KR102461542B1 - Advanced electrolyte systems and their use in energy storage devices - Google Patents

Abstract

An ultracapacitor comprising an energy storage cell immersed in an AES and disposed within a hermetically sealed housing, wherein the cell is electrically coupled with a positive contact and a negative contact, wherein the ultracapacitor is from about -40°C to about 210°C It is configured to output electrical energy within a temperature range of Methods of manufacture and use are provided.

Description

ADVANCED ELECTROLYTE SYSTEMS AND THEIR USE IN ENERGY STORAGE DEVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is filed on February 24, 2012 and is entitled "Electrolytes for Ultracapacitors", U.S. Provisional Patent Application No. 61/602,713, filed July 9, 2012 and titled This "High Temperature Energy Storage Device", PCT/US2012/045994, United States filed July 19, 2012 and entitled "Power Supply for Downhole Instruments" Benefit from priority from Patent Application Serial No. 13/553,716, and U.S. Provisional Application Serial No. 61/724,775, filed November 9, 2012, entitled "Electrolytes for Ultracapacitors". claim All of each of these disclosures is incorporated herein by reference to them.

Field of the Invention

FIELD OF THE INVENTION The invention disclosed herein relates to energy storage cells, and more particularly to an improved electrolyte system for use in such energy storage cells and related techniques for providing an electric double-layer capacitor operable at high temperatures. .

Energy storage cells are everywhere in our society. Although most people perceive an energy storage cell as simply a "battery", other types of cells should also be included within this context. For example, recently ultracapacitors have attracted a lot of attention because of their good properties. In short, many types of energy storage cells are known and currently in use.

Electrical double layer capacitors, also known as "supercapacitors", "supercapacitors", "pseudocapacitors", "electrochemical double layer capacitors" or "ultracapacitors" are capacitors that exhibit significantly improved performance over ordinary capacitors. One such parameter is energy density. In general, ultracapacitors have an energy density on the order of several thousand times greater than that of large-capacity electrolytic capacitors.

Capacitors are one of the key components in any electronic device and system. Traditional functions include supply voltage smoothing, energy source support, and filtering. Various industries are presented with difficult environments for the implementation of electronic products and capacitors.

For example, industries such as oil drilling, aerospace, aviation, military, and automotive have several applications that require electrical components to operate continuously at high temperatures (eg, at temperatures in excess of 80°C). that is considered This heat exposure, along with a variety of factors, functions to degrade the performance of energy storage systems at elevated temperatures and leads to premature degradation of the energy storage cell. Durability and safety are key requirements in typical aerospace and defense industry applications. There are applications such as engines, turbo fans, and control and sensing electronics being placed near the outer shell of a rocket engine. Automotive applications such as small gearboxes or built-in AC power supplies/starters also require durability and long life at elevated temperatures.

Electronic components used in industrial environments must be physically robust while meeting performance requirements. One of the challenges involved for designers and manufacturers of ultracapacitors is to obtain an electrolyte that not only functions reliably at high temperatures, but also functions reliably at both high temperatures and low temperatures. Unfortunately, the desirable properties of some electrolytes are not demonstrated or maintained at higher temperatures, and those that achieved durability at higher temperatures could not function reliably at lower temperatures. Therefore, what is needed is electrolytes for ultracapacitors that perform well in challenging environments. Preferably, the electrolytes should provide stable conductivity and low internal resistance as well as stable and high capacitance and stable and low leakage current over a wide range of temperatures.

In one embodiment, an ultracapacitor is disclosed. An ultracapacitor includes an energy storage cell and an enhanced electrolyte system (AES) in a hermetically sealed housing, wherein the cell is electrically coupled to a positive contact and a negative contact, wherein the ultracapacitor is from about -40°C to about 210°C is configured to operate at a temperature within a temperature range of

In yet another embodiment, a method for manufacturing an ultracapacitor is provided. The method includes placing an energy storage cell comprising an energy storage medium in a housing; and filling the housing with an enhanced electrolyte system (AES) such that the ultracapacitor is manufactured to operate within a temperature range of about -40°C to about 210°C.

In another embodiment, a method of using a high temperature rechargeable energy storage device (HTRESD) is provided. The method comprises the steps of obtaining a HTRESD comprising an enhanced electrolyte system (AES); and maintaining the voltage across the HTRESD, such that the HTRESD exhibits an initial peak power density of 0.01 W/liter to 150 kW/liter, such that the HTRESD operates at an ambient temperature in the temperature range of about -40°C to about 210°C; cycling the HTRESD by alternately charging and discharging the HTRESD at least twice.

In another embodiment, a method of using an ultracapacitor is provided. The method is characterized in that the method described herein exhibits a volumetric leakage current (mA/cc) of less than about 10 mA/cc while maintained at a substantially constant temperature within the range of about 100°C to about 150°C. obtaining a capacitor; and maintaining a voltage across the ultracapacitor such that the ultracapacitor exhibits an ESR increase of less than about 1,000% after at least one hour of use while the ultracapacitor is maintained at a substantially constant temperature within the range of about -40°C to about 210°C; cycling the ultracapacitor by alternately charging and discharging the ultracapacitor twice.

In yet another embodiment, a method of providing a high temperature rechargeable energy storage device to a user is provided. The method comprises an improved electrolyte system (AES) that exhibits an endurance period of at least 1 hour and an initial peak power density of 0.01 W/liter to 100 kW/liter when exposed to ambient temperature within a temperature range of about -40°C to about 210°C. selecting a HTRESD comprising; and delivering the storage device so that the HTRESD is provided to the user.

In another embodiment, a method of providing a high temperature rechargeable energy storage device to a user is provided. The method comprises obtaining any ultracapacitor described herein that exhibits a volumetric leakage current (mA/cc) of less than about 10 mA/cc while maintained at a substantially constant temperature within the range of about -40°C to about 210°C. step; and delivering the storage device so that the HTRESD is provided to the user.

In another embodiment, an improved electrolyte system (AES) is disclosed. AES comprises an ionic liquid comprising at least one anion and at least one cation and exhibits a halide content of less than 1,000 ppm and a moisture content of less than 100 ppm.

In another embodiment, an improved electrolyte system (AES) is disclosed. AES comprises an ionic liquid comprising at least one anion and at least one cation and at least one solvent and exhibits a halide content of less than 1,000 ppm and a moisture content of less than 1.000 ppm.

These and other features and advantages of the present invention are apparent from the following detailed description taken in conjunction with the accompanying drawings, which are not to be considered as limiting.
1 illustrates aspects of an example ultracapacitor;
2 is a block diagram depicting a plurality of carbon nanotubes (CNTs) grown on a substrate;
3 is a block diagram depicting the placement of a current collector onto the CNT of FIG. 3 to provide electrode elements;
Fig. 4 is a block diagram depicting the addition of a transfer tape to the electrode element of Fig. 3;
5 is a block diagram depicting an electrode element during a transfer process;
6 is a block diagram depicting an electrode element following transfer;
7 is a block diagram depicting an exemplary electrode fabricated from a plurality of electrode elements;
8 illustrates embodiments of key structures for cations that may be included in an exemplary ultracapacitor;
9 and 10 provide comparative data for exemplary ultracapacitors utilizing raw and purified electrolytes, respectively;
11 depicts an embodiment of a housing for an exemplary ultracapacitor;
12 illustrates an embodiment of a storage cell for an exemplary capacitor;
13 depicts a barrier disposed on the inner portion of the body of the housing;
14A and 14B, collectively referred to herein as FIG. 14, depict aspects of a cap relative to a housing;
15 depicts an assembly of an ultracapacitor according to the teachings herein;
16A and 16B are graphs depicting the performance of an ultracapacitor for an embodiment without a barrier and a similar embodiment including a barrier, respectively, collectively referred to herein as FIG. 16;
17 depicts a barrier disposed as a wrapper for a storage cell;
18A, 18B, and 18C, collectively referred to herein as FIG. 18, depict embodiments of a cap comprising a multilayer material;
19 is a cross-sectional view of an electrode assembly including a glass-to-metal seal;
Fig. 20 is a cross-sectional view of the electrode assembly of Fig. 19 installed in the cap of Fig. 18B;
21 depicts the arrangement of energy storage cells in an assembly;
22A, 22B, and 22C, collectively referred to herein as FIG. 22, depict embodiments of an assembled energy storage cell;
23 depicts the incorporation of polymer insulators into ultracapacitors;
24A, 24B, and 24C, collectively referred to herein as FIG. 24, depict template aspects for another embodiment of a cap for energy storage;
25 is a perspective view of an electrode assembly comprising a hemispherical shaped material;
26 is a perspective view of a cap including the electrode assembly of FIG. 25 installed on the template of FIG. 24;
Fig. 27 is a cross-sectional view of the cap of Fig. 26;
28 depicts the coupling of an electrode assembly to a terminal of a storage cell;
29 is a transparent isometric view of an energy storage cell disposed within a cylindrical housing;
30 is a side view of a storage cell showing the various layers of one embodiment;
31 is an isometric view of a rolled storage cell including fiducial marks for positioning a plurality of leads;
Fig. 32 is an isometric view of the storage cell of Fig. 31 when unpacked;
33 depicts a rolled storage cell comprising a plurality of leads;
34 depicts a given Z-fold within aligned leads (ie, terminal), coupled to a storage cell;
35-38 are graphs depicting the performance of example ultracapacitors;
39-43 are graphs depicting the performance of example ultracapacitors at 210°C;
44A and 44B depict performance for ultracapacitors with novel electrolyte material: 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide at 150° C. and 1.5 V, respectively. are capacitance and ESR graphs;
45A and 45B depict capacitance and ESR, respectively, for ultracapacitors with a novel electrolyte material: trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide at 150° C. and 1.5 V; graphs;
46A and 46B are capacitance and ESR graphs depicting performance for ultracapacitors with novel electrolyte material: butyltrimethylammonium bis(trifluoromethylsulfonyl)imide at 150° C. and 1.5 V, respectively; admit;
47A and 47B are capacitance and ESR graphs depicting performance for an ultracapacitor with an ionic liquid selected from the ionic liquids used to prepare the enhanced electrolyte combinations, respectively, at 125° C. and 1.5 V; ;
48A and 48B are capacitance and ESR graphs depicting performance for an ultracapacitor with 37.5% organic solvent ionic liquid (same as in FIG. 47) v/v, respectively, at 125° C. and 1.5 V; and
49 is an ESR graph depicting performance for an ultracapacitor with 37.5% organic solvent ionic liquid (same as in FIG. 47) v/v at -40°C and 1.5 V.

In this application, components (eg, electrode materials, electrolytes, etc.), conditions (eg, temperature, degrees of freedom from various impurities at various levels), and performance characteristics (eg, capacity after cycling compared to initial capacity, low Various variables are described, including but not limited to leakage current, etc.). It should be understood that any combination of these variables may define an embodiment of the invention. For example, the combination of a particular electrode material with a particular electrolyte, under a certain temperature range and with less than a certain amount of impurities, operating at a leakage current and capacity after a certain value of cycling—these variables are included as possibilities, but the particular combination is May not be explicitly stated - this is an embodiment of the present invention. Other combinations of articles, elements, conditions and/or methods may also be specifically selected from among the variables enumerated herein to define other embodiments that will be apparent to those skilled in the art.

The present invention, including improved electrolyte systems and their use, will be described with reference to the following definitions set forth below for convenience. Unless defined otherwise, the following terms used herein are defined as follows:

I. Definitions

When introducing elements of the invention or embodiment(s) thereof, the singular expressions are intended to mean that there is one or more of the elements. Similarly, the adjective "another" when used when introducing an element is intended to mean one or more elements. The terms "comprising", "comprising" and "having" are inclusive and are intended to mean that there may be additional elements in addition to the listed elements.

The terms “alkenyl” and “alkynyl” are art-recognized and refer to unsaturated aliphatic groups similar in length and possible substitution to the alkyls described below, but containing at least one double or triple bond, respectively.

The term “alkyl” is art-recognized and includes saturated aliphatic groups, including straight chain alkyl groups, branched chain alkyl groups, cycloalkyl (cycloaliphatic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups. may include In certain embodiments, a straight chain or branched chain alkyl has up to about 20 carbon atoms in its backbone (eg, C ₁ -C ₂₀ for straight chain, C ₁ -C ₂₀ for branched chain). have Likewise, cycloalkyls have from about 3 to about 10 carbon atoms in their ring structure, 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, ethyl hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

As used herein, "clad", "cladding" and similar terms refer to bonding dissimilar metals together. Cladding is often achieved by extruding two metals through a die as well as pressing or rolling the sheets together under high pressure. Other processes such as laser cladding may be used. The result is a multi-layered sheet of material, wherein the multiple layers of material are bonded together so that the material can function as a single sheet (eg, be formed as if a single sheet of homogeneous material was formed).

Conventionally, “contaminants” may be considered to be defined as any undesirable material that, if introduced, could adversely affect the performance of the ultracapacitor 10 . Also note that, generally herein, contaminants may be assessed as concentrations, such as ppm. Concentrations may be taken by weight, volume, sample weight, or in any other manner as suitably determined.

The term "cyano" is given its ordinary meaning in the art and refers to the group CN. The term “sulfate” is given its ordinary meaning in the art and refers to the group SO ₂ . The term “sulfonate” is given its ordinary meaning in the art and refers to the group SO ₃ X, where X can be an electron pair, hydrogen, alkyl or cycloalkyl. The term “carbonyl” is art-recognized and refers to the group C═O.

In general, the term “electrode” refers to an electrical conductor used to make contact with another material, often non-metallic, in a device that can be incorporated into an electrical circuit. In general, the term “electrode” as used herein refers to a current collector 2 and additional (such as an energy storage medium 1 ) that may be accompanied by the current collector 2 to provide the required functionality. components (eg energy storage medium 1 mating with current collector 2 to provide energy storage and energy transfer).

“Energy density” is (1/2) X (the square of the peak device voltage) X (the device capacitance divided by the weight or volume of the device).

As discussed herein, "hermetic" refers to a seal whose quality (i.e., leak rate) is defined in units of "atm-cc/sec", which are units of gas per second (e.g., gas per second) at ambient atmospheric pressure and temperature. For example, He) means one cubic centimeter. This is equivalent to the expression in "standard He-cc/second" units. Moreover, it is recognized that 1 atm-cc/sec is equivalent to 1.01325 mbar-liter/sec.

“Heteroalkenyl” and “heteroalkynyl” are art-recognized, and alkenyl and alkynyl, as described herein, wherein one or more atoms are heteroatoms (eg, oxygen, nitrogen, sulfur, etc.) refers to alkyl groups.

The term “heteroalkyl” is art-recognized and refers to alkyl groups as described herein in which one or more atoms are heteroatoms (eg, oxygen, nitrogen, sulfur, etc.). For example, an alkoxy group (eg, -OR) is a heteroalkyl group.

By convention, the terms “internal resistance” and “effective series resistance” and “ESR” are terms known in the art to denote the resistive nature of a device, and are used herein interchangeably.

By convention, the term "leakage current" generally refers to the current drawn by a capacitor measured after a given period of time. This measurement is performed when the capacitor terminals are held at a substantially fixed potential difference (terminal voltage). In the evaluation of leakage current, a typical period is 72 hours, although different periods may be used. Note that leakage current for prior art capacitors generally increases with an increase in the volume and surface area of the energy storage medium and a concomitant increase in the interior surface area of the housing. In general, it is believed that increasing leakage current is indicative of a progressively increasing rate of response within the ultracapacitor 10 . Performance requirements for leakage current are usually defined by the prevailing environmental conditions for a particular application. For example, with an ultracapacitor 10 having a volume of 20 mL, the practical limit for leakage current may drop below 200 mA.

The "lifetime" of a capacitor is also generally defined by a particular application, typically expressed as a certain percentage increase in leakage current or deterioration of another parameter such as capacitance (suitable or limited for a given application) or internal resistance. For example, in one embodiment, the lifetime of a capacitor in an automotive field application may be defined as the time at which the leakage current increases to 200% of its initial (start-of-life or "BOL") value. In another example, the lifetime of a capacitor in an oil and gas sector application can be defined as the time during which any of the following occurs: the capacitance drops to 50% of its BOL value, and the internal resistance drops to 200% of its BOL value. , and the leakage increases to 200% of its BOL value. By convention, the terms "durability" and "reliability" of a device, as used herein generally, relate to the lifetime of the device as defined above.

The "operating temperature range" of a device generally relates to the temperature range within which a certain level of performance is maintained, and is generally determined for a given application. For example, in one embodiment, the operating temperature range for oil and gas field applications is that the resistance of the device is less than about 1,000% of the resistance of the device at 30°C and the capacitance is greater than about 10% of the capacitance at 30°C. can be defined as the temperature range of

In some cases, the operating temperature range specification provides a lower limit of useful temperatures, while the lifetime specification provides an upper limit of useful temperatures.

"Peak power density" is (1/4) X (the square of the peak device voltage divided by the effective series resistance of the device divided by the weight or volume of the device).

As mentioned herein, "volumetric leakage current" of ultracapacitor 10 generally refers to "leakage current divided by the volume of ultracapacitor 10, for example in mA/cc". Similarly, the “volume capacitance” of the ultracapacitor 10 generally refers to the capacitance of the ultracapacitor 10 divided by the volume of the ultracapacitor 10, for example in F/cc Also, "volume ESR" of the ultracapacitor 10 generally refers to the product of the ESR of the ultracapacitor 10 and the volume of the ultracapacitor 10, for example, Ohm·cc can be expressed in units of

By convention, the expression "may/may" as used herein is to be construed as optional, and "comprises" other options (i.e., steps, substances, components, mixtures, etc.) should be construed as not excluding; It does not imply a "should" requirement, rather it is merely an accidental or circumstantial preference. Other similar terms are used in the usual conventional manner.

As discussed herein, terms such as "adapt", "configure", "build", and the like refer to applications of any of the techniques disclosed herein, as well as other similar techniques (now known or may be devised later). may be considered to provide the intended result.

II. Capacitors of the present invention

Capacitors are disclosed herein that provide users with improved performance over a wide temperature range. For example, a capacitor of the present invention comprising the improved electrolyte systems described herein may be operable at temperatures ranging from as low as about -40°C to as high as about 210°C.

In general, the capacitors of the present invention comprise an energy storage medium adapted to provide a combination of high reliability, wide operating temperature range, high power density and high energy density when compared to prior art devices. The capacitor comprises electrolytes 6 selected only from the improved electrolyte systems described herein, comprising components configured to ensure operation over a temperature range. The combination of construction, energy storage medium, and improved electrolyte systems provides the robust capacitors of the present invention that withstand operation under extreme conditions with improved properties and better performance and durability over conventional capacitors.

Accordingly, the present invention provides an ultracapacitor comprising an enhanced electrolyte system (AES) and an energy storage cell in a hermetically sealed housing, wherein the cell is electrically coupled to a positive contact and a negative contact, wherein the ultracapacitor comprises: from about -40°C to about 210°C; about -35°C to about 210°C; about -40°C to about 205°C; about -30°C to about 210°C; about -40°C to about 200°C; about -25°C to about 210°C; about -40°C to about 195°C; about -20°C to about 210°C; about -40°C to about 190°C; about -15°C to about 210°C; about -40°C to about 185°C; about -10°C to about 210°C; about -40°C to about 180°C: about -5°C to about 210°C; about -40°C to about 175°C; about 0° C. to 210° C.; about -40°C to about 170°C; from about 5°C to about 210°C; about -40°C to about 165°C; about 10° C. to about 210° C.; about -40 to about 160°C; about 15° C. to about 210° C.; about -40°C to about 155°C; about 20° C. to about 210° C.; It is configured to operate at a temperature within a temperature range of about -40°C to about 150°C (“operating temperature”).

In one particular embodiment, the AES comprises a novel electrolyte material (NEE), for example wherein the NEE is adapted for use in high temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about 80°C to about 210°C, such as within a temperature range of about 80°C to about 150°C.

In one particular embodiment, the AES comprises a highly purified electrolyte, eg, wherein the highly purified electrolyte is suitable for use in high temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about 80°C to about 210°C.

