The invention provides a modular series battery based on special-shaped winding cores and a preparation method thereof, and relates to the technical field of batteries, the modular series battery comprises at least two first-type winding battery cores, and each first-type winding battery core is provided with an electric connection end face; the at least one second-type winding
battery cell is provided with two electric connection end surfaces, and the second-type winding
battery cell is connected in series between the first-type winding
battery cell and the second-type winding battery
cell, starting from the first-type winding battery
cell and ending from the first-type winding battery
cell; every two adjacent winding battery cells are in
butt joint through the corresponding electric connection end faces, and a bridging conductive piece is arranged between every two butt-joint electric connection end faces and used for being selectively connected with
electrode current collectors of the same polarity. And the
electrode leading-out ends of the first type of winding battery cells and the second type of winding battery cells and the leading-out parts of the bridging conductive pieces are connected to the total positive
electrode end and the total negative electrode end in parallel according to electrode polarities. The problems that an existing
lithium battery is large in high-rate
internal resistance, the multi-tab process is complex, the thin battery cell stacking integration efficiency is low, and the reliability is poor can be solved.