A 2.4-V asymmetric supercapacitor based on cation-intercalated manganese oxide nanosheets in a low-cost “water-in-salt” electrolyte
The main challenge for aqueous asymmetric supercapacitors (ASCs) is the relatively low voltage, which significantly diminishes the energy density of the device. Here, cation-intercalated manganese oxide nanosheets Na 0.55 Mn 2 O 4 ·1.5H 2 O (NaMnO) are synthesized via a facile molten salts method. W...
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Published in | Ionics Vol. 25; no. 12; pp. 6007 - 6015 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.12.2019
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The main challenge for aqueous asymmetric supercapacitors (ASCs) is the relatively low voltage, which significantly diminishes the energy density of the device. Here, cation-intercalated manganese oxide nanosheets Na
0.55
Mn
2
O
4
·1.5H
2
O (NaMnO) are synthesized via a facile molten salts method. We find that the electrode potential window for NaMnO nanosheets can be extended to 1.2 V using a low-cost and safe superconcentrated sodium perchlorate (NaClO
4
) “water-in-salt” (WIS) electrolyte. To construct the asymmetric supercapacitor, the as-prepared NaMnO nanosheets and activated carbon (AC) with a potential window of − 1.2–0 V are used as the positive and negative electrode, respectively. A high-voltage 2.4-V NaMnO//AC aqueous ASC in the concentrated NaClO
4
WIS electrolyte is successfully assembled, which exhibited excellent rate performance (the highest power density of 24.0 kW kg
−1
) as well as good cycling stability (94.9% capacitance retention over 20,000 cycles at 5 A g
−1
). This low-cost WIS electrolyte provides new opportunities for developing high-voltage aqueous ASCs with high energy and high power densities. |
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ISSN: | 0947-7047 1862-0760 |
DOI: | 10.1007/s11581-019-03141-y |