Battery with safety mechanism

Abstract

To provide a battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis when the battery is exposed to aqueous solutions or wet tissue.SOLUTION: A battery 50 includes a housing having first and second poles. At least one electronic conductor 66 is electronically coupled to one of the first and second poles. A spacer 64 including an electronically insulating material is provided between the electronic conductor and the other of the first and second poles to prevent electronic coupling between the electronic conductor and the other of the first and second poles. The spacer is capable of undergoing a physical change in the presence of an aqueous solution to allow electronic coupling between the electronic conductor and the other of the first and second poles to occur.SELECTED DRAWING: Figure 2B

Description

[Technical Field]

[0001] The present disclosure relates to batteries, and more particularly to batteries with safety mechanisms designed to protect against tissue damage and / or electrolysis when the battery is exposed to aqueous solutions or wet tissue. [Background technology]

[0002] The background discussion provided herein is generally intended to provide a context for the present disclosure.

[0003] Electrochemical cells, often simply referred to as batteries, are commonly used as a source of electrical energy. Miniature batteries are particularly useful in powering consumer products. Miniature batteries come in a variety of cell types. Common miniature battery cell types include AAA, AA, B, C, D, 9V, CR2, and CR123A. Other types of miniature batteries known as button cells (including wider cells sometimes called coin cells) are frequently used to power a variety of products, including, but not limited to, watches, cameras, calculators, keyless entry systems for vehicles, laser pointers, glucometers, and the like.

[0004] FIG. 1 shows the structure of a typical button cell 10, with a cathode 12 disposed within a cathode can 14 and an anode 16 disposed within an anode cup 18. A separator 20 physically separates and electronically isolates the anode 16 from the cathode 12. An insulating gasket 22 serves to seal the cell to prevent electrolyte loss and to prevent the ingress of ambient atmospheric constituents into the cell, electronically insulating the cathode can 14 from the anode cup 18. Button cells typically have a long service life, e.g., well over a year of continuous use, typically in a wristwatch. Furthermore, most button cells have low self-discharge, thereby retaining their charge for relatively long periods of time when not under load.

[0005] While button cell batteries are common in many portable consumer electronic devices, the size, shape, and appearance of these batteries, particularly 20 mm diameter coin cells such as CR2016 and CR2032 lithium cells, can pose a particular risk to infants, young children, and pets. These risks can result in physical harm, especially if the cells are swallowed unknowingly. Furthermore, some of these button cell batteries may pose greater risks than others, risks that consumers may not fully understand. For example, 3V coin cell batteries, such as CR2016 3V lithium cells and CR2032 3V lithium cells, which are based on the chemical reaction between lithium and manganese dioxide, are sized such that they can easily become lodged in a person's throat. Therefore, if swallowed, they could cause electrolysis of bodily fluids and / or combustion of moist esophageal / organ tissue. Of course, such batteries can also cause significant gastric discomfort if successfully swallowed. Summary of the Invention [Means for solving the problem]

[0006] A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis is provided. The battery comprises a housing having first and second poles. At least one electronic conductor is electronically coupled to one of the first and second poles. A spacer comprising an electronically insulating material is provided between the electronic conductor and the other of the first and second poles to prevent electronic coupling between the electronic conductor and the other of the first and second poles. The spacer is capable of undergoing a physical change in the presence of an aqueous solution to allow electronic coupling between the electronic conductor and the other of the first and second poles to occur.

[0007] Further exemplary batteries with safety features are also provided that protect against tissue damage and / or electrolysis. The battery with the safety features includes a housing with first and second poles, an electronic conductor, and first and second spacers. The first and second spacers comprise electronically insulating materials. The first spacer is disposed between the first pole of the battery and the electronic conductor, and the second spacer is disposed between the second pole of the battery and the electronic conductor, with the electronic conductor being disposed between and in contact with the first and second spacers. The spacers are capable of undergoing a physical change in the presence of an aqueous solution, and the electronic conductor is configured to provide electronic contact with both the first and second poles in the presence of the aqueous solution.

