High temperature energy storage device

Abstract

To provide a method and an apparatus for improving the performance of electric double layer capacitors at high temperature.SOLUTION: An ultracapacitor includes an energy storage cell immersed in an electrolyte and disposed within a hermetically sealed housing, the electrode includes carbon nanotubes, a total halide content in the electrolyte is refined to less than 200 ppm, the housing has, therein, a barrier including a perfluoroalkoxy (PFA)-based material, and performance with suppressed degradation is exhibited even after charge / discharge testing in a 210°C environment.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The invention disclosed herein relates to a technique for providing an energy storage cell, in particular an electric double layer capacitor capable of operating at high temperatures. [Background technology]

[0002] Energy storage cells are ubiquitous in our society. Many people recognize energy storage cells simply as "batteries," but other types of cells may be included. For example, ultracapacitors have attracted much interest in recent years due to their advantages. In short, many types of energy storage cells are known and used today.

[0003] Generally, energy storage cells include an energy storage medium disposed within a housing (such as a can). Although a metal can may provide robust physical protection for the cell, such a can is typically both electrically and thermally conductive and may react with the energy storage cell. Typically, such reactions increase in rate as the ambient temperature increases. The electrochemical or other properties of many cans may cause a decrease in initial performance and may result in premature degradation of the energy storage cell, especially at high (or elevated) temperatures.

[0004] In practice, various factors contribute to the degradation of the performance of energy storage systems at high (or elevated) temperatures. Thus, there is a need for methods and apparatus that improve the performance of electric super-layer capacitors at high temperatures. Preferably, the methods and apparatus provide the improved performance at minimal cost. Summary of the Invention

[0005] In one embodiment, an ultracapacitor is disclosed that includes an energy storage cell immersed in an electrolyte and disposed within a sealed housing, the cell being electrically coupled to a positive contact and a negative contact, the ultracapacitor configured to output electrical energy at a temperature within a temperature range of approximately 80° C. to 210° C.

[0006] In another embodiment, a method of manufacturing an ultracapacitor is presented, the method including disposing an energy storage cell including an energy storage medium in a housing; and configuring the ultracapacitor to operate within a temperature range of about 80° C. to about 210° C.

[0007] In yet another embodiment, a method of making an ultracapacitor is presented, the method including disposing an energy storage cell including an energy storage medium in a housing; and filling the housing with an electrolyte adapted to operate within a temperature range of about 80° C. to about 210° C.

[0008] In another embodiment, an ultracapacitor is disclosed that includes an energy storage cell wetted with an electrolyte and disposed within a housing, the moisture level within the housing being about 1000 ppm or less based on the combined weight of the storage cell and the electrolyte.

[0009] In yet another embodiment, an ultracapacitor is disclosed that includes an energy storage cell wetted with an electrolyte and disposed within a housing, the housing having a level of halide impurities of 1000 ppm or less based on the combined weight of the storage cell and the electrolyte.

[0010] In another embodiment, a method for characterizing contaminants in an ultracapacitor is presented, the method including destroying a housing of the ultracapacitor to access the contents of the housing, sampling the contents, and analyzing the sample.

[0011] In one embodiment, an ultracapacitor is disclosed that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 100° C. to about 150° C.

[0012] In one embodiment, an ultracapacitor is disclosed that exhibits a volumetric leakage current of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 140° C. to 180° C.

[0013] In one embodiment, an ultracapacitor is disclosed that exhibits a volumetric leakage current of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 170° C. to 210° C.

[0014] In another embodiment, a method of providing a high temperature rechargeable energy storage device is disclosed. The method includes selecting a high temperature rechargeable energy storage device (HTRESD) that exhibits an initial peak power density of 0.01 W / L to 100 kW / L and a life span of at least 20 hours when exposed to an ambient temperature in a temperature range of about 80° C. to about 210° C.; and providing the storage device.

[0015] In another embodiment, a method of using a high temperature rechargeable energy storage device is disclosed. The method includes obtaining an HTRESD; and at least one of cycling the HTRESD by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and holding a voltage across the HTRESD for 20 hours, such that the HTRESD exhibits a peak power density of 0.005 W / L to 75 kW / L after 20 hours when operating at an ambient temperature within a temperature range of about 80° C. to about 210° C.

[0016] In another embodiment, a method of using a high temperature rechargeable energy storage device is disclosed. The method includes obtaining an ultracapacitor; and maintaining a voltage across the ultracapacitor such that the ultracapacitor exhibits a peak power density of about 0.005 W / L to about 75 kW / L after 20 hours, wherein the ultracapacitor is exposed to an ambient temperature within a temperature range of about 80° C. to about 210° C. during the voltage maintenance.

[0017] In another embodiment, a method of using an ultracapacitor is disclosed. The method includes obtaining an ultracapacitor including an electrolyte and two electrodes, each of the electrodes being in electrical communication with a current collector and separated from the other electrode by a separator, and one of charging and discharging the ultracapacitor at a current of about 0.1 Wh-kW / L. 2 ~About 100Wh-kW / L 2 in the range of about 80° C. to about 210° C., which combination is mathematically the product of the peak power density and energy density of the ultracapacitor, the ultracapacitor exhibits an endurance time of at least 20 hours when exposed to an ambient temperature in the temperature range of about 80° C. to about 210° C., the endurance being indicated by a decrease in peak power density of about 50% or less over that time, and the ultracapacitor is configured to be charged and discharged at least two times.

[0018] The above and other features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 illustrates one exemplary ultracapacitor embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating a number of carbon nanotubes (CNTs) grown on a substrate. [Diagram 3] FIG. 3 is a block diagram illustrating the deposition of a current collector onto the CNTs of FIG. 3 to provide an electrode component. [Figure 4] FIG. 4 is a block diagram illustrating the addition of a transfer tape to the electrode components of FIG. [Diagram 5] FIG. 5 is a block diagram representing the electrode components during the transfer process. [Figure 6] FIG. 6 is a block diagram illustrating the electrode components after movement. [Figure 7] FIG. 7 is a block diagram illustrating an exemplary electrode made up of multiple electrode components. [Figure 8] FIG. 8 depicts an embodiment of the primary structure of a cation that may be included in an exemplary ultracapacitor. [Figure 9] 9 and 10 present comparative data for exemplary ultracapacitors using crude and purified electrolytes, respectively. [Figure 10] 9 and 10 present comparative data for exemplary ultracapacitors using crude and purified electrolytes, respectively. [Figure 11] FIG. 11 illustrates one embodiment of an exemplary ultracapacitor housing. [Figure 12] FIG. 12 illustrates one embodiment of a storage cell of an exemplary capacitor. [Figure 13] FIG. 13 depicts a barrier disposed within the body (or main body) of the housing. [Figure 14] 14A and 14B (collectively referred to herein as FIG. 14) depict an embodiment of the cap of the housing. [Figure 15] FIG. 15 illustrates the assembly of an ultracapacitor in accordance with the teachings herein. [Figure 16] 16A and 16B (collectively referred to herein as FIG. 16) are graphs depicting ultracapacitor performance for an embodiment without a barrier and a similar embodiment including a barrier, respectively. [Figure 17] FIG. 17 depicts a barrier disposed around a storage cell as a wrapper. [Figure 18] Figures 18A, 18B and 18C (collectively referred to herein as Figure 18) depict an embodiment of a cap comprising multiple layers of material. [Figure 19] FIG. 19 is a cross-sectional view of an electrode assembly including a glass-to-metal seal. [Figure 20] FIG. 20 is a cross-sectional view of the electrode component of FIG. 19 mounted in the cap of FIG. 18B. [Figure 21] FIG. 21 shows the arrangement of the energy storage cells in the assembly. [Figure 22] 22A, 22B, and 22C (collectively referred to herein as FIG. 22) depict an embodiment of an assembled energy storage cell. [Diagram 23] FIG. 23 illustrates the incorporation of polymer insulation into an ultracapacitor. [Figure 24] 24A, 24B and 24C (collectively referred to herein as FIG. 24) depict an embodiment of a mold (or die or template) for another embodiment of an energy storage cap. [Diagram 25] FIG. 25 is a perspective view of an electrode component including a hemispherical piece of material. [Figure 26] 26 is a perspective view of a cap including the electrode components of FIG. 25 attached to the template of FIG. 24. FIG. [Figure 27] FIG. 27 is a cross-sectional view of the cap of FIG. [Figure 28] FIG. 28 shows the connection of the electrode components to the terminals of the storage cell. [Figure 29] FIG. 29 is a transparent isometric view of an energy storage cell disposed in a cylindrical housing. [Diagram 30] FIG. 30 is a side view of a storage cell showing the various layers of one embodiment. [Diagram 31] FIG. 31 is an isometric view of a rolled storage cell including fiducial marks for locating multiple leads. [Diagram 32] FIG. 32 is an isometric view of the storage cell of FIG. 31 when unrolled. [Diagram 33] FIG. 33 depicts a wound storage cell containing multiple leads. [Diagram 34] FIG. 34 illustrates a Z-fold applied to an array of leads (i.e., terminals) connected to a storage cell. [Diagram 35] FIG. 35 is a graph depicting the performance of an exemplary ultracapacitor. [Diagram 36] FIG. 36 is a graph depicting the performance of an exemplary ultracapacitor. [Figure 37]FIG. 37 is a graph depicting the performance of an exemplary ultracapacitor. [Figure 38] FIG. 38 is a graph depicting the performance of an exemplary ultracapacitor. [Figure 39] FIG. 39 is a graph depicting the performance of an exemplary ultracapacitor at 210° C. [Diagram 40] FIG. 40 is a graph depicting the performance of an exemplary ultracapacitor at 210° C. [Diagram 41] FIG. 41 is a graph depicting the performance of an exemplary ultracapacitor at 210° C. [Diagram 42] FIG. 42 is a graph depicting the performance of an exemplary ultracapacitor at 210° C. [Diagram 43] FIG. 43 is a graph depicting the performance of an exemplary ultracapacitor at 210° C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Disclosed herein are capacitors that provide users with improved performance over a wide range of temperatures. For example, the capacitors may be operable at temperatures ranging from as low as about -40°C to as high as about 210°C. In some embodiments, the capacitors are operable at temperatures ranging from as high as about 80°C to as high as about 210°C.

[0021] In general, a capacitor includes an energy storage medium adapted to provide high power density and high energy density when compared to prior art devices. The capacitor includes components configured to ensure operation over a temperature range, and includes any one or more of various forms of electrolyte that are also rated for the temperature range. The combination of structure, energy storage medium, and electrolyte provides the ability to provide robust operation under extreme conditions. To provide some perspective, aspects of one exemplary embodiment are introduced here.

[0022] As shown in FIG. 1, one exemplary embodiment of a capacitor is shown. In this case, the capacitor is an "ultracapacitor 10". The exemplary ultracapacitor 10 is an electric double layer capacitor (EDLC). An EDLC includes at least one pair of electrodes 3 (the electrodes 3 may simply be referred to as a negative electrode 3 and a positive electrode 3 for purposes of reference herein). When assembled into an ultracapacitor 10, each of the electrodes 3 exhibits a double layer of charge at the electrolyte interface. In some embodiments, multiple electrodes 3 are included (e.g., in some embodiments, at least two pairs of electrodes 3 are included). However, for purposes of discussion, only one pair of electrodes 3 is shown. Conventionally, in this specification, at least one of the electrodes 3 uses a carbon-based energy storage medium 1 (discussed further herein) to provide energy storage. However, for purposes of discussion, it is generally assumed that each of the electrodes includes a carbon-based energy storage medium 1. It should be noted that electrolytic capacitors are different from ultracapacitors because the areas of the metal electrodes are significantly different (at least by an order of magnitude).

[0023] Each of the electrodes 3 includes a respective current collector 2 (also referred to as a "charge collector"). In some embodiments, the electrodes 3 are separated by a separator 5. Generally, the separator 5 is a thin structural material (usually a sheet) used to separate the negative electrode 3 from the positive electrode 3. The separator 5 may serve to separate the pair of electrodes 3. When assembled, the electrodes 3 and the separator 5 provide a storage cell 12. Note that in some embodiments, the carbon-based energy storage medium 1 may not be included in one or both of the electrodes 3. That is, in some embodiments, each electrode 3 may be composed only of the current collector 2. The material used to provide the current collector 2 may be roughened, anodized, etc. to increase its surface area. In these embodiments, the current collector 2 may function alone as the electrode 3. However, with this in mind, as used herein, the term "electrode 3" generally refers to the combination of energy storage medium 1 and current collector 2 (but is not limited to this for reasons discussed above).

[0024] At least one form of electrolyte 6 is included in the ultracapacitor 10. The electrolyte 6 fills the void spaces in the electrodes 3 and separators 5 and between the electrodes 3 and separators 5. Generally, the electrolyte 6 is a substance that dissociates into electrically charged ions. A solvent to dissolve the substance may be included optionally in some forms of the electrolyte 6. The electrolyte 6 conducts electricity by ion transport.

[0025] Typically, the storage cells 112 are formed into either a wound or prismatic shape and then packaged within a cylindrical or prismatic housing 7. Once the electrolyte 6 is contained, the housing 7 may be hermetically sealed (or hermetically sealed). In various examples, the package is sealed by techniques using laser, ultrasonic and / or welding techniques. In addition to providing robust physical protection for the storage cells 12, the housing 7 is configured with external contacts for providing electrical communication with respective terminals 8 within the housing 7. Each terminal 8 in turn provides electrical access to the energy stored in the energy storage medium 1, typically through conductors coupled to the energy storage medium 1.

[0026] As discussed herein, "hermetic (or gas-tight seal)" refers to a seal (or sealing) whose quality (i.e., leak rate) is defined in units "atm-cc / sec", which means one cubic centimeter of gas (e.g., He) per second at ambient pressure and temperature. This corresponds to expression in units "standard He-cc / sec". It is further recognized that 1 atm-cc / sec is equal to 1.01325 mbar-L / sec. In general, the ultracapacitor 10 disclosed herein has a leakage current of approximately 5.0×10 -6 A seal having a leak rate of less than or equal to about 5.0×10 -10It may exhibit a leak rate of atm-cc / sec or less. It is also taken into consideration that the performance of a successful seal should be evaluated by the user, designer or manufacturer as appropriate, and that "seal" ultimately refers to a standard that should be defined by the user, designer, manufacturer or other party (or parties).

[0027] Detection of leaks may be accomplished, for example, by the use of a tracer gas. The use of a tracer gas, such as helium, for leak testing is advantageous as it is a dry, fast, accurate and non-destructive method. In one example of this technique, the ultracapacitor 10 is placed in an environment of helium. The ultracapacitor 10 is subjected to pressurized helium. The ultracapacitor 10 is then placed in a vacuum chamber connected to a detector (such as an atomic absorption unit) capable of detecting the presence of helium. By knowing the pressurization time, pressure and internal volume, the leak rate of the ultracapacitor 10 may be determined.

[0028] In some embodiments, at least one lead wire (which may be referred to herein as a "tab") is electrically coupled to a respective one of the current collectors 2. Multiple leads wires (depending on the polarity of the ultracapacitor 10) may be collected together and coupled into respective terminals 8. The terminals 8 may then be coupled to electrical accesses referred to as "contacts" (e.g., one of the housing 7 and the external electrodes (also commonly referred to herein as "feedthroughs" or "pins"). See Figures 28 and 32-34. Consider now the energy storage medium 1 in greater detail.

[0029] In the exemplary ultracapacitor 10, the energy storage medium 1 is formed from carbon nanotubes. The energy storage medium 1 may include other carbonaceous materials, including, for example, activated carbon, carbon fiber, rayon, graphene, aerogel, carbon cloth, and multiple forms of carbon nanotubes. An activated carbon electrode may be produced, for example, by performing a first activation process on a carbon material obtained by carbonization of a carbon compound to produce a carbon-based material, adding a binder to the carbon-based material to produce a formed body, carbonizing the formed body, and finally performing a second activation process on the carbonized formed body to produce an activated carbon electrode. A carbon fiber electrode may be produced, for example, by using paper (or paper) or cloth preformed with carbon fibers having a high surface area.

[0030] In one exemplary method for producing carbon nanotubes, an apparatus for producing a collection of aligned carbon nanotubes includes an apparatus for synthesizing aligned carbon nanotubes on a substrate having a catalyst thereon. The apparatus includes a production unit for performing a production step of creating an environment around the catalyst as a reducing gas environment and heating at least one of the catalyst or the reducing gas; a growth unit for performing a growth step of synthesizing a collection of aligned carbon nanotubes by creating an environment around the catalyst as a raw material gas environment and heating at least one of the catalyst or the raw material gas; and a transfer unit for transferring the substrate from at least the production unit to the growth unit. Various other methods and apparatuses may be utilized to produce a collection of aligned carbon nanotubes.

[0031] In some embodiments, the materials used to form the energy storage medium 1 may include materials other than pure carbon (and various forms of carbon now existing or later devised). That is, various blends of other materials may be included in the energy storage medium 1. More specifically, and in a non-limiting example, at least one binder material may be used in the energy storage medium 1, but this does not imply or require the addition of other materials (such as binder materials). In general, however, the energy storage medium 1 is formed substantially from carbon, and thus may be referred to herein as a "carbonaceous material," "carbonaceous layer," or other similar term. In short, the energy storage medium 1 is formed primarily from carbon, but may include any form of carbon (with any additives or impurities deemed appropriate or acceptable) that provides the desired functionality as the energy storage medium 1.

[0032] In one set of embodiments, the carbonaceous material comprises at least about 60% by weight elemental carbon, and in other embodiments at least about 75%, 85%, 90%, 95% or 98% by weight elemental carbon.

[0033] Carbonaceous materials can include various forms of carbon including carbon black, graphite, etc. Carbonaceous materials can include carbon particles including nanotubes, nanorods, graphene sheets in sheet form, and / or nanoparticles such as graphene sheets shaped into cones, rods, spheres (buckyballs), etc.

[0034] Several embodiments of carbonaceous materials in various forms suitable for use in the energy storage medium 1 are presented herein as examples. These embodiments provide robust energy storage and are well suited for use in the electrode 3. It should be noted that these examples are intended to be illustrative and not limiting of the embodiments of carbonaceous materials suitable for use in the energy storage medium 1.

[0035] In general, the term "electrode" refers to a conductor in a device that may be incorporated into an electrical circuit and that is used to contact another material, often a non-metal. In general, the term "electrode" as used herein refers to a current collector 2 (such as an energy storage medium 1) that may be associated with the current collector 2 and additional components to provide a desired functionality (e.g., an energy storage medium 1 combined with a current collector 2 to provide energy storage and energy transfer). One exemplary method of supplementing an energy storage medium 1 with a current collector 2 to provide an electrode 3 is presented here.

[0036] 2, there is shown a substrate 14 that is a host for carbonaceous material in the form of carbon nanotube aggregates (CNTs). In the embodiment shown, the substrate 14 includes a substrate 17 having a thin layer of catalyst 18 disposed thereon.

[0037] Generally, substrate 14 is made from components that are at least somewhat flexible (i.e., substrate 14 is not brittle) and can withstand the environment for depositing energy storage medium 1 (e.g., CNTs). For example, substrate 14 can withstand a high temperature environment of about 400° C. to about 1,100° C. A variety of materials may be used for substrate 14, as appropriately determined.

[0038] Reference is now made to FIG. 3. Once the energy storage medium 1 (e.g., CNTs) has been fabricated on the substrate 14, the current collector 2 may be placed thereon. In some embodiments, the current collector 2 is about 0.5 micrometers (μm) to about 25 micrometers (μm) thick. In some embodiments, the current collector 2 is about 20 micrometers (μm) to about 40 micrometers (μm) thick. The current collector 2 may appear as a thin layer, such as a layer applied by chemical vapor deposition (CVD), sputtering, e-beam, thermal evaporation, or another suitable technique. In general, the current collector 2 is selected for its properties, such as electrical conductivity, being electrochemically inert, and being compatible with the energy storage medium 1 (e.g., CNTs). Some exemplary materials include aluminum, platinum, gold, tantalum, titanium, and may include other materials and various alloys.

[0039] When the current collector 2 is disposed on the energy storage medium 1 (e.g., CNT), an electrode component 15 is realized. Each electrode component 15 may be used individually as an electrode 3 or may be combined with at least one other electrode component 15 to provide an electrode 3.

