Aqueous polyvinylidene fluoride composition
AssigneeArkema Inc.
InventorsRamin AMIN-SANAYEI, Ravi R. Gupta
Life of this patent
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Abstract
The invention relates to an aqueous fluoropolymer, and preferably polyvinylidene fluoride (PVDF), composition for manufacturing electrodes for use in non-aqueous-type electrochemical devices, such as batteries and electric double layer capacitors. The composition contains aqueous PVDF binder, and one or more powdery electrode-forming materials. In one embodiment, the composition is free of fluorinated surfactant In another embodiment, one or more fugitive adhesion promoters are added. The electrode formed from the composition of the invention exhibits interconnectivity and irreversibility that is achieved from the use of aqueous PVDF binder.
Claims24
An aqueous composition comprising:
- a) from 0.2 to 150 parts fluoropolymers particles having a weight average particle size of less than 500 nm;
- b) from 10 to 500 parts of one or more powdery electrode-forming materials;
- c) optionally from 0 to 10 parts of one or more thickeners;
- d) optionally, one or more pH adjusting agents;
- e) optionally from 0 to 10 parts of one or more additives selected from the group consisting of anti-settling agents and surfactants;
- f) optionally from 0 to 5 parts of one or more wetting agents;
- g) optionally from 0 to 150 parts of one or more fugitive adhesion promoters;
- h) 100 parts water;
- all parts being parts by weight based on 100 parts by weight of water, and wherein the composition contains no fluorosurfactant.
An aqueous composition comprising:
- a) from 0.2 to 150 parts polyvinylidene fluoride (PVDF) particles having a weight average particle size of less than 400 nm;
- b) from 10 to 400 parts of one or more powdery electrode-forming materials;
- c) optionally from 0 to 10 parts of one or more thickeners;
- d) optionally, one or more pH adjusting agents;
- e) from 0 to 10 parts of one or more additives selected from the group consisting of anti-settling agents and surfactants;
- f) optionally from 0 to 5 parts of one or more wetting agents;
- g) an effective amount of one or more fugitive adhesion promoters;
- h) 100 parts water;
- all parts being parts by weight based on 100 parts by weight of water.
A method for making an electrode, comprising the steps of:
- a) forming an aqueous polyvinylidene fluoride (PVDF) dispersion;
- b) admixing the PVDF dispersion with other materials to form an aqueous composition comprising:
- i. 0.2 to 150 parts of polyvinylidene fluoride (PVDF) particles having a weight average particle size of less than 500 nm;
- ii. 10 to 500 parts of one or more powdery electrode-forming materials;
- iii. optionally 0 to 10 parts of one or more thickeners;
- iv. optionally, one or more pH adjusting agents;
- v. optionally 0 to 10 parts of one or more additives selected from the group consisting of anti-settling agents and surfactants;
- vi. optionally from 0 to 5 parts of one or more wetting agents;
- vii. 100 parts water;
- all parts being parts by weight based on 100 parts by weight of water;
- c) forming said aqueous composition into an aqueous-based slurry or paste;
- d) adding an effective amount of a fugitive adhesion promoter to said aqueous-based slurry or paste either prior to forming said aqueous composition into a slurry or paste, or after application of said aqueous-based slurry or paste to at least one surface of an electroconductive substrate;
- e) applying said aqueous-based slurry or paste to at least one surface of an electroconductive substrate to form a coating;
- and
- f) drying said coating,
- wherein said electrode exhibits interconnectivity.
Dependencies are inferred from the claim text.