NZ256329A

NZ256329A - Dry pre-unit for capacitor power pack: manufacturing method

Info

Publication number: NZ256329A
Application number: NZ256329A
Authority: NZ
Inventors: Keh Chi Tsai; Robert Randell Tong; James M Poplett; Alan Bruce Mcewen; Gary Eugene Mason; Mark Larry Goodwin; Ronald Lee Anderson; James Paul Nelson; Douglas Alan Cromack; David Wu
Original assignee: Pinnacle Research Inst Inc
Priority date: 1992-09-18
Filing date: 1993-09-17
Publication date: 1997-05-26
Also published as: AU681351B2; EP0662248A1; CN1096611A; WO1994007272A1; AU4927793A; NO951045D0; NO951045L; JPH08501660A; CN1127771C; EP0662248A4; CA2144657A1

Description

<div class="application article clearfix" id="description"> tit New Zealand No. 256329 International No. PCT/US93/08803 Priority Dat»(s):..AS.).3.l9.r?: . lUfclS.*. Complete Specification Filed: C4»a: (6) .BQlflAW.a&M P.O. Journal No: Ikk.ltet. NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: Energy storage device and methods of manufacture Name, address and nationality of applicant(s) as in international application form: PINNACLE RESEARCH INSTITUTE, INC., of 141-B Albright Way, Los Gatos, California 95030, United States of America A US covMyaa^oj j _ (FOLLOWED BY PAGE 1 A) WO 94/07272 PCT/US93/08803 25 6 3 2 9 1 /4" ■ ENERGY STORAGE DEVICE AND METHODS OF MANUFACTURE BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to an energy storage device, and more particularly to a bipolar double layer capacitor-type energy storage device, and to methods for manufacturing the same. Description of the Related Art Energy Storage Devices - There has been significant research over the years, relating to useful reliable electrical storage devices, such as a capacitor or a battery. Large energy storage capabilities are common for batteries; however, batteries also display low power densities. In contrast, electrolytic capacitors possess very high power densities and a limited energy density. Further, carbon based double-layer capacitors have a large energy density; but, due to their high equivalent series resistance (ESR), carbon electrodes have low power capabilities. It would therefore be highly desirable to have an electrical storage device that has both a high energy density and a high power density. A recent review by B.E. Conway in J. Electrochem. Soc.. vol. 138 (#6), p. 1539 (June 1991) discusses the transition from "supercapacitor" to "battery" in electrochemical energy storage, and identifies performance characteristics of various capacitor devices. D. Craig, Canadian Patent No. 1,196,683, in November 1985, discusses the usefulness of electric storage devices based on ceramic-oxide coated electrodes and 1 pseudo-capacitance. However, attempts to utilize this disclosure have resulted in capacitors which have inconsistent electrical properties and which are often unreliable. N.Z. PATENT OFFICE 27 NOV 1996 RECEIVED m 94/07272 PCT/US93/08803 25 6 329 2 These devices cannot be charged to 1.0 V per cell, and have large, unsatisfactory leakage currents. Furthermore, these devices have a very low cycle life. In addition, the disclosed packaging is inefficient. M. Matroka and R. Hackbart, US Patent No. 5,121,288, discusses a capacitive 5 power supply based on the Craig patent which is not enabling for the present invention. A capacitor configuration as a power supply for a radiotelephone is taught; however, no enabling disclosure for the capacitor is taught. J. Kalenowsky, US Patent No. 5,063,340, discusses a capacitive power supply having a charge equalization circuit. This circuit allows a multicell capacitor to be 10 charged without overcharging the individual cells. The present invention does not require a charge equalization circuit to fully charge a multicell stack configuration without overcharging an intermediate cell. H. Lee, et al. in IEEE Transactions on Magnetics. Vol. 25 (#1), p.324 (January 1989), and G. Bullard, et al., in IEEE Transactions on Magnetics. Vol. 25 (#1) p. 102 15 (January 1989) discuss the pulse power characteristics of high-energy ceramic-oxide based doubie-layer capacitors. In this reference various performance characteristics are discussed, with no enabling discussion of the construction methodology. The present invention provides a more reliable device with more efficient packaging. Carbon electrode based double-layer capacitors have been extensively developed 20 based on the original work of Rightmire, U.S. Patent No. 3,288,641. A. Yoshida et al., in IEEE Transactions on Components. Hybrids and Manufacturing Technology. Vol. CHMT-10, #1,P-100 - 103 (March 1987) discusses an electric double-layer capacitor composed of activated carbon fiber electrodes and a nonaqueous electrolyte. In addition, the packaging of this double-layer capacitor is revealed. This device is on the 25 order of 0.4-1 cc in volume with an energy storage capability of around 1-10 J/cc. T. Suzuki, et al., in NEC Research and Development. No. 82, pp. 118-123, July 1986, discloses improved self-discharge characteristics of the carbon electric double-layer capacitor with the use of porous separator materials on the order of 0.004 inches thick. An inherent problem of carbon based electrodes is the low conductivity of the 30 material resulting in a low current density being delivered from these devices. A second difficulty is that the construction of multicell stacks is- oat_done in a true bipolar 27 NOV 1936 WO 94/07272 PCT/US93/08803 3 electrode configuration. These difficulties result in inefficient packaging and lower energy and power density values. Additional references of interest include, for example: The state of solid state micro power sources is reviewed by S. Sekido in Solid 5 State Ionics, vol. 9, 10, pp. 777-782 (1983). M. Pham-Thi et al. in the Journal of Materials Science Letters, vol. 5, p. 415 (1986) discusses the percolation threshold and interface optimization in carbon based solid electrolyte double-layer capacitors. Various disclosures discuss the fabrication of oxide coated electrodes and the 10 application of these electrodes in the chlor-alkali industry for the electrochemical generation of chlorine. See for example: V. Hock, et al. US Patent No. 5,055,169 issued October 8,1991; H. Beer US Patent no. 4,052,271 issued October 4, 1977; and A. Martinsons, et al. US Patent no. 3,562,008 issued February 9, 1971. These electrodes, however, in general do not have the high surface areas required for an 15 efficient double-layer capacitor electrode. It would be useful to have a reliable long-term electrical storage device, and improved methods to produce the same. It would also be desirable to have an improved energy storage device with energy densities of at least 20-90 J/cc. Packaging of Energy Storage Devices - As mentioned above, there has been significant 20 research over the years regarding electrical storage devices of high energy and power density. The efficient packaging of the active materials, with minimum wasted volume, is important in reaching these goals. The space separating two electrodes in a capacitor or a battery is necessary to electronically insulate the two electrodes. However, for efficient packaging, this space or gap should be a minimum. It would therefore by 25 highly desirable to have a method to create a space separator or gap that is substantially uniform and of small dimension (less than 5 mil (0.0127 cm). A common way to maintain separation between electrodes in an electrical storage device with an electrolyte present (such as a battery or capacitor) is by use of an ion permeable electrically insulating porous membrane. This membrane is commonly 30 placed between the electrodes and maintains the required space separation between the two electrodes. Porous separator material, such as paper or glass, is useful for this •Ho 94/07272 PCT/US93/08803 25 6 3 4 application and is used in aluminum electrolytic and double layer capacitors. However, for dimensions below 1 or 2 mil (0.00254 to 0.00508 cm) in separation, material handling is difficult and material strength of the capacitor is usually very low. in addition, the open cross-sectional areas typical of these porous membrane separators 5 are on the order of 50-70%. Polymeric ion permeable porous separators have been used in carbon double layer capacitors as discussed by Sanada et al. in IEEE, pp.224-230, 1982, and by Suzuki et al. in NEC Research and Development. No. 82, pp. 118-123, July 1986. These type of separators suffer from the problem of a small open area which leads to 10 increased electrical resistance. A method of using photoresist to fill voids of an electrically insulating layer to prevent electrical contact between two electrode layers for use as a solar cell is disclosed by J. Wilfried in US Patent No. 4,774,193, issued September 27, 1988. A process of creating an electrolytic capacitor with a thin spacer using a 15 photosensitive polymer re*' solution is disclosed by Maruyama et al in US Patent No. 4,764,181 issued August 16,1988. The use of solution application methods described in a porous double-layer capacitor electrode would result in the undesirable filling of the porous electrode. Additional references of general interest include U.S. Patents 3,718,551; 20 4,052,271; and 5,055,169. All of the applications, patents, articles, references, standards, etc. cited in this application are incorporated herein by reference in their entirety. In view of the above, it would be very useful to have a method to produce a reliable small space separation between electrodes in electrical storage devices with a 25 large open cross-sectional area. It would be desirable to provide a reliable long term electrical storage device having both a high energy density and high power density and improved methods to produce the same. It would also be desirable to provide efficient packaging of an electrical storage device by reducing the gap between the anode and cathode, which produces the electrical resistaoce^theiuiiiuaRtf^^iicting [N. Z. ■br 1 . -4 electrolyte. — I 5 25 6 32 9 According to a first aspect of the invention there is provided a dry preunit for an energy storage device comprising: at least a first cell for storing energy, said first cell comprising, in combination: a. a first electrically conductive electrode; b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first predetermined distance; and c. first dielectric gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means having a centrally located opening are bonded together to form said first cell, and air filled gap is formed therebetween. According to a further aspect of the invention there is provided a capacitor preunit including at least a first cell, the capacitor comprising: a. a first electrically conductive electrode; b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first redetermined distance; and c. first dielectric peripheral gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means are bonded together to form the first cell, a fill gap is formed therebetween. According to another aspect of the invention there is provided a method for making a dry preunit comprising the steps of forming at least a first cell by: a. spacing apart a first electrically conductive electrode and a second electrically conductive electrode, by a first predetermined distance; and b. placing a first dielectric gasket means between_^aid first and second ? 4 FEB ^j&ow^d by page 5a) -5a- 25 6 32 9 electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means are bonded together to form said first cell, a fill gap is formed therebetween. According to a still further aspect of the invention there is provided a method for making a capacitor preunit comprising the steps of forming at least a first cell by: a. spacing apart a first electrically conductive electrode and a second electrically conductive electrode, by a first predetermined distance; and b. placing a first dielectric gasket means between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means are bonded together to form said first cell, a fill gap is formed therebetween. According to another aspect of the invention there is provided a , method of producing an array of substantially uniform microprotrusions on ia surface as a separator useful in the construction of single or multiple layer electrical charge storage devices, which method comprises: (a) obtaining an electrically insulating material which is essentially inert to eiecxroiyce conditions to produce a thixotrcpic composition oi between amoient temperature to about 75°C and ambient pressure; (b) obtaining a thin electrode material comprising a thin flat electrically conducting metal sheet center coated on one or both sides with electrically conducting carbon, porous metal oxide, porous mixed metal oxide or other porous coating and securing the fiat electrode in a suitable holder; (c) placing a thin flat screen or stencil having small openings over the flat thin electrode; (d) contacting the top exterior thin screen surface with the flowable composition of step(a) so that small portions of the composition extrude through the pattern and contact the exterior surface of the thin electrode and optionally penetrate the exterior surface of the porous electrode coating, when a squeegee is brought across the screen surface to cause contact of the screen with the electrode surface; (e) removing the thin electrode material from the flat screen or stencil and; (f) curing the applied material whereby the discrete microprotrusions essentially retain their shape and dimensions. (followed by page 5b) -5b- 25 6 32 9 According to another aspect of the invention there is provided the method according to claim 25, wherein in step (a) the support has second electrically conducting material on the perimeter edge surfaces, in step (b) the microprotrusions are on the surface of the second electrically conducting material, in step (c) the gasket material is a thermoplastic, in step (e) the end sheets are a thicker support material, in step (f) the gasket material is in excess to create a continuous integral sealed enclosure, in step (g) the stack is cooled to ambient temperature, and in step (h) the cord comprises a metal, ceramic, organic polymer or combinations thereof. BRIEF DESCRIPTION OF THE FIGURES The above and other features of the present invention and the manner of attaining them, will become apparent, and the invention itself will be best understood, by reference to the following description and the accompanying drawings, wherein: Figure 1 is a perspective view of the preunit 10a dry energy storage device which is constructed according to the present invention; (followed by page 6) WO 94/07272 PCT/US93/08803 6 Figure 1A is a perspective view of the electrolyte-filled energy storage device 10A of the present invention; Figure 2 is a cross-sectional view of the storage device of Figure 1 showing a removable cord 117A within the storage device, taken along line 2-2 thereof; 5 Figure 2A is another cross-sectional view of the storage device of Figure 1, taken along line 2A-2A thereof; Figure 3 is a schematic representation of an exploded view of the preunit of Figure 1, illustrating three cells; Figure 4 is a block diagram of the manufacture steps of the storage device 10 10A; Figure 5 is a top plan view of a porous coating layer with microprotrusions which forms a part of the storage device of Figures 1 through 4; Figure 6 is a diagrammatic illustration of a capacitive circuit, which is equivalent to the device 10A; 15 Figure 7 is a schematic representation of a screen printing method to produce microprotrusions on a coating layer used with the energy storage device according to the present invention; Figure 8 is a schematic representation of an electrode holder used in the manufacture method of Figure 7; 20 Figure 9 is a schematic representation of a method to photolithographically produce the microprotrusions according to the present invention; Figure 10 is a schematic isometric view of a pair of hot rollers used for laminating a photoresist to an electrode prior to photolithography; Figure 11 is a schematic isometric view of a mask placed over the photo 25 resist of Figure 10; Figure 12 is a schematic isometric view illustrating the exposure of unprotected portions of the photo resist of Figures 10 and 11; Figure 13 is a cross-sectional view of an electrode which forms a part of the energy storage device, taken along line 13-13 of Figure 3; and WO 94/07272 PCT/US93/08803 7 Figure 14 is a schematic cross-sectional view of two bipolar electrodes with the high surface area porous coating layer on the electrically conducting substrate forming one cell. Figure 15 is a schematic view of a frame used to hold thin support materials 5 during the dip coating process; Figure 15A is a schematic view of wire used in the frame of Figure 15. