WO2016179508A2

WO2016179508A2 - Biocompatible water-deactivated batteries, systems and methods related thereto

Info

Publication number: WO2016179508A2
Application number: PCT/US2016/031239
Authority: WO
Inventors: Sumner A. Barenberg; Sally F. BARENBERG; Jeffrey M. Karp; Bryan Laulicht
Original assignee: Landsdowne Laboratories, Inc.
Priority date: 2015-05-07
Filing date: 2016-05-06
Publication date: 2016-11-10
Also published as: WO2016179508A3

Abstract

This invention relates to a battery comprising a water-activated switch that can deactivate a battery in the presence of water.

Description

Biocompatible Water-deactivated Batteries, Systems and Methods Related Thereto

REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No.

62/158,234, filed May 7, 2015, the contents of which are fully incorporated by reference herein.

BACKGROUND OF THE INVENTION

The widespread use of batteries to power many items including remote controls, flashlights, cameras, car key fobs, calculators, bathroom scales, reading lights, flameless candles, talking books, singing greeting cards, watches, thermometers, hearing aids, flashing jewelry, ornaments, games and toys creates an increased opportunity for ingestion. Children are particularly at risk to ingest batteries due to the accessibility and presence of these devices in the home. Recently, there was reported a nearly 7-fold increase in the percentage of reported button battery ingestions between 1985 and 2009.

Accidental ingestion has the strong potential for corrosive injury to the

gastrointestinal tract with major complications, including esophageal burns, fistula, or perforation. Due to the electrochemistry, batteries retained in the esophagus may cause extensive damage including serious injuries and even death. While ingestion of batteries creates an immediate choking hazard, prolonged injury is due in large part to an electrical current from the battery that generates hydroxide ions through an electrolysis reaction that occurs when the battery is in contact with tissue fluids, such as saliva. A battery lodged in the esophagus or elsewhere in the digestive tract can cause serious injuries in as little as two hours. See also, Int. J. Pediatr. Otorhinolaryngol., 77(9): 1392-1399 (2013).

Batteries that are less damaging when ingested are needed.

SUMMARY OF INVENTION

In one aspect the present invention provides a battery comprising an anode cap having an exterior face and interior face; a cathode housing; an electrolytic cell disposed in the cathode housing; a gasket joining the anode cap to the cathode housing, and an expanding element disposed in the cathode housing; wherein, in the absence of water, the anode cap is disposed in a first position in which the anode cap is in electrical communication with the electrolytic cell, forming a conductive pathway between the anode cap and the electrolytic cell; and wherein, upon exposure of the battery to water, water enters the battery and activates the expanding element, shifting the anode cap to a second position in which the anode cap is not in electrical communication with the electrolytic cell, thereby interrupting the conductive pathway.

In certain embodiments, the anode cap has an annular edge extending from the interior face.

In certain embodiments, one or a plurality of passages in the anode cap allow water to enter the battery.

In certain embodiments, the gasket is water-permeable. In certain embodiments, one or a plurality of passages in the gasket allow water to enter the battery.

In certain embodiments the expanding element is disposed between the interior face of the anode cap and the electrolytic cell. In certain embodiments the expanding element is disposed between the annular edge of the anode cap and the cathode housing. In certain embodiments wherein the expanding element comprises a superabsorbent polymer. In certain embodiments the expanding element comprises a compound which readily converts to a gas, such as carbon dioxide.

In certain embodiments, the anode cap has an insulating region that shields the annular edge of the anode cap from electrical communication with electrolytic cell when the anode cap is in the second position and optionally when the anode cap is in the first position.

In certain embodiments, the cathode housing further comprises an annular flange that retains the annular edge when the anode cap is in the second position.

In certain embodiments, the battery comprises an indicator element that changes color upon exposure to water.

In certain embodiments, further comprising a conductive anode cover adjacent to the electrolytic cell.

In certain embodiments, the battery further comprises a radiopaque element, optionally disposed on the anode cap.

