NOVELTY - A lithium ion capacitor consists of transferable electrolyte, positive electrode, negative electrode and lithium ion. The positive electrode is equipped with current collection material, and contains lithium ion and/or substance which carry an anion as positive electrode active material in a state bound with binder. The negative electrode is equipped with current collection material, and contains substance which carry lithium ion reversibly as negative electrode active material. The lithium ion is electrochemically supported by positive electrode and/or negative electrode.    USE - Lithium ion capacitor. Uses include but are not limited to electric vehicle such as electric-power-assisted bicycle, hybrid electric vehicle, electrical storage apparatus for drive, electric wheel chair, wind-power electricity generation and domestic electrical appliances.    ADVANTAGE - The lithium ion capacitor has high output, high energy density, reliability, voltage withstand property, durability, capacitance, and low resistance.    DETAILED DESCRIPTION - A lithium ion capacitor consists of transferable electrolyte, positive electrode, negative electrode and lithium ion. The positive electrode is equipped with current collection material provided with through-hole which penetrates front and back, and contains lithium ion and/or substance which carry an anion as positive electrode active material in a state bound with binder. The negative electrode is equipped with current collection material provided with through-hole which penetrates front and back, and contains substance which carry lithium ion reversibly as negative electrode active material. The lithium ion is electrochemically supported by positive electrode and/or negative electrode. The binder contains polymer composition containing fluoropolymer (a) (5-20 mass%) and acryl group-containing polymer (b) (80-95) containing structural unit derived from ester group-containing monomer, and is a particulate having number average particle diameter of 0.1-0.4 mu m. The ester group-containing monomer is of formula: CH2=CR1COOR2.    R1=H or methyl;and    R2=1-18C alkyl or cycloalkyl.