TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Composition: The ceramic particles are chosen from inorganic oxide particles and inorganic nitride particles. The ceramic particles comprise alumina, boehmite, aluminum nitride, boron nitride, tin nitride, zinc oxide, zirconia and silica, preferably 65-95% boehmite, and remainder of boron nitride or aluminum nitride. The inorganic ceramic material comprises boehmite, boron nitride, and aluminum nitride.    TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Properties: The electrochemical cell has average pore size of 25-35 nm, and porosity of 40-45%.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The single inorganic particulate in the comparative composite ceramic separator is primary inorganic particulate material or secondary inorganic particulate material of the flexible composite ceramic separator.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The polymeric binder comprises a polymer chosen from polyvinylidene difluoride and its copolymer, polyvinyl ether, urethane, acrylic, cellulosic, styrene-butadiene copolymer, natural rubber, chitosan, nitrile rubber, silicone elastomer, polyethylene oxide or its copolymer, and/or polyphosphazene. The content of pores having pore size of 10-90 nm in the porous separator is less than 1%. The content of pores having diameter of more than 100 nm in the porous separator is less than 1% or 0.1%. Preferred Properties: The porous separator exhibits less than 1% shrinkage when exposed at 200 degrees C for 1 hour or more. The porous separator has average pore size of 10-90 nm, and porosity of 35-50%, preferably 40-45%. The porous composite separator has average pore size of 20-40 nm and porosity of 40-45%. Each pores of porous separator has diameter of 10-50 nm. The porous separator has a pore volume. 90% or more (excluding 90%) pore volume of porous separator comprises pores having pore diameter of less than 100 nm. The thermal conductivity of the porous separator increases when temperature is increased from 25-50 degrees C and tested based on ASTM E1461 and/or ASTM 1530.