Battery cell, method and system for manufacturing a battery cell, battery and electrical device

A battery cell for use in a battery, comprising:

• an electrode assembly, comprising a first tab and a second tab with opposite polarities;
• a casing for accommodating the electrode assembly, wherein the casing comprises a cylinder body and a cover body connected to the cylinder body, the cylinder body is disposed around an outer periphery of the electrode assembly, the cover body is provided with an electrode lead-out hole, and at least part of the cover body is used for electrically connecting a first connecting member of the battery and the first tab;
• and
• an electrode terminal for electrically connecting a second connecting member of the battery and the second tab, wherein the electrode terminal is disposed at the cover body in an insulating manner and installed at the electrode lead-out hole, one of the cover body and the electrode terminal is a positive output pole of the battery cell, and the other is a negative output pole of the battery cell.