[0040] Once the current collector 2 has been fabricated according to the desired criteria, post-fabrication processing may be performed. Exemplary post-treatments include heating and cooling the energy storage medium 1 (e.g., CNT) in a slightly oxidizing environment. After fabrication (and optional post-treatment), a transfer tool may be applied to the current collector 2. See FIG. 4.

[0041] FIG. 4 illustrates the application of a transfer tool 13 to a current collector 2. In this example, the transfer tool 13 is a thermal release tape used in a "dry" transfer method. An exemplary thermal release tape is manufactured by NITTO DENKO CORPORATION (Fremont, Calif. and Osaka, Japan). One suitable release tape is commercially available as REVALPHA. This release tape may be characterized as an adhesive tape that adheres firmly at room temperature and can be peeled off by heating. This tape, and other suitable embodiments of thermal release tapes, will release at a predetermined temperature. Advantageously, the release tape does not leave a chemically active residue on the electrode component 15.

[0042] In another method, called the "wet" transfer method, a tape designed for chemical stripping may be used. Once applied, the tape is removed by immersion in a solvent. The solvent is designed to dissolve the adhesive.

[0043] In other embodiments, the moving tool 13 uses an "aerodynamic" method, such as by applying suction to the current collector 2. The suction may be applied, for example, by a slightly oversized paddle with multiple perforations to distribute the suction. In another example, the suction is applied by a roller with multiple perforations to distribute the suction. Suction-driven embodiments offer the advantage of being electronically controlled and economical since no consumable materials are used as part of the moving process. Other embodiments of the moving tool 13 may be used.

[0044] Once the transfer device 13 is temporarily coupled to the current collector 2, the electrode component 15 is gradually detached from the substrate 14 (see Figures 4 and 5). The detachment typically involves peeling the energy storage medium 1 (e.g., CNTs) from the substrate 14, which begins at one end of the substrate 14 and the energy storage medium 1 (e.g., CNTs).

[0045] The transfer tool 13 may then be separated from the electrode component 15 (see FIG. 6). In some embodiments, the transfer tool 13 is used to attach the electrode component 15. For example, the transfer tool 13 may be used to place the electrode component 15 onto the separator 5. Generally, once removed from the substrate 14, the electrode component 15 is ready for use.

[0046] If a larger electrode 3 is desired, multiple electrode components 15 may be combined. See FIG. 7. As shown in FIG. 7, multiple electrode components 15 may be combined, for example, by connecting a link 52 to each electrode component 15 of the multiple electrode components 15. The combined electrode components 15 provide one embodiment of an electrode 3.

[0047] In some embodiments, the coupling 22 is coupled to each electrode component 15 at a joint (or weld) 21. Each weld 21 may be provided as an ultrasonic joint 21. It has been found that ultrasonic welding techniques are particularly well suited to produce each joint 21. That is, the mass of energy storage medium 1 (e.g., CNT) is generally not amenable to welding, and only nominal current collectors, such as the current collectors disclosed herein, are employed. As a result, many techniques for connecting electrode components 15 are destructive and damage components 15. However, in other embodiments, other forms of coupling are used and coupling 22 is not a joint 21.

[0048] Interconnect 22 may be in the form of a foil, mesh, multiple wires, or other form. Generally, interconnect 22 is selected for properties such as electrical conductivity and being electrochemically inert. In some embodiments, interconnect 22 is made from the same material(s) present in current collector 2.

[0049] In some embodiments, the connections 22 are made by removing an oxide layer from above. The oxide layer may be removed, for example, by etching the connections 22 before providing the joints 21. Etching may be accomplished, for example, with potassium hydroxide (KOH). The electrodes 3 may be used in various embodiments of the ultracapacitor 10. For example, the electrodes 3 may be rolled up into a "jelly roll" type energy store.

[0050] Separator 5 may be made from a variety of materials. In some embodiments, separator 5 is non-woven glass. Separator 5 may also be made from fiberglass, ceramic, fluoropolymers such as polytetrafluoroethylene (PTFE), commonly available as TEFLON® by DuPont Chemicals (Wilmington, Del.). For example, by using non-woven glass, separator 5 may include staple fibers and binder fibers, each of which has a diameter smaller than that of each of the staple fibers, allowing the staple fibers to be bonded together.

[0051] For the life of ultracapacitor 10 and to ensure performance at high temperatures, separator 5 should have a reduced amount of impurities, and in particular, should have a very reduced amount of moisture in separator 5. In particular, it has been found that limiting moisture to about 200 ppm is desirable to reduce chemical reactions and improve the life of ultracapacitor 10, as well as to provide superior performance in high temperature applications. Some embodiments of materials used in separator 5 include polyamide, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), aluminum oxide (Al2O3), fiberglass, and glass reinforced plastic (GRP).

[0052] Generally, the material used for separator 5 is selected according to water content, porosity (or void volume), melting point, impurity content, resulting electrical performance, thickness, cost, availability, etc. In some embodiments, separator 5 is formed from a hydrophobic material.

[0053] Therefore, procedures may be taken to ensure that excess moisture is removed from each separator 5. Vacuum drying may be used, among other techniques. A selection of materials used in separator 5 is presented in Table 1. Some relevant performance data is presented in Table 2.

[0054] [Table 1]

[0055] [Table 2]

[0056] To gather the data in Table 2, two electrodes 3 based on carbonaceous materials were provided. The electrodes 3 were placed opposite and facing each other. Respective separators 5 were placed between the electrodes 3 to prevent short circuits. The three components were then wetted with electrolyte 6 and compressed together. Two aluminum rods (or bars) and PTFE material were used as the outer structure to encase the resulting ultracapacitor 10.

[0057] An ESR first test and an ESR second test were performed in sequence on the same configuration, the second test being performed five minutes after the first test, leaving time for the electrolyte 6 to further soak into the components.

[0058] It should be noted that in some embodiments, the ultracapacitor 10 does not require or include a separator 5. In some embodiments, such as those in which the electrodes 3 are guaranteed to be physically separated by the geometry of the structure, it is sufficient to have only the electrolyte 6 between the electrodes 3. More specifically, and as an example of physical separation, one such ultracapacitor 10 may include the electrodes 3 disposed within a housing such that separation is always guaranteed. A benchtop (or tabletop) example would be an ultracapacitor 10 mounted in a beaker.

[0059] The ultracapacitor 10 may be embodied in a number of different form factors (i.e., may exhibit a particular appearance). Examples of potentially useful form factors include cylindrical cells, ring or annular cells, stacks of flat prismatic cells including flat prismatic cells or box-shaped cells, and flat prismatic cells that are shaped to fit a particular geometry, such as a curved space. Cylindrical form factors may be most useful in conjunction with cylindrical instruments or instruments that attach to cylindrical form factors. Ring or annular form factors may be most useful in conjunction with annular instruments or instruments that attach to annular form factors. Flat prismatic cells shaped to fit a particular geometry may be useful to take advantage of "dead space" (i.e., space in an instrument or facility that may otherwise be unoccupied (or vacant) and not generally accessible).

[0060] Although generally disclosed herein in terms of a "jelly roll" application (i.e., a storage cell 12 configured for a cylindrical housing 7), the rolled storage cell 23 may take any desired shape. For example, folding of the storage cell 12 may be used to provide the rolled storage cell 23, as opposed to rolling the storage cell 12. Other types of assembly may be used. As an example, the storage cell 12 may be a flat cell, referred to as a "coin-shaped" cell. Thus, rolling is only one option for assembling the rolled storage cell 23. Thus, although discussed herein in terms of being a "rolled storage cell 23," it is not intended to be limiting. The term "rolled storage cell 23" may be considered to generally include any suitable shape of packaging or packing of the storage cell 12 to fit within a given design of the housing 7.

[0061] Various configurations of ultracapacitors 10 may be connected together. The various configurations may be connected using known techniques such as welding contacts together, using at least one mechanical connector, providing contacts in electrical contact with each other, etc. Multiple ultracapacitors 10 may be electrically connected in at least one of a parallel and series configuration.

[0062] The electrolyte 6 includes a pair of cations 9 and anions 11 and may include a solvent. The electrolyte 6 may be referred to as an "ionic liquid" if desired. Various combinations of cations 9, anions 11, and solvents may be used. In the exemplary ultracapacitor 10, the cations 9 may include at least one of 1-(3-cyanopropyl)-3-methylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1,3-bis(3-cyanopropyl)imidazolium, 1,3-diethoxyimidazolium, 1-butyl-1-methylpiperidinium, 1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium, 1-butyl-4-methylpyridinium, 1-butylpyridinium, 1-decyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 3-methyl-1-propylpyridinium, and combinations thereof and other equivalents deemed appropriate. Additional exemplary cations 9 include imidazolium, pyrazinium, piperidinium, pyridinium, pyrimidinium, and pyrrolidinium, the structures of which are depicted in Figure 8. In the exemplary ultracapacitor 10, the anion 11 may include at least one of bis(trifluoromethanesulfonate)imide, tris(trifluoromethanesulfonate)methide, dicyanamide, tetrafluoroborate, hexafluorophosphate, trifluoromethanesulfonate, bis(pentafluoroethanesulfonate)imide, thiocyanate, trifluoro(trifluoromethyl)borate, and combinations thereof and other equivalents deemed appropriate.

[0063] The solvent may include acetonitrile, amides, benzonitrile, butyrolactone, cyclic ethers, dibutyl carbonate, diethyl carbonate, diethyl ether, dimethoxyethane, dimethyl carbonate, dimethylformamide, dimethylsulfone, dioxane, dioxolane, ethyl formate, ethylene carbonate, ethyl methyl carbonate, lactones, linear ethers, methyl formate, methyl propionate, methyl tetrahydrofuran, nitriles, nitrobenzene, nitromethane, n-methylpyrrolidone, propylene carbonate, sulfolane, sulfones, tetrahydrofuran, tetramethylene sulfone, thiophenes, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, carbonate esters, gamma-butyrolactone, nitriles, and tricyanohexane, any combination thereof or other material(s) that exhibit suitable performance characteristics.

[0064] 8, various additional embodiments of cations 9 suitable for use in ionic liquids to provide electrolyte 6 are shown. These cations 9 may be used alone or in combination with one another, in combination with at least some of the above-described embodiments of cations 9, or in combination with other cations 9 as a user, designer, manufacturer, or other similar party deems suitable or appropriate. Cations 9 depicted in FIG. 8 include, but are not limited to, ammonium, imidazolium, oxazolium, phosphonium, piperidinium, pyrazinium, pyrazinium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, sulfonium, thiazolium, triazolium, guanidium, isoquinolinium, benzotriazolium, viologen-type, and functionalized imidazolium cations.

[0065] For the cation 9 shown in FIG. 8, various branch groups (R1, R2, R3, ... R x In the case of cation 9, each branching group (R x) can be one of an alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano, hydroxyl, sulfate, sulfonate, or carbonyl group, any of which is optionally substituted.

[0066] The term "alkyl" is art-recognized and may include saturated aliphatic groups, including straight chain alkyl groups, branched chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups. In certain embodiments, a straight chain or branched chain alkyl group has about 20 or fewer carbon atoms in its backbone (e.g., C1-C4 for a straight chain). 20 , C1-C for branched chain 20 Similarly, cycloalkyls have from about 3 to about 10 carbon atoms in their ring structure, or alternatively about 5, 6 or 7 carbons in the ring structure. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, ethylhexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0067] The term "heteroalkyl" is art-recognized and refers to an alkyl group, as described herein, in which one or more atoms is a heteroatom (e.g., oxygen, nitrogen, sulfur, etc.). For example, an alkoxy group (e.g., -OR) is a heteroalkyl group.

[0068] The terms "alkenyl" and "alkynyl" are art-recognized and refer to unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but that contain at least one double or triple bond respectively.

[0069] "Heteroalkenyl" and "heteroalkynyl" are art-recognized and refer to alkenyl and alkynylalkyl groups, as described herein, in which one or more atoms is a heteroatom (eg, oxygen, nitrogen, sulfur, etc.).

[0070] In general, any ion with a negative charge may be used as the anion 11. The selected anion 11 is generally combined with a large organic cation 9 to form a low-temperature molten ionic salt. Room temperature (and lower) molten salts are primarily provided by large anions 9 with a charge of -1. Salts that melt at even lower temperatures are generally realized with anions 11 that have electrons that delocalize easily. Anything that will reduce the affinity between the ions (charge delocalization, distance) will then reduce the melting point. The possible anion configurations are virtually infinite, but only a subset of these will work in low-temperature ionic liquid applications. This is a non-exhaustive overview of possible anion configurations for ionic liquids.

[0071] Common substituents (α) suitable for use in anion 11 presented in Table 3 include: -F - , -Cl - , -Br - , -I - , -OCH3 - , -CN - , -SCN - , -C2H3O2 - , -ClO - , -ClO2 - , -ClO3 - , -ClO4 - , -NCO - , -NCS - , -NCSe - , -NCN - , -OCH(CH3)2 - , -CH2OCH3 - , -COOH - , -OH - , -SOCH3 - , -SO2CH3 - , -SOCH3 - , -SO2CF3 - , -SO3H - , -SO3CF3 - , -O(CF3)2C2(CF3)2O - , -CF3 - , -CHF2 - , -CH2F - , -CH3 -, -NO3 - , -NO2 - , -SO3 - , -SO4 2- , -SF5 - , -CB 11 H 12 - , -CB 11 H6C l6 - , -CH3CB 11 H 11 - , -C2H5CB 11 H 11 - , -A-PO4 - , -A-SO2 - , A-SO3 - , -A-SO3H - , -A-COO - , -A-CO - (wherein A is phenyl (a phenyl group or phenyl ring is a cyclic group of atoms having the formula CH) or substituted phenyl, alkyl (formed by removing a hydrogen atom from an alkane with the general formula C n H 2n+1 (radicals having the formula (I)) or substituted alkyl groups, negatively charged radicals alkanes (alkanes are compounds that consist only of hydrogen and carbon atoms and are joined exclusively by single bonds), halogenated alkanes and ethers (a class of organic compounds that contain an oxygen atom connected to two alkyl or aryl groups).

[0072] Regarding anions 11 suitable for use in the ionic liquid resulting in electrolyte 6, a variety of organic anions 11 may be used. Exemplary anions 11 and their structures are presented in Table 3. In a first embodiment (No. 1), exemplary anions 11 are formulated from the list of substituents (α) presented above or their equivalents. In additional embodiments (No. 2-5 ... n ) and each number of anionic substituents (α1, α2, α3, …α n), where each number of anion substituents (α) may be selected from the list of substitution (α) groups provided above or their equivalents. Note that in some embodiments, multiple anion substituents (α) (i.e., at least one different anion substituent (α)) may be used in any one embodiment of anion 11. Also, note that in some embodiments, base structure (Y) may be a single atom or a designated molecule (listed in Table 3), or its equivalent.

[0073] More specifically, and by way of example, certain combinations may be realized with respect to the exemplary anions presented in Table 3. As an example, in the case of No. 2, the base structure (Y2) comprises a single structure (e.g., an atom or molecule) bonded to two anion substituents (α2). Although shown as having two identical anion substituents (α2), this need not be the case. That is, the base structure (Y2) may be bonded to various anion substituents (α2), such as any of the anion substituents (α) listed above. Similarly, the base structure (Y3), as shown in the case of No. 3, comprises a single structure (e.g., an atom) bonded to three anion substituents (α3). Again, each of the anion substituents (α) included in the anion may be different or diverse, and need not be repeated (repeated or symmetrical) as shown in Table 3. In general, in relation to the notation in Table 3, the subscript in a base structure refers to the number of bonds each base structure may have with the anion substituent (α). That is, each base structure (Y n The subscripts in each anion refer to the anion substituent (α n )

[0074] [Table 3]

[0075] The term "cyano" is given its ordinary meaning in the art and refers to a CN group. The term "sulfate" is given its ordinary meaning in the art and refers to a SO2 group. The term "sulfonate" is given its ordinary meaning in the art and refers to a SO3X group, where X can be an electron pair, hydrogen, alkyl, or cycloalkyl. The term "carbonyl" is art recognized and refers to a C=O group.

[0076] An important aspect of considering the construction of the ultracapacitor 10 is maintaining good chemical hygiene. In various embodiments, to ensure purity of the components, the activated carbon, carbon fiber, rayon, carbon cloth and / or nanotubes that make up the energy storage medium 1 for the two electrodes 3 are dried at elevated (or high) temperatures in a vacuum environment. The separator 5 is also dried at elevated (or high) temperatures in a vacuum environment. Once the electrodes 3 and separator 5 are dried under vacuum, they are packaged in the housing 7 without final sealing or capping in an atmosphere containing less than 50 ppm water. The uncapped ultracapacitor 10 may be dried, for example, over a temperature range of about 100° C. to about 300° C. under vacuum. Once this final drying is complete, the electrolyte 6 may be added in a relatively dry atmosphere (such as an atmosphere having less than about 50 ppm moisture) and the housing 7 is sealed. Of course, other assembly methods may be used and the above provides only a few exemplary aspects of the assembly of the ultracapacitor 10.

[0077] In general, impurities in the electrolyte 6 are kept to a minimum. For example, in some embodiments, the total concentration of halide ions (chloride, bromide, fluoride, iodide) is kept below about 1,000 ppm. The total concentration of metal species (including, for example, Br, Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb, Zn, alloys and oxides thereof) is kept below about 1,000 ppm. Additionally, impurities from solvents and precursors used in the synthesis process are kept below about 1,000 ppm and may include, for example, bromoethane, chloroethane, 1-bromobutane, 1-chlorobutane, 1-methylimidazole, ethyl acetate, methylene chloride, and the like.

[0078] In some embodiments, the impurity content of the ultracapacitor 10 has been measured using an ion selective electrode and Karl Fischer titration method applied to the electrolyte 6 of the ultracapacitor 10. The total halide content in the ultracapacitor 10 according to the teachings herein is less than about 200 ppm halide (Cl - and F - ) and the water content was found to be less than about 100 ppm.

[0079] An example of a technique for producing electrolytes is provided in a reference entitled "The oxidation of alcohols in substituted imidazolium ionic liquids using ruthenium catalysts" (Farmer and Welton, The Royal Society of Chemistry, 2002, No. 4, pp. 97-102). Exemplary processes are also provided herein.

[0080] Impurities can be measured using various techniques, such as atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICPMS), or simplified solubilization and electrochemical detection of traces of heavy metal oxide particles. AAS is a spectroscopic method for the qualitative and quantitative measurement of chemical elements using the absorption of optical radiation (light) by free atoms in the gaseous state. This technique is used to determine the concentration of a particular element (analyte) in the sample to be analyzed. AAS can be used to determine over 70 different elements in solution or directly in solid samples. ICPMS is highly sensitive and can measure up to 10 12 It is a type of mass spectrometry that is capable of determining a range of metals and some nonmetals in concentrations below one part per trillion (ppt). The technique is based on coupling inductively coupled plasma as a method of producing ions (ionization) together with a mass spectrometer as a method of separating and detecting the ions. ICPMS is also capable of monitoring the isotopic separation of suitable ions.

[0081] Additional techniques may be used to analyze impurities. Some of these techniques are particularly convenient for analyzing impurities in solid samples. Ion chromatography (IC) may be used to measure trace levels of halide impurities in electrolytes 6 (e.g., ionic liquids). One advantage of ion chromatography is that the relevant halide species can be measured in a single chromatographic run. A Dionex AS9-HC column with an eluent composed of 20 mM NaOH and 10% (v / v) acetonitrile is one example of an instrument that may be used to quantify halides from ionic liquids. A further technique is X-ray fluorescence.

[0082] X-ray fluorescence (XRF) instruments may be used to measure the halogen content in solid samples. In this technique, the sample to be analyzed is placed in a sample cup, which is then placed in an analyzer where it is irradiated with X-rays of a specific wavelength. The halogen atoms in the sample absorb some of the X-rays and reflect radiation at a wavelength characteristic of the particular halogen. A detector in the instrument then quantifies the amount of radiation returning from the halogen atoms and measures the intensity of the radiation. By knowing the exposed surface area, the halogen concentration in the sample can be determined. A further technique for assessing impurities in solid samples is the pyrolysis technique.

