The porosity of a battery separator determines how easily ions can move back and forth between the battery's anode and cathode. Higher battery separator porosity means freer ion flow with less internal resistance.
In traditional battery separators with only 35% to 50% porosity, ion flow within the cell is often restricted. As a result, at high discharge rates, only a small fraction of the cell's energy may be available to power external circuits. The rest is trapped in the cell or lost to heat.
SYMMETRIX® microporous lithium-ion battery separators use a patent-pending process that yields 80% porosity in a thin, flexible film. This high porosity membrane reduces resistance within the battery, allowing for faster cell charge and discharge (with no degradation of battery performance), better thermal control, less waste heat and longer battery cycle life.
Lithium-ion batteries manufactured with SYMMETRIX ceramic-filled, microporous battery separators yield up to four times more energy at high discharge rates than batteries using traditional polyolefin battery separators.