Aqueous polyvinylidene fluoride composition

摘要

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.

主权项

1. An aqueous binder dispersion composition comprising;
a) from 0.2 to 150 parts fluoropolymers binder particles free of fluorosurfactant having a weight average particle size of less than 500 nm, wherein said fluoropolymer is a polyvinylidene fluoride (PVDF) homopolymer or copolymer comprising at least 70 mole percent of vinylidene fluoride units; b) from 10 to 500 parts of one or more powdery electrode-forming materials, wherein said powdery electrode material is selected from the group consisting of salts of lithium and at least one transition metal, a carbonaceous material or nano-titanate; 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) from 1-50 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.