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Title: Highly porous, low band-gap Ni x Mn 3−x O 4 (0.55 ≤ x ≤ 1.2) spinel nanoparticles with in situ coated carbon as advanced cathode materials for zinc-ion batteries
Aqueous zinc ion batteries (ZIBs) are emerging as a highly promising alternative technology for grid-scale applications where high safety, environmental-friendliness, and high specific capacities are needed. It remains a significant challenge, however, to develop a cathode with a high rate capability and long-term cycling stability. Here, we demonstrate diffusion-controlled behavior in the intercalation of zinc ions into highly porous, Mn 4+ -rich, and low-band-gap Ni x Mn 3−x O 4 nano-particles with a carbon matrix formed in situ (with the composite denoted as Ni x Mn 3−x O 4 @C, x = 1), which exhibits superior rate capability (139.7 and 98.5 mA h g −1 at 50 and 1200 mA g −1 , respectively) and outstanding cycling stability (128.8 mA h g −1 remaining at 400 mA g −1 after 850 cycles). Based on the obtained experimental results and density functional theory (DFT) calculations, cation-site Ni substitution combined with a sufficient doping concentration can decrease the band gap and effectively improve the electronic conductivity in the crystal. Furthermore, the amorphous carbon shell and highly porous Mn 4+ -rich structure lead to fast electron transport and short Zn 2+ diffusion paths in a mild aqueous electrolyte. This study provides an example of a technique to optimize cathode materials for high-performance rechargeable ZIBs and design advanced intercalation-type materials for other energy storage devices.  more » « less
Award ID(s):
1736093
NSF-PAR ID:
10134955
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
Volume:
7
Issue:
30
ISSN:
2050-7488
Page Range / eLocation ID:
17854 to 17866
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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