Electrochemical device and method for manufacturing same

A method for manufacturing an electrochemical device including a positive electrode having a positive electrode material layer containing a conductive polymer doped with a first anion and a second anion, a negative electrode having a negative electrode material layer storing and releasing lithium ions, and a nonaqueous electrolytic solution having lithium ionic conductivity, the electrochemical device being charged and discharged by making the second anion be doped in or dedoped from the conductive polymer, the method comprising:

• a step of forming the positive electrode;
• a step of forming the negative electrode;
• and
• a step of immersing the positive electrode and the negative electrode in a nonaqueous electrolytic solution,
• wherein:
• the step of forming a positive electrode includes a step of forming the conductive polymer doped with the first anion by polymerizing a polymerizable compound that is a raw material of the conductive polymer in a first solution containing a first anion,
• the nonaqueous electrolytic solution contains a second anion that is more easily dedoped from the conductive polymer than the first anion, and
• the step of immersing the positive electrode and the negative electrode in the nonaqueous electrolytic solution includes a step of doping the second anion in the conductive polymer doped with the first anion in the nonaqueous electrolytic solution, and
• the step of forming the conductive polymer doped with the first anion includes a step of removing part of the first anion from the conductive polymer doped with the first anion prior to the step of doping the second anion in the conductive polymer so that a number of moles M1 of the first anion and a number of moles M2 of the second anion respectively doped in the conductive polymer satisfy a relationship of M1<M2 at an end period of charge of the electrochemical device, and a number of moles M3 of the first anion and a number of moles M4 of the second anion respectively doped in the conductive polymer satisfy a relationship of M3>M4 at an end period of discharge of the electrochemical device.