In certain embodiments upon exposure of the battery to water, the conductive pathway is interrupted within 2 hours of exposure, within 1 hour of exposure, within 30 minutes of exposure, within 15 minutes of exposure, within 10 minutes of exposure, or even within 5 minutes of exposure.

In certain embodiments, the battery is a button or a coin cell. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic cross-sectional view of a conventional button battery.

Figures 2A and 2B are schematic cross-sectional views of first and second positions of a water- deactivated battery comprising an expanding element disposed between an anode cap and an electrolytic cell, according to one embodiment.

Figures 3A and 3B are schematic cross-sectional views of first and second positions of a water- deactivated battery comprising a retaining element, according to one embodiment.

DETAILED DESCRIPTION

Figure 1 is a cross-sectional view schematically illustrating the structure of a conventional button battery. See also http://emedicine.medscape.com/article/774838- overview. As illustrated in Figure 1, a cathode housing having a closed end contains an electrolytic cell comprising a cathode layer, an electrolyte-soaked separator, and an anode. A seal or gasket holds an anode cap to the cathode casing. In addition, the seal electrically insulates the anode cap from the cathode housing. The electrolyte-soaked separator creates a barrier between the cathode and anode, preventing them from touching while allowing electrical charge to flow freely between them. When a load completes the circuit across the conductive anode cap and the cathode housing, the battery produces electricity through a series of electrochemical reactions between the anode, cathode and electrolytes.

The invention provides a battery in which the anode cap can move relative to the cathode housing, such that, in an active state, the anode cap is disposed in a first position in which the anode cap is in electrical communication with the electrolytic cell; and exposure of the battery to an aqueous environment activates an expanding element to shift the anode cap to a second position in which the anode cap is not in electrical communication with the electrolytic cell, thereby interrupting a conductive pathway between the anode cap and the electrolytic cell. In this way, the battery is deactivated when placed in an aqueous environment, such as the digestive tract of a mammal.

Figure 2 depicts one embodiment of a button or coin battery in accordance with the invention. The battery includes a cathode housing comprising an electrolytic cell that includes an anode, an electrolyte separator, and a cathode. The battery also includes a gasket that joins the anode cap to the cathode housing. In certain embodiments, the gasket is a compressible gasket. The anode cap that has a passage, optionally comprising a water- permeable element, and an expanding element disposed between the anode cap and the electrical cell, as shown in Figure 2A. Though one passage is depicted in Figure 2A, in certain embodiments, a plurality of passages may be present. The one or more passages may be of any suitable size or shape to accomplish the functions described herein, and may be the same as or different from each other.

In certain embodiments, the anode cap has an insulating region that shields an annular edge of the anode cap from electrical communication with electrolytic cell when the anode cap is in the second position and optionally when the anode cap is in the first position

As seen in Figure 2A, the anode cap may comprise a protruding element extending from the interior face towards the electrolytic cell. In the active state, (i.e., in the absence of water), the protruding element is in electrical communication with the electrolytic cell.

When such a battery is placed in an aqueous environment, however, water may enter the battery through the water-permeable element and contact the expanding element. Upon contact with water, the expanding element expands, forcing the anode cap to a second position as represented in Figure 2B. In the second position, the protruding element of the anode cap is no longer in electrical communication with the electrolytic cell.

In certain embodiments, an anode slurry cover may be present and is positioned between the anode and the expanding element as depicted in Figure 2. An anode slurry cover may be necessary in some embodiments when the anode is not mechanically constrained in the absence of a cover, if the anode is not anchored to the separator, or if the anode is sensitive to the environment of the expanding element. Additionally or alternatively, the battery may include a water-impermeable barrier that prevents water that enters the batter and contacts the expanding element from contacting the battery chemistry or filling the gap that forms between the protruding element and the electrolytic cell, which could re-establish electrical communication.

