Flower-Like VO₂(B)@C Structure: High Rate Capacity and Stability as Lithium-Ion Batteries

In this report, we describe flower-like VO₂(B)@C nanostructures, which exhibit spherical particles on radially protruding nanorods and are synthesized through a mild hydrothermal approach. Improved electrochemical performance can be easily acquired by controlling the amount of the sucrose. When the amount of sucrose is 0.32 g, the first discharge capacity of VO₂(B)@C nanostructures reaches 238.9 mAh g^-1. At a high current density of 2000 mA g^-1, flower-like VO₂(B)@C nanostructures exhibit 2.5-fold higher capacity than VO without sucrose. As the rate is reduced to 100 mA g^-1, a high discharge capacity of 144.4 mAh g^-1 (79% of the original capacity) is recovered, manifesting good rate reversibility. This performance is derived from the unique flower-like structural feature with low crystallinity, which could significantly suppress irreversible Li⁺ trapping and improve Li⁺ diffusion kinetics. The well discharge capacity and capacity retention show that VO₂(B)@C has considerable potential for use in industry applications.