Battery and seal unit

A seal unit comprising:

• a seal member comprising a first surface and a second surface as a back of the first surface, wherein the seal member comprises a rising part comprising a tip projected from the second surface, and a through hole passing through the seal member from the first surface to the tip of the rising part, and the through hole comprises a taper part having a diameter that reduces with increasing proximity to the tip of the rising part;
• a gasket comprising a through hole;
• and
• a terminal comprising a first end part and a second end part, wherein the terminal comprises a main part extending to an axial direction toward the second end part from the first end part, and the main part comprises a diameter-reduction part between the first end part and the second end part, the diameter-reduction part having a diameter that reduces with increasing proximity to the second end part,
• wherein at least a part of the gasket is located in the taper part of the through hole of the seal member,
• at least a part of the diameter reduction part of the main part of the terminal is located in the through hole of the gasket,
• the at least a part of the gasket is sandwiched between the taper part of the seal member and the diameter-reduction part of the terminal, and
• an inclination angle of the taper part of the seal member to the axial direction of the main part of the terminal is larger than an inclination angle of the diameter-reduction part to the axial direction.