Progress on metal oxides -based supercapacitors and their applications

Electrochemical -capacitors(supercapacitors)have received considerable attention as new energy storage systems because of th eir excellent properties,such as hi gher power density compared with rechargeable batteries,higher energy density compared with conventional capacitors,large capa -city,broad operating temperature r ange and long cycle life.The purpose of this review is to survey the fundamental principles,charac teristics,and applications of supercapacitors,especially the recent progress of researches on supercapacitors using metal oxides as electro de materials.