title: Hierarchical surface atomic structure of a manganese-based spinel cathode for lithium-ion batteries.
abstract: The increasing use of lithium-ion batteries (LIBs) in high-power applications requires improvement of their high-temperature electrochemical performance, including their cyclability and rate capability. Spinel lithium manganese oxide (LiMn2O4) is a promising cathode material because of its high stability and abundance. However, it exhibits poor cycling performance at high temperatures owing to Mn dissolution. Herein we show that when stoichiometric lithium manganese oxide is coated with highly doped spinels, the resulting epitaxial coating has a hierarchical atomic structure consisting of cubic-spinel, tetragonal-spinel, and layered structures, and no interfacial phase is formed. In a practical application of the coating to doped spinel, the material retained 90% of its capacity after 800 cycles at 60 °C. Thus, the formation of an epitaxial coating with a hierarchical atomic structure could enhance the electrochemical performance of LIB cathode materials while preventing large losses in capacity.
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 689-798, Ulsan (Republic of Korea).
authors.forename: Sanghan
authors.initials: S
authors.lastname: Lee
authors.forename: Gabin
authors.initials: G
authors.lastname: Yoon
authors.forename: Minseul
authors.initials: M
authors.lastname: Jeong
authors.forename: Min-Joon
authors.initials: MJ
authors.lastname: Lee
authors.forename: Kisuk
authors.initials: K
authors.lastname: Kang
authors.forename: Jaephil
authors.initials: J
authors.lastname: Cho
keywords: cathodes; epitaxial coating; hierarchical atomic structures; lithium manganese oxide; lithium-ion batteries