Polycrystalline VO2(M) with well-dispersed crystalline zones for enhanced electroactivity of lithium-ion batteries

Constructing polycrystalline structure is an effective strategy to improve the electrochemical performance of electrode materials. To enhance the electroactivity of anisotropic VO2(M), polycrystalline VO2(M) with well-dispersed crystalline zones is successfully synthesized by a facile one-step hydrothermal method, and then their electrochemical performances as an anode of lithium-ion batteries are systematically explored. Results show that the synergistic effect of crystalline zones and amorphous matrices in polycrystalline structure can dramatically activate the anisotropic VO2(M) electrode, which contributes to increasing the electroactive zones and facilitating the charge transfer kinetics. Compared with single-crystal VO2(M), polycrystalline VO2(M) shows the significantly enhanced electrochemical performance, delivering a high reversible capacity of 476 mAhg(-1) at 100 mAg(-1) after 150 cycles, which is far superior to the theoretical capacity and the reported mixture of VO2(M)and VO2(B). This work opens up new insights for the activation of anisotropic electrode materials. (C) 2019 Elsevier B.V. All rights reserved.