VO₂ (D) submicron-spherical hierarchical structures as novel anode materials for aqueous lithium-ion batteries

Vanadium dioxide (VO₂) material has been deemed as a potential anode candidate for aqueous lithium-ion batteries. Among its diversified polymorphs, the latest discovered VO₂ (D) receives the fewest reports on its application in energy storage. Herein, we successfully utilized a template-free solvothermal method to prepare VO₂ (D) submicron-spherical hierarchical structures, constructed with colibacillus-like nanorods. The VO₂ (D) submicron-spheres were applied as an active anode material into the aqueous lithium-ion battery, which exhibited suitable working potential. Furthermore, VO₂ (D)-based full cell with LiMn₂O₄ as the cathode demonstrated high discharge capacity, good rate capability, and excellent cycling stability. The structural evolution, valence states of the VO₂ (D) electrode, and impedance variation of the full cell during cycling were investigated. The work reveals the potential of VO₂ (D) as a novel anode material for aqueous lithium-ion batteries.