Primer for battery electrode

Patent metadata

Field	Value
Publication number	US-2025054988-A1
Application number	US-202218722471-A
Country	US
Kind code	A1
Filing date	Dec 15, 2022
Priority date	Dec 20, 2021
Publication date	Feb 13, 2025
Grant date	—

Abstract

The present invention relates to a primer that improves adhesiveness between an electro active material and a current collector, and to an electrode comprising the same.

First claim

1 . An electrode, electrode (E), comprising:
a surface-modified metal substrate having at least one side that is at least partially chemically modified, a first layer adhered to said at least one surface of said metal substrate, said first layer comprising at least one copolymer, copolymer (A), obtained by radical polymerization of at least one phosphorus-containing unsaturated monomer with acrylic acid and/or methacrylic acid, and a second layer, adhered to said first layer, comprising at least a composition, composition (C EA ), comprising at least one electrode active material, compound (AM), and at least one binder, binder (B).

2 . The electrode (E) according to claim 1 , wherein said copolymer (A) is obtained by radical polymerization of:
at least one phosphorus-containing unsaturated monomer of formula (a) or (b):

wherein n is 1 or 2;
(b) H 2 C═CH—P(═O)—(OH) 2 ;
with acrylic acid and/or methacrylic acid.

3 . The electrode (E) according to claim 2 , wherein said copolymer (A) is obtained by radical copolymerization of the phosphorus-containing unsaturated monomer of formula (b) H 2 C═CH—O—P(═O)—(OH) 2 with acrylic acid.

4 . The electrode (E) according to claim 3 , wherein said phosphorus-containing unsaturated monomer of formula (b) and the acrylic acid are in a molar ratio from 40:60 to 20:80.

5 . The electrode (E) according to claim 2 , wherein said copolymer (A) is obtained by radical copolymerization of:
a 2-hydroxyethyl methacrylate phosphate complying with formula (a), wherein n is 1, a 2-hydroxyethyl methacrylate phosphate complying with formula (a) wherein n is 2, with acrylic acid and methacrylic acid.

6 . The electrode (E) according to claim 5 , wherein said copolymer (A) is obtained by radical copolymerization of a mixture having the following molar ratio, based on the total quantity of acrylic acid, methacrylic acid and 2-hydroxyethyl methacrylate phosphates of Formula (a):
acrylic acid: from 65 to 90%, methacrylic acid: from 5 to 30%, 2-hydroxyethyl methacrylate phosphates: from 2 to 12%.

7 . The electrode (E) according tom claim 1 , wherein said electrode is a positive electrode;
said metal substrate comprises at least one metal selected from the group consisting of aluminium (Al), nickel (Ni), titanium (Ti), and alloys thereof; said compound (AM) comprises:
(I) a composite metal chalcogenide of formula LiMQ2, wherein M is at least one metal selected from Co, Ni, Fe, Mn, Cr, V Al, and mixtures thereof and Q is a chalcogen, or
(II) a lithiated or partially lithiated transition metal oxyanion-based electro-active material of formula M1M2(JO4)fE1-f, wherein M1 is lithium, which is optionally partially substituted by another alkali metal representing less than 20% of the M1 metals, M2 is a transition metal at the oxidation level of +2 selected from Fe, Mn, Ni or mixtures thereof, which is optionally partially substituted by one or more additional metals at oxidation levels between +1 and +5 and representing less than 35% of the M2 metals, including 0, JO4 is any oxyanion wherein J is either P, S, V, Si, Nb, Mo or a combination thereof, E is a fluoride, hydroxide or chloride anion, f is the molar fraction of the JO4 oxyanion, generally comprised between 0.75 and 1; and/or
said binder (B) is selected from semi-crystalline polymers or elastomers.

8 . The electrode (E) according to claim 7 , wherein said binder (B) is selected from VDF-based polymers, selected from the group consisting of: VDF homopolymer and copolymer of VDF with at least one (per)fluorinated monomer different from VDF and/or at least one (meth)acrylic monomer.