[0008] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the invention, the present invention will be better understood from the following description taken in conjunction with the accompanying drawings. The figures described below depict various embodiments of the battery disclosed herein. It should be understood that each figure depicts an exemplary embodiment of the battery disclosed herein with safety mechanisms adapted to protect against tissue damage and / or electrolysis. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows a conventional button cell. [Figure 2A] 1 illustrates a battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis according to an exemplary embodiment according to the present disclosure. [Figure 2B] 1 illustrates a battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis according to an exemplary embodiment according to the present disclosure. [Figure 3]1 shows a plot of cell voltage versus time for two different batteries, the first being a conventional coin cell battery and the second being a coin cell battery with safety features designed to protect against tissue damage and / or electrolysis according to an exemplary embodiment of the present disclosure. [Figure 4A] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. [Figure 4B] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. [Figure 5A] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with a further exemplary embodiment of the present disclosure. [Figure 5B] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with a further exemplary embodiment of the present disclosure. [Figure 6A] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. [Figure 6B] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. [Figure 7] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. [Figure 8] 10 illustrates another battery in the form of a coin cell having a safety mechanism adapted to protect against tissue damage and / or electrolysis in accordance with another exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The electrochemical cell or battery may be a primary battery or a secondary battery. A primary battery is intended to be discharged, for example, once to exhaustion and then discarded. Primary batteries are described, for example, in David Linden's Handbook of Batteries (McGraw-Hill, 4th ed., 2011). Secondary batteries are intended to be charged. Secondary batteries can be discharged and then recharged many times, for example, more than 50 times, more than 100 times, or more than 1000 times. Secondary batteries are described, for example, in David Linden's Handbook of Batteries (McGraw-Hill, 4th ed., 2011). Batteries may include aqueous or non-aqueous electrolytes. Thus, batteries may include various electrochemical combinations and electrolyte combinations. Consumer batteries can be either primary batteries or secondary batteries. However, due to the charge stored in the battery and due to the exposed poles, it is beneficial to protect consumer batteries, particularly small consumer batteries, from injury to the consumer when exposed to moist tissue. In particular, it is beneficial to protect the battery from exposing the consumer to electrolysis or burns, both of which could occur, for example, if the battery were swallowed. In this regard, if the positive and negative poles of a battery are exposed to moist bodily fluids, electrolysis of water can occur, resulting in the development of hydroxide ions and burning of tissue adjacent to the negative pole, and potentially causing direct oxidation of tissue, particularly tissue adjacent to the positive pole (or cathode can). In addition, significant oxidation of the cathode can itself can result in the formation of holes in the cathode can, which can release the battery's toxic contents. The present application provides a safety mechanism for short-circuiting a battery in the presence of an aqueous solution. By short-circuiting a battery in the presence of an aqueous solution, the disclosed safety mechanism advantageously reduces the cell voltage of a swallowed battery, thereby effectively preventing tissue damage and other harmful effects caused by uncontrolled discharge of the swallowed battery.

[0011] A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis is provided. The battery includes a battery housing with first and second poles. At least one electronic conductor is electronically coupled or in electronic contact with one of the first and second poles. It should be noted that the terms "electronically coupled" and "electronic contact" are used interchangeably herein to describe a relationship in which electrons can flow between the listed components. The electronic conductor may be electronically coupled to one of the first and second poles because the electronic conductor is in direct physical contact with the pole. Alternatively, one or more additional intervening electronically conductive materials may be present between the electronic conductor and one of the first and second poles.

[0012] A spacer comprising an electronically insulating material is provided between the electronic conductor and the other of the first and second poles to prevent electronic coupling between the electronic conductor and the other of the first and second poles, and the spacer is capable of undergoing a physical change (including, but not limited to, a chemical change resulting in a change in physical properties) in the presence of an aqueous solution to allow electronic coupling between the electronic conductor and the other of the first and second poles to occur.

[0013] In general, the present disclosure provides batteries that can be mechanically and / or electronically shorted by electronically coupling or forming an electronic connection across both battery poles. The electronic connection across the positive and negative battery poles is formed only after the battery is exposed to a “safe condition,” which refers to the ambient conditions encountered when a battery becomes lodged in the throat of a person, child, or pet animal. In these situations, if a person, child, or pet animal swallows the battery, the battery may come into contact with saliva, gastric juices, or other aqueous fluids. Therefore, batteries with safety mechanisms designed to protect against tissue damage and / or electrolysis are configured and designed to short circuit when in the presence of an aqueous solution. The resulting short circuit reduces the battery's voltage below a desired threshold level, thereby reducing and / or effectively preventing water electrolysis and the associated formation of harmful electrochemically generated ions (e.g., hydroxide ions). The desired threshold level can vary, but in some examples detailed herein, the cell may be suitably shorted to less than 1.5 V, including less than 1.4 V, less than 1.3 V, less than 1.2 V, less than 1.1 V, less than 1.0 V, less than 0.9 V, less than 0.8 V, less than 0.7 V, less than 0.6 V, less than 0.5 V, less than 0.4 V, less than 0.3 V, less than 0.2 V, less than 0.1 V, or even to about 0 V. Under "normal use conditions," when the battery is not in use, e.g., when the battery is stored or transported, or when the battery is operating in an electronic device, no electronic connection is formed and shorting of the battery is avoided.

[0014] In one embodiment, a battery according to the present disclosure includes an electronic conductor that is initially in electronic contact with only one of the first and second poles of the battery. A spacer comprising an electronically insulating material prevents the electronic conductor from making electronic contact across both battery poles under normal use conditions (i.e., before the battery is contacted with an aqueous solution). However, when the battery is exposed to or comes into contact with an aqueous solution, such as saliva, gastric juice, water, or other aqueous fluids, the electronically insulating material may undergo a physical change, such as dissolution, because the electronically insulating material dissolves in aqueous fluids. The electronic conductor is biased toward electronic contact with the other pole of the battery, but the resistive force of the spacer is equal to or greater than the biasing force of the electronic conductor under normal use conditions. However, after substantial dissolution of the electronically insulating material, such resistive force is substantially absent, and the electronic conductor may make electronic contact with the other pole of the battery, thereby shorting the battery. The electron conductor may be energized, for example, during crimping of the cathode can (or an extension thereof) and / or during crimping of an electron conductor that is a separate, discrete component from the cathode can.