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Definitions The definitions of the following terms are not intended to be exclusive: 10 "Cord" refers to the thin strips of material included in the method of manufacture of the dry preunit. After initial heating, the removal of the cord produces the open fill ports. "Electrically conducting support material" refers to any electrically conducting metal or metal alloy, electrically conducting polymer, electrically conducting ceramic, 15 electrically conducting glass, or combinations thereof. Metals and metal alloys are preferred for producing stock units. The support material should have a conductivity of greater than about 10'4 S/cm. "Second electrically conducting material" (having a high surface area) refers to a porous electrode coating which may be of the same or different composition on 20 each side of the support material. Preferred metal oxides of the present invention include those independently selected from tin, lead, vanadium, titanium, ruthenium, tantalum, rhodium, osmium, iridium, iron, cobalt, nickel, copper, molybdenum, niobium, chromium, manganese, lanthanum, or lanthanum series metals or alloys or combinations thereof, and possibly containing additives like calcium to increase 25 electrical conductivity. "Electrolyte" refers to an ionically conductive aqueous or non-aqueous solution or material, which enables the dry preunit to be electrically charged. "Cab-O-Sil®" refers to silica filler available from Cabot Corporation of Tuscola, Illinois. A variety of sizes are available. WO 94/07272 PCT/US93/08803 8 "Epoxy" refers to the conventional definition of the product which is an epoxy resin mixed with a specific curing agent, usually a polyamine. or polyepoxide mixed with a polyamine curing agent. MYLAR® refers to a polyester of polyethylene terephthalate of DuPont, Inc. of 5 Wilmington, Delaware. It is usually commercially available in sheet form of varying thicknesses. "Metal oxide" refers to any electrically conducting metal oxide. "Mixed metal oxide" refers to an electrically conducting oxide compound of two or more metal oxides. 10 "Photoresist" is any photo curable material. Usually, it is an epoxide or acrylate or combinations thereof. "ConforMASK" is a negative working photopolymer available commercially from Dynachem of Tustin, California. This polymer should be used at 50% or less relative humidity. 15 Drv Preunit Energy Storage Device Referring now to the drawings, and ,nore particularly to Figures 1, 2 and 3 thereof, there is illustrated a dry preunit of energy storage device 10 which is constructed according to the present invention. The energy storage device is first an assembled dry preunit 10. After filling the present cells with an electrolyte, the 20 surface is heated to close and to fuse the exterior surface, to form device 10A which is then electrically charged. The device preunit 10 generally includes a plurality of cells, such as the cells 110, 112 and 114, which are formed, prepared, and stacked according to the teaching of the present invention. Figure 1A illustrates an assembled view of the 25 electrical storage device preunit 10A, formed of twelve superposed cells. It should however be understood to those skilled in the art, after reviewing the present specification that any different number of cells can be used. For simplicity of illustration, Figure 3 is an exploded view of the preunit 10, showing only three exemplary cells 110, 112 and 114. The cells have generally 30 similar design and construction, and therefore, only the cells 114 and 112 will be described in detail, in relation to Figures 2, 2A, 3 and 13. WO 94/07272 PCT/US93/08803 9 The cell 114 includes a first electrically conductive external electrode or end plate 111 A, and a second internal, electrically conductive bipolar electrode 111B. Both electrodes 111A and 111B are spaced apart at the edges by means of two dielectric or electrically insulating gaskets 121 and 123. 5 When the first and second electrodes 111A and 111B, and the insulating gaskets 121 and 123 and the electrically conducting porous material (oxide) layers 119 and 120 are bonded together to form the cell 114, a central air filled gap 130 (Figure 2A) is formed by these elements. When the preunit 10 is ready to be used, the gap 130 is filled with an electrolyte (not shown! to produce device 10A. 10 For this purpose, an exemplary access or fill port 122, is shown in Figure 2A for illustration purpose only, and is formed between the gask *ts 121 and 123, in order to allow the electrolyte to fill the gap 130. The fill port 122 is formed by means of a tab or cord 117A, which is inserted between the gaskets 121 and 123, prior to fusing or bonding the gaskets 121 and 123. Whan the gaskets 121 and 15 123 are heated, the cord 117A becomes surrounded by the reflow gasket material, which causes the outline of fill port 122 to be formed. The two gaskets become a fused polymer mass covering a minimum of the active electrically conducing coating layers 119 and 120. Considering now the electrodes 111A and 111B in greater detail, the 20 methods of manufacturing them will be described later. One difference between the electrodes 111A and 111B is that the electrode 111A optionally includes a tab 160A, for connection to a power source (not shown). A further, but optional distinction between the electrodes 111A and 111B, is that the electrode 111A includes one porous electrically conductive coating layer 25 119, which is deposited on a support material or structure 116, while the bipolar electrode 111B includes two porous coating layers 120 and 131, which are deposited on either or both sides of the support material or structure 111B. As such, the electrode 111B is a true bipolar electrode. It should be understood that both sides of the electrode 111A could be coated with porous electrically conductive 30 layers. WO 94/07272 PCT/US93/08803 10 Yet another optional distinction between the electrodes 111A and 111B lies in the rigidity of the support structures 111A and 111B. The electrode 111 A, acting as an external end plate, should preferably have a more rigid construction, so that it imparts sufficient rigidity to the overall structure of the energy storage device 10A. 5 The electrode 111B and other similar internal electrodes do not necessarily need to be as rigid as the external electrode 111A. Nonetheless, when the device 10A is large, additional support structure is required, and the internal electrodes, i.e. 111B, are used as additional support structure. In this case, it is desirable to rigidify the internal electrodes, i.e. 111B. 10 As a result, the support material 116 is thicker than the support material 118. In the preferred embodiment, the support material 116 has a thickness of about 10 mils (0.0254 cm),while the support material 118 has a thickness of about 1 mil (0.00254 cm). Other values could alternatively be selected. The electrodes 111 A, 111B and the remaining electrodes of the storage 15 device 10A, are sized and dimensioned according to the desired application, without departing from the scope of the invention. For instance, in one application, the device 10A is miniaturized, e.g. for a cardiac defibrillator. Wh.ie in another application, the overall volume of the device is one cubic meter or even greater, e.g. for an electric vehicle. The dimensions of the electrodes determine the overall 20 capacitance of the storage device 10A. In the preferred embodiment, the electrodes, i.e. 111A and 111B, are rectangularly shaped. However, these electrodes and consequently the preunit 10 could assume various other shapes, such as circular, square, etc. An important feature of the preunit 10 is the flexibility of its design, which enables it to be used in 25 various applications. Considering now the coating layers 119 and 120 in greater detail, the methods of forming them will be described later. In the preferred embodiment, the coating layer 119 includes a plurality of microprotrusions, while the coating layer 120 does not include such microprotrusions. It should be understood, however, that 30 the coating layer 120 could alternatively be designed similarly to the coating layer 119, without departing from the scope of the invention. WO 94/07272 PCT/US93/08803 11 Figure 5 is a top plan view of the coating layer 119, which includes an array of microprotrusions, and which is deposited on the inner face or flat side of the support material 116. The coating layer 119 is porous with high surface area, electrically conductive, and relatively thin. The array includes two sets of 5 microprotrusions. The first set includes a plurality of peripheral microprotrusions 125, and the second set includes a plurality of centrally located microprotrusions 127. In the preferred embodiment, the peripheral and the central protrusions 125 and 127 are similarly designed, and are generally semi-spherically shaped. However, 10 other shapes, for example a rectangular shape, are contemplated within the scope of the present invention. The diameter of each protrusion 125 or 127 is about 6 mil (0.01524 cm). Different applications of the device 10 might require that the microprotrusions 125 and 127 be differently designed. The center-to-center separation of the peripheral microprotrusions 125 is about 20 mil (0.0508 cm), while 15 the center-to-center separation of the central microprotrusions 127 is about 40 mil (0.1016 cm). One reason for the higher density of the peripheral microprotrusions 125, is to prevent edge shorting. One reason for the lower density of the central microprotrusions 127, is to provide separation between the electrodes 111A and 20 111B, with minimal masking of the electrode surfaces. For this purpose, the gasket 121 is allowed to cover at least part of the microprotrusions 125, but preferably not the microprotrusions 127. The peripheral microprotrusions 125 are adjacently disposed along an outer periphery of the coating layer 119. While only four rows of microprotrusions are 25 illustrated, it should be understood to those skilled in the art, that additional rows may added, depending on the size and application of the device 10. The central microprotrusions 127 are similarly adjacently disposed, in an arrayed arrangement, within a central section 132 of the coating layer 119. As illustrated in Figure 5, the central microprotrusions 127 are surrounded by the peripheral microprotrusions 125. 30 The microprotrusions 125 and 127 are formed on the coating layer 119 to provide added structural support to the first and second electrodes 111A and 111B. WO 94/07272 PCT/US93/08803 12 For instance, if, the second electrode 111B starts to sag or bow toward the first electrode 111 A, the microprotrusions 127 will prevent contact between these electrodes 111A and 111B. Figure 5 further shows that the coating layer 119 further includes a plurality 5 of spacings, i.e. 133A through 133G, where the cord, i.e., 117A, are placed, in order to ultimately form the fill port, i.e. 122. As illustrated for large electrode sizes the coved only extends partway into the central section 132. For smaller electrode sizes the coved across the electrode surface with the two ends protruding out opposite sides, thus forming simultaneously fill ports 113C and 133D. In this case 10 the width of the cord is smaller than, or equal to the center-to-center separation between the central microprotrusions 127. However, the cord is larger than the center-to-center separation between the peripheral microprotrusions 125, to prevent the peripheral microprotrusions from pinching the cord, and preventing it from being removed the spacings are increased in the peripheral microprotrusions. Alternatively, 15 the cord may be similar in width to the peripheral microprotrusions separation and no accommodation in the microprotrusion pattern needs to be done. Considering now the coating layer 120, it serves a similar function as the coating layer 119, and is deposited on the side of the electrode 111B, which faces the inner side of the first electrode 111A. In the preferred embodiment, the coating 20 layer 120 does not include microprotrusions. In an alternative embodiment of the preunit 10, the coating layers 119 and 120 are similarly constructed, and include microprotrusion layers. Considering now the gaskets 121 and 123, the methods of producing them will h3 described later. The gaskets 121 and 123 are generally identical, and are 25 arranged in registration (adjacent and superposable) with each other. For brevity, only the gasket 121 will be described in greater detail. The gasket 121 includes a solid peripheral section 143 and a hollow central section 144. In the preferred embodiment, the cord 117A, or a part thereof, is placed between the gaskets 121 and 123, and extends across the hollow section, i.e. 144, 30 of the gaskets, and protrudes outside the peripheral section, i.e. 143. In another embodiment, the cord does not extend across the entire width of the gaskLts, and WO 94/07272 PCT/US93/08803 13 only a part of the cord is sandwiched between the gaskets and extends beyond both edges of one side of the gasket. Turning now to Figure 1, the next adjacent cell 112 will now be briefly described. The cell 112 is generally similar in design and construction to the cell 5 114. The cell 112 includes the bipolar electrode 111B, as its first electrode, and a second bipolar electrode 111C. The electrodes 111B and 111C are generally identical, and are spaced-apart, in registration with each other. A porous coating layer 131, which is identical to the coating layer 119, is deposited on the surface of the support material 118, facing the electrode 111C. A 10 coating layer 133, which is similar to the coating layer 120, is deposited on a support material or structure 140, which forms a part of the electrode 111C. The cell 112 further includes two gaskets 135 and 137 that are identical to each other and to the gaskets 121 and 123 of the cell 114. A cord 117B forms a fill port 142 between the gaskets 135 and 137. 15 The cell 110 is substantially similar to the cell 114, and includes a first bipolar electrode 111Y, a second electrode 111Z, two gaskets 157 and 159, a cord 117C, a tab 160, and a fill pert 162. It should be noted that Figure 3 does not show the inner electrode 111Y. Turning now to Figure 6, there is illustrated a diagrammatic view of a 20 capacitive circuit 200 which is representative of, and generally has an equivalent function to the device 10A. The circuit 200 illustrates the cell 114 as two capacitors C1 and C2; the cell 112 as two capacitors C3 and C4; and the cell 110 as two capacitors C5 and C6. As a result, the device 10 is generally equivalent to a plurality of capacitors connected in series. 25 The porous electrically conducting coating 119 in conjunction with an ionically conducting medium (not shown) within the cell 114, form the capacitor CI. The ionicaliy conducting medium and the coating 120 form the capacitor C2. The coating 131 and the ionically conducting medium within the cell 112 form the capacitor C3. The ionically conducting medium within the cell 112 and th« costing 30 133 form the capacitor C4. Similarly, the cell 110 is represented by the capacitors C5 and C6. WO 94/07272 PCT/US93/08803 14 An important aspect of the present invention, is the bipolar configuration of the energy storage device. The use of a single electrode, such as the electrode 111B to form two back-to-back capacitors, such as the capacitors C2 and C3, result in a bipolar electrode B. This design significantly reduces the overall size of the 5 device 10A. While not wanting to be bound by theory, an explanation of the operation of the capacitive energy storage device, at the molecular level is helpful to understand the enormous value of the electric double layer. For simplicity, to describe Figure 14, Figure 3 can be used for reference where the same reference numbers are used 10 (and the porous material is a mixed metal oxide). Figure 14 is a schematic cross-sectional representation of the magnified edge of the magnified edge of the support 118 & 148A and electrically conducting coating layers (120, 131, 133, 133B). The center support 188 is depicted as a metal but can be any material which 15 is electrically conducting and provides the support for the coating. The coating which has high surface area provides the structure and geometry for the energy storage. As can be seen in Figure 14, layer 120, etc. has a discontinuous surface with many fissures, micropore and mesopore which create the high surface area. Thus, the porous coatings 120 and 131 are coated onto support 118 to 20 form bipolar electrode 111B and coatings 133 and 133B are coated onto support 148A to form bipolar electrode 111C. After the preunit 10 is assembled, the pull tabs are removed creating the fill ports and the preunit 10 is charged with electrolyte 190, the fill ports, e,g. 117D, are sealed creating device 10A. The device : OA is then charged electrically producing the following results at 25 the same time: Coating 120 becomes negatively charged. Electrically conducting support 118 conducts electrons accordingly. Thus, porous coating 131 becomes positively charged. The ionically conducting electrolyte ions accordingly. An electric double layer is formed at the electrode-electrolyte interface forming the individual capacities 30 in circuit 200. Thus, the surface of coating 133 becomes negatively charged, and the surface of coating 133B becomes positively charged. Because the porous high WO 94/07272 PCT/US93/08803 15 surface area oxide allows the effective surface area of the electrode to become very high, the corresponding electrical storage capacity of the device increases dramatically. Methods of Manufacturing the Energy Storage Device 5 Referring to Figures 1 to 5, a general description for the preferred method to produce the dry pre-unit 10 of the energy storage device 10A, is as follows: (A) Support Material Preparation The support material are optionally etched or cleaned by a variety of conventional pickling and cleaning procedures. 