In one particular embodiment, the AES comprises an improved electrolyte combination, eg, wherein the improved electrolyte combination is adapted for use in both high and low temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about -40°C to about 150°C.

Accordingly and as noted above, the advantages over existing electrolytes of known energy storage devices are selected from one or more of the following improvements: reduced total resistance, increased long-term stability of resistance, increased total capacitance, of capacitance. Increased long-term safety, increased energy density, increased voltage stability, reduced vapor pressure, wider temperature range performance for discrete capacitors, increased temperature endurance for discrete capacitors, increased ease of manufacture and improved cost effectiveness.

In certain embodiments of the ultracapacitor, the energy storage cell includes a positive electrode and a negative electrode.

In certain embodiments of the ultracapacitor, at least one of the electrodes comprises a carbonaceous energy storage medium, eg, wherein the carbonaceous energy storage medium comprises carbon nanotubes. In certain embodiments, the carbonaceous energy storage medium may include at least one of activated carbon, carbon fiber, rayon, graphene, airgel, carbon cloth, and carbon nanotubes.

In certain embodiments of the ultracapacitor, each electrode includes a current collector.

In certain embodiments of the ultracapacitor, the AES is purified to reduce the impurity content. In certain embodiments of the ultracapacitor, the content of halide ions in the electrolyte is less than about 1,000 ppm, such as less than about 500 ppm, such as less than about 100 ppm, such as less than about 50 ppm. In certain embodiments, the halide ion in the electrolyte is selected from one or more of the halide ions selected from the group consisting of chloride, bromide, fluoride and iodide. In certain embodiments, the total concentration of impurities in the electrolyte is less than about 1,000 ppm. In certain embodiments, the impurities are selected from one or more of the group consisting of bromoethane, chloroethane, 1-bromobutane, 1-chlorobutane, 1-methylimidazole, ethyl acetate and methylene chloride.

In certain embodiments of the ultracapacitor, the total concentration of metallic species in the electrolyte is less than about 1,000 ppm. In certain embodiments, the metallic species is selected from one or more metals selected from the group consisting of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. In another specific embodiment, the metallic species is selected from alloys of one or more of the metals selected from the group consisting of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. In another specific embodiment, the metallic species is selected from oxides of one or more of the metals selected from the group consisting of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. .

In certain embodiments of the ultracapacitor, the total moisture content in the electrolyte is less than about 500 ppm, such as less than about 100 ppm, such as less than about 50 ppm, such as less than about 20 ppm.

In certain embodiments of the ultracapacitor, the housing includes a barrier disposed on a substantial portion of its interior surface. In certain embodiments, the barrier comprises at least one of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE). In certain embodiments, the barrier comprises a ceramic material. The barrier may also include a material that exhibits corrosion resistance, desired dielectric properties, and low electrochemical reactivity. In certain embodiments of the barrier, the barrier comprises multiple layers of material.

In certain embodiments of the ultracapacitor, the housing comprises a multilayer material, eg, the multilayer material comprises a first material clad onto a second material. In certain embodiments, the multilayer material comprises at least one of steel, tantalum and aluminum.

In certain embodiments of the ultracapacitor, the housing includes at least one hemispheric seal.

In certain embodiments of the ultracapacitor, the housing includes at least one glass-to-metal seal, for example where a pin of the glass-to-metal seal provides one of the contacts. In certain embodiments, the glass-to-metal seal is a feed- consisting of a material selected from the group consisting of iron-nickel-cobalt alloy, nickel iron alloy, tantalum, molybdenum, niobium, tungsten, and stainless and titanium foam. Including feed-through. In another specific embodiment, the glass-to-metal seal comprises at least one selected from the group consisting of nickel, molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon, and tungsten and alloys thereof. It includes a body composed of a material of

In certain embodiments of the ultracapacitor, the energy storage cell includes a separator to provide electrical isolation between the positive electrode and the negative electrode, for example wherein the separator is polyamide, polytetrafluoroethylene (PTFE), polyether a material selected from the group consisting of ether ketone (PEEK), aluminum oxide (Al ₂ O ₃ ), fiberglass, fiberglass reinforced plastic, or combinations thereof. In certain embodiments, the separator is substantially free of moisture. In another specific embodiment, the separator is substantially hydrophobic.

In certain embodiments of the ultracapacitor, the hermetic seal may have a leak rate of about 5.0x10 ^-6 atm-cc/sec or less, such as about 5.0x10 ^-7 atm-cc/sec or less, such as about A leak rate of 5.0x10 ^-8 atm-cc/sec or less, for example, a leak rate of about 5.0x10 ^-9 atm-cc/sec or less, for example, a leak rate of about 5.0x10 ^-10 atm-cc/sec or less. indicates.

In certain embodiments of the ultracapacitor, at least one contact is configured to mate with another contact of another ultracapacitor.

In certain embodiments of the ultracapacitor, the storage cell includes a wrapper disposed on its exterior, eg, the wrapper includes one of PTFE and polyimide.

In certain embodiments of the ultracapacitor, the volumetric leakage current is less than about 10 amperes per liter within a temperature range.

In certain embodiments of the ultracapacitor, the volume leakage current is from about 0 Volts to about 4 Volts, such as from about 0 Volts to about 3 Volts, such as from about 0 Volts to about 2 Volts, such as from about 0 Volts to It is less than about 10 amps per liter over the specified voltage range of about 1 Volt. In certain embodiments of the ultracapacitor, the level of moisture in the housing is less than about 1,000 ppm, such as less than about 500 ppm, such as less than about 350 ppm.

In certain embodiments of the ultracapacitor, the moisture content at the electrode of the ultracapacitor is less than about 1,000 ppm, such as less than about 500 ppm, such as less than about 350 ppm.

In certain embodiments of the ultracapacitor, the water content in the separator of the ultracapacitor is less than about 1,000 ppm, such as less than about 500 ppm, such as less than about 160 ppm.

In certain embodiments of the ultracapacitor, the chloride content is less than about 300 ppm for one of the components selected from the group consisting of an electrode, an electrolyte, and a separator.

In certain embodiments of the ultracapacitor, the volume leakage current (mA/cc) of the ultracapacitor is less than about 10 mA/cc while maintained at a substantially constant temperature, eg, about 1 while maintained at a substantially constant temperature. less than mA/cc. In a special embodiment,

In certain embodiments of the ultracapacitor, the volume leakage current of the ultracapacitor is greater than about 0.0001 mA/cc while maintained at a substantially constant temperature.

In certain embodiments of the ultracapacitor, the volume capacitance of the ultracapacitor is from about 6 F/cc to about 1 mF/cc; from about 10 F/cc to about 5 F/cc; or from about 50 F/cc to about 8 F/cc.

In certain embodiments of the ultracapacitor, the volume ESR of the ultracapacitor may be between about 20 mOhm·cc and 200 mOhm·cc; about 150 mOhm·cc to 2 Ohm·cc; about 1.5 Ohm-cc to 200 Ohm-cc; from about 150 Ohm-cc to 2000 Ohm-cc.

In certain embodiments of the ultracapacitor, the ultracapacitor exhibits a capacitance reduction of less than about 90% while maintained at a substantially constant voltage and operating temperature. In a particular embodiment, the ultracapacitor is for at least 1 hour, such as at least 10 hours, such as at least 50 hours, such as at least 100 hours, such as at least 200 hours, such as at least exhibit a capacitance reduction of less than about 90% while maintained at a substantially constant voltage and operating temperature for 300 hours, such as at least 400 hours, such as at least 500 hours, such as at least 1,000 hours.

In certain embodiments of the ultracapacitor, the ultracapacitor is for at least 1 hour, such as at least 10 hours, such as at least 50 hours, such as at least 100 hours, such as at least 200 hours, e.g. an increase in ESR of less than about 1,000% while maintained at a substantially constant voltage and operating temperature for at least 300 hours, such as at least 400 hours, such as at least 500 hours, such as at least 1,000 hours. indicates.

For example, as illustrated in FIG. 1 , an exemplary embodiment of a capacitor is shown. In this case, the capacitor is "ultracapacitor 10". An exemplary ultracapacitor 10 is an electric double-layer capacitor (EDLC). Ultracapacitor 10 may be embodied in several different form factors (ie, may exhibit a particular appearance). Examples of potentially useful form factors include cylindrical cells, annular or ring shaped cells, stacks of flat prism cells including flat prism cells or box cells, and flat prisms having a shape to accommodate a particular geometry, such as a bent space. contains cells. A cylindrical form factor may be most useful when associated with a cylindrical system or a system that is mounted on a cylindrical form factor or has a cylindrical cavity. An annular or ring-shaped form factor may be most useful when it is ring-shaped, mounted on a ring-shaped form factor, or associated with a system having a ring-shaped cavity. A flat prismatic form factor may be most useful when it is rectangular in shape, mounted on a rectangular shape form factor, or associated with a system having a rectangular shaped cavity.

Although generally disclosed herein in terms of a "jelly roll" application (ie, storage cell 12 configured for a cylindrical housing 7), rolled storage cell 23 may be of any shape desired. can take For example, as opposed to winding the storage cell 12 , folding of the storage cell 12 may be performed to provide a rolled storage cell 23 . Other types of assemblies may be used. As an example, the storage cell 12 may be a flat cell, referred to as a coin type, pouch type, or prism type of cell. Accordingly, rolling is only one option for assembly of the rolled storage cells 23 . Thus, although described herein in terms of a “rolled storage cell 23”, it is not limited thereto. The term “rolled storage cell 23” may be considered to generally encompass any suitable form of packaging or packing the storage cell 12 to fit snugly within a given housing 7 design.

Several types of ultracapacitor 10 may be combined together. The various forms may be joined using known techniques such as welding the contacts together, using at least one mechanical connector, placing the contacts in electrical contact with each other, and the like. The plurality of ultracapacitors 10 may be electrically connected in at least one of a parallel and a series manner.

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

There may be a variety of circumstances in which the ultracapacitor 10 is particularly useful. For example, in automotive applications, an ambient temperature of 105° C. may be realized (where the actual lifetime of the capacitor will be in the range of about 1 to 20 years). In some downhole applications, such as geothermal well drilling, ambient temperatures above 300°C can be reached (where the actual lifetime of the capacitor will range from about 1 hour to about 10,000 hours) .

The components of the ultracapacitors of the present invention will now be discussed in turn.

A. Improved Electrolyte Systems of the Invention

The improved electrolyte systems of the present invention provide for the electrolyte component of the ultracapacitors of the present invention, denoted "electrolyte 6" in FIG. 1 . The electrolyte 6 fills the empty spaces in and between the electrodes 3 and the separator 5 . In general, the improved electrolyte systems of the present invention comprise native electrolytes, purified and improved electrolytes, or combinations thereof, wherein the electrolyte 6 is, for example, composed of one or more salts or ionic liquids. A substance that separates into electrically charged ions (ie positively charged cations and negatively charged anions) and may also include a solvent. In the improved electrolyte systems of the present invention, such electrolyte components are selected based on enhancement of specific performance and durability characteristics, and also one that dissolves the material to create a mixture with novel and useful electrochemical stability and performance. It can be combined with the above solvents.

The improved electrolyte systems of the present invention are of the present invention beyond conventional energy storage devices (e.g., energy storage devices comprising electrolytes not disclosed herein, or energy storage devices comprising electrolytes of insufficient purity). Unique and distinct advantages of ultracapacitors can be achieved. These advantages include improvements in both performance and durability characteristics, such as one or more of the following: reduced total resistance, increased long-term stability of the resistance (e.g., in increased material resistance over time at a given temperature). ), increased total capacitance, long-term stability of the layered capacitance (e.g., decrease in capacitance of a reduced capacitor over time at a given temperature), increased energy density (e.g. supporting higher voltages) and/or by leading to higher capacitance), increased voltage stability, reduced vapor pressure, wider temperature range performance for individual capacitors (e.g., significant drop in capacitance and/or ESR when transitioning between two temperatures) no increase of, e.g., no greater than 90% decrease in capacitance and/or no 1000% increase in ESR when transitioning from about +30 °C to about -40 °C), increased temperature endurance for individual capacitors (e.g. , less than 50% decrease in capacitance at a given temperature after a given time and/or a 100% increase in ESR at a given temperature after a given time, and/or less than 10 A/L leakage current at a given temperature after a given time, e.g. For example less than 40% decrease in capacitance and/or 75% increase in ESR, and/or less than 5 A/L leakage current, for example less than 30% decrease in capacitance and/or 50% increase in ESR, and/or or leakage current less than 1A/L); increased ease of manufacture (e.g., by having a reduced vapor pressure and thus a better yield and/or a more efficient way to fill a capacitor with electrolyte), and improved cost effectiveness (e.g., by having a material that is cheaper than other materials) by filling the space). For the sake of clarity, performance characteristics relate to characteristics related to the usability of a device at a given point of use that are similar and suitable for comparison among materials at a given point of use, whereas durability characteristics relate to such characteristics over time. It is related to characteristics related to the ability to maintain them. The performance and durability examples above will serve to provide context for what is considered herein "significant changes in performance or durability."

For clarity and generally, reference to “electrolyte 6” as used herein for inclusion in energy storage devices of the present invention refers to the improved electrolyte systems of the present invention.

The properties of the AES or electrolyte 6 include high conductivity over a wide temperature range and excellent electrical performance exhibited, as well as increased capacitance, reduced equivalent series resistance (ESR), high thermal stability, low glass transition temperature (Tg). , improved viscosity, and certain rhoepectic or thixotropic properties (eg, temperature dependent properties). By way of example, the electrolyte 6 may have a high level of fluidity or, in contrast, may be substantially solid, ensuring separation of the electrodes 3 .

The improved electrolyte system of the present invention provides the novel electrolytes described herein for use in high temperature ultracapacitors, highly purified electrolytes for use in high temperature ultracapacitors, and use in the temperature range of -40°C to 210°C. The improved electrolyte combinations suitable for the following include no significant degradation in performance or durability over all temperatures.

Although the disclosure provided herein focuses on the application of the improved electrolyte system disclosed herein to ultracapacitors, these improved electrolyte systems may be applied to any energy storage device.

i. New Electrolyte Materials (NEE)

The improved electrolyte system (AES) of the present invention, in one embodiment, includes certain novel electrolytes for use in high temperature ultracapacitors. In this regard, maintaining purity and low moisture is related to the degree of performance of energy storage 10 ; and hydrophobic materials, it has been found that using electrolytes found to exhibit greater purity and lower water content is advantageous in obtaining improved performance. Such electrolytes may be prepared in a temperature range from about 80°C to about 210°C, for example from about 80°C to about 200°C, such as from about 80°C to about 190°C, such as from about 80°C to about 180°C. , e.g., from about 80 °C to about 170 °C, such as from about 80 °C to about 160 °C, such as from about 80 °C to about 150 °C, such as from about 85 °C to about 145 °C, e.g. For example, from about 90°C to about 140°C, such as from about 95°C to about 135°C, such as from about 100°C to about 130°C, such as from about 105°C to about 125°C, such as , exhibits excellent performance characteristics at about 110°C to about 120°C.

Accordingly, novel electrolyte materials useful as advanced electrolyte systems (AESs) include species containing cations (eg, the cations shown in FIG. 8 and disclosed herein) and anions, or combinations of such species. In some embodiments, such species include nitrogen-containing, oxygen-containing, phosphorus-containing, and/or sulfur-containing cations, including heteroaryl and heterocyclic cations. In one set of embodiments, the enhanced electrolyte system (AES) is ammonium, imidazolium, oxazolium, phosphonium, piperidinium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, alcohol species comprising a cation selected from the group consisting of phonium, thiazolium, triazolium, guanidium, isoquinolinium, benzotriazolium and viologen-type cations, any of may be substituted with a substituent as disclosed herein. In one embodiment, the novel electrolyte materials useful for the improved electrolyte system (AES) of the present invention are the cations shown in Figure 8 selected from the group consisting of phosphonium, piperidinium and ammonium, wherein various branching groups are present. R _X (eg, R ₁ , R ₂ , R ₃ , ... R _X ) is alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano , hydroxyl, sulfate, sulfonate and carbonyl, any of which is optionally substituted, and at least two R _X are not H (i.e., the selection and orientation of the R groups is to produce the cationic species shown in Figure 8); and any combination of anions selected from the group consisting of tetrafluoroborate, bis(trifluoromethylsulfonyl)imide, tetracyanoborate, and trifluoromethanesulfonate.

For example, given the above combinations of cations and anions, in certain embodiments, AES is trihexyltetradecylphosphonium, bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpipe and lithium bis(trifluoromethylsulfonyl)imide and butyltrimethylammonium bis(trifluoromethylsulfonyl)imide. Supporting improved performance characteristics over the temperature range as shown by capacitance and ESR measurements over time, data showing high temperature utility and long-term durability are presented in Figures 44a and b, 45a and b, and 46a and b. is provided

In certain embodiments, the AES is trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the AES is 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the AES is butyltrimethylammonium bis(trifluoromethylsulfonyl)imide.

In another embodiment, the novel electrolyte materials useful for the improved electrolyte system (AES) of the present invention are cations shown in Figure 8 selected from the group consisting of imidazolium and pyrrolidinium, wherein the various branching groups R _X (eg, R ₁ , R ₂ , R ₃ , ... R _X ) is alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, halo, amino, nitro, cyano, hydro may be selected from the group consisting of hydroxyl, sulfate, sulfonate and carbonyl, any of which may be optionally substituted, and at least two R _X are not H (i.e., the selection and orientation of the R groups is adapted to produce the cationic species shown in Figure 8); and any combination of anions selected from the group consisting of tetrafluoroborate, bis(trifluoromethylsulfonyl)imide, tetracyanoborate, and trifluoromethanesulfonate. In one particular embodiment, two R _X other than H are alkyl. Moreover, the indicated cations exhibit high thermal stability as well as high conductivity over a wide range of temperatures, and exhibit excellent electrochemical performance.

For example, given the combinations of cations and anions, in certain embodiments, AES is 1-butyl-3-methylimidazolium tetrafluoroborate; 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium tetrafluoroborate; 1-ethyl-3-methylimidazolium tetracyanoborate; 1-hexyl-3-methylimidazolium tetracyanoborate; 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide; 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate; 1-butyl-1-methylpyrrolidinium tetracyanoborate; and 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

In one embodiment, the AES is 1-butyl-3-methylimidazolium tetrafluoroborate.

In one embodiment, the AES is 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

In one embodiment, the AES is 1-ethyl-3-methylimidazolium tetrafluoroborate.

In one embodiment, the AES is 1-ethyl-3-methylimidazolium tetracyanoborate.

In one embodiment, the AES is 1-hexyl-3-methylimidazolium tetracyanoborate.

In one embodiment, the AES is 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

In one embodiment, the AES is 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate.

In one embodiment, the AES is 1-butyl-1-methylpyrrolidinium tetracyanoborate.

In one embodiment, the AES is 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

In another specific embodiment, one of the two R _X other than H is alkyl, eg, methyl, and the other is alkyl substituted with alkoxy. Moreover, in the molecule, cations having an N,O-acetal skeleton structure of Formula 1 have high electrical conductivity, and are included among these cations, and an ammonium cation having a pyrrolidine skeleton and an N,O-acetal group is an organic solvent. It has been found that they have particularly high electrical conductivity and solubility, and support relatively high voltages. Accordingly, in one embodiment, the improved electrolyte system comprises a salt of the formula:

<Formula I>

Here, R ₁ and R ₂ may be the same or different, and each is alkyl, and X ⁻ is an anion. In some embodiments, R ₁ is straight or branched chain alkyl having 1 to 4 carbon atoms, R ₂ is methyl or ethyl, and X ⁻ is a cyanoborate containing anion (11). In certain embodiments, X ⁻ includes [B(CN)] ₄ and R ₂ is one of a methyl group and an ethyl group. In another specific embodiment, R ₁ and R ₂ are both methyl. Also, in one embodiment, a cyanoborate anion (11) suitable for the improved electrolyte system of the present invention, X ^- is [B(CN)4] ^- or [BFn(CN)4-n] ^- , where n = 0, 1, 2 or 3).

