Synergistic effect of V3O7/VO2 film electrodes as high-performance cathode materials for magnesium-ion batteries

• Published in: Solid state sciences Vol. 149; p. 107445
• Main Authors: He, Yang, Xu, Haiyan, Bian, Hanxiao, Ge, Qi, Li, Dongcai, Wang, Aiguo, Sun, Daosheng
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01.03.2024
• Subjects: Film electrode; High-performance; Low-temperature liquid-phase deposition; Magnesium-ion batteries; V3O7/VO2; V3O7/VO2; Low-temperature liquid-phase deposition; High-performance; Film electrode; Magnesium-ion batteries
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2024.107445

Magnesium-ion batteries have become important candidates for secondary batteries due to their low cost, dendrite-free and multivalent nature. However, the lack of structural stability of most electrode materials and the slow diffusion kinetics of Mg2+ have hindered the development of magnesium-ion batteries. In this work, V3O7/VO2 film electrodes were grown in situ on indium tin oxide conductive glass using a low-temperature liquid-phase deposition method. After calcination at different temperatures in a nitrogen atmosphere, it was concluded that the films calcined at 400 °C had an appropriate crystallinity and biphasic structure. With 0.5 M Mg(ClO4)2/PC as the electrolyte, the initial discharge capacity was 111.5 mA h m−2 at 100 mA m−2 and the stabilized capacity was 156.7 mA h m−2 after 100 cycles. According to high-resolution transmission electron microscopy, ex-situ X-ray diffraction, and X-ray photoelectron spectroscopy, V3O7, formed by the partial phase transformation of VO2, has an extraordinarily large interlayer space as the calcination temperature increases. It assisted VO2 to increase the Mg2+ transport channels and provided more active sites to promote diffusion kinetics (the average DMg2+ was 2.83 × 10−12 cm2 s−1). These results may provide a new idea for the use of V3O7/VO2 films as electrode materials for magnesium-ion batteries. [Display omitted] •V3O7/VO2 films were prepared by low temperature liquid phase deposition.•Partial phase change of VO2 to V3O7 during calcination.•The films on ITO substrates are easy to figure out the ion de/insertion mechanism.•V3O7, which has large layer spacing, assists VO2 in adding more ion diffusion channels.•The advantages of morphology and crystallinity make films have good properties.