Method for preparing positive electrode active material for non-aqueous secondary battery

Abstract

There is provided a simple and easy method of preparation of a positive electrode active material for a non-aqueous secondary battery which comprises a compound comprising lithium, nickel and manganese and having a layered structure. Said method comprises firing a mixture of (1) at least one member selected from the group consisting of dinickel trioxide and boron compounds and (2) one or more metal compounds comprising lithium, nickel and manganese as their metal elements.

1. A method for preparing a positive electrode active material for a non-aqueous secondary battery comprising a step of firing a mixture of (1) at least one member selected from the group consisting of dinickel trioxide and boron compounds and (2) one or more metal compounds comprising lithium, nickel and manganese as their metal elements and a step of obtaining a compound comprising lithium, nickel and manganese and having a layered structure, wherein the compound comprising lithium, nickel and manganese and having a layered structure is a compound which is identified in X-ray diffraction as a compound represented by the composition formula Li[Ni (x-y) Li (1/3-2x/3) Mn (2/3-x/3-y) Co 2y ]O 2 , wherein 0<x≦0.5, 0≦y≦⅙ and x>y, and having a layered structure. 
     
     
       2. A positive electrode active material for a non-aqueous secondary battery obtained by the method of preparation according to  claim 1 . 
     
     
       3. A positive electrode active material for a non-aqueous secondary battery comprising a compound which comprises lithium, nickel, manganese and cobalt and being represented by the composition formula Li[Ni 0.34 Li 0.04 Mn 0.42 Co 0.02 ]O 2  or Li[Ni 0.31 Li 0.06 Mn 0.43 Co 0.02 ]O 2  and having a layered structure identified in X-ray diffraction. 
     
     
       4. A non-aqueous secondary battery obtained by using the positive electrode active material for a non-aqueous secondary battery according to  claim 2 . 
     
     
       5. A non-aqueous secondary battery obtained by using the positive electrode active material for a non-aqueous secondary battery according to  claim 3 . 
     
     
       6. A method of preparing a positive electrode active material for a non-aqueous secondary battery comprising a step of firing a mixture of (1) at least one member selected from the group consisting of dinickel trioxide and boron compounds and (2) one or more metal compounds selected from the group consisting of a lithium compound, a nickel compound and a manganese compound and a step of obtaining a compound comprising lithium, nickel and manganese and having a layered structure, wherein the compound comprising lithium, nickel and manganese and having a layered structure is a compound which is identified in X-ray diffraction as a compound represented by the composition formula Li[Ni (x-y) Li (1/3-2x/3) Mn (2/3-x/3-y) Co 2y ]O 2 , wherein 0<x≦0.5, 0≦y≦⅙ and x>y, and having a layered structure.  
     
     
       7. A positive electrode active material for a non-aqueous secondary battery obtained by the method of preparation according to claim 6.  
     
     
       8. A non-aqueous secondary battery obtained by using the positive electrode active material for a non-aqueous secondary battery according to claim 7.  
     
     
       9. A method of preparing a positive electrode active material for a non-aqueous secondary battery comprising a step of firing a mixture of (1) at least one member selected from the group consisting of dinickel trioxide and boron compounds and (2) a lithium compound, a nickel compound, a manganese compound and optionally a cobalt compound and a step of obtaining a compound comprising lithium, nickel and manganese and having a layered structure, wherein the compound comprising lithium, nickel and manganese and having a layered structure is a compound which is identified in X-ray diffraction as a compound represented by the composition formula Li[Ni (x-y) Li (1/3-2x/3) Mn (2/3-x/3-y) Co 2y ]O 2 , wherein 0<x≦0.5, 0≦y≦⅙ and x>y, and having a layered structure.  
     
     
       10. A positive electrode active material for a non-aqueous secondary battery obtained by the method of preparation according to claim 9.  
     
     
       11. A non-aqueous secondary battery obtained by using the positive electrode active material for a non-aqueous secondary battery according to claim 10.