[0083] Adsorption of impurities can be effectively measured by using pyrolysis and a microcoulometer. A microcoulometer can test almost any type of material for total chlorine content. As an example, a small amount of sample (less than 10 milligrams) is injected or placed into a quartz combustion tube where the temperature ranges from about 600°C to about 1,000°C. Pure oxygen is passed through the quartz tube to completely burn off the chlorine-containing components. The resulting combustion products are swept into a titration cell where chloride ions are trapped in an electrolyte solution. The electrolyte solution contains silver ions that immediately combine with the chloride ions and drop out of solution as insoluble silver chloride. A silver electrode in the titration cell electrically replaces the silver ions that are consumed until the silver ion concentration returns to the concentration before the titration began. By recording the amount of current required to generate the required amount of silver, the instrument can determine the amount of chlorine that was present in the original sample. Dividing the total amount of chlorine present by the weight of the sample gives the concentration of chlorine actually present in the sample. Other techniques for evaluating impurities may be used.

[0084] The surface characterization and water content in the electrode 3 may be analyzed by, for example, infrared spectroscopy techniques. -1 The four main absorption bands in the vicinity correspond to νC=O, νC=C in aryl, νO-H and νC-N, respectively. By measuring the intensities and peak positions, it is possible to quantitatively identify surface impurities in the electrode 3.

[0085] Another technique for identifying impurities in the electrolyte 6 and ultracapacitor 10 is Raman spectroscopy. This spectroscopic technique relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons, or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. Thus, this technique may be used to characterize the atoms and molecules within the ultracapacitor 10. Numerous variations of Raman spectroscopy may be used and prove useful in characterizing the contents of the ultracapacitor 10.

[0086] Once constructed, ultracapacitor 10 may be used in high temperature applications with little or no leakage current and little increase in resistance. Ultracapacitor 10 described herein can operate effectively at temperatures from about -40°C to about 210°C, with leakage current normalized to device volume of less than 1 ampere per liter (1A / L) of device volume throughout the entire operating voltage and temperature range.

[0087] By reducing the water content in ultracapacitor 10 (e.g., to less than 500 ppm by weight and volume of the electrolyte and less than 1,000 ppm of impurities), ultracapacitor 10 can operate effectively over a range of temperatures with a leakage current (I / L) of less than 1,000 milliamps per liter within that temperature and voltage range.

[0088] In one embodiment, the leakage current (I / L) at a particular temperature is measured by holding the voltage of ultracapacitor 10 constant at the rated voltage (i.e., maximum rated operating voltage) for 72 hours. During this time, the temperature remains relatively constant at the particular temperature. At the end of the measurement interval, the leakage current of ultracapacitor 10 is measured.

[0089] In some embodiments, the maximum rated voltage of ultracapacitor 10 is about 4 V at room temperature. A means of ensuring performance of ultracapacitor 10 at high temperatures (e.g., above 210° C.) is to reduce the output level (i.e., lower the rated voltage) of ultracapacitor 10. For example, the rated voltage may be adjusted down to about 0.5 V to achieve an extended duration of operation at high temperatures.

[0090] Another embodiment for ensuring a high degree of purity includes an exemplary method for purifying electrolyte 6. Although the method is presented with respect to specific parameters (e.g., amounts, compositions, times, etc.), it should be noted that the presentation is merely exemplary and illustrative of a method for purifying an electrolyte, and is not intended to be limiting.

[0091] In the first step of the electrolyte purification process, electrolyte 6 (in some embodiments, an ionic liquid) is mixed with deionized water and then heated to a moderate temperature for some time. In a proof of concept, 50 milliliters (ml) of ionic liquid was mixed with 850 milliliters (ml) of deionized water. The mixture was heated to a constant temperature of 60° C. and subjected to constant stirring (about 120 revolutions per minute (rpm)) for about 12 hours.

[0092] In the second step, the mixture of ionic liquid and deionized water is allowed to separate. In this example, the mixture was transferred through a funnel and allowed to sit for approximately 4 hours.

[0093] In the third step, the ionic liquid is collected. In this example, the aqueous phase of the mixture was at the bottom and the ionic liquid phase was at the top. The ionic liquid phase was transferred to a separate beaker.

[0094] In the fourth step, the solvent was mixed with the ionic liquid. In this example, a volume of about 25 milliliters (ml) of ethyl acetate was mixed with the ionic liquid. The mixture was again heated to a suitable temperature (or medium temperature) and stirred for a period of time.

[0095] Although ethyl acetate was used as the solvent, the solvent could be at least one of diethyl ether, pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, 1-4 dioxane, chloroform or any combination of these and other material(s) that exhibit suitable performance characteristics. Some of the desired performance characteristics include non-polar solvent performance characteristics and a high degree of volatility.

[0096] In the fifth step, carbon powder is added to the mixture of ionic liquid and solvent. In this example, about 20 weight percent (wt%) of carbon (diameter about 0.45 micrometers) was added to the mixture.

[0097] In a sixth step, the ionic liquid is mixed again. In this example, the mixture containing the carbon powder was subjected to constant stirring (120 rpm) at about 70° C. overnight.

[0098] In the seventh step, the carbon and ethyl acetate are separated from the ionic liquid. In this example, the carbon was separated using Buchner filtration using a glass microfiber filter. Multiple (three) filtrations were performed. The collected ionic liquid was then passed through a 0.2 micrometer syringe filter to remove substantially all carbon particles. In this example, the solvent was then substantially separated from the ionic liquid by using rotary evaporation (or rotary evaporation). Specifically, a sample of the ionic liquid was stirred while increasing the temperature from 70° C. to 80° C., and finished at 100° C. Evaporation was performed for approximately 15 minutes at each temperature.

[0099] The electrolyte purification method proved to be very effective. For the ionic liquid samples, the water content was measured by titration using a titration device provided by Mettler-Toledo Inc. (Columbus, OH, Model No.: AQC22). The halide content was measured using an ISE (Ion Selective Electrode) instrument provided by Hanna Instruments (Woonsocket, RI, Model No.: AQC22). Standard solutions for the ISE instrument were obtained from Hanna and included HI 4007-03 (1,000 ppm chloride standard), HI 4010-03 (1,000 ppm fluoride standard), HI 4000-00 (ISA for halide electrodes) and HI 4010-00 (TISAB solution for fluoride electrodes only). Prior to performing the measurements, the ISE instrument was calibrated using standard solutions with 0.1, 10, 100 and 1,000 ppm standards mixed with deionized water. Cl - For ion determination, ISA buffer was added to the standards in a ratio of 1:50. The results are shown in Table 4.

[0100] [Table 4]

[0101] A four-step method was used to measure the halide ions. First, Cl - and F - The Cl ions were measured in deionized water. Next, 0.01 M solutions of the ionic liquids were prepared using deionized water. - and F - The ions were measured in the solution, and an estimate of the halide content was then determined by subtracting the amount of ions in the water from the amount of ions in the solution.

[0102] As an overview, a method for assembling a cylindrical ultracapacitor 10 is presented. Starting with the electrodes 3, each electrode 3 is fabricated after the energy storage medium 1 is associated with a current collector 2. A number of leads are then connected to appropriate locations of each electrode 3. The electrodes 3 are then aligned and assembled with an appropriate number of separators disposed therebetween to form a storage cell 12. The storage cell 12 may then be rolled into a cylindrical shape and secured with a wrapper. Typically, each lead is then bundled to form a respective terminal 8.

[0103] Prior to incorporating electrolyte 6 into ultracapacitor 10 (e.g., before or after assembly of the storage cell), the components of ultracapacitor 10 may be dried to remove moisture. This may be done with unassembled components (i.e., empty housing 7 and each of the electrodes 3 and separators 5) or it may be done subsequently with assembled components (such as storage cell 12).

[0104] Drying may occur at elevated temperatures, for example, in a vacuum environment. Once dried, the storage cells 12 may then be packaged in the housing 7 without final sealing or capping. In some embodiments, packaging occurs in an atmosphere containing less than 50 ppm water. The uncapped ultracapacitor 10 may then be dried again. For example, the ultracapacitor 10 may be dried under vacuum over a temperature range of about 100° C. to about 300° C. Once this final drying is complete, the housing 7 may then be sealed, for example, in an atmosphere having less than 50 ppm moisture.

[0105] In some embodiments, once the drying process (which may be referred to as a "baking" process) is complete, the environment around the components may be flooded with an inert gas. Exemplary gases include argon, nitrogen, helium, and other gases exhibiting similar properties (as well as combinations thereof).

[0106] Typically, a fill port (a perforation in the surface of the housing 7) may be included in the housing 7 or added later. Once the ultracapacitor 10 is filled with electrolyte 6, the fill port may be closed. Closing of the fill port may be accomplished, for example, by welding a material (e.g., a metal that is compatible with the housing 7) into or onto the fill port. In some embodiments, the fill port may be temporarily closed prior to filling such that the ultracapacitor 10 may be moved to another environment for subsequent reopening, filling, and closing. Although, as discussed herein, it is contemplated that the ultracapacitor 10 is dried and filled (or filled) in the same environment.

[0107] A number of methods may be used to fill the housing 7 with the desired amount of electrolyte 6. In general, control of the filling method may result in, among other things, increasing capacitance, lowering equivalent series resistance (ESR), and limiting depletion of electrolyte 6. A vacuum filling method is presented as a non-limiting example of a technique for filling the housing 7 with electrolyte 6 and wetting the storage cell 12 with electrolyte 6.

[0108] However, it should be noted that first, measures may be taken to ensure that materials that may contaminate the components of ultracapacitor 10 are clean, compatible, and dry. Conventionally, it may be considered that "good hygiene" is performed to ensure the assembly process and components do not introduce contaminants to ultracapacitor 10. It may also be conventionally considered that a "contaminant" may be defined as any undesirable material that, if introduced, would adversely affect the performance of ultracapacitor 10. It should also be noted that generally herein, contaminants may be evaluated as concentrations such as ppm. Concentrations may be considered as a weight basis, a volume basis, a sample weight basis, or in any other manner determined to be appropriate.

[0109] In the "vacuum method," a container is placed around the inlet on the housing 7. A quantity of electrolyte 6 is then placed into the container in an environment that is substantially free of oxygen and water (i.e., moisture). A vacuum is then drawn on the environment, thereby drawing air from the housing and simultaneously drawing the electrolyte 6 into the housing 7. The surrounding environment may then be replenished with an inert gas (argon, nitrogen, etc., or some combination of inert gases) as needed. The ultracapacitor 10 may be checked to see if the desired amount of electrolyte 6 has been drawn in. The method may be repeated as necessary until the desired amount of electrolyte 6 is present in the ultracapacitor 10.

[0110] After filling with electrolyte 6, in some embodiments, a material may be fitted to the fill port to seal the ultracapacitor 10. The material may be, for example, a metal that is compatible with the housing 7 and electrolyte 6. In one example, the material is force fit into the fill port, essentially performing a "cold weld" of the plug at the fill port. Of course, the force fit may be supplemented with other welding techniques, as discussed further herein.

[0111] To demonstrate how the filling method results in ultracapacitor 10, two similar embodiments of ultracapacitor 10 were constructed. One was filled without a vacuum and the other was filled under vacuum. The electrical performance of the two embodiments is presented in Table 5. Upon repeated performance of such measurements, it was noted that improved performance was realized by filling ultracapacitor 10 by applying a vacuum. In general, it was determined that it is desirable to reduce the pressure within housing 7 to less than about 150 milliTorr (mTorr), and particularly to less than about 40 mTorr.

[0112] [Table 5]

[0113] To evaluate the effectiveness of the vacuum filling technique, two different pouch type cells were tested. The pouch type cells contained two electrodes 3, each electrode 3 based on a carbonaceous material. Each of the electrodes 3 were positioned opposite and facing each other. A separator 5 was placed between them to prevent short circuits, and all were immersed in the electrolyte 6. Two external tabs were used to provide four measurement points. The separator 5 used was a polyethylene separator 5, and the cell had a total volume of about 0.468 ml.

[0114] Figure 9 represents the leakage current for unpurified electrolyte in ultracapacitor 10. Figure 10 represents the leakage current for purified electrolyte in a similarly calibrated ultracapacitor 10. It can be seen that there is a significant drop in leakage current initially and then over the later portion of the measurement interval. Further information is provided in the configuration of each embodiment in Table 6.

[0115] [Table 6]

[0116] Leakage current may be determined in a number of ways. Quantitatively, leakage current may be considered to be the current drawn by the device once it has reached an equilibrium state. In practice, it is always or almost always necessary to estimate the actual leakage current as an equilibrium state that may generally only be reached asymptotically. Thus, the leakage current for a given measurement may be estimated by measuring the current drawn by the ultracapacitor 10 while holding the ultracapacitor 10 at a substantially fixed voltage and exposing it to a substantially fixed ambient temperature for a relatively long time. In some instances, a "relatively long time" may be determined by approximating the current-time function as an exponential function, over which a number of characteristic time constants (e.g., about 3-5) may elapse. In many cases, such durations are in the range of about 50 hours to about 100 hours for many ultracapacitor technologies. Alternatively, if such long times are impractical for some reason, the leakage current may be simply extrapolated, again perhaps by approximating the current-time function as an exponential function or any approximation deemed appropriate. In particular, the leakage current will generally depend on the ambient temperature. Therefore, to characterize the performance of a device at a temperature or range of temperatures, it is generally important to expose the device to the ambient temperature of interest when measuring the leakage current.

[0117] Reference is now made to Figure 11, which illustrates one exemplary embodiment of housing 7. Among other things, housing 7 provides structure and physical protection for ultracapacitor 10. In this example, housing 7 includes an annular cylindrical body 20 and a complementary cap 24. In this embodiment, cap 24 includes a center portion that is removed and filled with electrical insulator 26. A feed-through 19 in the cap penetrates electrical insulator 26 to provide a user with access to the stored energy.

[0118] Common materials for the housing 7 include stainless steel, aluminum, tantalum, titanium, nickel, copper, tin, various alloys, laminates, etc. Other structural materials, such as some polymer-based materials, may be used for the housing 7 (generally in combination with at least some metallic components).

[0119] Although this example depicts only one feedthrough 19 in the cap 24, it should be understood that the structure of the housing 7 is not limited to the embodiments discussed herein. For example, the cap 24 may include multiple feedthroughs 19. In some embodiments, the body 20 includes a second similar cap 24 at an opposite end of the annular cylinder. Furthermore, it should be understood that the housing 7 is not limited to embodiments having an annular cylindrical body 20. For example, the housing 7 may be a shell (or clamshell) type, a prismatic type, a pouch type, or any other type suitable for the needs of a designer, manufacturer, or user.

[0120] In this example, the cap 24 is made to have an outer diameter designed to closely fit the inner diameter of the body 20. Upon assembly, the cap 24 may be welded into the body 20, thereby providing a tight seal for the user.

[0121] Referring now to FIG. 12, an exemplary energy storage cell 12 is shown. In this example, the energy storage cell 12 is a "jelly roll" type energy storage. In these embodiments, the energy storage material is rolled into a solid package. A plurality of leads generally form each terminal 8 and provide electrical access to the appropriate layers of the energy storage cell 12. Generally, when assembled, each terminal 8 is electrically coupled to the housing 7 (e.g., to a respective feedthrough 19 and / or directly to the housing 7). The energy storage cell 12 may assume a variety of configurations. Generally, there are at least two plurality of leads (e.g., terminals 8), one to each current collector 2. For simplicity, only one of the terminals 8 is shown in FIGS. 12, 15 and 17.

[0122] A high quality seal of the housing 7 is desirable, i.e., preventing ingress of the external environment (air, moisture, etc.), helps maintain the purity of the components of the energy storage cell 12. In addition, this prevents leakage of the electrolyte 6 from the energy storage cell 12.

[0123] 13, the housing 7 may include an inner barrier 30. In some embodiments, the barrier 30 is a coating. In this example, the barrier 30 is formed from polytetrafluoroethylene (PTFE). Polytetrafluoroethylene (PTFE) exhibits a variety of properties that make this composition well suited for the barrier 30. PTFE has a melting point of about 327° C., has excellent dielectric properties, has a coefficient of friction of about 0.05-0.10 (which is the third lowest of any known solid material), has high corrosion resistance, and other beneficial properties. In general, the interior of the cap 24 may include a barrier 30 disposed therein.

[0124] Other materials may be used for the barrier 30. These other materials are in the form of, among others, ceramics (any type of ceramic that can be suitably applied and meet the performance criteria), other polymers (preferably high temperature polymers), etc. Exemplary other polymers include perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP) and ethylene tetrafluoroethylene (ETFE).

[0125] The barrier 30 may include any material or combination of materials that results in a reduction in electrochemical or other types of reactions between the energy storage cells 12 and the housing 7 or components of the housing 7. In some embodiments, the combination is shown as a uniform dispersion of different materials in a single layer. In other embodiments, the combination is shown as different materials in multiple layers. Other combinations may be used. In short, the barrier 30 may be considered to be at least one of an electrical insulator and chemically inert (i.e., exhibiting low reactivity), and thus substantially withstands or prevents at least one of electrical and chemical interaction between the storage cells 12 and the housing 7. In some embodiments, the terms "low reactivity" and "low chemical reactivity" generally refer to a rate of chemical interaction that is lower than a level of interest to the practitioner.

[0126] Generally, the interior of the housing 7 may be host to a barrier 30 such that all surfaces of the housing 7 exposed to the interior are coated. At least one untreated area 31 may be included within the body 20 and on the exterior surface 36 of the cap 24 (see FIG. 14A). In some embodiments, the untreated area 31 (see FIG. 14B) may be included to accommodate assembly requirements, such as areas that will be sealed or connected (such as by welding).

[0127] The barrier 30 may be applied internally using conventional techniques. For example, in the case of PTFE, the barrier 30 may be applied by painting or spraying the barrier 30 onto the internal surface as a coating. A mask may be used as part of the process to ensure that the untreated areas 31 remain in the desired integrity. In short, a variety of techniques may be used to provide the barrier 30.

[0128] In one exemplary embodiment, the barrier 30 is about 3 mils to about 5 mils thick, while the material used for the barrier 30 is a PFA-based material. In this example, the surface that will receive the material that will make up the barrier 30 is prepared by grit blasting with aluminum oxide or the like. Once the surface is cleaned, the material is applied first as a liquid and then as a powder. The material is hardened by a heat treatment process. In some embodiments, the heating cycle is at a temperature of about 370° C. and has a duration of about 10 minutes to about 15 minutes. This results in a continuous finish of the barrier 30 that is substantially free of pinhole-sized or smaller defects. FIG. 15 illustrates the assembly of one embodiment of an ultracapacitor 10 in accordance with the teachings herein. In this embodiment, the ultracapacitor 10 includes a body 20 including the barrier 30 disposed therein, a cap 24 with the barrier 30 disposed therein, and an energy storage cell 12. During assembly, the cap 24 is placed over the body 20. One terminal 8 is electrically coupled to a feedthrough 19 in the cap, while the second terminal 8 is electrically coupled to the housing 7, typically at the bottom, side or top of the cap 24. In some embodiments, the second terminal 8 is coupled to another feedthrough 19 (such as in the opposite cap 24).

[0129] With barrier 30 disposed on the interior surface(s) of housing 7, electrochemical and other reactions between housing 7 and the electrolyte are greatly reduced or substantially eliminated, especially at elevated temperatures where the rates of chemical and other reactions generally increase.

[0130] Referring now to FIG. 16, the relative performance of ultracapacitor 10 compared to other comparable ultracapacitors is shown. In FIG. 16A, the leakage current is shown for a prior art embodiment of ultracapacitor 10. In FIG. 16B, the leakage current is shown for a comparable ultracapacitor 10 including a barrier 30. In FIG. 16B, the ultracapacitor 10 is electrically comparable to the ultracapacitor whose leakage current is shown in FIG. 16A. In both cases, the housing 7 is stainless steel, the voltage supplied to the cell was 1.75 volts, and the electrolyte was unpurified. The temperature was held constant at 150° C. Notably, the leakage current in FIG. 16A shows a relatively high initial value and a substantial increase over time, whereas the leakage current in FIG. 16B shows a relatively low initial value and does not show a substantial increase over time.

