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Extraordinary Supercapacitor Performance of a Multicomponent and Mixed‐Valence Oxyhydroxide
Author(s) -
Kang Jianli,
Hirata Akihiko,
Chen Luyang,
Zhu Shengli,
Fujita Takeshi,
Chen Mingwei
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201500133
Subject(s) - supercapacitor , capacitance , electrolyte , electrochemistry , nanoporous , electrode , power density , valence (chemistry) , electrochemical window , materials science , current density , polarization (electrochemistry) , aqueous solution , chemical engineering , redox , inorganic chemistry , chemistry , nanotechnology , metallurgy , thermodynamics , power (physics) , ionic conductivity , physics , organic chemistry , quantum mechanics , engineering
We report a novel multicomponent mixed‐valence oxyhydroxide‐based electrode synthesized by electrochemical polarization of a de‐alloyed nanoporous NiCuMn alloy. The multicomponent oxyhydroxide has a high specific capacitance larger than 627 F cm −3 (1097±95 F g −1 ) at a current density of 0.25 A cm −3 , originating from multiple redox reactions. More importantly, the oxyhydroxide electrode possesses an extraordinarily wide working‐potential window of 1.8 V in an aqueous electrolyte, which far exceeds the theoretically stable window of water. The realization of both high specific capacitance and high working‐potential windows gives rise to a high energy density, 51 mWh cm −3 , of the multicomponent oxyhydroxide‐based supercapacitor for high‐energy and high‐power applications.