Patent ID: 8902566

Claim:
A capacitor, comprising a positive electrode, a negative electrode, and an electrolyte layer arranged between these electrodes, wherein at least one of the electrodes comprises an Al porous body functioning as a current collector, and an electrode material that is held in the Al porous body to polarize the electrolyte, and an oxygen content in a surface of the Al porous body is 3.1% by mass or less, and wherein the positive electrode comprises the Al porous body, and the electrode material that is made mainly of activated carbon, the negative electrode comprises a porous metal for the negative electrode, and a negative-electrode active material that is made mainly of an element that adsorbs Li ions and releases the Li ions, and that is filled into pores in the porous metal for the negative electrode, the electrolyte layer is a combination of a nonaqueous electrolytic solution containing a Li salt, and a separator, and Li ions are chemically or electrochemically adsorbed onto the negative electrode.