[0131] In general, the barrier 30 comprises a suitable thickness of a suitable material between the energy storage cells 12 and the housing 7. The barrier 30 may include a homogeneous mixture, a non-homogeneous mixture, and / or at least one layer of material. The barrier 30 may provide complete coverage (i.e., coverage over the interior surface area of ​​the housing excluding the electrode contacts) or may provide partial coverage. In some embodiments, the barrier 30 is formed from multiple components. For example, consider the example presented below and illustrated in FIG. 8.

[0132] Referring to FIG. 17, additional embodiment aspects are shown. In some embodiments, the energy storage cell 12 is placed within an envelope (or packaging) 33. That is, the energy storage cell 12 has a barrier 30 placed over, covered over, or otherwise applied to separate the energy storage cell 12 from the housing 7 upon assembly. The envelope 33 may be applied well prior to packaging the energy storage cell 12 within the housing 7. Thus, the use of the envelope 33 may present certain advantages to manufacturers and the like. (Note that for purposes of illustration, the envelope 33 is shown as being loosely (or loosely) placed over the energy storage cell 12.)

[0133] In some embodiments, the envelope 33 is used in conjunction with a coating, where the coating is disposed on at least a portion of the interior surface. For example, in one embodiment, the coating is disposed only in areas of the interior of the housing 7 where the envelope 33 may be at least partially exposed to a hazard (such as a protruding terminal 8). The envelope 33 and coating together form an effective barrier 30.

[0134] Thus, the incorporation of barrier 30 may provide an ultracapacitor that exhibits a leakage current having a relatively low initial value and a substantially slow increase in leakage current over time in consideration of the prior art. Significantly, the leakage current of the ultracapacitor remains at a practical (i.e., desirably low) level when the ultracapacitor is exposed to ambient temperatures where prior art capacitors would exhibit a very high initial value of leakage current and / or a very fast increase in leakage current over time.

[0135] Conventionally, the term "leakage current" generally refers to the current drawn by a capacitor measured after a predetermined time. This measurement is made when the terminals of the capacitor are held at a substantially fixed potential difference (terminal voltage). A typical time is 72 hours when evaluating leakage current, but different times may be used. It is noted that leakage current for prior art capacitors generally increases with increasing volume and surface area of ​​the energy storage medium and the associated increase in surface area inside the housing. In general, an increase in leakage current is believed to indicate a gradual increase in the reaction rate within the ultracapacitor 10. The performance requirements for leakage current are generally defined by the environmental conditions prevailing in a particular application. For example, for an ultracapacitor 10 with a volume of 20 mL, the practical limit for leakage current may be below 100 mA.

[0136] Having thus described an embodiment of the barrier 30 and its various aspects, it should be understood that the ultracapacitor 10 may exhibit other benefits as a result of reducing reactions between the housing 7 and the energy storage medium 1. For example, the equivalent series circuit (ESR) of the ultracapacitor 10 may exhibit a relatively low value over time. Furthermore, unwanted chemical reactions occurring in prior art capacitors often result in unwanted effects such as out-gassing, or in the case of sealed housings, swelling of the housing. In both cases, this compromises the structural integrity of the housing and / or the sealing of the capacitor. Ultimately, this may result in leakage or catastrophic failure of prior art capacitors. In some embodiments, these effects may be substantially reduced or eliminated by application of the disclosed barrier 30.

[0137] It should be understood that the terms "barrier" and "coating" are not limited to the teachings herein. That is, any technique for applying a suitable material to the interior of the housing 7, body 20 and / or cap may be used. For example, in other embodiments, the barrier 30 is actually fabricated in or on the material that constitutes the housing body 20, which is then processed or shaped as necessary to form the various components of the housing 7. In considering some of the many possible techniques for applying the barrier 30, it may be equally suitable to apply the material(s) by roller coating, sputtering, sintering, laminating, printing or other methods. In short, the barrier 30 may be applied using any technique deemed appropriate by the manufacturer, designer and / or user.

[0138] The materials used in barrier 30 may be selected according to properties such as reactivity, dielectric value, melting point, adhesion to the material of housing 7, coefficient of friction, cost, and other such factors. Combinations of materials (e.g., laminated, mixed, or otherwise combined) may be used to provide desired properties.

[0139] By using an improved housing 7, such as a housing 7 with a barrier 30, degradation of the electrolyte 6 may be limited in some embodiments. The barrier 30 represents one technique for providing an improved housing 7, although other techniques may be used. For example, the use of a housing 7 made from aluminum would be advantageous due to the electrochemical properties of aluminum in the presence of the electrolyte 6. However, given the difficulty of manufacturing aluminum, it has not (until now) been possible to construct an embodiment of the housing 7 utilizing aluminum.

[0140] Additional embodiments of the housing 7 include those that provide aluminum on all interior surfaces that may be exposed to the electrolyte while providing the user with the ability to weld and seal the housing. Improved performance of the ultracapacitor 10 may be achieved due to reduced internal corrosion, elimination of problems associated with the use of dissimilar metals in a conductive medium, and for other reasons. Advantageously, the housing 7 utilizes existing technology, available electrode inserts, including glass-to-metal seals (or closures or hermetics) (and may include those made from stainless steel, tantalum, or other convenient materials and components), and is therefore economical to manufacture.

[0141] Although disclosed herein as embodiments of housing 7 suitable for ultracapacitor 10, these embodiments (as well as barrier 30) may be used with any type of energy storage deemed suitable and may include any type of operable technology. For example, other forms of energy storage may be used, including electrochemical batteries, particularly lithium-based batteries.

[0142] In some embodiments, the material used in the construction of the body 20 includes aluminum, which may include any type of aluminum or aluminum alloy (all of which are generally referred to herein simply as "aluminum") as the designer or manufacturer deems appropriate. Various alloys, laminates, and the like may be disposed (e.g., coated) over the aluminum (the aluminum exposed on the interior of the body 20). Additional materials (such as structural materials or electrically insulating materials such as some polymer-based materials) may be used to supplement the body and / or housing 7. Materials disposed over the aluminum may likewise be selected as the designer or manufacturer deems appropriate.

[0143] Generally, the material(s) exposed inside the housing 7 will exhibit sufficiently low reactivity when exposed to the electrolyte 6 and thus are merely illustrative of some of the embodiments and are not limited to the teachings herein.

[0144] While this example depicts only one feedthrough 19 in the cap 24, it should be understood that the structure of the housing 7 is not limited to the embodiments discussed herein. For example, the cap 24 may include multiple feedthroughs 19. In some embodiments, the body 20 includes a second similar cap 24 at an opposite end of the annular cylinder. Furthermore, it should be understood that the housing 7 is not limited to embodiments having an annular cylindrical body 20. For example, the housing 7 may be shell-shaped, prismatic, pouch-shaped, or any other design suitable to the needs of a designer, manufacturer, or user.

[0145] A high quality seal of the housing 7 is desirable, i.e., preventing ingress of the outside environment (e.g., air, moisture, etc.) helps maintain the purity of the components of the energy storage cell 12. In addition, this prevents leakage (or leakage) of the electrolyte 6 from the energy storage cell 12.

[0146] Referring now to FIG. 18, aspects of an embodiment of the blank 34 of the cap 24 are shown. In FIG. 18A, the blank 34 comprises a multi-layer material. A first layer of material 41 is aluminum. A second layer of material 42 is stainless steel. In the embodiment of FIG. 18, the stainless steel is clad onto the aluminum, thereby resulting in a material that exhibits a desired combination of metallurgical properties. That is, in the embodiment presented herein, the aluminum is exposed to the interior of the energy storage cell (i.e., the housing), while the stainless steel is exposed to the exterior. In this way, the favorable electrical properties of the aluminum are preserved, while the structural properties (and metallurgical properties, i.e., weldability) of the stainless steel provide reliability for the structure. The multi-layer material may include additional layers as deemed appropriate.

[0147] As mentioned above, a layer of a first material 41 is clad over (or with) a layer of a second material 42. As used herein, the terms "clad", "coating" and the like refer to bonding dissimilar metals together. Cladding is often accomplished by extruding the two metals through a die (or mold) and pressing or rolling the sheets together under high pressure. Other processes such as laser cladding may be used. The result is a sheet of material made up of multiple layers, the multiple layers of material being bonded together such that the material can act as a single sheet (e.g., formed such that a single layer of uniform material is formed).

[0148] 18A, in one embodiment, a flat sheet of metal stock (as shown) is used to provide a blank 34 for making a flat cap 24. A portion of the layer of second material 42 may be removed (such as around the periphery of the cap 24) to facilitate attachment of the cap 24 to the body 20. In FIG. 18B, another embodiment of the blank 34 is shown. In this example, the blank 34 is provided as a sheet of cladding material formed into a concave configuration. In FIG. 18C, the blank 34 is provided as a sheet of cladding material formed into a convex configuration. Caps 24 made from various embodiments of the blank 34 (such as the embodiment shown in FIG. 18) are configured to support welding to the body 20 of the housing 7. More specifically, the embodiment of FIG. 18B is adapted to fit within the inner diameter of the body 20, while the embodiment of FIG. 18C is adapted to fit onto the surface of the outer diameter of the body 20. In various alternative embodiments, the layers of cladding material within the sheet may be reversed.

[0149] Upon assembly, the cap 24 may be joined to the body 20, thereby providing a hermetic seal to the user. Exemplary welding techniques include laser welding and TIG (or TIG) welding, and may include other forms of welding as deemed appropriate.

[0150] 19, one embodiment of an electrode assembly (or electrode subassembly) 50 is shown. The electrode assembly 50 is designed to be mounted within the blank 34 and to provide electrical communication from the energy storage medium to the user. In general, the electrode assembly 50 includes a sleeve 51. The sleeve 51 surrounds the insulator 26, which in turn surrounds the feedthrough 19. In this example, the sleeve 51 is an annular cylinder with a flanged (or collared) top.

[0151] To assemble the cap 24, a drill hole (not shown) is formed in the blank 34. The drill hole has a size and geometry that matches the electrode assembly 50. The electrode assembly 50 is then inserted into the drill hole in the blank 34. Once the electrode assembly 50 is inserted, it may be attached to the blank 34 by a technique such as welding. The welding may be a laser weld around the outer periphery of the flange of the sleeve 51. With reference to FIG. 20, a location (or point) 61 at which the weld is performed is shown. In this embodiment, the location 61 provides a suitable location for welding stainless steel to stainless steel, providing a relatively simple welding procedure. Thus, the teachings herein provide a secure welding of the electrode assembly 50 into place in the blank 34.

[0152] The materials that make up the sleeve 51 may include various types of metals or metal alloys. In general, the materials of the sleeve 51 are selected according to, for example, structural integrity (or conformity) and bondability (to the blank 34). Exemplary materials for the sleeve 51 include 304 stainless steel or 316 stainless steel. The materials that make up the feedthrough 19 may include various types of metals or metal alloys. In general, the materials of the feedthrough 19 are selected according to, for example, structural integrity and electrical conductance. Exemplary materials for the electrodes include 446 stainless steel or 52 alloy.

[0153] Typically, the insulator 26 is bonded to the sleeve 51 and the feedthrough 19 by known techniques (i.e., glass-to-metal bonding). The materials that make up the insulator 26 may include various types of glasses, including, but are not limited to, high temperature glasses, ceramic glasses, or ceramic materials. Typically, the insulator material is selected according to, for example, structural integrity and electrical resistance (i.e., electrical insulation).

[0154] The use of components that rely on glass-metal bonding (such as the above-described embodiment of the electrode assembly 50) and the use of various welding techniques provide a hermetic seal for the energy storage body. Other components may be used to provide a hermetic seal as well. As used herein, the term "hermetic seal" generally refers to a seal that exhibits a leak rate equal to or less than the leak rate defined herein, although it is believed that the effectiveness of the actual seal may perform better than this criterion.

[0155] Additional or alternative techniques for joining the electrode assembly 50 to the blank 34 include using a bonding agent under the flange of the sleeve 51 (between the flange and the second layer of material 42), if such a technique is deemed appropriate.

[0156] 21 , the energy storage cell 12 is disposed within a body 20. At least one terminal 8 is appropriately connected (such as to a feedthrough 19) and a cap 24 is bonded to the body 20 to provide the ultracapacitor 10.

[0157] Once assembled, the cap 24 and the body 20 may be sealed. FIG. 22 depicts various embodiments of an assembled energy storage body (in this case, the ultracapacitor 10). In FIG. 22A, a flat blank 34 (see FIG. 18A) is used to make a flat cap 24. Once the cap 24 is placed on the body 20, the cap 24 and the body 20 are welded to form a seal 62. In this case, since the body 20 is an annular cylinder, the welding proceeds around the circumference of the body 20 and the cap 24. In a second embodiment shown in FIG. 22B, a concave blank 34 (see FIG. 18B) is used to make a concave cap 24. Once the cap 24 is placed on the body 20, the cap 24 and the body 20 are welded to form a seal 62. In a third embodiment shown in FIG. 22C, a convex blank 34 (see FIG. 18C) is used to make a convex cap 24. Once the cap 24 is installed on the body 20 , the cap 24 and body 20 may be welded together to form a seal 62 .

[0158] If desired, the cladding (or coating) may be removed (e.g., by techniques such as machining or etching) to expose other metals in the multi-layer material. Thus, in some embodiments, the seal 62 may include an aluminum-to-aluminum weld. The aluminum-to-aluminum weld may be supplemented with other fasteners, if desired.

[0159] Other techniques may be used to seal housing 7, such as laser welding, TIG welding, resistance welding, ultrasonic welding, and other forms of mechanical seals, although it should be noted that conventional forms of mechanical seals are generally not sufficient alone to provide the robust seal exhibited in ultracapacitor 10.

[0160] In some embodiments, multi-layer materials are used for the internal components. For example, aluminum may be clad with stainless steel to provide a multi-layer material in at least one of the terminals 8. In some of these embodiments, a portion of the aluminum may be removed to expose the stainless steel. The exposed stainless steel may then be used to attach the terminal 8 to the feedthrough 19 using a simple welding procedure.

[0161] The use of clad materials for internal components may require specific embodiments of the clad material. For example, it may be advantageous to use clad materials that include aluminum (bottom layer), stainless steel and / or tantalum (middle layer) and aluminum (top layer), thereby limiting exposure of the stainless steel to the internal environment of ultracapacitor 10. These embodiments may be augmented with additional coatings, for example with polymeric materials such as PTFE.

[0162] In general, assembly of the housing often involves placing the storage cells 12 into the body 20 and filling (or charging) the body 20 with the electrolyte 6. A drying step may be performed. Exemplary drying includes heating the body 20 with the storage cells 12 and electrolyte 6 therein, often under reduced pressure (e.g., vacuum). Once sufficient (optional) drying has occurred, the final steps of assembly may be performed, including forming internal electrical connections, attaching the cap 24, and sealing the cap 24 to the body 20, for example, by welding the cap 24 to the body 20.

[0163] Thus, providing a housing 7 utilizing a multi-layer material results in an energy store that exhibits a relatively low initial value of leakage current and a substantially slower increase in leakage current over time given the prior art. Significantly, the leakage current of the energy store remains at a practical (i.e., desirably low) level when the ultracapacitor 10 is exposed to ambient ranges where prior art capacitors exhibit very high initial values ​​of leakage current and / or very fast increases in leakage current over time.

[0164] Additionally, the ultracapacitor 10 may offer other benefits as a result of reduced reactions between the housing 7 and the energy storage cells 12. For example, the equivalent series resistance (ESR) of the energy storage medium may exhibit a relatively low value over time. Furthermore, unwanted chemical reactions that take place in prior art capacitors often result in unwanted effects such as outgassing or, in the case of sealed housings, bulging of the housing 7. In both cases, this results in a compromise of the structural integrity of the housing 7 and / or the sealing of the energy storage. Ultimately, this can result in leakage or catastrophic failure of prior art capacitors. These effects may be substantially reduced or eliminated by application of the disclosed barriers.

[0165] Thus, the user is provided with an energy store housing 7 in which a substantial portion, up to all of the interior surfaces of the housing 7, is aluminum (and may include non-interfering materials as described below), thus avoiding problems of internal corrosion and providing the designer with greater flexibility in selecting a suitable material for the electrolyte 6.

[0166] By using a multi-layer material (e.g., a clad material), stainless steel may be incorporated into the housing 7, thus using components with a glass-to-metal seal. Components may be welded to the stainless steel side of the clad material using techniques such as laser or resistance welding, while the aluminum side of the clad material may be welded to other aluminum parts (e.g., body 20).

[0167] In some embodiments, an insulating polymer may be used to coat parts of the housing 7. In this way, it is possible to ensure that the energy storage components are only exposed to acceptable types of metals (such as aluminum). Exemplary insulating polymers include PFA, FEP, TFE, and PTFE. Suitable polymers (or other materials) are limited only by the needs of the system designer or manufacturer and the properties of the respective materials. See FIG. 23, where a small amount of insulating material 39 is included to limit exposure of the electrolyte 6 to the stainless steel of the sleeve 51 and the feedthrough 19. In this example, the terminal 8 is coupled to the feedthrough 19, such as by welding, and then coated with the insulating material 9.

[0168] Refer now to FIG. 24, where another embodiment aspect of the assembly of the cap 24 is depicted. FIG. 4A depicts a mold (or template) (i.e., blank 34) that is used to provide the body of the cap 24. The mold is generally sized to fit into the housing 7 of an appropriate type of energy storage cell (such as ultracapacitor 10). The cap 24 may be formed by first providing a mold forming die (as shown in FIG. 24B) that includes a dome 37 within the mold, and then drilling a through-way 32 in the dome 37 (as shown in FIG. 24C). Of course, the blank 34 (e.g., a circular metal stock) may be pressed or otherwise fabricated such that the above-mentioned features are simultaneously provided.

[0169] Generally, and for these embodiments, the cap may be formed from aluminum or an alloy thereof, although the cap may be formed from any material deemed appropriate by a manufacturer, user, designer, etc. For example, cap 24 may be made from steel and may be passivated (i.e., coated with an inert coating) or otherwise fabricated for use in housing 7.

[0170] 25, another embodiment of an electrode assembly 50 is shown. In these embodiments, the electrode assembly 50 includes a feedthrough 19 and a hemispherical shaped material disposed around the feedthrough 19. The hemispherical shaped material functions as an insulator 26 and is generally shaped to fit the dome 37. The hemispherical insulator 26 may be made of any material suitable for providing a seal while withstanding the chemical effects of the electrolyte 6. Exemplary materials include PFA (perfluoroalkoxy polymer), FEP (fluorinated ethylene propylene), PVF (polyvinyl fluoride), TFE (tetrafluoroethylene), CTFE (chlorotrifluoroethylene), PCTFE (polychlorotrifluoroethylene), ETFE (polyethylene tetrafluoroethylene), ECTFE (polyethylene chlorotrifluoroethylene), PTFE (polytetrafluoroethylene), other fluoropolymer-based materials, and any other material that may exhibit similar properties (to various degrees) and provide sufficient performance (e.g., by exhibiting high resistance to solvents, acids and bases, especially at high temperatures, low cost, etc.).

[0171] The feedthrough 19 may be formed from aluminum or an alloy thereof, although the feedthrough 19 may be formed from any material deemed appropriate by the manufacturer, user, designer, etc. For example, the feedthrough 19 may be made from steel and may be passivated (i.e., coated with an inert coating such as silicon) or otherwise prepared for use in the electrode assembly 50. An exemplary technique for passivation includes depositing a coating of hydrogenated amorphous silicon on the surface of the substrate and functionalizing the coated substrate by exposing the substrate to a binding reagent having at least one unsaturated hydrocarbon group under pressure and elevated temperature (or elevated temperature) for an effective length of time. The hydrogenated amorphous silicon coating is deposited by exposing the substrate to silicon hydride gas under pressure and elevated temperature (or elevated temperature) for an effective length of time.

[0172] The hemispherical insulator 26 may be sized relative to the dome 37 such that a snug fit (i.e., a tight seal) is achieved when installed within the cap 24. The hemispherical insulator 26 need not be perfectly symmetrical or of typical hemispherical proportions. That is, the hemispherical insulator 26 may be substantially hemispherical and may include, for example, slight adjustments in proportion, moderate flanges (at the base, etc.), and other features as deemed appropriate. Although the hemispherical insulator 26 is generally formed from a uniform material, this is not a requirement. For example, the hemispherical insulator 26 may include an air or gas filled torus (not shown) therein to provide the desired expansion or compression properties.

