Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2021167378-A1
Application number	US-201917059306-A
Country	US
Kind code	A1
Filing date	May 29, 2019
Priority date	May 31, 2018
Publication date	Jun 3, 2021
Grant date	—

Abstract

The present invention relates to a positive electrode active material for non-aqueous electrolyte secondary battery, including lithium-nickel composite oxide particles having a layer structure of hexagonal system; and a lithium tungstate coating film disposed on a surface of secondary particles of the lithium-nickel composite oxide particles, wherein the positive electrode active material for non-aqueous electrolyte secondary battery includes, as metallic elements, lithium (Li), nickel (Ni), cobalt (Co), element M (M) which is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, Ca, Cr, Zr, Ta, and Al, and tungsten (W), wherein a ratio of amount of substance in the metallic elements contained is Li:Ni:Co:M:W=a: 1 -x-y:x:y:z, wherein 0.97≤a≤1.25, 0≤x≤0.35, 0≤y≤0.35, and 0.005≤z≤0.030.

First claim

1 . A positive electrode active material for non-aqueous electrolyte secondary battery, comprising:
lithium-nickel composite oxide particles having a layer structure of hexagonal system; and a lithium tungstate coating film disposed on a surface of secondary particles of the lithium-nickel composite oxide particles, wherein the positive electrode active material for non-aqueous electrolyte secondary battery includes, as metallic elements, lithium (Li), nickel (Ni), cobalt (Co), element M (M) which is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, Ca, Cr, Zr, Ta, and Al, and tungsten (W), wherein a ratio of amount of substance in the metallic elements contained is Li:Ni:Co:M:W=a:1-x-y:x:y:z, wherein 0.97≤a≤1.25, 0≤x≤0.35, 0≤y≤0.35, and 0.005≤z≤0.030, and wherein a ratio of a maximum tungsten concentration to an average tungsten concentration is 5 or more and 25 or less when a line analysis is performed by STEM-EDX on a particle cross-section of the positive electrode active material for non-aqueous electrolyte secondary battery.

2 . The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 , wherein a crystalline phase of the lithium tungstate on the surface of the secondary particles is at least one selected from 7Li 2 WO 4 .4H 2 O, Li 2 WO 4 , and Li 4 WO 5 .

3 . The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 ,
wherein a specific surface area as measured by a BET method is 0.2 m 2 /g or more and 0.8 m 2 /g or less.

4 . The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 ,
wherein a volume resistivity when compressed to 3.2 g/cc as determined by a powder resistivity measurement is 1.0×10 2 Ω·cm or more and 1.0×10 4 Ω·cm or less.

5 . The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 ,
wherein a volume average particle size Mv is 5 μm or more and 20 μm or less.

6 . A non-aqueous electrolyte secondary battery comprising:
the positive electrode active material for non-aqueous electrolyte secondary battery of claim 1 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Koshika Yuki
• KANEDA Haruki
• Yokoyama Jun

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/366

  as layered products · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title