A versatile single molecular precursor for the synthesis of layered oxide cathode materials for Li-ion batteries

Abstract

A carbonyl-bridged single molecular precursor LiTM(acac)₃ [transition metal (TM) = cobalt/manganese/nickel (Co/Mn/Ni), acac = acetylacetone], featuring a one-dimensional chain structure, was designed and applied to achieve the layered oxide cathode materials: LiTMO₂ (TM = Ni/Mn/Co, NMC). As examples, layered oxides, primary LiCoO₂, binary LiNi_0.8Co_0.2O₂ and ternary LiNi_0.5Mn_0.3Co_0.2O₂ were successfully prepared to be used as cathode materials. When they are applied to lithium-ion batteries (LIBs), all exhibit good electrochemical performance because of their unique morphology and great uniformity of element distribution. This versatile precursor is predicted to accommodate many other metal cations, such as aluminum (Al³⁺), iron (Fe²⁺), and sodium (Na⁺), because of the flexibility of organic ligand, which not only facilitates the doping-modification of the NMC system, but also enables synthesis of Na-ion layered oxides. This opens a new direction of research for the synthesis of high-performance layered oxide cathode materials for LIBs.