Mechanically flexible energy storage devices, such as supercapacitors, with high energy density, comparable with those of rechargeable batteries, and long term device cycling ability (>50 000 cycles) are inevitably required for next-generation energy storage technologies. The energy density and overall performance of graphene/carbonaceous material electrodes in supercapacitors can be effectively engineered by combining with certain metal oxides/hydroxides/sulphides/phosphides, and conducting polymers. For this purpose, we have successfully developed a new class of hierarchical graphene/carbon framework, which are surface decorated with thin layers/nanofibers of transition metal oxide, hydroxides and sulphides/phosphides, such as MnxO4, NiO, Fe2O3 and Ni(OH)2. Taking MnxO4 as an example, a highly flexible Mn3O4/reduced graphene oxide (rGO) nanohybrid paper with high electrical conductivity and high mass loading of metal oxide nanofibers of >0.70 gcm?3 can be developed via a facile gel formation and subsequent electrochemical reduction. When assembled with reduced rGO paper/carbon network, some of these oxides/nonoxides give rise to flexible ASC devices with remarkable electrochemical performance.
Professor John Wang will also briefly introduce the Materials Science and Engineering Dept, National University of Singapore, where Materials Science is ranked the Asia Best.