Metal ions and 3D microstructure engineering enable V2O5·4VO2 enhanced lithium storage.

• The 3D microflower-like V 2 O 5 ·4VO 2 with Ga-doped cathode is synthesized by a green hydrothermal method. • Combining the two modification methods of constructing three-dimensional micro-nanostructures and metal ion doping to enhance the electrochemical performance of V 2 O 5 ·4VO 2. • The prepared GVO2 with Ga-doped exhibits both a high specific capacity (as high as 322.47 mAh·g−1 at 0.1 A·g−1), excellent high rate performance (224.72 mAh·g−1 at 1 A·g−1) and favorable cycling stability with 81.09 % capacity retention. Within various lithium-ion batteries (LIBs) cathode materials, vanadium oxides are considered to be a potential candidate for the next-generation LIBs cathode materials owing to their abundant reserves, low cost and higher theoretical specific capacity. However, its inferior structural stability leads to suboptimal cycling stability as vanadium oxides are used as cathode materials for lithium-ion batteries. Metal ions and 3D microstructure engineering are considered to be an effective method which is used to enhance the electrochemical performance of cathode materials for lithium-ion batteries. In this paper, the 3D microflower-like V 2 O 5 ·4VO 2 with Ga-doped is synthesized with Ga(NO 3) 3 as the gallium source. The appropriate amount of Ga ion doping does not only optimize the microscopic morphology of the samples but also extends the cell volume of V 2 O 5 ·4VO 2 , so as to increase the conductivity and lithium ion diffusion coefficient of the electrode materials. At the Ga doping amount of n (Ga3+)/n (V5+)=4.54 %, the prepared 3D microflower-like V 2 O 5 ·4VO 2 with Ga-doped exhibits both a high specific capacity (as high as 322.47 mAh·g−1 at 0.1 A·g−1), excellent high rate performance (224.72 mAh· g −1 at a current density of 1 A·g−1) and favorable cycling stability (81.09 % capacity retention after 200 cycles at 1 A·g−1). Consequently, the 3D microflower-like V 2 O 5 ·4VO 2 with Ga-doped provides great development potential as a cathode material for next-generation LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]