Samsung patents battery design with grooves to hold internal parts

1. A secondary battery comprising: a first current collector; a second current collector arranged to face the first current collector; a cell stack, which is provided between the first and second current collectors, the cell stack comprising a plurality of stacked unit cells; first and second fixing members spaced apart from each other, the first and second fixing members being configured to fix the cell stack; a plurality of primary current collectors, provided on side surfaces of the cell stack, wherein at least two of the primary current collectors are connected to the first current collector, and a remainder of the primary current collectors are connected to the second current collector; and a case accommodating the first and second current collectors, the cell stack, the first and second fixing members, and the plurality of primary current collectors, wherein the cell stack comprises a plurality of nonparallel linear side surfaces, at least one of the plurality of primary current collectors is on each of the linear side surfaces, the first and second current collectors are on the cell stack between the first and second fixing members, and each of the first and second current collectors comprises a groove configured to accommodate portions of the first and second fixing members, the cell stack comprises: a first side surface that is linear; a second side surface that is linear and nonparallel with the first side surface; a third side surface that is linear and nonparallel with the first and second side surfaces; and a fourth side surface that is linear and nonparallel with the first side surface, second side surface, and third side surface, one primary current collector is provided on each of the first side surface, second side surface, third side surface, and fourth side surface, and a portion of a current collector layer of a first electrode layer of each of the plurality of unit cells is connected to the primary current collector provided on the first side surface, and a remaining portion of the current collector layer of the first electrode layer to which the portion of the current collector layer of the first electrode layer is not connected is connected to the primary current collector provided on the second side surface.