A method and associated device for joining a battery cell tab to a plurality of foils associated with a plurality of electrodes of a battery cell are described. This includes arranging the plurality of foils in a stack, and joining, via a first joining device, the plurality of foils, wherein the first joining device defines a joining region. A portion of the battery cell tab is arranged on the plurality of foils, and joined, via a second joining device, to the plurality of foils. The second joining device generates a weld joint that is encompassed within the joining region defined by the first joining device. In doing so, weld quality and strength of internal welds in a battery cell may be improved by reducing the occurrence of porosities and cracks in the foil/tab weld joints.

A method and associated device for joining a battery cell tab to a plurality of foils associated with a plurality of electrodes of a battery cell are described. This includes arranging the plurality of foils in a stack, and joining, via a first joining device, the plurality of foils, wherein the first joining device defines a joining region. A portion of the battery cell tab is arranged on the plurality of foils, and joined, via a second joining device, to the plurality of foils. The second joining device generates a weld joint that is encompassed within the joining region defined by the first joining device. In doing so, weld quality and strength of internal welds in a battery cell may be improved by reducing the occurrence of porosities and cracks in the foil/tab weld joints.

An electrochemical apparatus includes a housing, an electrode assembly disposed inside the housing, a first tab group, and a first adapting piece electrically connected to the first tab group and extending out from the housing. The electrode assembly is configured to be a winding structure including a first electrode plate. The first tab group includes M first tabs connected to the first electrode plate. A thickness direction of the electrode assembly is defined as a first direction. In the first direction, the electrode assembly includes N layers of the first electrode plate, N being greater than M. The M first tabs are each connected to the first electrode plate. A plane passing through a winding center axis of the electrode assembly and perpendicular to the first direction is defined as a winding center plane. The M first tabs are disposed on two sides of the winding center plane.

An electrochemical apparatus includes a housing, an electrode assembly disposed inside the housing, a first tab group, and a first adapting piece electrically connected to the first tab group and extending out from the housing. The electrode assembly is configured to be a winding structure including a first electrode plate. The first tab group includes M first tabs connected to the first electrode plate. A thickness direction of the electrode assembly is defined as a first direction. In the first direction, the electrode assembly includes N layers of the first electrode plate, N being greater than M. The M first tabs are each connected to the first electrode plate. A plane passing through a winding center axis of the electrode assembly and perpendicular to the first direction is defined as a winding center plane. The M first tabs are disposed on two sides of the winding center plane.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, a separator located between the first electrode and the second electrode, a first electrode tab extended from the first electrode, and a second electrode tab extended from the second electrode; a case connected to the first electrode tab to accommodate the electrode assembly, and including an opening portion to expose the electrode assembly; a cap plate coupled with the case to cover an outer peripheral region of the opening portion and including a through-hole to expose a center region of the opening portion; and a terminal plate connected to the second electrode tab to be insulation-bonded to the cap plate, and including a flange part covering the through-hole and a protruding part passing through the through-hole from a center portion of the flange part.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, a separator located between the first electrode and the second electrode, a first electrode tab extended from the first electrode, and a second electrode tab extended from the second electrode; a case connected to the first electrode tab to accommodate the electrode assembly, and including an opening portion to expose the electrode assembly; a cap plate coupled with the case to cover an outer peripheral region of the opening portion and including a through-hole to expose a center region of the opening portion; and a terminal plate connected to the second electrode tab to be insulation-bonded to the cap plate, and including a flange part covering the through-hole and a protruding part passing through the through-hole from a center portion of the flange part.

A battery top cover structure includes a top cover sheet and a first electrode arranged thereon. A sealing sleeve is sleevedly provided between the first electrode and the top cover sheet. The first electrode includes a conductive part and a welding part. A top of the welding part passes through the top cover sheet and is fixed to the conductive part. A bottom of the welding part is fixed to the bottom surface of the top cover sheet by means of a plastic part. An assembly method of the battery top cover structure is also provided.

A battery top cover structure includes a top cover sheet and a first electrode arranged thereon. A sealing sleeve is sleevedly provided between the first electrode and the top cover sheet. The first electrode includes a conductive part and a welding part. A top of the welding part passes through the top cover sheet and is fixed to the conductive part. A bottom of the welding part is fixed to the bottom surface of the top cover sheet by means of a plastic part. An assembly method of the battery top cover structure is also provided.

The present invention relates to a secondary battery having improved output and safety. In one embodiment, disclosed is a secondary battery comprising: an electrode assembly comprising a first electrode, a second electrode and a separator; a case for accommodating the electrode assembly; and a cap assembly coupled to the upper part of the case, wherein the first electrode comprises a first current collector, a first active material layer in which the first active material layer is applied onto the first current collector, a first uncoated area on which a first active material is not applied, and a first electrode tab electrically connected to the first current collector, and the first electrode tab comprises a current collection tab, which is a part of the first current collector, and a lead tab attached to the first current collector.

The present invention relates to a secondary battery having improved output and safety. In one embodiment, disclosed is a secondary battery comprising: an electrode assembly comprising a first electrode, a second electrode and a separator; a case for accommodating the electrode assembly; and a cap assembly coupled to the upper part of the case, wherein the first electrode comprises a first current collector, a first active material layer in which the first active material layer is applied onto the first current collector, a first uncoated area on which a first active material is not applied, and a first electrode tab electrically connected to the first current collector, and the first electrode tab comprises a current collection tab, which is a part of the first current collector, and a lead tab attached to the first current collector.