Chelate mediated synthesis of novel Mn2V2O7 and MnV2O6 materials with hierarchical morphological structures and improved redox behavior via multi-walled carbon nanotubes for asymmetric supercapacitors

Designing different nano/microstructural geometries with porous properties is of great attention, allowing impressive electrochemical properties in energy storage technology. Herein, we report the manganese vanadium oxides of Mn 2 V 2 O 7 and MnV 2 O 6 with different morphologies by a most adaptable hydrothermal technique using three types of chelating agents (citric acid, ethylenediaminetetraacetic acid, and hexamethylenetetramine). The materials reveal a hierarchical thorny structure, i.e., an orientation form of microrods and nanorod bundles, and their comparative electrochemical analysis is performed. Furthermore, the thorny sphere morphology of MVO material is combined with the multi-walled carbon nanotubes and it reveals the enhancement in the specific capacity as compared to pristine. This electrode material exhibits superior capacity retention of 97% even after 4000 cycles at 5 A g −1 with its corresponding coulombic efficiency of 99%. Additionally, a pouch-like asymmetric supercapacitor device exhibits a high energy and power density values of 26.6 Wh kg −1 and 2875 W kg −1 , respectively. Eventually, various low voltage electronic devices such as a mortar fan and blue light-emitting diodes are powered-up using the devices to test the real-time applications in the field of energy storage. • The novel MVO structures were prepared with three types of chelating agents. • The effect of chelates on the physiochemical properties of MVO was studied. • The MVO-H/MWCNTs electrode delivered a specific capacity of 111 mAh g −1 at 1 A g −1 . • The MVO-H/MWCNTs electrode exhibited a capacity retention of 97% over 4000 cycles.