Ultrahigh Energy Density Realized by a Single‐Layer β‐Co(OH)2 All‐Solid‐State Asymmetric Supercapacitor |
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| Authors: | Shan Gao Dr Yongfu Sun Fengcai Lei Liang Liang Jiawei Liu Wentuan Bi Prof Bicai Pan Prof Yi Xie |
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| Affiliation: | Hefei National Laboratory for Physical Sciences at Microscale, University of Science & Technology of China, Hefei, Anhui 230026 (P.R. China) |
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| Abstract: | 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. |
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| Keywords: | all‐solid‐state devices asymmetric supercapacitors energy materials oriented attachment thin films |
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