Patent ID: 9559382
Date: 2017-01-31
CPC Classifications: H01M,Y02E,Y02P

Claim:
1. A nonaqueous electrolyte secondary battery comprising: a flat winding electrode assembly formed by winding a positive electrode having a rectangular shape and a negative electrode having a rectangular shape with a separator having a rectangular shape and being interposed therebetween; and an outer body storing the flat winding electrode assembly and a nonaqueous electrolyte, the flat winding electrode assembly including a positive electrode substrate exposed portion wound on one end and a negative electrode substrate exposed portion wound on the other end, the positive electrode substrate exposed portion having a melting area of 2.7 mm the negative electrode substrate exposed portion having a melting area of 1.8 mm the melting area of the positive electrode substrate exposed portion being greater than the melting area of the negative electrode substrate exposed portion, the winding number of the wound positive electrode substrate exposed portion being 30 or more, and the winding number of the wound negative electrode substrate exposed portion being 30 or more, the wound positive electrode substrate exposed portion having an outermost surface welded and connected with the positive electrode collector, and the wound negative electrode substrate exposed portion having an outermost surface welded and connected with the negative electrode collector, the nonaqueous electrolyte containing a lithium salt having an oxalate complex as an anion at the time of making the nonaqueous electrolyte second battery, all of the layers of the positive electrode substrate exposed portion being melted at the welded connection portion between the positive electrode substrate exposed portion and the positive electrode collector to be welded and connected to the positive electrode collector, all of the layers of the negative electrode substrate exposed portion being melted at the welded connection portion between the negative electrode substrate exposed portion and the negative electrode collector to be welded and connected to the negative electrode collector, the positive electrode collector is formed by using aluminum or an aluminum alloy, the positive electrode substrate exposed portion is formed by using aluminum or an aluminum alloy, the negative electrode collector is formed by using copper or a copper alloy, and the negative electrode substrate exposed portion is formed by using copper or a copper alloy.