Abstract

The rapid development of flexible and wearable electronic devices has triggered considerable efforts in the research and development of this area. Having the advantages of high power density, wide operating temperature range, long lifetime, and excellent safety, supercapacitors have been researched for their application in flexible devices. An ideal flexible supercapacitor (FSC) would have high electrochemical performances and excellent mechanical deformability. This chapter reviews the recent advances of FSCs. Electrode materials, with the focus on nanocomposite-based FSCs, are first discussed. Owing to their excellent properties, carbon nanomaterials, including carbon nanotubes, carbon nanofibers, and graphene, have been combined with pseudocapacitive materials to fabricate nanocomposites. In this regard, carbon nanomaterial-incorporated nanocomposites (carbon-metal oxides, carbon-conducting polymers, and carbon-mxenes) that have been studied for FSCs are elucidated. This explanation is followed by the discussion about device configurations of nanocomposite-based FSCs, including one-dimensional fiber-shaped, two-dimensional film-shaped, and three-dimensional structural. Finally, the chapter summarizes efforts made to explore the practical applications of nanocomposite-based FSCs. Upon conclusion, the current challenges and future opportunities for nanocomposite-based FSCs are discussed.