CORE, BATTERY, AND BATTERY PACK

A core, a battery, and a battery pack are provided. The core includes: an electrode sheet assembly including a plurality of electrode sheets each including a tab; where a plurality of tabs are welded to form a weld imprint area, a height of the tabs after folded is H1, and the height of the weld imprint area is H2; and where the core further has two side surfaces opposite to each other in a thickness direction of the core, a distance between the weld imprint area and one of the side surfaces is D, and a thickness of the core is d; and where 0.42≤arctan((H1−H2)/(d−D))/arctan((H1−H2)/D)≤1.