Aqueous coating liquid for an electrode plate, electrode plate for an electrical storage device, method for manufacturing an electrode plate for an electrical storage device, and electrical storage device

A water-based coating formulation for an electrode plate of an electricity storage device, said water-based coating formulation being adapted to form a coating film layer on the electrode plate, comprising:

• in a water-based medium comprising at least water as a polar solvent,
• (1) a resin binder, which is at least one resin having a saponification degree of 40% or higher and is selected from the group consisting of unmodified polyvinyl alcohol, modified polyvinyl alcohols, unmodified ethylene-vinyl alcohol copolymer, and modified ethylene-vinyl alcohol copolymers;
• (2) an electrically conductive material;
• (3) at least one polybasic acid selected from the group consisting of 1,2,3,4-butanetetracarboxylic acid, pyromellitic acid, citric acid, ethylenediaminetetraacetic acid, 1,2,3-propanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, trimellitic acid, 1,4,5,8-naphthalenetetracarboxylic acid, and 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, or an acid anhydride thereof;
• and
• (4) at least one additive resin selected from the group consisting of a copolymers of vinylpyrrolidone, which have the vinylpyrrolidone as an essential constituent monomer and chitosan derivatives,
• wherein the copolymers of the vinylpyrrolidone are a vinylpyrrolidone/vinyl acetate/vinyl propionate copolymer, a vinyl acetate/crotonic acid/vinylpyrrolidone copolymer, a vinylpyrrolidone/acrylate copolymer, a quaternized product of vinylpyrrolidone/dimethylaminoethyl methacrylate, a methylvinylimidazolium chloride/vinylpyrrolidone copolymer, a vinylpyrrolidone/vinyl acetate copolymer, a vinylpyrrolidone/dimethylaminoethyl methacrylate copolymer, a vinylcaprolactam/vinylpyrrolidone/dimethylaminoethyl methacrylate copolymer, a styrene/vinylpyrrolidone copolymer, and a vinylpyrrolidone/hexadecene copolymer, and
• wherein the chitosan derivatives are hydroxyethyl chitosan, hydroxypropyl chitosan, hydroxybutyl chitosan, hydroxybutyl hydroxypropyl chitosan, carboxymethyl chitosan, succinyl chitosan, glycerylated chitosan, and cationized chitosan,
• wherein a ratio of the components of (1), (2), and (3) in the coating formulation is the resin binder (1) in an amount from 0.1 to 3 parts by mass and the polybasic acid or the acid anhydride thereof (3) in an amount from 0.01 to 6 parts by mass, both, relative to 1 part by mass of the electrically conductive material (2), and
• the coating formulation has a solid content from 0.02 mass % to 40 mass %.