Research progress on electrode materials and electrolytes for supercapacitors

Supercapacitors have great potential applications for electronic devices, and energy recyling and storage areas owing to their high power density, long cycle life, high safety and excellent performance at low temperatures. The electrode materials and electrolytes are two key factors that influence their performance. The electrode materials used in supercapacitors include carbon materials such as activated carbons, carbon nanotubes, graphene, carbon nanofibers and carbon nano-onions, metal oxides, conductive polymers and their composites. The electrolytes are aqueous electrolytes, organic electrolytes or ionic liquids. Here research progress on the electrode materials and liquid electrolytes for supercapacitors is summarized, their advantages and disadvantages are analyzed, and new electrode materials and electrolytes are suggested.