Paste for electrochemical device, slurry for electrochemical device electrode, electrode for electrochemical device, and electrochemical device

A paste for an electrochemical device comprising a conductive material, a polymer A, and a dispersion medium, wherein

• the conductive material includes a fibrous conductive material,
• the paste for an electrochemical device contains the conductive material in a proportion of more than 2 mass %,
• the polymer A includes a nitrile group-containing monomer unit and an alkylene structural unit and has a Mooney viscosity (ML1+4, 100° C.) of not less than 70 and not more than 150, and
• the paste for an electrochemical device contains the polymer A in a proportion of more than 50 parts by mass and not more than 200 parts by mass per 100 parts by mass of the conductive material.