the abundant configuration of extra nuclear electrons and large ion radius, we employed trace amounts of tungsten in this study. The obtained cathode material can promote the reversibility of oxygen redox reactions in the high-voltage region and inhibit the loss of lattice oxygen. Additionally, the formation of a Na2WO4 coating on the material surface can improve the interfacial stability and interface ions diffusion. It demonstrates an initial Coulombic efficiency (ICE) of 94.6% along with 168.5 mA h g−−1 discharge capacity within the voltage range of 1.9–4.35 V. These findings contribute to the advancement of high-energy sodium-ion batteries by providing insights into the benefits of tungsten doping and Na2WO4 coating on cathode materials.