10 In some experiments, if the metal surface is not etched it is too smooth. This smooth surface sometimes causes inadequate adhesion of the porous coating. The etch creates a suitable rough surface. 1. Wet Etching - A preferred procedure is to contact the metal support with an aqueous inorganic strong acid, e.g. sulfuric acid, hydrochloric acid, 15 hydrofluoric acid, nitric acid, perchloric acid or combinations thereof. The etching is usually performed at elevated temperatures of 50 to 95*C (preferably 75*C) for about 0.1 to 5 hr (preferably 0.5 hr) followed by a water rinse. Room temperature acid etching is possible. An alkaline etch or an oxalic acid etch may also used. 2. Dry Etching - The roughened support surface is obtained by sputtering, 20 plasma treatment, and/or ion milling. A preferred procedure is Ar RF sputter etching at between around 0.001 and 1 torr with about 1 KeV energy at 13.5 Mhz. Commonly, 0.1-10 watts/cm2 power densities for about 1-60 min. are used to clean and roughen the surface. Another procedure is to plasma etch the support with a reactive gas such as oxygen, tetrafluoromethane, and/or suifurhexafluoride at around 25 0.1-30 torr for about 1-60 min. 3. Electrcchemical Etching - The roughened surface is obtained by electrochemical oxidation treatment in a chloride or fluoride solution. (B) Coating of Support Material The coating (e.g. oxide) is porous and composed of mostly micropores 30 (diameter< 17^). Large 0.1-1//m wide cracks are present on the surface protruding to depths as thick as the coating. However, greater than 99% of the surface area WO 94/07272 PCT/US93/08803 16 arises from these micropores. The average diameter of these micropores are around 6-12 A. After various post-treatments the pore structure can be altered to increase the average pore size. For example, the steam post-treatment creates a bimodal 5 pore distribution. In addition to the micropores, a narrow distribution of mesopores (diameter< 17-1OOOA) having a diameter of about 35 A is created. These treated electrode coatings have 85-95% of the surface area arising from the micropore structure. With alternate electrode construction methods this pore size distribution can 10 be varied. The effective high surface area of the coating is 1,000 to 10,000 to 100,000 times larger than the projected surface area of the electrode as a monolith. The pore size, distribution, and surface area controlled with the temperature of pyrolysis and/or high temperature water treatment. In addition, the use of surfactants to create micelles or other organized structure in the coating solution 15 increases the average pore size up to the values around 100-200 A with only 5-10% of the surface area coming from micropores. As illustrated in Figure 13, the electrode 111A includes a porous and conductive coating layer 119, which is formed on at least one surface of the support material 116. The support material 116 is electrically conductive, and sufficiently 20 rigid to support the coating layer 119 and to impart sufficient structural rigidity to the device 10. One goal of the present invention, is to optimize the energy density and power density of the device 10. The object is achieved by reducing the thickness of the support material 116, and maximizing the surface area of the coating layer 119. 25 The power density of the device 10 is further optimized, by maintaining a low resistance. The surface area of the coating layer 119 is determined by the BET methodology, which is well known in the art. The surface enhancement, which is an indication of the optimization of the surface area of the coating layer 119, is 30 determined according to the following equation: Surface enhancement = (BET Surface Area / Projected Surface Area) WO 94/07272 PCT/US93/08803 17 In the present invention, the surface enhancement values can be as large as 10,000 to 100,000. The coating layer 119 is porous, and its porosity could range between about five percent (5%) and ninety-five percent (95%). Exemplary porosity range for 5 efficient energy storage is between about twenty percent (20%) and twenty-five percent (25%). In conventional double-layer capacitors, the main device resistance is due to the carbon coating layer. In the present invention, most of the device resistance is due to the electrolyte, which has a higher resistance than that of the porous 10 conductive coating layer. When the preunit device 10 is filled with an electrolyte, it becomes ready to be charged to become device 10A. The main criterion for the electrolyte is to be ionically conductive and have bipolar characteristics. The boundary or interface region between the electrode and the electrolyte is referred to in the field, as the 15 "double layer", and is used to describe the arrangement of charges in this region. A more detailed description of the double layer theory is found in "Modern Electrochemistry", by Bockris et al, volume 2, sixth print, chapter 7 (1977). The surface area of the coating layer affects the capacitance of the device 10A. If for instance, the surface enhancement factor is between 1,000 to 20,000, 20 and the double layer capacitance density is between about 10 to 500 microfarad per cm2 of the interfacial surface area (i.e. the BET surface area), then surface enhancement capacitance densities of about 0.1 to 10 farads/cm2 electrode are obtained. While the double layer theory is described herein, it should be understood that 25 other theories or models, such as the proton injection model, could alternatively be used. The high surface area (porous) electrically conducting coating material is applied onto the support material. 1. Solution Methods - The porous coating material may originate from 30 various reactive precursors in a solution or a sol-gel composition. Numerous methods of application of these precursor compositions are feasible; but not limited WO 94/07272 PCT/US93/08803 18 to the following. A curing, hydrolysis and/or pyrolysis process usually is performed to form the coating on the support. Pyrolysis of the metal salts is usually done in a controlled atmosphere (nitrogen, oxygen, water, and/or other inert and oxidative gasses) by means of a furnace and/or an infrared source. 5 (a) Dip Coating - The electrode or support, is dipped into a solution or sol-gel, coating the support with a precursor coating, and subsequently cured by pyrolytic and other methods. Optionally, this process may be repeated to increase layer thickness. A preferred procedure is to dip the support material in a metal chloride/alcohol solution followed by pyrolysis at between about 250 and 500 °C for 10 5-20 min in a 5-100% oxygen atmosphere. This process is repeated until the desired weight of coating is obtained. A final pyrolysis treatment at 250-450 *C is done for 1-10 hr. Typically about 1-30 mg/cm2 of coating is deposited onto a support for a capacitance density of around 1 -10 F per square centimeter electrode cross-sectional area. Another procedure is to 15 create a sol-gel solution with ruthenium, silicon, titanium and/or other metal oxides and coat the support as above. By adjusting the pH, water concentration, solvent, and/or the presence of additives like oxalic acid, formamide, and/or surfactants the discharge frequency characteristics of the coating may be adjusted. High relative humidity during the pyrolysis step can be used to complete the 20 conversion of starting material to oxide at lower temperatures, a procedure is to pyrolyze at about 300°C without control of humidity. However, an additional procedure is to maintain the relative humidity above about 50% during this pyrolysis at temperatures below 350°C or below. A preferred method for dip coating thin (e.g. 1 mil) support structures is to 25 use a wire frame structure 300 to keep the support material 118 under tension (Figures 15 and 15A). The wire frame structure 300 includes at least two (2) wires 301 and 301A of lengths larger than the width of the support material 118. Each wire 301 and 301A includes a single length of wire which is tightly coiled at each end about 360° 30 to form two coils 302 and 303. The coils are wrapped so the ends of the coil are around 1 cm above the plane of the wire. The coils 302 and 303 are placed through WO 94/07272 PCT/US93/08803 19 holes 304 and 305, respectively, in the support materials. The holes 304 and 305 are located at two corners on an adjacent side of the support material. Two additional wires 301B and 301C could be similarly used on the remaining two sides of the support material to provide additional support. 5 (b) Spray Coating - The coating solution is applied to the support by a spray method, cured, and optionally repeated to increase the thickness. A preferred procedure is to apply the coating solution to the substrate at a temperature of 0-150"C by means of an ultrasonic or other spray nozzle with a flow rate of around 0.1-5 ml/min in a carrier gas composed of nitrogen, oxygen and/or other reactive and 10 inert gases. The coating characteristics can be controlled by the partial pressure of oxygen and other reactive gasses. (c) Roll Coating - The precursor coating is applied by a roll coating methodology, cured, and optionally repeated to increase the thickness. The coatings described above for dip coating are usable here. 15 (d) Spin Coating - A spin coating methodology in the conventional art is used to apply the precursor coating, and optionally repeated. (e) Doctor Blading - A doctor blading methodology is used to apply the precursor coating, and optionally repeated. 2. Electrophoretic Deposition - The porous coating or precursor coating is 20 applied to the support by electrophoretic deposition techniques, and optionally repeated. 3. Chemical Vapor Deposition - The porous coating or precursor coating may be applied by chemical vapor deposition techniques known in the art. (C) Electrode Pretreatment 25 It has been found that a number of pretreatments (conditioning) or combinations thereof are useful to improve the electrical characteristics of the coating (e.g. electrochemical inertness, conductivity, performance characteristics, etc.). These treatments include for example: 1. Steam - High temperature water or steam treatment controlled in 30 atmospheres can be used to decrease the leakage current. A method procedure is to WO 94/07272 PCT/US93/08803 20 contact the coated electrode with water saturated steam in a closed vessel at between 150 and 325 *C for between 1 to 6 hr. under autogenic pressure. 2. Reactive Gas The coated electrode is contacted one or more times with a reactive gas such as oxygen, ozone, hydrogen, peroxides, carbon monoxide, 5 nitrous oxide, nitrogen dioxide, or nitric oxide at between ambient temperature and 300'C at a reduced pressure or under pressure. A preferred procedure is to contact the coated electrode with flowing ozone at between about 5-20 weight percent in air at between ambient and 100*C and 0.1-2000 torr pressure for 0.1-3 hr. 3. Supercritical Fluid - The coated electrode is contacted with a supercritical 10 fluid such as carbon dioxide, organic solvent, and/or water. A preferred procedure is treatment with supercritical water or carbon dioxide for 0.1-5 hrs by first raising the pressure then the temperature to supercritical conditions. 4. Electroohemical-The coated electrode is placed in a sulfuric acid electrolyte and contacted with an anodic current sufficient to evolve oxygen gas and 15 subsequently with a cathodic current. In one embodiment the electrode is contacted with 10mA/cm2 in 0.5M sulfuric acid for about 5 min, to evolve oxygen gas. The electrode is then switched to a cathodic current and the open circuit potential is driven back to a potential of between about 0.5V - 0.75V, preferably between 0.5 and 0.6 and more preferably about 0.5 V (vs. NHE) with out hydrogen gas evolution. 20 5. Reactive liquid-The coated electrode is contacted with an oxidizing liquid such as aqueous solutions of hydrogen peroxide, ozone, sulfoxide, potassium permanganate, sodium perchlorate, chromium (VI) species and/ or combinations thereof at temperatures around ambient to 100 *C for 0.1-6 hr. A preferred procedure uses a 10-100 mg/l aqueous solution of ozone at 20-50 *C for around 25 0.5-2 hr. followed by an aqueous wash. An additional procedure is to treat the coated electrode in a chromate or dichromate solution. (D) Spacing between Electrodes A number of methods are available to obtain electrical insulation and properly defined spacing between the electrodes. These methods include, for example: 30 1. Microprotrusions - The separator 125 and 127 between the coatings 119 and 120, includes a matrix of small (in area and height) protrusions, i.e. 125 WO 94/07272 PCT/US93/08803 21 and 127, on the surface of at least one side of the electrode. These microprotrusions may be composed of thermosets, thermoplastics, elastomers, ceramics, or other electrically insulating materials. Several methods of applying these microprotrusions are included, but not 5 limited to: (a) Screen Printing - The microprotrusions are placed on the electrode surface by conventional screen printing, as described below, in greater detail, under the heading "SCREEN PRINTING". Various elastomers, thermosets, photo curable plastics, and thermoplastics are applied in this way. A preferred procedure is to use 10 an acid resistant epoxy or VITON® solution. (b) Chemical Vapor Deposition - Microprotrusions are also placed on the electrode surface by depositing silica, titania and/or other insulating oxides or materials through a mask. (c) Photolithography - Microprotrusions are also produced by means of a 15 photolithographic methods, as is described later, in greater detail, under the heading "PHOTOLITHOGRAPHIC PRODUCTION OF MICROPROTRUSIONS". 2. Physically thin separator sheet - The separator between the electrodes is a thin, substantially open structure material such as glass. A preferred material is 0.001-0.005 in (0.00254 to 0.01270 cm) porous glass sheet available from 20 Whatman Paper Ltd located in Clifton, NJ. 3. Casting a separator - The separator between the porous material is also obtained by casting a thin, substantially open structure film such as for example NAFION®, polysulfones, or various aero- and sol-gels. 4. Air space - The separator between the electrodes is also an air space 25 which is subsequently occupied by the non-aqueous or aqueous electrolyte. (E) Gasketing The materials used for the gaskets, such as the gaskets 121,123, 135, 137, 157 and 159, at the edge of the active electrode surface include any organic polymer which is stable in the electrical/chemical environment, and to the processing 30 conditions. Suitable polymers include, for example polyimide, TEFZEL®, polyethylene (high and low density), polypropylene, other polyolefins, polysulfone, KRATON® WO 94/07272 PCT/US93/08803 22 other fluorinated or partly fluorinated polymers or combinations thereof. The gasket may be applied as a preformed mate il, screen printed, or by other methods. (F) Cord for Fill Port The cord (117A, 117B and 117C) for the creation of the fill ports, such as 5 thu fill ports 122 and 142, is of any suitable material having some specific properties, e.g., it is different from the gasket materials, has a higher melting temperature (Tm) than the gasket material, and does not melt, flow or adhere to the gasket material under the heating conditions described herein. Generally, glass, metal, ceramic, and organic polymers or combinations thereof are used. 10 (G) Stacking A stack is created by starting with an endplate and alternating gasket material, cord, electrode, gasket, cord electrode until the desired number of cells are created finishing with a second endplate, and optionally with a gasket material on the top outside of the stack. 15 (H) Assembling (heating and cooling) The stack is heated under pressure to cause reflow of the gasket material, adhering and sealing the perimeter of the electrode materials to the adjacent electrode in the stack; thereby, creating isolated cells and an assembled stack unit. This is done in an inert atmosphere. 20 (a) Radio Frequency Induction Heating (RFIH) is used to heat the stack to cause reflow of the gasket material. (b) Radiant Heating (RH) is used to uniformly heat the stack to cause reflow of the gasket material. A preferred method is to use 1-100 |/m radiation at 0.5-10 watts/cm2 for 1-20 min. 25 (c) Conductive and/or convective heating in a furnace, optionally in an inert atmosphere, is used to heat the stack to cause reflow of the gasket material. (I) Creating the fill port The cords are pulled to remove them from the assembled unit to create a dry preunit having at least one fill port per a cell. 30 (J) Post-Conditioning WO 94/07272 PCT/US93/08803 23 1. A number of post-conditioning reactive gas treatments of the stack or assembled stack or combinations thereof are useful to improve the overall and long term electrical characteristics of the electrode and resulting device. These include either before step (H) and/or after step (I) treatment with hydrogen, nitric oxide, 5 carbon monoxide, ammonia, and other reducing gasses or combinations thereof at between ambient temperature and the Tm of the gasket material at a reduced pressure or under pressure. 