[0015] In another example, a battery according to the present disclosure also includes an electronic conductor that is initially in electronic contact with only one of the first and second poles of the battery. The spacer, which includes an electronically insulating material, prevents the electronic conductor from making electronic contact across both battery poles under normal use conditions (i.e., before the battery is contacted with an aqueous solution). However, when the battery is exposed to or comes into contact with an aqueous solution, such as saliva, gastric juice, water, or other aqueous fluids, the electronically insulating material may undergo a physical change, e.g., the electronically insulating material may swell and / or soften in the presence of aqueous fluids. This is because the electronically insulating material includes a polymer that swells when exposed to an aqueous solution. The electronic conductor is biased toward electronic contact with the other pole of the battery, but the resistance force of the spacer is greater than or equal to the bias force of the electronic conductor under normal use conditions. However, after the swelling and / or softening of the electronically insulating material, the resistance force of the spacer is significantly reduced, which may result in mechanical deformation, distortion, or displacement of the spacer. This is because the biasing force of the electronic conductor would "override," distort, or displace the electronically insulating material of the spacer, thereby creating an electronic connection between the two poles and shorting the battery. In one refinement, the electronically insulating material is a hydrogel that, in the presence of an aqueous fluid, forms a gel that cannot resist the biasing force exerted by the electronic conductor. The electronic conductor may be biased, for example, during crimping of the cathode can (or an extension thereof) and / or during crimping of an electronic conductor that is a separate, individual component from the cathode can.

[0016] By way of example, the electronic conductor herein may be formed from a metal, e.g., the electronic conductor may be formed from any suitable electronically conductive material. Electronically conductive materials suitable for forming the electronic conductor include, but are not limited to, (i) metal alloys, including, but not limited to, steel, such as stainless steel, nickel-plated steel, or zinc-plated steel; (ii) conductive ceramics, including, but not limited to, carbides, oxides, nitrides, and combinations of the foregoing; (iii) conductive polymers; and (iv) conductive composites, and any combination thereof. The electronic conductor may be energized, for example, during crimping of the cathode can (or an extension thereof) and / or during crimping of an electronic conductor that is a separate, discrete component from the cathode can.

[0017] The electron conductors disclosed herein generally have a conductivity of about 5×10 at 20° C. -5 ohm cm or less than 2.5 x 10 at 20 °C -5 Less than ohm cm, or approximately 0.5 x 10 at 20°C -5 Approximately 5 × 10 ohm·cm at 20°C -5 The electronic conductor has a resistance of ohm·cm. In some examples, the resistance of the electronic conductor is less than 20 ohms, less than 10 ohms, or less than 5 ohms, e.g., the resistance may be about 10 ohms, about 5 ohms, or about 1 ohm. In some examples, the resistance of the electronic conductor is between about 0.1 ohms and about 20 ohms.

[0018] The resistance of the electronic insulating material is always greater than the resistance of the electronic conductor. In some examples, the resistance of the electronic insulating material is greater than 0.5 megaohms, greater than 5 megaohms, greater than 10 megaohms, greater than 100 megaohms, or greater than 500 megaohms. For example, the resistance of the electronic insulating material may be about 1 megaohm, about 20 megaohms, about 200 megaohms, or about 1000 megaohms. In some examples, the resistance of the electronic conductor is between about 0.5 megaohms and about 1000 megaohms.

[0019] The electronically insulating material of the spacer can be formed from any number of electronically insulating materials (including, but not limited to, electronically insulating materials that undergo a chemical change leading to a change in physical properties) that can undergo a physical change in the presence of water, including, but not limited to, suitable water-softening materials, suitable water-soluble and / or water-swellable materials. As used herein, the term "water-softening" refers to a material that has a Young's modulus that decreases in the presence of an aqueous solution. Useful water-softening materials have a Young's modulus that is high enough to provide a resistive force greater than the biasing force of the electronic conductor under normal use conditions. Useful water-softening materials also have a Young's modulus that is low enough to allow the material to deform sufficiently after the presence of an aqueous solution when the biasing force of the electronic conductor is applied to the water-softening material, thereby providing an electronic bond between the electronic conductor and the other of the first and second battery poles. Useful water-softening materials also generally have a Young's modulus that decreases after the presence of an aqueous solution, to a range of 0.0003 to 0.15 GPa. Various testing systems, such as the 8802 servo-hydraulic testing system available from Instron, can be used to determine the elastic modulus. The water-softening material may be a water-soluble material. Useful water-soluble materials have a water solubility of greater than 50 mg / L, greater than 100 mg / L, greater than 500 mg / L, or even greater than 1000 mg / L. Useful water-swellable materials generally have a water solubility of greater than 30 wt.% in pure water, preferably at least 100 wt.% in water. Useful water-swellable materials allow the material to deform sufficiently when, in the presence of an aqueous solution, a biasing force of an electronic conductor is applied to the water-swellable material, thereby providing an electronic bond between the electronic conductor and the other of the first and second battery electrodes.

[0020] The electronically insulating material may be present in an amount of 5 wt.% to 100 wt.%, for example, 10 wt.% to 99 wt.%, 50 wt.% to 99 wt.%, and / or 70 wt.% to 99 wt.%, based on the weight of the spacer (i.e., based on the weight of the solids used to provide the spacer). Any number of water-softening, water-soluble, and / or water-swellable polymers may be used alone or in combination to form the spacer. Non-limiting examples of water-soluble, water-soluble, and / or water-swellable materials include, but are not limited to, sugars, polyethers such as polyethylene glycol (PEG) and polyethylene oxide (PEO), polyacrylic acid (PAA), polyamides (PA), polyacrylates, polyvinyl alcohol and modified polyvinyl alcohols, acrylate copolymers, polyvinylpyrrolidone, pullulan, gelatin, carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose, polysaccharides, natural polymers including, but not limited to, agar, guar gum, xanthan gum, locust bean gum, carrageenan, and starch, modified starches including, but not limited to, ethoxylated starch and hydroxypropylated starch, copolymers of the foregoing, salts thereof, and combinations of any of the foregoing. The water-softening, water-soluble, and / or water-swellable material is preferably a biologically inert material with no or little toxicity.

