In the past few decades, supercapacitor (SC) has attracted great attention due to its significant advantages over traditional rechargeable battery systems, such as high power density, fast charge-discharge rate, long cycle life and environmental friendliness [1].Up to now, supercapacitors have been widely used in backup power, electric vehicles, mobile power and so on [2,3].However, the relatively low theoretical energy density restricts the increasing demands for supercapacitors in different fields [4].As has been reported, the energy storage ability of supercapacitors is directly affected by the electrode materials [5].On this account, considerable efforts have been paid to explore various new electrode materials with enhanced energy storage capacity.