[0173] As shown in FIG. 26, the electrode assembly 50 may be inserted into a mold plate (ie, a molded blank 34) to provide one embodiment of a cap 24 that includes a hemispherical seal.

[0174] As shown in FIG. 27, in various embodiments, a retainer (or retainer) 43 may be coupled or otherwise fitted to the bottom of the cap 24 (i.e., the portion of the cap 24 that faces the interior of the housing 7 and faces the energy storage cells 12). The retainer 43 may be coupled to the cap 24 by various techniques, such as aluminum welding (e.g., laser, ultrasonic, etc.). Other techniques may be used for coupling, including, for example, stamping (i.e., mechanical coupling) and brazing. The coupling may be present, for example, along the circumference of the retainer 43. Generally, the coupling is provided at least at one coupling point to form the desired seal 71. At least one fastener, such as a plurality of rivets, may be used to seal the insulator 26 within the retainer 43.

[0175] In the example of Figure 27, the cap 24 is concave (see Figure 18B), although other shapes may be used. For example, a convex cap 24 may be provided (Figure 18C), or an over-cap 24 may be used (a variation of the embodiment of Figure 18C, configured to be attached as depicted in Figure 22C).

[0176] In some embodiments, at least one of the housing 7 and the cap 24 includes a material that includes multiple layers. For example, a first layer of material may include aluminum and a second layer of material may be stainless steel. In this example, the stainless steel is coated over the aluminum, resulting in a material that exhibits a desired combination of metallurgical properties. That is, in the embodiments presented herein, the aluminum is exposed to the interior of the energy storage cell (i.e., the housing), while the stainless steel is exposed to the exterior. In this way, the favorable electrical properties of the aluminum are obtained, while the structural properties (and metallurgical properties, i.e., weldability) of the stainless steel make the structure reliable. The multi-layer material may include additional layers as deemed appropriate. Advantageously, this provides for welding stainless steel to stainless steel, a relatively simple welding procedure.

[0177] The materials used for the cap and feedthrough 19 may be selected in relation to the thermal expansion of the hemispherical insulator 26. Additionally, manufacturing techniques may be devised to take the thermal expansion into account. For example, when assembling the cap 24, the manufacturer may apply pressure to the hemispherical insulator 26, thereby compressing it at least somewhat. In this way, at least some thermal expansion of the cap 24 may be accommodated therein without jeopardizing the effectiveness of the seal.

[0178] Materials used in the construction of body 20 include aluminum, although the designer or manufacturer may deem any type of aluminum or aluminum alloy (all of which are generally referred to herein simply as "aluminum") suitable. Various alloys, laminates, and the like may be disposed over (e.g., clad) the aluminum (which is exposed to the interior of body 20). Additional materials (such as structural or electrically insulating materials, some polymer-based materials, and the like) may be used to complement (or reinforce) the body and / or housing 7. Materials disposed over the aluminum may likewise be selected by whatever the designer or manufacturer deems appropriate.

[0179] The use of aluminum is not necessary or required. In short, the selection of materials may result in the use of any material that the designer, manufacturer, user, etc. deems appropriate. Various factors may be considered, such as reduced electrochemical interaction with the electrolyte 6, structural properties, cost, etc.

[0180] The storage cell 12 will now be discussed in more detail. See FIG. 28, where a cutaway view of the ultracapacitor 10 is presented. In this example, the storage cell 12 is inserted into and housed within the body 20. Each of the leads is bundled together and coupled to the housing 7 as one of the terminals 8. In some embodiments, the leads are coupled to the bottom of the body 20 (inside thereof), thereby making the body 20 the negative contact 55. Similarly, another set of leads is bundled and coupled to the feedthrough 19, thereby providing the positive contact 56. Electrical isolation of the negative and positive contacts 55 and 56 is maintained by the electrical insulator 26. Typically, the coupling of the leads is achieved by welding, such as laser and / or ultrasonic welding. Of course, other techniques may be used as deemed necessary.

[0181] It should be appreciated that to provide high performance energy storage, robust assembly techniques are required, and therefore, some assembly techniques are discussed herein.

[0182] 29, there is shown the components of one exemplary electrode 3. In this example, electrode 3 will be used as a negative electrode 3 (although this designation is arbitrary and for reference only).

[0183] As can be noted from the figure, at least in this embodiment, the separator 5 is generally longer and wider than the energy storage medium 1 (and current collector 2). The use of a larger separator 5 provides protection against shorting the negative and positive electrodes 3. The use of additional material in the separator 5 also provides better electrical protection for the leads and terminals 8.

[0184] Refer now to FIG. 30, which provides a side view of one embodiment of a storage cell 12. In this example, the stack of energy storage media 1 includes a first separator 5 and a second separator 5 such that the electrodes 3 are electrically separated when the storage cells 12 are assembled into a wound storage cell 23. Note that the terms "positive" and "negative" with respect to the assembly of the electrodes 3 and ultracapacitor 10 are merely arbitrary and refer to their functionality when configured in the ultracapacitor 10, in which a charge is stored. This convention, commonly adopted in the art, is not meant to apply to the charge being stored prior to assembly or to imply any other aspect other than providing a physical identification of the different electrodes.

[0185] Prior to winding the storage cell 12, the negative and positive electrodes 3 are aligned with respect to one another. When the highest degree of alignment is present, the path length for ion transport is generally minimal, so alignment of the electrodes 3 results in better performance of the ultracapacitor 10. Furthermore, by providing a high degree of alignment, excess separator 5 is not included, and as a result, the efficiency of the ultracapacitor 10 is not reduced.

[0186] 31, there is shown one embodiment of a storage cell 12 with electrodes 3 wound into a wound storage cell 23. One of the separators 5 is present as the outermost layer of the storage cell 12 and separates the energy storage medium 1 from the inside of the housing 7.

[0187] "Polarity matching" may be utilized to match the polarity of the outermost electrode in the wound storage cell 23 with the polarity of the body 20. For example, in some embodiments, the negative electrode 3 is on the outermost side of the tightly packed package that provides the wound storage cell 23. In these embodiments, another degree of assurance against short circuits is provided; that is, where the negative electrode 3 is coupled to the body 20, the negative electrode 3 is positioned as the outermost electrode in the wound storage cell 23. Thus, should the separator 5 fail, such as by mechanical wear induced by vibration of the ultracapacitor 10 during use, the ultracapacitor 10 will not fail as a result of a short between the outermost electrode in the wound storage cell 23 and the body 20.

[0188] For each embodiment of the wound storage cell 23, fiducial marks 72 may be present at least on the separator 5. The fiducial marks 72 may be used to effect placement of the leads on each of the electrodes 3. In some embodiments, the positioning of the leads is effected by calculation. For example, by taking into account the inner diameter of the jelly roll and the overall thickness of the combined separator 5 and electrodes 3, a location for placement of each lead may be estimated. Although, practice shows that using fiducial marks 72 is more efficient and effective. The fiducial marks 72 may include, for example, slits at the ends of the separator(s) 5.

[0189] Generally, the fiducial marks 72 are adopted for each new specification of the storage cell 12. That is, the specifications of the fiducial marks described above may be at least somewhat inaccurate, since the new specification of the storage cell 12 may require that the thickness of at least one layer within the cell be changed (from the embodiment described above).

[0190] Generally, the fiducial mark 72 is defined as a single radial line that traverses the roll from its center to its periphery. Thus, if leads were attached along the fiducial mark 72, each lead would be aligned with the remaining leads (as shown in FIG. 10). However, if the storage cell 12 is unwound (for embodiments in which the storage cell 12 is or will be a roll), the fiducial mark 72 may be considered to be multiple markings (as shown in FIG. 32). Conventionally, regardless of the embodiment or appearance of the markings on the storage cell 12, the identification of the location to incorporate the leads is considered to involve the determination of a "fiducial mark 72" or a "set of fiducial marks 72."

[0191] 32, once the fiducial marks 72 have been placed (such as by marking the rolled up storage cell 12), an attachment location (i.e., represented by the fiducial marks 72) is provided for attaching each of the leads. Once each attachment location has been identified, for any given assembly specification of the storage cell 12, the relative location of each attachment location may be repeated for additional instances of a particular assembly of the storage cell 12.

[0192] Typically, each lead is coupled to a respective current collector 2 in the storage cell 12. In some embodiments, both the current collector 2 and the leads are made of aluminum. Typically, the leads are coupled to the current collector 2 across a width W, although the leads may be coupled over only a portion of the width W. The coupling may be accomplished, for example, by ultrasonic welding of the leads to the current collector 2. To accomplish the coupling, at least some of the energy storage medium 1 may be removed (if necessary) so that each lead may be properly joined to the current collector 2. Other fabrication and conditioning may be performed as necessary to effect the coupling.

[0193] Of course, opposing fiducial marks 73 may be included. That is, in the same manner that fiducial marks 72 are provided, a set of opposing fiducial marks 73 may be created to accommodate attachment of leads for opposing polarities. That is, fiducial mark 72 may be used to attach a lead to a first electrode 3, such as the negative electrode 3, while opposing fiducial mark 73 may be used to attach a lead to the positive electrode 3. In embodiments in which the wound storage cell 23 is cylindrical, opposing fiducial marks 73 are located on opposite sides of the energy storage medium 1 and are offset vertically (or lengthwise) from fiducial marks 72 (as shown).

[0194] It should be noted that in FIG. 32, the fiducial mark 72 and the opposing fiducial mark 73 are both shown to be located on one electrode 3. That is, FIG. 29 depicts an embodiment that is merely for the purpose of illustrating the spatial (i.e., linear) relationship of the fiducial mark 72 and the opposing fiducial mark 73. This is not meant to imply that the positive electrode 3 and the negative electrode 3 share the energy storage medium 1. It should be noted, however, that in an example in which the fiducial mark 72 and the opposing fiducial mark 73 are provided by rolling up the storage cell 12 and then marking the separator 5, the fiducial mark 72 and the opposing fiducial mark 73 may actually be present by being provided on one separator 5. However, in practice, only one set of the fiducial mark 72 and the opposing fiducial mark 73 would be used to attach leads to any given electrode 3. That is, it should be understood that the embodiment depicted in FIG. 32 should be complemented with another layer of the energy storage medium 1 for another electrode 3 that would have the opposite polarity.

[0195] As shown in Figure 33, the above-described assembly technique results in a storage cell 12 that includes at least one set of aligned leads. A first set of aligned leads 91 are particularly useful in coupling the wound storage cell 23 with one of the negative and positive contacts 55, 56, while an opposing set of aligned leads 92 provides coupling between the energy storage medium 1 and the opposing contacts (55, 56).

[0196] The rolled storage cell 23 may be surrounded by a packaging member 93. The packaging member 93 may be realized in various embodiments. For example, the packaging member 93 may be provided as KAPTON™ tape (a polyimide film developed by DuPont, Wilmington, Del.) or PTFE tape. In this example, the KAPTON™ tape surrounds and is adhered to the rolled storage cell 23. The packaging member 93 may be provided without adhesion, such as a form-fitting packaging member 93 that slides over the rolled storage cell 23. The packaging member 93 may be further manifested as a bag, such as a bag (e.g., envelope 73 discussed above) that encases the rolled storage cell 23 in its majority. In some of these embodiments, the packaging member 93 may include a material that functions as a shrink wrap, thereby providing efficient physical (and in some embodiments chemical) containment of the rolled storage cell 23. In general, the packaging member 93 is formed from a material that does not interfere with the electrochemical function of the ultracapacitor 10. The packaging member 93 may provide some covering if desired, for example to aid in the insertion of the rolled storage cell 23 .

[0197] In some embodiments, the negative and positive leads are located on opposite sides of the wound storage cell 23 (for a jelly-roll type wound storage cell 23, the leads for the negative and positive polarities may be diametrically opposed). Generally, locating the leads for the negative and positive polarities on opposite sides of the wound storage cell 23 was done to facilitate manufacturing of the wound storage cell 23 and to provide improved electrical isolation.

[0198] In some embodiments, once the arrayed leads 91, 92 are assembled, each of the multiple arrayed leads 91, 92 are bundled together (at appropriate locations) such that a shrink wrap (not shown) can be placed around the multiple arrayed leads 91, 92. Typically, the shrink wrap is formed from PTFE, although any suitable material may be used.

[0199] In some embodiments, once the shrink wrap material is placed around the aligned leads 91, the aligned leads 91 are bent (or folded) into the shape they are to assume when the ultracapacitor 10 is assembled. That is, with reference to FIG. 34, it may be understood that the aligned leads assume a "Z" shape. After imparting the "Z fold" to the aligned leads 91, 92 and applying the shrink wrap, the shrink wrap may be heated or otherwise activated such that it shrinks into position around the aligned leads 91, 92. Thus, in some embodiments, the aligned leads 91, 92 may be reinforced and protected by the packaging material. The use of a Z fold is particularly useful when coupling the energy storage medium 1 to a feedthrough 19 that is disposed within the cap 24.

[0200] Of course, other embodiments may be implemented for coupling each set of arranged leads 91, 92 (i.e., each terminal 8) to the respective contacts 55, 56. For example, in one embodiment, an intermediate lead is coupled to one of the feedthrough 19 and the housing 7 to facilitate coupling to each set of arranged leads 91, 92.

[0201] The materials used may be selected according to properties such as reactivity, dielectric value, melting point, adhesion to other materials, weldability, coefficient of friction, cost, and other such factors. Combinations of materials (such as laminated, mixed, or otherwise combined) may be used to provide desired properties.

[0202] In various embodiments, multiple ultracapacitors 10 are useful for use together to provide a power supply. To provide reliable operation, individual ultracapacitors 10 may be tested prior to use. To perform various types of tests, each ultracapacitor 10 may be tested as a cell connected in series or parallel with multiple attached ultracapacitors 10. By using different metals joined by various techniques (such as welding), the ESR of the connection can be reduced and the strength of the connection can be increased. Some aspects of the connections between ultracapacitors 10 are now introduced.

[0203] In some embodiments, the ultracapacitor 10 includes two contacts: a glass-to-metal seal pin (i.e., feedthrough 19) and the entire rest of the housing 7. When connecting multiple ultracapacitors 10 in series, it is often desirable to connect the interconnect between the bottoms of the housings 7 (in the case of cylindrical housings 7) so that the distance to the internal leads is minimal, and therefore the least resistance. In these embodiments, the opposing ends of the interconnect are typically connected to the glass-to-metal seal pin.

[0204] For the interconnects, a common type of welding involves using a side-by-side tip electric resistance welder. The welding may be done by aligning the end of the interconnect over the pin and welding the interconnect directly to the pin. Using multiple welds will increase the strength and connection between the interconnect and the pin. In general, when welding to the pin, configuring the shape of the end of the interconnect to fit closely with the pin helps ensure that there is substantially no excess material overlapping the pin that would cause a short circuit.

[0205] An opposing tip electrical resistance welder may be used to weld the interconnects to the pins, while an ultrasonic welder may be used to weld the interconnects to the bottom of the housing 7. Soldering techniques may be used where the metals involved are compatible.

[0206] Regarding materials used for the interconnects, a common type of material used for the interconnects is nickel. Nickel may be used because it welds well with stainless steel and has a strong interface. Other metals and alloys may be used in place of nickel, for example to reduce resistance in the interconnects.

[0207] Generally, the material selected for the interconnects is selected for compatibility with the materials in the pins and in the housing 7. Exemplary materials include copper, nickel, tantalum, aluminum, and nickel-copper clad. Additional metals that may be used include silver, gold, brass, platinum, and tin.

[0208] In some embodiments, such as those in which the pins (i.e., feedthroughs 19) are made from tantalum, the interconnect may utilize an intermediate metal, such as by employing a short bridge connection. An exemplary bridge connection includes a strip of tantalum that is modified by using an opposing tip resistance welder to weld an aluminum / copper / nickel strip into the bridge. A parallel resistance welder is then used to weld the tantalum strip to the tantalum pin.

[0209] A bridge may be used at the contact which is the housing 7. For example, a nickel strip may be resistance welded to the bottom of the housing 7. A copper strip may then be ultrasonically welded to the nickel bridge. This technique helps to lower the resistance of the cell interconnects. By using different metals for each connection, the ESR of the interconnect between directly connected cells can be reduced.

[0210] Having thus described aspects of a robust ultracapacitor 10 useful for high temperature environments (ie, up to about 210° C.), several additional aspects are now presented and / or defined.

[0211] A variety of materials may be used in the construction of ultracapacitor 10. The integrity of ultracapacitor 10 is essential where oxygen and moisture are to be excluded and electrolyte 6 is to be prevented from leaking. To accomplish this, the seam welds and any other sealing points should meet criteria for hermeticity over the intended temperature range for operation. The materials selected should also be compatible with other materials such as ionic liquids and solvents that may be used in the formulation of electrolyte 6.

[0212] In some embodiments, the feedthrough 19 is formed from a metal such as at least one of KOVAR™ (a trademark of Carpenter Technology Corporation, Reading, Pennsylvania. KOVAR is a vacuum melted iron-nickel-cobalt low expansion alloy whose chemical composition is controlled within a narrow range that ensures precise and uniform thermal expansion characteristics), Alloy 52 (a nickel-iron alloy suitable for glass and ceramic sealing to metal), tantalum, molybdenum, niobium, tungsten, Stainless Steel 446 (a ferritic, non-heat treatable (??) stainless steel that exhibits good resistance to high temperature corrosion and oxidation), and titanium.

[0213] The body (or main body) of a glass-to-metal seal utilizing the above may be manufactured from 300 series stainless steels such as 304, 304L, 316 and 316L alloys. The body may also be made from metals such as at least one of various nickel alloys such as Inconel (a family of austenitic nickel-chromium based superalloys that are oxidation and corrosion resistant materials well suited for installations in extreme environments subjected to pressure and heat) and Hastelloy (a highly corrosion resistant metal alloy containing nickel and various percentages (or proportions) of molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon and tungsten).

[0214] The insulating material between the feedthrough 19 and the surrounding body in a glass-to-metal seal is usually glass, the composition of which is proprietary to each manufacturer of the seal and depends on whether the seal is under compression or conformal. Other insulating materials may be used in glass-to-metal seals. For example, various polymers may be used in the seal. The term "glass-to-metal" seal, by itself, is merely descriptive of the type of seal and is not meant to imply that the seal must contain glass.

[0215] The housings 7 of the ultracapacitors 10 may be made from stainless steel, for example types 304, 304L, 316 and 316L. They may also be constructed from a number of aluminum alloys, including, but not limited to, 1100, 3003, 5052, 4043 and 6061. A variety of multi-layer materials may be used, including, for example, stainless steel clad aluminum. Other non-limiting compatible metals that may be used include platinum, gold, rhodium, ruthenium and silver.

[0216] Specific examples of glass-to-metal seals that have been used in ultracapacitor 10 include two different types of glass-to-metal seals. A first glass-to-metal seal is provided by SCHOTT, with US locations in Elmsford, NY. This embodiment uses a stainless steel pin, a glass insulator, and a stainless steel body. A second glass-to-metal seal is provided by HERMETIC SEAL TECHNOLOGY, Cincinnati, OH. This second embodiment uses a tantalum pin, a glass insulator, and a stainless steel body. Various dimensions of the various embodiments may be provided. Various dimensions of the various embodiments may be provided.

[0217] Additional embodiments of glass-to-metal seals include those that use aluminum seals and aluminum bodies. Yet another embodiment of a glass-to-metal seal includes an aluminum seal with epoxy or other insulating material (such as ceramic or silicone).

[0218] Many aspects of the glass-to-metal seal may be constructed as desired. For example, the dimensions of the housing and pins, as well as the materials of the pins and housing may be varied as needed. The pins may be tubular or solid pins, and it is possible to have multiple pins in one cover. The most common types of materials used for the pins are stainless steel alloys, copper cored stainless steel, molybdenum, platinum-iridium, various nickel-iron alloys, tantalum, and other metals, although some non-transitional materials (such as aluminum) may be used. The housing is typically formed from stainless steel, titanium, and / or various other materials.

[0219] Various fastening techniques may be used in the assembly of ultracapacitor 10. For example, and with respect to welding, various welding techniques may be used. Below is an illustrative list of the types of welds and the various purposes for which each type of weld may be used.