[0021] Benign solids such as NaHPO, sodium chloride (NaCl), potassium chloride (KCl), baking soda, sugar, sugar-like substances, and citric acid may be included in combination with the electronically insulating material to provide a spacer. The benign solids may be present in an amount of 0 wt.% to 30 wt.%, e.g., 0 wt.% to 20 wt.%, 1 wt.% to 30 wt.%, and / or 1 wt.% to 20 wt.%, based on the weight of the spacer (i.e., based on the weight of the solids used to provide the spacer).

[0022] 2A and 2B show a battery 50, which may be any type of primary or secondary battery, and in the illustrated example is a button cell type battery. The battery 50 includes a battery housing that encloses the battery. The battery housing includes a cathode can 54 and an anode cup 58. A cathode 52 is disposed within the cathode can 54, and an anode 56 is disposed within the anode cup 58. The cathode 52 and the anode 56 are electrically separated by a separator 60 within the battery 50. The cathode can 54 and the anode cup 58 each form a different pole of the battery 50, with the cathode can 54 forming the positive pole and the anode cup 58 forming the negative pole.

[0023] The cathode 52 and anode 56 are separated by an insulating separator 60 that extends across the entire lateral extent of the cathode 52, e.g., substantially the entire diameter of the battery 50. The insulating separator 60 is fabricated from a material that can freely conduct ions therethrough. An insulating gasket 62 electronically insulates the cathode can 54 from the anode cup 58, and the insulating gasket 62 prevents any part of the anode cup 58 from contacting the cathode can 54, sealing the battery 50 and preventing electrolyte loss.

[0024] In the illustrated embodiment, the insulating gasket 62 extends into the cathode can 54 and completely surrounds the anode cup 58 so that the anode cup cannot contact the cathode can 54; however, the opposite configuration may also be used, in which the anode cup 58 surrounds the cathode can 54 and the insulating gasket 62 extends into the anode cup 58 and completely surrounds the cathode can 54. While each of the illustrated embodiments explicitly shown herein (including those shown in FIGS. 2A, 2B, 4A, 4B, 5A, 5B, 6A, and 6B) includes an insulating gasket 62 (or corresponding reference number) that extends into the cathode can 54 (or corresponding reference number) and completely surrounds the anode cup 58 (or corresponding reference number) so that the anode cup cannot contact the cathode can 54 (or corresponding reference number), it should be understood that batteries with safety mechanisms in which the opposite configuration is used are contemplated.

[0025] The battery 50 further includes an exemplary safety feature adapted to protect against tissue damage and / or electrolysis according to the present disclosure, which includes an electronic conductor 66 extending entirely or partially around the outer edge of the cathode can 54. The electronic conductor 66 may be formed from a metal, such as a metal alloy material, as previously described. The electronic conductor 66 includes an attachment segment 68 that is fixedly attached to the outer surface of the cathode can 54. The electronic conductor 66 may be attached to the cathode can by any suitable interconnection. For example, the attachment segment 68 may be attached by an interference fit with a groove (not shown) along the outer wall of the cathode can 54 for a mechanically secure attachment. In other examples, the attachment segment 68 may be attached to the outer wall of the cathode can 54 by applying an adhesive or by forming a welded joint.

[0026] In the reverse configuration (not shown, but briefly described above) in which insulating gasket 62 extends into anode cup 58 and surrounds cathode can 54 so that the cathode can cannot contact anode cup 58, electronic conductor 66 may extend wholly or partially around the outer edge of anode cup 58 and be secured to the anode cup as described above in connection with cathode can 54.

[0027] 2B, the attachment segment 68 of the electron conductor 66 is electronically coupled to the cathode can 54. In the illustrated configuration, the electron conductor 66 is in direct physical contact with the cathode can 54. The electron conductor 66 further includes a ground segment 70 extending from the attachment segment 68. Generally, the ground segment 70 extends in a direction perpendicular or nearly perpendicular to the attachment segment 68.

[0028] The ground segment 70 is spaced from the anode cup 58 during normal operation of the battery 50, thereby preventing the positive and negative poles from being electronically coupled during normal operation of the battery 50 and, as a result, preventing the battery 50 from shorting out. In the illustrated example, the spacing between the ground segment 70 and the anode cup 58 is achieved by providing a spacer 64 comprising an electronically insulating material between the ground segment 70 and the anode cup 58. As shown in FIG. 2B , the spacer is disposed between the overhang of the ground segment 70 and the other of the first and second poles, here the anode cup 58, such that the ground segment 70 of the electronic conductor 66 is not electronically coupled to the anode cup 58 (and therefore the negative pole of the battery 50) when the spacer 64 is present, as during normal use. The spacer 64 may extend up to or beyond the overhang of the ground segment 70.