Figure 3 depicts another embodiment of a battery of the invention, comprising a compressible and/or water-permeable gasket joining an anode cap to a cathode housing. As seen in Figure 3A, the gasket holds the anode cap in a first position such that the anode cap is in electrical communication with the electrolytic cell. The gasket may be porous, may have channels for water to pass through, or may define a passage that allows water to enter the battery. Alternatively or additionally, the gasket may comprise water-soluble inclusions that dissolve when the battery is placed in an aqueous environment, thereby opening passages for water to enter the battery.

The battery further comprises an expanding element positioned longitudinally between the anode cap and the cathode housing. When this battery is placed in an aqueous environment, water passes through the water-permeable gasket and contacts the expanding element. Upon contact with water, the expanding element expands, exerting force on the anode cap and shifting the anode cap to the second position as shown in Figure 3B. In the second position, the anode cap is not in electrical communication with the electrolytic cell.

Figure 3 also depicts an optional retaining member suitable for retaining the anode cap when the anode cap is in the second position. As seen in Figure 3, the retaining member is a flange on the upper portion of the cathode housing near the gasket and water permeable element. When the anode cap is in the second position, an annular edge of the anode cap may contact the flange on the cathode housing, blocking further motion of the anode cap and preventing the battery from coming apart. While depicted in conjunction with this embodiment, a retaining member, such as this flange, can be used with any of the embodiments disclosed herein to ensure that the contents of the battery are not released or exposed when the expanding element is activated.

In certain embodiments, the expanding element comprises a polymer with a high swelling capacity, such as a superabsorbent polymer. Superabsorbent polymers (also known as hydrogels, hydrocolloids, osmetics and absorbent gelling materials) are generally capable of absorbing large quantities of fluids such as water. Superabsorbent polymers have the property of expanding essentially isotropically in all three directions in space when aqueous liquids are absorbed. In some embodiments, the polymers expand in each direction by a factor of from 2 to 5, so that a total increase in volume of a factor from 8 to 125 may be observed. Superabsorbent polymer materials typically have the ability to absorb and retain, under moderate pressures, such fluids in an amount of at least about 10 times, preferably at least about 15 times, most preferably at least about 50 times, the dry weight of the polymer material. Examples of superabsorbent polymers include, but are not limited to, poly-acrylic acid, polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxymethylcellulose, polyvinyl alcohol copolymers, and cross-linked polyethylene oxide. Additional examples include the superabsorbent polymers used in children' s toys (see e.g., U. S. Patent No. 6,503,582) and the superabsorbent polymer used in fire retardant gels and foams (see e.g., U.S. Patent Nos. 7,992,647, 7,670,513 and 5,087,513), the disclosures of which are hereby incorporated by reference. In certain embodiments, the expanding element is formulated to be resistant to hot and humid environments and to be stable at high temperature and high humidity without expanding.

In certain embodiments, the expanding element comprises a compound which readily converts to a gas, such as carbon dioxide. For example, the expanding element may comprise separately encapsulated sodium bicarbonate and an acid (e.g., hydrochloric acid, citric acid) that, when exposed to water, mix to form carbon dioxide. The release of carbon dioxide may exert sufficient force to shift the anode cap from a first position to a second position. In the second position, the anode cap is no longer in electrical communication with the electrolytic cell thus deactivating the battery.

In certain embodiments, the expanding element may have foaming or dispersing properties. Suitable foaming and dispersing agents for use in this invention include, without limitation, any foaming agent suitable for foaming aqueous solutions, such as detergents, amphiphiles, 2-component polyurethane or polyethylene foams that have a water soluble barrier between the two components, 1-part foams that are already formed that are compressed to occupy less volume inside a water-soluble matrix that dissolves allowing them to expand. In certain embodiments, foaming agents include, but are not limited to, sodium lauryl ether sulfate, sodium dodecyl sulfate, and ammonium lauryl sulfate.