[0220] Ultrasonic welding may be used, among other things, to weld the aluminum tabs to the current collector; to weld the tabs to the bottom jacket cover; to weld the jumper (or jumper wire) tabs to the jacket bridge that connects to the glass-to-metal seal pin; and to weld the jelly roll tabs together. Pulse or resistance welding may be used, among other things, to weld the leads to the can bottom or pin; to weld the leads to the current collector; to weld the jumper to the jacket bridge; to weld the jacket bridge to the terminal 8; and to weld the leads to the bottom cover. Laser welding may be used, among other things, to weld the stainless steel cover to the stainless steel can; to weld the stainless steel bridge to the stainless steel glass-to-metal seal pin; and to weld the plug into the filler spout. TIG welding may be used, among other things, to seal the aluminum cover to the aluminum can; and to weld the aluminum seal in place. Cold welding (or cold pressure welding) (compressing metal together with great force) may be used, among other things, to seal the inlet by press-fitting an aluminum ball / clasp into the inlet.

[0221] The physical aspects of an exemplary ultracapacitor 10 are now presented. Note that in the table below, the term "tab" generally refers to the "lead" discussed above; the terms "bridge" and "jumper" also refer to aspects of the lead (e.g., a bridge may be coupled to a feedthrough or "pin," while a jumper is useful for connecting a bridge to a tab or lead). Using various connections may facilitate the assembly process and may utilize certain assembly techniques. For example, a bridge may be laser or resistance welded to a pin, or welded to a jumper by ultrasonic welding.

[0222] [Table 7]

[0223] [Table 8]

[0224] [Table 9]

[0225] [Table 10]

[0226] As a verification of purity in the ultracapacitor 10, the sealed ultracapacitor 10 housing 7 was opened and the storage cell 12 was sampled for impurities. The electrodes, separator, and electrolyte from the cell 12 were measured for water content using the Karl Fischer method. Measurements were made in triplicate and averaged.

[0227] The water content (i.e., moisture level) of the electrodes and separator were found to be 343.3 ppm (per weight percent) and 152.6 ppm (per weight percent), respectively. To measure the water content in electrolyte 6, 1.1 ml of electrolyte from the closed cell was mixed with 4 ml of purified electrolyte. The water content of the mixture was then measured. Knowing the water content in the added electrolyte (60.3 ppm), the water content of the electrolyte removed from the cell was determined. Thus, the water content of electrolyte 6 in the sealed ultracapacitor 10 was 15.5 ppm. The halide content in the ultracapacitor 10 was measured using an ion selective electrode (ISE). The average chloride (Cl - ) ion content was found to be 90.9 ppm in electrolyte 6, while the average fluoride (F - ) content was found to be 0.25 ppm.

[0228] In general, a method for characterizing contaminants in an ultracapacitor involves disrupting the housing 7 to access its contents, sampling the contents, and analyzing the samples. Techniques disclosed elsewhere herein may be used to assist in the characterization.

[0229] To ensure accurate measurement of impurities in the ultracapacitor and its components (including the electrodes, electrolyte and separator), assembly and disassembly may be performed in a suitable environment, such as an inert environment in a glove box.

[0230] Figures 35-38 are graphs illustrating the performance of an exemplary ultracapacitor 10. Figures 35 and 36 illustrate the performance of ultracapacitor 10 at 1.75 volts and 125°C. Figures 37 and 38 illustrate the performance of ultracapacitor 10 at 1.5 volts and 150°C.

[0231] In general, ultracapacitor 10 may be used under a variety of environmental conditions and requirements. For example, the terminal voltage may range from about 100 mV to 10 V. The ambient temperature may range from about -40°C to +210°C. A typical hot ambient temperature is in the range of +60°C to +210°C.

[0232] 39-43 are additional graphs illustrating the performance of an exemplary ultracapacitor 10. In these examples, the ultracapacitor 10 was a closed cell (i.e., housing). The ultracapacitor was cycled 10 times at 100 mA charge / discharge by charging to 0.5 volts, measuring the resistance, discharging to 10 mV, resting for 10 seconds, and then cycling again.

[0233] Tables 11 and 12 present comparative performance data for embodiments of ultracapacitor 10. Performance data was collected for various operating conditions as indicated.

[0234] [Table 11]

[0235] [Table 12]

[0236] Thus, the data presented in Tables 11 and 12 demonstrate that the teachings herein enable operation of ultracapacitors in extreme conditions. Ultracapacitors so manufactured may, for example, exhibit a leakage current of less than about 1 mA per milliliter of cell volume (while held at a voltage of less than about 2 V and a temperature of less than about 150° C.) and an ESR increase of less than about 100 percent in 500 hours. As tradeoffs are made between the various requirements of the ultracapacitor (e.g., voltage and temperature), the performance rating of the ultracapacitor may be controlled (e.g., capacitance, rate of increase in ESR) and adjusted to accommodate specific needs. In connection with the above, it is noted that "performance rating" is given by a commonly used definition that relates to values ​​for parameters that describe the state of operation.

[0237] It should be noted that the capacitance and ESR measurements presented in Table 11 and elsewhere herein follow commonly known methods. First, consider the technique for measuring capacitance.

[0238] Capacitance may be measured in a number of ways. One method involves monitoring the voltage presented at the capacitor terminals while a known current is drawn from (during "discharging") and supplied to (during "charging") the ultracapacitor. More specifically, one may use the fact that an ideal capacitor is governed by the following equation: I=C*dV / dt where I represents the charging current, C represents the capacitance, and dV / dt represents the time derivative of the ideal capacitor voltage V. An ideal capacitor is, among other things, one that has zero internal resistance and whose capacitance is independent of voltage. If the charging current I is constant, the voltage V is linear (or straight line) with respect to time, and therefore dV / dt may be calculated as the slope of that line or as ΔV / ΔT. However, this method is generally an approximation, and the voltage difference caused by the equivalent series resistance (ESR drop) of the capacitor should be considered in the capacitance calculation or measurement. The equivalent series resistance (ESR) may generally be a lumped element approximation of dissipative or other effects in a capacitor. Capacitor behavior is often derived from a circuit model that includes an ideal capacitor in series with a resistor with a resistance equal to the ESR. In general, this gives a good approximation of the behavior of a real capacitor.

[0239] In one method of measuring capacitance, if the internal resistance is substantially independent of voltage and the charge or discharge current is substantially fixed, the effect of the ESR drop may be largely ignored. In that case, the ESR drop may be approximated as constant and is necessarily subtracted from the calculation of the voltage change during constant current charging or discharging as described above. As a result, the change in voltage is substantially a reflection of the change in charge stored in the capacitor. Thus, the change in voltage may be taken, by calculation, as an indication of capacitance.

[0240] For example, during a constant current discharge, a constant current I is known. By measuring the change in voltage ΔV during discharge, over a measurement time interval ΔT, and dividing the current value I by the ratio ΔV / ΔT, an approximation (or estimate) of capacitance is obtained. If I is measured in amperes, ΔV in volts, and ΔT in seconds, the resulting capacitance will be in farads.

[0241] When considering an estimate of ESR, the equivalent series resistance (ESR) of an ultracapacitor may be measured in a number of ways. One method involves monitoring the voltage seen at the capacitor terminals while a known current is drawn from (during "discharging") or supplied to (during "charging") the ultracapacitor. More specifically, one may use the fact that ESR is governed by the following equation: V=I*R where I effectively represents the current through the ESR, R represents the resistance of the ESR, and V represents the voltage difference caused by the ESR (ESR drop). The ESR may generally be a lumped element approximation of dissipative or other effects in an ultracapacitor. Ultracapacitor behavior is often calculated from a circuit model that includes an ideal capacitor in series with a resistor that has a resistance equal to the ESR. This generally provides a good approximation of the behavior of a real capacitor.

[0242] In one method of measuring ESR, one may begin drawing a discharge current from a capacitor that has been at rest (a capacitor that has not been charged or discharged with a substantial current). During the time interval during which the change in voltage seen by the capacitor due to a change in the charge stored in the capacitor is small compared to the measured voltage change, the measured voltage change is substantially a reflection of the ESR of the capacitor. Under these conditions, the instantaneous voltage change seen by the capacitor may be taken, by calculation, as an indication of the ESR.

[0243] For example, when a discharge current is initiated to flow from a capacitor, an instantaneous voltage change ΔV may be noted over a measurement interval ΔT. To the extent that the capacitance C of a capacitor being discharged by a known current I during the measurement interval ΔT is small compared to the measured voltage change ΔV, ΔV during that time interval ΔT may be divided by the discharge current I to obtain an approximation of the ESR. If I is measured in amperes and ΔV is measured in volts, the ESR result will have units of Ωs.

[0244] Both ESR and capacitance may be dependent on ambient temperature, and therefore, relevant measurements may require the user to subject ultracapacitor 10 to a particular ambient temperature of interest during the measurements.

[0245] The leakage current performance requirements are generally dictated by the environmental conditions prevailing in a particular application. For example, for a capacitor with a volume of 20 mL, a practical limit for leakage current may be below 100 mA. As referred to herein, the "volumetric leakage current" of ultracapacitor 10 generally refers to the leakage current divided by the volume of ultracapacitor 10, and may be expressed, for example, in units of mA / cc. Similarly, the "volumetric capacitance" of ultracapacitor 10 generally refers to the capacitance of ultracapacitor 10 divided by the volume of ultracapacitor 10, and may be expressed, for example, in units of F / cc. Additionally, the "volumetric ESR" of ultracapacitor 10 generally refers to the ESR of ultracapacitor 10 multiplied by the volume of ultracapacitor 10, and may be expressed, for example, in units of Ωs·cc.

[0246] It should be noted that one way to reduce the volumetric leakage current at a particular temperature is to reduce the operating voltage at that temperature. Another way to reduce the volumetric leakage current at a particular temperature is to increase the volume of the voids in the ultracapacitor. Yet another way to reduce the leakage current is to reduce the loading of the energy storage medium 1 in the electrodes 3.

[0247] There may be a variety of environments in which ultracapacitor 10 is particularly useful. For example, in automotive applications, ambient temperatures of 105° C. may be realized (where the useful life of the capacitor may range from about 1 year to 20 years). In some downhole applications, such as for drilling geothermal wells, ambient temperatures of 300° C. or higher may be achieved (where the useful life of the capacitor may range from about 100 hours to 10,000 hours).

[0248] The "life" of a capacitor is also generally defined by the particular application and is usually indicated by a certain percentage increase in leakage current or a decrease in another parameter (as appropriate or determinative for a given application). For example, in one embodiment, the life of a capacitor in an automotive application may be defined as the time at which the leakage current has increased to 200% of its initial (beginning of life or "BOL") value.

[0249] The electrolyte 6 may be selected to exhibit desired properties such as high thermal stability, low glass transition temperature (Tg), viscosity, specific rhoepectic or thixotropic properties (e.g., temperature dependent), as well as high conductivity and good electrical performance over a wide range of temperatures. By way of example, the electrolyte 6 may have a high degree of fluidicity to ensure separation of the electrodes 3, or, in contrast, may be substantially solid. Thus, other embodiments of the electrolyte 6 exhibiting desired properties may be used as well, or may be used in conjunction with any of the above.

[0250] "Peak power density" is 1 / 4 times the square of the peak device voltage divided by the equivalent series resistance of the device. "Energy density" is 1 / 2 times the square of the peak device voltage multiplied by the capacitance of the device.

[0251] For purposes of the present invention, ultracapacitor 10 may have a volume ranging from about 0.05 cc to about 7.5 liters.

[0252] A nominal value of a normalized parameter may be obtained by multiplying the normalized parameter (e.g., volumetric leakage current) by a normalization exponent (e.g., volume) or dividing the normalized parameter (e.g., volumetric leakage current) by a normalization exponent (e.g., volume). For example, an ultracapacitor with a volumetric leakage current of 10 mA / cc and a volume of 50 cc has a nominal leakage current of the volumetric leakage current times the volume, which is 500 mA. Meanwhile, an ultracapacitor with a volumetric ESR of 20 mΩ·cc and a volume of 50 cc has a nominal ESR of the volumetric ESR and the volume, which is the quotient of 0.4 mΩ.

[0253] The volume of a particular ultracapacitor 10 may be expanded by combining several storage cells in one housing such that they are electrically in parallel or in series (eg, welding several jelly rolls together).

[0254] An embodiment of ultracapacitor 10 exhibiting a relatively small volume may be fabricated in a prismatic form factor such that the electrodes 3 of ultracapacitor 10 face each other, with at least one electrode 3 having an internal contact to a glass-to-metal seal and the other electrode 3 having an internal contact to a housing or glass-to-metal seal.

[0255] It should be understood that the teachings herein are for illustrative purposes only and are not limiting of the present invention. Moreover, one skilled in the art will appreciate that additional components, configurations, arrangements, etc. may be implemented while remaining within the scope of the present invention. For example, the configurations of layers, electrodes, leads, terminals, contacts, feedthroughs, caps, etc. may vary from the embodiments disclosed herein. In general, the design and / or application of components of an ultracapacitor(s) that utilize electrodes is limited only by the needs of the system designer, manufacturer, operator and / or user and the requirements presented in any particular situation.

[0256] Moreover, various other components may be included as desired to provide aspects of the teachings herein. For example, additional materials, combinations of materials, and / or omissions of materials may be used to provide added embodiments that are within the scope of the teachings herein, and terms such as "compatible with," "constitute," "construct," and the like may be considered to include the application of any of the techniques disclosed herein and other similar techniques (which may be currently known or may later be devised) to produce an intended result.

[0257] When introducing elements (or components) of the invention or embodiment(s) of the invention, the articles "a," "an," and "the" are intended to mean that there is one or more elements (or components). Similarly, the adjective "another," when used to introduce an element (or component), is intended to mean one or more elements (or components). The terms "comprise," "have," and "contain" are intended to be inclusive such that there may be additional elements other than the listed elements.

[0258] In this application, various variables are described, including but not limited to components (e.g., electrode materials, electrolytes, etc.), conditions (e.g., temperature, absence of various impurities at various levels), and performance characteristics (e.g., post-cycle capacity compared to initial capacity, low leakage current, etc.). It should be understood that any combination of any of these variables can define an embodiment of the invention. For example, a combination of a specific electrode material and a specific electrolyte operated under a specific temperature, with less than a specific amount of impurities, and with a specific value of post-cycle capacity and leakage current (these variables are included as possibilities, but the specific combination is not explicitly presented) is one embodiment of the invention. As will be apparent to one of ordinary skill in the art, articles, components, conditions, and / or methods can also be specifically selected from the variables listed herein to define other embodiments.

[0259] It will be appreciated that various components or techniques may provide certain necessary or useful functionality or features, and thus, these functions and features are understood to be inherently included as part of the teachings herein and as part of the disclosed invention, as may be required as support for the appended claims and variations thereof.

[0260] Although the invention has been described with reference to exemplary embodiments, it will be understood that various modifications may be made without departing from the scope of the invention, and that elements of the invention may be substituted with equivalents. In addition, many modifications will be understood to adapt a particular equipment, situation or material to the teachings of the invention without departing from the essential scope of the invention. It is therefore intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but should be construed in accordance with the scope of the claims appended hereto.

Claims

1. 1. An ultracapacitor including an energy storage cell and an electrolyte within a sealed housing, the cell being electrically coupled to a positive contact and a negative contact, the ultracapacitor configured to operate at a temperature within a temperature range of approximately 80°C to 210°C.

2. 10. The ultracapacitor of claim 1, wherein the temperature range is from about 90°C to about 210°C.

3. 10. The ultracapacitor of claim 1, wherein the temperature range is from about 80°C to about 150°C.

4. The ultracapacitor of claim 1 , wherein the ultracapacitor is operable in a sub-range within said temperature range, the sub-range being approximately 10° C.

5. 10. The ultracapacitor of claim 1, wherein the energy storage cell comprises a positive electrode and a negative electrode.

6. The ultracapacitor of claim 5 , wherein at least one of the electrodes comprises a carbonaceous energy storage medium.

7. The ultracapacitor of claim 6 , wherein the carbonaceous energy storage medium comprises carbon nanotubes.

8. 7. The ultracapacitor of claim 6, wherein the carbonaceous energy storage medium comprises at least one of a plurality of forms of activated carbon, carbon fiber, rayon, graphene, aerogel, carbon cloth, and carbon nanotubes.

9. The ultracapacitor of claim 5 , wherein each electrode includes a current collector.

10. 10. The ultracapacitor of claim 1, wherein the electrolyte is purified to reduce impurity content.

11. 10. The ultracapacitor of claim 1, wherein the electrolyte contains less than about 1000 ppm of halide ions.

12. 10. The ultracapacitor of claim 1, wherein the electrolyte contains less than about 500 ppm of halide ions.

13. 10. The ultracapacitor of claim 1, wherein the electrolyte contains less than about 100 ppm of halide ions.

14. 10. The ultracapacitor of claim 1, wherein the electrolyte contains less than about 50 ppm of halide ions.

15. 12. The ultracapacitor of claim 11, wherein the halide ions include at least one of chloride, bromide, fluoride, and iodide.

16. 10. The ultracapacitor of claim 1, wherein the total concentration of metal species in the electrolyte is less than about 1000 ppm.

17. 17. The ultracapacitor of claim 16, wherein the metal species comprises at least one of Br, Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb, Zn, an alloy of any of the foregoing, and an oxide of any of the foregoing.

18. 10. The ultracapacitor of claim 1, wherein the total level of impurities in the electrolyte is less than about 1000 ppm.

19. 20. The ultracapacitor of claim 18, wherein the impurities include at least one of bromoethane, chloroethane, 1-bromobutane, 1-chlorobutane, 1-methylimidazole, ethyl acetate, and methylene chloride.

20. 10. The ultracapacitor of claim 1, wherein the total water content in the electrolyte is less than about 500 ppm.

21. 10. The ultracapacitor of claim 1, wherein the total water content in the electrolyte is less than about 100 ppm.

22. 10. The ultracapacitor of claim 1, wherein the total water content in the electrolyte is less than about 50 ppm.

23. 10. The ultracapacitor of claim 1, wherein the total water content in the electrolyte is about 20 ppm.

24. 2. The ultracapacitor of claim 1, wherein the cation of the electrolyte is selected from the group including 1-(3-cyanopropyl)-3-methylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1,3-bis(3-cyanopropyl)imidazolium, 1,3-diethoxyimidazolium, 1-butyl-1-methylpiperidinium, 1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium, 1-butyl-4-methylpyridinium, 1-butylpyridinium, 1-decyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, and 3-methyl-1-propylpyridinium.

25. 10. The ultracapacitor of claim 1, wherein the cation of the electrolyte is selected from the group including ammonium, imidazolium, oxazolium, phosphonium, piperidinium, pyrazinium, pyrazinium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, sulfonium, thiazolium, triazolium, guanidium, isoquinolinium, benzotriazolium, viologen-type and functional imidazolium cations.

26. At least one branched group (R ｘ 26. The ultracapacitor of claim 25, wherein: R is selected from the group consisting of alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano, hydroxyl, sulfate, sulfonate, and carbonyl groups.

27. 27. The ultracapacitor of claim 26, wherein the alkyl is selected from the group including saturated aliphatic groups, straight chain alkyl groups, branched chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups.

28. 27. The ultracapacitor of claim 26, wherein the alkyl is selected from the group including methyl, ethyl, propyl, butyl, pentyl, hexyl, ethylhexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

29. 27. The ultracapacitor of claim 26, wherein the heteroalkyl comprises an alkyl group that includes at least one heteroatom.

30. 30. The ultracapacitor of claim 29, wherein the heteroatoms are selected from the group including oxygen, nitrogen, and sulfur.

31. 27. The ultracapacitor of claim 26, wherein the alkyl and alkynyl groups comprise aliphatic groups.

32. 27. The ultracapacitor of claim 26, wherein the aliphatic group includes at least one of a double bond and a triple bond.

33. The anion of the electrolyte is -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － 10. The ultracapacitor of claim 1, selected from the group comprising:

34. The anion of the electrolyte is A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl group, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

35. The ultracapacitor of claim 1 , wherein the anion of the electrolyte comprises a substructure bonded with a respective number of substituents.

