A battery module for an electric vehicle, comprising: - a plurality of secondary battery cells, at least one positive current collector structure, and at least one negative current collector structure (29a, 29b); wherein - each of the secondary battery cells comprises an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, a positive terminal electrically connected to the positive electrode, a negative terminal electrically connected to the negative electrode, and a case receiving the electrode assembly; wherein - the at least one positive current collector structure is arranged to interconnect the positive terminals of at least two of the plurality of secondary battery cells with each other, and the at least one negative current collector structure (29a, 29b) is arranged to interconnect the negative terminals of at least two of the plurality of secondary battery cells with each other; wherein - the case of each of the plurality of secondary battery cells comprises a groove, wherein the groove is arranged along a circumference of said case and the groove comprises at least a part of the negative terminal of said secondary battery cell; and wherein - the at least one negative current collector structure (29a, 29b) comprises at least one flat negative busbar (42a, 42b) arranged in a plane that is aligned with the circumference of the case of each of at least two of the plurality of secondary battery cells, wherein the at least one flat negative busbar (42a, 42b) projects into the groove of the case of each of said at least two secondary battery cells to connect the negative current collector structure (29a, 29b) and the negative terminals of said at least two secondary battery cells with each other, characterized in that the at least one flat negative busbar (42a, 42b) and the groove of the case of each of said at least two secondary battery cells are aligned in the same plane. - a plurality of secondary battery cells, at least one positive current collector structure, and at least one negative current collector structure (29a, 29b); wherein - each of the secondary battery cells comprises an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, a positive terminal electrically connected to the positive electrode, a negative terminal electrically connected to the negative electrode, and a case receiving the electrode assembly; wherein - the at least one positive current collector structure is arranged to interconnect the positive terminals of at least two of the plurality of secondary battery cells with each other, and the at least one negative current collector structure (29a, 29b) is arranged to interconnect the negative terminals of at least two of the plurality of secondary battery cells with each other; wherein - the case of each of the plurality of secondary battery cells comprises a groove, wherein the groove is arranged along a circumference of said case and the groove comprises at least a part of the negative terminal of said secondary battery cell; and wherein - the at least one negative current collector structure (29a, 29b) comprises at least one flat negative busbar (42a, 42b) arranged in a plane that is aligned with the circumference of the case of each of at least two of the plurality of secondary battery cells, wherein the at least one flat negative busbar (42a, 42b) projects into the groove of the case of each of said at least two secondary battery cells to connect the negative current collector structure (29a, 29b) and the negative terminals of said at least two secondary battery cells with each other, characterized in that the at least one flat negative busbar (42a, 42b) and the groove of the case of each of said at least two secondary battery cells are aligned in the same plane.