Abstract: A lithium-ion capacitor excellent in durability, which has high energy density and high capacity retention ratio when the capacitor is charged and discharged at a high load, is disclosed. The lithium-ion capacitor includes a positive electrode, a negative electrode and an aprotic organic solvent of a lithium salt as an electrolyte solution. In the lithium-ion capacitor, a positive electrode active material allows lithium ions and/or anions to be doped thereinto and de-doped therefrom, and a negative electrode active material allows lithium ions to be doped thereinto and de-doped therefrom. At least one of the negative electrode and the positive electrode is pre-doped with lithium ions so that after the positive electrode and the negative electrode are shortcircuited, a potential of the positive electrode is 2 V (relative to Li/Li+) or lower. A thickness of a positive electrode layer of the positive electrode is within a range from 18 to 108 ?m.

Abstract: An electric storage device has positive and negative electrode systems. The positive electrode system includes a positive electrode having a current collector and a positive-electrode mixture layer. The negative electrode system includes a negative electrode having a current collector and a negative-electrode mixture layer. The negative electrode system further includes a first negative-electrode mixture layer and a second negative-electrode mixture layer, which are connected to each other and which include at least one different material or have different material composition ratios. The first negative-electrode mixture layer and the second negative-electrode mixture layer have different charge/discharge characteristics. A through-hole is formed in the current collector arranged between the first negative-electrode mixture layer and the second negative-electrode mixture layer.

Abstract: The invention provides a negative electrode material for use with a lithium-ion capacitor, which is high in energy density, output density and excellent in durability. When graphite of which an average distance between 002 lattice planes thereof is within a range from 0.335 nm to 0.337 nm is used for an active material of a negative electrode of a lithium-ion capacitor, the energy density of the capacitor is increased. The output characteristic and the cycle durability can be improved when D10, D50 and D90 are set within predetermined ranges.

Abstract: A negative electrode 15 includes a negative-electrode current collector 16 provided with a large number of through-holes 16a and a negative-electrode mixture layer 17 applied thereon. Positive electrodes 13 and 14 are arranged so as to sandwich the negative electrode 15. A thin positive-electrode mixture layer 20 having a high output characteristic is provided to the positive electrode 13, and a thick positive-electrode mixture layer 22 having a high capacity is provided to the other positive electrode 14. Since these positive electrodes 13 and 14 having different charging/discharging characteristics are provided, an energy density and an output density can be enhanced. Ions can move between the positive-electrode mixture layers 20 and 22 via the through-holes 16a of the negative-electrode current collector 16, whereby a variation in the potential of the positive electrodes 13 and 14 can be canceled. Therefore, the durability of the electric storage device 10 can be ensured.

Abstract: A positive electrode 13 includes a positive-electrode current collector 16 provided with a large number of through-holes 16a and a positive-electrode mixture layer 17 applied thereon. Negative electrodes 14 and 15 are arranged so as to sandwich the positive electrode 13. A negative-electrode mixture layer 20 of the negative electrode 14 contains a hard carbon having a high capacity characteristic, while a negative-electrode mixture layer 22 of the negative electrode 15 contains a PAS having a high output characteristic. Since the negative electrodes 14 and 15, each having a different charge/discharge characteristic, are provided, an energy density and an output density of the electric storage device 10 can be enhanced.

Abstract: The invention provides a negative electrode material for use with a lithium-ion capacitor, which is high in energy density, output density and excellent in durability. When graphite of which an average distance between 002 lattice planes thereof is within a range from 0.335 nm to 0.337 nm is used for an active material of a negative electrode of a lithium-ion capacitor, the energy density of the capacitor is increased. The output characteristic and the cycle durability can be improved when D10, D50 and D90 are set within predetermined ranges.

Abstract: A lithium-ion capacitor excellent in durability, which has high energy density and high capacity retention ratio when the capacitor is charged and discharged at a high load, is disclosed. The lithium-ion capacitor includes a positive electrode, a negative electrode and an aprotic organic solvent of a lithium salt as an electrolyte solution. In the lithium-ion capacitor, a positive electrode active material allows lithium ions and/or anions to be doped thereinto and de-doped therefrom, and a negative electrode active material allows lithium ions to be doped thereinto and de-doped therefrom. At least one of the negative electrode and the positive electrode is pre-doped with lithium ions so that after the positive electrode and the negative electrode are shortcircuited, a potential of the positive electrode is 2 V (relative to Li/Li+) or lower. A thickness of a positive electrode layer of the positive electrode is within a range from 18 to 108 ?m.