Ultracapacitor and method of manufacturing the same

1. An ultracapacitor comprising:

a negative porous electrode in contact with a negative conducting plate;

a positive porous electrode in contact with a positive conducting plate

an ultracapacitor separator separating said negative porous electrode from said positive porous electrode; and

an electrolytic solution impregnating said positive and negative porous electrodes and said ultracapacitor separator;

where said ultracapacitor separator having a change in thickness of less than 8% when heated to a temperature of at least 200° C.; and

said ultracapacitor separator including a microporous material comprising:

an ultrahigh molecular weight polyethylene (UHMWPE) and a particulate filler distributed throughout said microporous material;

where said filler constitutes from about 5 percent to 95 percent by weight of said microporous material;

where said microporous material has a network of interconnecting pores communicating throughout said microporous material, said pores constituting at least 25 percent by volume of said microporous material, where said pores create a pore distribution;

where said microporous material has no pores greater in size than 1.0 micrometers; and

where change in volume divided by log d for the pores of said microporous material is less than 2 cc/g for the entire pore distribution.

2. The ultracapacitor of claim 1 where said ultracapacitor separator having a surface resistance of less than 30 ohms/cm 2 at any temperature less than 200° C.

3. The ultracapacitor of claim 1 , where said microporous material has a machine direction (MD) tensile strength of greater than 25 N/mm 2 .

4. The ultracapacitor of claim 1 , where said filler is selected from the group consisting essentially of: silica, precipitated silica, silica gel, fumed silica, mica, montmorillonite, kaolinite, asbestos, talc, diatomaceous earth, vermiculite, natural and synthetic zeolites, cement, calcium silicate, clay, aluminum silicate, sodium aluminum silicate, aluminum polysilicate, alumina silica gels, glass particles, carbon black, activated carbon, carbon fibers, charcoal, graphite, titanium dioxide, lead oxide, tungsten, iron oxide, copper oxide, zinc oxide, antimony oxide, zirconia, magnesia, alumina, molybdenum disulfide, zinc sulfide, barium sulfate, strontium sulfate, calcium carbonate, and magnesium carbonate.

5. The ultracapacitor of claim 1 where said UHMWPE is mixed with a high density (HD) polyethylene to produce a polyolefin mixture;

where said polyolefin mixture has at least 50% UHMWPE by weight of said polyolefin mixture; and

where said filler to said polyolefin mixture is in a range of from 1:9 to 15:1 filler to polyolefin mixture by weight and where said matrix comprises UHMWPE and HD polyethylene and said particulate filler distributed throughout said matrix.

6. The ultracapacitor of claim 1 where said microporous material being made from a precursor material where said microporous material has a reduction of thickness of 5% or more from said precursor material.

7. An ultracapacitor separator comprising:

a microporous material having a change in thickness of less than 8% when heated to a temperature of at least 200° C.

wherein said microporous material being utilized in an ultracapacitor as an ultracapacitor separator separating a negative porous electrode from a positive porous electrode;

said ultracapacitor separator including a microporous material comprising:

an ultrahigh molecular weight polyethylene (UHMWPE) and a particulate filler distributed throughout said microporous material;

where said filler constitutes from about 5 percent to 95 percent by weight of said microporous material;

where said microporous material has a network of interconnecting pores communicating throughout said microporous material, said pores constituting at least 25 percent by volume of said microporous material, where said pores create a pore distribution;

where said microporous material has no pores greater in size than 1.0 micrometers; and

where change in volume divided by log d for the pores of said microporous material is less than 2 cc/g for the entire pore distribution.

8. The ultracapacitor separator of claim 7 where said ultracapacitor separator having a surface resistance of less than 30 ohms/cm 2 at any temperature less than 200° C.

9. The ultracapacitor separator of claim 7 where said

microporous material has no pores greater in size than 0.50 micrometers; and

where said median pore size is between or equal to 0.01 and 0.3 micrometers and the pores vary in size by plus or minus 0.2 micrometers or less.

10. The ultracapacitor separator of claim 9 , having a machine direction (MD) tensile strength of greater than 25 N/mm 2 .

11. The ultracapacitor separator of claim 9 where said microporous material being made from a precursor material where said microporous material has a reduction of thickness of 5% or more from said precursor material.

12. An ultracapacitor made according to a method for producing an ultracapacitor comprising the steps of:

providing a negative porous electrode in contact with a negative conducting plate;

providing a positive porous electrode in contact with a positive conducting plate;

providing an ultracapacitor separator having a change in thickness of less than 8% at a curing temperature of at least 200° C., where said ultracapacitor separator separating said negative porous electrode from said positive porous electrode;

said ultracapacitor separator including a microporous material comprising:

an ultrahigh molecular weight polyethylene (UHMWPE) and a particulate filler distributed throughout said microporous material;

where said filler constitutes from about 5 percent to 95 percent by weight of said microporous material;

where said microporous material has a network of interconnecting pores communicating throughout said microporous material, said pores constituting at least 25 percent by volume of said microporous material, these pores create a pore distribution;

where said microporous material has no pores greater in size than 1.0 micrometers; and

where change in volume divided by log d for the pores of this microporous material is less than 2 cc/g for the entire pore distribution;

providing an electrolytic solution;

said electrolytic solution impregnating said negative porous electrode, said positive porous electrode, and said ultracapacitor separator; and

curing said ultracapacitor of at least 200° C.