One embodiment of the present subject matter includes a stack of substantially planar electrodes, the stack in alignment and having a stack form factor. Embodiments include a first housing portion including a first beveled edge at least partially defining a first stack aperture adapted to at least partially receive the stack, the first stack opening having a first thickness proximal the beveled edge, and a second thickness away from the first beveled edge and a second housing portion including a second edge defining a second stack aperture adapted to at least partially receive the stack. Embodiments are included wherein the second housing portion is joined to the first housing portion such that the first housing portion and the second housing portion define an interior space which substantially conforms to the stack form factor.