A battery cell, comprising: an electrode assembly, comprising a body portion and a first tab, wherein a first size L1 of the body portion in a length direction thereof is greater than a second size L2 of the body portion in a width direction thereof; and the first tab is located on at least one end of the body portion in the width direction, the first tab has a third size L3 in the length direction, and the first size L1, the second size L2, and the third size L3 satisfy 0.5L2≤L3≤L1, wherein the battery cell further comprises: a housing, wherein the electrode assembly is located inside the housing; a first end cap, located on a side of the electrode assembly in the length direction and configured to close a first opening of the housing; a first electrode terminal, disposed on the first end cap; and a first adapting component, configured to connect the first electrode terminal and the first tab, characterized in that the electrode assembly further comprises a second tab with a polarity opposite to that of the first tab, the first tab comprises two first sub-tabs, the two first sub-tabs are respectively located on two ends of the body portion in the width direction, the second tab comprises two second sub-tabs, and the two second sub-tabs are respectively located on two ends of the body portion in the width direction, wherein the first sub-tab and the second sub-tab on a same end of the body portion are spaced apart in the length direction. an electrode assembly, comprising a body portion and a first tab, wherein a first size L1 of the body portion in a length direction thereof is greater than a second size L2 of the body portion in a width direction thereof; and the first tab is located on at least one end of the body portion in the width direction, the first tab has a third size L3 in the length direction, and the first size L1, the second size L2, and the third size L3 satisfy 0.5L2≤L3≤L1, wherein the battery cell further comprises: a housing, wherein the electrode assembly is located inside the housing; a first end cap, located on a side of the electrode assembly in the length direction and configured to close a first opening of the housing; a first electrode terminal, disposed on the first end cap; and a first adapting component, configured to connect the first electrode terminal and the first tab, characterized in that the electrode assembly further comprises a second tab with a polarity opposite to that of the first tab, the first tab comprises two first sub-tabs, the two first sub-tabs are respectively located on two ends of the body portion in the width direction, the second tab comprises two second sub-tabs, and the two second sub-tabs are respectively located on two ends of the body portion in the width direction, wherein the first sub-tab and the second sub-tab on a same end of the body portion are spaced apart in the length direction. a housing, wherein the electrode assembly is located inside the housing; a first end cap, located on a side of the electrode assembly in the length direction and configured to close a first opening of the housing; a first electrode terminal, disposed on the first end cap; and a first adapting component, configured to connect the first electrode terminal and the first tab, characterized in that the electrode assembly further comprises a second tab with a polarity opposite to that of the first tab, the first tab comprises two first sub-tabs, the two first sub-tabs are respectively located on two ends of the body portion in the width direction, the second tab comprises two second sub-tabs, and the two second sub-tabs are respectively located on two ends of the body portion in the width direction, wherein the first sub-tab and the second sub-tab on a same end of the body portion are spaced apart in the length direction.