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 Mn2V2O7 and MnV2O6 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.

Automated summary

The study focuses on designing different nano/microstructural geometries with porous properties to enhance electrochemical performance in energy storage technology. By utilizing a hydrothermal technique with various chelating agents, different morphologies of manganese vanadium oxides were synthesized, showing promising electrochemical properties. The combination of thorny sphere morphology of MVO material with multi-walled carbon nanotubes led to improved specific capacity, and the resulting asymmetric supercapacitor device exhibited high energy and power density values. Various low voltage electronic devices were successfully powered-up by these devices for real-time applications in energy storage.