| abstract |
A power storage device includes an electricity storage element, a case , and a sealing member. The sealing member includes an elastic member. The elastic member contains an elastic polymer and a hindered phenol compound. The hindered phenol compound having a phenol skeleton includes a first hindered group and a second hindered group. The first hindered group is bonded to a first substitution site of the phenol skeleton, and the second. hindered group is bonded to a second substitution site of the phenol skeleton. Each of the first substitution site and second substitution site is adjacent to a substitution site of the phenol skeleton to which a phenolic hydroxy group is bonded. One of one or more tertiary carbon atoms in the first hindered group and one of one or more tertiary carbon atoms in the second. hindered group are bonded to the first substitution site and the second substitution site, respectively. |