Crosslinked Structure-Containing Polyolefin Porous Support, Crosslinked Structure-Containing Separator For Lithium Secondary Battery Including The Same, And Lithium Secondary Battery Including The Separator

Patent metadata

Field	Value
Publication number	US-2024372221-A1
Application number	US-202218289387-A
Country	US
Kind code	A1
Filing date	May 9, 2022
Priority date	May 7, 2021
Publication date	Nov 7, 2024
Grant date	—

Abstract

The present disclosure relates to a crosslinked structure-containing polyolefin porous support which has a crosslinked structure including polymer chains interconnected directly with one another, wherein a first peak is detected at a g value of 2.010-2.030 as determined by electron spin resonance spectroscopy by irradiating ultraviolet rays thereto at 500 W. The present disclosure also relates to a crosslinked structure-containing separator for a lithium secondary battery including the crosslinked structure-containing polyolefin porous support, and a lithium secondary battery including the separator. The crosslinked structure-containing polyolefin porous support shows excellent heat resistance.

First claim

1 . A crosslinked structure-containing polyolefin porous support which has a crosslinked structure comprising polymer chains interconnected directly with one another, wherein a first peak is detected at a g value of 2.010-2.030 as determined by electron spin resonance spectroscopy by irradiating ultraviolet rays thereto at 500 W.

2 . The crosslinked structure-containing polyolefin porous support according to claim 1 , wherein a second peak is further detected at a g value of 1.990-2.009 as determined by electron spin resonance spectroscopy by irradiating ultraviolet rays thereto at 500 W.

3 . The crosslinked structure-containing polyolefin porous support according to claim 2 , wherein a ratio of an area of the first peak based on an area of the second peak is from 10 to 200%, as determined by electron spin resonance spectroscopy by irradiating ultraviolet rays thereto at 500 W.

4 . The crosslinked structure-containing polyolefin porous support according to claim 1 , which shows a ratio (A/B) of storage modulus G′ (A) to loss modulus G″ (B) of 2 or more, at a range of frequency of 1 rad/s or less in a frequency-loss/storage modulus curve, a horizontal axis of which is a frequency (rad/s) converted into a log scale and a vertical axis of which is storage modulus G′ (A) and loss modulus G″ (B) converted into a log scale.

5 . The crosslinked structure-containing polyolefin porous support according to claim 1 , which shows a gradient of a curve of storage modulus G′ (A) vs. frequency of 0.05-0.4, at a range of frequency of 10 −1 to 1 rad/s in a frequency-loss/storage modulus curve, a horizontal axis of which is a frequency (rad/s) converted into a log scale and a vertical axis of which is storage modulus G′ (A) and loss modulus G″ (B) converted into a log scale.

6 . The crosslinked structure-containing polyolefin porous support according to claim 4 , wherein the storage modulus is from 1.0×10 5 to 1.0×10 7 Pa.

7 . The crosslinked structure-containing polyolefin porous support according to claim 4 , wherein the loss modulus is from 3.0×10 5 Pa or less.

8 . A crosslinked structure-containing separator for a lithium secondary battery comprising the crosslinked structure-containing polyolefin support of claim 1 .

9 . The crosslinked structure-containing separator according to claim 8 , further comprising an inorganic composite porous layer disposed on at least one surface of the crosslinked structure-containing polyolefin porous support and the inorganic composite porous layer comprising an inorganic filler and a binder polymer.

10 . The crosslinked structure-containing separator according to claim 8 , further comprising an inorganic composite porous layer disposed on at least one surface of the crosslinked structure-containing polyolefin porous support, the inorganic composite porous layer comprising an inorganic filler and a first binder polymer; and
a porous adhesive layer disposed on the inorganic composite porous layer, the porous adhesive layer comprising a second binder polymer.

11 . The crosslinked structure-containing separator according to claim 8 , which has a meltdown temperature of 160° C. or higher.

12 . The crosslinked structure-containing separator according to claim 8 , which has a shutdown temperature of 145° C. or less.

13 . A lithium secondary battery comprising a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode, wherein the separator for a lithium secondary battery is the crosslinked structure-containing separator of claim 8 .

Assignees

• Lg Chemical Ltd

Inventors

• Han Sung-Jae
• Lee Joo-Sung
• Mun Sung Cik

Classifications

• H01M50/449

  having a layered structure · CPC title

• H01M50/446

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

• H01M50/403

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/461

  with adhesive layers between electrodes and separators · CPC title