Abstract: This lithium ion capacitor results from housing an electrode laminate body, which comprises a positive electrode, a negative electrode, and a separator, and a non-aqueous electrolyte, which contains a lithium-ion-containing electrolyte, in an external body, wherein the negative electrode has a negative electrode current collector and a negative electrode active material layer containing a negative electrode active material that can occlude and release lithium ions on one or both surfaces of the negative electrode current collector, and the following (i) to (iii) are all satisfied: (i) the negative electrode active material is a carbon composite material containing carbon black and a carbonaceous material; (ii) the negative electrode is doped with lithium ion at between 1,050 mAh/g and 2,500 mAh/g, inclusive, per unit mass of the negative electrode active material; and (iii) the thickness of the negative electrode active material layer is between 10 ?m and 60 ?m, inclusive, per side.

Abstract: Provided is a nonaqueous lithium storage element which is obtained by housing an electrode body and a nonaqueous electrolyte solution containing a lithium salt in an outer case, said electrode body being composed of a negative electrode that is composed of a negative electrode collector and a negative electrode active material layer laminated on one or both surfaces of the negative electrode collector, a positive electrode that is composed of a positive electrode collector and a positive electrode active material layer laminated on one or both surfaces of the positive electrode collector, and a separator.