Nanostructured morphology control for efficient supercapacitor electrodes

Abstract
The fast growing interest in portable electronic devices and electric vehicles has stimulated extensive research in high performance energy storage devices, such as supercapacitors. Nanostructured electrodes can achieve high electrochemical performances in supercapacitors owing to their high surface atom ratio, tuneable texture and unique size-dependent properties that can afford effective electrolyte diffusion and improved charge transportation and storage during charging–discharging. This review reports on the recent progress in designing and fabricating different kinds of nanostructured electrodes, including electrical double layer based electrodes such as porous carbons and graphene, and Faradic reaction based electrodes such as metal oxides/hydroxides and conductive polymers. Furthermore, the review also summarizes the advances of hybrid electrodes, which store charges by both mechanisms, such as porous carbons–metal oxides/hydroxides, porous carbons–conductive polymers, graphene–metal oxides/hydroxides, and graphene–conductive polymers. Finally, we provide some perspectives as to the future directions of this intriguing field.