[0029] The spacer 64 may comprise a material that can undergo a physical change, for example, by dissolving after exposure to a safe condition, typically saliva, gastric fluids, or other aqueous fluids, such that after dissolving the spacer 64, the biasing force of the electronic conductor 66 can place the ground segment 70 in electronic contact with the anode cup 58 (e.g., its upper top surface or sidewall surface) to short-circuit the battery 50. In other examples, the spacer 64 may comprise a material that can be overcome, distorted, or displaced, for example, because the spacer 64 softens, swells, or otherwise mechanically weakens in response to exposure to a safe condition, typically saliva, gastric fluids, or other aqueous fluids. The spacer 64 may be mechanically weakened, for example, when aqueous fluids contact the battery 50 and are absorbed by the spacer 64, causing the spacer 64 to soften, swell, and / or form a gel. As a result of such mechanical weakening of the spacer 64, the biasing force of the electronic conductor 66 can cause the ground segment 70 to engage and make electronic contact with the anode cup 58, thereby shorting out the battery 50, for example, during a safe condition (or other contact of the battery 50 with aqueous fluid). As previously mentioned, a safe condition may occur when a person, infant, or pet animal swallows the battery 50, exposing the battery 50 to aqueous fluids in the form of saliva or gastric juices. In the illustrated embodiment, the insulating gasket 62 is shown as a separate component from the spacer 64, so that it can remain intact after the battery 50 comes into contact with aqueous fluid and the spacer undergoes a physical change, thereby maintaining the cathode 52 and anode 56 materials within the battery 50. However, in other embodiments, the insulating gasket 62 and spacer 64 can form a unitary structure, in which case the spacer 62 also functions as, and effectively provides, the insulating gasket 64. Thus, in this embodiment, there is no separate insulating gasket 64, and the spacer 62, which comprises an electronically insulating material, in addition to being positioned between the ground segment 70 and the anode cup 58, also extends into the cathode can 54 and completely surrounds the anode cup 58 so that the anode cup 58 cannot contact the cathode can 54.Of course, as mentioned above, it is contemplated that batteries with safety mechanisms may be used in the reverse configuration.

[0030] 2B, the electronic conductor 66 includes two segments: a mounting segment 68 and a ground segment 70. Each segment 68, 70 is electronically coupled to a first pole of the battery 50 (e.g., the cathode can 54), and each segment 68, 70 is electronically insulated from a second pole of the battery 50 (e.g., the anode cup 58) by a spacer 64. In the illustrated embodiment, the mounting segment 68 is electronically coupled to (and in fact makes direct physical contact with) the cathode can 54, i.e., the positive battery pole, and the ground segment 70 of the electronic conductor 66 is not in electronic contact with the anode cup 58, i.e., the negative battery pole, but is biased toward engagement with the anode cup 58.

[0031] It is understood that either the positive or negative pole of the battery 50 may be electronically connected to the electronic conductor 66, with the other of the two poles being electronically insulated from the tensioned electronic conductor 66 under normal use or storage conditions. Accordingly, it is further understood that a spacer 64 may be disposed adjacent to either the positive or negative pole of the battery 50 to prevent electronic contact between the electronic conductor 66 and either the positive or negative pole of the battery 50 under normal use or storage conditions. Accordingly, it is also contemplated that the electronic conductor 66 may alternatively be disposed around the periphery of the battery 50 such that during normal use, the electronic conductor is electronically coupled (e.g., in direct physical contact) to the top surface of the anode cup 58 and spaced from the sidewall of the cathode can 54 by a spacer 64 disposed between the electronic conductor 66 and the cathode can 54.

[0032] Furthermore, although the illustrated example shows the mounting segment 68 and the ground segment 70 as being directly connected to one another so that they are integral and therefore continuously electronically coupled to one another, in other examples, the mounting segment 68 and the ground segment 70 of a battery safety mechanism (not shown) may be electronically insulated from one another during normal operation of the battery so that they are electronically coupled to one another only during a safety condition, such as in response to the presence of aqueous or bodily fluids. Thus, in other examples, the mounting segment 68 may be in electronic contact with either the positive or negative terminal of the battery 50, and the ground segment 70 may be in electronic contact with the other of the positive and negative terminals of the battery 50, in which case the spacer 64 comprises an insulating material positioned between the two segments 68, 70 such that the segments 68, 70 are not electronically coupled to one another (and therefore the positive and negative terminals are not electronically coupled to one another) during normal operation of the battery. After encountering a safety condition (or other contact between battery 50 and aqueous fluid) that results in dissolution, softening, and / or swelling of the electronically insulating material of spacer 64, grounding segment 70 can engage and make electronic contact with mounting segment 68, thereby shorting out battery 50. As previously mentioned, a safety condition can occur when a person, baby, or pet animal swallows battery 50, exposing battery 50 to aqueous fluids in the form of saliva or gastric juices.

[0033] FIG. 3 shows plots of cell voltage versus time for two different batteries: a conventional button cell battery (in this example, button cell battery DL2032 available from Duracell Inc.) and an equivalent button cell battery further equipped with safety features designed to protect against tissue damage and / or electrolysis according to the present disclosure, such as battery 50 depicted in FIGS. 2A and 2B. After approximately 100 seconds of contacting the battery with a 1 M KCl solution, gassing begins at anode cup 58, and the actual cell voltage of the tested battery drops as the battery begins to short. For the conventional battery, the voltage stops dropping to approximately 1.5 V after approximately 300 seconds. Although the voltage of 1.5 V is reduced, it is still sufficient to cause water electrolysis and the production of hydroxide ions. Therefore, even at this reduced voltage, the battery could cause esophageal tissue burning and damage if lodged in a human throat. Of course, the battery could also cause significant stomach distress if successfully swallowed. In contrast, a battery 50 with a safety mechanism designed to protect against tissue damage and / or electrolysis is further shorted so that water electrolysis substantially no longer occurs in the anode cup 58. Indeed, in the illustrated example, the safety mechanism substantially completely shorts the battery 50 to approximately 0 V. In the example shown in FIG. 3, a spacer 64 was used that included an electronically insulating material that was a water-soluble material that can be dissolved in saliva, gastric juice, or other aqueous fluids. Specifically, the spacer 64 of the battery 50 with the safety mechanism shown in FIG. 3 included a benign solid, in this case a benign salt, specifically NaHPO (approximately 10 wt.%), and a water-soluble material, specifically polyacrylic acid (approximately 90 wt.%).