2. A second post conditioning commonly done is to adjust the open circuit potential of the electrode after step (F) and stack the electrode in an inert 10 atmosphere (e.g. Ar, N2). This is done by using a cathodic current without hydrogen evolution. (K) Filling of Dry Preunit The dry preunit is filled with an ionically conducting aqueous or non-aqueous electrolyte. 15 A preferred electrolyte is approximately 30% sulfuric acid in water due to the high conductivity. Non-aqueous electrolytes based on propylene and ethylene carbonate are also used to obtain larger than 1.2V/cell potentials. A preferred procedure for filling the dry preunit with liquid electrolyte is to place the preunit in a chamber, evacuate the chamber between about 1 torr to 1 20 microtorr, preferably about 250 mtorr to less than 1 torr, and introduce the electrolyte; thereby, filling the cell gaps with electrolyte through the fill ports. Alternatively, the preunit may be placed in the electrolyte and a vacuum pulled; thereby causing the gas in the cell gaps to be removed and replaced by the electrolyte. 25 In addition, non liquid based electrolytes (e.g. solid and polymer) may be used. In those cases the electrode is coated with the electrolyte before reflow and a fill port is not required. (L) Sealing of Fill Ports The fill ports are sealed by reflowing an additional film of polymer the same or 30 different over the openings to create a sealed device. This is commonly done with an induction heater, which locally heats the film over the fill port opening. WO 94/07272 PCT/US93/08803 24 (M) Burn-In The device is brought to full charge usually by charging the device in 0.1 V/cell steps at a charging current of about 4 mA/cm2. (N) Testing 5 Termination Methods -- Several methods are used to make electrical connections to the ultracapacitor endplates, and are described below. 1. Endplate Tabs (160 and 160A) - The endplates (111A and 1112) themselves have been cut to extend out beyond the normal gasket perimeter. These extensions allow attachment of a wire or ribbon. Typically, the extension is a stub 10 from which all oxide material is removed down to the bare support material; 5 mil (0.0127 cm) thick nickel ribbon is spot welded to the stub. 2. Silver Epoxy - The oxide coating is removed from the exposed faces of the endplates or the endplates may be coated only on one side. Clean nickel foil leads or copper plates make electrical connection to the exposed faces by bonding 15 them together with a conductive silver epoxy. Optionally, the oxide coating is present. 3. Lugs - Threaded titanium nuts are welded to the thick titanium endplates before coating. Electrical connection to the titanium nuts is achieved by screw attachment. 20 4. Press Contacts - The oxide is removed or the endplates may be coated only on one side from the exposed side of the endplates before assembly into the device stack. The bare support material e.g. titanium, is reverse sputtered to clean the surface, being careful not to overheat the substrate. The clean surface is then sputtered with titanium to lay down a clean adhesion layer, followed by gold. The 25 gold acts as a low contact resistance surface to which electrical contact can be made by pressing or by wire bonding. 5. Deposition of a compatible medium such for example aluminum, gold, silver, etc. outside by CVD or other means. The device resistance is measured at 1 kHz. The device capacitance is 30 determined by measuring the coulombs needed to bring the device to full charge at a WO 94/07272 PCT/US93/08803 25 charging rate of around 4 mA/cm2 of electrode area. Leakage current is measured as the current needed to maintain a full charge after 30 min. of charging. These devices may be made in various configurations depending on the desired application. By adjusting the device voltage, cell voltage, electrode area, 5 and/or coating thickness in a rational manner, devices made to fit defined and predetermined specifications are constructed. The electrode capacitance density (C' in units of F/cm2) is roughly 1 F/cm2 for every 10 /um of coating. Therefore, for large capacitance values a thicker coat is used. The device capacitance (C) is equal to the electrode capacitance density times 10 the electrode area (A in units of cm2) divided by two times the number of cells (n) (equation 1). The leakage current (i") is proportional to the electrode area, while the equivalent series resistance (ESR) is inversely proportional to the electrode area (eqn. 2). Typical values for i" are less than 20 //A/cm2. 15 The total number of cells in a device (n) is equal to the cell voltage (Vr) divided by the total device voltage (V) (eqn. 3). Cell voltages up to about 1.2 V can be used with aqueous based electrolytes. The device height (h), based on a cell gap (h') and a support thickness (h"), is determined from the number of cells and the electrode capacitance density in units 20 of cm by equation 4. The device ESR is a function of the number of cells times the cell gap (h') times the resistivity of the electrolyte (r) times a factor of about 2 divided by the area (equation 5). Devices are constructed to meet the requirements of various applications by 30 considering the voltage, energy, and resistance requirements. The following examples are not meant to be limiting in any way: 25 eqn. 1 eqn. 2 eqn. 3 eqn. 4 eqn. 5 C = C'A/2n i" a A a 1/ESR n = V/V' h/cm = n(0.002C'+ h' + h") ESR = 2nh'r/A WO 94/07272 PCT/US93/08803 26 For electric vehicle applications about a 100 KJ to 3 MJ device is used. A large voltage (about 100 to 1000 V) large energy (1-5 F/cm2) storage device is used with an electrode area of about 100 to 10,000 cm2. For electrically heated catalyst applications for reduction of automobile cold 5 start emissions about a 10 to 80 KJ device is used. This device is about 12 to 50 V constructed with around 100 to 1000 cm2 area electrodes of 1-5 F/cm2. Optionally, a device consisting of several devices in parallel can be constructed to meet the electrical requirements. For defibrillator applications about a 200-400 V device with 0.5 to 10 cm2 10 area electrodes of 1-3 F/cm2 are used. For uninterruptable power source applications various series/parallel device configurations may be used. Screen Printing Considering now a screenprinting method 250, with respect to Figures 7 and 15 8, the focus of the method 250, is to produce a series of microprotrusions 125 and 127 on the surface of the coating layers, to act as a space separator in electrical storage devices, such as a capacitor or a battery, in general, and in the dry preunit energy storage device 10, in particular. The substrate is usually a thin metal such as titanium, zirconium, or alloys 20 thereof. The substrate is usually in the shape of a thin metal plate as is conventional in the capacitor art. The substrate is coated on one or both sides with a porous carbon compound or a porous oxide coating. This step is accomplished by methods conventional in the art. The oxide coating serves as the charge storage area for the device. 25 Alternately, a stacked set of battery electrodes (e.g., lead for lead acid) or electrolytic capacitor electrodes (e.g., alumina and tantalum) may be fabricated. It is important that the flat surfaces of adjacent coated substrates or electrodes do not contact each other and further be of a uniform separation.. The epoxy microprotrusions accomplish the desired uniform separation. 30 Sample Holding -- The coated thin flat substrate needs to be secured (or held), so that the formation of the microprotrusions is precise and accurate on the WO 94/07272 PCT/US93/08803 27 flat surface of the substrate. For thin metal sheets (0.1 to 5 mil (0.000254 to 0.0127 cm), especially about 1 mil (0.00254 cm)) an electrode holder 275 is particularly important. If a strong vacuum is pulled on a thin sheet, often reverse dimples are formed in the thin sheet which cause significant undesirable changes in 5 the physical and electrical properties of the final device. The electrode holder 275 includes a porous ceramic holder 276, which is useful because the pore size is small enough that the dimples do not appear when a mild or stronger vacuum is pulled. The fiat ceramic surface of the ceramic holder 276 must be in intimate contact with the surface of the electrode 111 A, under 10 conditions which do not deform the metal or disrupt the coating present. The vacuum used with the porous ceramic is at least 25 in mercury. Preferably the vacuum is between about 25 and 30 in., especially 26 and 29 in. Further, the ceramic substrate needs to be flush with the surface of any mechanical holder to assure that uniform extrusion of the epoxy through the screen 15 openings occurs. Flush in this context means that the flat surface of the holder and the surface of the coating for electrical storage differ from each other by between about ± 5 mil (0.0127 cm) deviation or less from level per 6 linear in. The electrode holder 275 further includes a metal frame 277, which should also be as flush (flat) as possible so that uniformly sized protrusions are formed from 20 one end of the electrode to the other. The electrode holder 275 can be purchased from a number of commercial sources for example from Ceramicon Designs, Golden, Colorado. Alternatively, the sample holder 276 can be manufactured using commercially available metals, alloys or ceramics. 25 Usually, a 5 in (12.7 cm) by 7 in (17.78 cm) coated sheet electrode is formed. The metal holder 277 has a plurality of strategically located pins, such as the three pins 278, 279 and 280, which are used to align and position the electrode 111A, using a plurality of corresponding holes 281, 282 and 283, respectively. The 30 holes 281, 282 and 283 are usually as close to the peripheral edges of the electrode WO 94/07272 PCT/US93/08803 28 111A, as possible to conserve useful electrode surface. Alternatively, no alignment holes are used, and the pins are used to align the electrode edges. A stencil (not shown) having a predetermined open pattern, is stretched and secured in a conventional screen printing frame (not shown). The screen mesh is 5 removed. The epoxy components are mixed and the fluid epoxy is placed on the surface of the stencil, then spread to obtain an even applied coat. This can be accomplished using a pressure bar, doctor bar or a squeegee. Usually, constant temperature and humidity are important to obtain an even 10 coat. The stencil is then carefully removed leaving the fluid epoxy protrusions on the surface of the oxide. The epoxide protrusions are then cured using ambient, accelerated heat at from between 100 to 150°C. or light. The electrode having microprotrusions is then combined with other 15 electrodes, and assembled in a wet process or a dry process. If a dry process is used, the dry unit 10 is then back filled with electrolyte, when it is to be charged. It is important that the cured epoxy does not react with the liquid electrolyte eventually used in the fabrication of the capacitor having multiple layers of electrodes. 20 The cured microprotrusions then perform their function by keeping the spacing between the electrodes uniform. As can be seen from Figure 6, the edges of the flat surface of the electrode have protrusions 125 that are closer together than those protrusions 127 in the active or central portion of the electrode. These protrusions 125 increase the 25 support at the edges to maintain uniform separations. Alternatively, bars may be used. It is apparent that from these teachings the following are possible: Increasing or decreasing the substrate electrode thickness will allow an increase or decrease in the microprotrusion spacing due to changes in support 30 rigidity. WO 94/07272 PCT/US93/08803 29 Other thermosets, thermoelastomers, or photo curable epoxies or epoxy derivatives conventional in the art can be used. Other microprotrusion pattern elements can be used such as squares, lines, crosses, etc. Specifically, bars on the perimeter can add mechanical support. 5 Optionally the screen may be heated, if necessary to bring the resin flowable epoxy to a temperature when its viscosity becomes suitable for printing for a short time. This heating step followed by screen printing of the flowable epoxy resin must be performed quickly because the working time for the epoxy is significantly 10 reduced. The electrical storage devices produced having the microprotusions 125 and 127 are useful as batteries, capacitors and the like. Photolithographic Production of Microprotrusions The focus of the present method is to produce a series of microprotrusions on 15 the surface, or alloys of the electrode substrate, using photolithography, with respect to Figures 10, 11 and 12. The substrate is usually in the shape of a thin metal plate as is conventional in the capacitor art. A photo resist film 381 is applied to the surface of the electrode 111 A, either by vacuum lamination using the commercially available Dynachem ConforMASK film 20 applicator, and Dynachem vacuum applicator Model 724/730, or by passing the photo resist film 381 and electrode 111A through a pair of heated rollers 384 and 385. Exposure is done using a standard 1 -7kW UV exposure source, such as mercury vapor lamps 389. 25 The ConforMask film applicator is developed using standard conditions such as 0.5-1.0% sodium or potassium carbonate monohydrate in either a developing tank or a conveyorized aqueous developer. Optionally, after developing the electrode with microprotrusions may be neutralized in a dilute 10% sulfuric acid solution. This removes all the unwanted unreacted film to leave the reacted microprotrusions 30 adhered to the electrode surface. WO 94/07272 PCT/US93/08803 30 10 15 20 To obtain optimum physical and electrical performance properties the resulting material is put through a final curing process involving both UV irradiation and thermal treatment utilizing conventional UV curing units and convection air ovens. The multiple electrodes are assembled to produce for instance a capacitor, as described above. The microprotrusions accomplish the desired uniform separation. COMMERCIAL APPLICATIONS The energy storage device 10A has a multitude of applications, as a primary or back up power supply, and/or as a capacitor. The size is from 0.1 volt to 100,000 volts or 0.1cm3 to 10® cm3. Typical voltage ranges may include combinations of uses in automotive and other applications. Among these applications are the following: TYPICAL Automobile Applications 25 Airbags & Seat Restraints Seat Warmers 1-100 Electronically Heated Catalyst 1-1000 Electric Vehicle Propulsion 100-1000 Hybrid Electric Vehicle Propulsion 1 -1000 Internal Combustion/Ultra Capacitor Propulsion 1-1000 Power Steering 1-1000 Regenerative Braking/Shock Absorption 1-1000 Starting Lighting and Ignition with battery 1-1000 Starting Lighting and Ignition stand alone 1-100 TYPICAL Vplt RANQE SIZEIcm3) 1-100 1-1000 1-100 1-1,000,000 100-1,000,000 10-100,000 100-100,000 1-100 5-100 2-100 1-100 Medical Applications Cardiac Defibrillators Pacemakers 30 Neuro stimulators and like Implantable and external devices Surgical Power Tools 10-500 0.1-100 1-300 0.1-300 0.1-300 0.1-300 0.1-300 0.1-300 10-700 1-10 WO 94/07272 PCT/US93/08803 31 TYPICAL Medical Applications (cont) Volt RANGE Ambulatory Monitoring Equipment 1-100 5 Automatic Liquid Chromatography 1-100 Automated Clinical Lab Analysis 1-100 Computerized Tomography (CT) Scanners 1-1000 Dental Equipment 1 -200 Digital Radiography Equipment 1-500 10 Eiectrosurgical Instruments 1 -200 Fiberoptics 1-100 Examination Scopes 1-100 Hearing Aids 1-10 Infusion Devices 1-100 15 Magnetic Resonance Imaging (MRI) 1-1000 Nuclear Medical Diagnostic Equipment 1 -1000 Electric Patient Monitoring Systems 1 -200 Respiratory Therapy Equipment 1-50C Surgical Lasers 1 -1000 20 Electric Surgir3l Support Systems 1-100 Ultrasonic Diagnostic Equipment 1-100 Mobile Propulsion Systems Fork lifts 1-1000 Golf carts 1-1000 25 Farm Implements Trains Subways 1-1000 Regenerative Braking 1-1000 Business/Commercial Electronics Applications Calculators 1-120 Cellular Telecommunications 1-120 30 Commercial Audio Amplifiers 1-1000 Commercial Flash/Strobe Lights 1-1000 Commercial Power Tools 1-1000 TYPICAL glSEIcm3) 1-100 1-20 1-20 1-100 1-10 1-1000 1-10 1-100 1-10 0.1-1.0 0.1-10 1-1000 1-100 1-100 1-100 1-1000 1-1000 1-100 100-10,000 100-10,000 100-100,000 1-100 0.5-10 1-100 1-10 1-10 1-100 WO 94/07272 PCT/US93/08803 32 Business/Commercial Electronics (cont) Commercial Video Cameras Computers 5 Copiers Dictation Equipment Electric Motors Electronic Locks Electronic Organizers/PDAs 10 Emergency Lighting Systems Facsimile Equipment Microphones Pagers Printers 1 5 Security Systems Slide Projectors Uninterruptible Power Supplies Surge Protectors Wireless Networks 20 Consumer Electronics Applications Audio Systems: Compact/Home Portable Tape/CD