Method of preparing dry electrode film, dry electrode film, dry electrode including the dry electrode film, and lithium battery including the dry electrode film

Patent metadata

Field	Value
Publication number	US-2024322112-A1
Application number	US-202318485162-A
Country	US
Kind code	A1
Filing date	Oct 11, 2023
Priority date	Mar 26, 2023
Publication date	Sep 26, 2024
Grant date	—

Abstract

A method of preparing a dry electrode film, the dry electrode film, a dry electrode including the dry electrode film, and a lithium battery including the dry electrode film is provided. The method includes providing frozen first dry binder particles, pulverizing the frozen first dry binder particles to prepare second dry binder particles, mixing a dry electrode active material and the second dry binder particles to prepare a dry electrode mixture, and processing the dry electrode mixture into a dry electrode film including a dry binder through a rolling device including a calender roll. A second particle diameter of the second dry binder particles is less than a first particle diameter of the frozen first dry binder particles.

First claim

What is claimed is:

1 . A method of preparing a dry electrode film, the method comprising:
providing frozen first dry binder particles; pulverizing the frozen first dry binder particles to prepare second dry binder particles; mixing a dry electrode active material and the second dry binder particles to prepare a dry electrode mixture; and processing the dry electrode mixture into a dry electrode film comprising a dry binder through a rolling device comprising a calender roll, wherein a second particle diameter of the second dry binder particles is less than a first particle diameter of the frozen first dry binder particles.

2 . The method as claimed in claim 1 , wherein the first particle diameter of the frozen first dry binder particles is 200 μm or more, and the second particle diameter of the second dry binder particles is 100 μm or less.

3 . The method as claimed in claim 1 , wherein the pulverizing is performed at a temperature of −10° C. or less for about 0.5 minutes to about 10 minutes.

4 . The method as claimed in claim 1 , wherein, in an X-ray diffraction (XRD) spectrum of the second dry binder particles,
a degree of crystallinity, which is a ratio of an area of a (100) crystalline peak at a diffraction angle (2θ) of about 18°±1.5° to a total peak area of the (100) crystalline peak at the diffraction angle (2θ) of about 18°±1.5° and an amorphous peak at a diffraction angle (2θ) of about 16.5°±3.0°, is about 50% to about 90%.

5 . The method as claimed in claim 1 , wherein the dry electrode mixture further comprises a dry conductive material,
the dry conductive material comprises a carbon-based conductive material, the carbon-based conductive material comprises a fibrous carbon-based material having an aspect ratio of 10 or more, a particulate carbon-based material having an aspect ratio of less than 10, or a combination thereof, and a content of the dry conductive material is about 0.1 wt % to about 5 wt % with respect to a total weight of the dry electrode film.

6 . The method as claimed in claim 1 , wherein the dry binder comprises a fibrillized binder or comprises a fluorine-based binder, and
a glass transition temperature (T g ) of the dry binder about 15° C. to about 150° C.

7 . The method as claimed in claim 1 , wherein a content of the dry binder is about 0.1 wt % to about 2 wt % with respect to a total weight of the dry electrode film.

8 . The method as claimed in claim 1 , wherein a dry electrode film, which is prepared using a dry electrode mixture which comprises the frozen first dry binder particles, has a first elongation at break (EB 1 ), and
a dry electrode film, which is prepared using a dry electrode mixture which comprises the second dry binder particles, has a second elongation at break (EB 2 ), wherein a ratio (EB 2 /EB 1 ) of the second elongation at break to the first elongation at break is 1.1 or more.

9 . The method as claimed in claim 8 , wherein the second elongation at break (EB 2 ) of the dry electrode film is 14% or more.

10 . The method as claimed in claim 1 , wherein a dry electrode film, which is prepared using a dry electrode mixture which comprises the second dry binder particles, has a first tensile strength at break (TSB 1 ), and
a dry electrode film, which is prepared using a dry electrode mixture which comprises the second dry binder particles, has a second tensile strength at break (TSB 2 ), wherein a ratio (TSB 2 /TSB) of the second tensile strength at break to the first tensile strength at break is 1.1 or more.

11 . The method as claimed in claim 10 , wherein the second tensile strength at break of the dry electrode film is 0.5 newton per square millimeter (N/mm 2 ) or more.

