Abstract: A porous membrane may be manufactured with a high content of filler material and a polymer binder. After forming the membrane, the membrane may be post processed to reform the polymer binder into a stronger yet still porous membrane. The post processing may include bringing the membrane above the melt temperature of the polymer or by immersing the membrane in a solvent. Photomicrographs show that the structure may change, yet the performance of the material in batteries and other electrochemical cells may remain the same or even improve.

Abstract: A microporous membrane may be manufactured using a polymer binder and a filler material using a liquid pore forming agent having a surface free energy that is lower than that of the filler and higher than that of the polymer. The repulsion of the pore forming agent to the polymer may form the pores of the membrane, while the attraction of the polymer to the filler may encapsulate the filler into the structure of the membrane. The filler may be particles that are on the order of or smaller than the wall thickness of the microporous structure.

Abstract: A porous membrane may have a high concentration of spherical fillers with a polymer binder. The polymer binder may have an affinity for the filler materials and may hold the filler materials together in a porous structure with high tortuosity and consistent pore size. The membrane may be manufactured with a reinforcing web, such as non-woven web. The membrane may be greater than 50% porous with a less than 1 micron pore size. Within the pore walls that may be less than 0.02 microns in width, a densely packed filler material may have an average diameter of less than 0.005 microns.

Abstract: A porous membrane may have a high concentration of spherical fillers with a polymer binder. The polymer binder may have an affinity for the filler materials and may hold the filler materials together in a porous structure with high tortuosity and consistent pore size. The membrane may be manufactured with a reinforcing web, such as non-woven web. The membrane may be greater than 50% porous with a less than 1 micron pore size. Within the pore walls that may be less than 0.02 microns in width, a densely packed filler material may have an average diameter of less than 0.005 microns.

Abstract: A porous membrane may be manufactured with a high content of filler material and a polymer binder. After forming the membrane, the membrane may be post processed to reform the polymer binder into a stronger yet still porous membrane. The post processing may include bringing the membrane above the melt temperature of the polymer or by immersing the membrane in a solvent. Photomicrographs show that the structure may change, yet the performance of the material in batteries and other electrochemical cells may remain the same or even improve.

Abstract: A microporous membrane may be manufactured using a polymer binder and a filler material using a liquid pore forming agent having a surface free energy that is lower than that of the filler and higher than that of the polymer. The repulsion of the pore forming agent to the polymer may form the pores of the membrane, while the attraction of the polymer to the filler may encapsulate the filler into the structure of the membrane. The filler may be particles that are on the order of or smaller than the wall thickness of the microporous structure.