Walkman/Personal Stereo 25 CB Radios HAM Radios Camcorders Home Satellite Dishes Microphones 30 Monitors and Cathode Ray Tubes Photo Flash TYPICAL Volt RANGE 1-120 1-120 1-120 1-100 1-1000 1-120 1-100 1-440 1-120 1-120 1-120 1-120 1-120 1-120 1-1000 1-1000 1-1000 1-120 1-120 1-120 1-120 1-120 1-120 1-120 1-120 1-1000 1-1000 TYPICAL SIZE(cm3) 1-10 1-10 1-10 1-1000 1-1000 1-10 1-5 1-1000 1-10 1-3 1-2 1-10 1-100 1-100 1-100,000 1-100,000 1-1000 1-10 1-5 1-5 1-10 1-100 1-10 1-10 1-3 1-100 1-3 WO 94/07272 PCT / US93/08803 33 10 TYPICAL TYPICAL Consumer Electronics Applications (cont) Volt RANGE SIZE(cm3) Receivers, Transceivers 1-1000 1-10 Telephone answering devices 1-120 1-5 Cellular, cordless phones 1-120 1-3 Toys & Games 1-120 1-10 Television sets 1-1000 1-10 Home 1-1000 1-10 Portable 1-1000 1-10 VCRs 1-120 1-10 Video Disk Players 1-120 1-10 Video Games 1-120 1-10 Watches/Clocks 1-120 1-100 Consumer Electric Housewares Applications 15 Air Purifiers 1-120 1-100 Bag Sealers 1-500 1-100 Blenders 1-120 1-10 Clocks-Total 1-120 1-100 Alarm & Desk 1-120 1-10 20 Coffee Grinders 1-120 1-10 Coffee Makers 1-120 1-10 Convection Ovens 1-1000 1-1000 Corn Poppers 1-120 1-10 Curling Irons/Brushes 1-120 1-5 25 Deep Fryers 1-230 1-100 Electric Blankets 1-120 1-10 Flashlights 1-100 1-10 Floor Polishers 1-220 1-100 Food Processors 1-120 1-10 30 Hair Dryers 1-120 1-5 Heating Pads 1-120 1-5 WO 94/07272 PCT/US93/08803 34 (Cont) TYPICAL TYPICAL Consumer Electric Housewares Applications Volt RANGE SIZE(cm3) Home Security Systems 1-120 1-100 Irons 1-120 1-5 5 Knives 1-120 1-3 Massagers 1-120 1-5 Mixers 1-120 1-5 Microwave Ovens 1-230 1-10 Power Tools 1-230 1 -100 10 Security Systems 1-230 1-100 Shavers 1-120 1-3 Smoke Detectors 1-120 1-5 Timers 1-120 1-3 Toasters/Toaster Ovens 1-120 1-5 15 Toothbrushes (Electric) 1-120 1-3 Vaporizers 1-120 1-10 Water Pulsators 1-120 1-10 Whirlpools (Portable) 1-120 1 -100 Consumer Maior Appliances 20 Compactors 1-120 1-10 Dishwashers 1-220 1-100 Dryers 1-120 1-100 Freezers 1-220 1-100 Ranges 1-220 1-1000 25 Refrigerators 1-120 1-100 Washers 1-220 1-100 Water Heaters 1-220 1-100 Outdoor Appliances Bug Killers 1-120 1-10 30 Outdoor Grills 1-120 1-100 Power Mowers 1-220 1-100 WO 94/07272 PCT/US93/08803 35 Outdoor Appliances (cont) Riding Mowers Riding Tractors Rotary Tillers Snow Plows/Blowers Weed Trimmers TYPICAL TYPICAL Volt RANGE SIZE(cm3) 1-1000 1-1000 1-1000 1-220 1-220 1-1000 1-10,000 1-10,000 1-1000 1-100 10 15 20 25 Other Applications Electro-expulsive Deicing Electronic Fuses Lasers Phased-Array radar Rail Gun 1-1000 1-1000 1-1000 1-1000 1-1000 1-100 1-10 1-100 1-1000 1-10,000 30 Multiple devices are placed is series and/or parallel for specific applications to achieve desired performance. Fabrication of Drv Preunit The following examples are presented to be descriptive and explanatory only. They are not to be construed to be limiting in any manner. EXAMPLE 1 Fabrication of A Drv Preunit (A) Coating Method The support structure is prepared by etching a 1 mil (0.00254 cm) titanium sheet with 35% HN03/1.5 % HF at 60 *C for 5 min. The end plates are 5 mil (0.0127 cm) titanium. The oxide coating solution is 0.2 M ruthenium trichloride trihydrate and 0.2 M niobium pentachloride in tert-butanol (reagent grade). The etched Ti sheets are dip-coated by immersion into the solution at ambient conditions. The coated sheet is submerged into the solution, held for about 1 sec and then removed. WO 94/07272 PCT/US93/08803 36 After each coating, the oxide is dried at 70 *C for 10 min, pyrolyzed at 350*C for 10 min and removed to cool to ambient temperature all in ambient atmosphere. The dip-coating steps are repeated for 10 coats (or any desired number) 5 rotating the Ti sheet so as to dip with alternate sides down. A thickness of about ten microns is achieved. The fully coated sheet is final annealed at 350'C for 3 hrs in ambient atmosphere. (B) Electrode Pretreatment 10 The coated electrode is contacted with saturated steam in a closed vessel at 280 *C for 3 hrs under autogenic pressure. (C) Spacing Microprotrusions are screen printed on one side of the electrode, as described below, in greater detail, under the heading "SCREEN PRINTING". The epoxy 15 compound is EP21AR from Masterbond, of Hackensack, New Jersey. The epoxy protrusions are cured at 150* C for 4 hr. in air. The coated electrodes are next die-stamped to the desired shape. (D) Gasket A modified high density polyethylene (HDPE, improved puncture resistance 20 and adhesion) 1.5 mil (0.00381 cm) thick by 30 mil (0.0762 cm) wide with outside perimeter the same as that of the electrode is placed on the electrodes on the same side as the microprotrusions and impulse heat laminated. The HDPE is grade PJX 2242 from Phillips-Joanna of Ladd, Illinois. (E) Cord 25 One cord (Dupont T2 TEFZEL® film 90ZM slit in machine direction) 0.9 mil (0.00229 cm) thick by 10 mil (0.0254 cm) wide is placed across the narrow dimension of the gasket and electrode surface and aligned between microprotrusions. The location of the cord is one of three positions centered, left of center, or right of center. 30 A second HDPE gasket is placed on the first gasket sandwiching the cord between the two gaskets. WO 94/07272 PCT/US93/08803 37 The second gasket is impulse heated to adhere to the first gasket and to fix the cord in place. (F) Stacking Electrode/microprotrusion/gasket/cord/gasket units are stacked in a non-5 metallic (ceramic) alignment fixture beginning with a 5 mil (0.0127 cm) end plate unit to the desired number of cells and ending with a plain 5 mil (0.0127 cm) end plate with the cords arranged such that the location is staggered-left, center, right in a three unit repeating cycle (end perspective). Light pressure is applied to the top of the stack through a ceramic piston block to maintain uniform alignment and contact 10 throughout the stack. (G) Reflow A radio frequency induction heater (2.5 kW) is used to heat the stack. The stack was placed centrally in the three turn, 3 in (7.62 cm) diameter coil and heated for 90 seconds at a power setting of 32 %. The fused unit is allowed to cool to 15 ambient temperature. (H) Cord Removal The cords are removed by carefully pulling the exposed ends of the cord to leave the open fill ports. EXAMPLE 2 20 Alternative Fabrication of Dry Preunit (A) Coating Method The support structure is prepared by etching a 1 mil (0.00254 cm) titanium sheet with 50% HCI at 75 *C for 30 min. The end plates are 2 mil (0.00508 cm) titanium. 25 The oxide coating solution is 0.3 M ruthenium trichloride trihydrate and 0.2 M tantalum pentachloride in isopropanol (reagent grade). The etched Ti sheets are dip-coated by immersion into the solution at ambient conditions. The coated sheet is submerged into the solution, held for about 1 sec and then removed. 30 After each coating, the oxide is dried at 70 *C for 10 min. in ambient atmosphere, pyrolyzed at 330*C for 15 min in a 3 cubic feet per hrs. flow of 50 vol. WO 94/07272 PCT/US93/08803 38 % oxygen and 50 % nitrogen, and removed to cool to ambient temperature in ambient atmosphere. The dip-coating steps are repeated for 30 coats (or any desired number) rotating the Ti sheet so as to dip with alternate sides down. 5 The fully coated sheet is final annealed at the above conditions for 3 hr. (C) Spacing VITON® microprotrusions are screen printed on one side of the electrode, as described below, in greater detail, under the heading "VII. SCREEN PRINTING". The VITON® protrusions are cured at 150'C for 30 min. in air. The coated 10 electrodes are next die-stamped to the desired shape. (D) Gasket A modified high density polyethylene (HDPE, improved puncture resistance and adhesion) 1.0 mil (0.00254 cm) thick by 20 mil (0.0508 cm) wide with outside perimeter the same as that of the electrode is impulse heat laminated to both sides 15 of the electrode. The HDPE is grade PJX 2242 from Phillips-Joanna of Ladd, Illinois. (E) Cord One cord, 1 mil (0.00254 cm) diameter TEFLON® coated tungsten wire is placed across the narrow dimension of the gasket and electrode surface and aligned between microprotrusions. The location of the cord is one of three positions 20 centered, left of center, or right of center. (F) Stacking Electrode/microprotrusion/gasket/cord/gasket units are stacked beginning with a 2 mil (0.00508 cm) end plate unit to the desired number of cells and ending with a plain 2 mil (0.00508 cm) end plate with the cords arranged such that the location is 25 staggered-left, center, right in a three unit repeating cycle (end perspective). (G) Reflow The HDPE gasket is reflowed in nitrogen at 125"C for 120 min to reflow the thermoplastic. The unit is cooled in nitrogen to ambient temperature. (H) Cord Removal 30 The cords are removed by pulling the exposed ends to leave the open fill ports. WO 94/07272 PCT/US93/08803 39 EXAMPLE 3 Alternative Fabrication of Drv Preunit (A) Coating Method The support structure is prepared by etching a 1 mil (0.00254 cm) titanium 5 sheet with 50% Hcl at 75'C for 30 min. The end plates are 10 mil (0.0254 cm) titanium. The oxide coating solution is 0.2 M ruthenium trichloride trihydrate and 0.2 M tantalum pentachloride in isopropanol (reagent grade). The etched Ti sheets are dip-coated by immersion into the solution at ambient 10 conditions. The coated sheet is submerged into the solution, held for about 1 sec and then removed. After each coating, the oxide is dried at 70 *C for 10 min, pyrolyzed at 300*C for 5 min and removed to cool to ambient temperature all in ambient atmosphere. 15 The dip-coating steps are repeated for 10 coats (or any desired number) rotating the Ti sheet so as to dip with alternate sides down. The fully coated sheet is final annealed at 300 *C for 3 hrs in ambient atmosphere. (B) Electrode Pretreatment 20 The coated electrode is contacted with saturated steam in a closed vessel at 260 *C for 2 hrs under autogenic pressure. (C) Spacing Microprotrusions are screen printed on one side of the electrode, as described below, in greater detail, under the heading "SCREEN PRINTING". The epoxy 25 compound is grade EP21AR from Masterbond, Hackensack, NJ. The epoxy protrusions are cured at 150 *C for 4 hr. in air. The coated electrodes are next die-stamped to the desired shape. (D) Gasket A modified high density polyethylene (HDPE, improved puncture resistance 30 and adhesion) 1.5 mil (0.00381 cm) thick by 30 mil (0.0762 cm) wide with outside perimeter the same as that of the electrode is placed on the electrodes on same side WO 94/07272 PCT/US93/08803 40 as the microprotrusions and impulse heat laminated. The HDPE® is grade PJX 2242 from Phillips-Joanna of Ladd, Illinois. IE) £ard One cord (TEFZEL®) 1 mil (0.00254 cm) thick by 10 mil (0.0254 cm) wide is 5 placed across the narrow dimension of the gasket and electrode surface and aligned between microprotrusions. The location of the cord is one of three positions centered, left of center, or right of center. A second HDPE® gasket is placed on the first gasket sandwiching the cord between the two gaskets. 10 The second gasket is impulse heated to adhere to the first gasket and to fi.< the cord in phce. (F) Stacking Electrode/microprotrusion/gasket/cord/gasket units are stacked beginning with a 10 mil (0.0254 cm) end plate unit to the desired number of cells and ending with a 15 plain 10 mil (0.0254 cm) end plate with the cords arranged such that the location is staggered-left, center, right in a three unit repeating cycle (end perspective). (G) Reflow The gasket is reflowed in nitrogen at 160'C for 45 min to reflow the thermoplastic. The unit is cooled in nitrogen to ambient temperature. 20 (H) Cord Removal The cords are removed by carefully pulling the exposed ends to leave the open fill ports. EXAMPLE 4 Alternative Fabrication of Drv Preunit 25 (A) Coating Method The support structure is prepared by etching a 1 mil (0.00254 cm) titanium sheet with 50% HCI at 75 *C for 30 min. The end plates are 5 mil (0.0127 cm) titanium. The oxide coating solution is 0.2 M ruthenium trichloride trihydrate and 0.2 M 30 Ti(di-isopropoxide)bis 2,4-pentanedionate in ethanol (reagent grade). WO 94/07272 PCT/US93/08803 41 The etched Ti sheets are dip-coated by immersion into the solution at ambient conditions. The coated sheet is submerged into the solution, held for about 1 sec and then removed. After each coating, the oxide is dried at 70 ®C for 10 min, pyrolyzed at 5 350*C for 5 min in oxygen and removed to cool to ambient temperature all in ambient atmosphere. The dip-coating steps are repeated for 30 coats (or any desired number) rotating the Ti sheet so as to dip with alternate sides down. The fully coated sheet is final annealed at 350*C for 3 hrs in an oxygen 10 atmosphere. (C) Spacing Microprotrusions are thermally sprayed through a mask on one side of the electrode. The thermal spray material is TEFLON® from E.I. DuPont de Nemours & Co., Wilmington, Delaware. 15 The TEFLON' protrusions are cured at 300*C for 0.5 hr. in air. The coated electrodes are next die-stamped to the desired shape. (D) Gasket A modified high density polyethylene (HDPE, improved puncture resistance and adhesion) 1.5 mil (0.00381 cm) thick by 30 mil (0.0762 cm) wide with outside 20 perimeter the same as that of the electrode is placed on the electrodes on same side as the microprotrusions and impulse heat laminated. The HDPE is grade PJX 2242 from Phillips-Joanna of Ladd, Illinois. (E) Cord One cord (TEFZEL®) 1 mil (0.00254 cm) thick by 10 mil (0.0254 cm) wide is 25 placed across the narrow dimension of the gasket and electrode surface and aligned between microprotrusions. The location of the cord is one of three positions centered, left of center, or right of center. A second HDPE® gasket is placed on the first gasket sandwiching thr ^ord between the two gaskets. 30 The second gasket is impulse heated to adhere to the first gasket and to fix the cord in place. WO 94/07272 PCT/US93/08803 42 (F) Stacking Electrode/microprotrusion/gasket/cord/gasket units are stacked beginning with a 5 mil (0.0127 cm) end plate unjt to the desired number of cells and ending with a plain 5 mil (0.0127 cm) end plate with the cords arranged such that the location is 5 staggered-left, center, right in a three unit repeating cycle (end perspective). (G) Reflow The gasket is reflowed in nitrogen at 190"C for 30 min. to reflow the thermoplastic. The unit is cooled in nitrogen to ambient temperature. (H) Cord Removal 10 The cords are removed by carefully pulling the exposed ends to leave the open fill ports. EXAMPLE 5 Alternative Fabrication of Drv Preunit (A) Coating Method 15 The support structure is prepared by etching a 0.8 mil (0.002032 cm) zirconiun. sheet with 1%HF/20% HN03 at 20 *C for 1 min. The end plates are 2 mil (0.00508 cm) zirconium. The oxide coating solution is 0.2 M ruthenium trichloride trihydrate and 0.1 M tantalum pentachloride in isopropanol (reagent grade). 20 The etched Ti sheets are dip-coated by immersion into the solution at ambient conditions. The coated sheet is submerged into the solution, held for about 1 sec and then removed. After each coating, the oxide is dried at 85 *C for 10 min, pyrolyzed at 310*C for 7 min and removed to cool to ambient temperature all in ambient 25 atmosphere. The dip-coating steps are repeated for 10 coats (or any desired number) rotating the Ti sheet so as to dip with alternate sides down. The fully coated sheet is final annealed at 310* C for 2 hrs in ambient atmosphere. 30 (C) Spacing WO 94/07272 PCT/ US93/08803 43 Microprotrusions are thermally sprayed through a mask on one side of the electrode. The thermal spray material is TEFLON® from E.I. DuPont de Nemours & Co., Wilmington, Delaware. The TEFLON® protrusions are cured at 310"C for 1.0 hr. in air. The coated 5 electrodes are next die-stamped to the desired shape. (D) fiaskfil A polypropylene gasket 1.5 mil (0.00381 cm) thick by 30 mil (0.0762 cm) wide with outside perimeter the same as that of the electrode is placed on the electrodes on same side as the microprotrusions and impulse heat laminated. 10 (E) Cord One cord, 1 mil (0.00254 cm) diameter TEFLON® coated tungsten wire, is placed across the narrow dimension of the gasket and electrode surface and aligned between microprotrusions. The location of the cord is one of three positions centered, left of center, or right of center. 15 A second polypropylene gasket is placed on the first gasket sandwiching the cord between the two gaskets. The second gasket is impulse heated to adhere to the first gasket and to fix the cord in place. (F) Stacking 20 Electrode/microprotrusion/gasket/cord/gasket units are stacked beginning with a 2 mil (0.00508 cm) end plate unit to the desired number of cells and ending with a plain 2 mil (0.00508 cm) end plate with the cords arranged such that the location is staggered-left, center, right in a three unit repeating cycle (end perspective). (G) Reflow 25 The gasket is reflowed in nitrogen at 195*C for 60 min. to reflow the thermoplastic. The unit is cooled in nitrogen to ambient temperature. (H) Cord Removal The cords are removed by pulling the exposed ends to leave the open fill ports. 