US 5,711,988 A · Energy storage device and its methods of manufacture

Abstract

A dry preunit (10), includes a plurality of cells (110, 112, 114) in a true bipolar configuration, which are stacked and bonded together, to impart to the device an integral and unitary construction. Each cell (114) includes two electrically conductive electrodes (111A, 111B) that are spaced apart by a predetermined distance. The cell (114) also includes two identical dielectric gaskets (121,123) that are interposed, in registration with each other, between the electrodes (111A, 111B), for separating and electrically insulating these electrodes. When the electrodes (111A, 111B), and the gaskets (121, 123) are bonded together, at least one fill gap (130) is formed for each cell. Each cell (114) also includes a porous and conductive coating layer (119, 120) that is formed on one surface of each electrode. The coating layer (119) includes a set of closely spaced-apart peripheral microprotrusions (125), and a set of distally spaced-apart central microprotrusions (127). These microprotrusions (125, 127) impart structural support to the cells, and provide additional insulation between the electrodes. An energy storage device (10A) such as a capacitor, is created with the addition of an electrolyte to the gap (130) of the dry preunit (10) and subsequent sealing of the fill ports.

Claims17

Dependent claims

A method of producing an array of substantially uniform microprotrusions on a 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 electrolyte conditions to produce a thixotropic composition at between ambient temperature to about 75.degree. 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 flat 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 sample from the screen printer;
and
(f) curing the applied material whereby the discrete microprotrusions essentially retain their shape and dimensions.

4 more elements

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) preparing a thin in thickness substantially flat sheet of electrically 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 flat sides of the electrically conducting support is a sheet having the perimeter edge surfaces either:
(i) having a thin layer of second electrically conducting material,
(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 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 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;
(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 thin sheet at least one thin cord of a different material which cord has a higher melting point (T.sub.m) greater than the gasket polymer material and does not melt, flow, or permanently adhere to the gasket under the processing conditions;
(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) 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 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 each layer creating at least one small opening between the layers of electrically conducting sheet coated with second electrically conducting material.

13 more elements

An improved method to produce a dry preunit or 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 is selected from titanium, tantalum, niobium, 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, 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 200 microns,
optionally with the provision that both flat surfaces of the electrically conducting sheet have the perimeter edge surfaces devoid of metal oxide;
(b) creating an ion permeable space separator which is stable to the aqueous or non-aqueous electrolyte selected from:
(i) depositing a substantially uniform in height array of electrically insulating discrete microprotrusions which are stable to an aqueous or non-aqueous 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,
(ii) placing a thin precut ion permeable electrically insulating separator having a thickness of between about 0.1 and 10 mil on one flat surface of the metal oxide layer;
(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 second electrically conducting material;
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 polymer is selected from the group consisting of polyimides, a polytetrafluoroethylene-trifluoroethylene copolymer, styrene-butadiene copolymer, polyethylenes, polypropylenes, polyolefins, polysulfone, fluorinated polymers, partly fluorinated polymers and 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 (T.sub.m) 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 about 5.degree. to 100.degree. C. greater than T.sub.m 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
(h) removing the at least one thin cord between each layer creating at least one small opening into the fill gap located between the porous electrode layers.

13 more elements

Dependencies are inferred from the claim text.

Energy storage device and its methods of manufacture

Life of this patent

Energy storage device and its methods of manufacture

Life of this patent

Abstract

Claims17