Examples of cations of the AES of the present invention comprising a novel electrolyte material of formula I and consisting of a cyanoborate anion and a quaternary ammonium cation represented by formula 1 are N-methyl-N-methoxymethylpyrrolidinium (N- Methoxymethyl-N-methylpyrrolidinium), N-ethyl-N-methoxymethylpyrrolidinium, N-methoxymethyl-N-n-propylpyrrolidinium, N-methoxymethyl-N-iso-propylpy Rollidinium, N-n-butyl-N-methoxymethylpyrrolidinium, N-iso-butyl-N-methoxymethylpyrrolidinium, N-tert-butyl-N-methoxymethylpyrrolidinium, N-ethoxy Methyl-N-methylpyrrolidinium, N-ethyl-N-ethoxymethylpyrrolidinium (N-ethoxymethyl-N-ethylpyrrolidinium), N-ethoxymethyl-N-n-propylpyrrolidinium, N -ethoxymethyl-N-iso-propylpyrrolidinium, N-n-butyl-N-ethoxymethylpyrrolidinium, N-iso-butyl-N-ethoxymethylpyrrolidinium and N-tert-butyl-N- ethoxymethylpyrrolidinium. Other examples are N-methyl-N-methoxymethylpyrrolidinium (N-methoxymethyl-N-methylpyrrolidinium), N-ethyl-N-methoxymethylpyrrolidinium and N-ethoxymethyl-N -Contains methylpyrrolidinium.

Further examples of cations of formula 1 combined with additional anions are N-methyl-N-methoxymethylpyrrolidinium tetracyanoborate (N-methoxymethyl-N-methylpyrrolidinium tetracyanoborate), N -Ethyl-N-methoxymethylpyrrolidinium tetracyanoborate, N-ethoxymethyl-N-methylpyrrolidinium tetracyanoborate, N-methyl-N-methoxymethylpyrrolidinium bistrifluoromethane Sulfonylimide, (N-methoxymethyl-N-methylpyrrolidinium bistrifluoromethanesulfonylimide), N-ethyl-N-methoxymethylpyrrolidinium bistrifluoromethanesulfonylimide , N-ethoxymethyl-N-methylpyrrolidinium bistrifluoromethanesulfonylimide, N-methyl-N-methoxymethylpyrrolidinium trifluoromethanesulfolate (N-methoxymethyl-N- methyltrifluoromethanesulfolate).

When used as an electrolyte, the quaternary ammonium salt can be used as mixed with a suitable organic solvent. Useful solvents include cyclic carbonic acid esters, chain carbonic acid esters, phosphoric acid esters, cyclic ethers, chain ethers, lactone compounds, chain esters, nitrile compounds, amide compounds and sulfone compounds. Although the solvent to be used is not limited to these compounds, examples of such compounds are given below.

Examples of the cyclic carbonic acid esters are ethylene carbonate, propylene carbonate, butylene carbonate and the like, of which propylene carbonate is preferred.

Examples of chain carbonic acid esters are dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate and the like, of which dimethyl carbonate and ethylmethyl carbonate are preferred.

Examples of phosphoric acid esters are trimethyl phosphate, triethyl phosphate, ethyldimethyl phosphate, diethylmethyl phosphate and the like. Examples of cyclic ethers are tetrahydrofuran, 2-methyltetrahydrofuran and the like. Examples of chain ethers are dimethoxyethane and the like. Examples of lactone compounds are γ-butyrolactone and the like. Examples of chain esters are methyl propionate, methyl acetate, ethyl acetate, methyl formate and the like. Examples of nitrile compounds are acetonitrile and the like. Examples of amide compounds are dimethylformamide and the like. Examples of sulfone compounds are sulfolane, methyl sulfolane, and the like. Cyclic carbonic acid esters, chain carbonic acid esters, nitrile compounds and sulfone compounds may be particularly preferred in some embodiments.

These solvents may be used alone or at least two kinds of solvents may be used as a mixture. Examples of preferred organic solvent mixtures are ethylene carbonate and dimethyl carbonate, ethylene carbonate and ethylmethyl carbonate, ethylene carbonate and diethyl carbonate, propylene carbonate and dimethyl carbonate, mixtures of cyclic and chain carbonic esters, such as propylene carbonate and ethylmethyl carbonate, and mixtures of propylene carbonate and diethyl carbonate, and dimethyl carbonate and ethylmethyl carbonate, etc. mixtures of chain carbonic acid esters, and mixtures of sulfolane compounds such as sulfolane and methylsulfolane. More preferred are mixtures of ethylene carbonate and ethylmethyl carbonate, propylene carbonate and ethylmethyl carbonate, and dimethyl carbonate and ethylmethyl carbonate.

In some embodiments, when the quaternary ammonium salt of the present invention is used as the electrolyte, the electrolyte concentration is at least 0.1 M, in some cases at least 0.5 M, and may be at least 1 M. If the concentration is less than 0.1 M, the electrical conductivity will be low, producing an electrochemical device with deteriorated performance. The upper limit concentration is the separation concentration when the electrolyte is a liquid salt at room temperature. When the solution does not separate, the limiting concentration is 100%. When the salt is a solid at room temperature, the limiting concentration is the concentration at which the solution is saturated with the salt.

In certain embodiments, an improved electrolyte system (AES) may be used without significantly affecting the benefits achieved by utilization of the improved electrolyte system, such as, for example, no more than 10% change in performance or durability characteristics. It may be mixed with other electrolytes than those described herein. Examples of electrolytes that may be suitable for mixing with AES are alkali metal salts, quaternary ammonium salts, quaternary phosphonium salts, and the like. These electrolytes may be used alone, or at least two of them may be used in combination as mixed with the AES disclosed herein. Useful alkali metal salts include lithium salts, sodium salts and potassium salts. Examples of such lithium salts include, but are not limited to, lithium hexafluorophosphate, lithium borofluoride, lithium perchlorate, lithium trifluoromethanesulfonate, lithium sulfonylimide, lithium sulfonylmethide, and the like. Examples of useful sodium salts are sodium hexafluorophosphate, sodium borofluoride, sodium perchlorate, sodium trifluoromethanesulfonate, sodium sulfonylimide, sodium sulfonylmethide, and the like. Examples of useful potassium salts include, but are not limited to, potassium hexafluorophosphate, potassium borofluoride, potassium perchlorate, potassium trifluoromethanesulfonate, sulfonylimide potassium, sulfonylmethide potassium, and the like.

Useful quaternary ammonium salts that can be used in the combinations described above (which do not significantly affect the benefits achieved by utilization of the improved electrolyte system) are: tetraalkylammonium salts, imidazolium salts, pyrazolium salts, pyrazolium salts dinium salts, triazolium salts, pyridazinium salts, and the like. Examples of useful tetraalkylammonium salts are tetraethylammonium tetracyanoborate, tetramethylammonium tetracyanoborate, tetrapropylammonium tetracyanoborate, tetrabutylammonium tetracyanoborate, triethylmethylammonium tetracyanoborate, Trimethylethylammonium tetracyanoborate, dimethyldiethylammonium tetracyanoborate, trimethylpropylammonium tetracyanoborate, trimethylbutylammonium tetracyanoborate, dimethylethylpropylammonium tetracyanoborate, methylethylpropylbutylammonium tetracyano Borate, N,N-dimethylpyrrolidinium tetracyanoborate, N-ethyl-N-methylpyrrolidinium tetracyanoborate, N-methyl-N-propylpyrrolidinium tetracyanoborate, N-ethyl-N -Propylpyrrolidinium tetracyanoborate, N,N-dimethylpiperidinium tetracyanoborate, N-methyl-N-ethylpiperidinium tetracyanoborate, N-methyl-N-propylpiperidinium tetracy Anoborate, N-ethyl-N-propylpiperidinium tetracyanoborate, N,N-dimethylmorpholinium tetracyanoborate, N-methyl-N-ethylmorpholinium tetracyanoborate, N-methyl- N-propylmorpholinium tetracyanoborate, N-ethyl-N-propylmorpholinium tetracyanoborate, and the like, while these examples are not limiting.

Examples of imidazolium salts that can be used in the combinations described above (which do not significantly affect the benefits achieved by the utilization of the improved electrolyte system) are 1,3-dimethylimidazolium tetracyanoborate, 1 -Ethyl-3-methylimidazolium tetracyanoborate, 1,3-diethylimidazolium tetracyanoborate, 1,2-dimethyl-3-ethylimidazolium tetracyanoborate and 1,2-dimethyl -3-propylimidazolium tetracyanoborate. Examples of pyrazolium salts are 1,2-dimethylpyrazolium tetracyanoborate, 1-methyl-2-ethylpyrazolium tetracyanoborate, 1-propyl-2-methylpyrazolium tetracyanoborate and 1-methyl -2-butylpyrazolium tetracyanoborate, but is not limited thereto. Examples of pyridinium salts are, but are not limited to, N-methylpyridinium tetracyanoborate, N-ethylpyridinium tetracyanoborate, N-propylpyridinium tetracyanoborate and N-butylpyridinium tetracyanoborate. it's not going to be Examples of triazolium salts are, but are not limited to, 1-methyltriazolium tetracyanoborate, 1-ethyltriazolium tetracyanoborate, 1-propyltriazolium tetracyanoborate and 1-butyltriazolium tetracyanoborate. it's not going to be Examples of pyridazinium salts are 1-methylpyridazinium tetracyanoborate, 1-ethylpyridazinium tetracyanoborate, 1-propylpyridazinium tetracyanoborate and 1-butylpyridazinium tetracyanoborate. However, it is not limited to these. Examples of quaternary phosphonium salts are tetraethylphosphonium tetracyanoborate, tetramethylphosphonium tetracyanoborate, tetrapropylphosphonium tetracyanoborate, tetrabutyl phosphonium tetracyanoborate, triethylmethylphosphonium Tetrafluoroborate, trimethylethylphosphonium tetracyanoborate, dimethylethylphosphonium tetracyanoborate, trimethylpropylphosphonium tetracyanoborate, trimethylbutylphosphonium tetracyanoborate, dimethylethylpropylphosphonium tetracyanoborate , methylethylpropylbutylphosphonium tetracyanoborate, but is not limited thereto.

In certain embodiments, the novel electrolytes selected herein for use in improved electrolyte systems may also be purified. Such purification may be performed using techniques known in the art or techniques provided herein. Such purification may further enhance the properties of the novel electrolyte materials disclosed herein.

ii. Highly purified electrolytes

The improved electrolyte system of the present invention, in one embodiment, includes a specific highly purified electrolyte for use in high temperature ultracapacitors. In certain embodiments. The highly purified electrolyte comprising the AES of the present invention is the above-described novel electrolyte purified by the purification process disclosed herein, as well as the electrolytes disclosed below. The purification methods provided herein can be, for example, from about 80°C to 210°C, such as from about 80°C to about 200°C, such as from about 80°C to about 190°C, such as about 80 °C to about 180 °C, such as about 80 °C to about 170 °C, such as about 80 °C to about 160 °C, such as about 80 °C to about 150 °C, such as about 85 °C to about 145 °C, such as about 90 °C to about 140 °C, such as about 95 °C to about 135 °C, such as about 100 °C to about 130 °C, such as about 105 °C to about 125 °C Produces impurity levels that provide improved electrolyte systems with improved properties for use in high temperature applications, eg, high temperature ultracapacitors, in the temperature range of °C, eg, about 110 °C to about 120 °C.

Achieving improved properties of ultracapacitors 10 results in a need for better electrolyte systems than are currently available. For example, it has been found that increasing the operating temperature range can be achieved by significant reduction/removal of impurities from certain types of known electrolytes. Impurities of particular interest are water, halide ions (chloride, bromide, fluoride, iodide), free amine (ammonia), sulfate and metal cations (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, Ti, Zn). This purified highly purified electrolyte product provides an electrolyte that is surprisingly significantly superior to the crude electrolyte and, as such, is included in the improved electrolyte system of the present invention.

In certain embodiments, the present invention provides a purified mixture of cations (9) and anions (11), in some cases containing less than about 5000 ppm chloride ions; less than about 1000 ppm fluoride ions; and/or less than about 1000 ppm moisture (eg, less than about 2000 ppm chloride ions; less than about 200 ppm fluoride ions; and/or less than about 200 ppm moisture, such as about 1000 ppm less than chloride ions; less than about 100 ppm fluoride ions; and/or less than about 100 ppm moisture, e.g., less than about 500 ppm chloride ions; less than about 50 ppm fluoride ions; and /or serve as an AES of the present invention comprising less than about 50 ppm moisture, e.g., less than about 780 ppm chloride ions; less than about 11 ppm fluoride ions; and less than about 20 ppm moisture, etc. It provides a solvent capable of

In general, impurities in a purified electrolyte are removed using the purification methods disclosed herein. For example, in some embodiments, the total concentration of halide ions (chloride, bromide, fluoride, iodide) may be reduced below about 1,000 ppm. a total concentration of metallic species (e.g., comprising at least one of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb, Zn, alloys and oxides thereof) below about 1,000 ppm can be reduced to Also, impurities from solvents and precursors used in the synthesis process can be reduced below about 1,000 ppm, for example, bromoethane, chloroethane, 1-bromobutane, 1-chlorobutane, 1- methylimidazole, ethyl acetate, methylene chloride, and the like.

In some examples, the impurity content of the ultracapacitor 10 was measured using ion selective electrodes and a Karl Fischer titration procedure, which was applied to the electrolyte 6 of the ultracapacitor 10 . In a particular embodiment, it has been found that the total halide content in ultracapacitor 10 according to the teachings herein is less than about 200 ppm halides (Cl ⁻ and F ⁻ ) and the moisture content is less than about 100 ppm.

For example, impurities can be measured using AAS (atomic absorption spectroscopy), ICPMS (inductively coupled plasma-mass spectrometry), or other techniques such as simple solubilization and electrochemical sensing of trace heavy metal oxide particulates. AAS is a spectral analysis procedure for the qualitative and quantitative determination of chemical elements that employs the absorption of light radiation (light) by free atoms in the gaseous state. This technique is used to determine the concentration of a particular element (analyte) in a sample to be analyzed. AAS can be used to determine across 70 different factors in solution or directly in solid samples. ICPMS is a type of mass spectrometry that is very sensitive and can determine the range of metals and some non-metals in sub-part per trillion concentrations. The technique is based on coupling inductively coupled plasma as a method of generating (ionization) ions with mass spectrometry as a method of separating and detecting ions. ICPMS can also monitor isotopic speciation for selected ions.

Additional techniques may be used for impurity analysis. Some of these techniques are particularly beneficial for the analysis of impurities in solid samples. Ion chromatography (IC) can be used to determine trace amounts of halide impurities in electrolyte 6 (eg, ionic liquid). One advantage of ion chromatography is that the relevant halide species can be determined in a single chromatographic assay. A Dionex AS9-HC column using an eluent comprising 20 mM NaOH and 10% (v/v) acetonitrile is an example of a device that can be used for quantification of halides from ionic liquids. A further technique is X-ray fluorescence.

X-ray fluorescence (XRF) instruments can be used to measure halide content in solid samples. In this technique, a sample to be analyzed is placed in a sample cup, which is then placed in an analyzer and irradiated with X-rays of a specific wavelength. Any halogen atoms in the sample absorb some of the X-rays and then reflect radiation with a wavelength characteristic for a given halogen. A detector in the instrument then quantifies the amount of radiation from the halogen atoms and measures the intensity of the radiation. By knowing the exposed surface area, the concentration of halogens in the sample can be determined. An additional technique for estimating impurities in solid samples is pyrolysis.

The adsorption of impurities can be effectively measured through pyrolysis and the use of a microcoulometer. Microculometers can test almost any type of material for total chlorine content. For example, a small sample (less than 10 milligrams) is injected or placed into a quartz combustion tube at a temperature ranging from about 600°C to about 1,000°C. Pure oxygen is passed through the quartz tube and any chlorine-containing components are completely burned. The resulting combustion products enter the titration cell, where chloride ions are trapped in the electrolyte solution. The electrolyte solution contains the silver ions that come out of the solution as insoluble silver chloride that readily binds with any chloride ions. The silver electrode in the titration cell electrically replaces the spent silver ions until the concentration of the silver ions returns to before the titration begins. By keeping track of the amount of current required to generate the required amount of silver, the instrument can determine how much chlorine 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 estimating impurities may be used.

The surface characterization and moisture content in the electrode 3 can be checked, for example, by infrared spectroscopy techniques. The four major absorption bands at approximately 1130, 1560, 3250 and 2300 cm ⁻¹ correspond to vC=O, vC=C (in aryl), vO-H and vC-N, respectively. By measuring the intensity and the peak position, it is possible to quantitatively identify the surface impurities in the electrode 3 .

Another technique for identifying impurities in electrolyte 6 and ultracapacitor 10 is Raman spectroscopy. This spectroscopy technique relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near-infrared, or near-ultraviolet range. Laser light interacts with molecular vibrations, phonons, or other excitations within the system, resulting in a shift in the energy of the laser photon up or down. Accordingly, this technique can be used to characterize atoms and molecules in ultracapacitor 10 . A number of variations on Raman spectroscopy can be used and shown useful for characterizing the inclusions of ultracapacitors 10 .

iii. Enhanced Electrolyte Combinations

The improved electrolyte system of the present invention, in one embodiment, is in a temperature range of -40°C to 210°C, for example, -40°C to 150°C, -30°C to 150°C, without significant degradation in performance or durability; -30°C to 140°C, -20°C to 140°C, -20°C to 130°C, -10°C to 130°C, -10°C to 120°C, 0°C to 120°C, 0°C to 110°C, 0°C to Certain improved electrolyte combinations suitable for use at 100° C., 0° C. to 90° C., 0° C. to 80° C., 0° C. to 70° C.

In general, a higher degree of durability at a given temperature can match a higher degree of voltage stability at a lower temperature. Thus, as the development of high-temperature durable AESs, together with improved electrolyte combinations, generally leads to the simultaneous development of high-voltage but low-temperature AESs, these improved electrolyte combinations disclosed herein also, at higher voltages, thus It will be useful at higher energy densities, but at lower temperatures.

In one embodiment, the present invention provides an improved electrolyte combination suitable for use in an energy storage cell, such as an ultracapacitor, comprising an ionic liquid mixed with a second ionic liquid, ions mixed with an organic solvent. A novel mixture of an ionic liquid and an electrolyte selected from the group consisting of an ionic liquid mixed with a second ionic liquid and an organic solvent:

Each ionic liquid is selected from a salt of any combination of the following cations and anions, wherein the cations are 1-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-hexyl-3-methyl the group consisting of imidazolium, 1-butyl-1-methylpiperidinium, butyltrimethylammonium, 1-butyl-1-methylpyrrolidinium, trihexyltetradecylphosphonium and 1-butyl-3-methylimidazolium is selected from; the anions are selected from the group consisting of tetrafluoroborate, bis(trifluoromethylsulfonyl)imide, tetracyanoborate and trifluoromethanesulfonate; and

Organic solvents include linear sulfones (e.g., ethyl isopropyl sulfone, ethyl isobutyl sulfone, ethyl methyl sulfone, methyl isopropyl sulfone, isopropyl isobutyl sulfone, isopropyl s-butyl sulfone, butyl isobutyl sulfone and dimethyl sulfone. ), linear carbonates (eg, ethylene carbonate, propylene carbonate and dimethyl carbonate) and acetonitrile.

For example, given the above combinations of cations and anions, each ionic liquid can be selected from the group consisting of 1-butyl-3-methylimidazolium tetrafluoroborate; 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; 1-ethyl-3-methylimidazolium tetrafluoroborate; 1-ethyl-3-methylimidazolium tetracyanoborate; 1-hexyl-3-methylimidazolium tetracyanoborate; 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide; 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate; 1-butyl-1-methylpyrrolidinium tetracyanoborate; Trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide, butyltrimethylammonium bis(trifluoromethylsulfonyl)imide phonyl)imide and 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

In certain embodiments, the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate.

