Lithium secondary battery and positive electrode active material for the lithium secondary battery

Patent metadata

Field	Value
Publication number	US-9887430-B2
Application number	US-201013635742-A
Country	US
Kind code	B2
Filing date	Mar 19, 2010
Priority date	Mar 19, 2010
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

The present invention provides a lithium secondary battery having a positive electrode provided with a positive electrode active material formed of a lithium-manganese complex oxide represented by the general formula

Li x (Mn a Co b Ni c ) 2−x−y M y O 2   (1)

(where, a, b, and c are 0<a<0.65, 0≦b, and 0≦c, and x and y are 0<x<1.3 and 0<y<0.05), with the element M being an element that has a larger bond energy with oxygen than Mn, Co, or Ni.

First claim

The invention claimed is:

1. A lithium secondary battery comprising a positive electrode provided with a positive electrode active material formed of a lithium-manganese complex oxide represented by the general formula
Li x (Mn a Co b Ni c ) 2−x−y M y O 2   (1)

where, a, b, and c are 0.5<a<0.65, 0<b, 0≦c(2−x−y)≦0.13, and a+b+c=1, and x and y are 1<x≦1.2 and 0.001<y<0.03, with the element M being Ca, wherein
the lithium-manganese complex oxide consists of Li, Mn, Co, Ni, M and O,
the lithium-manganese complex oxide is the only positive electrode active material of the lithium secondary battery, and
an X-ray diffraction pattern measured by a powder diffractometer (XRD) has a peak attributable to an Mn-containing compound recognized at a position for 2θ in the vicinity of 22°.

2. A method of producing a positive electrode comprising a positive electrode active material formed of a lithium-manganese complex oxide,
this production method comprising the following steps:
a step of preparing a starting material mixture by mixing, in an aqueous solvent, an organic acid and starting materials for forming a lithium-manganese complex oxide represented by the general formula
Li x (Mn a Co b Ni c ) 2−x−y M y O 2   (1)

where, a, b, and c are 0.5<a<0.65, 0<b, 0≦c(2−x−y)≦0.13, and a+b+c=1, and x and y are 1<x≦1.2 and 0.001<y<0.03, with the element M being Ca;
a step of heating the starting material mixture and drying off the aqueous solvent;
a step of pre-calcining the starting material mixture after the aqueous solvent has been dried off;
a step of grinding the pre-calcined material and calcining the same at a temperature higher than the pre-calcination temperature; and
a step of forming the positive electrode comprising the positive electrode active material, wherein
the lithium-manganese complex oxide consists of Li, Mn, Co, Ni, M and O,
the lithium-manganese complex oxide is the only positive electrode active material of a lithium secondary battery including a positive electrode provided with the positive electrode active material, and
an X-ray diffraction pattern measured by a powder diffractometer (XRD) has a peak attributable to an Mn-containing compound recognized at a position for 2θ in the vicinity of 22°.

3. The production method according to claim 2 , wherein the pre-calcination in the pre-calcination step is carried out at 400 to 600° C.

4. The production method according to claim 3 , wherein calcination is carried out in the calcination step at a temperature above the pre-calcination temperature but at most 1000° C.

5. The production method according to claim 4 , wherein the average particle size (median size) of the calcined material obtained after implementing the calcination step is 1 μm to 10 μm based on measurement of the particle size distribution by laser diffraction.

6. The production method according to claim 4 , wherein the BET specific surface area of the calcined material obtained after implementing the calcination step is at least 2 m 2 /g.

7. A vehicle comprising the lithium secondary battery according to claim 1 .

Assignees

• Terashima Junpei
• Toyota Motor Co Ltd

Inventors

• Terashima Junpei

Classifications

• C01P2006/12

  Surface area · CPC title

• C01P2004/61

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

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title