Composite barium sulfate diaphragm and preparation method therefor, and lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2017338457-A1
Application number	US-201715674531-A
Country	US
Kind code	A1
Filing date	Aug 11, 2017
Priority date	Feb 12, 2015
Publication date	Nov 23, 2017
Grant date	—

Abstract

A composite barium sulfate diaphragm is disclosed. The composite barium sulfate diaphragm includes a base membrane, and a coating layer coated on the base membrane. The coating layer includes nano-barium sulfate. A surface of the nano-barium sulfate is modified with the lithium carboxylate group. A method for preparing the composite barium sulfate diaphragm and a lithium-ion battery are also provided.

First claim

What is claimed is:

1 . A composite barium sulfate diaphragm, comprising:
a base membrane; and a coating layer coated on the base membrane, the coating layer comprising a nano-barium sulfate and binder, and a surface of the nano-barium sulfate being modified with a lithium carboxylate group.

2 . The composite barium sulfate diaphragm of claim 1 , wherein the lithium carboxylate group comprises at least eight carbon atoms.

3 . The composite barium sulfate diaphragm of claim 1 , wherein the nano-barium sulfate is a mesoporous material.

4 . The composite barium sulfate diaphragm of claim 1 , wherein a thickness of the coating layer is in a range from about 2 μm to about 10 μm.

5 . A method for preparing a composite barium sulfate diaphragm, comprising:
mixing a lithium carboxylate solution and a soluble barium salt aqueous solution to form a first solution; providing a soluble sulfate aqueous solution with a pH of 8 to 10, and adding the soluble sulfate aqueous solution to the first solution to cause a reaction to obtain a precipitate; separating, water washing and drying the precipitate to obtain a nano-barium sulfate modified with a lithium carboxylate group; and mixing the nano-barium sulfate modified with the lithium carboxylate group and a binder to obtain a mixed slurry, and coating the mixed slurry on a base membrane.

6 . The method of claim 5 , wherein the lithium carboxylate solution is obtained by dissolving a lithium carboxylate in an organic solvent, and a volume ratio of the organic solvent to the soluble barium salt aqueous solution is in a range from about 1:1 to about 2:1.

7 . The method of claim 5 , wherein the lithium carboxylate is selected from the group consisting of lithium oleate, lithium stearate, lithium benzoate dodecyl, hexadecyl lithium benzoate, lithium polyacrylate, and combinations thereof.

8 . The method of claim 7 , wherein a mass of the lithium carboxylate is 1% to 5% by mass of a theoretical mass of the nano-barium sulfate modified with the lithium carboxylate group.

9 . The method of claim 5 , wherein the mixing the nano-barium sulfate modified with the lithium carboxylate group and the binder to obtain the mixed slurry, and coating the mixed slurry on the base membrane comprises:
mixing and agitating the nano-barium sulfate modified with the lithium carboxylate group and a polar solvent to uniformly disperse the nano-barium sulfate in the polar solvent to obtain a mixed solution; adding the binder to the mixed solution, and agitating the mixed solution to resolve the binder in the mixed solution to form the mixed slurry; and coating the mixed slurry on a surface of the base membrane to form a coating layer, and drying the base membrane to obtain the composite barium sulfate diaphragm.

10 . The method of claim 9 , wherein a mass ratio of the binder to the nano-barium sulfate modified with the lithium carboxylate group is in a range from about 5:100 to about 15:100 in the mixed slurry.

11 . A lithium-ion battery, comprising:
a cathode; an anode; a composite barium sulfate diaphragm disposed between the cathode and the anode; and a non-aqueous electrolyte permeated in the composite barium sulfate diaphragm, the composite barium sulfate diaphragm comprising:
a base membrane; and
a coating layer coated on the base membrane, the coating layer comprising a nano-barium sulfate and a binder, and a surface of the nano-barium sulfate being modified with the lithium carboxylate group.

12 . The lithium-ion battery of claim 11 , wherein the lithium carboxylate group comprises at least eight carbon atoms.

13 . The lithium-ion battery of claim 11 , wherein the nano-barium sulfate is a mesoporous material.

14 . The lithium-ion battery of claim 11 , wherein a thickness of the coating layer is in a range from about 2 μm to about 10 μm.

Assignees

• Jiangsu Huadong Inst Of Li-Ion Battery Co Ltd
• Univ Tsinghua

Inventors

• Shang yu-ming
• Ding xiao-lei
• He xiang-ming
• Wang Li
• Li Jian-Jun
• Liu Zhen
• Xu zhi-xin
• Wang yao-wu
• Gao Jian

Classifications

• H01M10/0525 Primary

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

• H01M50/451

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

• H01M50/42

  Acrylic resins · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/426

  Fluorocarbon polymers · CPC title