Cathode active material layer, all solid lithium battery, and method of manufacturing cathode active material layer

Patent metadata

Field	Value
Publication number	US-2016380266-A1
Application number	US-201615190969-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Jun 29, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A cathode active material layer used for an all solid lithium battery, comprising a flat cathode active material with a hollowness in a range of more than 0% to 10%, and a solid electrolyte material, characterized in that the flat cathode active material has an aspect ratio (long axis length/short axis length) of 1.5 or more in a section in a thickness direction of the cathode active material layer, and a ratio of the flat cathode active material of which the short axis direction corresponds to a thickness direction of the cathode active material layer is 30% or more with respect to the whole cathode active material.

First claim

What is claimed is:

1 . A cathode active material layer for use in an all solid lithium battery, the active material layer comprising:
a flat cathode active material having a hollowness in the range of more than 0% to 10% and an aspect ratio (long axis length/short axis length) of 1.5 or more in a section in a thickness direction of the cathode active material layer; and a solid electrolyte material, wherein a ratio of the flat cathode active material having a short axis direction corresponding to the thickness direction of the cathode active material layer is 30% or more with respect to the whole cathode active material.

2 . The cathode active material layer according to claim 1 , wherein the corresponding signifies an angle of the short axis direction of the flat cathode active material to the thickness direction of the cathode active material is 25° or less.

3 . The cathode active material layer according to claim 1 , wherein the aspect ratio is 3 or less.

4 . The cathode active material layer according to claim 1 , wherein the hollowness is in a range of 1% to 10%.

5 . The cathode active material layer according to claim 1 , wherein a concentration of the flat cathode active material in the cathode active material layer is in a range of 40% to 99% by volume.

6 . The cathode active material layer according to claim 1 , wherein a relative density of the cathode active material layer is in a range of 80% to 100%.

7 . The cathode active material layer according to claim 1 , wherein a thickness of the cathode active material layer is in a range of 0.1 μm to 1000 μm.

8 . An all solid lithium battery comprising:
a cathode active material layer according to claim 1 ; an anode active material layer; and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer.

9 . The all solid lithium battery according to claim 8 , wherein a thickness of the anode active material layer is in a range of 0.1 μm to 1000 μm.

10 . A method of manufacturing a cathode active material layer for use in an all solid lithium battery, the method comprising:
forming a mixture layer containing a hollow cathode active material with a hollowness of 20% or more and a solid electrolyte material; and pressing the mixture layer in a thickness direction to form a flat cathode active material with a hollowness in a range of more than 0% to 10% out of the hollow cathode active material.

11 . The method of manufacturing a cathode active material layer according to claim 10 , wherein the flat cathode active material has an aspect ratio (long axis length/short axis length) of 1.5 or more in a section in a thickness direction of the cathode active material layer, and
a ratio of the flat cathode active material having a short axis direction corresponding to the thickness direction of the cathode active material layer is 30% or more with respect to the whole cathode active material.

12 . The method of manufacturing a cathode active material layer according to claim 10 , wherein the corresponding signifies an angle of the short axis direction of the flat cathode active material to the thickness direction of the cathode active material is 25° or less.

13 . The method of manufacturing a cathode active material layer according to claim 10 , wherein the aspect ratio is 3 or less.

14 . The method of manufacturing a cathode active material layer according to claim 10 , wherein the flat cathode active material is an oxide active material and the solid electrolyte material is a sulfide solid electrolyte material, and
a coat layer containing an Li ion conductive oxide is formed on a surface of the flat cathode active material.

15 . The method of manufacturing a cathode active material layer according to claim 14 , wherein an average thickness of the coat layer is in a range of 0.1 nm to 100 nm.

16 . The method of manufacturing a cathode active material layer according to claim 10 , wherein pressing the mixture layer includes heating the mixture layer.

17 . The method of manufacturing a cathode active material layer according to claim 10 , wherein an average particle diameter (D 50 ) of the hollow cathode active material is in a range of 0.1 μm to 20 μm.

18 . The method of manufacturing a cathode active material layer according to claim 10 , wherein pressing the mixture layer includes flat pressing at a pressure in a range of 800 MPa to 3000 MPa.

19 . The method of manufacturing a cathode active material layer according to claim 10 , wherein pressing the mixture layer includes roll pressing at a pressure in a range of 1.5 ton/cm to 10 ton/cm.

20 . The method of manufacturing a cathode active material layer according to claim 16 , wherein the mixture layer is heated at a temperature in a range of 140° C. to 220° C.

Assignees

• Toyota Motor Co Ltd

Inventors

• Suzuki Tomoya
• Hasegawa Hajime
• Miki Nariaki

Classifications

• H01M50/437

  Glass · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/043

  involving compressing or compaction · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title