Suppressing Manganese Dissolution via Exposing Stable {111} Facets for High-Performance Lithium-Ion Oxide Cathode.

Spinel-type LiMnO cathode materials commonly suffer from manganese dissolution due to the severe interfacial side reactions especially at elevated temperature. Here, a 3D hollow fusiform LiMnO cathode material is reported with preferentially exposed stable {111} facets and seamless outer structure, which is clearly confirmed by microfocused ion beam scanning electron microscopy, high-resolution transmission electron microscopy as well as scanning transmission electron microscopy with atomic resolution. Owing to the optimal geometrical structure design and the preferentially exposed stable {111} facets, the electrode delivers excellent rate capability (107.6 mAh g at 10 C), remarkable cycling stability (83.3% capacity retention after 1000 cycles at 1 C), and outstanding high-temperature performance. Together with the analyses of electrochemical behaviors, in situ X-ray diffraction at different temperatures, and ex situ X-ray photoelectron spectra, the underlying working mechanism for suppressing manganese dissolution is clearly articulated. These findings could provide significant guidelines for precisely designing highly stable cathode materials for LIBs.