Discussed is a coupling structure including a first member and a second member which are adjacent to each other, the first member and second member are weld-coupled to each other, a welding part of the first member and the second member includes a first welding part formed in the first member and a second welding part formed in the second member with respect to a coupling surface of the first member and the second member, and the first welding part and the second welding part have a mutually asymmetrical shape.

Disclosed are a secondary battery, a battery module and an electric vehicle. The secondary battery includes an electrode assembly, a housing and a top cover assembly. The housing has an accommodating chamber, the accommodating chamber having an opening, and the electrode assembly being accommodated in the accommodating chamber. The electrode assembly includes a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber. The top cover assembly includes a top cover plate, a first electrode terminal and a second electrode terminal, the top cover plate being connected to the housing and located on a side of the electrode assembly in the axial direction, and the first electrode terminal and the second electrode terminal both protruding from the top cover plate and being electrically connected to the electrode assembly.

Disclosed are a secondary battery, a battery module and an electric vehicle. The secondary battery includes an electrode assembly, a housing and a top cover assembly. The housing has an accommodating chamber, the accommodating chamber having an opening, and the electrode assembly being accommodated in the accommodating chamber. The electrode assembly includes a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber. The top cover assembly includes a top cover plate, a first electrode terminal and a second electrode terminal, the top cover plate being connected to the housing and located on a side of the electrode assembly in the axial direction, and the first electrode terminal and the second electrode terminal both protruding from the top cover plate and being electrically connected to the electrode assembly.

A battery module includes a plurality of battery cells disposed in at least two rows. The battery cells in adjacent rows are offset from each other. Each of the plurality of battery cells includes a cover and a first terminal that extends from the cover outward. The first terminal is configured to be coupled to a second terminal on an adjacent battery cell. The plurality of battery cells are electrically coupled to each other in a zigzag pattern via the first and second terminals.

A battery module having a plurality of battery cells and a first housing element (21) and a second housing element (22) is disclosed. The housing elements together form an interior space (9) in which the plurality of battery cells is accommodated, and are each formed from a metal material, the first housing element (21) having a projection (31) and the second housing element (22) having an indentation (32), the projection (31) engaging in the indentation (32). On a side facing away from the interior space, the first housing element (21) has a first weld region (41) and the second housing element (22) has a second weld region (42), the first weld region (41) and the second weld region (42) being connected to one another by welding.

Discussed is an underbody for a vehicle including a tray member fastened to a lower portion of a vehicle body frame and including a receiving portion having a structure with an open lower surface to accommodate a battery module; and a cover member to cover the open lower surface of the receiving portion, wherein the cover member includes a flow path to circulate a refrigerant fluid.

Discussed is an underbody for a vehicle including a tray member fastened to a lower portion of a vehicle body frame and including a receiving portion having a structure with an open lower surface to accommodate a battery module; and a cover member to cover the open lower surface of the receiving portion, wherein the cover member includes a flow path to circulate a refrigerant fluid.

A power storage device includes a case body made of metal and having an opening that opens in at least one direction, a power storage module placed inside the case body, a closing plate made of metal and welded to the case body so as to close the opening of the case body, an insulating sheet covering an inner surface of the case body and an inner surface of the closing plate, and a covering portion made of an insulating material and covering a boundary portion between the inner surface of the case body and the inner surface of the closing plate.

A power storage device includes a case body made of metal and having an opening that opens in at least one direction, a power storage module placed inside the case body, a closing plate made of metal and welded to the case body so as to close the opening of the case body, an insulating sheet covering an inner surface of the case body and an inner surface of the closing plate, and a covering portion made of an insulating material and covering a boundary portion between the inner surface of the case body and the inner surface of the closing plate.

A battery cassette is disclosed. The battery cassette may include a frame including one or more hollow tubes. The battery cassette may further include a seal component having one or more hollow tubes aligned with the hollow tubes of the frame. The frame and the seal component may be configured to receive one or more battery cells in the hollow tubes.