In situ nano-coating on Li sub(1.2)Mn sub(0.52)Ni sub(0.13)Co sub(0.13)O sub(2) with a layered spinel coating layer heterostructure for lithium-ion batteries

Lithium-rich manganese-based layered oxides with a composition of xLi sub(2)MnO sub(3).(1 - x)LiMO sub(2) (M = Mn, Co, Ni, etc.) are attractive, due to their high discharge capacity. However, the concerns over Li sub(2)MnO sub(3)-LiMO sub(2) composite cathodes such as high irreversible capacity and poor rate performance remain to be the main obstacles to commercialization. Here we introduce a thin chromium oxide layer and a spinel metal oxide layer to doubly coat on the surface of Li sub(1.2)Mn sub(0.52)Ni sub(0.13)Co sub(0.13)O sub(2) (LMNCO) by a spray drying process as well as an inducer of the layered spinel coating layer heterostructure to achieve better electrochemical performance. X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM) results confirm the successful formation of a chromium oxide layer on the surface of LMNCO without destroying its intrinsic structure. The reduced irreversible capacity loss and improved cycling stability are ascribed to the coating layer and the heterostructure. Furthermore, fast voltage fading of the solid solutions of layered transition metal oxides is also alleviated.