Sulfide solid electrolyte for lithium secondary battery with excellent mechanical properties and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-2025323313-A1
Application number	US-202418909383-A
Country	US
Kind code	A1
Filing date	Oct 8, 2024
Priority date	Apr 12, 2024
Publication date	Oct 16, 2025
Grant date	—

Abstract

A sulfide-based solid electrolyte with an argyrodite crystal structure is represented by the formula Li 7−x−3y Sb y PS 6−x Ha x , where Ha is one or more halogen elements selected from F, Cl, Br, I, and their combinations, is disclosed. The sulfide-based solid electrolyte comprises a substituted antimony (Sb) element in Wyckoff position 48h of the argyrodite crystal structure instead of Li. The sulfide-based solid electrolyte exhibits a downshifted argyrodite Raman peak compared to an electrolyte without antimony substitution. The disclosed solid electrolyte may be synthesized using a ball milling process to ensure uniform distribution of staring materials and achieve a disordered crystal structure that enhances lithium ion conductivity, pellet density, and fracture strength. The disclosed solid electrolyte can be used in lithium-ion batteries, which are suitable for vehicle applications.

First claim

1 . A sulfide solid electrolyte for a lithium secondary battery, the sulfide solid electrolyte comprising a lithium element, a phosphorus element, a sulfur element, and one or more halogen element,
wherein the sulfide electrolyte comprises an argyrodite crystal structure, wherein the sulfide electrolyte comprises an antimony (Sb) element in Wyckoff position 48h of the argyrodite crystal structure and, wherein a molar ratio of sum of the lithium element and the antimony element to the phosphorus element ((Li+Sb):P) is from 4.9 to 5.5.

2 . (canceled)

3 . The sulfide solid electrolyte of claim 1 represented by a formula:

wherein the Ha is selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), and
wherein the x is from 1.0 to 1.7 and the y is greater than 0 and less than or equal to 0 . 3 .

4 . The sulfide solid electrolyte of claim 1 represented by a formula:

wherein the Ha1 and the Ha2 are independently selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I),
wherein the x is from 1.0 to 1.7, the y is greater than 0 and less than or equal to 0.3, and the a is from 0 to 1.0, and
wherein the Ha1 and the Ha2 are different elements.

5 . The sulfide solid electrolyte of claim 1 comprising a Raman spectrum peak between 400 cm −1 and 450 cm −1 ,
wherein the Raman spectrum peak is downshifted from a Raman spectrum peak observed from a sulfide solid electrolyte not comprising antimony, and
wherein the Raman spectrum peak is associated with a presence of the argyrodite crystal structure.

6 . The sulfide solid electrolyte of claim 1 , wherein the sulfide solid electrolyte exhibits a fracture strength of 60 kPa or more as measured according to ASTM C773.

7 . The sulfide solid electrolyte of claim 1 , wherein the sulfide solid electrolyte has a pellet density from 1.8 g/cm 3 to about 2.0 g/cm 3 .

8 . A method of manufacturing a sulfide solid electrolyte for a lithium secondary battery, the method comprising:
reacting a starting material comprising lithium sulfide, phosphorus sulfide, one or more lithium halide, and antimony sulfide to obtain a mixture thereof; and heat-treating the mixture to obtain a sulfide solid electrolyte, wherein the sulfide solid electrolyte comprises an argyrodite crystal structure, wherein the sulfide solid electrolyte comprises a lithium element, a phosphorus element, a sulfur element, and one or more halogen element, and wherein the sulfide solid electrolyte comprises an antimony (Sb) element in in Wyckoff position 48h of the argyrodite crystal structure.

9 . The method of claim 8 , wherein the heat-treating is performed from about 450° C. to about 500° C.

10 . The method of claim 8 , wherein the heat-treating the product is performed from about 10 to about 30 minutes.

11 . The method of claim 8 , wherein a molar ratio of sum of the lithium element and the antimony element relative to the phosphorus element ((Li+Sb):P) in the sulfide solid electrolyte is from about 4.9 to about 5.5.

12 . The method of claim 8 , wherein the sulfide solid electrolyte is represented a formula:

wherein the Ha is selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and
wherein the x is from 1.0 to 1.7 and the y is from 0 to 0.3.

13 . The method of claim 8 , wherein the sulfide solid electrolyte is represented by a formula:

wherein the Ha1 and the Ha2 are independently comprise fluorine (F), chlorine (Cl), bromine (Br), or iodine (I),
wherein the x is from 1.0 to 1.7, the y is from 0.3 to 0.3, and the a is from 0 to 1.0, and
wherein the Ha1 and the Ha2 are different elements.

14 . The method of claim 8 , wherein the sulfide solid electrolyte comprises a Raman spectrum peak between 400 cm −1 to 450 cm −1 , and
wherein the Raman spectrum peak is downshifted with an increasing amount of antimony element present in the sulfide solid electrolyte.

15 . The method of claim 8 , wherein the sulfide solid electrolyte exhibits a fracture strength of about 60 kPa or more as measured according to ASTM C773.

16 . The method of claim 8 , wherein the sulfide solid electrolyte has a pellet density of about 1.8 g/cm 3 to about 2.0 g/cm 3 .

17 . The method of claim 8 , wherein the reacting lithium sulfide, phosphorus sulfide, one or more lithium halide, and antimony sulfide comprises using a ball milling to uniformly mix the starting material and provide reaction energy.

18 . The method of claim 8 , wherein the lithium halide is selected from the group consisting of LiF, LiCl, LiBr, LiI, and a combination thereof.

19 . A lithium secondary battery comprising:
a cathode layer; an anode layer; and a solid electrolyte layer disposed between the cathode layer and the anode layer, wherein at least one of the cathode layer, the anode layer, or the solid electrolyte layer comprises the sulfide solid electrolyte of claim 1 .

20 . A vehicle comprising the lithium secondary battery of claim 19 .

Assignees

• Hyundai Motor Co Ltd
• Kia Corp

Inventors

• Lee Sang Soo
• Min Hong Seok
• Lee Sang Heon
• Kim So Young
• Hwang Dae Yeon
• Kim Kwang Jin
• Jun Byeong Sun
• Jung Wo Dum
• Shin Geun Hyeong
• Kim Jae Young
• Song In Woo
• Shin Ho Cheol

Classifications

• H01M2300/0068

  inorganic · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M10/0525

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