Mesoporous MnCo2S4 nanosheet arrays as an efficient catalyst for Li–O2 batteries
In: Nanoscale, Jg. 10 (2018), S. 15588-15599
Online
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Zugriff:
Ternary metal sulfides and ternary metal oxides have received much attention as potential electrodes for high performance rechargeable batteries. Herein, MnCo2S4 nanosheets are grown on carbon paper (MCS/CP) via facile electrodeposition followed by low temperature vulcanization for application in Li–O2 batteries for the first time. The electrochemical performance of freestanding, binder-free MCS/CP oxygen electrodes is compared with those prepared from MnCo2O4 nanosheets on CP (MCO/CP). The MCS/CP electrode delivers an extremely high initial specific capacity of 10 760 mA h g−1, twice that of MCO/CP. The former electrode sustains 96 cycles at an upper limit capacity of 500 mA h g−1 at 200 mA g−1, whereas the latter counterpart survives only a few cycles with a poor round trip efficiency. The superior performance of MCS/CP is in part proven by the four times higher electrical conductivity and 250% higher lithium diffusion coefficient than MCO/CP. In addition, the 3D interconnected web of 2D MCS nanosheets offers a few micrometer open voids to accommodate discharge products and a large surface area with internal mesopores providing abundant active sites. The density functional theory calculations reveal a lower adsorption energy for LiO2 on the surface of MCS than on MCO, which is responsible for the lower OER overpotential and the higher catalytic ability of MCS/CP. The predicted density of states signifies metallic properties of MCS in agreement with the high electrical conductivity of MCS/CP.
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Mesoporous MnCo2S4 nanosheet arrays as an efficient catalyst for Li–O2 batteries
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Autor/in / Beteiligte Person: | Liu, Jiapeng ; Ciucci, Francesco ; Sadighi, Zoya ; Jang Kyo Kim |
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Zeitschrift: | Nanoscale, Jg. 10 (2018), S. 15588-15599 |
Veröffentlichung: | Royal Society of Chemistry (RSC), 2018 |
Medientyp: | unknown |
ISSN: | 2040-3372 (print) ; 2040-3364 (print) |
DOI: | 10.1039/c8nr03942a |
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