Lithium composite metal oxide, positive electrode active substance, positive electrode, and non-aqueous electrolyte secondary battery

Abstract

A lithium composite metal oxide that contains Li, Ni, and Mn, has a layered structure, has a diffraction peak in a range of 2θ=20.8±1° in a powder X-ray diffraction pattern obtained with powder X-ray diffraction measurement using a Cu-Kα radiation, has a BET specific surface area in a range of 6 m 2 /g to 30 m 2 /g, and has an average particle diameter measured with a laser diffraction scattering method in a range of 0.1 μm to 10 μm.

1 . A lithium composite metal oxide which contains Li, Ni, and Mn,
 has a lamellar structure,   has a diffraction peak in a range of 2θ=20.8±1° in a powder X-ray diffraction pattern obtained through powder X-ray diffraction measurement using a Cu-Kα radiation,   has a BET specific surface area of from 6 m 2 /g to 30 m 2 /g, and   has an average particle diameter measured by a laser diffraction scattering method of from 0.1 μm to 10 μm,   wherein the lithium composite metal oxide is represen ted by Formula (A) described below
   Li a Ni 1-x-y Mn x M y O 2    (A) ,
 
   wherein 1.1≦a≦1.6, 0.4≦x≦0.8, 0≦y≦0.25, 0.5≦x+y≦0.8, and M represents one or more elements selected from the group consisting of Co, Fe, Mg, Al, and Ca.   
     
     
         2 . The lithium composite metal oxide according to  claim 1 ,
 wherein an average primary particle diameter of the lithium composite metal oxide is from 0.05 μm to 0.3 μm.   
     
     
         3 . The lithium composite metal oxide according to  claim 3 ,
 wherein M represents one or more elements selected from the group consisting of Co and Fe.   
     
     
         4 . A positive electrode active material comprising:
 the lithium composite metal oxide according to  Claim 1 .   
     
     
         5 . A positive electrode comprising:
 the positive electrode active substance according to  claim 6 .   
     
     
         6 . A non-aqueous electrolyte secondary battery comprising:
 a negative electrode and the positive electrode according to  claim 7 .   
     
     
         7 . The non-aqueous electrolyte secondary battery according to claim  8 ,
 wherein a charge potential of the positive electrode in a fully charged state is 4.35 V (vs. Li/Li + ) or more.