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Ultrahigh Energy Density Realized by a Single‐Layer β‐Co(OH) 2 All‐Solid‐State Asymmetric Supercapacitor
Author(s) -
Gao Shan,
Sun Yongfu,
Lei Fengcai,
Liang Liang,
Liu Jiawei,
Bi Wentuan,
Pan Bicai,
Xie Yi
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201407836
Subject(s) - supercapacitor , capacitance , nanodevice , materials science , power density , solid state , nanotechnology , layer (electronics) , energy storage , electrode , energy density , chemical engineering , optoelectronics , power (physics) , chemistry , engineering physics , physics , quantum mechanics , engineering
A conceptually new all‐solid‐state asymmetric supercapacitor based on atomically thin sheets is presented which offers the opportunity to optimize supercapacitor properties on an atomic level. As a prototype, β‐Co(OH) 2 single layers with five‐atoms layer thickness were synthesized through an oriented‐attachment strategy. The increased density‐of‐states and 100 % exposed hydrogen atoms endow the β‐Co(OH) 2 single‐layers‐based electrode with a large capacitance of 2028 F g −1 . The corresponding all‐solid‐state asymmetric supercapacitor achieves a high cell voltage of 1.8 V and an exceptional energy density of 98.9 Wh kg −1 at an ultrahigh power density of 17 981 W kg −1 . Also, this integrated nanodevice exhibits excellent cyclability with 93.2 % capacitance retention after 10 000 cycles, holding great promise for constructing high‐energy storage nanodevices.