title: Core-shell ellipsoidal MnCo₂O₄ anode with micro-/nano-structure and concentration gradient for lithium-ion batteries.
abstract: In this study, novel core-shell 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 (2.5-4.5 μm in the long axis, 1.5-2.5 μm in the short axis, 200-300 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(-1) at 0.1 Ag(-1) and 1248.4 mAhg(-1) at 0.4 Ag(-1)), advanced capacity retention (∼900.0 mAhg(-1) after 60 cycles at 0.1 Ag(-1)), and fair rate performance (∼620.0 mAhg(-1) after 50 cycles at 0.4 Ag(-1)) has been measured by the battery test. Remarkably, the ellipsoidal shape and core-shell microstructure with concentration gradient are still maintained after 70 cycles of charge/discharge at 0.1 Ag(-1).
authors.affiliation: Institute of Nuclear and New Energy Technology, Tsinghua University , Beijing 100084, China.
authors.forename: Guoyong
authors.initials: G
authors.lastname: Huang
authors.forename: Shengming
authors.initials: S
authors.lastname: Xu
authors.forename: Zhenghe
authors.initials: Z
authors.lastname: Xu
authors.forename: Hongyu
authors.initials: H
authors.lastname: Sun
authors.forename: Linyan
authors.initials: L
authors.lastname: Li
keywords: MnCo2O4; concentration gradient; core−shell; electrochemistry; ellipsoidal; micro/nano-structure