Abstract: A spacer mesh is provided and is configured to separate a first ion conducting membrane from a second ion conducting membrane to define a space between the membranes, comprising a plurality of strands consisting essentially of a polymer having a heat distortion temperature of at least 90° C. at 66 psi, and a melt flow index within the range of 3 g/10 min to 6 g/10 min, and being chemically stable at pH>13 or pH<2. The spacer mesh includes a first plurality of spaced apart substantially parallel strand elements, and a second plurality of spaced apart substantially parallel strand elements, wherein the first plurality of strand elements and the second plurality of strand elements are connected to define a netting having a plurality of apertures, each of the apertures having a plurality of vertices defined by a pair of intersecting strands, and a distance between non-adjacent vertices in an aperture is less than 10/1000 of an inch.