In certain embodiments, the ionic liquid is 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate.

In certain embodiments, the ionic liquid is 1-ethyl-3-methylimidazolium tetracyanoborate.

In certain embodiments, the ionic liquid is 1-hexyl-3-methylimidazolium tetracyanoborate.

In certain embodiments, the ionic liquid is 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

In one embodiment, the ionic liquid is 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate.

In certain embodiments, the ionic liquid is 1-butyl-1-methylpyrrolidinium tetracyanoborate.

In certain embodiments, the ionic liquid is trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the ionic liquid is bis 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the ionic liquid is butyltrimethylammonium bis(trifluoromethylsulfonyl)imide.

In certain embodiments, the ionic liquid is 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

In certain embodiments, the organic solvent is ethyl isopropyl sulfone, ethyl isobutyl sulfone, ethyl methyl sulfone, methyl isopropyl sulfone, isopropyl isobutyl sulfone, isopropyl s-butyl sulfone, butyl isobutyl sulfone or bimethyl sulfone, selected from linear sulfones.

In certain embodiments, the organic solvent is selected from polypropylene carbonate, propylene carbonate, dimethyl carbonate, ethylene carbonate.

In certain embodiments, the organic solvent is acetonitrile.

In certain embodiments, the improved electrolyte composition is an ionic liquid with an organic solvent, wherein the organic solvent is 55%-90%, eg, 37.5%, by volume of the composition.

In certain embodiments, the improved electrolyte composition is an ionic liquid with a second ionic liquid, wherein one ionic liquid is 5%-90%, eg, 60%, by volume of the composition.

The improved electrolyte combinations of the present invention provide wider temperature range performance for individual capacitors (e.g., no significant drop in capacitance and/or no significant rise in ESR when transitioning between two temperatures, e.g., When transitioning from about +30°C to about -40°C, there is no more than a 90% decrease in capacitance and/or no increase of more than 1000% in ESR, etc.), and improved temperature endurance for individual capacitors (e.g., after a given time) The increase in capacitance at a given temperature is less than 50%, and/or the increase in ESR at a given temperature after a given time is less than 100%, and/or the leakage current at a given temperature after a given time is less than 10 A/L, e.g. For example, the capacitance reduction is less than 40% and/or the ESR increase is less than 75%, and/or the leakage current is less than 5 A/L, eg the capacitance reduction is less than 30%, and/or the ESR increase is less than 50%, and/or leakage current is less than 1 A/L). 47 a and b, 48 a and b and 49 are, respectively, the action of an ionic liquid from the above listing at 125° C., the action of 37.5% organic solvent-ionic liquid (same) v/v at 125° C., and the action of the same composition at -40°C.

Without wishing to be bound by theory, the combinations described above provide eutectic properties that affect the freezing point of an improved electrolyte system providing an ultracapacitor operating within performance and durability criteria at temperatures below -40°C.

For the novel electrolytes of the present invention as described above, in certain embodiments, an improved electrolyte system (AES) can be mixed with an electrolyte, which significantly increases the benefits that this combination achieves by utilizing an improved electrolyte system. It is assumed that there is no influence.

In certain embodiments, the improved electrolyte combinations selected herein for improved electrolyte systems may also be purified. Such purification can be performed using techniques known in the art or techniques provided herein.

B. Electrodes

The EDLC comprises at least a pair of electrodes 3 (electrodes 3 may be referred to herein as negative electrode 3 and positive electrode 3 for reference purposes only). When assembled into an ultracapacitor 10, each of the electrodes 3 provides a double charge layer at the electrolyte interface. In some embodiments, a plurality of electrodes 3 are included (eg, in some embodiments at least two pairs of electrodes 3 are included). However, for illustrative purposes only a pair of electrodes 3 is shown. Herein typically, at least one of the electrodes 3 uses a carbon-based energy storage medium 1 (as further described herein) to provide energy storage. However, for the purposes of the description herein, it is generally assumed that each of the electrodes comprises a carbon-based energy storage medium 1 .

i. current collector

Each of the electrodes 3 comprises a respective current collector 2 (also referred to as a “charge collector”). In some embodiments, the electrodes 3 are separated by a separator 5 . In general, the separator 5 is a thin-structured material (usually a sheet) used to separate the negative electrode 3 and the positive electrode 3 . The separator 5 may also be used to separate pairs of electrodes 3 . 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 consist of only the current collector 2 . The material used to provide the current collector 2 may be roughened, bi-electrode oxidized, etc. to increase its surface area. In these embodiments, the current collector 2 may be used alone as the electrode 3 . With this in mind, however, when used herein, the term "electrode 3" generally refers to the combination of the energy storage medium 1 and the current collector 2 (however, this is not limited at least for the reasons described above). not).

ii. energy storage medium

In the exemplary ultracapacitor 10 , the energy storage medium 1 is formed of carbon nanotubes. The energy storage medium 1 may include, for example, activated carbon, carbon fiber, rayon, graphene, airgel, carbon cloth, and other carbonaceous materials including a plurality of forms of carbon nanotubes. For example, a carbon material obtained by carbonization of a carbon compound is subjected to a first activation treatment to produce a carbon base material, a body formed by adding a binder to the carbon base material is produced, the formed body is carbonized, and finally a carbonized base material is formed. An activated carbon electrode can be manufactured by performing a second activation treatment on the body to produce an activated carbon electrode. Carbon fiber electrodes can be produced using, for example, a paper or cloth pre-form with large surface area carbon fiber.

In an exemplary method for producing carbon nanotubes, an apparatus for producing ordered carbon nanotube aggregates includes an apparatus for synthesizing aligned carbon nanotube aggregates on a substrate having a catalyst on a surface thereof. The apparatus comprises: a forming unit which causes an environment surrounding the catalyst to be an environment of a reducing gas, and performs a forming step of heating at least the catalyst or the reducing gas; a growth unit that causes the environment surrounding the catalyst to be an environment of the raw material gas, and performs a growth step of synthesizing the aligned carbon nanotube aggregates by heating at least the catalyst or the raw material gas; and a transfer unit that transfers at least the material from the forming unit to the growth unit. Various other methods and devices can be used to provide ordered carbon nanotube agglomerates.

In some embodiments, the material used to construct the energy storage medium 1 may include a material other than pure carbon (and various forms of carbon as presently present or devised later). That is, various types of different materials may be included in the energy storage medium 1 . More specifically, and by way of non-limiting example, at least one binder material may be used in the energy storage medium 1 , although this does not suggest or require the addition of other materials (such as binder material). In general, however, the energy storage medium 1 is formed substantially of carbon, and thus may be referred to herein as a “carbonaceous material”, as a “carbonaceous layer” and other similar terms. In summary, the energy storage medium 1 is mainly composed of carbon, but any form of carbon (also any additives or impurities as deemed suitable or acceptable) to provide the necessary function as the energy storage medium 1 . ) may be included.

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

The carbonaceous material may include other forms of carbon including carbon black, graphite, and the like. The carbonaceous material may include carbon particles, such as nanotubes, nanorods, graphene sheets in the form of sheets, and/or including nanoparticles formed into cones, rods, spheres (buckyballs), etc. .

Several embodiments of various types of carbonaceous material suitable for use in the energy storage medium 1 are provided herein by way of example. These embodiments provide reliable energy storage and are suitable for use in electrode 3 . It should be noted that these examples are illustrative and do not limit embodiments of carbonaceous material suitable for use in the energy storage medium 1 .

In certain embodiments, the porosity of the energy storage medium 1 of each electrode may be selected based on the size of each electrolyte to improve the performance of the capacitor.

An exemplary process for providing an energy storage medium 1 with a current collector 2 for providing an electrode 3 is now provided. Referring to FIG. 2 , a substrate 14 made of a carbonaceous material in the form of a carbon nanotube aggregate (CNT) is shown. In the illustrated embodiment, the substrate 14 includes a substrate 17 , on which a thin layer of catalyst 18 is disposed.

In general, the substrate 14 is flexible at least to some extent (ie, the substrate 14 is not brittle) and capable of withstanding the environments for the deposition of the energy storage medium 1 (eg, CNT). manufactured from components. For example, the 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 the substrate 14 as determined appropriate.

Reference is now made to FIG. 3 . Once the energy storage medium 1 (eg, CNTs) is fabricated on the substrate 14 , the current collector 2 may be disposed thereon. In some embodiments, the current collector 2 has a thickness of about 0.5 micrometers (μm) to about 25 micrometers (μm). In some embodiments, the current collector 2 has a thickness of from about 20 micrometers (μm) to about 40 microculometers (μm). The current collector 2 may appear as a thin layer, such as a layer applied by chemical vapor deposition (CVD), sputtering, electron beam, thermal evaporation, or other suitable technique. In general, the current collector 2 is selected for its properties, such as conductivity, electrochemical inertness, and compatibility with the energy storage medium 1 (eg, CNT). Some exemplary materials include aluminum, platinum, gold, tantalum, titanium, and may include various materials, as well as various alloys.

Once the current collector 2 is disposed on the energy storage medium 1 (eg CNT), the electrode element 15 is realized. Each electrode element 15 can be used individually as an electrode 3 , or can be coupled to at least another electrode element 15 to provide an electrode 3 .

If the current collector 2 is manufactured according to a desired standard, post-production processing may be performed. Exemplary post-treatments include heating and cooling the energy storage medium 1 (eg, CNTs) in a mildly oxidizing environment. Following fabrication (and optional post-processing), a transfer tool may be applied to the current collector 2 . See FIG. 4 .

4 shows the application of the transfer tool 13 to the current collector 2 . In this example, the transfer tool 13 is a thermal release tape used in the "dry" transfer method. Exemplary thermal release tapes are manufactured by NITTO DENKO CORPORATION of Fremond, CA and Osaka, Japan. One suitable transfer tape is sold as REVALPHA. These release tapes can be characterized as adhesive tapes that adhere firmly at room temperature and can be peeled off by heating. This tape, and other suitable embodiments of the thermal release tape, will release at a predetermined temperature. Advantageously, the release tape leaves no chemically active residue on the electrode element 15 .

Another process, referred to as a “wet” transfer method, may use tapes designed for chemical release. Once applied, the tape is removed by immersion in a solvent. The solvent is designed to dissolve the adhesive.

In other embodiments, the transfer tool 13 uses a “compressed air” method, such as by application of suction to the current collector 2 . The suction may be applied, for example, via a slightly oversized paddle with a plurality of apertures for dispersing the suction. In another example, the suction is applied through a roller having a plurality of apertures for dispersing the suction. Suction actuation embodiments provide an electrically controlled advantage and an economic advantage as no consumables are used as part of the delivery process. Other embodiments of the transfer tool 13 may be used.

Once the transfer tool 13 is temporarily coupled to the current collector 2 , the electrode element 15 is properly removed from the substrate 14 (see FIGS. 4 and 5 ). Removal generally begins at one edge of the substrate 14 and the energy storage medium 1 (eg, CNTs), followed by peeling the energy storage medium 1 (eg, CNTs) from the substrate 14 . include

The transfer tool 13 can then be separated from the electrode element 15 (see FIG. 6 ). In some embodiments, the transfer tool 13 is used to install the electrode element 15 . For example, the transfer tool 13 can be used to place the electrode element 15 on the separator 5 . In general, once removed from the substrate 14, the electrode element 15 is ready for use.

In examples where a large electrode 3 is desired, a plurality of electrode elements 15 can be matched. See FIG. 7 . As shown in FIG. 7 , the plurality of electrode elements 15 may be matched, for example by matching the coupling 52 to each electrode element 15 of the plurality of electrode elements 15 . The matched electrode elements 15 provide an embodiment of the electrode 3 .

In some embodiments, the coupling 22 is coupled to each of the electrode elements 15 at the weld 21 . Each of the welds 21 may be provided as an ultrasonic weld 21 . Ultrasonic welding techniques have been found to be particularly suitable for providing each weld 21 . That is, in general, agglomerates of energy storage medium 1 (eg, CNTs) are not compatible with welding, and only nominal current collectors as disclosed herein are used. Consequently, many techniques for joining electrode elements 15 are destructive and damage element 15 . However, in other embodiments other types of couplings are used, and the coupling 22 is not the weld 21 .

The coupling 22 may be in the form of a foil, a mesh, a plurality of wires, or other forms. In general, the coupling 22 is selected for properties such as conductivity and electrochemical inertness. In some embodiments, coupling 22 is made of the same material(s) as present in current collector 2 .

In some embodiments, the coupling 22 is fabricated by removing the oxide layer thereon. The oxide may be removed, for example, by etching the coupling 22 prior to providing the weld 21 . Etching can be accomplished using, for example, potassium hydroxide (KOH). Electrode 3 may be used in other embodiments of ultracapacitor 10 . For example, the electrode 3 may be wound into an energy storage device of a “jelly roll” type.

C. Separator

The separation membrane 5 may be made of various materials. In some embodiments, the separator 5 is a non-woven glass. Separator 5 may also be made of fiberglass, ceramic, and fluoro-polymers such as polytetrafluoroethylene (PTFE) sold generally as TEFLON ^™ by DuPont Chemicals of Wilmington, Delaware. For example, when using non-woven glass, the separator 5 may include primary fibers and binder fibers, each of which has a fiber diameter smaller than the diameter of each of the primary fibers, and the primary fibers can be joined together.

For a long lifespan of the ultracapacitor 10 and to ensure its performance at high temperatures, the separator 5 must contain a reduced amount of impurities, in particular a very limited amount of moisture therein. Specifically, it has been found desirable to limit moisture to about 200 ppm in order to reduce chemical reaction and improve the lifetime of the ultracapacitor 10 and to provide good performance in high temperature applications. Some embodiments of materials for use in the separator 5 include polyamide, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), aluminum oxide (Al ₂ O ₃ ), fiberglass and glass-reinforced plastics ( GRP).

In general, materials used for the separator 5 are selected according to moisture content, porosity, melting point, impurity content, resulting electrical performance, thickness, cost, availability, and the like. In some embodiments, the separator 5 is made of hydrophobic materials.

Accordingly, procedures to ensure that excess moisture is removed from each separator 5 may be used. Among other techniques, a vacuum drying procedure may be used. A selection of materials for use in the separator 5 is provided in Table 1. Some relevant performance data is provided in Table 2.

To collect data for Table 2, two electrodes 3 based on carbonaceous material were provided. The electrodes 3 are disposed opposite to each other. Each of the separators 5 was disposed between the electrodes 3 to prevent a short circuit. The three components were then wetted with electrolyte (6) and pressed together. Two aluminum bars and a PTFE material were used as the outer structure to enclose the resulting ultracapacitor 10 .

The ESR primary test and the ESR secondary test were performed one by one using the same configuration. The second test was done 5 minutes after the first test was finished, giving more time for the electrolyte 6 to permeate into the components.

In certain embodiments, ultracapacitor 10 does not include separator 5 . For example, in some embodiments, it is sufficient to have only the electrolyte 6 between the electrodes 3 , for example if the electrodes 3 are guaranteed to be physically separated by the geometry of the construction. More specifically, as an example of physical separation, one such ultracapacitor 10 may include electrodes 3 disposed within a housing such that separation is continuously ensured. A bench-top example would include an ultracapacitor 10 provided in a beaker.

D. Storage cell

When assembled, the electrodes 3 and the separator 5 provide a storage cell 12 . Generally, the storage cell 12 is packaged in a cylindrical or prismatic housing 7 after being configured in either a rolled or prismatic form. If the electrolyte 6 is included, the housing 7 can be hermetically sealed. In other examples, the package is hermetically sealed by techniques using laser, ultrasonic and/or welding techniques. In addition to providing robust physical protection of the storage cell 12 , the housing 7 is configured to have external contacts for providing electrical communication with respective terminals 8 within the housing 7 . Each of the terminals 8 also generally provides electrical access to energy stored in the energy storage medium 1 via electrical leads coupled to the energy storage medium 1 .

In general, the ultracapacitor 10 disclosed herein can provide a hermetic seal having a leak rate of about 5.0x10 ^-6 atm-cc/sec or less, and about 5.0x10 ^-10 atm-cc/sec or less. leak rate can be seen. Where appropriate, the performance of a successful hermetic seal is judged by the user, designer, or manufacturer, and it is also contemplated that "confidential" implies a standard ultimately defined by the user, designer, manufacturer, or other person concerned.

Leak detection may be accomplished, for example, by use of a tracer gas. Using a tracer gas such as helium for leak testing is advantageous because 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 exposed 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 monitoring the presence of helium. Using knowledge of pressurization time, pressure, and internal volume, the leak rate of the ultracapacitor 10 can be determined.

In some embodiments, at least one lead (which may also be referred to herein as a “tab”) is electrically coupled to each of the current collectors 2 . A plurality of leads may be grouped together (according to the polarity of the ultracapacitor 10 ) and coupled to the respective terminals 8 . In addition, terminal 8 is a "contact" (eg, housing 7 and an external electrode (also commonly referred to herein as "feed-through" or "pin")) one) to an electrical access. 28 and 32-34 may be referred to.

E. Housing

11 depicts faces of an exemplary housing 7 . In particular, the housing 7 provides structural and physical protection for the ultracapacitor 10 . In this example, the housing 7 comprises an annular cylindrical body 20 and a complementary cap 24 . In this embodiment, cap 24 includes a central portion that is removed and filled with electrical insulator 26 . A cap feed-through 19 passes through the electrical insulator 26 to provide users with access to the stored energy. Moreover, the housing may also include an inner barrier 30 .

Although this example shows only one feed-through 19 on the cap 24 , it should be appreciated that the construction of the housing 7 is not limited by the embodiments discussed herein. For example, the cap 24 may include a plurality of feed-throughs 19 . In some embodiments, the body 20 includes a second similar cap 24 at opposite ends of the annular cylinder. It should also be appreciated that the housing 7 is not limited to embodiments having an annular cylindrical body 20 . For example, the housing 7 may be of a capped design, a prismatic design, a pouch, or any other design suitable to the needs of the designer, manufacturer or user.

Referring now to FIG. 12 , an exemplary energy storage cell 12 is shown. In this example, the energy storage cell 12 is a “jellyroll” type of energy storage. In these embodiments, the energy storage materials are rolled up into a tight package. A plurality of leads generally constitutes each terminal 8 and provides electrical access to the appropriate layer of the energy storage cell 12 . In general, when assembled, each terminal 8 is electrically coupled to the housing 7 (eg to the respective feed-through 19 and/or directly to the housing 7 ). The energy storage cell 12 may assume other forms. There are generally at least two pluralities of leads (eg terminals 8 ), one for each current collector 2 . For simplicity, only one terminal 8 is shown in FIGS. 12 , 15 and 17 .

A very efficient sealing of the housing 7 is desired. That is, preventing intrusion of the external environment (eg, air, moisture, etc.) helps maintain the purity of the components of the energy storage cell 12 . Also, this prevents leakage of the electrolyte 6 from the energy storage cell 12 .

In this example, the cap 24 is manufactured to have an outer diameter that is designed to fit comfortably within the inner diameter of the body 20 . When assembled, the cap 24 may be welded into the body 20 , thus providing a hermetic seal to users. Exemplary welding techniques include laser welding and TIG welding, and may include other types of welding as deemed suitable.

Common materials for housing 7 include stainless steel, aluminum, tantalum, titanium, nickel, copper, tin, other alloys, laminates, and the like. Structural materials such as some polymer based materials (generally in combination with at least some metal components) may be used for the housing 7 .

In some embodiments, the material used to construct the body 20 includes aluminum, which may include any type of aluminum or aluminum alloy deemed suitable by the designer or manufacturer (all of which are incorporated herein by reference). broadly simply referred to as "aluminum"). Various alloys, laminates, etc. may be disposed (eg, cladded) on aluminum (aluminum exposed to the interior of body 20 ). Additional materials (such as some polymer-based materials, electrically insulating materials or structural materials) may be used to complement the body and/or housing 7 . The material disposed on the aluminum may likewise be selected as deemed appropriate by the designer or manufacturer.

