Separator filled with electrolyte
AssigneeMedtronic, Inc.
InventorsChristian S. Nielsen, Timothy Bomstad
Life of this patent
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Abstract
Methods are provided to suitably impregnate low surface energy separator materials with polar electrolyte in an electrolytic capacitor. Backfilling methods overcome the high contact angles exhibited by polar electrolytes on porous hydrophobic separators, forcing the electrolyte into the separator pores, thereby sufficiently impregnating the separator disposed between two electrodes within the capacitor assembly. Methods enable use of separators sans surfactant or surface modifications to improve wetting.
Claims18
A method of backfilling a capacitor assembly comprising:
- (a) evacuating the interior of a capacitor assembly, the capacitor assembly comprising at least two electrodes and a micro-porous separator disposed between the electrodes, the capacitor assembly sealed from the exterior atmosphere except via at least one fill-port,
- wherein the micro-porous separator is free of surfactant and not surface modified to increase wettability;
- (b) coupling the fill-port to a reservoir of liquid electrolyte, where the pressure on the liquid electrolyte is greater than the interior pressure of the evacuated capacitor assembly, thereby forcing the liquid electrolyte into the evacuated capacitor assembly through the fill-port.
A method of backfilling a capacitor assembly comprising:
- (a) evacuating the interior atmosphere of a capacitor assembly using vacuum, the capacitor assembly comprising a pair of electrodes and a porous separator disposed between the electrodes, the capacitor assembly sealed from the exterior atmosphere except via at least one fill-port,
- wherein the porous separator is free of surfactant and not surface modified to increase wettability;
- (b) coupling the fill-port to a reservoir of liquid electrolyte;
- (c) applying pressure to the reservoir of liquid electrolyte, thereby forcing the liquid electrolyte into the evacuated capacitor assembly through the fill-port;
- (d) re-evacuating the interior of the capacitor assembly to remove any volume of residual gas;
- and
- (e) replacing the volume of residual gas with liquid electrolyte.
A method of backfilling a capacitor assembly comprising:
- (a) evacuating the interior atmosphere of a capacitor assembly using vacuum, the capacitor assembly comprising:
- at least one pair of electrodes, at least one of the electrodes comprising tantalum;
- and
- a porous separator disposed between the electrodes, the porous separator comprising a hydrophobic polymer and the porous separator is free of surfactant and not surface modified to increase wettability;
- wherein, the capacitor assembly is sealed from the exterior atmosphere except via at least one fill-port;
- (b) coupling the fill-port to a reservoir of liquid, polar electrolyte, the liquid electrolyte comprising water and an acid;
- and
- (c) applying pressure to the reservoir of liquid, polar electrolyte, thereby forcing the liquid, polar electrolyte into the evacuated capacitor assembly through the fill-port;
- and
- (d) sealing the fill-port.
Dependencies are inferred from the claim text.