Embedding of Mg-doped V2O5 nanoparticles in a carbon matrix to improve their electrochemical properties for high-energy rechargeable lithium batteries

Abstract

Hierarchical Mg-doped V₂O₅@carbon (HVC) spheres were fabricated using poly(methacrylic acid) (PMAA) microgel as a microreactor. The monodisperse micron-sized spheres are formed from 200 nm particles, in which primary V₂O₅ nanoparticles are embedded uniformly in a carbon matrix to form a mulberry-like morphology. The effect of the Mg-doping level on the electrochemical properties of the as-prepared HVC spheres was studied. Benefitting from the unique morphology and chemical pre-insertion of Mg²⁺ ions, the Mg_0.10V₂O₅@C sample exhibited an excellent rate capability and stable cyclability when operated over the potential range of 1.5–4.0 V (vs. Li⁺/Li). The results suggest that these porous HVC spheres hold promise for use as high-energy-density cathode materials for rechargeable lithium batteries.