Non-aqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery includes: an electrode assembly; a rectangular outer casing; a sealing plate; an electrode terminal on the sealing plate; a first current collector connected to the electrode terminal; a second current collector connected to the first current collector; and a tab group connected to the second current collector. The second current collector is a flat plate, and includes a fuse portion having a slit extending in a lateral direction of the flat plate. The tab group is connected to the second current collector at a position closer to one side in the lateral direction, and is bent at a connection portion with the second current collector such that the bent tab group extends parallel to the side wall. The fuse portion includes a portion with a large sectional area on the other side of the slit in the lateral direction.