30 EXAMPLE 6 Filling of the Cell Gap Space WO 94/07272 PCT/US93/08803 44 A dry preunit 10 may be filled with an electrolyte with the following procedure. Any of many possible dry preunit configurations may be used. (H) Back Fill The cords are removed manually to open the fill port. The stacked unit is 5 placed into an evacuation chamber and evacuated to < 35 mtorr for 5 to 60 min. The liquid electrolyte 3.8 M H2S04 de-airated with nitrogen is introduced into the chamber and fills the evacuated space between the electrodes. 10 deionized water to remove excess electrolyte and dried. HDPE film (1.5 mil (0.00381 cm) thick) is placed over the fill port openings and impulse heat sealed over the ports. (J) Conditioning The device is charged up to full charge beginning at 0.1 V/cell increasing by 15 0.1 V/cell until 1 V/cell is obtained. (K) Testing The device is tested in the conventional manner, having 1 V/cell with leakage current of less than 25 //A/cm2, and a capacitance density per a cell of greater than about 0.1 F/cm2. A 10 V device has a height of no more than 0.05", a 40 V device 20 has a height of no more than 0.13", and a 100 V device has a height of no more than 0.27". Performance characteristics for various device geometries and configurations based on a sulfuric acid electrolyte are presented in Table 1. Table 1 25 Ultracapacitor Device Performance Characteristics (I) Seal Fill Port Openings The electrolyte filled preunit is removed from the chamber. It is rinsed with Area/cm2 2 2 2 2 25 25 10 40 100 100 100 100 26 6.7 2.6 10 150 753 100 330 780 780 62 70 0.29 0.73 1.6 1.6 11 32 volt C/mF ESR/mohm 30 vol/cc J/cc 4.5 7.4 8.1 31 69 111A WO 94/07272 PCT/US93/08803 45 watt/cc 860 1660 2000 2000 3670 1100 EXAMPLE 7 Alternative Backfill of Drv Preunit A dry preunit 10 may be filled with an electrolyte with the following 5 procedure. Any of many possible dry preunit configurations may be used. <H) Back Fill The cords are removed to open the fill port. The stacked unit is placed into an evacuation chamber and evacuated to < 35 mtorr for 5 to 60 min. The liquid non-aqueous electrolyte 0.5 M KPFe in propylene carbonate de-airated with nitrogen 10 is introduced into the chamber and fills the evacuated space between the electrodes. (I) Seal Fill Port Openings The electrolyte filled preunit is removed from the chamber and excess electrolyte is removed. HDPE film (1.5 mil (0.C0381 cm) thick) is placed over the fill port openings and impulse heat sealed over the ports. 15 (J) Conditioning The device is charged up to full charge beginning at 0.1 V/cell increasing by 0.1 V/cell until 1.5 V/cell is obtained. (K) Testing The device is tested in the conventional manner, having 1.5 V/cell with 20 leakage current of around 100//A/cm2, and a capacitance density of around 4 Mf/cm2 for a 10 cell device. EXAMPLE 8 DEVICE POST-TREATMENT CONDITIONS The following is a list of the electrical properties (Table 3) of devices using 25 various gas postconditioning techniques to adjust the electrode rest potential so that charging to at least 1 V/cell on multicell devices filled with 4.6 M sulfuric acid electrolyte is possible and reduced leakage currents are observed. This treatment is done before, during, and/or after reflow of the gasket material. For gas treatment at temperatures below that used for gasket reflow the atmosphere was exchanged with 30 an inert gas such as nitrogen or argon during reflow. For treatment after reflow of WO 94/07272 PCT/US93/08803 46 the gasket material the tabs were removed before treatment. During treatment the atmosphere is evacuated and filled with the reactive gas periodically. TAPL5 3 Device characteristics for various postconditioning. aas T/'C t/min. V'luMcm2 V/cell h2 50 20 8 1.0 CO 100 170 40 1.0 CO 90 103 12 1.0 CO 90 165 20 1.0 CO 80 120 25 1.1 no 75 20 27 1.0 no 95 140 21 1.1 nh3 85 30 26 1.0 FORMATION OF MICROPROTRUSIONS BY SCREEN PRINTING 15 EXAMPLE 9 Application of Epoxv Microprotrusions bv Screen Printing onto a Porous Coatino on a Thin Substrate (A) Screen Preparation - A 325 mesh stainless steel screen is stretched on a standard screen printing frame. To this screen is edge glued (Dexter Epoxy 608 clear) 20 to a smaller 1-1.5 mil (0.00254 to 0.00381 cm) thick brass sheet which has holes (6.3 mil (0.016 cm) diameter) drilled or etched to the desired pattern. The screen mesh is removed from the area covered by the brass sheet leaving the brass sheet edge glued to the screen mesh attached to the frame. (B) Sample Holding - A vacuum is pulled on a porous alumina holding plate of 10 25 frm average pore diameter is used to hold the 1 mil (0.00254 cm) thick porous oxide coated material during the printing. (C) Epoxy - A two component epoxy Master Bond EP21 AR is modified to the desired viscosity (thixotropic, 300,000 to 400,000 cps) by the addition of a silica filler. The filled epoxy having the desired viscosity is available by purchase order from Master 30 Bond, Inc. of Hackensack, New Jersey. The epoxy is prepared as per instructions. The useful lifetime as a flowable fluid is about 30 min. WO 94/07272 PCI7US93/08803 47 (D) Screen printer parameters --squeegee speed: 1-2 in/s snap off: 20-30 mil {0.0508 to 0.0782 cm) Constant temperature and humidity of the epoxy are important to assure an 5 even applied coat. Typical conditions are about 40-70% relative humidity and a temperature of about 20-25°C. (E) Printed epoxy pattern -- An array of epoxy bumps essentially 1 mil (0.00254 cm) in height and about 7.5 mil (0.019 cm) in diameter are produced. A typical pattern on an electrode consists of an array of microprotrusions deposited on 40 mil (0.1016 10 cm) center-to-center spacing. In addition, the density of microprotrusions at the perimeter of the electrode is increased by decreasing their center-to-center spacing to 20 mil (0.508 cm). The screen printed epoxy configuration is cured at 150°C for a minimum of 4 hr. EXAMPLE 10 15 Screen Print Formation of Eooxv Microprotrusions (A) Screen Preparation -- A 230 or 325 mesh screen (8x10 in stainless steel) without an emulsion on the surface, mounted on a standard printing frame, is used as the base piece. An etched, drilled or punched stencil (6.0 x 8.5 molybdenum) is edge glued using Dexter Epoxy 608 Clear from Dexter located to the back side of the screen. 20 MYLAR® is placed over the stencil-screen unit and pressure applied to smooth the epoxy into a uniform layer. The screen is then flipped, epoxy applied to the top side of the screen, a MYLAR® sheet placed over the area and the epoxy smoothed. The MYLAR® sheet on the top side of the screen is then removed. The screen-stencil assembly is then placed 25 into a 120°C oven with ambient atmosphere for 5 min to cure the epoxy. Alternatively, the epoxy can be cured by setting at ambient temperature for 30-60 min. After removal of the screen-stencil from the oven, the MYLAR® on the back side is carefully peeled away immediately. The mesh screen on the top side is then cut away using a sharp edge, with care being taken to prevent cutting of the stencil. Upon 30 removal of the mesh over the stencil pattern, any heat stable thermoset adhesive (e.g. an epoxy resin) is applied to the cut mesh-stencil perimeter, covered with MYLAR®, and WO 94/07272 PCT/US93/08803 48 the epoxy smoothed to ensure edge attachment of the screen to the stencil. The epoxy is cured in the oven for 5 min. The resulting item is a stencil stretched taut by the screen, ready for printing. (B) Sample Holding - A porous ceramic holding (e.g. Fig. 8) plate (Ceramicon 5 Designs, Golden, Colorado, P-6-C material) of 4.5-6// pore diameter with a porosity of 36.5% (30-60% porosity is acceptable) is used to hold the 1 mil (0.00254 cm) thick porous oxide coated material during the printing by pulling a vacuum through the porous ceramic plate. The ceramic plate is cut to the appropriate dimensions (the size and shape of the substrate to be printed). This csramic plate then is inserted into an 10 aluminum (steel, etc) frame 277 and epoxy or other adhesive) that can be mounted to a screen printer. The ceramic plate is then carefully ground flush to the metal frame as flat as possible. Locating pins 278, 279 and 280 are then added to hold the substrate 11 IA in appropriate location using holes 281, 282 and 283. (C) Epoxy - The Master Bond EP 21 ART® (a two component epoxy (of 15 polyamine hardener, 33 weight percent and a liquid epoxy resin, 67 weight percent) about with a viscosity of 150,000 to 600,000 cps). The epoxy is prepared as per the product instructions. The useful lifetime as a flowable fluid is about 30 min. (D) Screen Printing Parameters -Squeegee Speed 1-2 in/s (depends 20 upon epoxy viscosity) Snap Off 20-30 mil (0.0050 to 0.0076 cm) (Related to screen tension; and adjusted accordingly) (E) Printed epoxy pattern - An array of epoxy bumps essentially about 1 to 25 1.25 mil (0.0C\?54 to 0.00316 cm) in height and about 7.5 mil (0.019 cm) in diameter are produced. A typical pattern on an electrode consists of an array of microprotrusions deposited on 40 mil (0.1 cm) center-to-center spacing. In addition, the density of microprotrusions around the perimeter of the electrode is increased by decreasing their center-to-center spacing to 20 mil (0.0508 cm). The screen printed epoxy configuration 30 is cured at 150°C for 4 to 12 hrs. in an ambient atmosphere. WO 94/07272 PCT/US93/08803 49 EXAMPLE 11 ALTERNATIVE SCREEN PRINTING PARAMETERS (A) Separator Bumps - Separator bumps range in height from .001 to .004 in. (.00254 to 0.01016 cm) and widths of .006 to .012 in. (.01524 to .03038 cm). 5 Separator bumps may take the form of dots, squares, rectangles or a composite of these shapes. The widths of the bumps increase as the bump height is increased. (B) Separator Pattern - Two patterns are utilized on an electrode substrate, the Active Field Area and the Bounding Border Area. The AFA has the separator bumps located on .040 by .040 in. (.1016 by .1016 cm) center to center spacing and are 10 normally dots. The BBA has an increased bump density with a .020 by .020 in. (.0508 by .0508 cm) center to center spacing. Rows of rectangles alternate between arrays of dots. (C) Screen Preparation - Design of the separator configuration is performed on a CAD (Computer Aided Drafting) system. The CAD electronic data is converted to a 15 Gerber plot file. This plot data is used by the screen manufacture to create the artwork to produce the desired thickness stencil for the screen printer. The screen is sent ready to use by SMT (Screen Manufacturing Technologies of Santa Clara, California). (D) Electrode Vacuum Plate (Workholder) - A porous ceramic plate (Ceramicon Designs, Golden, Colorado, P-6-C material) trimmed .050 smaller than the electrode 20 perimeter is fitted and epoxied into an aluminum plate designed to fit the screen printer. The top and bottom surfaces are ground flush and parallel. Multiple pins are inserted around the centered electrode edge creating a corner stop for placement of the electrode substrate. (E) Epoxy — A two component epoxy Master Bond EP21 AR is modified to the 25 desired viscosity (thixotropic, 300,000 to 400,000 cps) by the addition of a silica filler. The filled epoxy having the desired viscosity is available by purchase order from Master Bond, Inc. of Hackensack, New Jersey. The epoxy is prepared as per instructions. The useful lifetime as a flowable fluid is about 30 min. (F) Screen Printing Parameters 30 Thick Film Screen Printer Squeegee Durometer 45 to 100 Type A WO 94/07272 PCT/US93/08803 50 Squeegee Speed 1 -2 in/s Squeegee Pressure 10 to 15 lbs. Squeegee Down Stop .010 to max. in. Snap Off .010 to .030 in. (.0254 to .0762 cm.) 5 FORMATION OF MICROPROTRUSIONS BY PHOTOLITHOGRAPHY EXAMPLE 12 Hot Roller Photolithographic Production of Microprotrusions (A) The ConforMASK® 2000 high conformance solder mask of 1.5 mil (0.0038 cm) in thickness is cut to the same size as the electrode. 10 (B) The photo resist film 381 is applied by placing the ConforMASK® film on the electrode material surface 111A, after removing a release sheet 382 between the phoio resist film 381 and the electrode 111 A, and passing the laminate through heated rollers (384 and 385), at 150°F, to adhere the photoresist film 381 to the electrode surface 111 A. A polyester cover sheet 382A on the outside of the photo resist film 15 381 is then removed. (C) A dark field mask 387 containing rows of transparent holes (openings 388) is placed on the photo resist 381. A typical pattern consists of an array of holes 6 mil (0.0212 cm) in diameter 40 mil (0.1 cm) center-to-center spacing with a higher density (20 mil (0.0508 cm) center-to-center) for three rows on the perimeter of the 20 electrode. (D) The film 381 is exposed through the holes 388 and the mask 387, for about 20 seconds, to a conventional UV light source, i.e. mercury vapor lamps 389. The mask is then removed. (E) The unexposed area of the photo resist is developed or stripped by placing 25 it in a tank with 1 % potassium carbonate for 1.5 min. (F) The electrode surface with the microprotrusions (standoffs) are then washed with de-ionized water, placed in a tank with 10% sulfuric acid, for 1.5 min and a final de-ionized water rinse. (G) First, the microprotrusions 13 are exposed to UV light. A final cure of the 30 microprotrusions (standoffs) is done in a convection air oven at 300°F for 1 hr. The finished electrode 111A is used directly, or is treated, as described above. WO 94/07272 PCT/US93/08803 51 EXAMPLE 13 Vacuum Lamination of Photo resist (A) The ConforMASK® 2000 high conformance solder mask of 2.3 mil (0.0058 cm) in thickness is cut slightly larger than the electrode. 5 (B) The photo resist film is 381 vacuum laminatsd to the electrode 111 A, and onto a supporting backing plate using standard operating conditions (160°C, 0.3 mbars) using a Dynachem vacuum applicator model 724 or 730. The polyester cover sheet 382A is removed. (C) The dark field mask 387 containing rows of transparent holes 388 is 10 placed on the photo resist film 381. A typical pattern includes an array of holes 6 mil (0.0015 cm) in diameter 40 mil (0.102 cm) center-to-center spacing with a higher density (20 mil (0.0054 cm) center-to-center) for three rows on the perimeter of the electrode. (D) The film is exposed for 20 to 40 seconds to a non-collimatad UV light 15 source of 3-7 KW power. (E) The unexposed area of the photo resist film is developed or stripped by using 0.5% potassium carbonate in a conveyorized spray developing unit, followed by a de-ionized water rinsing and turbine drying. (F) A final cure of the microprotrusion standoffs is done in a two step 20 process. First, the microprotrusions are exposed to UV light in a Dynachem UVCS 933 unit and then placed in a forced air oven at 300-310°F for 75 min. The finished electrode is used directly or further treated as described above. EXAMPLE 14 25 Surfactants for Porosity Control 32g of cetyltrimethyl ammonium bromide was added to 11 of iso-propanol with stirring and slight heat. After approximately one hour 73 g of TaCI5 and 47 g of RuCI3*H20 was added to the clear solution. The standard coating procedure was performed with interim pyrolysis at 300°C or 5 min. and a final pyrolysis at 300°C 30 tor ?< hours. The average pore diameter of the coating increased to around 45 A. After WO 94/07272 PCT/US93/08803 52 post-treatment in steam at 260°C at 680 psi for 2 hr. the average pore diameter increased to 120 A. A 25 wt % cetyitrimethyl ammonium chloride in water solution may also be used to modify the pore diameter of the resulting coating. 5 EXAMPLE 15 Thermal Elastomeric Gasket An alternative construction methodology is to sandwich a thermal elastomer gasket (e.g. KRATON®) between the two HDPE gaskets. Device characteristics are 10 similar to those previously described. EXAMPLE 16 Inclusion of Second Material to Accommodate Electrolyte Volume Increases A porous hydrophobic material is added to each cell to accommodate any volume increase of the electrolyte due to an increase in temperature. 15 This material is placed in the cell as either a gasket material inside the perimeter HDPE gasket, or as a disk replacing part of the separator material. A common material used is a PTFE material from W.L. Gore & Associates, Inc. 1-3 mil thick. Preferably, the PTFE material has water entry pressures from 20 to 100 psi. 20 EXAMPLE 17 Alternate Electrode Pretreatment After the electrodes have microprotrusions, gaskets, and pull cards (after step E), the electrodes are placed in 1M sulfuric acid and the open circuit potential is adjusted to about 0.5V (vs HHE) using cathodic current with no hydrogen evolution. 25 The electrodes are transferred submerged in deionized water to an inert atmosphere (e.g. Ar) where they are dried and assembled. While only a few embodiments of the invention have been shown and described herein, it will become apparent to those skilled in the art that various modifications and changes can be made in the improved method to produce an electrical storage device 30 such as a battery or a capacitor having improved lifetime and charge/recharge characteristics and low leakage current, and the device thereof without departing from WO 94/07272 PCT/US93/08803 53 the spirit and scope of the present invention. Ail such modifications and changes coming within the scope of the appended claims are intended to be carried out thereby. </div>

