Flexible Electrochemical Supercapacitors: A Review

Flexible supercapacitors (FSCs), especially wearable ones, have become a hotspot of research because of their advantages such as energy density, high specific capacitance, good mechanical properties, decent stability, and eco-friendliness. The storage mechanism in FSCs is either a faradaic mechanism in pseudocapacitors (PCs) or a non-faradaic mechanism as in double-layer supercapacitors (ELSCs). This review summarized the research progress for manufacturing electrodes from various types of materials, whereas carbon, metal oxides, or conductive polymers are utilized as electrodes. An overview of what researchers have performed in changing the original shape of materials and combining them to obtain flexible electrodes with good electrochemical performances. The review includes the presence of different types of electrolytes in the FSCs structure. Perspectives on the direction of future development of research in the field of FSCs are also discussed.