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Nitrogen-doped Ti3C2 MXene films with low -F terminal groups achieving an ultrahigh volumetric capacitance
被引:11
|作者:
Luo, Yangyang
[1
,2
]
Jia, Shuting
[1
,2
]
Yi, Yuanjie
[1
,2
]
Liu, Xiong
[1
,2
]
Zhang, Gaini
[1
,2
]
Yang, Huijuan
[1
,2
]
Li, Wenbin
[1
,2
]
Wang, Jingjing
[1
,2
]
Li, Xifei
[1
,2
,3
]
机构:
[1] Xian Univ Technol, Inst Adv Electrochem Energy, Key Lab Adv Batteries Mat Elect Vehicles China Pe, Xian 710048, Peoples R China
[2] Xian Univ Technol, Sch Mat Sci & Engn, Xian 710048, Peoples R China
[3] Fuzhou Univ, Coll Mat Sci Engn, Fuzhou 350108, Fujian, Peoples R China
基金:
中国博士后科学基金;
关键词:
Supercapacitors;
Nitrogen doping;
Film electrode;
Volumetric energy density;
2-DIMENSIONAL NANOMATERIALS;
TITANIUM CARBIDE;
ELECTRODE;
GRAPHENE;
MECHANISM;
D O I:
10.1016/j.jallcom.2023.173355
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
Two-dimensional Ti3C2 MXene with high bulk density can act as prospective electrode material to construct high volumetric energy density supercapacitors. Herein, a series of nitrogen-doped Ti3C2 (N-Ti3C2) films are successfully synthesized by adjusting the quantity of urea using a facile solvothermal method. The incorporation of nitrogen atoms can enlarge interlayer spacing and diminish -F terminal groups of Ti3C2 to promote the diffusion and intercalation of electrolyte ions, and bring about defect sites to provide more electrochemical reactive sites, thus improving the specific capacitance of N-Ti3C2. As a result, the 2.0 N-Ti3C2 film shows the highest volumetric capacitance of 2898.5 F cm-3 at scan rate of 2 mV s-1 in 3 M H2SO4 solution, which is mainly attributed to its high pyridinic N content and low -F terminal groups. Density functional theory (DFT) calculations indicate that the doped N atoms have a higher adsorption energy for protons to enhance the pseudocapacitance of 2.0 N-Ti3C2 electrode, and the increased density of states demonstrate the improvement of its electric conductivity after N doping, which promotes the rate performance of 2.0 N-Ti3C2 electrode. The assembled symmetric supercapacitor based on 2.0 N-Ti3C2 film delivers a high volumetric energy density of 40.8 Wh L-1 and good cycling stability. Our work provides an effective and alternative strategy to improve capacitance of other MXenes for highperformance supercapacitors.
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页数:10
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