Lithium Ion Capacitor and Layered Member for Lithium Ion Capacitor

A lithium ion capacitor comprising:

• an electrode group including a positive electrode, a negative electrode, and a separator, the positive electrode having a positive current collector and an active material mixture supported on the positive current collector and the negative electrode having a negative current collector and an active material mixture supported on the negative current collector;
• a non-aqueous electrolyte;
• a container for housing the electrode group and the non-aqueous electrolyte;
• and
• a layered member as a lithium ion source disposed in or adjacent to the electrode group while being electrically insulated from the positive electrode, the layered member comprising:
• two metal foils each including a portion in which a large number of through holes are formed and a portion in which through holes are not formed and which is provided adjacent to the portion with the through holes;
• and
• lithium metal having a thin plate shape and sandwiched between the two metal foils to contact the portions with the through holes of the two metal foils,
• wherein only the metal foils are left in the layered member with the lithium metal occluded by a negative active material in the active material mixture of the negative electrode.