SECONDARY BATTERY AND MANUFACTURING METHOD THEREOF, BATTERY MODULE, AND APPARATUS

The present application relates to a secondary battery and manufacturing method thereof, a battery module and an apparatus. The secondary battery includes an electrode assembly including a main body portion and a tab extending out from the main body portion; a current collecting member including a guiding section, which extends in a direction perpendicular to a length direction of the electrode assembly; a transition connecting piece, being separately provided from the current collecting member and including a current collecting portion and a fixing portion, the current collecting portion being adapted to connect with the tab to form a first connection region, the fixing portion being adapted to connect with the guiding section to form a second connection region, and respective projections of the first connection region and the second connection region on a plane perpendicular to the length direction do not overlap.