Corresponding Author

Dong-feng XUE(dongfeng@ciac.ac.cn)


Supercapacitors have high power density and long cycle life compared with battery systems, but they still suffer from low energy density at the same time. In order to increase the energy density of supercapacitors, we have developed a new type of pseudocapacitor, called colloidal ion supercapacitor, which can directly use commercial metal salts as electrode materials and form electroactive matter by in-situ electrochemical reactions without the need of additional materials synthesis processes. Colloidal ion supercapacitor can fully utilize the redox reaction of metal cations with multiple oxidation states, which can completely release the stored electrical energy of multiple-valence cations, leading to high energy density. Due to the presence of colloidal cation ions in the colloidal ion supercapacitor, the diffusion length of electrons and ions can be shortened, leading to high redox reaction kinetics and high power density. Both high energy density and high power density can exist in one supercapacitor devices, called colloidal ionic supercapacitor. This review outlines the concept, basis and the development of colloidal ion supercapacitors, the latest research progresses and the facing future challenges. We hope that colloidal ion supercapacitor can advance the development of the next generation of high-performance electrochemical energy storage devices.

Graphical Abstract


supercapacitor, electroactive cation, pseudocapacitor, electrochemical reaction, rare earth

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