9 . The electrode (E) according to claim 1 , wherein said electrode is a negative electrode; said metal substrate comprises silicon (Si) or at least one metal selected from the group consisting of lithium (Li), sodium (Na), zinc (Zn), magnesium (Mg), copper (Cu) and alloys thereof; said compound (AM) comprises:
graphitic carbons able to intercalate Lithium; Lithium metal; Lithium alloy compositions; Lithium titanates; Lithium-silicon alloys; Lithium-germanium alloys; Lithium-tin and Lithium-antimony alloys; and/or said binder (B) is selected from aqueous solutions of polyacrylic acid, carboxymethyl cellulose with styrene butadiene.

10 . A method for the manufacture of an electrode (E) according to claim 1 , said method comprising:
step (1) of providing a metal substrate having at least one surface; step (1b) of surface treatment of said at least one surface of said metal substrate to provide a surface-modified metal substrate having at least one side that is at least partially chemically modified; step (2) of contacting at least one copolymer (A) obtained by radical polymerization of at least one phosphorus-containing unsaturated monomer with acrylic acid and/or methacrylic acid, with said at least one surface of said metal substrate, thus providing a first layer; step (3) contacting said first layer with an electrode-forming composition, composition (CE), comprising at least one electrode active material, compound (AM), at least one binder, binder (B), and at least one solvent, solvent (S).

11 . The method according to claim 10 , wherein:
said step (1b) of surface treatment is performed via chemical etching; and/or after step (1b) and before step (2), at least one step of cleaning and/or rinsing said at least one surface of said metal substrate is performed; and/or after said step (2) and before step (3), at least one step of rinsing is performed; and/or after said step (3), at least one step of drying and/or compression is performed.

12 . The method according to claim 10 , wherein said solvent (S) is an organic polar solvent.

13 . An electrochemical device comprising a positive electrode and a negative electrode, wherein at least one of said positive electrode and said negative electrode is electrode (E) according to claim 1 .

14 . A method of producing a primer in a current collector of an electrochemical device comprising radical polymerization of at least one phosphorus-containing unsaturated monomer with acrylic acid and/or methacrylic acid to obtain at least one copolymer (A).

15 . The electrode (E) according to claim 5 , wherein said copolymer (A) is obtained by radical copolymerization of a mixture having the following molar ratio, based on the total quantity of acrylic acid, methacrylic acid and 2-hydroxyethyl methacrylate phosphates of Formula (a):
acrylic acid: from 80 to 90%, methacrylic acid: from 5 to 15%, 2-hydroxyethyl methacrylate phosphates: from 2 to 10%.

16 . The electrode (E) according to claim 5 , wherein said copolymer (A) is obtained by radical copolymerization of a mixture having the following molar ratio, based on the total quantity of acrylic acid, methacrylic acid and 2-hydroxyethyl methacrylate phosphates of Formula (a):
acrylic acid: from 83 to 85%, methacrylic acid: from 11 to 13%, 2-hydroxyethyl methacrylate phosphates: from 2 to 6%.

17 . The method according to claim 10 , wherein said solvent (S) is an organic polar solvent selected from the group consisting of: N-methyl-2-pyrrolidone (NPM), N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphamide, dioxane, tetrahydrofuran, tetramethylurea, triethyl phosphate, trimethyl phosphate and mixtures thereof; and isobutyl-nitrile, isobutyl-butyrate, dibutylether, methyl isobutyl ketone, dibutyl carbonate, tert-butyl acetoacetate.

Assignees

• Solvay Specialty Polymers It

Inventors

• Liberale Francesco
• Pieri Riccardo Rino
• Biso Maurizio
• Labeau Marie-Pierre
• Moreau Patrick

Classifications

• H01M10/0525

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

• H01M4/661

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

• H01M4/622

  being polymers · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/043

  involving compressing or compaction · CPC title