Abstract: A method for manufacturing positive electrode active material includes: forming a fluorine-based coat film on a surface of a positive electrode active material by subjecting the positive electrode active material to a fluorine treatment; and forming a fluorine-oxygen-containing active material layer that contains fluorine and oxygen on the surface of the positive electrode active material by firing the fluorine-based coat film under an oxygen atmosphere.

Abstract: A power storage device includes a fuel cell (33), a battery holder (1) and an end plate (40) for sandwiching and binding the fuel cell, and an interposed member (11) disposed between the end plate (40) and the fuel cell (33). The battery holder (1) and the end plate (40) are made of resin, and have a positive coefficient of thermal expansion at a temperature lower than a predetermined temperature. The interposed member (11) is formed to have a substantially negative coefficient of thermal expansion at a temperature lower than the predetermined temperature.

Abstract: An electroactive material and a method of manufacturing the same is provided, in which the primary component of the electroactive material is a metal boron oxide complex, and the electroactive material exhibits excellent charge/discharge characteristics. The electroactive material of the present invention is primarily composed of an amorphous metal complex represented by the general formula M2-2xB2xO3. M is one or two or more metal elements selected from the transition metal elements, e.g., Fe or V. In addition, x is 0<×<1, e.g., ½. This type of electroactive material can be manufactured by amorphizing the metal complex represented by the general formula M2-2xB2xO3 by means of a mechanical milling method. In addition, the electroactive material can be manufactured by rapidly cooling and solidifying a mixture containing an oxide in which M is a constituent metal element and a boron oxide from the melted state.