Non-aqueous electrolyte secondary battery and method of fabricating same

Patent metadata

Field	Value
Publication number	US-9831525-B2
Application number	US-201214397292-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	Apr 27, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

The present invention provides a non-aqueous electrode secondary battery supplied with a non-aqueous electrolyte comprising an overcharge additive. The positive electrode material layer constituting the positive electrode in the non-aqueous electrolyte secondary battery is characterized by having a differential pore volume peak A as well as a peak B located on the smaller pore diameter side than the peak A in a pore diameter range of 0.05 μm to 2 μm in a pore size distribution curve measured by a mercury porosimeter, wherein the pore size distribution curve has a minimum C corresponding to a minimum differential pore volume between the peak A and the peak B, such that a ratio (X C /X L ) of the minimum C's differential pore volume X C to a differential pore volume X L , which is the larger between the peak A's differential pore volume X A and the peak B's differential pore volume X B is 0.6 or larger.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode having a positive electrode material layer; and
a non-aqueous electrolyte comprising an overcharge additive,
wherein the positive electrode material layer has two differential pore volume peaks A and B in a pore diameter range of 0.05 μm to 2 μm in a pore size distribution curve measured by a mercury porosimeter, the peak B located on a smaller pore diameter side than the peak A in the pore size distribution curve,
the pore size distribution curve has a minimum C corresponding to a minimum differential pore volume value between the differential pore volume peaks A and B, and
a ratio (X C /X L ) of a differential pore volume X C of the minimum C to a differential pore volume X L is 0.6 or larger, the differential pore volume X L being the larger differential pore volume between a differential pore volume X A of the differential pore volume peak A and a differential pore volume X B of the differential pore volume peak B.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the differential pore volume peak A is present in a pore diameter range of 0.2 μm to 2 μm and the differential pore volume peak B is present in a pore diameter range of 0.05 μm to 0.5 μm in the pore size distribution curve.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein a ratio (X B /X A ) of the differential pore volume X B of the differential pore volume peak B to the differential pore volume X A of the differential pore volume peak A is 0.8 or larger, but 1.25 or smaller.

4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode material layer satisfies Y L <Y S wherein Y L is a cumulative pore volume over a pore diameter range larger than a pore diameter P C of the minimum C and Y S is a cumulative pore volume over a pore diameter range smaller than the pore diameter P C .

5. The non-aqueous electrolyte secondary battery according to claim 1 , comprising a negative electrode and a separator placed between the positive electrode and the negative electrode,
wherein a ratio (α/β) of a Gurley permeability α of the positive material layer to a Gurley permeability β of the separator satisfies 0.5<α/β<1.

6. The non-aqueous electrolyte secondary battery according to claim 1 , comprising a battery case and a current interrupt device that interrupts a conduction pathway when a prescribed internal pressure value is reached inside the battery case.

7. A method for producing a non-aqueous electrolyte secondary battery, the method comprising the steps of:
obtaining a positive electrode and a negative electrode, the positive electrode comprising a positive electrode material layer;
constructing an electrode body with the positive electrode and the negative electrode obtained; and
supplying the electrode body with a non-aqueous electrolyte comprising an overcharge additive,
wherein the method further comprises selecting and using the positive electrode material layer, which satisfies the following properties:
(a) the positive electrode material layer has two differential pore volume peaks A and B in a pore diameter range of 0.05 μm to 2 μm in a pore size distribution curve measured by a mercury porosimeter, the differential pore volume peak B located on a smaller pore diameter side than the differential pore volume peak A in the pore size distribution curve,
(b) the pore size distribution curve has a minimum C corresponding to a minimum differential pore volume value between the differential pore volume peaks A and B, and
(c) a ratio (X C /X L ) of a differential pore volume X C of the minimum C to a differential pore volume X L is 0.6 or larger, the differential pore volume X L being the larger differential pore volume between a differential pore volume X A of the differential pore volume peak A and a differential pore volume X B of the differential pore volume peak B.

8. The method according to claim 7 , wherein the positive electrode material layer further satisfies the following property:
(d) the differential pore volume peak A is present in a pore diameter range of 0.2 μm to 2 μm and the differential pore volume peak B is present in a pore diameter range of 0.05 μm to 0.5 μm in the pore size distribution curve.

9. The method according to claim 7 , wherein the positive electrode material layer further satisfies the following property:
(e) a ratio (X B /X A ) of the differential pore volume X B of the differential pore volume peak B to the differential pore volume X A of the differential pore volume peak A is 0.8 or larger, but 1.25 or smaller.

10. The method according to claim 7 , wherein the positive electrode material layer further satisfies the following property:
(f) Y L <Y S wherein Y L is a cumulative pore volume over a pore diameter range larger than a pore diameter P C of the minimum C and Y S is a cumulative pore volume over a pore diameter range smaller than the pore diameter P C .

11. The method according to claim 7 , comprising constructing a current interrupt device that interrupts a conduction pathway when a prescribed internal pressure value is reached inside its battery case.

12. A vehicle comprising the non-aqueous electrolyte secondary battery according to claim 1 .

Assignees

• Morita Masahiro
• Oyama Yutaka
• Tsubouchi Takahiro
• Saito Atsushi
• Okada Yukihiro
• Toyota Motor Co Ltd

Inventors

• Morita Masahiro
• Oyama Yutaka
• Tsubouchi Takahiro
• Saito Atsushi
• Okada Yukihiro

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title