Method of producing electrode composite material

• US 20060263688A1
• Filed: 03/05/2004
• Published: 11/23/2006
• Est. Priority Date: 03/07/2003
• Status: Active Grant

• Current Assignee: Blue Solutions (Bollore SA), Centre National De La Recherche Scientifique
• Original Assignee: BatScap, Centre National De La Recherche Scientifique
• Inventors: Guy, Delphine, Gaubicher, Joël, Deschamps, Marc, Lestriez, Bernard, Guyomard, Dominique
• Granted Patent: US 8,632,904 B2
• Time in Patent Office: Days
• US Class Current: 429/217
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/50 specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 29/49108 : Electric battery cell making
• CPC Class Codes: Y10T 29/49115 : including coating or impregnating

Abstract

The invention relates to a method for producing a material for a composite electrode. The method is intended for the preparation of a composite material consisting of an active electrode material M1, a material C1 conferring electronic conductivity, an organic binder and a salt, said binder comprising a polymer P1 having an O, N, P or S heteroatom mass content of 15% or higher, a polymer P2 having an O, N, P or S heteroatom mass content of 5% or less, and a nonvolatile liquid organic solvent S1. It includes a step consisting in preparing a viscous solution containing at least one polymer P1, at least one polymer P2, a material C1, an active electrode material M1 and at least one nonvolatile solvent S1, and a step consisting in forming a film from the viscous solution obtained.

Claims

1. A method of preparing a composite material for electrodes, which comprises:

a 1st step of preparing a viscous solution containing at least one polymer P1 that has an O, N, P or S heteroatom mass content of 15% or higher, at least one polymer P2 that has an O, N, P or S heteroatom mass content of 5% or less, a material C1 conferring electronic conductivity, an active electrode material M1, and at least one nonvolatile solvent S1; and

a 2nd step of producing a film from the viscous solution obtained.

2. The method as claimed in claim 1, wherein it includes the introduction of a salt into the material.

3. The method as claimed in claim 2, wherein the salt is introduced into the material by adding said salt (by itself or in solution in a volatile solvent) during the preparation of the viscous solution.

4. The method as claimed in claim 2, wherein the salt is introduced by impregnating the film obtained from the viscous solution with a solution of said salt in a volatile solvent.

5. The method as claimed in claim 1, wherein it further includes a densification step comprising applying heat and pressure to the film.

6. The method as claimed in claim 1, wherein the polymer P1 is chosen from polyethers, polyesters, polyacrylic polymers, polycarbonates, polyimines, polyamides, polyacrylamides, polyurethanes, polyepoxides, polyphosphazenes or polysulfones.

7. The method as claimed in claim 6, wherein the polymer P1 is a polyether chosen from ethylene oxide, methylene oxide, propylene oxide, epichlorohydrin and allyl glycidyl ether homopolymers and copolymers, or a polyester chosen from ethylene terephthalate, butylene terephthalate and vinyl acetate homopolymers and copolymers.

8. The method as claimed in claim 6, wherein the polymer P1 is a polyacrylic polymer chosen from acrylamide, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate, stearyl acrylate, ethylene glycol diacrylate, triethylene glycol dimethacrylate, methyl methacrylate or acrylic acid homopolymers and copolymers.

9. The method as claimed in claim 6, wherein the polymer P1 is chosen from acrylonitrile homopolymers and copolymers, vinyl acetate and vinyl alcohol homopolymers and copolymers, homopolymers and copolymers of the carbonate of bisphenol A, polyethyleneimines and vinylpyrrolidone or vinyl sulfone homopolymers and copolymers.

10. The method as claimed in claim 1, wherein the polymer P2 is chosen from vinyl chloride, vinylidene fluoride, vinylidene chloride, tetrafluoroethylene and chlorotrifluoroethylene homopolymers and copolymers, or vinylidene fluoride/hexafluoropropylene copolymers.

11. The method as claimed in claim 1, wherein the polymer P2 is chosen from polyolefins or elastomers.

12. The method as claimed in claim 1, wherein the nonvolatile liquid organic solvent S1 consists of one or more compounds chosen from:

polar aprotic compounds, such as linear or cyclic carbonates, linear or cyclic ethers, linear or cyclic esters, linear or cyclic sulfones, sulfamides and nitriles;

phthalates, such as dioctyl phthalate, dibutyl phthalate and dimethyl phthalate; and

low-mass polyethylene glycols and poly(ethylene glycol) dimethyl ethers.

13. The method as claimed in claim 1, wherein the compound C1 is comprised of graphite, carbon fibers, carbon nanofils, carbon nanotubes, or electronically conductive polymers.

14. The method as claimed in claim 1, wherein, during the 1st step, the polymers are introduced in the pure state or in the form of a solution in a volatile solvent;

C1 is introduced in the pure state or in the form of a suspension or solution in a volatile solvent; and

M1 is introduced in the pure state or in the form of a suspension in a volatile solvent.

15. The method as claimed in claim 3, wherein the volatile solvent is chosen from acrylonitrile, acetonitrile, cyclohexanone or THF.

16. The method as claimed in claim 1, wherein the preparation of the viscous solution is carried out in a single phase.

17. The method as claimed in claim 1, wherein the preparation of the viscous solution comprises two successive phases, the first phase consisting in preparing a viscous solution containing all the constituents except for S1, in forming a film from this solution and in drying the film in order to obtain a powder, the second phase consisting in forming a new viscous solution by adding S1 to this powder, this new solution being used for producing the final film.

