POWER STORAGE ELEMENT

PROBLEM TO BE SOLVED: To provide a power storage element which maintains airtightness over a long term.SOLUTION: A power storage element 10 includes: a terminal (a positive electrode terminal 200) provided in a container 100; and a collector (a positive electrode collector 120) electrically connected to the terminal. The power storage element 10 includes a sealing member (a positive electrode first sealing member) disposed between the terminal or the collector and the container 100. The sealing member has annular parts 155, 156 which surround a shaft part 220 of the terminal and are disposed between the terminal or the collector and the container 100. From among the annular parts 155, 156, at least one annular part 155 and the other annular part 156 are formed by different materials.SELECTED DRAWING: Figure 3 【課題】長期にわたって気密性を維持することのできる蓄電素子を提供する。【解決手段】容器１００に設けられた端子（正極端子２００）と、端子に電気的に接続される集電体（正極集電体１２０）とを備える蓄電素子１０である。蓄電素子１０は、端子又は集電体と容器１００との間に配置された封止部材（正極第１封止部材）を備える。封止部材は、端子の軸部２２０を囲んで、端子又は集電体と容器１００との間に介在する環状部１５５，１５６を複数有する。複数の環状部１５５，１５６のうち、少なくとも１つの環状部１５５と、他の環状部１５６とが異なる材料により形成されている。【選択図】図３