In some embodiments, a multilayer material is used for the interior components. For example, aluminum may be clad with stainless steel to provide a multilayer material for at least one of the terminals 8 . In some of these embodiments, some of the aluminum may be removed to expose the stainless steel. The exposed stainless steel can then be used to attach the terminal 8 to the feed-through 19 by use of simple welding procedures.

The use of a clad material for internal components may require specific embodiments of the clad material. For example, using a clad material comprising aluminum (bottom layer), stainless steel and/or tantalum (middle layer) and aluminum (top layer), thereby introducing stainless steel into the internal environment of the ultracapacitor 10 . It may be beneficial to limit exposure of These embodiments may be augmented by an additional coating with polymeric materials such as, for example, PTFE.

Accordingly, providing a housing 7 using a multilayer material provides for energy storage exhibiting a leakage current having relatively low initial values and a substantially slower increase in leakage current over time by prior art standards. Significantly, the leakage current of the ultracapacitor 10 is determined by exposure of the ultracapacitor to ambient temperature at which prior art capacitors exhibit leakage currents of extremely large initial values and/or increase leakage current very rapidly over time. maintained at a realistic (ie, preferably low) level.

In addition, the ultracapacitor 10 may exhibit other advantages as a result of reduced reaction between the housing 7 and the energy storage cell 12 . For example, the effective series resistance (ESR) of an energy storage can exhibit relatively low values over time. In addition, unwanted chemical reactions that occur in conventional capacitors often cause undesirable effects such as out-gassing or, in the case of hermetically sealed housings, bulging of the housing 7 . In both cases, this results in damage to the structural integrity of the hermetic seal of the housing 7 and/or of the energy storage. Ultimately, this can lead to leaks or catastrophic failures for conventional capacitors. These effects can be substantially reduced or eliminated by application of the disclosed barriers.

Using a multi-layer material (eg, a clad material), stainless steel can be integrated into the housing 7 , so that a component with a glass-to-metal seal can be used. The component 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 another aluminum part (eg, body 20 ).

In some embodiments, an insulating polymer may be used to coat portions of the housing 7 . In this way, it can be ensured that only the components of the energy storage are exposed to acceptable metal types (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 each material. Referring to FIG. 23 , a small amount of insulating material 39 is included to limit the exposure of the electrolyte 6 to the stainless steel sleeve 51 and the feed-through 19 . In this example, the terminal 8 is coupled to the feed-through 19 , for example by welding, and then coated with an insulating material 39 .

i. housing cap

Although this example shows only one feed-through 19 on the cap 24 , it should be appreciated that the configuration of the housing 7 is not limited by the embodiments discussed herein. For example, the cap 24 may include a plurality of feed-throughs 19 . In some embodiments, the body 20 includes a second similar cap 24 at opposite ends of the annular cylinder. It should also be appreciated that the housing 7 is not limited to embodiments having an annular cylindrical body 20 . For example, the housing 7 may be of a capped design, a prismatic design, a pouch, or any other design suitable to the needs of the designer, manufacturer or user.

Referring now to FIG. 18 , aspects of embodiments of a blank 34 for a cap 24 are shown. In Figure 18A, blank 34 comprises a multi-layered material. The layer 41 of the first material may be aluminum. Layer 42 of the second material may be stainless steel. In the embodiments of Figure 18, stainless steel is clad to aluminum, thus providing a material that exhibits a desired combination of metallurgical properties. That is, in the embodiments provided herein, the aluminum is exposed to the inside of the energy storage cell (ie, the housing), while the stainless steel is exposed to the outside. In this way, while enjoying the advantageous electrical properties of aluminum, it relies on the structural properties (and metallurgical properties, ie weldability) of stainless steel for construction. The multilayer material may include additional layers deemed suitable.

As mentioned above, a layer 41 of a first material is clad (or layered) to a layer 42 of a second material. Still referring to FIG. 18A , in one embodiment, a blank 34 is provided using a sheet of flat stock (as shown) to create a flat cap 24 . A portion of the layer 42 of the second material (such as around the circumference of the cap 24 ) may be removed to facilitate attachment of the cap 24 to the body 20 . 18b , another embodiment of a blank 34 is shown. In this example, the blank 34 is provided as a sheet of clad material formed in a concave configuration. In Fig. 18C, the blank 34 is provided as a sheet of clad material formed in a convex configuration. A cap 24 made from other embodiments of the blank 34 (such as those shown in FIG. 18 ) is configured to support the welding of the housing 7 to the body 20 . More specifically, the embodiment of FIG. 18B is configured to fit within an inner diameter of the body 20 , and the embodiment of FIG. 18C is configured to fit an outer diameter of the body 20 . In other alternative embodiments, the layers of clad material in the sheet may be reversed.

Referring now to FIG. 19 , an embodiment of an electrode assembly 50 is shown. The electrode assembly 50 is installed in the blank 34 and is designed to provide a user with electrical communication from the energy storage medium. Generally, the electrode assembly 50 includes a sleeve 51 . The sleeve 51 surrounds the insulator 26 surrounding the feed-through 19 . In this example, sleeve 51 is an annular cylinder having a flanged top portion.

To assemble the cap 24 , perforations (not shown) are made in the blank 34 . The perforations have a geometry that is sized to fit the electrode assembly 50 . Thus, the electrode assembly 50 is inserted into the perforations of the blank 34 . Once the electrode assembly 50 is inserted, the electrode assembly 50 may be fixed to the blank 34 through a technique such as welding. The welding may be laser welding welding about the circumference of the flange of the sleeve 51 . Referring to FIG. 20 , points 61 are shown where welding has been performed. In this embodiment, points 61 provide suitable locations for welding of stainless steel to stainless steel, which is a relatively simple welding procedure. Accordingly, the teachings herein provide for safely welding the electrode assembly 50 in place on the blank 34 .

The material for constructing the sleeve 51 may include other types of metals or metal alloys. In general, the material for the sleeve 51 is selected according to, for example, structural integrity and bondability (to the blank 34 ). Exemplary materials for sleeve 51 include 304 stainless steel or 316 stainless steel. The material for constructing the feed-through 19 may include other types of metals or metal alloys. In general, the material for the feed-through 19 is selected according to, for example, structural integrity and electrical conductivity. Exemplary materials for the electrode include 446 stainless steel or 52 alloy.

Insulator 26 is generally coupled to sleeve 51 and feed-through 19 via known techniques (ie, glass-to-metal bonding). The material for constructing the insulator 26 may include, but is not limited to, high temperature glass, ceramic glass, or other types of glass including ceramic materials. In general, materials for insulators are selected according to, for example, structural integrity and electrical resistivity (ie, electrical insulating properties).

The use of various welding techniques, as well as the use of components that rely on glass-to-metal bonding (eg, the aforementioned embodiment of electrode assembly 50 ) provide a hermetic seal of energy storage. Other components may also be used to provide a hermetic seal. As used herein, the term “hermetic seal” generally refers to a seal exhibiting a leak rate not greater than that defined herein. However, it is contemplated that actual sealing efficiencies may perform better than these standards.

Additional or other techniques for coupling the electrode assembly 50 to the blank 34 are provided under the flange of the sleeve 51 (between the flange and the layer 42 of second material) when such techniques are deemed appropriate. e) the use of binders.

Referring now to FIG. 21 , the energy storage cell 12 is disposed within the body 20 . At least one terminal 8 is suitably coupled (eg, to the feed-through 19 ), and a cap 24 is matched with the body 20 to provide the ultracapacitor 10 .

Once assembled, cap 24 and body 20 may be sealed. 22 shows other embodiments of assembled energy storage (in this case, ultracapacitor 10 ). In FIG. 22A , a flat blank 34 (see FIG. 18A ) is used to create a flat cap 24 . Once the cap 24 is installed on the body 20 , the cap 24 and the body 20 are welded to create a seal 62 . In this case, since the body 20 is an annular cylinder, the welding proceeds circumferentially with respect to the cap 24 and the body 20 to provide a seal 62 . In the second embodiment shown in Fig. 22b, a concave cap 24 is created using a concave blank 34 (see Fig. 18b). Once the cap 24 is installed on the body 20 , the cap 24 and the body 20 are welded to create a seal 62 . In the third embodiment shown in FIG. 22C , the convex cap 24 is produced using a convex blank 34 (see FIG. 18C ). Once the cap 24 is installed on the body 20 , the cap 24 and the body 20 may be welded to create a seal 62 .

Suitably, the clad material may be removed (eg, by techniques such as machining or etching) to expose other metals in the multilayer material. Accordingly, in some embodiments, the seal 62 may include an aluminum-to-aluminum weld. Aluminum to aluminum welding may be supplemented with other fasteners as appropriate.

Other techniques may be used to seal the housing 7 . For example, laser welding, TIG welding, resistance welding, ultrasonic welding, and other types of mechanical sealing may be used. However, it should be noted that, in general, conventional forms of mechanical sealing alone are not sufficient to provide the robust hermetic seal provided for the ultracapacitor 10 .

Referring now to FIG. 24 , an assembly side view of another embodiment for a cap 24 is shown. 24A shows a template (ie, blank 34 ) used to provide the body of cap 24 . The template is generally sized to match a housing 7 of an appropriate type of energy storage cell (such as ultracapacitor 10). The cap 24 initially constructs a template comprising a dome 37 within the template to provide the template (shown in FIG. 24B ) and then perforates the dome 37 to form a through-way 32 . ) (shown in Figure 24c). Of course, the blank 34 (eg, a circular piece of stock) may be pressed or otherwise manufactured such that the aforementioned features are provided simultaneously.

Generally, with respect to this embodiment, the cap may be constructed of aluminum, or an alloy thereof. However, the cap may be constructed of any material deemed suitable by the manufacturer, user, designer, or the like. For example, cap 24 may be made of steel and passivated (ie coated with an inert coating) or otherwise manufactured for use in housing 7 .

Also, referring now to FIG. 25 , another embodiment of an electrode assembly 50 is shown. In this embodiment, the electrode assembly 50 includes a feed-through 19 and a hemispherical material disposed about the feed-through 19 . The hemispherical material serves as the insulator 26 , and is generally shaped to fit the dome 37 . The hemispherical insulator 26 may be made of any suitable material to provide a hermetic seal while withstanding the chemical effects of the electrolyte 6 . Exemplary materials include PFA (perfluoroalkoxy polymer), FEP (fluorinated ethylene-propylene), PVF (polyvinylfluoride), TFE (tetrafluoroethylene), CTFE (chlorotrifluoroethylene), PCTFE (polychlorotrifluoroethylene), ETFE (polyethylenetetrafluoroethylene), ECTFE (polyethylenechlorotrifluoroethylene), PTFE (polytetrafluoroethylene), as well as other fluoropolymer-based materials (in various ways ) and capable of providing satisfactory performance (eg, by exhibiting high resistance to solvents, acids and bases, low cost, etc., at high temperatures, among others) and similar properties.

The feed-through 19 may be made of aluminum, or an alloy thereof. However, the feed-through 19 may be constructed of any material deemed suitable by the manufacturer, user, designer, or the like. For example, feed-through 19 may be made of steel and passivated (ie coated with an inert coating such as silicon) or otherwise manufactured for use in electrode assembly 50 . An exemplary technique for passivation involves depositing a coating of hydrogenated amorphous silicon on the surface of a 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 for an effective length of time. include The hydrogenated amorphous silicon coating is deposited by exposing the substrate to a silicon hydride gas under pressure and elevated temperature for an effective length of time.

The hemispherical insulator 26 can be sized according to the dome 37 to achieve a snug fit (ie, a hermetic seal) when assembled to the cap 24 . The hemispherical insulator 26 need not be perfectly symmetrical or of typical hemispherical proportions. That is, the hemispherical insulator 26 is substantially hemispherical and may include, for example, some adjustments in proportion, a modest flange (eg, at the base), and other features deemed appropriate. The hemispherical insulator 26 is generally composed of a homogeneous material, although 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.

As shown in FIG. 26 , an electrode assembly 50 may be inserted into a template (ie, constructed blank 34 ) to provide one embodiment for a cap 24 comprising a hemispherical hermetic seal.

27 , in another embodiment, a retainer 43 faces the bottom of the cap 24 (ie, faces the interior of the housing 7 and faces the energy storage cell 12 ) part of the cap 24) that is coupled or otherwise matched. The retainer 43 may be coupled to the cap 24 via other techniques such as aluminum welding (such as laser, ultrasonic, etc.). Other techniques may be used for bonding, including, for example, stamping (ie, mechanical bonding) and brazing. The engagement may occur, for example, along the perimeter of the retainer 43 . In general, engagement is provided at at least one engagement point to create 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 .

In the example of FIG. 27 , the cap 24 is of a concave design (see FIG. 18B ). However, other designs may be used. For example, a convex cap 24 may be provided ( FIG. 18C ), and an over-cap 24 may also be used (a variant of the embodiment of FIG. 18C , configured to mount as shown in FIG. 22C ).

The material used for the cap as well as the feed-through 19 may be selected with regard to the thermal expansion of the hemispherical insulator 26 . In addition, manufacturing techniques can also be devised to account for thermal expansion. For example, when assembling the cap 24 , the manufacturer may apply pressure to the hemispherical insulator 26 , thereby compressing the hemispherical insulator 26 at least to some extent. In this way, at least some thermal expansion of the cap 24 is provided without jeopardizing the effectiveness of the hermetic seal.

For further refinement of the assembled ultracapacitor, referring to FIG. 28 , a cut-away of the ultracapacitor 10 is provided. In this example, a storage cell 12 is inserted and contained within the body 20 . Each of the plurality of leads is tied together and coupled to the housing 7 as one of the terminals 8 . In some embodiments, the plurality of leads are coupled to the bottom of the body 20 , thereby turning the body 20 into a negative contact 55 . Similarly, another plurality of leads are bundled and coupled to the feed-through 19 , providing a positive contact 56 . Electrical insulation of the negative contact 55 and the positive contact 56 is preserved by the electrical insulator 26 . Typically, coupling of the leads is achieved through welding, such as at least one of laser and ultrasonic welding. Of course, other techniques considered suitable may be used.

ii. internal barrier

Referring now to FIG. 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 of polytetrafluoroethylene (PTFE). Polytetrafluoroethylene (PTFE) exhibits other properties that this construction makes to fit the barrier 30 . PTFE has a melting point of about 327° C., excellent dielectric properties, a third lowest coefficient of friction of about 0.05 to 0.10 among any known solid materials, high corrosion resistance, and other beneficial properties. In general, the interior of the cap 24 may include a barrier 30 disposed thereon.

Other materials may be used for the barrier 30 . In particular other materials are in the form of ceramics (any type of ceramic that can be applied properly and meet performance criteria), other polymers (preferably high temperature polymers), and the like. Exemplary other polymers include perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP) as well as ethylene tetrafluoroethylene (ETFE).

The barrier 30 may include any material or combinations of materials that provide for the reduction of electrochemical or other types of reactions between the energy storage cell 12 and the housing 7 or components of the housing 7 . can In some embodiments, the combinations appear as homogeneous dispersions of different materials within a single layer. In other embodiments, the combinations appear as different materials in the multilayer. Other combinations may be used. In summary, the barrier 30 can be considered as at least one of an electrical insulator and a chemically inert (ie, exhibiting low reactivity), thus preventing electrical and chemical interactions between the storage cell 12 and the housing 7 . may substantially resist or interfere with at least one of In some embodiments, the terms “low reactivity” and “low chemical reactivity” refer to a proportion of chemical interactions that are generally below the level of interest to a stakeholder.

In general, the interior of the housing 7 may be hosted on the barrier 30 such that all surfaces of the housing 7 exposed therein are covered. At least one untreated region 31 may be included in the body 20 and on the outer surface 36 of the cap 24 (see FIG. 14A ). In some embodiments, untreated regions 31 (see FIG. 14B ) may be included to account for assembly requirements, such as regions to be sealed or connected (eg, by welding).

Barrier 30 may be applied to the interior portions using conventional techniques. For example, in the case of PTFE, the barrier 30 may be applied as a coating by painting or spraying the barrier 30 onto the inner surface. A mask may be used as part of the process to ensure that the untreated region 31 maintains the desired integrity. In summary, other techniques may be used to provide the barrier 30 .

In an exemplary embodiment, the barrier 30 is about 3 mils to about 5 mils thick, and the material used for the barrier 30 is a PFA based material. In this example, the surface receiving the material constituting the barrier 30 is made by grit blasting, such as aluminum oxide. Once the surface is cleaned, the material is applied first as a liquid and then as a powder. The material is cured by a heat treatment process. In some embodiments, the heating cycle has a duration of from about 10 minutes to about 15 minutes at a temperature of about 370°C. This results in a continuous finish for the barrier 30 that is substantially free of pin-hole size or smaller defects. 15 shows an assembly of an embodiment of an ultracapacitor 10 in accordance with the teachings herein. In this embodiment, the ultracapacitor 10 comprises a body 20 including a barrier 30 disposed therein, a cap 24 having a barrier 30 disposed therein, and an energy storage cell 12 . include During assembly, the cap 24 is installed over the body 20 . A first of the terminals (8) is electrically coupled to the cap feed-through (19), and a second of the terminals (8) is typically at the bottom, on the side, or in the cap (24) of the housing (7) is electrically coupled. In some embodiments, a second of the terminals 8 is coupled to another feed-through 19 (eg, of the opposing cap 24 ).

By means of the barrier 30 disposed on the inner surface(s) of the housing 7 , electrochemical reactions and other reactions between the housing 7 and the electrolyte may be greatly reduced or substantially eliminated. This is particularly noticeable at higher temperatures, where the rates of chemical and other reactions generally increase.

Referring now to FIG. 16 , the relative performance of ultracapacitor 10 compared to other equivalent ultracapacitors is shown. In FIG. 16A , the leakage current for a prior art embodiment of an ultracapacitor 10 is shown. In FIG. 16B , the leakage current for an equivalent ultracapacitor 10 including a barrier 30 is shown. In Fig. 16B, the ultracapacitor 10 is electrically equivalent to the ultracapacitor shown in Fig. 16A with leakage current. In both cases, the housing 7 was stainless steel, the voltage supplied to the cell was 1.75 Volts, and the electrolyte was not purified. The temperature was maintained at a constant 150°C. In particular, the leakage current of FIG. 16B exhibits a relatively lower initial value, no substantial increase over time, and the leakage current of FIG. 16A exhibits a relatively higher initial value as well as a significant increase over time.

In general, the barrier 30 provides suitable materials of suitable thickness between the energy storage cell 12 and the housing 7 . The barrier 30 may comprise a homogeneous mixture, a heterogeneous mixture and/or at least one layer of material. Barrier 30 may provide full coverage (ie, providing coverage to the interior surface area of the housing excluding electrode contacts) or partial coverage. In some embodiments, barrier 30 is comprised of multiple components. For example, consider the embodiment provided below and shown in FIG. 8 .

Referring to FIG. 17 , aspects of a further embodiment are illustrated. In some embodiments, energy storage cells 12 are stacked within envelope 73 . That is, once assembled, the energy storage cell 12 has a barrier 30 disposed thereon, enclosed thereon, or otherwise applied to separate the energy storage cell 12 from the housing 7 . The envelope 73 may be applied prior to packaging the energy storage cell 12 into the housing 7 . Accordingly, the use of the envelope 73 may provide certain advantages, for example, to manufacturers. (Note that the envelope 73 is shown loosely disposed on the energy storage cell 12 for illustrative purposes.)

In some embodiments, the envelope 73 is used in combination with a coating, the coating being disposed on at least a portion of the interior surface. For example, in one embodiment, the coating is disposed on the interior of the housing 7 only in areas where the envelope 73 can be at least partially compromised (such as the protruding terminal 8 ). In addition, the envelope 73 and the coating constitute an effective barrier 30 .

Thus, the incorporation of the barrier 30 can provide an ultracapacitor that exhibits a leakage current having relatively low initial values by prior art standards and a substantially slower increase in leakage current over time. Significantly, the leakage current of an ultracapacitor is a realistic (i.e., , preferably kept at a low) level.

