Abstract: A viologen compound is a crystalline compound including a heterocyclic moiety in which a carboxylate of an alkali metal is bound directly or indirectly to both ends of a basic skeleton containing 4,4?-bipyridinium and an anionic moiety that pairs with 4,4?-bipyridinium. The viologen compound can be used, for example, as a negative electrode active material for an electricity storage device including a negative electrode containing the negative electrode active material, a positive electrode containing a positive electrode active material capable of giving and receiving anions, and an ion-conducting medium that is disposed between the positive electrode and the negative electrode and conducts anions.

Abstract: There is provided a skin-material fixing clip for connecting a skin material with a cushion material and provided with a locking section and a hook. The hook is provided with an extension portion extending downward from the locking section and a claw-shaped portion extending laterally from a distal end of the extension portion. The locking section is provided with a wire guide piece. A groove portion surrounded by the claw-shaped portion and the extension portion defines a wire holding space. Parts of the wire guide piece and the claw-shaped portion facing the wire insertion opening defines guide surfaces. The distal end portion of the wire guide piece and the distal end portion of the claw-shaped portion are provided to be spaced from each other along a direction parallel to an extending direction of the groove portion.

Abstract: A viologen compound is a crystalline compound including a heterocyclic moiety in which a carboxylate of an alkali metal is bound directly or indirectly to both ends of a basic skeleton containing 4,4?-bipyridinium and an anionic moiety that pairs with 4,4?-bipyridinium. The viologen compound can be used, for example, as a negative electrode active material for an electricity storage device including a negative electrode containing the negative electrode active material, a positive electrode containing a positive electrode active material capable of giving and receiving anions, and an ion-conducting medium that is disposed between the positive electrode and the negative electrode and conducts anions.

Abstract: There is provided a skin-material fixing clip for connecting a skin material with a cushion material and provided with a locking section and a hook. The hook is provided with an extension portion extending downward from the locking section and a claw-shaped portion extending laterally from a distal end of the extension portion. The locking section is provided with a wire guide piece. A groove portion surrounded by the claw-shaped portion and the extension portion defines a wire holding space. Parts of the wire guide piece and the claw-shaped portion facing the wire insertion opening defines guide surfaces. The distal end portion of the wire guide piece and the distal end portion of the claw-shaped portion are provided to be spaced from each other along a direction parallel to an extending direction of the groove portion.