Core–shell VPO4/C anode materials for Li ion batteries: Computational investigation and sol–gel synthesis

Pristine VPO4 is a ground-state magnetic semiconductor, disclosed by density functional theory computations; therefore, core–shell VPO4/C composites were proposed and prepared via a sol–gel route. X-ray diffraction confirms the phase of orthorhombic vanadium phosphate, and scanning electron microscopy and transmission electron microscopy show that VPO4 particles are coated with amorphous carbon film of ∼8 nm in thickness to form core–shell nanostructures. Galvanostatic charge/discharge and cyclic voltammetry tests demonstrate that both the initial and reversible lithium storage capacities of VPO4 were apparently enhanced due to the carbon coating. Core–shell structures can effectively improve the electrochemical performances of phosphate-based Li-ion battery materials.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Core–shell VPO4/C composites were explored as anode materials for Li ion batteries. ► Core–shell VPO4/carbon composites were prepared via a sol–gel route. ► Li storage capacity of VPO4 was apparently enhanced due to carbon coating.