18. The method as claimed in claim 1, wherein the preparation of the viscous solution comprises two successive phases, the first phase comprising preparing a viscous solution containing all the constituents except for P2, in forming a film from this solution and in drying the film in order to obtain a powder, the second phase comprising forming a new viscous solution by adding a solution of P2 in a volatile solvent to said powder, this new solution being used for producing the final film.

19. The method as claimed in claim 1, wherein, during the 2nd step, the film is obtained from the viscous solution prepared during the 1st step, by extrusion or by coating on a substrate, followed by a drying step.

20. The method as claimed in claim 19, wherein the substrate used for the coating is a metal foil or mesh capable of serving as collector for the electrode.

21. The method as claimed in claim 1, wherein the active electrode material M1 is chosen from:

Li_1+xV₃O₈, where o<

x<

4;

Li_xV₂O₅·

nH₂O (where 0<

x<

3 and 0<

n<

2);

LiFePO₄;

hydrated or unhydrated iron phosphates and sulfates;

hydrated or unhydrated vanadyl phosphates and sulfates;

LiMn₂O₄ and compounds derived from LiMn₂O₄ that are obtained by substituting Mn with Al, Ni or Co;

LiNiO₂;

LiMnO₂ and compounds derived from LiMnO₂ that are obtained by substituting Mn with Al, Ni or Co;

or LiCoO₂ and compounds derived from LiCoO₂ that are obtained by substituting Co with Al, Ti, Mg, Ni or Mn.

22. The method as claimed in claim 1, wherein the active electrode material M1 is chosen from:

carbon compounds;

lithium alloys of the Li_xM type (where M=Sn, Sb S or Si) that are obtained from SnO, from SnO₂, from Sn, Sn—

Fe(—

C) compounds, from Si compounds or from Sb compounds;

or

Li_xCu₆Sn₅ compounds (where 0<

x<

13) , iron borates, pnictures (chosen from Li<sub>3−

x−

y</sub>Co_yN, Li<sub>3−

x−

y</sub>Fe_yN, Li_xMnP₄, Li_xFeP₂ and Li_xFeSb₂), simple oxides that undergo reversible decomposition, and insertion oxides, such as MoO₃ or WO₃ titanates.

23. A material obtained by [a] the method as claimed in claim 1, comprised of at least one polymer P1 that has an O, N, P or S heteroatom mass content of 15% or higher, at least one polymer P2 that has an O, N, P or S heteroatom mass content of 5% or less, a material C1 conferring electronic conductivity, an active electrode material M1 and at least one nonvolatile solvent S1, wherein, both on the micron scale and the submicron scale:

the polymer P1 and the material C1 conferring electronic conductivity form a dense, homogeneous and continuous phase around the particles of active material;

the polymer P2 is in the form of a dispersed phase which contains no or very little material C1 and the morphology of which phase, which is of the sphere, cylinder, needle or ribbon type, creates porosity.

24. The material as claimed in claim 23, wherein it contains a salt.

25. A composite electrode, wherein it is comprised of a film of a composite material as claimed in claim 23 deposited on a collector.

26. A composite electrode, wherein it is comprised of a film of a composite material as claimed in claim 24 deposited on a collector.

27. The composite electrode as claimed in claim 26, wherein the salt of the composite material is a lithium salt chosen from LiPF₆, LiAsF₆, LiC₄BO₈, LiClO₄, LiBF₄, Li(C₂F₅SO₂)₂N, LiCF₃SO₃, LiCH₃SO₃, Li[(C₂F₅)₃PF₃] or LiN(SO₂CF₃)₂.

28. The composite electrode as claimed in claim 26, wherein the salt of the composite material is a salt having a cation chosen from the cations:

R₃O⁺(oxonium), NR₄⁺(ammonium), RC(NHR₂)₂⁺(amidinium), C(NHR₂)₃⁺(guanidinium), C₅R₆N⁺(pyridinium) , C₃R₅N₂⁺(imidazolium), C₃R₇N₂⁺(imidazolinium), C₂R₄N₃⁺(triazolium), SR₃⁺(sulfonium) PR₄⁺(phosphonium), IR₂⁺(iodonium) or (C₆R₅)₃C⁺(carbonium) , in which the radicals R may be identical or different, said radicals being chosen from alkyl, alkenyl, oxaalkyl, oxaalkenyl, azaalkyl, azaalkenyl, thiaalkyl, thiaalkenyl, silaalkyl, silaalkenyl, aryl, arylalkyl, alkylaryl, alkenylaryl, dialkylamino or dialkylazo radicals.

29. The composite electrode as claimed in claim 28, wherein the radicals R preferably have at most 5 carbon atoms.

30. A battery formed by a positive electrode and a negative electrode separated by an electrolyte that includes a lithium salt, wherein at least one of its electrodes is an electrode as claimed in claim 25.

31. A supercapacitor formed by two electrodes separated by an electrolyte, wherein at least one of the electrodes is an electrode as claimed in claim 25.

32. The method as claimed in claim 4, wherein the volatile solvent is chosen from acrylonitrile, acetonitrile, cyclohexanone or THF.

33. The method as claimed in claim 14, wherein the volatile solvent is chosen from acrylonitrile, acetonitrile, cyclohexanone or THF.

34. A battery formed by a positive electrode and a negative electrode separated by an electrolyte that includes a lithium salt, wherein at least one of its electrodes is an electrode as claimed in claim 27.

35. A supercapacitor formed by two electrodes separated by an electrolyte, wherein at least one of the electrodes is an electrode as claimed in claims 28.