Process for preparing an electrode composition or composition with magnetic properties, mixture and composition obtained by means of said process and said electrode

Patent metadata

Field	Value
Publication number	US-10723846-B2
Application number	US-201415112990-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Feb 19, 2014
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

A process for preparing a polymeric composition for forming a lithium-ion or sodium-ion battery electrode or a supercapacitor electrode or for exhibiting magnetic properties, to such a polymeric composition obtained by means of this process, to a mixture which is a precursor of the composition, obtained by means of a first mixing step of the process, and to this electrode.
The process for preparing this composition comprises:
a) hot-mixing, via the melt process and without solvent, at least one active material, a binder-forming polymeric phase and a sacrificial polymeric phase so as to obtain a mixture, and b) at least partially eliminating said sacrificial polymeric phase so as to obtain said composition which comprises the active material(s) according to a weight fraction greater than 80%.

The sacrificial phase is used in step a) according to a weight fraction in the mixture being greater than or equal to 15%.

First claim

The invention claimed is:

1. A process for preparing a polymeric composition, the process comprising:
a) hot-mixing, by a melt process and without solvent, at least one active material, a binder-forming polymeric phase and a sacrificial polymeric phase to obtain a molten mixture, and
b) at least partially eliminating said sacrificial polymeric phase to obtain said polymeric composition which comprises the at least one active material according to a weight fraction greater than 80%,
wherein said sacrificial polymeric phase is used in step a) according to a weight fraction in said mixture which is greater than or equal to 15%,
wherein said binder-forming polymeric phase comprises at least one noncrosslinked elastomer chosen from a group consisting of hydrogenated butadiene/acrylonitrile copolymers (HNBR), ethylene/acrylate/maleic anhydride terpolymers, and mixtures thereof, said polymeric composition being devoid of a crosslinking agent,
wherein said sacrificial polymeric phase is eliminated in step b) via a thermal decomposition, and
wherein the polymeric composition forms a lithium-ion or sodium-ion battery electrode or a supercapacitor electrode, or exhibits magnetic properties.

2. The process as claimed in claim 1 , wherein said sacrificial polymeric phase is used in step a) according to a weight fraction in said mixture which is inclusively between 20% and 80%.

3. The process as claimed in claim 1 , wherein said sacrificial polymeric phase is used in step a) in the form of granules having a number-average size greater than 1 mm, and wherein step a) is carried out in an internal mixer or in an extruder without macrophase separation between said binder-forming polymeric phase and said sacrificial polymeric phase in said mixture, in which said binder-forming phase is homogeneously dispersed in said sacrificial polymeric phase which is continuous, or else forms a co-continuous phase with the latter.

4. The process as claimed in claim 1 , wherein said sacrificial polymeric phase has a thermal decomposition temperature which is at least 20° C. below a thermal decomposition temperature of said binder-forming phase.

5. The process as claimed in claim 4 , wherein said sacrificial polymeric phase is based on at least one sacrificial polymer chosen from polyalkene carbonates, preferably polyethylene carbonates and/or polypropylene carbonates.

6. The process as claimed in claim 1 , wherein said at least one elastomer is used in said mixture according to a weight fraction of between 1% and 12%.

7. The process as claimed in claim 1 , wherein said active material(s) is (are) present in said polymeric composition obtained in step b) according to a weight fraction preferably greater than or equal to 85%, and is (are) chosen from the group consisting of:
magnetic inorganic fillers, such as ferrites,
active inorganic fillers capable of allowing lithium insertion/deinsertion for lithium-ion battery electrodes, comprising lithiated polyanionic compounds or complexes such as a lithiated metal M phosphate of formula LiMPO 4 coated with carbon, a lithiated titanium oxide of formula Li 4 Ti 5 O 12 , oxides of formula LiCoO 2 , LiMnO 4 or LiNi 1/3 Mn 1/3 Co 1/3 O 4 , or graphite, and
fillers comprising porous carbon for supercapacitor electrodes.

8. The process as claimed in claim 1 , wherein said polymeric composition obtained in step b) has a volume porosity between 30% and 70% and is suitable for forming a lithium-ion or sodium-ion battery electrode or a supercapacitor electrode.