Claims

1. WO 94/07272 PCT/US93/08803 54 WE CLAIM:

1. A dry preunit for an energy storage device comprising: at least a first cell for storing energy, said first cell comprising, in combination: a. a first electrically conductive electrode; 5 b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first predetermined distance; and c. first dielectric gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes; 10 whereby, when said first electrode, said second electrode and said first gasket means having a centrally located opening are bonded together to form said first cell, an air filled fill gap is formed therebetween.

2. The dry preunit according to claim 1, wherein said first cell further includes: a. a first high surface area electrically conducting coating layer formed on one surface of said first electrode, such that said first coating layer is 5 interposed between said first electrode and said gasket means; and b. a second electrically conducting high surface area coating layer formed on one surface of said second electrode, such that said second coating layer is interposed between said second electrode and said first gasket means; 10 c. a layer which includes a plurality of protrusions on the first coating layer, the second coating layer, or combination thereof; and wherein said protrusions impart structural support to said first cell, and provide additional insulation between said first and second electrodes.

3. The dry preunit according to claim 2, wherein said first cell further includes a first fill port formed by said gasket means, in order to allow an electrolyte to flow into said fill gap. PCT/US93/08803 25 6 3 2 9 55

4. The dry preunit according to claim 3, wherein said first cell further includes a first cord which is inserted within said first fill port; and wherein when said first cord is removed, said first fill port is opened and said fill gap becomes accessible.

5. The dry preunit according to claim 1 or 4, further including at least a second cell, and wherein said first cell and said second cell are stacked and connected, in order to impart an integral unitary structure to the dry preunit.

6. The dry preunit according to claim 5, wherein said second electrically conductive electrode is a bipolar electrode, which is shared by said first and second cell; and wherein said second cell further includes a third electrically conductive electrode 5 which is oppositely disposed relative to said second electrically conductive electrode; and wherein said second and third electrically conductive electrodes are spaced apart, by a second predetermined distance.

7. The dry preunit according to claim 6 including a third high surface area electrically conducting coating layer and a second gasket means wherein said third coating layer is formed on the second flat surface of said second electrode, such that said second coating layer is interposed between said second electrode and said second gasket means; and wherein said second cell includes a plurality of discrete protrusions located on either electrode surface.

8. The dry preunit according to claim 7, wherein said second cell includes a fourth high surface area electrically conductive coating layer which is formed on one surface of said third electrode; and wherein said fourth coating layer is interposed between said third electrode and said second gasket means. N.Z. PATENT OFFICE 27 NOV 1996 | ~ RECEIVS ] WO 94/07272 WO 94/07272 PCT/US93/08803 256 32 9 56

9. The dry preunit according to claim 8, wherein said second cell further includes a second fill port that is formed within said second gasket means.

10. The dry preunit according to claim 9, further including exterior tab means for connection to a power source.

11. The dry preunit according to claim 8, wherein each of said first and third coating layers includes an additional layer having a set of peripheral protrusions, and a set of central discrete protrusions that are disposed in an arrayed arrangement.

12. The dry preunit according to claim 11, wherein the diameter of each protrusion is about 6 mil (0.015 cm); wherein the center-to-center separation of said peripheral protrusions is about 20 mil (0.0508 cm); 5 wherein the center-to-center separation of said central protrusions is about 40 mil (0.102 cm); and wherein said peripheral and central protrusions have a dielectric composition.

13. The dry preunit according to claim 6, wherein said first and second predetermined distances are equal.

14. The dry preunit according to any one of claims 7-12, wherein each of said first and second gasket means includes two dielectric gaskets, which are disposed in registration with each other; and wherein said first cord is disposed between said gaskets to form said first fill 5 port.

15. The dry preunit according to claim 6, wherein said first, second and third electrodes are similarly and rectangularly shaped.

16. A capacitor preunit including at least a first cell, the capacitor comprising; N.Z. PATENT Office 87 NOV 1936 REC33VE0 i WO 94/07272 PCT/US93/08803 256 32 9 57 a. a first electrically conductive electrode; b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first predetermined distance; and 5 c. first dielectric peripheral gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means are bonded together to form the first ceil, a fill gap is formed therebetween.

17. The capacitor preunit according to claim 16, wherein the first cell further includes: a. a first high surface area coating layer formed on one surface of said first electrode, such that said first coating layer is interposed between said 5 first electrode and said gasket means; and b. a second high surface area coating layer formed on one surface of said second electrode, with the proviso that said second coating layer is interposed between said second electrode and said first gasket means; c. a layer having a plurality of discrete protrusions; and 10 wherein said protrusions impart structural support to the first cell, and provide additional insulation between said first and second electrodes.

18. The capacitor preunit according to claim 17, further including at least a second cell; wherein the first and second cell are stacked and bonded, in order to impart an integral unitary structure to the capacitor; 5 wherein said second electrically conductive electrode is a bipolar electrode, which is shared by said first and second cell; wherein said second cell further includes a third electrically conductive electrode which is oppositely disposed relative to said second electrically conductive electrode; and j &7 MOV 1596 58 25 6 32 9 wherein said second and third electrically conductive electrodes are spaced apart, by a second predetermined distance.

19. A method for storing energy using the dry preunit according to any one of [ j claims 1 through 15, wherein said preunit is charged with an ionically conducting w electrolyte, sealed, and electrically charged.

20. a method for making a dry preunit comprising the steps of forming at least a first cell by: a. spacing apart a first electrically conductive electrode and a second electrically conductive electrode, by a first predetermined distance; and b. placing a first dielectric gasket means between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode and said first gasket means are bonded together to form said first cell, a fill gap is formed therebetween.

