Separator for electrochemical device, and electrochemical device having same

Patent metadata

Field	Value
Publication number	US-2025183479-A1
Application number	US-202318843375-A
Country	US
Kind code	A1
Filing date	Oct 17, 2023
Priority date	Oct 17, 2022
Publication date	Jun 5, 2025
Grant date	—

Abstract

Disclosed is a separator for an electrochemical device containing a lithium manganese-based active material. The separator includes a porous polymer substrate, and a porous coating layer which is laminated on at least one surface of the porous polymer substrate and contains inorganic particles and a polymer binder. The inorganic particles have a sulfonic acid group introduced on the surface of a metal oxide or metal hydroxide, and at least a portion of the sulfonic acid group has hydrogen cations substituted with lithium cations.

First claim

1 . A separator for an electrochemical device comprising a lithium manganese-based active material, the electrochemical device comprising:
a porous polymer substrate; and a porous coating layer laminated on at least one surface of the porous polymer substrate and comprising first inorganic particles and a polymer binder, wherein the first inorganic particles comprise a sulfonic acid group on a surface of a metal oxide or a metal hydroxide, and at least a portion of the sulfonic acid group comprises hydrogen cations substituted with lithium cations.

2 . The separator for the electrochemical device of claim 1 , wherein the porous coating layer further comprises second inorganic particles that are a metal oxide or a metal hydroxide comprised in the porous coating layer, and the first inorganic particles and the second inorganic particles are comprised at a weight ratio of 80:20 to 70:30.

3 . The separator for the electrochemical device of claim 1 , wherein the sulfonic acid group is at least one selected from the group consisting of methane sulfonic acid, ethane sulfonic acid, trifluoromethanesulfonic acid, benzene sulfonic acid, p-toluene sulfonic acid, naphthalene sulfonic acid, phenylbenzimidazole sulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid.

4 . The separator for the electrochemical device of claim 1 , wherein the metal oxide or the metal hydroxide is at least one or more-selected from the group consisting of HfO 2 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 , SrTiO 3 , SnO 2 , CeO 2 , MgO, Mg(OH) 2 , NiO, CaO, ZnO, Zn 2 SnO 4 , ZnSnO 3 , ZnSn(OH) 6 , ZrO 2 , Y 2 O 3 , SiO 2 , Al 2 O 3 , AlOOH, Al(OH) 3 , and TiO 2 .

5 . The separator for the electrochemical device of claim 1 , wherein the polymer binder is a non-aqueous polymer binder, and forms an interstitial volume formed by a gap between the first inorganic particles by binding the first inorganic particles to each other.

6 . The separator for the electrochemical device of claim 5 , wherein the non-aqueous polymer binder is at least one selected from the group consisting of polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-co-HFP), and N,N′-bis[3(triethoxysilyl)propyl]urea.

7 . The separator for the electrochemical device of claim 1 , wherein the lithium manganese-based active material is one or more cathode active materials selected from the group consisting of Li 1+x Mn 2−x O 4 (0<x<0.33), LiMnO 3 , LiMn 2 O 3 , LiMnO 2 , LiNi 1−x Mn x O 2 (0.01≤x<0.3), LiMn 2−x M x O 2 (M═Co, Ni, Fe, Cr, Zn, or Ta, and 0.01≤x<0.1), Li 2 Mn 3 MO 8 (M═Fe, Co, Ni, Cu, or Zn), LiNi x Mn 2−x O 4 (0<x<0.5), and LiMn 2 O 4 .

8 . The separator for the electrochemical device of claim 1 , wherein the porous coating layer has a thickness of 1 μm to 6 μm.

9 . The separator for the electrochemical device of claim 1 , wherein the separator has an adsorption rate of manganese ions eluted from a cathode comprising the lithium manganese-based active material of 15% to 30%.

10 . An electrochemical device comprising:
a cathode; an anode; and a separator between the cathode and the anode, wherein the separator is the separator for an electrochemical device according to claim 1 .

11 . A lithium secondary battery comprising the electrochemical device according to claim 10 .

12 . The separator for the electrochemical device of claim 2 , wherein the second inorganic particles do not have a sulfonic acid group on a surface of the metal oxide or the metal hydroxide.

13 . The separator for the electrochemical device of claim 1 , wherein the first inorganic particles have an average particle diameter of 50 nm to 5000 nm.

14 . The separator for the electrochemical device of claim 1 , wherein the first inorganic particles have a specific surface area of 5 m 2 /g to 10 m 2 /g.

15 . The separator for the electrochemical device of claim 1 , wherein the first inorganic particles and the second inorganic particles have an average specific surface area of 5.5 m 2 /g to 6.5 m 2 /g.

16 . The separator for the electrochemical device of claim 1 , wherein the porous coating layer has a thickness of 3 μm to 5 μm.

Assignees

• Lg Energy Solution Ltd

Inventors

• Yoon Yeo Ju
• Kim Seong Jun
• Jeong So Mi

Classifications

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/446 Primary

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M10/052

  Li-accumulators · CPC title