[0034] 4A and 4B , another example battery 100, also referred to as a button cell battery, includes a cathode can 114 and an anode cup 118. A cathode 152 is disposed within the cathode can 114, and an anode 156 is disposed within the anode cup 118. The cathode 152 and the anode 156 are electronically separated by a separator 160 within the battery 100. Each of the cathode can 114 and the anode cup 118 forms a different pole of the battery 100, with the cathode can 114 forming the positive pole and the anode cup 118 forming the negative pole. An insulating gasket 162 electronically insulates the cathode can 114 from the anode cup 118 and prevents any part of the anode cup 118 from contacting the cathode can 114, sealing the battery 100 and preventing electrolyte loss. Battery 100 shares many of the same elements as those shown in connection with battery 50 described above in FIGS. 2A and 2B, and therefore, generally only the differences will be described herein.

[0035] Battery 100 further includes a safety mechanism adapted to protect against tissue damage and / or electrolysis, the safety mechanism comprising a spacer 164 and an electronic conductor 166 embedded or disposed within spacer 164, the spacer 164 comprising an electronically insulating material capable of undergoing a physical change after exposure to an aqueous solution, such as saliva, gastric juices, water, or other aqueous fluids. Spacer 164 is disposed above insulating gasket 162 and functions similarly to insulating gasket 162 during normal operation in that spacer 164 electronically insulates cathode can 114 from anode cup 118. In the illustrated example, electronic conductor 166 embedded or disposed within spacer 164 is in direct physical contact with one of the first and second battery poles, here anode cup 118, and is therefore electronically coupled to anode cup 118, but is electronically isolated from the other of the first and second battery poles, here cathode can 114, by spacer 164. In this example, electronic conductor 166 is electronically coupled to anode cup 118 at contact location 150. Similar to the electronic coupling between cathode can 54 and electronic conductor 66 illustrated in battery 50 shown in Figures 2A and 2B, the electronic coupling between electronic conductor 166 and anode cup 118 can be a predetermined, direct physical connection that is maintained throughout the operation of battery 100, both during normal operation and storage, and after battery 100 experiences a safety condition. The connection between electronic conductor 166 and anode cup 118 at contact location 150 can be secured by, for example, a welding operation or a mechanical connection.

[0036] In the illustrated embodiment, the electronic conductor 166 extends from the contact location 150 into two bifurcated arm segments that are biased toward engagement with the cathode can 114 across a portion of the distance between the anode cup 118 and the cathode can 114. While only a single electronic conductor 166 is shown in this example, more than one such electronic conductor 166 may be included. After contact with an aqueous solution, such as saliva, gastric juices, water, or other aqueous fluid, the spacer 164 dissolves, softens, and / or swells, thereby allowing the electronic conductor 166 to deflect into electronic contact with the cathode can 114, thereby electronically coupling the cathode can 114 to the anode cup 118. As a result, the battery 100 is short-circuited, protecting the consumer during a safety condition, such as if the battery 100 were swallowed by a person or pet animal. In the illustrated embodiment, insulating gasket 162 is shown as a separate component from spacer 164 so that it can remain intact after battery 100 comes into contact with aqueous fluid, thereby maintaining the cathode 152 and anode 156 materials within battery 100. However, in other embodiments, insulating gasket 162 and spacer 164 can form a unitary structure, in which case spacer 164 also functions as insulating gasket 162, effectively providing insulating gasket 162, as noted with respect to spacer 64 and insulating gasket 62 described above in connection with Figures 2A and 2B.

[0037] In this example, the electron conductor 166 may be partially or wholly embedded or disposed within the spacer 164, so long as the resistive force of the spacer 164 is equal to or greater than the biasing force of the electron conductor 166 so that the electron conductor does not bias into electronic contact with the cathode can 114 under normal use. It should be noted, therefore, that the electron conductor 166 may be biased toward engagement with the cathode can 114, e.g., the electron conductor 166 may be biased toward engagement with the inner surface of the cathode can 114. Of course, the opposite configuration is also contemplated, in which the electron conductor 166 is electronically coupled to the cathode can 114 by making direct physical contact therewith, while being electronically isolated from the anode cup 118 by the spacer 164.

[0038] 5A and 5B illustrate an exemplary battery 200 with a safety mechanism according to the present disclosure designed to protect against tissue damage and / or electrolysis. The battery 200 includes a cathode can 214 and an anode cup 218. A cathode 252 is disposed within the cathode can 214, and an anode 256 is disposed within the anode cup 218. The cathode 252 and the anode 256 are electronically separated by a separator 260 within the battery 200. The cathode can 214 and the anode cup 218 each form a different pole of the battery 200, with the cathode can 214 forming the positive pole and the anode cup 218 forming the negative pole. An insulating gasket 262 electronically insulates the cathode can 214 from the anode cup 218 and prevents any part of the anode cup 218 from contacting the cathode can 214, sealing the battery 200 and preventing electrolyte loss. Battery 200 shares many of the same elements as those shown in connection with battery 50 described above in FIGS. 2A and 2B, and therefore, generally only the differences will be described herein.