21. A method for making a capacitor preunit comprising the steps of forming at least a first cell by: a. spacing apart a first electrically conductive electrode and a second electrically conductive electrode, by a first predetermined distance; and 2 7 NOV O 94/07272 PCT/US93/08803 25 6 3 2 5 59 b. placing a first dielectric gasket means between said first and second electrodes, for separating and electrically insulating said first and second electrodes; whereby, when said first electrode, said second electrode end said first gasket means are bonded together to form said first cell, a fill gap is formed therebetween.

22. The method for making an dry preunit according to claim .21, further including the steps of: a. forming a first porous, high surface area, and conductive coating layer on one surface of said first electrode, such that said first coating layer is interposed between said first electrode and said gasket means; b. forming a second porous, high surface area, and conductive coating layer on one surface of said second electrode, such that said second coating layer is interposed between said second electrode and said first gasket means; and c. forming a plurality of discrete microprotrusions on said first coating layer, wherein said microprotrusions impart structural support to said first cell,

-23- An improved method to produce a dry preunit of an electrical storage device for storage of electrical charge in a condition to have the electrode surfaces contacted with a non-aqueous or aqueous electrolyte, which method comprises: WO 94/07272 60 PCT/US93/08803 25 6 32 9 (a) preparing a thin in thickness substantially flat sheet of electrically 5 conducting support material coated on each flat side with the same or different thin layer of a second electrically conducting material having a high surface area, optionally with the provision that both fiat sides of the electrically conducting support is a sheet having the perimeter edge surfaces either: ^(i) having a thin layer of second electrically conducting 10 material, or (ii) are partly devoid of second electrically conducting material, or (iii) are devoid of second electrically conducting material; (b) creating an ion permeable or semipermeable space separator stable 15 to the aqueous or non-aqueous electrolyte obtained by: (i) depositing substantially uniform in height groups of electrically insulating microprotrusions, on the surface of at least one side of the thin layer of second electrically conducting material, (ii) placing a thin precut ion permeable or semipermeable 20 separator on one surface of the second electrically conducting material, or (iii) casting an ion permeable or semipermeable thin layer on the surface of at least one side of the electrically conducting material, or (iv) creating a thin air space as separator; 25 (c) contacting the perimeter edge surface of one or both sides of the thin sheet of step (b) with one or more thin layers of synthetic organic polymer as a gasket material selected from the group consisting of a thermoplastic, thermoelastomer, and a thermoset polymer; (d) placing on or within the gasket material and optionally across the 30 thin sheet at least one thin cord of a different material which cord has a higher melting point (Tm) greater than the gasket polymer material and does not melt, flow, or permanently adhere to the gasket under the processing conditions; N.z. : 24 FEB ©7 -•-ICE WO 94/07272 PCT/L'S93/08803 61 25 6 32 9 (e) producing a repeating layered stack of the thin flat articles of sheet coated with high surface area coating and separator produced in step (d) 35 optionally having the end sheets consisting of a thicker support; (f) heating the stack produced in step (e) at a temperature and applied pressure effective to cause the synthetic gasket material to flow, to adhere to, and to seal the edges of the stack creating a solid integral stack of layers of alternating electrically conductive sheet coated with second electrically 40 conducting material and the ion permeable separator, optionally such that the gasket material creates a continuous integral polymer enclosure; (g) cooling the solid integral stack of step (f) optionally in an inert gas under slight pressure; and (h) removing the at least one thin cord of different material between 45 each layer creating at least one small opening between the layers of electrically conducting sheet coated with second electrically conducting material.

24. The method of claims 22 or 23, wherein said microprotrusions comprise ceramics, organic elastomers, thermoplastics, or thermosets, or combinations thereof.

25 • The method of claim 24, wherein either after step (e) and before step (f) or after step (h), the integral stack is treated by: (j) evacuating the dry preunit to substantially remove residual gases; (k) contacting the dry unit with one or more reducing gases at near 5 ambient pressure; (I) heating the unit and reducing gas to between about 20 to 150° C for between about 0.1 and 5 iir; (m) evacuating the dry preunit; (n) replacing the reducing atmosphere with inert gas; and 10 (o) optionally repeating steps (j), (k), (I), (m), and (n) at leest once.

26. The method of claim 23, wherein either after step (e) and before step (f) or after step (h), the integral stack is treated by: (j) evacuating the dry preunit to substantially recnove-iiesidual gases; WO 94/07272 PCT/US93/08803 25 6 3 2 9 62 (k) contacting the dry unit with one or more reducing gases at near 5 ambient pressure; (I) heating the unit and reducing gas to between about 20 to 150°C 10 for between about 0.1 and 5 hr; (m) evacuating the dry preunit; (n) replacing the reducing atmosphere with inert gas; and (o) optionally repeating steps (j), (k), (I), (m), and (n) at least once.

27. The method according to claim 25 or 26, wherein the vacuum in steps (j), (m) and (o) is between about 1 torr to 1//torr.

28. The method according to claim 26 or 27, wherein the reducing gas is selected from hydrogen, carbon monoxide, nitric oxide, ammonia or combinations thereof; and the inert gas is selected from helium, neon, nitrogen, argon or combinations 5 thereof; and the one or more reducing gases and one or more inert gases are contacted with the unit in a sequential manner.

29. The method according to claim 23, wherein: in step (b) gasket material is placed on the top of the device and the gasket material between the electrodes is of sufficient excess in volume so that upon heating in step (f) excess gasket material extrudes about the perimeter edges of the support to 5 create a seamless sealed integral surface at tha edge of the stack unit.

30. The method according to clairn 23, wherein in step (a) the support has second electrically conducting material on the perimeter edge surfaces, in step (b) the microprotrusions are on the surface of the second electrically 5 conducting material, in step (c) the gasket material is a thermoplastic, rO 94/07272 PCT/L'S93/08803 25 6 32 9 63 in step (e) the end sheets are a thicker support material, in step If) the gasket material is in excess to create a continuous integral sealed enclosure, 10 in step (g) the stack is cooled to ambient temperature, and in step (h) the cord comprises 8 metal, ceramic, organic polymer or combinations thereof.

31. A method of forming an electrical storage device for storage of electrical charge, which method comprises: providing a dry preunit produced accordingly to any one of claims 23 to 30, evacuating the dry preunit, contacting the evacuated dry preunit with an electrolyte selected from either an 5 aqueous inorganic acid or a non-aqueous organic ionically conducting medium for a time sufficient to backfill the space between the support sheets using the fill port, removing any exterior surface electrolyte, and closing and sealing the fill port openings.

32. An improved method to produce a dry preunit of an electrical storage device for storage of electrical charge in a condition to have the electrode surfaces contacted with a non-aqueous or aqueous electrolyte, which method comprises: (a) obtaining a thin in thickness flat metal sheet support wherein the metal 5 is selected from titanium, zirconium, iron, copper, lead, tin, nickel, zinc or combinations thereof, having a thickness of between about 0.1 and 10 mil coated on each flat surface with a thin porous layer of at least one metal oxide having a high surface area independently selected from metal oxides of the group consisting of tin, lead, vanadium, titanium, ruthenium, tantalum, rhodium, osmium, iridium, iron, cobalt, nickel, copper, 10 molybdenum, niobium, chromium, manganese, lanthanum or lanthanum series metals or alloys or combinations thereof, possibly containing small percentage of additives to enhance electrical conductivity, wherein the thin metal oxide layer has a thickness of between about 0.1 and 100 microns, 15 optionally with the provision that both flat surfaces of the electrically conducting sheet have the perimeter edge surfaces devoid of metal oxide; ►'O 94/07272 PCT/US93/08803 256329 64 (b) creating an ion permeable space separator which is stable to the aqueous or non-aqueous electrolyte selected by. (I) depositing a substantially uniform in height array of electrically insulating discrete microprotrusions which are stable to an aqueous or nonaqueous electrolyte having a height of between about 0.1 and 10 mil on the surface of one or both sides of the thin layer of porous metal oxide, or (ii) placing a thin precut ion permeable electrically insulating separator having a thickness of between about 0.1 and 1.0 mil on one flat surface of the metal oxide layer; or (iii) casting an ion permeable or semipermeable separator having a thickness of between about 0.1 and 10 mil on at least one surface of the metal oxide layer; or (iv) creating a thin air space as a separator; (c) contacting the perimeter edge surface of one or both sides of the thin electrically conducting sheet of step (b) with one or more thin layers of synthetic organic polymer as a gasket material wherein the potymer is selected from a group containing polyimides, — TEFZEL®, KRATON®, polyethylenes, polypropylenes, other polyolefins, polysulfone, other fluorinated or partly fluorinated polymers or combinations thereof; (d) placing on or within the gasket material and optionally across the thin flat sheet at least one thin cord of a different material which has a higher melting temperature (Tmi than the polymeric gasket material, which cord does not melt, flow or adhere to the gasket material under the processing conditions described herein; (e) assembling a repeating layered stack of the thin flat articles of sheet coated with metal oxide and separator produced in step (d) optionally having end sheets having only one side coated and/or being made of thicker support material; (f) heating the layered stack of step (e) at 0 to 100° C greater than Tm of the gasket material causing the gasket material to flow, to adhere to, and to seal the edges of the layered stack creating a solid integral layered stack of sheet and separator optionally enclosing and sealing the stack in an integral polymer enclosure; (g) cooling to ambient temperature the solid integral stack of^step (f) in an inert environment; and N.7. r\ATFNT OFFICE] 24 FEB 1S97 94/07272 PCT/US93/08803 25 6 32 9 65 (h) removing the at least one thin cord between each layer creating at least one small opening into the fiil gap located between the porous electrode layers.

33. The method according to claim 32, wherein: in step (b) gasket material is placed on tho top of the device and the gasket mateiial between electrodes is of sufficient excess in volume so that upon heating in step (f) excess gasket material extrudes r.oout the perimeter edges of the support to create a seamless sealed integral surface at the edge of the stack unit.

34. The method according to claim 32, wherein: in step (a) the support has second electrically conducting material on the perimeter edge surfaces, in step (b) the microprotrusions are on the surface of the second electrically conducting material, in step (c) the gasket material is a thermoplastic, in step (e) the end sheets are a thicker support material, in step (f) the gasket material is in excess to create a continuous integral enclosure, in step (g) the stack is cooled to ambient temperature, in step (h) the cord comprises a metal, ceramic, organic polymer or combinations thereof.

35. An energy storage device including a preunit device produced according to the method of any one of claims 23 or 29 and adding an electrolyte to fill the evacuated fill gap regions. sealing the fill port openings, and electrically charging the electrical storege device wherein said device has uses as an electrical source of power for applications independently selected from: providing peak power in applications of varying power demands and be recharged during low demand (i.e. serving as means for a power conditioner, placed between the electrical generator and the electrical grid of the O'rr^OS \ 24 FEB A997 V" O 94/07272 PCT/US93/08803 25 6 32 9 66 10 providing power in applications where the electrical source may be discontinued and additional power is needed to power in the interim period or for a period to allow for a shutdown providing means for uninterruptable power source applications, comprising computer memory shutdown during electrical grey and brown outs, or power during periodic black outs as in orbiting satellites; 15 providing pulse power in applications requiring high current and/or energy comprising means for a power source to resistively heat catalysts, to power a defibrillator or other cardiac rhythm control device, or to provide pulse power in electric vehicle where in a battery or internal combustion engine could recharge the device; providing power in applications that require rapid recharge with prolonged energy 20 release comprising surgical instruments with out an electrical cord; or providing a portable power supply for appliance and communication applications.

36. The dry preunit according to claim 1 or 5, wherein said first electrode includes a first electrically conductive, high surface area, porous coating layer, which is formed on one surface thereof, such that said first coating layer is interposed between said first electrode and said gasket means; and 5 wherein said second electrode is a bipolar electrode.

37. The dry preunit according to claim 36, wherein said second electrode includes a first electrically conductive, high surface area, porous coating layer formed on one surface thereof, such that said second coating layer is interposed between said second electrode and said first gasket means.

38* The dry preunit according to claim 37, wherein said first electrode further includes spacer means formed on said first coating layer, for maintaining said first and second electrodes closely spaced apart.

39. The dry preunit according to claim 38, wherein said second electrode further includes a second electrically conductive, high surface area, porous coating layer formed on another surface thereof. 67. '25 6 3 2 P

40. The dry preunit according to claim 38, wherein said first coating layer of said first electrode, and said first and second coating layers of said second electrode are selected from a group consisting of metal oxides, mixed metal oxides, metal nitrides, and polymers.

41. The dry preunit according to claim 38, wherein said spacer means includes a plurality of protrusions; and wherein said protrusions impart structural support to said first cell, and provide additional insulation between said first and second electrodes.

42. The dry preunit or capacitor preunit or electrical storage device claimed in or produced by the method claimed in any one of claims 1 to 18, and 20 to 41 further including an ionically conductive medium, within the cell gaps of the dry preunit, wherein the fill ports are sealed.

43. The dry preunit according to any one of claims 1 to 15 or as produced by the method of any one of claims 20, 22, and 32 including porous hydrophobic polymeric material within the fill gap of each cell to mitigate the increase of hydrostatic pressure with an increase in temperature.

44. The dry preunit of claim 43 wherein the porous hydrophobic polymeric material comprises polytetrafluoroethylene and has water entrance pressures of between 760 and 7600 torr.

45. The method of claim 32 wherein in step (a) the metal oxide coated metal sheet formed in that step is conditioned by contact with: (a) steam at a temperature of between about 150 and 300°C for between about 0.5 and 4 hr, or m •68- 25 6 32 9 (b) a reactive gas or a reactive liquid at a temperature of between about 80 to 140°C for between about 0.2 and 2 hr, or (c) an anodic current sufficient to evolve oxygen for between about 1 to 60 min, then contacted with a cathodic current without hydrogen gas evolution until the open circuit potential is adjusted to between about 0.5V to 0.75V (vs. normal hydrogen electrode).

46. The method of claim 32 wherein between steps (d) and (e) the porous coating is conditioned by contact with a cathodic current until the open circuit potential is adjusted to between about 0.5V to 0.75V (vs. normal hydrogen electrode).

47. An energy storage device including a dry preunit according to any one of claims 1 to 15.

48. An energy storage device including a capacitor preunit according to any one of claims 16-18.

49. A dry preunit substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings.

50. A capacitor preunit substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings.

51. A method of manufacturing a dry preunit as claimed in claim 20 or claim 32 substantially a? herein described.

52. a method for manufacturing a capacitor preunit as claimed in claim 21 substantially as herein described. 2,4 FB ^$7 \ END OF CLAIMS \ < u———~j