Microporous materials including a melt-processable, semi-crystalline, thermoplastic (co)polymer, wherein the thermoplastic (co)polymer is miscible in a compatible liquid when heated above a melting temperature of the semi-crystalline thermoplastic (co)polymer, further wherein the microporous material is comprised of a plurality of filaments substantially aligned in a first longitudinal direction, and a mesh extending laterally between the filaments, the mesh comprising a network of interconnected pores having a median diameter less than one micrometer. Methods of making and using such microporous materials (e.g. as films, membranes, battery separators, capacitor separators, fluid filtration articles, separation articles, and the like) are also described.