In certain embodiments, the battery further comprises a porous, conductive layer, e.g., disposed on the interior face of the anode cap. The porous, conductive layer includes regions of the expanding element such that the conductive layer is in electrical communication with adjacent elements of the battery, completing a conductive pathway between the anode cap and the electrolytic cell. Exposure of the battery to water activates the expanding element, breaking the electrical communication with the elements adjacent to one or both sides of the layer, thereby interrupting the conductive pathway and deactivating the battery. For example, the conductive layer could be a mesh formed of conductive wires with the expanding element disposed in the interstices of the mesh at a thickness less than or equal to the thickness of the wires or of the mesh, allowing electrical contact with the mesh from both sides. On contact with water, the expanding element may expand to be thicker than the thickness of the mesh, breaking electrical contact with the mesh from one or both sides and thus deactivating the battery.

In certain embodiments, the gasket and/or the expanding element may further comprise a hydrophilic agent, such as hydrophilic fibers, that may facilitate distribution of the water to and/or through the expanding element, and thus fostering activation of the expanding element. The hydrophilic agent may transport the water by a wicking process, in which a spontaneous transport of the liquid is driven through pores and spaces in the agent by capillary forces.

In certain embodiments, the battery may comprise an indicator element that when exposed to water changes color, e.g., disposed in the water-permeable gasket or on an exterior surface of the battery. In certain embodiments, the indicator element may be water- soluble such that it is released from the battery when the battery contacts water. In certain embodiments, the indicator element may be capable of leaching from the battery when the battery is in an aqueous environment and that, when ingested by a mammal, dyes the urine of the mammal a distinctive (e.g., non-yellow) color. Examples of indicator elements include, but are not limited to, Yellow No. 5, β-carotene, rifampin, Yellow No. 6, tetracycline, Red No. 40, Red No. 3, Blue No. 2, Evan's Blue, Green No 3, Blue No. 1, methylene blue, indocyanine green, Betanin, and beet juice (or anthocyanines or other food-based dyes), and combinations thereof.

In certain embodiments, the battery further comprises a radiopaque material disposed in or on the battery, e.g., presenting a distinctive shape, sign, or pattern. For example, a marking may be placed on the anode cap, the cathode housing, or any other suitable part of the housing, to allow a treating physician to ascertain via X-ray imaging whether the type of battery swallowed is one according to this invention, i.e., presents a less urgent medical issue than a conventional-type battery, or simply to distinguish a battery from a similarly-shaped object such as a coin. In certain embodiments, the radiopaque material may be disposed in the gasket. Radiopaque material is any material applied that is not transparent to X-rays or other forms of radiation and can be distinguished from the material that forms the anode cap and/or the cathode housing in an X-ray image. Examples of radiopaque materials include, but are not limited to, tungsten, tungsten dioxide, tungsten trioxide, stainless steel powder, silver iodide, iodinated organic compounds, gold, nickel alloys, titanium, tantalum, iodine and barium, and salts thereof and radiopaque polymers. In certain embodiments, the radiopaque marker may be defined by altering the radiopacity of the battery, e.g., by etching (e.g., via laser or chemically) or by machining away material from the cathode housing or anode cap. In certain embodiments, the radiopaque material (e.g., a sheet, a sphere, or any other two- or three-dimensional object) may be located within the battery, e.g., disposed between the anode cap and the cathode housing.

In certain embodiments, the gasket comprises a substance capable of neutralizing or absorbing hydroxide ions, such as an acid, a buffer, a base-sensitive polymer (such as an enteric polymer or a polyester), activated charcoal, or zeolites.

