| abstract |
An excellent lithium ion capacitor having high energy density and high output density, high withstand voltage, and high durability is provided. A positive electrode made of a material capable of reversibly supporting lithium ions and / or anions and a negative electrode made of a material capable of reversibly supporting lithium ions are provided. A lithium ion capacitor comprising a conductive organic solvent electrolyte solution, wherein (a) the negative electrode active material is non-graphitizable carbon having a hydrogen atom / carbon atom number ratio of 0 or more and less than 0.05; ) The negative electrode and / or the positive electrode are preliminarily doped with lithium ions so that the negative electrode potential when discharged to half the cell charge voltage is 0.15 V or less of the lithium metal potential. Lithium ion capacitor characterized by [Selection figure] None |