BATTERY CELLS WITH SEPARATORS INCLUDING JOINED ENDS

A battery cell includes C cathode electrodes each including a cathode active material arranged on a cathode current collector, A anode electrodes each including an anode active material arranged on an anode current collector, and S separators. C, A, and S are integers greater than one. The S separators include first ends and second ends. The first ends and the second ends of the S separators extend from opposite sides of the C cathode electrodes and the A anode electrodes. The first ends and the second ends of the S separators are connected together using hot pressing, a hot knife, a polymer bath, or ultrasonic welding.