ADVANCED ENERGY-STORAGE SYSTEM OF HIGHVOLTAGE SYMMETRIC SUPERCAPCITORS FABRICATED WITH N-CONTAINING CARBON MATERIAL

摘要

In view of the fast-growing market for electric vehicles andnportable electronic devices, supercapacitors with efficient powerndelivery are projected to be highly promising electrochemical energynstorage (EES) systems in further power elites.1-3 However, thendiscouraging energy storage capacity of supercapacitors always castnshadows on popularizing its commercial applications.4 Targeting atnenhancing the energy density, researchers have focused onnfabricating advanced systems such as the Li-ion capacitors andnhybrid battery-supercapacitors.5-8 Aqueous electrolytes with highnionic conductivity, superb safety benefits, low cost andnenvironmental-friendly implementation make aqueous-based EESndevices more desirable for practical applications.9-11 In this respect,nasymmetric supercapacitors in aqueous media are verified withnattracting advantages and can be reversibly operated with a highnvoltage window around 1.4-2.0 V.12,13 Unfortunately, the energyndensity of this system is still restricted by the low electrical doublelayerncapacitors (EDLCs) of carbon anodes (< 200 F g-1) and isnfurther undermined by its large mass loading to match thencapacitance imbalance with pseudocapacitive cathodes.