Precursors and methods for preparing Ni-based cathode materials for rechargeable lithium-ion batteries

摘要

A crystalline precursor compound for producing a lithium transition metal-based oxide powder that can be used as a positive electrode active material in a lithium-ion battery, wherein the precursor is a compound represented by the general formula Li1-a ((Niz (Ni1 / 2Mn1 / 2) yCox) 1-kAk) 1 + aO2 (where x + y + z = 1, 0.1 ≦ x ≦ 0.4, 0.25 ≦ z ≦ 0.52, A is a dopant, and 0 ≦ k ≦ 0.1, 0.03 ≦ a ≦ 0.35), the precursor has a crystallite size L expressed in nm, and 15 ≦ L ≦ 36. Precursor compound. LiOH, Li2O and LiOH.6 in an oxidizing atmosphere at a temperature of 800 to 1000 ° C for 6 to 36 hours. Sintering a lithium-deficient precursor powder mixed with any one of H2O has the general formula Li1 + a'M'ia'O2, where M '= (Niz (Ni1 / 2Mn1 / 2 ) YCox) 1-kAk, where x + y + z = 1, 0.1 ≦ x ≦ 0.4, 0.25 ≦ z ≦ 0.52, A is a dopant, 0 ≦ Also described is a method for making a positive electrode material, where k ≦ 0.1 and 0.01 ≦ a ′ ≦ 0.10.