Composition for electrochemical device and method of producing same, binder composition for electrochemical device, conductive material dispersion liquid for electrochemical device, slurry for electrochemical device electrode, electrode for electrochemical device, and electrochemical device

A method of producing a composition for an electrochemical device that contains a polymer including a nitrile group-containing monomer unit and either or both of a conjugated diene monomer unit and an alkylene structural unit, comprising:

• modifying at least one terminal of a polymer including a nitrile group-containing monomer unit and either or both of a conjugated diene monomer unit and an alkylene structural unit using a compound derived from formula (1) or (2), shown below,
• where, in formulae (1) and (2),
• R0 is an alkyl group having a carbon number of 10 or less or a hydrogen atom,
• X is a carboxyl group, a trimethoxysilyl group, an alkyl group having a carbon number of 10 or less that includes a substituent R1, a phenyl group that includes a substituent R2, CO(OCH2CH2)n1OR3, or CO(OCH2CH2)n2R4, where R1 and R2 are, independently of each other, a hydroxyl group, a carboxyl group, an amino group, a hydroxyphenyl group, or a methoxyphenyl group, R3 and R4 are, independently of each other, an alkyl group having a carbon number of 10 or less, a phosphate group, a sulfo group, or a phenyl group, and n1 and n2 are, independently of each other, an integer of not less than 1 and not more than 100,
• Y is a carboxyl group or an alkyl group having a carbon number of 2 or less that optionally includes a substituent R5, where R5 is a hydroxyl group or a carboxyl group, and
• Z is a carboxyl group or an alkyl group having a carbon number of 10 or less that includes a substituent R5, where R5 is a hydroxyl group or a carboxyl group;
• and
• purifying a composition obtained through the modifying such that concentration of divalent or higher-valent metal ions is not less than 5 mass ppm and not more than 4,000 mass ppm.