Method for preparing nano-silver powder and application in preparation of electrically conductive ink of the nano-silver powder and electrically conductive ink

An electrically conductive ink consisting of a nano-silver powder, optionally at least one adhesive, at least one weak solvent and optionally at least one additive, wherein the nano-silver powder is in a content of 10% to 80% by weight, the at least one additive is in a content of 0% to 20% by weight, the at least one weak solvent is in a content of 15% to 90% by weight, and the at least one additive is in a content of 0% to 75%, and the percent by weight for the nano-silver powder, the at least one adhesive, the at least one weak solvent, and the at least one additive, are based on the weight of the electrically conductive ink;

• the at least one weak solvent is one or more selected from the group consisting of ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, di-propylene glycol monomethyl ether acetate, di-propylene glycol monoethyl ether acetate, di-propylene glycol monobutyl ether acetate, propylene glycol monoethyl ether acetate, di-ethylene glycol monomethyl ether acetate, di-ethylene glycol monoethyl ether acetate, di-ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, propylene glycol monophenyl ether acetate, di-glycol monobutyl ether acetate, di-propylene glycol monomethyl ether, tri-propylene glycol monomethyl ether, terpineol, tri-ethylene glycol monomethyl ether, tri-ethylene glycol monobutyl ether, di-ethylene glycol monomethyl ether, and di-ethylene glycol monobutyl ether;
• and the nano-silver powder is dissoluble in both water and weak solvents;
• the nano-silver particles in the nano-silver powder have a particle size of 20 nm to 90 nm, the surfaces of the nano-silver particles are coated with disperser, and wherein the disperser is an acrylic-modified polyurethane-based disperser.