Nanocomposite Of Keggin Polyoxometalate And Their Electrochemical Performance Research

In recent yeas, Polyoxometalates (POMs) has gradually development extending from basic research to the field of energy and environment, which is combined with the development of national economy. Keggin polyoxometalates as an electrode material has attracted substantial interest, owing to its excellent symmetry, strongly acidic, reversible multi-electron redox behaviour and structural stability property etc, and improve the protonation and the electrochemical properties of conducting polymers such as polyaniline. It has been reported that the super-reduced state of PMo12, [PMo12O40]27-, could store 24 electrons exhibiting a large theoretical capacity. Nevertheless, it should be noted that electrochemical applications of POMs are in general largely restricted by formation of aggregates and dissolve. Aggregates of Keggin POMs powder would lead to some inevitable defects of its electrode materials, such as diminution of cycle stability and rate performance as anode materials for lithium ion batteries and supercapacitors. As a result, how to solve the above problems is the purpose of this project. It is that aggregates of POMs are in general largely restricted by synthesis of composite materials POM/CNT. So we have investigated POMs modified CNTs through the conducting agent of PANI in the current study.This paper is amid at solving the problems of electrochemical applications of POMs as electrode materials for lithium ion batteries and supercapacitors. The research content includes two aspects as follows:1. The application of lithium-ion batteries, the aniline monomer can be adsorbed onto MWNTs surface via n-n interactions, leads to the formation of PANI/MWNTs composite material. Further reaction of PMo12 with the PANI/MWNTs composite material via electrostatic interactions results in the novel PMo12/PANI/MWNTs nanocomposite. The investigation of the electrochemical behaviour of the PMo12/PANI/MWNTs nanocomposite as anode electrode showed an initial discharge capacity of 952 mAh·g-1, and sustained high discharge capacity of 1000 mAh·g-1 for up to 100 cycles with an exceptionally stable capacity performance. Such a very good performance of the PMo12/PANI/MWNTs nanocomposite as anode material highlights the great potential and the vast space for further exploration for the development of POM-based ternary nanocomposite systems as functional and highly modular electrode materials for energy applications.2. The application of supercapacitors, we successfully prepared for the PMo12-nVn/PANI/MWNTs nanocomposite utilizing a facile method. The investigation of the electrochemical behaviour of the PMo12-nVn /PANI/MWNTs nanocomposite as electrode material for supercapacitor showed high specific capacitance and Rate capacitance. Such a very good performance of the PMo12-nVn/PANI/MWNTs nanocomposite as electrode material highlights the great potential and the vast space for further exploration for the development of POM-based ternary nanocomposite systems as functional and highly modular electrode materials for energy applications.