36. 36. The ultracapacitor of claim 35, wherein the base structure comprises one of N, O, CO, SO, Be, C, Mg, Ca, Ba, Ra, Au, B, Al, Ga, Th, In, P, S, Sb, As, N, Bi, Nb, and Sb.

37. 36. The ultracapacitor of claim 35, wherein each number of substituents is at least two.

38. 38. The ultracapacitor of claim 37, wherein the substituents are one of diverse and repetitive.

39. The anion of the electrolyte is a basic structure (Y ２ ) and two substituents (α ２ 10. The ultracapacitor of claim 1 ,

40. The anion of the electrolyte is the basic structure (Y ２ ) and two substituents (α ２ ), and the base structure (Y ２ ) is selected from the group consisting of N, O, CO and SO, and has two substituents (α ２ ) each represents -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － and A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl group, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

41. The anion of the electrolyte is a basic structure (Y ３ ) and three substituents (α ３ 10. The ultracapacitor of claim 1 ,

42. The anion of the electrolyte is the basic structure (Y ３ ) and three substituents (α ３ ), and the base structure (Y ３ ) is selected from the group consisting of Be, C, N, O, Mg, Ca, Ba, Ra, and Au, and has three substituents (α ３ ) each represents -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － and A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl group, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

43. The anion of the electrolyte is a basic structure (Y ４ ) and four substituents (α ４ 10. The ultracapacitor of claim 1 ,

44. The anion of the electrolyte is the basic structure (Y ４ ) and four substituents (α ４ ), and the base structure (Y ４ ) is selected from the group consisting of B, Al, Ga, Th, In, and P, and has four substituents (α ４ ) each represents -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － and A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl group, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

45. The anion of the electrolyte is a basic structure (Y ６ ) and six substituents (α ６ 10. The ultracapacitor of claim 1 ,

46. The anion of the electrolyte is the basic structure (Y ６ ) and six substituents (α ６ ), and the base structure (Y ６ ) is selected from the group consisting of P, S, Sb, As, N, Bi, Nb, Sb, and six substituents (α ６ ) each represents -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － and A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl group, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

47. The ultracapacitor of claim 1 , wherein the electrolyte comprises a solvent.

48. 48. The ultracapacitor of claim 47, wherein the solvent comprises at least one of acetonitrile, amides, benzonitrile, butyrolactone, cyclic ethers, dibutyl carbonate, diethyl carbonate, diethyl ether, dimethoxyethane, dimethyl carbonate, dimethylformamide, dimethylsulfone, dioxane, dioxolane, ethyl formate, ethylene carbonate, ethyl methyl carbonate, lactones, linear ethers, methyl formate, methyl propionate, methyl tetrahydrofuran, nitriles, nitrobenzene, nitromethane, n-methylpyrrolidone, propylene carbonate, sulfolane, sulfones, tetrahydrofuran, tetramethylene sulfone, thiophene, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, carbonate esters, gamma-butyrolactone, nitriles, and tricyanohexane.

49. The ultracapacitor of claim 1 , wherein the housing includes a barrier disposed over a substantial portion of its interior surface.

50. 50. The ultracapacitor of claim 49, wherein the barrier comprises at least one of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE).

51. 50. The ultracapacitor of claim 49, wherein the barrier comprises a ceramic material.

52. 50. The ultracapacitor of claim 49, wherein the barrier comprises a material that exhibits corrosion resistance, desirable dielectric properties, and low electrochemical reactivity.

53. 50. The ultracapacitor of claim 49, wherein the barrier comprises multiple layers of material.

54. The ultracapacitor of claim 1 , wherein the housing comprises a multi-layer material.

55. 55. The ultracapacitor of claim 54, wherein the multi-layer material comprises a first material coated on a second material.

56. 55. The ultracapacitor of claim 54, wherein the multi-layer material comprises at least one of steel, tantalum, and aluminum.

57. The ultracapacitor of claim 1 , wherein the housing includes at least one hemispherical seal.

58. The ultracapacitor of claim 1 , wherein the housing includes at least one glass-to-metal seal.

59. 60. The ultracapacitor of claim 58, wherein a pin of the glass-to-metal seal provides one of the contacts.

60. 60. The ultracapacitor of claim 58, wherein the glass-to-metal seal comprises a feedthrough comprising one of an iron-nickel-cobalt alloy, a nickel-iron alloy, tantalum, molybdenum, niobium, tungsten, a form of stainless steel, and titanium.

61. 60. The ultracapacitor of claim 58, wherein the glass-to-metal seal comprises a body comprising at least one of nickel, molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon, and tungsten and alloys thereof.

62. 10. The ultracapacitor of claim 1, wherein the energy storage cell includes a separator that provides electrical isolation between the positive and negative electrodes.

63. The separator is made of polyamide, polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), aluminum oxide (Al ２ O ３ ), fiberglass and fiberglass reinforced plastic.

64. 64. The ultracapacitor of claim 63, wherein the separator is substantially free of moisture.

65. 64. The ultracapacitor of claim 63, wherein the separator is substantially hydrophobic.

66. The airtight seal is approximately 5.0 x 10 －６ 10. The ultracapacitor of claim 1, exhibiting a leakage rate of atm-cc / sec or less.

67. The airtight seal is approximately 5.0 x 10 －７ 10. The ultracapacitor of claim 1, exhibiting a leakage rate of atm-cc / sec or less.

68. The airtight seal is approximately 5.0 x 10 －８ 10. The ultracapacitor of claim 1, exhibiting a leakage rate of atm-cc / sec or less.

69. The airtight seal is approximately 5.0 x 10 －９ 10. The ultracapacitor of claim 1, exhibiting a leakage rate of atm-cc / sec or less.

70. The airtight seal is approximately 5.0 x 10 －１０ 10. The ultracapacitor of claim 1, exhibiting a leakage rate of atm-cc / sec or less.

71. The ultracapacitor of claim 1 , wherein at least one contact is configured to mate with another contact of another ultracapacitor.

72. The ultracapacitor of claim 1 , wherein the storage cell includes a packaging member disposed over an exterior thereof.

73. 73. The ultracapacitor of claim 72, wherein the packaging member comprises one of PTFE and polyimide.

74. 10. The ultracapacitor of claim 1, wherein the volumetric leakage current is less than about 1000 mA / L within said temperature range.

75. 10. The ultracapacitor of claim 1, wherein the volumetric leakage current is less than about 1000 mA / L over a specified voltage range.

76. 1. A method for manufacturing an ultracapacitor, comprising: disposing an energy storage cell including an energy storage medium within the housing; and Configuring the ultracapacitor to operate within a temperature range of about 80° C. to about 210° C. A method comprising:

77. 77. The method of claim 76, wherein configuring comprises selecting an inwardly facing material for the housing that exhibits low chemical reactivity with the electrolyte.

78. 80. The method of claim 77, further comprising including an inwardly facing material on a substantial portion of the interior of the housing.

79. 78. The method of claim 77, wherein configuring includes selecting as the inwardly facing material at least one of aluminum, polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and a ceramic material.

80. 77. The method of claim 76, wherein configuring comprises forming the housing from a multi-layer material.

81. 81. The method of claim 80, wherein forming the housing from a multi-layer material includes disposing a weldable material on an exterior of the housing.

82. 77. The method of claim 76, wherein configuring includes fabricating at least one of a cap and a body of the housing.

83. 77. The method of claim 76, wherein configuring comprises disposing an inlet in the housing.

84. 83. The method of claim 82, wherein creating comprises disposing within the housing a seal including an insulator and an electrode insulated from the housing.

85. 85. The method of claim 84, wherein disposing a seal comprises disposing a glass-to-metal seal.

86. 85. The method of claim 84, wherein disposing a seal comprises disposing a hemispherical seal.

87. 86. The method of claim 85, wherein disposing the glass-to-metal seal comprises welding the glass-to-metal seal to an exterior surface of the housing.

88. 77. The method of claim 76, further comprising fabricating an energy storage cell.

89. 90. The method of claim 88, wherein fabricating the energy storage cell comprises bonding the energy storage medium to a current collector to obtain an electrode.

90. 90. The method of claim 89, wherein obtaining the electrode comprises joining a plurality of electrode components made by joining an energy storage medium to a current collector.

91. 91. The method of claim 90, wherein joining the plurality of electrode components comprises ultrasonically bonding a joining element to a current collector of one electrode component and to a current collector of another electrode component.

92. 90. The method of claim 88, wherein creating the energy storage cell comprises joining at least one lead to an electrode.

93. 93. The method of claim 92, wherein joining at least one lead to the electrode includes providing at least one reference mark on the electrode.

94. 93. The method of claim 92, wherein joining at least one lead to the electrode comprises positioning each lead at a respective fiducial mark.

95. 93. The method of claim 92, wherein joining the at least one lead comprises removing the energy storage medium from the current collector.

96. 93. The method of claim 92, wherein joining at least one lead comprises ultrasonically welding the lead to the current collector.

97. 90. The method of claim 88, wherein creating the energy storage cell comprises disposing a separator between the at least two electrodes.

98. 98. The method of claim 97, further comprising disposing each electrode with a separator.

99. 90. The method of claim 88, wherein creating the energy storage cell comprises packing at least two electrodes with a separator disposed therebetween.

100. 100. The method of claim 99, wherein packing includes rolling the storage cell into a rolled storage cell.

101. 90. The method of claim 88, wherein creating the energy storage cell includes placing a packaging member over the storage cell.

102. 77. The method of claim 76, wherein positioning the energy storage cell includes joining a plurality of leads together to provide a terminal.

103. 103. The method of claim 102, wherein combining a plurality of leads comprises arranging the leads together into a series of arranged leads, thereby forming a terminal.

104. 104. The method of claim 103, further comprising providing a packaging member around the series of arranged leads.

105. 104. The method of claim 103, further comprising providing a crease in the series of arranged leads.

106. 104. The method of claim 103, further comprising coupling the series of arranged leads to contacts of the housing.

107. 104. The method of claim 103, wherein the coupling comprises welding a series of arranged leads to the contacts.

108. 104. The method of claim 103, wherein the coupling comprises welding the series of arranged leads to one of a jumper and a bridge for coupling with contacts of the housing.

109. 77. The method of claim 76, further comprising electrically coupling at least one of the jumper and the bridge to contacts of the housing.

110. 110. The method of claim 109, further comprising disposing an insulating material substantially over the contacts inside the housing.

111. 77. The method of claim 76, further comprising sealing the energy storage cell in a housing.

112. 77. The method of claim 76, further comprising coupling at least one cap to the body to provide a housing.

113. 113. The method of claim 112, wherein the cap comprises one of a concave cap, a convex cap, and a planar cap.

114. 113. The method of claim 112, further comprising removing at least a portion of the multi-layer material in the housing to provide a bond.

115. 113. The method of claim 112, wherein sealing comprises at least one of pulse welding, laser welding, resistance welding, and TIG welding the housing components together.

116. 1. A method for manufacturing an ultracapacitor, comprising: disposing an energy storage cell including an energy storage medium within the housing; and Filling the housing with an electrolyte adapted to operate within a temperature range of about 80° C. to about 210° C. A method comprising:

117. 117. The method of claim 116, wherein the placing further comprises pretreating components of the ultracapacitor including at least one of the electrodes, separators, leads, assembled energy storage cells, and housing to reduce internal moisture.

118. 117. The method of claim 116, wherein pre-treatment comprises heating the selected components over a temperature range of about 100° C. to about 150° C. under a substantial vacuum.

119. 117. The method of claim 116, wherein the pre-treatment comprises heating the selected components over a temperature range of about 150° C. to about 300° C. under a substantial vacuum.

120. 117. The method of claim 116, wherein the placing occurs in a substantially inert environment.

121. 117. The method of claim 116, further comprising selecting a substantially purified electrolyte.

122. 117. The method of claim 116, wherein the substantially purified electrolyte comprises an electrolyte having a halide ion content of less than about 1000 ppm.

123. 117. The method of claim 116, wherein the substantially purified electrolyte comprises an electrolyte having a halide ion content of less than about 500 ppm.

124. 117. The method of claim 116, wherein the substantially purified electrolyte comprises an electrolyte having a halide ion content of less than about 100 ppm.

125. 117. The method of claim 116, wherein the substantially purified electrolyte comprises an electrolyte having a halide ion content of about 20 ppm or less.

126. 123. The method of claim 122, wherein the halide ions comprise at least one of chloride, bromide, fluoride, and iodide.

127. 117. The method of claim 116, wherein the total concentration of metal species in the electrolyte is less than about 1000 ppm.

128. 128. The method of claim 127, wherein the metal species comprises at least one of Br, Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb, Zn, an alloy of any of the foregoing, and an oxide of any of the foregoing.

129. 117. The method of claim 116, wherein the total concentration of impurities from at least one of the solvents in the electrolyte is less than about 1000 ppm.

130. 130. The method of claim 129, wherein the impurities comprise at least one of bromoethane, chloroethane, 1-bromobutane, 1-chlorobutane, 1-methylimidazole, ethyl acetate, and methylene chloride.

131. 117. The method of claim 116, wherein the total water content in the electrolyte is less than about 500 ppm.

132. 117. The method of claim 116, wherein the total water content in the electrolyte is less than about 100 ppm.

133. 117. The method of claim 116, wherein the total water content in the electrolyte is less than about 50 ppm.

134. 117. The method of claim 116, wherein the total water content in the electrolyte is less than about 20 ppm.

135. 117. The method of claim 116, wherein the cation of the electrolyte is selected from the group comprising 1-(3-cyanopropyl)-3-methylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1,3-bis(3-cyanopropyl)imidazolium, 1,3-diethoxyimidazolium, 1-butyl-1-methylpiperidinium, 1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium, 1-butyl-4-methylpyridinium, 1-butylpyridinium, 1-decyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium and 3-methyl-1-propylpyridinium.

136. 117. The method of claim 116, wherein the cation of the electrolyte is selected from the group comprising ammonium, imidazolium, oxazolium, phosphonium, piperidinium, pyrazinium, pyrazinium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, sulfonium, thiazolium, triazolium, guanidium, isoquinolinium, benzotriazolium, viologen-type and functional imidazolium cations.

137. At least one branched group (R ｘ 137. The method of claim 136, wherein said alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano, hydroxyl, sulfate, sulfonate and carbonyl groups are selected from the group consisting of: alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano, hydroxyl, sulfate, sulfonate and carbonyl groups.

138. 138. The method of claim 137, wherein the alkyl is selected from the group comprising saturated aliphatic groups, straight chain alkyl groups, branched chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups.

139. 138. The method of claim 137, wherein alkyl is selected from the group including methyl, ethyl, propyl, butyl, pentyl, hexyl, ethylhexyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

140. 138. The method of claim 137, wherein the heteroalkyl comprises an alkyl group containing at least one heteroatom.

141. 141. The method of claim 140, wherein the heteroatoms are selected from the group including oxygen, nitrogen and sulfur.

142. 138. The method of claim 137, wherein the alkyl and alkynyl groups comprise aliphatic groups.

143. 138. The method of claim 137, wherein the aliphatic group contains at least one of a double bond and a triple bond.

144. The anion of the electrolyte is -F － , -Cl － , -Br － , -I － , -OCH ３ － , -CN － , -SCN － , -C ２ H ３ O ２ － , -ClO － , -ClO ２ － , -ClO ３ － , -ClO ４ － , -NCO － , -NCS － , -NCSe － , -NCN － , -OCH(CH ３ ) ２ － , -CH ２ OCH ３ － , -COOH － , -OH － , -SOCH ３ － , -SO ２ CH ３ － , -SOCH ３ － , -SO ２ CF ３ － , -SO ３ H － , -SO ３ CF ３ － , -O(CF ３ ) ２ C ２ (CF ３ ) ２ O － , -CF ３ － , -CHF ２ － , -CH ２ F － , -CH ３ － , -NO ３ － , -NO ２ － , -SO ３ － , -SO ４ ２－ , -SF ５ － , -CB １１ H １２ － , -CB １１ H ６ C ｌ６ － , -CH ３ C.B. １１ H １１ － and -C ２ H ５ C.B. １１ H １１ － 117. The method of claim 116, selected from the group comprising:

145. The anion of the electrolyte is A-PO ４ － , -A-SO ２ － , A-SO ３ － , -A-SO ３ H － , -A-COO － , -A-CO － and A is one of a phenyl group, a substituted phenyl, an alkyl group, a substituted alkyl group, a negatively charged radical alkane, a halogenated alkane, and an ether.

146. 117. The method of claim 116, wherein the anion of the electrolyte comprises a plurality of substructures and respective numbers of substituents.

147. 117. The method of claim 116, wherein the electrolyte comprises a solvent.

148. 148. The method of claim 147, wherein the solvent comprises at least one of acetonitrile, amides, benzonitrile, butyrolactone, cyclic ethers, dibutyl carbonate, diethyl carbonate, diethyl ether, dimethoxyethane, dimethyl carbonate, dimethylformamide, dimethylsulfone, dioxane, dioxolane, ethyl formate, ethylene carbonate, ethyl methyl carbonate, lactones, linear ethers, methyl formate, methyl propionate, methyl tetrahydrofuran, nitriles, nitrobenzene, nitromethane, n-methylpyrrolidone, propylene carbonate, sulfolane, sulfones, tetrahydrofuran, tetramethylene sulfone, thiophenes, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, carbonates, gamma-butyrolactone, nitriles, and tricyanohexane.

149. 117. The method of claim 116, further comprising disposing an inlet in the housing to provide for filling.

150. 150. The method of claim 149, further comprising sealing the fill port once filling is complete.

151. 151. The method of claim 150, wherein sealing comprises fitting a suitable material to the inlet.

152. 152. The method of claim 151, further comprising welding the material fitted in the inlet to the housing.

153. 117. The method of claim 116, wherein filling comprises disposing an electrolyte over an inlet in the housing.

154. 154. The method of claim 153, wherein filling comprises drawing a vacuum at an inlet in the housing.

155. 155. The method of claim 154, wherein the vacuum is about 150 millitorr or less.

156. 155. The method of claim 154, wherein the vacuum is about 40 millitorr or less.

157. 117. The method of claim 116, wherein the filling occurs in a substantially inert environment.

158. An ultracapacitor including an energy storage cell and an electrolyte within a housing, the ultracapacitor having a moisture level within the housing of less than about 1000 ppm.

159. 159. The ultracapacitor of claim 158, wherein the level of moisture within the housing is less than about 500 ppm.

160. 159. The ultracapacitor of claim 158, wherein the level of moisture within the housing is less than about 350 ppm.

161. 159. The ultracapacitor of claim 158, wherein the moisture level in the electrodes of the ultracapacitor is less than about 350 ppm.

162. 159. The ultracapacitor of claim 158, wherein the moisture level in the separator of the ultracapacitor is less than about 160 ppm.

163. 159. The ultracapacitor of claim 158, wherein the moisture level in the electrolyte of the ultracapacitor is less than about 20 ppm.

164. 159. The ultracapacitor of claim 158, wherein the ultracapacitor has a halide content of less than about 1000 ppm.

165. 159. The ultracapacitor of claim 158, wherein the ultracapacitor has a halide content of less than about 500 ppm.

166. 159. The ultracapacitor of claim 158, wherein the ultracapacitor has a halide content of less than about 100 ppm.

167. An ultracapacitor including an energy storage cell and an electrolyte within a housing, the ultracapacitor having a level of halide impurities within the housing of less than about 1000 ppm.

168. 168. The ultracapacitor of claim 167, wherein the level of moisture within the housing is less than about 1000 ppm.

169. 168. The ultracapacitor of claim 167, wherein the level of moisture within the housing is less than about 500 ppm.

170. 168. The ultracapacitor of claim 167, wherein the level of moisture within the housing is less than about 350 ppm.

171. 168. The ultracapacitor of claim 167, wherein the moisture level in the electrodes of the ultracapacitor is less than about 350 ppm.

172. 168. The ultracapacitor of claim 167, wherein a moisture level in a separator of the ultracapacitor is less than about 160 ppm.

173. 168. The ultracapacitor of claim 167, wherein the moisture level in the electrolyte of the ultracapacitor is less than about 20 ppm.

