The present invention relates to an energy storage unit (1) having a plurality of electrochemical cells (2), wherein the electrochemical cells (2) each have a first outer face (3) comprising a first electrode (5), and a second outer face (4) comprising a second electrode (6), and the electrochemical cells (2) are electrically interconnected owing to the lined-up arrangement (9) of the electrochemical cells (2) by way of the outer faces (3, 4) by means of the electrodes (5, 6). The energy storage unit (1) additionally comprises a first frame element (7) and a second frame element (8), which frame elements are directly or indirectly connected to one another, wherein the first frame element (7) is arranged at one end (10) of the lined-up arrangement (9) of the electrochemical cells (2), and the second frame element (8) is arranged at the other end (11) of the lined-up arrangement (9) of the electrochemical cells (2). The present invention also relates to a battery cell (2) for use with an energy storage unit (1) according to the invention, and also to a method for producing a battery cell (2) of this kind.