12 . The method as claimed in claim 1 , wherein the dry electrode film is free of a residual process solvent.

13 . The method as claimed in claim 1 , wherein the dry electrode film is a self-standing film.

14 . The method as claimed in claim 1 , wherein the dry electrode active material comprises a lithium transition metal oxide, and
the lithium transition metal oxide is represented by a formula selected from among Formulas 1 to 8:
Li a Ni x Co y M z O 2-b A b   Formula 1

wherein, in Formula 1, 1.0≤a≤1.2, 0≤b≤0.2, 0.8≤x<1, 0≤y≤0.3, 0<z≤0.3, x+y+z=1, M is manganese (Mn), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr)), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B), or a combination thereof, and A is F, S, Cl, Br, or a combination thereof,
LiNi x Co y Mn z O 2   Formula 2

LiNi x Co y Al z O 2   Formula 3

wherein, in Formula 2 and Formula 3, 0.8≤x≤0.95, 0≤y≤0.2, 0<z≤0.2, and x+y+Z=1,
LiNi x Co y Mn z Al w O 2   Formula 4

wherein, in Formula 4, 0.8≤x≤0.95, 0≤y≤0.2, 0<z≤0.2, 0<w≤0.2, and x+y+z+W=1,
Li a Co x M y O 2-b A b   Formula 5

wherein, in Formula 5, 1.0≤a≤1.2, 0≤b≤0.2, 0.9≤x≤1, 0≤y≤0.1, x+y=1, M is manganese (Mn), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr)), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B), or a combination thereof, and A is F, S, Cl, Br, or a combination thereof,
Li a Ni x Mn y M′ z O 2-b A b   Formula 6

wherein, in Formula 6, 1.0≤a≤1.2, 0≤b≤0.2, 0<x≤0.3, 0.5≤y<1, 0<z≤0.3, x+y+z=1, M′ is cobalt (Co), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B), or a combination thereof, and A is F, S, Cl, Br, or a combination thereof,
Li a M1 x M2 y PO 4-b X b   Formula 7

wherein, in Formula 7, 0.90≤a≤1.1, 0≤x≤0.9, 0≤y≤0.5, 0.9<x+y<1.1, 0≤b≤2, M1 is chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), or a combination thereof, and M2 is magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), zinc (Zn), boron (B), niobium (Nb), gallium (Ga), indium (In), molybdenum (Mo), tungsten (W), aluminum (Al), silicon (Si), chromium (Cr), vanadium (V), scandium (Sc), yttrium (Y), or combinations thereof, and X is O, F, S, P, or combinations thereof, and
Li a M3 z PO 4   Formula 8

wherein, in Formula 8, 0.90≤a≤1.1, 0.9≤z≤1.1, and M3 is chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), or a combination thereof.

15 . A dry electrode film being prepared through the method of preparing a dry electrode film as claimed in claim 1 , wherein
the dry electrode film is prepared utilizing the second dry binder particles obtained by pulverizing the frozen first dry binder particles, in an XRD spectrum of the second dry binder particles, a degree of crystallinity, which is a ratio of an area of a (100) crystalline peak at a diffraction angle (2θ) of about 18°±1.0° to a total peak area at a diffraction angle (2θ) of about 15° to about 20°, is about 50% to about 90%, a binder content of the dry electrode film is about 0.1 wt % to about 2 wt % of a total weight of the dry electrode film, elongation at break of the dry electrode film is 14% or more, and the dry electrode film is a self-standing film.

16 . The dry electrode film as claimed in claim 15 , wherein tensile strength at break of the dry electrode film is 0.50 N/mm 2 or more.

17 . A dry electrode comprising:
an electrode current collector; and
the dry electrode film as claimed in claim 15 on at least one surface of the electrode current

Assignees

• Samsung Sdi Co Ltd

Inventors

• Nam Hyun
• Lee Jinhyon
• Pyun Ahram
• Kwon Ilkyong
• Yoon Yeonhee
• Lee Donggeun
• Kim Seongdae
• Kwon Seunguk
• Bang Youmin
• Choi Jongsup

Classifications

• H01M10/0525

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

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M4/663

  containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• H01M4/623

  fluorinated polymers · CPC title