共 28 条
Hydrous manganese dioxide nanowall arrays growth and their Li+ ions intercalation electrochemical properties
被引:123
作者:
Liu, Dawei
[1
]
Zhang, Qifeng
[1
]
Xiao, Peng
[1
,4
]
Garcia, Betzaida B.
[1
]
Guo, Qing
[2
]
Champion, Richard
[3
]
Cao, Guozhong
[1
]
机构:
[1] Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA
[2] Univ Washington, Dept Mech Engn, Seattle, WA 98195 USA
[3] Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA
[4] Chongqing Univ, Dept Phys, Chongqing, Peoples R China
关键词:
D O I:
10.1021/cm702033z
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:
Nanowall arrays of hydrous manganese dioxide MnO2 center dot 0.5H(2)O were deposited on cathodic substrates by the potentiostatic method from a mixed aqueous solution of manganese acetate and sodium sulfate, and the Li+ ions intercalation properties of such nanowall arrays were studied. The deposition was induced by a change of local pH resulting from electrolysis of H2O. Composition of this new nanowall structure was investigated by means of combined XRD, XPS, and TGA and determined to be hydrous manganese dioxide. SEM study revealed that the MnO2 center dot 0.5H(2)O nanowall arrays were homogeneous across the entire substrate of top thicknesses that varied from 50 to 100 nm with identical depth. The nanowall arrays of hydrous manganese dioxide exhibited an initial capacity of 270 mAh/g with a reversible capacity maintained at 220 mAh/g at the 50th charge/discharge cycle in the Li+ ions intercalation capacity measurement at a high charge/discharge rate of 0.1 mA/cm(2) (C/2, 76 mAh/g). This greatly enhanced Li+ ions intercalation capacity is ascribed to the large active surface area of the nanowall arrays and a short facile diffusion path for Li+ ions. The nanowall arrays of hydrous manganese dioxide also displayed an improved cyclic stability attributed to the reduced strain accumulated in these nanostructures during Li+ ions intercalation.
引用
收藏
页码:1376 / 1380
页数:5
相关论文