Abstract: An electrochemical cell assembly (500) includes a first cell and a second cell. The first cell can include a first anode (503) and a first cathode (504), wound in a first jellyroll assembly (501) with a first jellyroll assembly exterior defined by the first cathode. The second cell can include a second anode (512) and a second cathode (513), wound in a second jellyroll assembly (502) with a second jellyroll assembly exterior defined by the second anode. The first cell and the second cell can be arranged in a housing with the first jellyroll assembly exterior adjacent to the second jellyroll assembly exterior to improve energy density. The first cell assembly and the second cell assembly can have different widths to create differently shaped cell assemblies.

Abstract: An electrochemical cell assembly (500) includes a first cell and a second cell. The first cell can include a first anode (503) and a first cathode (504), wound in a first jellyroll assembly (501) with a first jellyroll assembly exterior defined by the first cathode. The second cell can include a second anode (512) and a second cathode (513), wound in a second jellyroll assembly (502) with a second jellyroll assembly exterior defined by the second anode. The first cell and the second cell can be arranged in a housing with the first jellyroll assembly exterior adjacent to the second jellyroll assembly exterior to improve energy density. The first cell assembly and the second cell assembly can have different widths to create differently shaped cell assemblies.

Abstract: A polymer electrolyte membrane fuel cell stack (52) includes a plurality of membrane electrode assemblies (12) having evenly distributed fuel concentration across an anode (24), and efficient cooling across a cathode (26). A first plate (14) has a fuel side (28) with a plurality of serpentine channels (40) formed therein for distributing fuel across the anode (24), and a second plate (16) has an oxidant side (30) with oxidant channels (42) formed therein for distributing an oxidant across the cathode (26). The membrane electrode assembly (12) has an even fuel concentration thereacross, and the oxidant is routed through the cell (10) at least twice for absorbing heat prior to being distributed across the cathode (26).