Abstract: In the method for manufacturing the battery module according to this invention, after a pair of welding upper/lower electrodes 21, 22 or 23, 24 are arranged in contact on the cases 16, 16 of adjacent unit cells 10a, 10b of a plurality of unit cells aligned in a line, a welding current is passed between the pair of welding upper electrodes 21, 23 from a welding power source while both ends of the unit cells 10a, 10b, 10c are pressurized by pressurizing members 31, 32 under a prescribed pressure. Thus, Joule heat is generated at the contact portion between the bottom of the outer case 16 of the unit cell 10a and the positive polarity terminal 18 of the unit cell 10b so that the contact portion melts. Accordingly, the bottom of the outer case 16 of the unit cell 10a and the positive polarity terminal 18 of the unit cell 10b are welded to each other at the contact portion.

Abstract: A battery module of the present invention comprises an annular connecting member 10 having an aperture 14 at a position corresponding to a cap 8 provided on a sealing plate 7 and between the sealing member 7 of one cell B and a bottom of a can 6 of the other cell A. The annular connecting member 10 comprises an annular base portion 11 having its outer diameter smaller than an inner diameter of the opening portion of the can 6, a convex portion 12 with bottom protruding upward or downward alternately from the annular base portion 11, and a projection 13 projecting from the bottom of the convex portion 12. Thereby, the connecting portion between the cell A and the cell B has a collecting path of a length between both projections 13, namely, a length between the sealing plate 7 of the cell B and the bottom of the can 6 of the cell A, whereby the voltage drop across the connecting portion decreases, resulting in a battery module having high operation voltage.

Abstract: A battery module of the present invention comprises an annular connecting member 10 having an aperture 14 at a position corresponding to a cap 8 provided on a sealing plate 7 and between the sealing member 7 of one cell B and a bottom of a can 6 of the other cell A. The annular connecting member 10 comprises an annular base portion 11 having its outer diameter smaller than an inner diameter of the opening portion of the can 6, a convex portion 12 with bottom protruding upward or downward alternately from the annular base portion 11, and a projection 13 projecting from the bottom of the convex portion 12. Thereby, the connecting portion between the cell A and the cell B has a collecting path of a length between both projections 13, namely, a length between the sealing plate 7 of the cell B and the bottom of the can 6 of the cell A, whereby the voltage drop across the connecting portion decreases, resulting in a battery module having high operation voltage.

Abstract: In the method for manufacturing the battery module according to this invention, after a pair of welding upper/lower electrodes 21, 22 or 23, 24 are arranged in contact on the cases 16, 16 of adjacent unit cells 10a, 10b of a plurality of unit cells aligned in a line, a welding current is passed between the pair of welding upper electrodes 21, 23 from a welding power source while both ends of the unit cells 10a, 10b, 10c are pressurized by pressurizing members 31, 32 under a prescribed pressure. Thus, Joule heat is generated at the contact portion between the bottom of the outer case 16 of the unit cell 10a and the positive polarity terminal 18 of the unit cell 10b so that the contact portion melts. Accordingly, the bottom of the outer case 16 of the unit cell 10a and the positive polarity terminal 18 of the unit cell 10b are welded to each other at the contact portion.