VO 2 (B) is a promising cathode candidate for aqueous zinc ion batteries owing to its special tunnel lattice structure. However, the zinc storage mechanisms of VO 2 (B) are elusive over large voltage range, especially at the high potential. Via combined structure and composition characterizations such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy as well as electrochemical tests, it is demonstrated that VO 2 (B) goes through a conversion reaction when the potential approaching about 1.5 V during the first charging process. The obtained conversion product Zn 3 (OH) 2 V 2 O 7 ·2H 2 O shows high zinc ion storage capacity of 330 mA h g−1 at 0.1 A g−1, fast zinc ion diffusion kinetics, and high rate performances (130 mA h g−1 at 10 A g−1). This work provides a novel strategy for the rational design of electrode materials with large voltage range, especially for aqueous multi-valence ion batteries. Image 1 • A new in-situ electrochemical conversion mechanism of the VO 2 (B) cathode is proposed. • The conversion product Zn 3 (OH) 2 V 2 O 7 ·2H 2 O exhibits the enhanced battery performances. • This work provides a novel strategy to design electrode materials with large voltage range. [ABSTRACT FROM AUTHOR]