Facile preparation of holey Anderson-type polyoxometalate/polyaniline/graphene nanocomposites for supercapacitors

Holey Fe-Anderson-type polyoxometalate/polyaniline/graphene (PPG) hybrid materials were first prepared by anchoring Anderson-type polyoxometalates [FeMo6O24H6](3-) (FeMo6) onto graphene modified with polyaniline via a facile hydrothermal treatment. The as-prepared materials exhibited an excellent electrochemical performance with a high specific capacitance of 1366 F g(-1) at 1 A g(-1) and outstanding cycling stability (97.6% capacitance retention after 5000 cycle times). The uptake of polyaniline/FeMo6 nanoparticles on graphene not only provided the pseudocapacitance but also weakened the aggregation between the graphene layers, resulting in a higher surface area compared with pure graphene. In addition, the AC//PPG-15 asymmetric supercapacitor device showed a high energy density of 24.65 W h kg(-1) at a low power density of 326.25 W kg(-1) and good cycling stability (94.82% capacitance retention after 5000 cycles). Hence, the as-prepared PPG hybrid materials in this work possess tremendous potential as electrodes for high-performance supercapacitors.