Battery cell comprising case, electrode terminal, and sealing member, battery comprising the battery cell, and electric apparatus comprising the battery

A battery cell, comprising:

• a case, wherein the case comprises a wall portion, the wall portion having a lead-out hole;
• an electrode terminal, wherein the electrode terminal comprises an insertion portion and a flange portion which are connected to each other in an axial direction of the electrode terminal, the insertion portion being disposed in the lead-out hole, the flange portion being located on a side that is of the insertion portion and that is away from the inside of the case and being at least partially beyond the insertion portion in a radial direction of the electrode terminal, the electrode terminal having a groove portion disposed in the axial direction, and an opening end of the groove portion being located on an outer end face of the flange portion;
• and
• a sealing member, wherein the sealing member comprises a body portion and an adapter portion, the body portion being disposed in the groove portion and configured to seal the groove portion, the adapter portion being disposed at an end that is of the body portion and that faces away from the inside of the case, a radial dimension of the adapter portion being less than a radial dimension of the body portion, an outer end face of the adapter portion protruding from the outer end face of the flange portion and an outer end face of the body portion in the axial direction and being configured to be electrically connected to an external component,
• the adapter portion is electrically connected to an external component by welding, a height difference between the outer end face of the adapter portion and the outer end face of the flange portion is greater than or equal to 0.2 mm in the axial direction,
• wherein the groove portion comprises a first groove section, a second groove section, and a third groove section that are sequentially connected in a direction from the outside of the case to the inside of the case, the first groove section being located in the flange portion, the second groove section being located at least partially in the flange portion, a radial dimension of the first groove section being greater than a radial dimension of the second groove section, a first annular mesa being then formed at a joint between the first groove section and the second groove section, the radial dimension of the second groove section being greater than a radial dimension of the third groove section, a second annular mesa being then formed at a joint between the second groove section and the third groove section, and the body portion being disposed at least partially in the second groove section and supported on the second annular mesa, wherein
• the radial width of the first annular mesa is greater than or equal to 0.2 mm in the radial direction;
• the body portion is fixed to the electrode terminal by welding, and the outer end face of the body portion protrudes from the first annular mesa in the axial direction;
• and
• a height difference between the outer end face of the body portion and the first annular mesa is greater than or equal to 0.1 mm.