A foldable frame for a battery cell assembly includes a one-piece main body. The main body has a first section, a second section, and a third section. The first section is coupled to each of a second section and a third section with living hinges. The first section is configured to receive a first battery cell. The second section is configured to receive an expansion unit and a second battery cell. The second section folds over the first battery cell. The third section is configured to fold over the second battery cell, thereby securing each of the first battery cell, the expansion unit, and the second battery cell within the foldable frame.