Abstract: A main object of the present disclosure is to provide an active material wherein an expansion upon intercalation of a metal ion such as a Li ion is suppressed. The present disclosure achieves the object by providing an active material comprising a silicon clathrate type crystal phase, and the active material includes a Na element, a Si element and a M element that is a metal element with an ion radius larger than the Si element, and a proportion of the M element to a total of the Si element and the M element is 0.1 atm % or more and 5 atm % or less.

Abstract: A main object of the present disclosure is to provide an active material wherein a volume variation due to charge/discharge is small. The present disclosure achieves the object by providing an active material comprising a silicon clathrate II type crystal phase, and having a composition represented by NaxSi136, wherein 1.98<x<2.54.

Abstract: A fuel tank manufacturing apparatus for a fuel tank, the fuel tank having therein a built-in component with a head portion, a neck portion, and a shoulder portion, and having the built-in component anchored to a tank body with a part of a parison wrapped around the neck portion during molding the tank body, includes: a pair of molding dies to have the parison transferred to the built-in component by blow molding; and shaping devices respectively provided in the pair of molding dies, wherein the shaping devices each include: an end surface to contact the parison; a recess provided in the end surface to receive the head portion and the neck portion and covered by the shoulder portion during molding; and an air hole provided in an area of a bottom surface of the recess corresponding to the head portion through which air pressure is applied toward the head portion.

Abstract: A fuel tank manufacturing apparatus for a fuel tank, the fuel tank having therein a built-in component with a head portion, a neck portion, and a shoulder portion, and having the built-in component anchored to a tank body with a part of a parison wrapped around the neck portion during molding the tank body, includes: a pair of molding dies to have the parison transferred to the built-in component by blow molding; and shaping devices respectively provided in the pair of molding dies, wherein the shaping devices each include: an end surface to contact the parison; a recess provided in the end surface to receive the head portion and the neck portion and covered by the shoulder portion during molding; and an air hole provided in an area of a bottom surface of the recess corresponding to the head portion through which air pressure is applied toward the head portion.