174. Average Chloride (Cl － 168. The ultracapacitor of claim 167, wherein the Mn content is less than about 500 ppm.

175. Average fluoride (F － 168. The ultracapacitor of claim 167, wherein the Mn content is less than about 500 ppm.

176. 1. A method for characterizing contaminants in an ultracapacitor, comprising: Destroying the housing of the ultracapacitor to access the contents of the housing; Sampling the contents; and Analyzing the samples A method comprising:

177. 177. The method of claim 176, wherein destroying comprises at least one of drilling a hole in the housing and cutting through the housing.

178. 177. The method of claim 176, wherein the destroying is carried out in a substantially inert environment substantially free of contaminants.

179. 177. The method of claim 176, wherein the contents include at least one of an electrolyte, an electrode, a separator, and an inner surface of the housing.

180. 177. The method of claim 176, wherein the sampling comprises aspirating an electrolyte from within the ultracapacitor.

181. 177. The method of claim 176, wherein the sampling comprises adding an electrolyte containing a known concentration of an impurity to the ultracapacitor.

182. 191. The method of claim 190, wherein the sampling further comprises removing excess electrolyte for analysis.

183. 177. The method of claim 176, wherein sampling includes obtaining an aliquot of at least one of the electrode, the separator, and the inner surface of the housing.

184. 177. The method of claim 176, wherein the analyzing comprises performing at least one of the following methods: atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICPMS), ion chromatography (IC), X-ray fluorescence (XRF), pyrolysis, Raman spectroscopy, and the use of an ion selective electrode (ISE).

185. 177. The method of claim 176, wherein analyzing the contents further comprises weighing the contents and verifying the percentage of the total weight.

186. An ultracapacitor that exhibits a volumetric leakage current of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 100°C to about 150°C.

187. 187. The ultracapacitor of claim 186, having a volumetric leakage current of less than about 1 mA / cc.

188. 187. The ultracapacitor of claim 186, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

189. 187. The ultracapacitor of claim 186, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

190. 187. The ultracapacitor of claim 186, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

191. 187. The ultracapacitor of claim 186, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 F / cc.

192. 187. The ultracapacitor of claim 186, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

193. 187. The ultracapacitor of claim 186, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

194. 187. The ultracapacitor of claim 186, further exhibiting a volumetric ESR of about 1.5 ohm-cc to 200 ohm-cc.

195. 187. The ultracapacitor of claim 186, further exhibiting a volumetric ESR of about 150 ohm-cc to 2000 ohm-cc.

196. 187. The ultracapacitor of claim 186, further exhibiting a capacitance degradation of less than about 60% while held at a constant voltage for at least 20 hours.

197. 187. The ultracapacitor of claim 186, further exhibiting an increase in ESR of less than about 300% while held at a constant voltage for at least 20 hours.

198. 187. The ultracapacitor of claim 186, having a water content in an electrode of the ultracapacitor of less than about 1000 ppm.

199. 187. The ultracapacitor of claim 186, having a water content in an electrode of the ultracapacitor of less than about 500 ppm.

200. 187. The ultracapacitor of claim 186, having a moisture content in a separator of the ultracapacitor of less than about 1000 ppm.

201. 187. The ultracapacitor of claim 186, having a moisture content in a separator of the ultracapacitor of less than about 500 ppm.

202. 187. The ultracapacitor of claim 186, having a water content in an electrolyte of the ultracapacitor of less than about 500 ppm.

203. 187. The ultracapacitor of claim 186, comprising a hermetically sealed housing.

204. The seal is about 10 －５ (Standard He cc / s) ~ approx. 10 －９ 204. The ultracapacitor of claim 203, exhibiting a He leak rate (standard He cc / s) of.

205. The seal is about 10 －７ (Standard He cc / s) ~ approx. 10 －１０ 204. The ultracapacitor of claim 203, exhibiting a He leak rate (standard He cc / s) of.

206. 187. The ultracapacitor of claim 186, wherein a chloride content in one of the electrodes, electrolyte, and separator of the ultracapacitor is less than about 300 ppm.

207. 187. The ultracapacitor of claim 186, comprising a glass-to-metal seal disposed in a housing of the ultracapacitor.

208. An ultracapacitor that exhibits a volumetric leakage current of less than about 10 mA / cc while held at a substantially constant temperature within a temperature range of about 140°C to 180°C.

209. 209. The ultracapacitor of claim 208, having a volumetric leakage current of less than about 1 mA / cc.

210. 209. The ultracapacitor of claim 208, further exhibiting a volumetric leakage current of greater than about 0.001 mA / cc.

211. 209. The ultracapacitor of claim 208, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

212. 209. The ultracapacitor of claim 208, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

213. 209. The ultracapacitor of claim 208, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 F / cc.

214. 209. The ultracapacitor of claim 208, further exhibiting a volumetric ESR of about 20 mΩ·cc to about 200 mΩ·cc.

215. 209. The ultracapacitor of claim 208, further exhibiting a volumetric ESR of about 150 mΩ·cc to about 2 Ω·cc.

216. 209. The ultracapacitor of claim 208, further exhibiting a volumetric ESR of about 1.50 Ω·cc to about 200 Ω·cc.

217. 209. The ultracapacitor of claim 208, further exhibiting a volumetric ESR of about 150 Ω·cc to about 2000 Ω·cc.

218. 209. The ultracapacitor of claim 208, further exhibiting a capacitance degradation of less than about 60% while held at a constant voltage for at least 20 hours.

219. 209. The ultracapacitor of claim 208, further exhibiting an increase in ESR of less than about 300% while held at a constant voltage for at least 20 hours.

220. 209. The ultracapacitor of claim 208, having a water content in an electrode of the ultracapacitor of less than about 1000 ppm.

221. 209. The ultracapacitor of claim 208, having a water content in an electrode of the ultracapacitor of less than about 500 ppm.

222. 209. The ultracapacitor of claim 208, having a moisture content in a separator of the ultracapacitor of less than about 1000 ppm.

223. 209. The ultracapacitor of claim 208, having a moisture content in a separator of the ultracapacitor of less than about 500 ppm.

224. 209. The ultracapacitor of claim 208, having a water content in an electrolyte of the ultracapacitor of less than about 500 ppm.

225. 209. The ultracapacitor of claim 208, comprising a hermetically sealed housing.

226. The seal is about 10 －５ (Standard He cc / s) ~ approx. 10 －９ 226. The ultracapacitor of claim 225, exhibiting a He leak rate (standard He cc / s) of (standard He cc / s).

227. The seal is about 10 －７ (Standard He cc / s) ~ approx. 10 －１０ 226. The ultracapacitor of claim 225, exhibiting a He leak rate (standard He cc / s) of (standard He cc / s).

228. 209. The ultracapacitor of claim 208, wherein a chloride content in one of the electrodes, electrolyte, and separator of the ultracapacitor is less than about 300 ppm.

229. 209. The ultracapacitor of claim 208, comprising a glass-to-metal seal disposed in a housing of the ultracapacitor.

230. An ultracapacitor that exhibits a volumetric leakage current of less than about 10 mA / cc while held at a substantially constant temperature within a temperature range of about 170°C to 210°C.

231. 231. The ultracapacitor of claim 230, having a volumetric leakage current of less than about 1 mA / cc.

232. 231. The ultracapacitor of claim 230, further exhibiting a volumetric leakage current of greater than about 0.001 mA / cc.

233. 231. The ultracapacitor of claim 230, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

234. 231. The ultracapacitor of claim 230, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

235. 231. The ultracapacitor of claim 230, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 F / cc.

236. 231. The ultracapacitor of claim 230, further exhibiting a volumetric ESR of about 20 mΩ·cc to about 200 mΩ·cc.

237. 231. The ultracapacitor of claim 230, further exhibiting a volumetric ESR of about 150 mΩ·cc to about 2 Ω·cc.

238. 231. The ultracapacitor of claim 230, further exhibiting a volumetric ESR of about 1.50 Ω·cc to about 200 Ω·cc.

239. 231. The ultracapacitor of claim 230, further exhibiting a volumetric ESR of about 150 Ω·cc to about 2000 Ω·cc.

240. 231. The ultracapacitor of claim 230, further exhibiting a capacitance degradation of less than about 60% while held at a constant voltage for at least 20 hours.

241. 231. The ultracapacitor of claim 230, further exhibiting an increase in ESR of less than about 300% while held at a constant voltage for at least 20 hours.

242. 231. The ultracapacitor of claim 230, having a water content in an electrode of the ultracapacitor of less than about 1000 ppm.

243. 231. The ultracapacitor of claim 230, having a water content in an electrode of the ultracapacitor of less than about 500 ppm.

244. 231. The ultracapacitor of claim 230, having a moisture content in a separator of the ultracapacitor of less than about 1000 ppm.

245. 231. The ultracapacitor of claim 230, having a moisture content in a separator of the ultracapacitor of less than about 500 ppm.

246. 231. The ultracapacitor of claim 230, having a water content in an electrolyte of the ultracapacitor of less than about 500 ppm.

247. 231. The ultracapacitor of claim 230, comprising a hermetically sealed housing.

248. The seal is about 10 －５ (Standard He cc / s) ~ approx. 10 －９ 248. The ultracapacitor of claim 247, exhibiting a He leak rate (standard He cc / s) of (standard He cc / s).

249. The seal is about 10 －７ (Standard He cc / s) ~ approx. 10 －１０ 248. The ultracapacitor of claim 247, exhibiting a He leak rate (standard He cc / s) of (standard He cc / s).

250. 231. The ultracapacitor of claim 230, wherein a chloride content in one of the electrodes, electrolyte, and separator of the ultracapacitor is less than about 300 ppm.

251. 231. The ultracapacitor of claim 230, comprising a glass-to-metal seal disposed in a housing of the ultracapacitor.

252. 1. A method for providing a high temperature rechargeable energy storage device, comprising: selecting a high temperature rechargeable energy storage device (HTRESD) that exhibits an initial peak power density of 0.01 W / L to 100 kW / L and an endurance time of at least 20 hours when exposed to an ambient temperature in the temperature range of about 80° C. to about 210° C.; and Providing a storage device A method comprising:

253. 253. The method of claim 252, wherein the endurance time is assessed by a decline in peak power density over that time of about 50% or less, and the HTRESD is configured to be charged and discharged at least twice.

254. 253. The method of claim 252, wherein the HTRESD is an ultracapacitor.

255. 253. The method of claim 252, wherein the temperature range is from about 100°C to about 210°C.

256. 253. The method of claim 252, wherein the temperature range is from about 125°C to about 210°C.

257. 253. The method of claim 252, wherein the temperature range is from about 80°C to about 175°C.

258. 253. The method of claim 252, wherein the temperature range is from about 100°C to about 175°C.

259. 253. The method of claim 252, wherein the temperature range is from about 125°C to about 175°C.

260. 253. The method of claim 252, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 50 kW / L.

261. 253. The method of claim 252, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 10 kW / L.

262. 253. The method of claim 252, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 5 kW / L.

263. 253. The method of claim 252, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 2 kW / L.

264. 1. A method of using a high temperature rechargeable energy storage device (HTRESD), comprising: Obtaining HTRESD; and and at least one of cycling the HTRESD by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and holding a voltage across the HTRESD for 20 hours, such that the HTRESD exhibits an initial peak power density of 0.01 W / L to 150 kW / L and a life of at least 20 hours when operated at an ambient temperature within a temperature range of about 80° C. to about 210° C. A method comprising:

265. 265. The method of claim 264, wherein the durability is assessed by a decline in peak power density over time of about 50% or less, and the HTRESD is configured to be charged and discharged at least two times.

266. 265. The method of claim 264, wherein the HTRESD is an ultracapacitor.

267. 265. The method of claim 264, wherein the temperature range is from about 100°C to about 210°C.

268. 265. The method of claim 264, wherein the temperature range is from about 125°C to about 210°C.

269. 265. The method of claim 264, wherein the temperature range is from about 80°C to about 175°C.

270. 265. The method of claim 264, wherein the temperature range is from about 100°C to about 175°C.

271. 265. The method of claim 264, wherein the temperature range is from about 125°C to about 175°C.

272. 265. The method of claim 264, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 50 kW / L.

273. 265. The method of claim 264, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 10 kW / L.

274. 265. The method of claim 264, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 5 kW / L.

275. 265. The method of claim 264, wherein the HTRESD exhibits an initial peak power density of from about 0.01 W / L to about 2 kW / L.

276. 1. A method of using an ultracapacitor, the method comprising: obtaining an ultracapacitor including an electrolyte and two electrodes, each of the electrodes being in electrical communication with a current collector and separated from the other electrode by a separator; One of the charging and discharging of the ultracapacitor is about 0.1Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ resulting in an initial combination of peak power density and energy density in the range of The method of claim 1, wherein the ultracapacitor exhibits a durability time of at least 20 hours when exposed to an ambient temperature in a temperature range of about 80° C. to about 210° C., the durability being indicated by a decrease in peak power density of about 50% or less over that time, and the ultracapacitor is configured to be charged and discharged at least two times.

277. 277. The method of claim 276, wherein the temperature range is from about 80°C to about 175°C.

278. 277. The method of claim 276, wherein the temperature range is from about 80°C to about 150°C.

279. 277. The method of claim 276, wherein the temperature range is from about 80°C to about 125°C.

280. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

281. The combined range is approximately 1Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

282. The combined range is approximately 5Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

283. The combined range is approximately 10Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

284. The combined range is approximately 25Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

285. The combined range is approximately 50Wh·kW / L. ２ ~Approx. 100Wh・kW / L ２ The method of claim 276,

286. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 50Wh・kW / L ２ The method of claim 276,

287. The combined range is approximately 1Wh·kW / L. ２ ~Approx. 50Wh・kW / L ２ The method of claim 276,

288. The combined range is approximately 5Wh·kW / L. ２ ~Approx. 50Wh・kW / L ２ The method of claim 276,

289. The combined range is approximately 10Wh·kW / L. ２ ~Approx. 50Wh・kW / L ２ The method of claim 276,

290. The combined range is approximately 25Wh·kW / L. ２ ~Approx. 50Wh・kW / L ２ The method of claim 276,

291. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 25Wh・kW / L ２ The method of claim 276,

292. The combined range is approximately 1Wh·kW / L. ２ ~Approx. 25Wh・kW / L ２ The method of claim 276,

293. The combined range is approximately 5Wh·kW / L. ２ ~Approx. 25Wh・kW / L ２ The method of claim 276,

294. The combined range is approximately 10Wh·kW / L. ２ ~Approx. 25Wh・kW / L ２ The method of claim 276,

295. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 10Wh・kW / L ２ The method of claim 276,

296. The combined range is approximately 1Wh·kW / L. ２ ~Approx. 10Wh・kW / L ２ The method of claim 276,

297. The combined range is approximately 5Wh·kW / L. ２ ~Approx. 10Wh・kW / L ２ The method of claim 276,

298. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 5Wh・kW / L ２ The method of claim 276,

299. The combined range is approximately 1Wh·kW / L. ２ ~Approx. 5Wh・kW / L ２ The method of claim 276,

300. The combined range is approximately 0.1Wh·kW / L. ２ ~Approx. 1Wh・kW / L ２ The method of claim 276,

301. 1. A method of using an ultracapacitor, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 100° C. to about 150° C.; and and at least one of cycling the ultracapacitor by alternatively charging and discharging the ultracapacitor at least twice for a duration of 20 hours, and holding the voltage across the ultracapacitor for 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while the ultracapacitor is held at a substantially constant temperature in the range of about 100° C. to about 150° C. A method comprising:

302. 302. The method of claim 301, wherein the volumetric leakage current is less than about 1 mA / cc.

303. 302. The method of claim 301, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

304. The method of claim 301, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

305. The method of claim 301, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

306. 302. The method of claim 301, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

307. 302. The method of claim 301, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

308. 302. The method of claim 301, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

309. 302. The method of claim 301, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

310. 302. The method of claim 301, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

311. 302. The method of claim 301, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

312. 1. A method of using an ultracapacitor, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 140° C. to about 180° C.; and and at least one of cycling the ultracapacitor by alternatively charging and discharging the ultracapacitor at least twice for a duration of 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while the ultracapacitor is held at a substantially constant temperature in the range of about 140° C. to about 180° C., and holding the voltage across the ultracapacitor for 20 hours. A method comprising:

313. 313. The method of claim 312, wherein the volumetric leakage current is less than about 1 mA / cc.

314. 313. The method of claim 312, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

315. 313. The method of claim 312, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

316. 313. The method of claim 312, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

317. 313. The method of claim 312, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

318. 313. The method of claim 312, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

319. 313. The method of claim 312, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

320. 313. The method of claim 312, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

321. 313. The method of claim 312, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

322. 313. The method of claim 312, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

323. 1. A method of using an ultracapacitor, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 170° C. to about 210° C.; and and at least one of cycling the ultracapacitor by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and holding the voltage across the HTRESD for 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while held at a substantially constant temperature in the range of about 170° C. to about 210° C. A method comprising:

324. 324. The method of claim 323, wherein the volumetric leakage current is less than about 1 mA / cc.

325. 324. The method of claim 323, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

326. 324. The method of claim 323, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

327. 324. The method of claim 323, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

328. 324. The method of claim 323, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

329. 324. The method of claim 323, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

330. 324. The method of claim 323, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

331. 324. The method of claim 323, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

332. 324. The method of claim 323, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

333. 324. The method of claim 323, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

334. 1. A method for providing a high temperature rechargeable energy storage device, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 100° C. to about 150° C.; and cycling the ultracapacitor by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and / or holding the voltage across the HTRESD for 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while held at a substantially constant temperature in the range of about 100° C. to about 150° C.; and Providing a storage device A method comprising:

335. The method of claim 334, wherein the volumetric leakage current is less than about 1 mA / cc.

336. 335. The method of claim 334, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

337. The method of claim 334, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

338. The method of claim 334, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

339. The method of claim 334, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

340. 335. The method of claim 334, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

341. 335. The method of claim 334, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

342. 335. The method of claim 334, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

343. 335. The method of claim 334, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

344. 335. The method of claim 334, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

345. 1. A method for providing a high temperature rechargeable energy storage device, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 140° C. to about 180° C.; and cycling the ultracapacitor by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and / or holding the voltage across the HTRESD for 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while the ultracapacitor is held at a substantially constant temperature in the range of about 140° C. to about 180° C.; and Providing a storage device A method comprising:

346. The method of claim 345, wherein the volumetric leakage current is less than about 1 mA / cc.

347. The method of claim 345, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

348. The method of claim 345, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

349. The method of claim 345, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

350. The method of claim 345, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

351. 346. The method of claim 345, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

352. 346. The method of claim 345, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

353. 346. The method of claim 345, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

354. 346. The method of claim 345, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

355. 346. The method of claim 345, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

356. 1. A method for providing a high temperature rechargeable energy storage device, comprising: Obtaining an ultracapacitor that exhibits a volumetric leakage current (mA / cc) of less than about 10 mA / cc while held at a substantially constant temperature in the range of about 170° C. to about 210° C.; and cycling the ultracapacitor by alternatively charging and discharging the HTRESD at least twice for a duration of 20 hours, and / or holding the voltage across the HTRESD for 20 hours, such that the ultracapacitor exhibits an increase in ESR of less than about 300% after 20 hours while the ultracapacitor is held at a substantially constant temperature in the range of about 170° C. to about 210° C.; and Providing a storage device A method comprising:

357. The method of claim 356, wherein the volumetric leakage current is less than about 1 mA / cc.

358. 357. The method of claim 356, further exhibiting a volumetric leakage current of greater than about 0.0001 mA / cc.

359. The method of claim 356, further exhibiting a volumetric capacitance of about 6 F / cc to about 1 mF / cc.

360. The method of claim 356, further exhibiting a volumetric capacitance of about 10 F / cc to about 5 F / cc.

361. The method of claim 356, further exhibiting a volumetric capacitance of about 50 F / cc to about 8 mF / cc.

362. 357. The method of claim 356, further exhibiting a volumetric ESR of about 20 mΩ·cc to 200 mΩ·cc.

363. 357. The method of claim 356, further exhibiting a volumetric ESR of about 150 mΩ·cc to 2 Ω·cc.

364. 357. The method of claim 356, further exhibiting a volumetric ESR of about 1.5 Ω·cc to 200 Ω·cc.

365. 357. The method of claim 356, further exhibiting a volumetric ESR of about 150 Ω·cc to 2000 Ω·cc.

366. 357. The method of claim 356, further exhibiting a capacitance decrease of less than about 60% while held at a constant voltage.

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