Positive electrode and nonaqueous electrolyte battery

Patent metadata

Field	Value
Publication number	US-9711782-B2
Application number	US-201514645867-A
Country	US
Kind code	B2
Filing date	Mar 12, 2015
Priority date	Aug 25, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

According to one embodiment, there is provided a positive electrode including a positive electrode active material-including layer including a positive electrode active material, which includes a lithium-manganese oxide LiMn 2-x M x O 4 , and a conductive agent. In the positive electrode active material-including layer, an average particle diameter d 50 is within 2 μm to 5 μm, a particle diameter d 10 and a particle diameter d 90 , where a cumulative frequency from a smaller side is, respectively, 10% and 90%, is within 0.5 μm to 3 μm and within 4 μm to 10 μm, respectively, in a particle size distribution. X, represented by X=(d 50 −d 10 ) /d 50 is within 0.4 to 0.8. Y, represented by Y=(d 90 −d 50 )/d 90 is within 0.2 to 0.6.

First claim

What is claimed is:

1. A positive electrode comprising:
a positive electrode current collector; and
a positive electrode active material-including layer formed on the positive electrode current collector;
wherein, the positive electrode active material-including layer includes a positive electrode active material and a conductive agent, the positive electrode active material includes a lithium-manganese oxide represented by LiMn 2-x M x O 4 , in which subscript x is within a range of 0.22≦x≦0.7, and M is at least one metal element selected from a group consisting of Mg, Ti, Cr, Fe, Co, Zn, Al, and Ga, and in a particle size distribution of the positive electrode active material-including layer obtained by a laser diffraction scattering method, an average particle diameter d 50 is within a range of 2 μm to 5 μm, a particle diameter d 10 at which a cumulative frequency from a small particle diameter side is 10% is within a range of 0.5 μm to 3 μm, and a particle diameter d 90 at which a cumulative frequency from the small particle diameter side is 90% is within a range of 4 μm to 10 μm, X, represented by X=(d 50 −d 10 )/d 50 , is within a range of 0.4 to 0.8, and Y, represented by Y=(d 90 −d 50 )/d 90 , is within a range of 0.2 to 0.6.

2. The positive electrode according to claim 1 , wherein
the metal element M includes Al.

3. The positive electrode according to claim 2 , wherein
in a pore size distribution of the positive electrode active material-including layer obtained by a mercury intrusion method, a median diameter D me is within a range of 0.15 μm to less than 0.4 μm, and a mode diameter D mo is within a range of 0.15 μm to less than 0.4 μm.

4. The positive electrode according to claim 2 , wherein
the positive electrode active material-including layer has a density of 2.8 g/cm 2 to less than 3.5 g/cm 2 .

5. The positive electrode according to claim 1 , wherein
an amount of the positive electrode active material included in the positive electrode active material-including layer is 91% to less than 96% relative to a weight of the positive electrode active material-including layer.

6. A nonaqueous electrolyte battery comprising:
the positive electrode according to claim 1 ;
a negative electrode; and
a nonaqueous electrolyte.

7. The nonaqueous electrolyte battery according to claim 6 , wherein
the negative electrode includes an oxide of titanium.

8. The nonaqueous electrolyte battery according to claim 7 , wherein
the oxide of titanium includes lithium titanate Li 4 Ti 5 O 12 .

9. A positive electrode comprising:
a positive electrode current collector; and
a positive electrode active material-including layer formed on the positive electrode current collector,
wherein, the positive electrode active material-including layer includes positive electrode active material particles and conductive agent particles, the positive electrode active material particles including a lithium-manganese oxide represented by LiMn 2-x M x O 4 , in which subscript x is within a range of 0.22≦x≦0.7, and M is at least one metal element selected from a group consisting of Mg, Ti, Cr, Fe, Co, Zn, Al, and Ga, and in a particle size distribution of particles in the positive electrode active material-including layer obtained by a laser diffraction scattering method, an average particle diameter d 50 is within a range of 2 μm to 5 μm, a particle diameter d 10 at which a cumulative frequency from a small particle diameter side is 10% is within a range of 0.5 μm to 3 μm, and a particle diameter d 90 at which a cumulative frequency from the small particle diameter side is 90% is within a range of 4 μm to 10 μm, X, represented by X=(d 50 −d 10 )/d 50 , is within a range of 0.4 to 0.8, and Y, represented by Y=(d 90 −d 50 )/d 90 , is within a range of 0.2 to 0.6.

10. The positive electrode according to claim 9 , wherein
an amount of the positive electrode active material particles included in the positive electrode active material-including layer is 91% to less than 96% relative to a weight of the positive electrode active material-including layer.

Assignees

• Toshiba Kk

Inventors

• Yoshikawa Hikaru
• Kuriyama Hiromichi
• Murashi Yasuaki
• Saruwatari Hidesato
• Yamamoto Dai

Classifications

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• C01G51/54

  of the type (Mn2O4)-, e.g. Li(CoxMn2-x)O4 or Li(MyCoxMn2-x-y)O4 · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/131 Primary

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