In certain embodiments, upon contact with water, the battery is deactivated within 2 hours of contact, preferably within 1 hour of contact, more preferably within 30 minutes of contact, more preferably within 15 minutes of contact, more preferably within 10 minutes of contact, and preferably within 5 minutes of contact, even more preferably within 1 minute of contact. In certain embodiments, the battery further comprises an aversive agent. For example, the aversive agent may be disposed in the gasket or on an external surface of the battery. Various aversive agents can be employed including, for example and without limitation, natural, artificial and synthetic flavor oils and flavoring aromatics and/or oils, oleoresins and extracts derived from plants, leaves, flowers, fruits, and so forth, and combinations thereof. Nonlimiting representative flavor oils include spearmint oil, peppermint oil, eucalyptus oil, oil of nutmeg, allspice, mace, oil of bitter almonds, menthol and the like. Also useful aversive agents are artificial, natural and synthetic fruit flavors such as citrus oils including lemon, orange, lime, grapefruit, and fruit essences and so forth. Additional aversive agents include sucrose derivatives (e.g., sucrose octaacetate), chlorosucrose derivatives, quinine sulphate, and the like. Additional aversive agents that may pungent properties include but are not limited to capsaicin, piperine, allyl isothiocyanate, and resinferatoxin. An exemplary commercially available aversive agent includes Denatonium Benzoate NF-Anhydrous, sold under the name Bitterant-b, BITTER+PLUS, Aversion, or Bitrex™ (Macfarlan Smith Limited, Edinburgh, UK).

In certain embodiments, the battery may also comprise a metal chelating agent. For example, the metal chelating agent may be disposed in the gasket or on an external surface of the battery. By way of non-limiting example, suitable chelating agents include aconitic acid, alanine diacetic acid (ADA), alkoyl ethylene diamine triacetic acids (e.g., lauroyl ethylene diamine triacetic acids (LED3A)), aminotri(methylenephosphonic acid) (ATMP), aspartic acid diacetic acid (ASDA), aspartic-N-monoacetic acid, diamino cyclohexane tetraacetic acid (CDTA), citraconic acid, citric acid, 1,2-diaminopropanetetraacetic acid (DPTA-OH), 1,3- diamino-2-propanoltetraacetic acid (DTP A), diethanolamine, diethanol glycine (DEG), diethylenetriaminepentaacetic acid (DTP A), diethylene triamine pentamethylene phosphonic acid (DTPMP), diglycolic acid, dipicolinic acid (DP A), ethanolaminediacetic acid, ethanoldiglycine (EDG), ethionine, ethylenediamine (EDA), ethylenediaminediglutaric acid (EDDG), ethylenediaminedi(hydroxyphenylacetic acid (EDDHA),

ethylenediaminedipropionic acid (EDDP), ethylenediaminedisuccinate (EDDS),

ethylenediaminemonosuccinic acid (EDMS), ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetrapropionic acid (EDTP), ethyleneglycolaminoethylestertetraacetic acid (EGTA), gallic acid, glucoheptonic acid, gluconic acid, glutamic acid diacetic acid (GLDA), glutaric acid, glyceryliminodiacetic acid, glycinamidedisuccinic acid (GADS),

glycoletherdiaminetetraacetic acid (GEDTA), 2-hydroxyethyldiacetic acid,

hydroxy ethylenediaminetriacetic acid (ITEDTA), hydroxy ethyldiphosphonic acid (FIEDP), 2- hydroxy ethyl imino diacetic acid (HIMDA), hydroxyiminodiacetic acid (HIDA), 2-hydroxy propylene diamine disuccinic acid (HPDDS), iminodiacetic acid (IDA), iminodisuccinic acid (IDS), itaconic acid, lauroyl ethylene diamine triacetic acids (LED3A), malic acid, malonic acid, methylglycinediacetate (MGDA), methyliminodiacetic acid (MID A),

monoethanolamine, nitrilotriacetic acid (NTA), nitrilotripropionic acid (NPA), N- phosphonomethyl glycine (glyphosate), propyldiamine tetraacetic acid (PDTA), salicylic acid, serinediacetic acid (SDA), sorbic acid, succinic acid, sugars, tartaric acid, tartronic acid, triethanolamine, triethylenetetraamine, triethylene tetraamine hexaacetic acid (TTHA), and combinations thereof.

