Electricity storage device

An electricity storage device comprising:

• an electrode assembly;
• a case that accommodates the electrode assembly;
• a safety valve arranged in the case, wherein the safety valve opens and discharges gas out of the case when an inner pressure of the case exceeds a release pressure;
• and
• an opposing member arranged in the case opposing the safety valve, wherein the opposing member includes a flow passage for the gas, and wherein
• the electrode assembly is formed by stacking electrodes and a separator,
• ends of the electrodes respectively include tabs,
• a conductor joined with the tabs is arranged between the tabs and an inner surface of the case,
• the opposing member is plate-shaped and located between the conductor and the inner surface of the case on which the safety valve is arranged,
• the electrodes include a first electrode and a second electrode having different polarities,
• the tabs include a first tab arranged on the end of the first electrode and a second tab arranged on the end of the second electrode,
• the conductor is one of a first conductor joined with the first tab and a second conductor joined with the second tab,
• the first conductor and the second conductor are spaced apart in a direction orthogonal to both of an opposing direction of the safety valve and the opposing member and a stacking direction of the electrode assembly,
• the opposing member includes a projection arranged on a surface of the opposing member that is close to the conductor,
• at least a portion of the projection is located between the first conductor and the second conductor
• the second conductor is plate-shaped and includes a thick portion and a thin portion having different thicknesses,
• the thin portion and the second tab are welded, and
• a portion of the projection overlaps the thin portion as viewed from the opposing direction.