Polyoxomolybdate–Polypyrrole/Reduced Graphene\nOxide Nanocomposite as High-Capacity Electrodes for Lithium Storage

Abstract

A nanocomposite\npolyoxomolybdate (PMo₁₂)–polypyrrole\n(PPy)/reduced graphene oxide (RGO) is fabricated by using a simple\none-pot hydrothermal method as an electrode material for lithium-ion\nbatteries. This facile strategy skillfully ensures that individual\npolyoxometalate (POM) molecules are uniformly immobilized on the RGO\nsurfaces because of the wrapping of polypyrrole (PPy), which avoids\nthe desorption and dissolution of POMs during cycling. The unique\narchitecture endows the PMo₁₂–PPy/RGO with the lithium\nstorage behavior of a hybrid battery–supercapacitor electrode:\nthe nanocomposite with a lithium storage capacity delivers up to 1000\nmAh g^–1 at 100 mA g^–1 after 50\ncycles. Moreover, it still demonstrates an outstanding rate capability\nand a long cycle life (372.4 mAh g^–1 at 2 A g^–1 after 400 cycles). The reversible capacity of this\nnanocomposite has surpassed most pristine POMs and POMs-based electrode\nmaterials reported to date.