Method for manufacturing lithium-ion capacitor

A method for manufacturing a lithium-ion capacitor, comprising:

• preparing a positive electrode by applying a positive electrode material to a current collector;
• preparing a negative electrode by applying a negative electrode material to a current collector;
• providing metallic lithium to one set of an electrode pair made up of the positive electrode, a separator, and the negative electrode which are laminated in this order or to sets of electrode pairs, the sets being laminated, a separator being provided between the respective sets, each of the electrode pairs being made up of the positive electrode, the separator, and the negative electrode which are laminated in this order;
• accommodating, in a container, the electrode pair(s) having the metallic lithium provided thereto;
• freeze-drying the electrode pair(s) having the metallic lithium provided thereto and accommodated in the container;
• injecting an electrolyte solution into the container in which the electrode pair(s) having the metallic lithium provided thereto has been accommodated and freeze-dried;
• and
• sealing the container into which the electrolyte solution has been injected.