Core鈥揝hell Ellipsoidal MnCo2O4 Anode with Micro-/Nano-Structure and Concentration Gradient for Lithium-Ion Batteries

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• 作者：Guoyong Huang ; Shengming Xu ; Zhenghe Xu ; Hongyu Sun ; Linyan Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：December 10, 2014
• 年：2014
• 卷：6
• 期：23
• 页码：21325-21334
• 全文大小：713K
• ISSN：1944-8252

文摘

In this study, novel core鈥搒hell ellipsoidal MnCo₂O₄ powders with desired micro/nano-structure and a unique concentration gradient have been synthesized as anode material for Li-ion batteries. The special porous ellipsoid (2.5鈥?.5 渭m in the long axis, 1.5鈥?.5 渭m in the short axis, 200鈥?00 nm in the thickness of shell) is built up by irregular nanoparticles attached to each other, and corresponding to the ellipsoid with concentration gradient, the Co/Mn atomic ratios of core and shell are about 1.76:1 and 2.34:1, respectively. The good performance, including high initial discharge capacities (1433.3 mAhg^鈥? at 0.1 Ag^鈥? and 1248.4 mAhg^鈥? at 0.4 Ag^鈥?), advanced capacity retention (鈭?00.0 mAhg^鈥? after 60 cycles at 0.1 Ag^鈥?), and fair rate performance (鈭?20.0 mAhg^鈥? after 50 cycles at 0.4 Ag^鈥?) has been measured by the battery test. Remarkably, the ellipsoidal shape and core鈥搒hell microstructure with concentration gradient are still maintained after 70 cycles of charge/discharge at 0.1 Ag^鈥?.

Keywords:

MnCo₂O₄; core鈭抯hell; ellipsoidal; micro/nano-structure; concentration gradient; electrochemistry