Positive electrode active material for non-aqueous electrolyte secondary battery and method for producing same

Patent metadata

Field	Value
Publication number	US-2020020941-A1
Application number	US-201916577022-A
Country	US
Kind code	A1
Filing date	Sep 20, 2019
Priority date	Mar 31, 2017
Publication date	Jan 16, 2020
Grant date	—

Abstract

This cathode active material for a secondary battery using a non-aqueous electrolyte includes nickel-rich lithium transition-metal oxide, exhibits a hard X-ray photoelectron spectroscopy (HAXPES) peak of 1,560 to 1,565 eV in binding energy from an Al-rich layer, using a photon energy of 6 KeV, and with respect to the mean particle diameter r of the lithium transition-metal oxide particle, the Al concentration is approximately constant within 0.35 r of the center.

First claim

1 . A positive electrode active material for a non-aqueous electrolyte secondary battery, including a nickel-containing lithium transition metal oxide represented by a formula (1), wherein
a peak of 1560 to 1565 eV in binding energy from an Al-rich layer exists in hard X-ray photoelectron spectroscopy (HAXPES) at a photon energy of 6 KeV, and when lithium transition metal oxide particles have an average particle diameter of r, an Al concentration is approximately constant within a range of 0.35r from the center:
Li x Ni a Co b Al c M d O 2   (Formula 1),

wherein x, a, b, c, and d meet 0.95<x<1.05, 0.91≤a<1, 0<b<0.15, 0≤d<0.15, and 0.03<c, and M represents at least one metal element selected from the group consisting of B, Si, Mg, Ge, Sn, Mg, Cr, Mn, Ti, Nb, Mo, and Fe.

2 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the Al-rich layer contains LiAlO 2 .

3 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the Al concentration of the lithium transition metal oxide particles meets 0.99<(Al concentration at 0.35r)/(Al concentration at central portion)<1.01.

4 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the Al-rich layer is a mixed body of LiAlO 2 and an oxide containing Li, Ni, Co, and Al.

5 . A method for producing a positive electrode active material for a non-aqueous secondary battery, the positive electrode active material including a nickel-containing lithium transition metal oxide, the method including the steps of:
mixing a nickel cobalt aluminum-containing oxide carrying lithium hydroxide or lithium carbonate on a surface thereof with an Al compound; and heating the nickel cobalt aluminum-containing oxide and the Al compound at 500° C. to 800° C.

6 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the Al-rich layer has a thickness of 300 nm or less.

7 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the Al-rich layer has a thickness of 100 nm or less.

Assignees

• Panasonic Corp
• Sanyo Electric Co

Inventors

• MIZAWA Miki
• Nagata Kaoru
• Maekawa Masanori
• Kinoshita Masahiro

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• C01P2002/52

  containing elements as dopants · CPC title

• C01P2002/54

  one element only · CPC title