US 12,249,708 B2
Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing the same, positive electrode mixture paste for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
Kazuomi Ryoshi, Niihama (JP); Yoshihiro Otsuka, Niihama (JP); and Hiroko Oshita, Niihama (JP)
Assigned to SUMITOMO METAL MINING CO., LTD., Tokyo (JP)
Appl. No. 16/617,768
Filed by SUMITOMO METAL MINING CO., LTD., Tokyo (JP)
PCT Filed May 31, 2018, PCT No. PCT/JP2018/020988
§ 371(c)(1), (2) Date Apr. 14, 2020,
PCT Pub. No. WO2018/221664, PCT Pub. Date Dec. 6, 2018.
Claims priority of application No. 2017-108035 (JP), filed on May 31, 2017.
Prior Publication US 2020/0251732 A1, Aug. 6, 2020
Int. Cl. H01M 4/525 (2010.01); H01M 4/02 (2006.01); H01M 4/04 (2006.01); H01M 4/131 (2010.01); H01M 4/36 (2006.01); H01M 4/505 (2010.01); H01M 10/0525 (2010.01); H01M 50/46 (2021.01)
CPC H01M 4/525 (2013.01) [H01M 4/0471 (2013.01); H01M 4/131 (2013.01); H01M 4/364 (2013.01); H01M 4/505 (2013.01); H01M 10/0525 (2013.01); H01M 50/46 (2021.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01); H01M 2004/028 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising:
a lithium-nickel composite oxide represented by a general formula: LiaNi1-x-yCoxMyO2+α (where 0.01≤x≤0.35, 0≤y≤ 0.10, 0.95≤a≤ 1.10, and 0≤α≤0.2; and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al); and
a boron compound, wherein
at least part of the boron compound is present on a surface of the lithium-nickel composite oxide in the form of Li3BO3 and LiBO2, and a mass ratio (Li3BO3/LiBO2) between Li3BO3 and LiBO2 is at least 0.005 and up to 10,
boron is contained in an amount of at least 0.011% by mass and up to 0.6% by mass relative to an entire amount of the positive electrode active material, and
only peaks of Li3BO3 and LiBO2 are detected by X-ray diffraction, which are the only peaks other than a peak of lithium nickelate.