The disclosed embodiments relate to a battery cell which includes a set of electrode sheets of different dimensions arranged in a stacked configuration to facilitate efficient use of space inside a portable electronic device. For example, the electrode sheets may be arranged in the stacked configuration to accommodate a shape of the portable electronic device. The stacked configuration may be based on a non-rectangular battery design such as a toroidal design, an L-shaped design, a triangular design, a pie-shaped design, a cone-shaped design, and/or a pyramidal design.