| US 7,563,536 B2 | ||
| Prismatic sealed secondary battery having a case made of metal materials and method for manufacturing the same | ||
| Yasuhiro Yamauchi, Tsuna-gun (Japan); and Tomokazu Yamanaka, Sumoto (Japan) | ||
| Assigned to Sanyo Electric Co., Ltd., Moriguchi-shi (Japan) | ||
| Filed on Nov. 12, 2004, as Appl. No. 10/986,658. | ||
| Claims priority of application No. 2003-385767 (JP), filed on Nov. 14, 2003. | ||
| Prior Publication US 2005/0106453 A1, May 19, 2005 | ||
| Int. Cl. H01M 2/02 (2006.01) | ||
| U.S. Cl. 429—171 [429/163] | 7 Claims |
| 1. A prismatic sealed secondary battery, comprising:
an electrode assembly including a positive electrode, and a negative electrode, and a separator sandwiched between the positive
electrode and the negative electrode;
a case which is made of a metal material formed in one or more plates, has a prismatic tubular shape with four lateral planes,
one open end, and one closed end, and has an internal space in which the electrode assembly is housed, the four lateral planes,
each of which has a plate thickness, being composed of two main planes and two secondary planes, the main planes being laid
along a direction intersecting thickness of the positive electrode or the negative electrode; and
a sealing cap joined with the open end to seal the internal space, wherein
on an area on at least one of the main planes, one or more linear heat strain signatures formed as a result of an application
of heat are created, the area being apart from outer lines of the at least one of the main planes,
linear portion formed within each of the linear heat strain signatures is, on cross section, fanned out inwardly toward the
plate thickness from a center of a width of the linear heat strain signature, and is composed of a recrystallized structure,
and
one or more depressions are formed, surrounding the linear heat strain signatures.
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