A primary lithium electrochemical cell housed in a casing having a curved side wall intermediate opposed generally planar face walls is described. The cell comprises an anode and a cathode that each has a plurality of face portions joined together by connecting portions. The opposite polarity face portions and connecting portions are aligned with each other and then the electrodes are wound to provide an electrode assembly that fits in the casing. Regardless whether the cell is balanced as either an anode-limited or cathode-limited configuration, however, it is desirable to have the active material of one electrode face portion directly facing the electrode material of the counter electrode face portion. This means that the dimensional extent of the facing electrodes should be as close to each other in areas as possible to match the desired anode- or cathode-limited balance. The same is true for the connecting portions. The cell is of a high energy density for an implantable biomedical device.