All-solid secondary battery

Patent metadata

Field	Value
Publication number	US-2019190064-A1
Application number	US-201816143620-A
Country	US
Kind code	A1
Filing date	Sep 27, 2018
Priority date	Dec 18, 2017
Publication date	Jun 20, 2019
Grant date	—

Abstract

An all-solid secondary battery, comprising: a cell comprising a positive electrode active material layer, a negative electrode active material comprising at least one of lithium metal and a lithium-containing alloy, and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, wherein a ratio of volume density to true density of the positive electrode active material layer is about 0.6 or greater, wherein a ratio of volume density to true density of the solid electrolyte layer is about 0.6 or greater, and wherein an average pressure applied to opposite sides of the solid electrolyte layer in a fully discharged state is greater than 0 megapascals and 7.5 megapascals or less.

First claim

What is claimed is:

1 . An all-solid secondary battery, comprising:
a cell comprising a positive electrode active material layer, a negative electrode active material layer comprising at least one of lithium metal and a lithium-containing alloy, and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, wherein a ratio of volume density to true density of the positive electrode active material layer is about 0.6 or greater, wherein a ratio of volume density to true density of the solid electrolyte layer is about 0.6 or greater, wherein an average pressure applied to opposite sides of the cell in a fully discharged state is greater than 0 megapascals and 7.5 megapascals or less,
wherein a ratio of a standard deviation of a pressure distribution of the pressure applied to the opposite sides of the cell to the average pressure applied to the opposite sides of the cell in the fully discharged state is about 0.35 or less.

2 . The all-solid secondary battery of claim 1 ,
wherein the ratio of the standard deviation of the pressure distribution to the average pressure applied is about 0.15 to about 0.25.

3 . The all-solid secondary battery of claim 1 ,
wherein the average pressure is about 0.5 megapascal to about 6 megapascals.

4 . The all-solid secondary battery of claim 1 ,
wherein the positive electrode active material layer comprises a positive electrode active material and a solid electrolyte.

5 . The all-solid secondary battery of claim 4 ,
wherein the positive electrode active material layer comprises a lithium transition metal oxide comprising a layered rock-salt-type structure.

6 . The all-solid secondary battery of claim 5 ,
wherein the positive electrode active material layer comprises a compound represented by the formula
LiNi x Co y Al z O 2 ,
wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1, or by the formula
LiNi x Co y Mn z′ O 2
wherein 0<x′<1, 0<y′<1, 0<z′<1, and x′+y′+z′=1.

7 . The all-solid secondary battery of claim 1 ,
wherein the positive electrode active material layer further comprises a binder.

8 . The all-solid secondary battery of claim 7 ,
wherein the binder comprises styrene-butadiene rubber, polytetrafluoroethylene, poly(vinylidene fluoride), polyethylene, or a combination thereof.

9 . The all-solid secondary battery of claim 1 ,
wherein the ratio of the volume density to the true density of the positive electrode active material layer is about 0.7 to about 0.95.

10 . The all-solid secondary battery of claim 1 ,
wherein the negative electrode active material layer is a lithium metal layer.

11 . The all-solid secondary battery of claim 1 ,
wherein the lithium-containing alloy is an alloy of lithium metal and at least one of indium, aluminum, tin, and silicon.

12 . The all-solid secondary battery of claim 1 ,
wherein the solid electrolyte layer comprises a sulfide solid electrolyte material.

13 . The all-solid secondary battery of claim 1 ,
wherein the solid electrolyte layer comprises at least one of sulfur, silicon, phosphorus, and boron.

14 . The all-solid secondary battery of claim 1 ,
wherein the ratio of the volume density to the true density of the solid electrolyte layer is about 0.75 to about 0.995.

15 . The all-solid secondary battery of claim 1 ,
wherein the solid electrolyte layer has an average thickness of about 50 micrometers to about 100 micrometers.

16 . The all-solid secondary battery of claim 1 ,
wherein a surface of the cell has an area of about 20 square centimeters to about 1500 square centimeters.

17 . The all-solid secondary battery of claim 1 , wherein the battery comprises:
a pair of pressure applying members disposed on the opposite sides of the cell and configured to to apply pressure to the opposite sides of the cell; and a plurality of pressure control members disposed at each pressure application site of the pressure applying members to control the pressure applied by the pair of pressure applying members, wherein the pressure distribution is determined based on a pressure applied by each pressure control member.

18 . The all-solid secondary battery of claim 17 ,
wherein each of the pressure applying members and each of the plurality of pressure control members independently comprises stainless steel, steel, or a resin.

19 . The all-solid secondary battery of claim 17 , further comprising a pressure measuring film disposed between the pair of pressure applying members,
wherein the pressure applied to each pressure application site is measured by applying pressure to the pressure measuring film.

20 . The all-solid secondary battery of claim 1 ,
wherein the all-solid secondary battery has a capacity retention of greater than 80 percent after 50 cycles of charging and discharging at a temperature of 45° C. under a charge current 0.05 C, a discharge current of 0.05 C, and an operating voltage of 2.5 volts to 4 volts.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Fujiki Satoshi
• Yamada Takanobu
• Watanabe Taku
• Aihara Yuichi
• Tomoyuki Shiratsuchi

Classifications

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M2300/0065

  Solid electrolytes · CPC title