Having thus described embodiments of the barrier 30 and other aspects thereof, it is recognized that the ultracapacitor 10 may exhibit other benefits as a result of reduced reaction between the housing 7 and the energy storage medium 1 . Should be. For example, the effective series resistance (ESR) of the ultracapacitor 10 may exhibit relatively lower values over time. In addition, the unwanted chemical reactions that occur in prior art capacitors often produce undesirable effects such as outgassing, or bulging of the housing in the case of hermetically sealed housings. In both cases, this leads to a violation of the hermetic sealing of the capacitor and/or the structural integrity of the housing. Ultimately, this can lead to leaks or catastrophic failures for conventional capacitors. In some embodiments, these effects may be substantially reduced or eliminated by application of the disclosed barrier 30 .

It should be noted 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 24 may be used. For example, in other embodiments, the barrier 30 is actually made into or on a material constituting the housing body 20 , the material then forming the other components of the housing 7 . It is acted or molded appropriately for Given some of the many possible techniques for applying the barrier 30, it may be equally appropriate to apply the material(s) on a roll on, sputter, sinter, laminate, print, or otherwise. . In summary, barrier 30 may be applied by a manufacturer, designer, and/or user using any technique deemed suitable.

The materials used for the barrier 30 may be selected according to properties such as reactivity, dielectric value, melting point, adhesion to the materials of housing 7, coefficient of friction, cost, and other such factors. Combinations of materials (eg, layered, mixed, or otherwise combined) can be used to provide the desired properties.

The use of an improved housing 7 , such as with a barrier 30 , may, in some embodiments, limit electrolyte degradation. The barrier 30 provides one technique for providing the improved housing 7 , although other techniques may be used. For example, the use of a housing 7 made of aluminum would be beneficial due to the electrochemical properties of aluminum in the presence of the electrolyte 6 . However, considering the difficulties in the production of aluminum, it has not been (so far) possible to construct embodiments of the housing 7 using aluminum.

Additional embodiments of the housing 7 include those that provide aluminum on all interior surfaces that may be exposed to the electrolyte, while providing users with the ability to weld and hermetically seal the housing. An improved performance ultracapacitor 10 may be realized by reducing internal corrosion, eliminating problems associated with the use of dissimilar metals in conductive media, and for other reasons. Advantageously, the housing 7 is made available with conventional technology, such as electrode inserts, which include glass-to-metal seals (and may include those made from stainless steel, tantalum or other beneficial materials and components). is used, which is economical to manufacture.

Although disclosed herein as embodiments of a housing 7 suitable for an ultracapacitor 10, these embodiments (with a barrier 30) may be used with any type of energy storage that appears suitable; It may include any type of technology feasible. Other forms of energy storage may be used, including, for example, electrochemical batteries, particularly lithium-based batteries.

In general, the material(s) exposed on the inside of the housing 7 exhibit a sufficiently low reactivity when exposed to the electrolyte 6 , and thus are merely illustrative of some of the embodiments and are not limiting of the teachings herein. .

F. Factors for the general construction of capacitors

An important aspect to consider in the construction of the ultracapacitor 10 is maintaining good chemical hygiene. To ensure the purity of the components, in another embodiment, activated carbon, carbon fiber, rayon, carbon cloth and/or nanotubes constituting the energy storage medium 1 for the two electrodes 3 are placed in a vacuum environment. dried at elevated temperature. The separation membrane 5 is also dried at an elevated temperature in a vacuum environment. Once the electrodes 3 and separator 5 are dried in vacuum, they are packaged in a housing 7 without a final seal or cap in an atmosphere with less than 50 ppm moisture. The opened ultracapacitor 10 may be dried, for example, under vacuum over a temperature range of about 100° C. to about 300° C. Once this final drying is complete, electrolyte 6 can be added and housing 7 sealed in a relatively dry atmosphere (eg, an atmosphere having less than about 50 ppm moisture). Of course, other assembly methods may be used, and the foregoing merely provides some exemplary assembly aspects of the ultracapacitor 10 .

III. Methods of the present invention

Specific methods of the present invention for making devices of the present invention or useful for reducing impurities are described below. This method of purification can also be applied to any improved electrolyte system of the present invention.

A. Methods of Reducing Impurities

i. AES contaminants

In certain embodiments, the improved electrolyte system (AES) of the present invention is purified to remove contaminants and provides the desired improved performance characteristics disclosed herein. Accordingly, the present specification provides a method for purifying AES, a method comprising: admixing water in an improved electrolyte system to provide a first mixture; partitioning the first mixture; collecting the improved electrolyte system from the first mixture; adding a solvent to the collected liquid to provide a second mixture; admixing carbon with the second mixture to provide a third mixture; separating the improved electrolyte system from the third mixture to obtain a purified improved electrolyte system. In general, the process calls for addition of deionized water as well as activated carbon under controlled conditions, electrolyte selection. The deionized water and activated carbon are later removed, resulting in a substantially purified electrolyte. The purified electrolyte is particularly suitable for use in ultracapacitors.

The method can be used to ensure a high degree of purity of the improved electrolyte system (AES) of the present invention. It should be noted that although the process is provided for specific parameters (eg, amount, formulation, number of times, etc.), it is merely illustrative of the process for purifying the electrolyte and is not limited thereto.

For example, the method may further comprise one or more of the following steps or features: heating the first mixture; wherein the partitioning includes placing the first mixture undisturbed up to the water and the AES is substantially partitioned; wherein adding the solvent includes adding at least one of diethyl ether, penton, cyclopenton, hexane, cyclohexane, benzene, toluene, 1-4 dioxane and chloroform; Here mixing the carbon includes mixing the carbon powder; wherein mixing the carbon includes stirring the third mixture substantially constantly and frequently; wherein separating the AES comprises at least one of filtering carbon from the third mixture and vaporizing the solvent from the third mixture.

In the first step of the process for purifying the electrolyte, the electrolyte 6 (in some embodiments, an ionic liquid) is mixed with deionized water and then brought to an intermediate temperature for some period of time. In a proof of concept, 50 milliliters (ml) of the ionic liquid was mixed with 850 milliliters (ml) of deionized water. The mixture was raised to a constant temperature of 60° C. for about 12 hours (at about 120 rpm (revolutions per minute)) and stirred constantly.

In a second step, the mixture of ionic liquid and deionized water is allowed to separate. In this example, the mixture was transferred through the funnel and allowed to stand for about 4 hours.

In a third step, an ionic liquid is collected. In this example, the water phase of the mixture was at the bottom and the ionic liquid phase was at the top. The ionic liquid phase was transferred into another beaker.

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 stirred for some time at medium temperature.

Although ethyl acetate was used as the solvent, the solvent may be diethylether, penton, cyclopenton, hexane, cyclohexane, benzene, toluene, 1,4-dioxane, chloroform, or any combination thereof, as well as other solvents exhibiting appropriate performance characteristics. at least one of the substance(s). Some of the desired performance characteristics include those of non-polar solvents and high volatility.

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 (about 0.45 micrometer diameter) was added to the mixture.

In a sixth step, the ionic liquid is mixed again. In this example, the mixture with carbon powder was then stirred constantly (120 rpm) overnight at about 70°C.

In a seventh step, carbon and ethyl acetate are separated from the ionic liquid. In this example, carbon was separated using Buchner filtration with a glass microfiber filter. Multiple filtration methods (3) were performed. The collected ionic liquid was then passed through a 0.2 micrometer syringe filter to remove substantially all of the carbon particles. In this example, the solvent was then subsequently separated from the ionic liquid using rotary evaporation. Specifically, a sample of the ionic liquid is agitated with increasing temperature from 70°C to 80°C, ending at 100°C. Evaporation was carried out for about 15 minutes at each temperature.

The process for purifying the electrolyte has proven to be very effective. For the sample ionic liquid, the water content was determined by titration with a titration instrument (model number: AQC22) provided by Mettler-Toledo Inc. of Columbus, Ohio. Halide content was measured with an ISE instrument (model number (AQC22)) provided by Hanna Instruments of Unsocket, Rhode Island. Standard solutions for ISE instruments were obtained from Hanna, HI 4007-03 (1,000 ppm chloride standard), HI 4010-03 (1,000 ppm fluoride standard), HI 4000-00 (for halide electrodes (ISA)), and HI 4010-00 (TSAB solution for fluoride electrodes only) was included. Before performing measurements, the ISE instrument was calibrated with standard solutions using standards of 0.1, 10, 100 and 1,000 ppm mixed with deionized water. ISA buffer was added to the standard in a 1:50 ratio for the determination of Cl ⁻ ions. The results are shown in Table 3.

A fourth step process was used to measure halide ions. First, Cl ⁻ and F ⁻ ions were measured in deionized water. Next, a 0.01M solution of the ionic liquid was prepared with deionized water. Subsequently, Cl ⁻ and F ⁻ ions were measured in the solution. An estimate of the halide content was then determined by subtracting the amount of ions in the water from the amount of ions in solution.

Purification standards were also tested for electrolyte contaminant composition through analysis of leakage current. 9 shows the leakage current for the crude electrolyte in the ultracapacitor 10 . 10 shows the leakage current for purified electrolyte in a similarly constructed ultracapacitor 10 . As can be seen, there is not only a significant decrease in the initial leakage current, but also a decrease in the leakage current in the next part of the measurement interval. More information is provided on the configuration of each embodiment in Table 4.

Other utilities are also realized, including improvements in resistance stability and capacitance of the ultracapacitor 10 .

The leakage current can be determined in several ways. Qualitatively, leakage current can be considered as the current drawn into the device once the device has reached equilibrium. In fact, it is always or almost always necessary to estimate the actual leakage current as an equilibrium that can generally only be approached asymptotically. Thus, while the ultracapacitor 10 is held at a substantially fixed voltage and exposed to a substantially fixed ambient temperature for a relatively long period of time, the leakage current in a given measurement can be approximated by measuring the current drawn into the ultracapacitor 10 . can In some cases, the relatively long period can be determined by approximating the current time function as an exponential function and then allowing it to pass through some (eg, about 3-5) characteristic time constants. Often, such durations range from about 50 hours to about 100 hours for many ultracapacitor technologies. Alternatively, if such a long period is impractical for any reason, the leakage current can be inferred, again, perhaps, simply by approximating the current time function as an exponential or any approximate function that appears to be appropriate. In particular, the leakage current will generally depend on the ambient temperature. Thus, in order to characterize the performance of a device at a certain temperature or over a range of temperatures, it is generally important to expose the device to the ambient temperature of interest when measuring leakage current.

Note that one approach to reducing the volumetric leakage current at a certain temperature is to reduce the operating voltage at this temperature. Another approach to reducing volume leakage current at certain temperatures is to increase the empty volume of the ultracapacitor. Another approach to reducing the leakage current is to reduce the load of the energy storage medium 1 at the electrode 3 .

Although aspects of embodiments for the purification of electrolytes and ionic liquids have been described, it should be appreciated that other embodiments may be practiced. In addition, various techniques may be performed. For example, the steps may be adjusted, such as the order of the steps.

ii. Moisture/moisture content and removal

The housing 7 of the sealed ultracapacitor 10 can be opened and the storage cell 12 can be sampled for impurities. The water content was measured using the Karl Fischer method for the electrodes, separators and electrolytes of the cell 12 . Three measurements were taken and the average calculated.

In general, a method for characterizing a contaminant in an ultracapacitor comprises breaching the housing 7 to access its content, sampling the content, and analyzing the sample. Techniques disclosed elsewhere herein may be used to assist in characterization.

To ensure accurate measurement of impurities in ultracapacitors and their components (including electrodes, electrolytes and separators), assembly and disassembly can be performed in an appropriate environment, such as an inert environment within a glove box.

By reducing the water content in the ultracapacitor 10 (eg, to less than 1,000 ppm) impurities and less than 500 ppm by weight and volume of the electrolyte, the ultracapacitor 10 can be controlled over a temperature range, at its temperature. It can operate efficiently with a leakage current (I/L) of less than 10 Amp per liter within range and voltage range.

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

In some embodiments, the maximum rated voltage of ultracapacitor 10 is about 4 V at room temperature. An approach to ensuring the performance of the ultracapacitor 10 at elevated temperatures (eg, 210° C. or higher) is to lower (ie, reduce) the rated voltage of the ultracapacitor 10 . For example, the rated voltage can be adjusted down to about 0.5 V, realizing extended operating durations at higher temperatures.

B. Method of Manufacturing Ultracapacitors

In another embodiment, the present invention provides a method of manufacturing an ultracapacitor comprising the steps of: placing an energy storage cell comprising an energy storage medium in a housing; and filling the housing with an Advanced Electrolyte System (AES) to produce an ultracapacitor operating within a temperature range of about -40°C to about 210°C.

In certain embodiments, the AES comprises a novel electrolyte material (NEE), for example, the NEE is adapted for use in high temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about 80°C to about 210°C, for example, a temperature range of about 80°C to about 150°C.

In certain embodiments, the AES comprises, for example, a highly purified electrolyte, the highly purified electrolyte being adapted for high temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about 80°C to about 210°C, for example, a temperature range of about 80°C to about 150°C.

In certain embodiments, the AES includes an improved electrolyte combination, eg, the improved electrolyte combination is adapted for use in both high and low temperature ultracapacitors. In certain embodiments, the ultracapacitor is configured to operate at a temperature within a temperature range of about -40°C to about 150°C, for example, a temperature range of about -30°C to about 125°C.

In one embodiment, the manufactured ultracapacitor is the ultracapacitor described in Section II above. As such, and as described above, the advantages over existing electrolytes of known energy storage devices include the following improvements: reduced total resistance, increased long-term stability of resistance, increased total capacitance, increased long-term stability of capacitance, increased energy selected from one or more of density, elevated voltage stability, reduced vapor pressure, wider temperature range performance for individual capacitors, elevated temperature endurance for individual capacitors, increased ease of manufacturability, and improved cost effectiveness.

In certain embodiments, disposing further comprises pre-treating the components of the ultracapacitor including at least one of an electrode, a separator, a lead, an assembled energy storage cell, and a housing to reduce moisture therein. do. In certain embodiments, the pre-treating includes heating the selected components under vacuum to a temperature range of substantially from about 100° C. to about 150° C. The pre-treating may include heating the selected components under vacuum over a temperature range of substantially from about 150° C. to about 300° C.

In certain embodiments, the disposing step is performed in a substantially inert environment.

In certain embodiments, building comprises selecting an interior facing material for a housing that exhibits low chemical reactivity with the electrolyte, including the interior facing material in a substantial portion of the interior of the housing. It may include further steps. This interior facing material may be selected from at least one of aluminium, polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and a ceramic material. have.

In certain embodiments, building comprises forming a housing from the multilayer material, eg, forming the housing from the multilayer material comprises disposing a weldable material on an exterior of the housing. do.

In certain embodiments, building includes manufacturing at least one of a cap and a body for the housing. The manufacturing step may include disposing within the housing a seal comprising an insulator and an electrode insulated from the housing. Moreover, disposing the seal includes disposing a glass-to-metal seal, eg, welding the glass-to-metal seal to an outer surface of the housing. In certain embodiments, disposing the seal includes disposing a hemispherical seal.

In certain embodiments, the step of building includes providing a filling port in the housing to provide for the filling step.

In certain embodiments, the manufacturing method comprises manufacturing an energy storage cell, eg, coupling an energy storage medium with a current collector to obtain an electrode, eg, coupling at least one lead to the electrode. It may include further steps. In certain embodiments, coupling the at least one lead to the electrode includes placing the at least one fiducial mark on the electrode. In certain embodiments, coupling the at least one lead to the electrode includes positioning each lead at a respective fiducial mark. In certain embodiments coupling the at least one lead includes clearing the energy storage medium from the current collector. In certain embodiments, coupling the at least one lead includes ultrasonically welding the lead to a current collector.

The electrode may also be obtained by combining a plurality of electrode elements produced from the step of combining the energy storage medium with the current collector. The plurality of electrode elements may be joined by ultrasonically welding one coupling element to the current collector of one electrode element and to the current collector of another electrode element.

In certain embodiments, manufacturing the energy storage cell includes disposing a separator between at least two electrodes. The method may further include aligning each electrode with the separator.

In certain embodiments, manufacturing the energy storage cell comprises packing at least two electrodes and a separator disposed therebetween, eg, packing the rolled storage cell. rolling to become a storage cell.

In certain embodiments, manufacturing the energy storage cell includes placing a wrapper over the storage cell.

In certain embodiments, disposing the energy storage cell includes grouping a plurality of leads together to provide a terminal, eg, grouping the plurality of leads together to form a terminal. aligning the leads into an ordered set of reads. In certain embodiments, the method includes placing a wrapper on an aligned set of leads, applying a fold to the aligned set of leads, or coupling the aligned set of leads to a contact of a housing It further includes the step of making Also, coupling includes welding the aligned set of leads to the contact, or welding the aligned set of leads to one of the jumper and the bridge to couple the contact to the contact of the housing.

In certain embodiments, the manufacturing method may further include electrically coupling at least one of the jumper and the bridge to the contact portion of the housing. In certain embodiments, this may further include disposing an insulating material substantially over the contacts within the housing.

In certain embodiments, the method of manufacturing may further include hermetically sealing the energy storage cell within the housing, eg, hermetically sealing the components of the housing together by pulse welding, laser welding. It includes at least one of the step of welding, resistance welding, and TIG welding.

In certain embodiments, the manufacturing method may further comprise mating at least one cap with the body to provide a housing, eg, the cap may be one of a concave cap, a convex cap and a flat cap. contains at least one. In certain embodiments, the method may further include removing at least a portion of the multilayer material of the housing to provide a mating step.

In certain embodiments, the manufacturing method may further comprise purifying the AES.

In certain embodiments, the manufacturing method further comprises disposing a fill port in the housing, eg, the filling comprises disposing the AES on the fill port of the housing. In certain embodiments, the method further comprises sealing the fill port upon completion of the fill, eg, fitting a commercial material to the fill port. This material can then be welded to the housing in another step.

In certain embodiments, the filling step includes drawing a vacuum in the filling port of the housing, eg, the vacuum is about 150 mTorr or less, eg the vacuum is about 40 mTorr or less.

In certain embodiments, the filling step is performed in a substantially inert environment.

i. manufacturing technology

It should also be appreciated that certain robust assembly techniques may be required to provide highly efficient energy storage. Accordingly, some techniques for assembly are now discussed.

Once the ultracapacitor 10 is fabricated, it can be used in high temperature applications with little or no leakage current and little increase in resistance. The ultracapacitor 10 disclosed herein has a leakage current of about -40° C. It can operate effectively at temperatures of from to about 210°C. In certain embodiments, the capacitor is operable over a temperature of -40°C to 210°C.

As an overview, a method for assembling a cylindrical ultracapacitor 10 is provided. Starting with electrodes 3 , each electrode 3 is manufactured if an energy storage medium 1 has been associated with a current collector 2 . A plurality of leads are then coupled to each electrode 3 at appropriate positions. A plurality of electrodes (3) is then oriented and assembled with an appropriate number of separators (5) therebetween to constitute a storage cell (12). The storage cell 12 can then be rolled into the cylinder and secured with a wrapper. Typically, individual leads are then bundled to form respective terminals 8 .

Prior to incorporation of the electrolyte 6 (ie, the improved electrolyte system of the present invention) into the ultracapacitor 10 (eg, before or after assembly of the storage cell 12 ), the Each component may be dried to remove moisture. This can be done with unassembled components (ie the empty housing 7 as well as each of the electrodes 3 and each of the separators 5) and subsequently assembled components (eg, storage cell 12).

For example, drying may be performed at an elevated temperature in a vacuum environment. Once drying has been performed, the storage cell 12 can be packaged in the housing 7 without a final seal or cap. In some embodiments, packaging is performed in an atmosphere having less than 50 ppm moisture. The lidless ultracapacitor 10 can then be dried again. For example, the ultracapacitor 10 may be dried under vacuum for a temperature range of about 100°C to 300°C. Once this final drying is complete, the housing 7 can be sealed in an atmosphere with, for example, less than 50 ppm moisture.

