title: Mn-doped TiO2 nanosheet-based spheres as anode materials for lithium-ion batteries with high performance at elevated temperatures.
abstract: Novel Mn(2+)-doped TiO2 nanosheet-based spheres have been successfully prepared via a simple hydrothermal and ion-exchange process. After hydrothermal growth, flowerlike nanosheet-based spheres of protonated dititanate were confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The hierarchical nanostructure was obtained via a dissolution-recrystallization process starting from a precursor of homogenous TiO2 nanospheres. Moreover, as-prepared protonated dititanate was converted to Mn-doped nanosheet-based spheres via the ion-exchange method. Then, both the doped and undoped protonated dititanate were calcined and tested as anode materials for lithium-ion battery applications at elevated temperatures. The undoped sample showed an initial capacity of 201 mAh g(-1) but only had 44.1% of the initial capacity retained after 50 cycles at mixed current densities of 30, 150, and 500 mA g(-1) at 55 °C, while the Mn-doped one exhibited an initial capacity of 190 mAh g(-1) and 91.4% capacity retention with superior reversible capacity under the same test conditions. Comparisons between different samples suggest that manganese ions on the surface of TiO2 nanosheet-based spheres are responsible for the enhanced electrochemical performance.
authors.affiliation: Kazuo Inamori School of Engineering, the New York State College of Ceramics, Alfred University , Alfred, New York 14802, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhou
authors.forename: Jasper H
authors.initials: JH
authors.lastname: Wright
authors.forename: Young Nam
authors.initials: YN
authors.lastname: Kim
authors.forename: Dawei
authors.initials: D
authors.lastname: Liu
authors.forename: Xingcheng
authors.initials: X
authors.lastname: Xiao