[0039] A first battery electrode, here cathode can 214, includes an electronic conductor 230 incorporated into cathode can 214 as a continuation or extension thereof. Thus, although electron conductor 66 is shown in FIG. 2B as a separate component from cathode can 54, electronic conductor 230 and cathode can 214 form an integral structure, e.g., electronic conductor 230 constitutes a continuation or extension of cathode can 214 that can be electronically coupled to a second battery electrode, here the outer surface of anode cup 218, to short-circuit battery 200 after the battery is exposed to an aqueous solution, such as saliva, gastric juice, water, or other aqueous fluid. Electronic conductor 230 may have a protrusion (not shown) that facilitates electronic contact with the outer wall of the other battery electrode, anode cup 218, after battery 200 experiences a safe condition.

[0040] 5A and 5B, the electronic conductor 230 of the cathode can 214 is separated from the anode cup 218 by a spacer 264 comprising an electronically insulating material. The spacer 264 is incorporated into the sealed area of the battery 200, and the spacer 264 is disposed between the electronic conductor 230 and the outer wall of the anode cup 218, thereby preventing electronic contact between the electronic conductor 230 and the anode cup 218. Under normal use, the spacer 264 may provide an additional seal to the battery 200, which also includes the common insulating gasket 262, as described above. The spacer 264 and the insulating gasket 262 cooperate to prevent electronic connection between the anode cup 218 and the cathode can 214, thereby electronically insulating these two components from each other under normal use. After the battery 200 is exposed to aqueous or bodily fluids, upon dissolution, softening, and / or swelling of the electronically insulating material of the spacer 264, the continuation or extension 230 of the cathode can 214 may be forced into engaging contact with the outer wall of the anode cup 218, thereby electronically coupling the continuation or extension 230 of the cathode can 214 to the anode cup 218. As a result, the battery 200 may be short-circuited, protecting the consumer during a safety condition, such as if the battery 200 is swallowed by a person or pet animal. In the illustrated embodiment, the insulating gasket 262 is shown as a separate component from the spacer 264, so that it can remain intact after the battery 200 comes into contact with aqueous fluids, thereby maintaining the cathode 252 and anode 256 materials within the battery 200. However, in other embodiments, the insulating gasket 262 and the spacer 264 may be of one unitary structure, in which case the spacer 264 further functions as the insulating gasket 262, effectively providing the insulating gasket 262, as noted with respect to the spacer 64 and the insulating gasket 62 described above in connection with Figures 2A and 2B.

[0041] Typically, the integral continuation or extension 230 of the cathode can 214 is formed during the crimping process when the battery 200 is manufactured. In the illustrated example, the continuation or extension 230 of the cathode can 214 is formed as an extension of the sidewall of the cathode can 214. The continuation or extension 230 includes a bend and is biased toward engagement with the anode cup 218. The continuation or extension 230 may be pre-cut, for example, to form a biased electronic conductor.

[0042] 6A and 6B show an exemplary battery 300 with a safety mechanism according to the present disclosure designed to protect against tissue damage and / or electrolysis. The battery 300 includes a cathode can 314 and an anode cup 318. A cathode 352 is disposed within the cathode can 314, and an anode 356 is disposed within the anode cup 318. The cathode 352 and the anode 356 are electronically separated by a separator 360 within the battery 300. The cathode can 314 and the anode cup 318 each form a different pole of the battery 300, with the cathode can 314 forming the positive pole and the anode cup 318 forming the negative pole. An insulating gasket 362 electronically insulates the cathode can 314 from the anode cup 318 and prevents any part of the anode cup 318 from contacting the cathode can 314, sealing the battery 300 and preventing electrolyte loss. Battery 300 shares many of the same elements as those shown in connection with battery 50 described above in FIGS. 2A and 2B, and therefore, generally only the differences will be described herein.

[0043] Battery 300 has features similar to those of batteries 100 and 200 (shown in FIGS. 3A, 3B, 4A, and 4B). As shown in FIG. 6B, battery 300 differs from battery 200 in that the safety mechanism includes a second electronic conductor 366, which may be embedded or disposed within a spacer 364 and may extend around the entire circumference of anode cup 318 or along only a portion of the circumference of anode cup 318. Second electronic conductor 366 is electronically coupled to anode cup 318 by making direct physical contact therewith, while being electronically isolated from first conductor 330, and thus cathode can 314, by spacer 364. After the battery 300 is exposed to an aqueous solution or bodily fluid, upon dissolution, softening, and / or swelling of the electronically insulating material of the spacer 364, the continuation or extension 330 of the cathode can 314 can be forced into engaging contact with the outer wall of the anode cup 318, thereby electronically coupling the continuation or extension 330 of the cathode can 314 to the anode cup 318. Additionally, after the battery comes into contact with an aqueous solution, such as saliva, gastric juices, water, or other aqueous fluid, such that dissolution, softening, and / or swelling of the spacer 364 occurs, the electronic conductor 366 can be biased into electronic contact with the cathode can 314, thereby electronically coupling the cathode can 314 to the anode cup 318. As a result, the battery 300 is short-circuited, protecting the consumer during a safety condition, such as if the battery 300 were swallowed by a person or pet animal. In the illustrated embodiment, insulating gasket 362 is shown as a separate component from spacer 364 so that it can remain intact after battery 300 comes into contact with aqueous fluid, thereby maintaining the cathode 352 and anode 356 materials within battery 300. However, in other embodiments, insulating gasket 362 and spacer 364 can form a unitary structure, in which case spacer 364 also functions as insulating gasket 362, effectively providing insulating gasket 362, as noted with respect to spacer 64 and insulating gasket 62 above in connection with Figures 2A and 2B.