In some embodiments, once the drying process (also referred to as "baking" process) is complete, the environment surrounding the components may be filled with an inert gas. Exemplary gases include argon, hydrogen, helium, and other gases exhibiting similar properties (as well as combinations thereof).

In general, a filling port (a hole in the surface of the housing 7 ) may be included in the housing 7 or added later. Once the ultracapacitor 10 has been filled with the electrolyte 6 , ie the improved electrolyte system of the present invention, the fill port can then be closed. Closing the fill port may be completed, for example, by welding a material (eg, a metal compatible with the housing 7 ) into or over the fill port. In some embodiments, the fill port can be temporarily closed prior to filling, so that the ultracapacitor 10 can be moved to a different environment for subsequent re-opening, filling and closing. However, as discussed herein, ultracapacitor 10 is contemplated to be dried and filled in the same environment.

A number of methods can be used to fill the housing 7 with a desired amount of electrolyte 6 . In general, control of the filling process can provide, inter alia, increase in capacitance, decrease in equivalent series resistance (ESR), and limit waste of electrolyte 6 . A vacuum filling method is provided as a non-limiting example of a technique for filling the housing 7 and immersing the storage cell 12 with the electrolyte 6 .

First, however, it is noted that steps may be taken to ensure that any material that has the potential to contaminate the components of the ultracapacitor 10 can be cleaned, compatible, and dried. Typically, it can be considered that “good hygiene” is done to ensure that the assembly processes and components do not introduce contaminants into the ultracapacitor 10 .

In the “vacuum method” the container is placed on a housing 7 around the filling port. The electrolyte 6, ie, the improved electrolyte system of the present invention, is then placed in a container in an environment that is substantially free of oxygen and moisture (ie, moisture). A vacuum environment is then created, thereby evacuating any air out of the housing, thereby drawing the electrolyte 6 into the housing 7 at the same time. The ambient environment may then be backfilled with an inert gas (eg, argon, hydrogen, etc., or some combination of inert gases) if desired. The ultracapacitor 10 may be inspected to see if the desired amount of electrolyte 6 has been drawn. The process may be repeated as needed until the desired amount of electrolyte 6 is in the ultracapacitor 10 .

In certain embodiments, after filling with the electrolyte 6 , ie, the improved electrolyte system of the present invention, the material may be fitted into a filling port to seal the ultracapacitor 10 . The material may be, for example, a metal compatible with the housing 7 and the electrolyte 6 . In one example, the material force fit to the fill port, substantially performing a "cold weld" of the plug to the fill port. In certain embodiments, the steel fitting may be supplemented with other welding techniques as discussed further herein.

In general, assembly of the housing often involves placing the storage cell 12 within the body 20 and filling the body 20 with electrolyte 6 . Another drying process may be performed. Exemplary drying includes heating a body 20 having a storage cell 12 and electrolyte 6 therein, often under reduced pressure (eg, vacuum). Once adequate (optional) drying has been carried out, the final assembly steps can be carried out. In the final steps, the internal electrical connections are made, the cap 24 is installed, and the cap 24 is hermetically sealed to the body 20 by, for example, welding the cap 24 to the body 20 . .

In some embodiments, at least one of housing 7 and cap 24 comprises a material comprising multiple layers. For example, the first material layer may include aluminum, and the second material layer may be stainless steel. In this example, stainless steel is clad on aluminum, providing a material exhibiting the desired combination of metallurgical properties. That is, in the embodiments provided herein, the aluminum is exposed to the inside of the energy storage cell (ie, the housing), while the stainless steel is exposed to the outside. In this way, while having the advantageous electrical properties of aluminum, it relies on the structural properties (and metallurgical properties, ie weldability) of stainless steel for construction. The multilayer material may include additional layers deemed suitable. Preferably, this provides for welding of stainless steel to stainless steel, ie, a relatively simple welding procedure.

Materials used in the construction of body 20 include aluminum, any type of aluminum or aluminum alloy deemed suitable by the designer or manufacturer, all of which are broadly referred to herein simply as “aluminum”. . Various alloys, laminates, etc. may be disposed (eg, cladded) on aluminum (aluminum exposed on the interior of body 20 ). Additional materials (such as some polymer-based materials, electrically insulating materials or structural materials) may be used to complement the body and/or housing 7 . The material to be disposed on the aluminum may likewise be selected as deemed appropriate by the designer or manufacturer.

The use of aluminum is not necessary or required. That is, a choice of materials may be provided for use of any material deemed appropriate by a designer, manufacturer, or user, or the like. Considerations may relate to other factors such as, for example, reduction of electrochemical interactions with electrolyte 6 , structural properties, cost, and the like.

Embodiments of the ultracapacitor 10 exhibiting a relatively small volume may be fabricated in a prismatic form factor, such that the electrodes 3 of the ultracapacitor 10 face each other, with at least one electrode 3 ) have internal contacts for glass-to-metal seals, others have internal contacts for housing or glass-to-metal seals.

The volume of a particular ultracapacitor 10 can be expanded by assembling (eg, welding several jellyrolls together) several storage cells within one housing 7 such that they are electrically parallel or in series.

In various embodiments, it is useful to use a plurality of ultracapacitors 10 to provide a power supply. To provide reliable operation, individual ultracapacitors 10 are tested prior to use. To perform various types of tests, each of the ultracapacitors 10 may be tested as a single cell to which a plurality of ultracapacitors 10 are attached, either in series or in parallel. The use of different metals joined by various techniques (eg, by welding) can not only reduce the ESR of the connection, but also increase the strength of the connection. Now, some aspects of the connection between ultracapacitors 10 are introduced.

In some embodiments, ultracapacitor 10 includes two contacts. The two contacts are the glass-to-metal sealing pin (ie the feed-through 19 ) and the entire remainder of the housing 7 . When connecting a plurality of ultracapacitors 10 in series, it is often desirable to couple the interconnection between the bottom of the housing 7 (in the case of the cylindrical housing 7 ), so that the distance to the inner lead is is minimized and thus has the least resistance. In this embodiment, the opposite end of the interconnect is usually coupled to a pin of a glass-to-metal seal.

Regarding interconnections, a common type of welding involves the use of a parallel tip electric resistance welder. Welding can be accomplished by aligning the ends of the interconnect on the pin and welding the interconnect directly to the pin. The use of multiple welds will increase the strength and connection between the interconnect and the pin. In general, when welding to a pin, shaping the ends of the interconnect to better match the pin serves to ensure that there is substantially no excess material overlapping the pin causing a short circuit.

A opposed tip electric resistance welder may be used to weld the interconnect to the pins, while an ultrasonic welder may be used to weld the interconnect to the bottom of the housing 7 . Soldering techniques can be used if the metals involved are commercially available.

Regarding the material used in the interconnect, a common type of material used for the interconnect is nickel. Nickel can be used because it welds well with stainless steel and has a strong interface. For example, other metals and alloys may be used in place of nickel to reduce resistance in the interconnect.

In general, the material selected for the interconnect is selected to be compatible with the material within the pin as well as the material within the housing 7 . Exemplary materials include copper, nickel, tantalum, aluminum and nickel copper cladding. Additional metals that may be used include silver, gold, brass, platinum and tin.

In some embodiments, for example, where the pins (ie, feed-through 19 ) are made of tantalum, the interconnect may utilize an intermediate metal, eg, by using short bridge connections. An exemplary bridge connection includes a strip of tantalum, modified using a counter tip resistance welder to weld a strip of aluminum/copper/nickel to the bridge. A parallel resistance welder is then used to weld the tantalum strip to the tantalum pin.

A bridge can also be used on the contact, which is the housing 7 . For example, the nickel piece may be a resistor welded to the bottom of the housing 7 . The copper strip may then be ultrasonically welded to the nickel bridge. This technique helps to reduce the resistance of the cell interconnects. Using different metals for each connection can reduce the ESR of the interconnect between cells in series.

Accordingly, in describing aspects of a powerful ultracapacitor 10 useful in high temperature environments (ie, up to about 210° C.), some additional aspects are now provided and/or defined.

A variety of materials may be used in the construction of the ultracapacitor 10 . The integrity of the ultracapacitor 10 is essential when oxygen and moisture must be excluded and the electrolyte 6 must be prevented from escaping. To achieve this, seam welds and any other sealing points must meet standards for tightness over the intended temperature range for operation. In addition, the material selected should be compatible with other materials such as ionic liquids and solvents that may be used in the formulation of the electrolyte 6 .

In some embodiments, the feed-through 19 is KOVAR ^™ (trademark of Carpenter Technology Corporation of Reading, PA, KOVAR is a vacuum melted iron-nickel-cobalt, i.e., low expansion alloy, the chemical composition of which is Controlled within a narrow range to ensure accurate uniform thermal expansion properties), alloy 52 (nickel iron alloy suitable for glass and ceramic sealing to metal), tantalum, molybdenum, niobium, tungsten, stainless steel ( 446) (ferritic, non-heat treatable stainless steel that provides excellent resistance to high temperature corrosion and oxidation) and titanium.

The body of the glass-to-metal seal utilizing the above may be made of 300 series stainless steel, such as 304, 304L, 316, and 316L alloys. The body is also made of Inconel (a family of austenitic nickel-chromium-based superalloys, which are oxidation and corrosion resistant materials well suited for service in extreme environments receiving pressure and heat) and Hastelloy (a different ratio than nickel). of metals such as at least one of other nickel alloys such as molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon, and metal alloys with high corrosion resistance (including tungsten).

In a glass-to-metal seal, the insulating material between the enclosing body and the feed-through 19 is generally glass, the composition of which is proprietary to each manufacturer of the seal and depends on whether the seal is under compression or is matched. Other insulating materials may be used for glass-to-metal sealing. For example, other polymers may be used for sealing. As such, the term "glass to metal" seal merely describes the type of seal and is not intended to imply that the seal must include glass.

The housing 7 for the ultracapacitor 10 may be made of, for example, type 304, 304L, 316 and 316L stainless steel. They may also be composed of some of the aluminum alloys such as, but not limited to, 1100, 3003, 5052, 4043, 6061. A variety of multilayer materials may be used, including, for example, an aluminum clad to stainless steel. Other non-limiting compatible metals that may be used include platinum, gold, rhodium, ruthenium and silver.

Specific examples of glass-to-metal seals used in ultracapacitors 10 include two different types of glass-to-metal seals. The first is from SCHOTT, based in Elmsford, New York, USA. This embodiment uses stainless steel pins, glass insulators, and a stainless steel body. The second glass-to-metal seal is from HERMETIC SEAL TECHNOLOGY of Cincinnati, Ohio. This second embodiment uses tantalum pins, glass insulators and a stainless steel body. Several embodiments of various sizes may be provided.

A further example of a glass-to-metal seal is an embodiment using an aluminum seal and an aluminum body. Another example of a glass-to-metal seal involves an aluminum seal using an epoxy or other insulating material (eg, ceramic or silicon).

A plurality of aspects for glass-to-metal sealing may be configured as desired. For example, the dimensions of the housing and the pin and the material of the pin and the housing can be modified as appropriate. The fins may also be tubes or solid fins as well as having multiple fins in one cover. The most common types of materials used for pins are stainless steel alloys, copper cored stainless steel, molybdenum, platinum-iridium, other nickel-iron alloys, tantalum and other metals, although some non-conventional materials are available. can be used (eg, aluminum). The housing is generally constructed of stainless steel, titanium and/or other materials.

Other fastening techniques may be used in assembling the ultracapacitor 10 . For example, with respect to welding, other welding techniques may be used. An exemplary listing of the types of welds and other uses in which each type of weld may be used follows.

welding aluminum tabs to the current collector; welding the tabs to the bottom clad cover; welding jumper tabs to the clad bridge connected to the glass-to-metal sealing pin; and to weld the jellyroll tabs together, ultrasonic welding may be used, among other things. welding the leads to the bottom or pin of the can; welding the leads to the current collector; Weld the jumper to the clad bridge; welding the clad bridge to the terminal (8); To weld the leads to the bottom cover, pulse or resistance welding may be used, among other things. welding the stainless cover to the stainless steel can; welding a stainless steel bridge to a stainless steel glass-to-metal sealing pin; To weld the plug to the fill port, laser welding may be used, among other things. sealing the aluminum cover to the aluminum can; To weld an aluminum seal in place, TIG welding may be used, among other things. Cold welding (compressing metals together with great force) can be used, among other things, to seal the fill port by force fitting an aluminum ball/tack to the fill port.

ii. Certain advantageous embodiments of manufacture

Certain advantageous embodiments are provided below, which are not intended to be limiting.

In a particular embodiment, and with reference to FIG. 29 , the components of an exemplary electrode 3 are shown. In this example, electrode 3 will be used as negative electrode 3 (however, this designation is arbitrary and for reference only).

As mentioned in the description, at least in this embodiment, the separator 5 generally has a longer length and a wider width than the energy storage medium 1 (and the current collector 2 ). By using a large separator 5, protection against short circuiting of the positive electrode 3 and the negative electrode 3 is provided. The use of additional material in the separator 5 also provides better electrical protection for the leads and terminals 8 .

Reference is now made to FIG. 30 , which provides a side view of an embodiment of a storage cell 12 . In this example, the stacked stack of energy storage medium 1 includes a first separator 5 and a second separator 5 , so that when the storage cell 12 is assembled to the rolled storage cell 23 , the electrode (3) is electrically isolated. The terms “positive” and “negative” relating to the assembly of the electrode 3 and the ultracapacitor 10 are simply arbitrary, and refer to functionality when constructed in the ultracapacitor 10 and an electric charge is stored therein. Note that it is This convention, universally adopted in the art, is not intended to reflect that charge is stored prior to assembly, or to imply any other aspect other than providing for the physical identification of different electrodes.

Before winding the storage cell 12 , the negative electrode 3 and the positive electrode 3 are aligned with respect to each other. The alignment of the electrodes 3 provides better performance of the ultracapacitor 10 as the path length for ion transport is generally minimized when the highest level of alignment is present. Also, by providing a high level of alignment, the excess separator 5 is not included, and consequently the efficiency of the ultracapacitor 10 is not deteriorated.

Referring now also to FIG. 31 , there is shown an embodiment of a storage cell 12 wound such that the electrode 3 becomes a rolled 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 interior of the housing 7 .

“Polarity matching” may be used to match the polarity of the body 20 with the polarity of the outermost electrode of the rolled storage cell 23 . For example, in some embodiments, the negative electrode 3 is on the outermost side of the tightly packed package providing the rolled storage cell 23 . In this embodiment, another level of protection against short circuits is provided. That is, when the negative electrode 3 is coupled to the body 20 , the negative electrode 3 is disposed as the outermost electrode of the rolled storage cell 23 . Thus, for example, in case the separator 5 fails due to mechanical wear induced by vibration of the ultracapacitor 10 during use, the ultracapacitor 10 is the outermost electrode and body of the rolled storage cell 23 . It will not fail due to a short circuit between (20).

For each embodiment of the rolled storage cell 23 , the fiducial mark 72 may be at least on the separator 5 . The fiducial marks 72 will be used to provide positioning of the leads at each of the electrodes 3 . In some embodiments, the determination of the position of the lead is provided by calculation. For example, in consideration of the overall thickness of the separator 5 and the electrode 3 combined with the inner diameter of the jelly roll, the arrangement position of each lead may be estimated. However, in practice it has been shown that the use of fiducial marks 72 is more efficient and effective. The fiducial mark 72 may include, for example, a slit at the edge of the separator(s) 5 .

In general, a fiducial mark 72 is used for each new specification of the storage cell 12 . That is, the use of the previous fiducial mark may be at least somewhat inaccurate, as the new specification of the storage cell 12 may require a different thickness of at least one layer therein (relative to the previous embodiment). .

In general, fiducial mark 72 is indicated by a single radial line traversing the roll from its center to its perimeter. Thus, when leads are installed along fiducial marks 72, each lead will be aligned with the other leads (as shown in FIG. 10). However, when the storage cell 12 is unrolled (for embodiments in which the storage cell 12 is or is rolled), the fiducial mark 72 may be considered to be a plurality of markings (Fig. 32). For convenience, irrespective of the appearance or embodiment of the presentation of the storage cell 12, it is considered that the identification of the location for the incorporation of a lead entails the identification of a "fiducial mark 72" or a "set of fiducial marks 72". do.

Referring now to FIG. 32 , once fiducial marks 72 have been established (eg, by marking on rolled storage cells 12 ), an installation site is provided for installation of each lead (ie fiducial marks 72 ). described by). Once each installation site is identified, for any given build specification of storage cell 12 , the relative location of each installation site can be repeated for additional instances of that particular build of storage cell 12 . .

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 the width W, but the leads may only be coupled over a portion of the width W. Coupling can be achieved, for example, by ultrasonic welding of the leads to the current collector 2 . To achieve the coupling, at least a portion of the energy storage medium 1 can be (suitably) removed so that each lead can be properly joined with the current collector 2 . Other manufacture and acceptance may be practiced as deemed appropriate to provide a coupling.

In certain embodiments, opposing fiducial marks 73 may be included. That is, in the same way that fiducial marks 72 are provided, a set of opposing fiducial marks 73 can be made to illustrate the installation of leads for opposing polarities. That is, the fiducial mark 72 can be used to install a lead to the first electrode 3 such as the negative electrode 3 , while the opposite fiducial mark 73 is used to install the lead to the positive electrode 3 . can be used for In the embodiment in which the rolled storage cell 23 is cylindrical, opposing fiducial marks 73 are disposed on opposite sides of the energy storage medium 1 and are longitudinally offset from the fiducial marks 72 (as shown). .

Note that in FIG. 32 , both the fiducial mark 72 and the opposing fiducial mark 73 are shown disposed on a single electrode 3 . That is, FIG. 29 simply shows an embodiment for illustrating the spatial (ie, linear) relationship between the fiducial mark 72 and the opposing fiducial mark 73 . This is not intended to imply that the positive electrode 3 and the negative electrode 3 share the energy storage medium 1 . However, when the fiducial mark 72 and the opposing fiducial mark 73 are arranged by rolling the storage cell 12 and marking on the separator 5, the fiducial mark 72 and the opposing fiducial mark 73 must be It should be noted that it may be provided on a single separator 5 . However, in practice, only one set of fiducial marks 72 and opposing fiducial marks 73 are used to install leads for any given electrode 3 . That is, it should be appreciated that the embodiment shown in FIG. 32 will be supplemented with another layer of energy storage medium 1 for another electrode 3 which will be of opposite polarity.

33 , the assembly technique described above results in the storage cell 12 comprising at least one set of aligned leads. A first set of aligned leads 91 are particularly useful when coupling a rolled storage cell 23 to one of a negative contact 55 and a positive contact 56 , while a set of oppositely aligned leads 92 provides coupling of the energy storage medium 1 to opposing contacts 55 , 56 .

The rolled storage cell 23 may be surrounded by a wrapper 93 . The wrapper 93 may be realized in various embodiments. For example, the wrapper 93 may be provided as a KAPTON ^™ tape (a polyimide film developed by DuPont, Wilmington, Del.), or a PTFE tape. In this example, the KAPTON ^™ tape surrounds the rolled storage cell 23 and is attached. The wrapper 93 may be provided without adhesive, such as a tightly fitting wrapper 93 that slides onto the rolled storage cell 23 . The wrapper 93 may be specified as a bag, which generally completely encloses the rolled storage cell 23 (eg, such as the envelope 73 discussed above). In some of these embodiments, the wrapper 93 may comprise a material that functions as a shrink-wrap, thereby providing an efficient physical (and, in some embodiments, chemical) enclosure of the rolled storage cell 23 . Generally, the wrapper 93 is made of a material that does not interfere with the electrochemical function of the ultracapacitor 10 . The wrapper 93 may also provide partial coverage as needed, for example to aid insertion of the rolled storage cell 23 .

