Positive-electrode mixture, manufacturing method therefor, and all-solid-state lithium-sulfur battery

Patent metadata

Field	Value
Publication number	US-2016254529-A1
Application number	US-201415027162-A
Country	US
Kind code	A1
Filing date	Oct 1, 2014
Priority date	Oct 16, 2013
Publication date	Sep 1, 2016
Grant date	—

Abstract

The present invention aims to maximize the advantageous physical properties of sulfur and provide a cathode mixture that can be suitably used in a cathode mixture layer of an all-solid-state lithium-sulfur battery having excellent charge/discharge capacity. The present invention also aims to provide an all-solid-state lithium-sulfur battery including a cathode mixture layer containing the cathode mixture. The present invention relates to a cathode mixture for use in a cathode mixture layer of an all-solid-state lithium-sulfur battery, the cathode mixture containing the following components (A) to (D): (A) sulfur and/or its discharge product; (B) elemental phosphorus and/or P x S y where x and y independently represent an integer that gives a stoichiometric ratio; (C) an ion-conductive material; and (D) a conductive material.

First claim

1 . A cathode mixture for use in a cathode mixture layer of an all-solid-state lithium-sulfur battery, the cathode mixture comprising the following components (A) to (D):
(A) sulfur and/or its discharge product; (B) elemental phosphorus and/or P x S y where x and y independently represent an integer that gives a stoichiometric ratio; (C) an ion-conductive material; and (D) a conductive material.

2 . The cathode mixture according to claim 1 ,
wherein the component (C) is a composite of Li, S, and P.

3 . The cathode mixture according to claim 1 ,
wherein the component (C) contains P at a weight ratio of 0.15 to 0.55.

4 . The cathode mixture according to claim 2 ,
wherein the composite of Li, S, and P is obtained by mechanically milling at least a combination of Li 2 S, S, and P, or at least a combination of Li 2 S and P x S y where x and y independently represent an integer that gives a stoichiometric ratio.

5 . The cathode mixture according to claim 1 ,
which is obtained by mixing the component (A) and the component (B) first and then mixing the resulting mixture with the component (C) and the component (D).

6 . The cathode mixture according to claim 1 ,
wherein the component (B) is present in an amount of 1 to 35% by weight of the amount of the component (A).

7 . The cathode mixture according to claim 1 ,
wherein the component (D) comprises a conductive component (D1) that comprises a carbon material having a specific surface area of 1000 m 2 /g or more.

8 . The cathode mixture according to claim 7 ,
wherein the component (D) further comprises at least one conductive component (D2) selected from the group consisting of graphite, acetylene black, carbon nanotube, and carbon fiber.

9 . The cathode mixture according to claim 1 ,
wherein the component (A) and the component (B) are present in a combined amount of 40% by weight or more of the total cathode mixture.

10 . The cathode mixture according to claim 4 ,
wherein the composite of Li, S, and P is obtained by mechanically milling the combination of Li 2 S, S, and P or the combination of Li 2 S and P x S y , and further at least one selected from the group consisting of M z S where M represents Si, Ge, B, or Al, and z represents an integer that gives a stoichiometric ratio, phosphorus oxide, lithium oxide, and lithium iodide.

11 . An all-solid-state lithium-sulfur battery, comprising:
a cathode mixture layer comprising the cathode mixture according to claim 1 ; a solid electrolyte layer; an anode; and a current collector.

12 . A method for producing the cathode mixture according to claim 1 , the method at least comprising:
step (1) of mixing the component (A) and the component (B); and step (2) of mixing a mixture obtained in the step (1) with the component (C) and the component (D) simultaneously or separately.

Assignees

• Nagase Chemtex Corp

Inventors

• Nagata Hiroshi
• Chikusa Yasuo

Classifications

• H01M4/5815

  Sulfides · CPC title

• H01M4/04

  Processes of manufacture in general · CPC title

• H01M4/136 Primary

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title