Advances in MoO3-based supercapacitors for electrochemical energy storage

With the ever-increasing demands for environmental and economical electronic devices, the development of supercapacitors is promising but challenging. Molybdenum trioxide (MoO3) has been extensively studied as supercapacitor electrode material due to the good stability and multiple oxidation states, while the state-of-the-art MoO3-based supercapacitors are still far from industrial application in energy storage devices. In order to give a clear and complete comprehension on the advances of MoO3 as supercapacitor electrode material, the MoO3 is reviewed in detail by emphasizing the morphologies and electrochemical performance of pure MoO3 nanostructure and MoO3-based composites, highlighting the pros and cons of different MoO3 architectures. It is proposed that the introduction of oxygen vacancies, fabrication of hierarchical nanostructure and utilizing the synergistic effect of composites are considered as effective strategies for pursuing outstanding electrochemical characteristics. Moreover, the remaining challenges and future research prospects are reasonable suggested based on the spotlight of MoO3 based supercapacitors. Understanding of these optimal techniques in relation to the improved electrochemical performance of MoO3 is important and may serves as bright lamp for investigating the MoO3 applied in energy storage.