Power storage device cell, manufacturing method therefor, and electric storage device

A power storage device cell comprising:

• a first electrode in which a first electrode layer including activated-carbon fine particles is formed on one side of a first collector foil;
• a second electrode in which a second electrode layer including lithium-containing metal compound particles is formed on one side of a second collector foil;
• a third electrode in which a third electrode layer is formed on at least one side of a third collector foil;
• a first separator formed of a porous insulative film;
• and
• a second separator formed of a porous insulative film, wherein
• penetration holes are formed in the third collector foil;
• a capacitor whose negative electrode is the third electrode is formed by inserting the first separator between the first electrode layer and one side of the third electrode;
• a lithium ion battery whose negative electrode common to the capacitor is the third electrode is formed by inserting the second separator between the second electrode layer and the other side of the third electrode;
• the first electrode and the second electrode are directly connected;
• the third electrode layer is formed of a carbon-based material in which graphite particles and hard carbon particles are mixed, and the proportion of the hard carbon particles in the carbon-based material is from 5% by weight to 70% by weight;
• and
• portions of the third electrode layer are provided on both sides of the third collector foil, and the proportion of hard carbon particles included in the third electrode layer at the side of the first separator is higher than the proportion of hard carbon particles included in the third electrode layer at the side of the second separator.