Battery and battery manufacturing method

摘要

A battery having a bundle of electrodes and separator which is made by winding a positive-electrode plate and a negative-electrode plate together with a seperator therebetween, one of the positive- and negative-electrode plates being electrically connected to a power collecting body, the power collecting body being provided in and welded to an outer package can, wherein a welding portion of the outer package can and the power collecting body comprises a first layer and a second layer which are stacked in a thickness direction of the outer package can at the welding portion, and the second layer is in contact with a surface of the first layer and includes crystal grains that are minuter than crystal grains included in the first layer.