Methods of the present invention are provided for forming a plurality of electrochemical cell layers, each cell layer generally including a pair of electrodes and a separator electrically insulating the pair of electrodes. Cells of a desired size are formed by slicing the laminar sheet through both opposing major surfaces. In certain embodiments, individual cells are defined by fill regions, filled with removable substances. Thus, when the cells are sliced, individual cells and in certain embodiments current collectors or conductors are exposed with minimal or no further processing. In other embodiments, fluid access channels or porous layers are filled with removable substances. Thus, when the cells are sliced, structural support is provided for the intended void regions.