title: Facile preparation of core@shell and concentration-gradient spinel particles for Li-ion battery cathode materials.
abstract: Core@shell and concentration-gradient particles have attracted much attention as improved cathodes for Li-ion batteries (LIBs). However, most of their preparation routes have employed a precisely-controlled co-precipitation method. Here, we report a facile preparation route of core@shell and concentration-gradient spinel particles by dry powder processing. The core@shell particles composed of the MnO2core and the Li(Ni,Mn)2O4spinel shell are prepared by mechanical treatment using an attrition-type mill, whereas the concentration-gradient spinel particles with an average composition of LiNi0.32Mn1.68O4are produced by calcination of their core@shell particles as a precursor. The concentration-gradient LiNi0.32Mn1.68O4spinel cathode exhibits the high discharge capacity of 135.3 mA h g-1, the wide-range plateau at a high voltage of 4.7 V and the cyclability with a capacity retention of 99.4% after 20 cycles. Thus, the facile preparation route of the core@shell and concentration-gradient particles may provide a new opportunity for the discovery and investigation of functional materials as well as for the cathode materials for LIBs.
authors.affiliation: Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kozawa
authors.affiliation: Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Makio
authors.initials: M
authors.lastname: Naito
keywords: concentration-gradient; core@shell; lithium-ion battery; mechanical synthesis; spinel cathode