Patent ID: 7166387

Claim:
A thin battery comprising: a battery outer casing; an electricity-generating element disposed inside the battery outer casing, the electricity-generating element including a positive electrode plate, a negative electrode plate, and a separator that are stacked together; a first electrode terminal electrically connected to the electricity-generating element; and a second electrode terminal electrically connected to the electricity-generating element and extending outwardly from the battery outer casing, the second electrode terminal including a base portion having a first material strength and a tip portion with a strength transition point formed between the base and tip portions at a location spaced from the battery outer casing, the tip portion having a free end with an entire area of the tip portion from the strength transition point to the free end having a second material strength that is lower than the first material strength of the base portion, the base portion and the tip portion being formed as a one-piece unitary member, the first and second material strengths being formed by the one-piece unitary member without an additional material.