Electrode coated with a film obtained from an aqueous solution comprising a water-soluble binder, production method thereof and uses of same

Patent metadata

Field	Value
Publication number	US-2016156017-A1
Application number	US-201615014469-A
Country	US
Kind code	A1
Filing date	Feb 3, 2016
Priority date	Nov 13, 2002
Publication date	Jun 2, 2016
Grant date	—

Abstract

A method of preparing an electrochemical electrode which is partially or totally covered with a film that is obtained by spreading an aqueous solution comprising a water-soluble binder over the electrode and subsequently drying same. The production cost of the electrodes thus obtained is reduced and the surface porosity thereof is associated with desirable resistance values.

First claim

1 . (canceled)

2 . Electrode consisting of a support coated at least in part with a film containing one active material, said electrode being obtained by preparing an electrode partly coated with a film obtained by preparing an active material comprising LiFePO 4 coated with graphite and/or carbon by mechano-fusion or hybridization and spreading on a support an aqueous solution comprising the active material, at least one water soluble binder and at least one water soluble thickening agent.

3 . Electrode according to claim 2 , wherein the electrode is a cathode in which the electrode support is at least in part stainless, aluminum, copper, carbon, metal-plastic or a mixture of at least two of these materials.

4 . Electrode according to claim 2 , wherein the electrode is an anode in which the electrode support is at least in part copper, metal-plastic, or a mixture of at least two thereof.

5 . Electrode according to claim 2 , having at least one of the following properties:
a. storage stability, higher than 1 year, in the presence of a moisture content higher than 50% and in the presence of temperatures higher than 20° C.; b. a film thickness, when the latter is graphite based, of between 10 and 100 μm; c. a film thickness, when the latter is iron and/or phosphate based, of between 20 and 200 μm; d. electrochemical performances that compare to those of corresponding electrodes obtained with the same active material but by using an organic solvent solution; and e. an electrode film with particles of rubber directly attached to the electrode support.

6 . Electrode according to claim 5 , in which the porosity of the film that coats one or more of the electrodes, measured according to the method of thickness measurement, is between 10 and 90%.

7 . Electrode according to claim 6 , in which the porosity is between 30 and 40%.

8 . Process for preparing an electrochemical system including at least one anode, at least one cathode and at least one separator, the process comprising forming at least one anode and/or at least one cathode is as defined in claim 2 .

9 . Process according to claim 8 for the preparation of an electrochemical battery in which the separator is porous.

10 . Process for preparing an electrochemical battery according to claim 9 , in which the separator is of a PP or PE type or of a (PP,PE) mixture type.

11 . Process according to claim 8 , in which the separator is obtained by extrusion.

12 . Process according to claim 8 , in which the separator is of a gel type.

13 . Process according to claim 10 , in which the separator is obtained from a polymer materials selected from the group of:
polyester, poly(vinylydienefluoride) of chemical formula (CH 2 —CF 2 ) n , with n varying between 1000 and 4000; poly(vinylydiene fluoro-co-hexafluoropropene) copolymers, of formula [(CH 2 —CF 2 ) x (CF 2 —CF(CF 3 )) 1-x ] n in which n varies from 1000 to 4000, and x varies between 0.12 and 0.5; poly(tetrafluoroethylenes), of chemical formula (CF 2 —CF 2 ) n , with n varying from 5 to 20,000; poly(ethylene-co-propylene-co-5-methylene-2-norbornenes) or ethylene propylene-diene copolymers; the poly(methylmethacrylates), of formula [(CH 2 —C(CH 3 )/(CO 2 CH 3 )] n , with n varying between 100 and 10,000; and mixtures of at least two thereof.

14 . Process according to claim 13 , in which the separator is of the polyether PEO-PPO copolymer type.

15 . Process according to claim 14 , in which the separator is of the 3 branch polyether type or of the 4 branch polymer type.

16 . Process according to claim 15 , in which the separator is of a 4 branch polymer type.

17 . Electrochemical system obtained by a process comprising at least one process step as defined in claim 8 .

18 . Electrochemical system comprising at least one electrode as defined in claim 2 , and a separator of a gel, solid or liquid electrolyte type.

19 . Electrochemical system according to claim 17 , comprising an electrolyte gel.

20 . System according to claim 19 of the all liquid battery type, in which the electrolyte includes at least one salt and at least one solvent.

21 . System according to claim 20 , in which the salt molar concentration, in the electrolyte, is lower than or equal to 1 and the solvent molar concentration is higher than or equal to 1.

22 . System according to claim 20 , in which the salt is a salt of the imide family, of a type LiPF6, LiBF4, LiBOB, LiTFSI or LiFSI or a mixture of at least two of the latter.

23 . System according to claim 20 , in which the retained solvents have an elevated boiling point.

24 . System according to claim 23 , in which the solvent has a boiling point higher than 100° C.

25 . System according to claim 24 , in which the solvent is of the type γBL, TESA, or modified TESA, or mixtures thereof.

26 . System according to claim 20 , in which EC and PC solvents are used for the formation of the passivation film in the case of carbon based anodes, and PC solvent for low temperature applications.

27 . System according to claim 26 , in which the electrolyte for the all gel battery is obtained from a precursor made of a) a polymer+b) a liquid electrolyte.

28 . System according to claim 27 , in which the a) content varies from 1 to 99%; and the b) content varies from 1 to 99%, and the a and b contents agree with the relation (a)+(b)=100%, the % being given in weight.

29 . System according to claim 28 , in which a thermo-initiator is added in amounts proportional to the total weight a)+b).

30 . System according to claim 29 , in which the composition of the precursor is about 5% of a 4 branch polyether, and about 95% of an electrolyte of composition (1.5 LiTFSI+EC+PC+TESA+γBL (1:1:1:2)).

31 . System according to claim 30 in which, the concentration in lithium salt is higher than or equal to 1 M (1 molar) for the gels.

32 . System according to claim 30 , in which, the concentration in lithium salt is lower than or equal to 1 M (I molar) in the liquid electrolyte.

33 . Process for preparing an electrochemical separator comprising spreading on a support an aqueous solution, at least one water soluble binder and at least one water soluble thickening agent, wherein the aqueous solution contains no active materials nor carbon, or very small quantities thereof.

34 . Electrochemical system according to claim 33 in which the constituents have been prepared without using organic solvents.

Assignees

• Hydro Quebec

Inventors

• Zaghib Karim
• Armand Michel
• Guerfi Abdelbast
• Perrier Michel
• Dupuis Elisabeth
• Charest Patrick

Classifications

• H01M50/42

  Acrylic resins · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/426

  Fluorocarbon polymers · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/406

  Moulding; Embossing; Cutting · CPC title