In some embodiments, the negative electrode lead and the positive electrode lead are located on opposite sides of the rolled storage cell 23 (in the case of the jellyroll type rolled storage cell 23 , negative polarity leads and positive electrode lead) The leads of polarity of may be opposite). In general, placing the negative polarity leads and the positive polarity leads on opposite sides of the rolled storage cell 23 facilitates construction of the rolled storage cell 23 as well as provides improved electrical isolation. is done to

In some embodiments, once aligned leads 91 , 92 are assembled, each of the plurality of aligned leads 91 , 92 is tied together (in place) such that a shrink-wrap (not shown) forms a plurality of It may be disposed around the aligned leads 91 , 92 . Generally, the shrink-wrap is constructed of PTFE, although any suitable material may be used.

In some embodiments, once a shrink-wrap material is placed against the aligned lead 91 , the aligned lead 91 folds into a shape contemplated when the ultracapacitor 10 is assembled. . That is, referring to FIG. 34 , it can be seen that it is assumed that the aligned leads have a “Z” shape. After applying a “Z-fold” to the aligned leads 91 , 92 , the shrink-wrap is heated or otherwise Otherwise, it can be activated. Accordingly, in some embodiments, aligned leads 91 , 92 may be reinforced and protected by a wrapper. The use of a Z-fold is particularly useful when coupling an energy storage medium to a feed-through 19 disposed within the cap 24 .

Also, other embodiments for coupling each set of aligned leads 91 , 92 (ie, each terminal 8 ) to respective contacts 55 , 56 may be practiced. For example, in one embodiment, an intermediate lead is coupled to one of the feed-through 19 and housing 7 , such that the Coupling is easy.

Moreover, the material used may be selected according to characteristics such as reactivity, dielectric value, melting point, adhesion to other materials, weldability, coefficient of friction, cost and other such factors. Combinations of materials (eg, layered, mixed, or otherwise combined) can be used to provide the desired properties.

iii. Specific Ultracapacitor Examples

Physical aspects of an exemplary ultracapacitor 10 of the present invention are shown below. In the tables below, the term “tab” generally refers to “lead” as described above; The terms "bridge" and "jumper" also refer to aspects of a lead (eg, a bridge may be coupled to a feed-through or a "pin", while a jumper is used to connect the bridge to taps or leads). Note that useful). The use of a variety of connections facilitates the assembly process and may utilize specific assembly techniques. For example, the bridge may be laser welded or resistance welded to the pin and ultrasonically welded to the jumper.

35-38 are graphs illustrating the performance of an exemplary ultracapacitor 10 . 35 and 36 depict the performance of the ultracapacitor 10 at 1.75 Volts and 125°C. 37 and 38 depict the performance of the ultracapacitor 10 at 1.5 Volts and 150°C.

In general, ultracapacitor 10 may be used under different environmental conditions and needs. For example, the terminal voltage may range from about 100 mV to 10 V. Ambient temperatures may range from about -40°C to +210°C. Typical high ambient temperatures range from +60°C to +210°C.

39-43 are additional graphs illustrating the performance of an exemplary ultracapacitor 10 . In this example, the ultracapacitor 10 was a closed cell (ie, a housing). The ultracapacitor was cycled 10 times with a charge and discharge of 100 mA, charged to 0.5 Volts, measured resistance, discharged to 10 mV, rested for 10 seconds and cycled again.

Tables 11 and 12 provide performance comparison data for an embodiment of the ultracapacitor 10 . As shown, performance data was collected for different operating conditions.

Accordingly, the data provided in Tables 9 and 10 demonstrate that the teachings herein achieve the performance of ultracapacitors under extreme conditions. Ultracapacitors thus prepared exhibit, for example, a leakage current of less than about 1 mA per milliliter of cell volume, and an ESR increase of less than about 100% at 500 hours (voltages less than about 2V and less than about 150°C). while maintaining the temperature). As trade-offs can be made between the different needs of the ultracapacitor (e.g. voltage and temperature), performance ratings for the ultracapacitor can be managed (e.g. ESR, rate of increase for capacitance) , can be adapted to accommodate specific needs. With reference to the foregoing, "performance rating" is given as a general conventional definition of the value of a parameter that describes the conditions of operation.

35-43 depict the performance of an exemplary ultracapacitor having an AES comprising 1-butyl-1-methylpyrrolidinium and tetracyanoborate for temperatures in the range of 125°C to 210°C.

44A and 44B depict performance data of an exemplary ultracapacitor having an AES comprising 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide.

45A and 45B depict performance data of an exemplary ultracapacitor having an AES comprising trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide.

46A and 46B depict performance data of an exemplary ultracapacitor having an AES comprising butyltrimethylammonium bis(trifluoromethylsulfonyl)imide.

47A and 47B depict performance data of an exemplary ultracapacitor having an AES comprising 1-butyl-1-methylpyrrolidinium and tetracyanoborate at 125°C.

48A and 48B and 49 show AES comprising a mixture of propylene carbonate and 1-butyl-1-methylpyrrolidinium and tetracyanoborate, about 37.5% propylene carbonate by volume. Depicts performance data of an exemplary ultracapacitor; Capacitors operating at 125°C ( FIGS. 48A and 48B ) and capacitors operating at -40°C ( FIG. 49 ). Other exemplary ultracapacitors tested included AES with 1-butyl-3-methylimidazolium tetrafluoroborate.

Another exemplary ultracapacitor tested included an AES comprising 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

Another exemplary ultracapacitor tested included an AES comprising 1-ethyl-3-methylimidazolium tetrafluoroborate.

Another exemplary ultracapacitor tested included an AES comprising 1-ethyl-3-methylimidazolium tetracyanoborate.

Another exemplary ultracapacitor tested included an AES comprising 1-hexyl-3-methylimidazolium tetracyanoborate.

Another exemplary ultracapacitor tested included an AES comprising 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

Another exemplary ultracapacitor tested included an AES comprising 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate.

Another exemplary ultracapacitor tested included an AES comprising 1-butyl-1-methylpyrrolidinium tetracyanoborate.

Another exemplary ultracapacitor tested included an AES comprising 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

Another exemplary ultracapacitor tested included an AES comprising 1-ethyl-3-methylimidazolium tetracyanoborate.

Another exemplary ultracapacitor tested included AES with 1-ethyl-3-methylimidazolium and 1-butyl-1-methylpyrrolidinium and tetracyanoborate.

Another exemplary ultracapacitor tested included AES with 1-butyl-1-methylpyrrolidinium and tetracyanoborate and ethyl isopropyl sulfone.

Note that the measurement of capacitance as well as ESR, as presented in Table 9 and elsewhere herein, follows generally known methods. First, consider a technique for measuring capacitance.

Capacitance can be measured in multiple ways. One method involves monitoring the voltage presented at the capacitor terminals while a known current is drawn from the ultracapacitor (during “discharge”) or supplied to the ultracapacitor (during “charging”). More specifically, we can take advantage of the fact that the ideal capacitor is governed by the following equation:

I = C*dV/dt

Here, 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, among other things, has zero internal resistance and whose capacitance is voltage independent. When the charging current I is constant, the voltage V is linear with time, so dV/dt can be calculated as the slope of the sea line segment, or as DeltaV/DeltaT. However, these methods are generally approximate, and the voltage difference provided by the effective series resistance (ESR drop) of the capacitor should be taken into account when calculating or measuring the capacitance. Effective series resistance (ESR) may generally be a lumped element approximation of dissipation or other effects in a capacitor. Capacitor operation is often derived from a circuit model comprising an ideal capacitor in series with a resistor with a resistance value equal to ESR. In general, this yields a good approximation of actual capacitor operation.

In one method of measuring capacitance, the method can largely neglect the effect of ESR drop when the internal resistance is substantially independent of voltage, and the charge or discharge current is substantially fixed. In that case, the ESR drop can be approximated as a constant and is naturally subtracted from the calculation of the change in voltage during constant current charging or discharging. The change in voltage then substantially reflects the change in charge stored in the capacitor. Thus, the change in voltage can be taken as an indicator of capacitance, through calculations.

For example, during a constant current discharge, the constant current I is known. During the measurement time interval DeltaT, measure the voltage change DeltaV during discharge and divide the current value I by the ratio DeltaV/DeltaT to approximate the capacitance. When I is measured in Amps, DeltaV in Volts, and DeltaT in Seconds, the capacitance result will be in farads.

Referring to the estimation of ESR, the effective series resistance (ESR) of an ultracapacitor can also 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 the ultracapacitor (during “discharge”) or supplied to the ultracapacitor (during “charging”). More specifically, the method may take advantage of the fact that ESR is governed by the following equation:

V = I*R

Here, I effectively represents the current passing through the ESR, R represents the resistance of the ESR, and V represents the voltage difference (ESR drop) provided by the ESR. ESR may generally be an approximation of the concentration component of dissipation or other effects within an ultracapacitor. The operation of an ultracapacitor is often derived from a circuit model comprising an ideal capacitor in series with a resistor with a resistance value equal to the ESR. In general, this yields a good approximation of actual capacitor operation.

In one method of measuring ESR, the method can start drawing a discharge current from a resting (not charging or discharging with significant current) capacitor. During a time interval in which the change in voltage presented by the capacitor due to a change in the charge stored in the capacitor is small compared to the measured change in voltage, the measured change in voltage is substantially a reflection of the capacitor's ESR . Under these conditions, the instantaneous voltage change presented by the capacitor can be taken as an indicator, through calculation, of the ESR.

For example, upon initiation of the discharge current draw from the capacitor, it can be presented as the instantaneous voltage change DeltaV over the measurement interval DeltaT. As long as the capacitance of capacitor C discharged by a known current I during the measurement interval DeltaT yields a small voltage change compared to the measured voltage change DeltaV, an approximation to ESR can be obtained by dividing DeltaV by the discharge current I during the time interval DeltaT have. When I is measured in amps and DeltaV in volts, the ESR result will be in ohms.

Both ESR and capacitance can vary with ambient temperature. Thus, the relevant measurement may require the user to place the ultracapacitor 10 at a particular ambient temperature of interest during the measurement.

Performance requirements for leakage current are usually defined by environmental conditions typical for a particular application. For example, for a capacitor with a volume of 20 ml, the practical limit on leakage current may drop below 100 mA.

The nominal value of the normalized parameter may be obtained by multiplying or dividing the normalized parameter (eg, volumetric leakage current) by a normalizing characteristic (eg, volume). For example, the nominal leakage current of an ultracapacitor having a volume leakage current of 10 mA/cc and a volume of 50 cc is 500 mA, which is the product of the volume leakage current and the volume. On the other hand, the nominal ESR of an ultracapacitor having a volume ESR of 20 mOhm·cc and a volume of 50 cc is 0.4 mOhm, which is the quotient of the volume ESR and volume.

iv. Testing of Filling Effect for Ultracapacitors Containing AES

Also, to show how the filling process affects the ultracapacitor 10, two similar embodiments of the ultracapacitor 10 were constructed. One filled without vacuum, the other filled with vacuum. The electrical performance of the two examples is provided in Table 11. By repeated performance of such measurements, it has been found that an increase in performance is realized by filling the ultracapacitor 10 in vacuum. In general, it has been determined that it is desirable for the pressure in the housing 7 to decrease below about 150 mTorr, and more specifically below about 40 mTorr.

To evaluate the effectiveness of the vacuum filling technique, two different pouch cells were tested. The pouch cells comprised two electrodes 3 , each electrode 3 based on a carbonaceous material. Each of the electrodes 3 was disposed opposite to each other and facing each other. Separators (5) were placed between them to prevent short circuits and everything was submerged in electrolyte (6). Four measurement points were provided using two external taps. The separator 5 used was a polyethylene separator 5, and the cell had a total volume of about 0.468 ml.

C. Methods of using ultracapacitors

The present invention is also intended to include any and all users of, for example, ultracapacitors, eg, energy storage devices, disclosed herein. This may include the direct use of ultracapacitors or the use of ultracapacitors in other devices for any application. Such uses are intended to include making, offering for sale, or providing to users.

For example, in one embodiment, the present invention provides a method of using, for example, a high temperature rechargeable energy storage device (HTRESD), such as an ultracapacitor, comprising a HTRESD comprising an enhanced electrolyte system (AES). obtaining a; and maintaining the voltage constant across the HTRESD, such that the HTRESD exhibits an initial peak power density of 0.01 W/liter to 150 kW/liter, such that the HTRESD operates at ambient temperatures ranging from about -40°C to about 210°C. , alternately charging and discharging the HTRESD at least twice to cycle it. In certain embodiments, the temperature range is from about -40°C to about 150°C; about -40°C to about 125°C; about 80° C. to about 210° C.; about 80° C. to about 175° C.; about 80° C. to about 150° C.; or from about -40°C to about 80°C. In certain embodiments, HTRESD is

It exhibits an initial peak power density of about 0.01 W/liter to about 10 kW/liter, such as about 0.01 W/liter to about 5 kW/liter, such as about 0.01 W/liter to about 2 kW/liter.

In another embodiment, the present invention provides a method of using an ultracapacitor, wherein the method provides a volume leakage current (mA/cc) of less than about 10 mA/cc while maintained at a substantially constant temperature within a range of about 100°C to about 150°C. ), obtaining the ultracapacitor of any one of claims 1-85; and holding the voltage constant across the ultracapacitor such that the ultracapacitor exhibits an ESR increase of less than about 300 percent after 20 hours of use while the ultracapacitor is maintained at a substantially constant temperature within the range of about -40°C to about 210°C. and alternately charging and discharging the capacitor at least two times. In certain embodiments, the temperature range is from about -40°C to about 150°C; about -40°C to about 125°C; about 80° C. to about 210° C.; about 80° C. to about 175° C.; about 80° C. to about 150° C.; or from about -40°C to about 80°C.

In another embodiment, the present invention provides a method of providing a high temperature rechargeable energy storage device to a user; The method comprises an initial peak power density of 0.01 W/liter to 100 kW/liter, and at least 1 hour, such as at least 10 hours, when exposed to ambient temperature in a temperature range of about -40°C to about 210°C; For example at least 50 hours, such as at least 100 hours, such as at least 200 hours, such as at least 300 hours, such as at least 400 hours, such as at least 500 hours, such as selecting, for example, a high temperature rechargeable energy storage device (HTRESD) comprising an enhanced electrolyte system (AES) that exhibits a durability cycle of at least 1000 hours; and delivering the storage device so that the HTRESD is provided to the user.

In another embodiment, the present invention provides a method of providing a high temperature rechargeable energy storage device to a user; 86. The method of any one of claims 1-85, wherein the method exhibits a volumetric leakage current (mA/cc) of less than about 10 mA/cc while maintained at a substantially constant temperature within the range of about -40°C to about 210°C. obtaining an ultracapacitor of one term; and delivering the storage device so that the HTRESD is provided to the user.

INCLUDING BY REFERENCE

All contents of all patents, published patent applications and other references cited herein are expressly incorporated herein in their entirety.

equivalents

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, multiple equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of the present invention and covered by the following claims. Moreover, any numerical range or alphabetic range provided herein is intended to include both the lower value and the upper value of that range. Also, in at least one embodiment, any listings and groupings are intended to represent a shorthand or convenient way of recounting independent embodiments; Accordingly, each member of the list should be considered as an independent embodiment.

It should be appreciated that the teachings herein are merely exemplary and not limiting of the invention. In addition, those skilled in the art will recognize that additional components, configurations, arrangements, and the like may be realized while remaining within the scope of the present invention. For example, the configuration of layers, electrodes, leads, terminals, contacts, feed-throughs, caps, etc. may be different from the embodiments disclosed herein. In general, the design and/or application of ultracapacitors using electrodes and components of ultracapacitors is limited only by the needs of the system designer, manufacturer, operator and/or user and the needs presented in any particular situation.

In addition, various other elements may be included and called upon to provide aspects of the teachings herein. For example, additional materials may be provided for additional embodiments in which combinations of materials and/or omissions of materials are used that are within the scope of the teachings herein.

While the invention has been described with reference to exemplary embodiments, it will be understood that other changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, it will be understood that many modifications will be made to adapt a particular instrument, situation, or material to the teachings of the present invention without departing from the essential scope thereof. Accordingly, it is intended that the present invention not be limited to the particular embodiment disclosed in the first contemplated mode for carrying out the present invention, but should be construed by the claims appended hereto.

Claims (23)

An ultracapacitor comprising an energy storage cell in a hermetically sealed housing and an enhanced electrolyte system (AES), wherein the cell is electrically coupled to a positive contact and a negative contact, wherein the ultracapacitor is capable of performance or configured to operate at temperatures over an operating temperature range without significant changes in durability, the hermetically sealed housing comprising a barrier disposed on a portion of an interior surface thereof, the hermetically sealed housing comprising at least a glass-to-metal seal including one,
The ultracapacitor is configured to operate at a temperature within a temperature range of -40°C to 125°C,
The electrolyte system comprises a mixture of an ionic liquid and an organic solvent, and the operating temperature range of the ultracapacitor is the same but higher than that of an equivalent ultracapacitor in which the electrolyte composition is replaced with an electrolyte comprising an ionic liquid without an organic solvent. A wide ultracapacitor. The method of claim 1 , wherein the barrier comprises at least one of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE). ultra capacitor. 2. The ultracapacitor of claim 1, wherein the barrier comprises a ceramic material. 4. The ultracapacitor of any preceding claim, wherein at least one of the electrodes comprises a carbon-based energy storage medium. 5. The ultracapacitor of claim 4, wherein the carbon-based energy storage medium comprises carbon nanotubes. The ultracapacitor of claim 5 , wherein the carbon-based energy storage medium further comprises at least one of activated carbon, carbon fiber, rayon, graphene, airgel, carbon cloth, and a plurality of forms of carbon nanotubes. . 4. The ultracapacitor of any preceding claim, wherein each electrode comprises a current collector. The ultracapacitor of claim 1 wherein the content of halide ions in the electrolyte system is less than about 1,000 ppm. 9. The ultracapacitor of claim 8, wherein the content of halide ions in the electrolyte system is less than about 100 ppm. 2. The method of claim 1 wherein the total concentration of metallic species in the electrolyte system is less than about 1,000 ppm, and wherein the metallic species consists of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. An ultracapacitor selected from one or more metals selected from the group. 11. The ultracapacitor of claim 10, wherein the metallic species is selected from one or more alloys of a metal selected from the group consisting of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. 11. The ultracapacitor of claim 10, wherein the metallic species is selected from one or more oxides of a metal selected from the group consisting of Cd, Co, Cr, Cu, Fe, K, Li, Mo, Na, Ni, Pb and Zn. 2. The ultracapacitor of claim 1, wherein the barrier comprises multiple layers of material. 14. The ultracapacitor of any one of claims 1-3 and 8-13, wherein the housing comprises a multilayer material. 15. The ultracapacitor of claim 14, wherein the multilayer material comprises a first material clad over a second material. 15. The ultracapacitor of claim 14, wherein the multilayer material comprises at least one of steel, tantalum and aluminum. 2. The ultracapacitor of claim 1, wherein the pin of the glass-to-metal seal provides one of the contacts. 2. The feed-through of claim 1, wherein said glass-to-metal seal is comprised of a material selected from the group consisting of iron-nickel-cobalt alloy, nickel iron alloy, tantalum, molybdenum, niobium, tungsten, and stainless type and titanium. Ultracapacitors that include (feed-through). The glass-to-metal seal of claim 1 , wherein the glass-to-metal seal comprises at least one selected from the group consisting of nickel, molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon and tungsten, and alloys thereof. An ultracapacitor comprising a body made of material. 20. The hermetic seal of any one of claims 1 to 3, 8 to 13, and 17 to 19, wherein the hermetic seal exhibits a leak rate of about 5.0x10 ^-6 atm-cc/sec or less. An ultracapacitor. 20. The hermetic seal of any one of claims 1 to 3, 8 to 13, and 17 to 19, wherein the hermetic seal exhibits a leak rate of about 5.0x10 ^-10 atm-cc/sec or less. An ultracapacitor. The ultracapacitor of claim 1 configured to operate at a temperature within a temperature range of about -40°C to about 150°C. The ultracapacitor of claim 1 configured to operate at a temperature within a temperature range of about -40°C to about 210°C.

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