摘要 |
A lithium ion capacitor includes a positive electrode made of a material capable of reversibly doping and dedoping lithium ions and/or anions; a negative electrode made of a material capable of reversibly doping and dedoping lithium ions; and an electrolytic solution made of an aprotonic organic solvent electrolyte solution of a lithium salt. When the negative electrode and/or positive electrode and a lithium ion supply source are electrochemically brought into contact, lithium ions are doped in a negative electrode and/or positive electrode. A positive electrode potential after the positive electrode and negative electrode are short-circuited is 2.0 V (vs. Li/Li + ) or less. The positive electrode and/or negative electrode has a current collector made of a metal foil that has many holes that penetrate through both sides and have an average diameter of inscribed circles of the through-holes of 100 µm or less. |