9. The process as claimed in claim 1 , wherein the process comprises, between steps a) and b), a step of fashioning by calendering said mixture obtained in step a), and wherein said polymeric composition obtained in step b) is formed from a sheet having a thickness of between 50 μm and 150 μm.

10. A polymeric composition forming a lithium-ion or sodium-ion battery electrode or a supercapacitor electrode or exhibiting magnetic properties, wherein said polymeric composition is made by the process of claim 1 , the polymeric composition comprises:
at least one active material according to a weight fraction greater than 80%;
a binder-forming polymeric phase; and
a sacrificial polymeric phase according to a weight fraction greater than or equal to 0.001%,
wherein said polymeric composition derives from a molten mixture of said at least one active material, said binder-forming polymeric phase and said sacrificial polymeric phase, in which said sacrificial polymeric phase has been partially eliminated,
wherein said polymeric composition is devoid of a solvent in which said at least one active material, said binder-forming polymeric phase and said sacrificial polymeric phase are dissolved or dispersed, and
wherein said binder-forming polymeric phase comprises at least one noncrosslinked elastomer chosen from a group consisting of hydrogenated butadiene/acrylonitrile copolymers (HNBR), ethylene/acrylate/maleic anhydride terpolymers, and mixtures thereof, said polymeric composition being devoid of a crosslinking agent.

11. A polymeric molten mixture usable for forming a precursor of said polymeric composition as claimed in claim 10 , wherein said polymeric molten mixture is obtained by hot-mixing, by a melt process and without solvent, said at least one active material, said binder-forming polymeric phase and said sacrificial polymeric phase, and wherein said polymeric molten mixture comprises said sacrificial polymeric phase according to a weight fraction in said mixture greater than or equal to 15% and preferably inclusively of between 20% and 80%.

12. The polymeric molten mixture as claimed in claim 11 , wherein said binder-forming polymeric phase is homogeneously dispersed in said sacrificial polymeric phase which is continuous, or else forms a co-continuous phase with the latter.

13. A lithium-ion or sodium-ion battery electrode or supercapacitor electrode, wherein it comprises the polymeric composition as claimed in claim 10 .

14. The electrode as claimed in claim 13 , wherein said polymeric composition also comprises an electrically conducting filler chosen from the group consisting of carbon black, graphite, expanded graphite, carbon fibers, carbon nanotubes, graphene and mixtures thereof, said electrically conducting filler being present in said polymeric composition according to a weight fraction of between 1% and 10%.

15. The process as claimed in claim 1 , wherein said at least one noncrosslinked elastomer is chosen from the group consisting of hydrogenated butadiene/acrylonitrile copolymers (HNBR), ethylene-ethyl acrylate-maleic anhydride terpolymers, and mixtures thereof.

16. The process as claimed in claim 1 , wherein said binder-forming polymeric phase consists of said at least one noncrosslinked elastomer.

17. The polymeric composition as claimed in claim 10 , wherein said at least one noncrosslinked elastomer is chosen from the group consisting of hydrogenated butadiene/acrylonitrile copolymers (HNBR), ethylene-ethyl acrylate-maleic anhydride terpolymers and mixtures thereof.

18. The polymeric composition as claimed in claim 10 , wherein said binder-forming polymeric phase consists of said at least one noncrosslinked elastomer.

19. The process as claimed in claim 7 , wherein said at least one active material is a magnetic inorganic filler chosen from the group consisting of ferrites, said polymeric composition exhibiting magnetic properties.

20. The process as claimed in claim 7 , wherein said at least one active material is an active inorganic f

Assignees

• Hutchinson

Inventors

• Sonntag Philippe
• Ayme-Perrot David
• Dufour Bruno
• Prebe Arnaud
• Garois Nicolas

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01G11/38 Primary

  Carbon pastes or blends; Binders or additives therein · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01F1/342

  Oxides (H01F1/36 and H01F1/38 take precedence) · CPC title

• H01G11/50

  specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation · CPC title