ELECTRICITY STORAGE DEVICE

An electricity storage device includes an electrode assembly such that positive and negative electrodes are alternately stacked in which the positive and negative electrodes are insulated from one another. Tab groups each including positive or negative electrode tabs bundled in the stacking direction of the electrode assembly are provided on an edge portion of the electrode assembly. The tab groups each include a first bent portion and an extending portion, which extends from the first bent portion in the stacking direction of the electrode assembly. The tab groups also each include a second bent portion at which the tab group is curved or bent such that the distal end in the extending direction of the tab that is located at an outermost position of the first bent portion is positioned between the electrode assembly and the tab that is located at an innermost position of the first bent portion.