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

A battery cell, comprising:

• a case having an opening;
• an electrode assembly accommodated in the case;
• an end cover covering the opening and sealed and connected to the case;
• and
• a current collecting member accommodated in the case and located on a side of the electrode assembly facing the end cover, wherein the current collecting member is configured to connect the case and the electrode assembly, so that the electrode assembly is electrically connected to the case;
• and
• wherein the electrode assembly comprises a positive electrode tab and a negative electrode tab, the positive electrode tab being located at one end of the electrode assembly and the negative electrode tab being located at the other end of the electrode assembly;
• and
• wherein the case being provided with an electrode terminal at an end away from the end cover, the electrode terminal is insulated from the case and electrically connected to the positive electrode tab;
• wherein the material of the end cover is the same as the material of the case;
• and
• wherein the battery cell further comprises a sealing member;
• the end cover and the case are sealed and connected through the sealing member;
• and
• wherein the sealing member is configured to insulate and isolate the case from the end cover,
• wherein a first position-limit portion is protruded from an inner side surface of the case, and the first position-limit portion is used for limiting the end cover from moving in a direction facing the electrode assembly;
• and
• wherein the current collecting member comprises:
• a body part configured to connect to the electrode assembly, the body part abuts against a side of the first position-limit portion facing the electrode assembly, and the first position-limit portion is used for limiting the body part from leaving the case in a direction away from the electrode assembly;
• and
• a first connecting portion connected to the body part, the first connecting portion at least partially extending to an inner peripheral side of the first position-limit portion, and the first connecting portion being welded to the first position-limit portion, wherein the first connecting portion is a convex portion extending from the body part in a thickness direction of the end cover away from the electrode assembly, and the convex portion is used for forming a positioning fit with an inner peripheral surface of the first position-limit portion, the convex portion has an inner peripheral surface facing the electrode assembly and an outer peripheral surface away from the electrode assembly, the inner peripheral surface and the outer peripheral surface are arranged on two opposite sides of the convex portion in a thickness direction of the convex portion, the outer peripheral surface of the convex portion contacts the inner peripheral surface of the first position-limit portion to prevent the convex portion from shaking in a direction perpendicular to the thickness direction of the end cover, a welded joint is formed between the outer peripheral surface of the first connecting portion and the inner peripheral surface of the first position-limit portion.