In certain embodiments, the battery may have an aesthetically unappealing appearance. For example, the anode cap and/or the cathode housing may have a dull, dark (e.g., gray, black) color. In certain embodiments, the battery may have a non-glossy or matte finish.

Preferred embodiments of this invention are described herein with reference to the drawings. Of course, variations, changes, modifications and substitution of equivalents of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations, changes, modifications and substitution of equivalents as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Those of skill in the art will readily recognize a variety of non-critical parameters that could be changed, altered or modified to yield essentially similar results. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

While each of the elements of the present invention is described herein as containing multiple embodiments, it should be understood that, unless indicated otherwise, each of the embodiments of a given element of the present invention is capable of being used with each of the embodiments of the other elements of the present invention and each such use is intended to form a distinct embodiment of the present invention.

Incorporation by Reference

All publications and patents mentioned herein are hereby incorporated by reference in their entirety as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. In case of conflict, the present application, including any definitions herein, will control.

Equivalents

While specific embodiments of the subject invention have been discussed, the above specification is illustrative and not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of this specification and the claims below. The full scope of the invention should be determined by reference to the claims, along with their full scope of equivalents, and the specification, along with such variations.

Claims

What is claimed is:

1. A battery comprising:

an anode cap having an exterior face and interior face;

a cathode housing;

an electrolytic cell disposed in the cathode housing;

a gasket j oining the anode cap to the cathode housing, and

an expanding element disposed in the cathode housing;

wherein, in the absence of water, the anode cap is disposed in a first position in which the anode cap is in electrical communication with the electrolytic cell, forming a conductive pathway between the anode cap and the electrolytic cell; and wherein, upon exposure of the battery to water, water enters the battery and activates the expanding element, shifting the anode cap to a second position in which the anode cap is not in electrical communication with the electrolytic cell, thereby interrupting the conductive pathway.

2. The battery of claim 1, wherein the anode cap has an annular edge extending from the interior face.

3. The battery of any one of the preceding claims, wherein one or a plurality of passages in the anode cap allow water to enter the battery.

4. The battery of any one of the preceding claims, wherein the gasket is water- permeable.

5. The battery of claim 4, wherein one or a plurality of passages in the gasket allow water to enter the battery.

6. The battery of any one of the preceding claims, wherein the expanding element is disposed between the interior face of the anode cap and the electrolytic cell.

7. The battery of any one of claims 1-5, wherein the expanding element is disposed between the annular edge of the anode cap and the cathode housing.

8. The battery according to any one of the preceding claims, wherein the expanding element comprises a superabsorbent polymer.

9. The battery according to any one of the preceding claims, wherein the expanding element comprises a compound which readily converts to a gas.

10. The battery of claim 9, wherein the gas is carbon dioxide.

11. The battery of any one of the preceding claims, wherein the anode cap has an insulating region that shields the annular edge of the anode cap from electrical

communication with electrolytic cell when the anode cap is in the second position and optionally when the anode cap is in the first position.

12. The battery of any one of the preceding claims, wherein the cathode housing further comprises an annular flange that retains the annular edge when the anode cap is in the second position.

13. The battery of any one of the preceding claims, wherein the battery comprises an indicator element that changes color upon exposure to water.

14. The battery of any one of the preceding claims, further comprising a conductive anode cover adjacent to the electrolytic cell.

15. The battery of any one of the preceding claims, wherein the battery further comprises a radiopaque element, optionally disposed on the anode cap.

16. The battery of any one of the preceding claims, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 2 hours of exposure.

17. The battery according to any one of claims 1-15, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 1 hours of exposure.

18. The battery according to any one of claims 1-15, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 30 minutes of exposure.

19. The battery according to any one of claims 1-15, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 15 minutes of exposure.

20. The battery according to any one of claims 1-15, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 10 minutes of exposure.

21. The battery according to any one of claims 1-15, wherein upon exposure of the battery to water, the conductive pathway is interrupted within 5 minutes of exposure.

22. The battery of any one of the preceding claims, wherein the battery is a button or a coin cell.