Method of producing a self-supported electrode film in a wet process without organic solvent

A method of producing a self-supported electrode film for an electrode in a group of devices for electrochemical energy conversion or devices for electrical energy storage, the group including batteries, electric double layer capacitors, supercapacitors and supercabatteries, fuel cells, and electrolyzers;

• wherein the method is free from organic solvents, wherein the method is automatic and comprises processes in an automated sequence, the processes comprising,
• in a mixing process, providing an aqueous dispersion of a powder mix in an aqueous liquid, the powder mix comprising a content of a first powder, which is a powder of a binder material, and a content of a second powder, which is a powder of an active material for the electrode, wherein the binder material is a polymer with fibrilization capabilities and the binder material has a glass transition temperature and a melting temperature;
• in a separation process after dispersion of the powder mix, separating the powder mix from a portion of the aqueous liquid in the dispersion by a mechanical process for obtaining a liquid-reduced slurry of the powder mix of binder material and active material,
• in an evaporation process, after the separation process, heating the powder mix to a boiling point of the aqueous liquid and causing evaporation of remaining liquid from the dispersion to form a mixture of the binder material and the active material;
• in a kneading process, kneading the mixture in a kneader after evaporation of the aqueous liquid at a temperature above the glass transition temperature of the binder material but below the melting temperature of the binder material for transforming the mixture into a malleable substance by the kneading, and continuing to knead the mixture until fibrillization of the binder material is caused by the kneading;
• after the kneading process, in an extrusion process, extruding the malleable substance, and in a calendering process, calendering the extruded malleable substance by calendering rollers into a film with a predetermined thickness of 10-1000 micrometers, wherein the malleable substance after the kneading process has a temperature that is only below the melting temperature of the binder material for maintaining the fibrillization of the binder material;
• in a cooling stage, cooling the electrode film to a temperature below the glass transition temperature of the binder material.