[0044] 7 illustrates a further exemplary battery 400 with a safety feature according to the present disclosure designed to protect against tissue damage and / or electrolysis. The battery 400 includes a cathode can 414 and an anode cup 418. A cathode 452 is disposed within the cathode can 414, and an anode 456 is disposed within the anode cup 418. The cathode 452 and the anode 456 are electronically separated by a separator 460 within the battery 400. The cathode can 414 and the anode cup 418 each form a different pole of the battery 400, with the cathode can 414 forming the positive pole and the anode cup 418 forming the negative pole. An insulating gasket 462 electronically insulates the cathode can 414 from the anode cup 418 and prevents any part of the anode cup 418 from contacting the cathode can 414, sealing the battery 400 and preventing electrolyte loss. Battery 400 shares many of the same elements as those shown in connection with battery 50 described above in FIGS. 2A and 2B, and therefore, generally only the differences will be described herein.

[0045] 7 , the battery 400 includes a first electronic conductor 466 in electronic contact with the cathode can 414 and a second electronic conductor 480 in electronic contact with the anode cup 418. A spacer 464 is disposed between the first electronic conductor 466 and the second electronic conductor 480. After the battery 400 is exposed to an aqueous solution or bodily fluid, upon dissolution, softening, and / or swelling of the electronically insulating material of the spacer 464, the second electronic conductor 480 can be biased toward engagement with the first electronic conductor 466 such that the second electronic conductor 480 can contact the first electronic conductor 466, thereby electronically coupling the cathode can 414 to the anode cup 418. As a result, the battery 400 is short-circuited, protecting the consumer during a safety condition, such as if the battery 400 is swallowed by a person or pet animal. In the illustrated embodiment, the cathode can 414 and the first electronic conductor are shown as separate components, but it should be understood that the electronic conductor 466 and the cathode can 414 may form a unitary structure such that the cathode can 414 itself also functions as the electronic conductor 466, effectively providing the electronic conductor 466. Thus, in this embodiment, a separate electronic conductor 466 is not required.

[0046] 8 illustrates a further exemplary battery 500 with a safety feature according to the present disclosure designed to protect against tissue damage and / or electrolysis. The battery 500 includes a cathode can 514 and an anode cup 518. A cathode 552 is disposed within the cathode can 514, and an anode 556 is disposed within the anode cup 518. The cathode 552 and the anode 556 are electronically separated by a separator 560 within the battery 500. The cathode can 514 and the anode cup 518 each form a different pole of the battery 500, with the cathode can 514 forming the positive pole and the anode cup 518 forming the negative pole. An insulating gasket 562 electronically insulates the cathode can 514 from the anode cup 518 and prevents any part of the anode cup 518 from contacting the cathode can 514, sealing the battery 500 and preventing electrolyte loss. Battery 500 shares many of the same elements as those shown in connection with battery 50 previously described in FIGS. 2A and 2B, and therefore, generally only the differences will be described herein.

[0047] As shown in FIG. 8 , the battery 500 includes a first spacer 564 and a second spacer 564′. The spacer 564 may comprise a discrete portion or a continuous peripheral layer around the cathode can 514. Similarly, the spacer 564′ may comprise a continuous layer or a discrete portion. The spacers 564, 564′ are disposed between the cathode can 514 and anode cup 518 (corresponding to the first and second battery poles) and an electronic conductor 566. After the battery 500 is exposed to an aqueous solution or bodily fluid, dissolution, softening, and / or swelling of the electronically insulating material of the spacers 564, 564′ can bias the electronic conductor 566 toward engagement with the cathode can 514 and anode cup 518, thereby electronically coupling the cathode can 514 and anode cup 518. As a result, the battery 500 is shorted and the consumer is protected during a safety condition, such as if the battery 500 is swallowed by a person or pet animal.

[0048] Throughout this specification, multiple instances may implement components or structures described as a single instance. Structures and functionality presented as separate components in the configuration examples may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements are within the scope of the subject matter herein.

[0049] As used herein, any reference to "one embodiment" or "an embodiment" means that a particular element, feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in this specification are not necessarily all referring to the same embodiment.

[0050] Some embodiments described herein use the terms "coupled" and / or "connected." For example, some embodiments are described using the terms "coupled" or "connected" to describe two or more elements that are in direct physical or electronic contact. However, the terms "coupled" and "connected" can also mean that two or more elements are not in direct physical contact with each other, but yet still cooperate or interact with each other. The embodiments are not limited in this regard.

[0051] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover non-exclusive inclusions. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements and may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or," not an exclusive "or." For example, element A or B may be satisfied by any one of the following: A is present and B is not present; A is absent and B is present; and both A and B are present.

[0052] Furthermore, the use of "a" or "an" is used to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the description. This description and the claims that follow should be read to include one or at least one, and the singular also includes the plural unless it is clear that it is meant otherwise.

[0053] This detailed description should be construed as merely exemplary and does not describe every conceivable embodiment, as describing every conceivable embodiment would be impractical, if not impossible. Numerous alternative embodiments can be implemented using either current technology or technology developed after the filing date of this application.

Claims

1. 1. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis, a housing including a cathode can and an anode cup, and a spacer including an electronically insulating material; the spacer is provided between the extension of the cathode can and the outer wall of the anode cup to prevent electrical contact between the cathode can and the anode cup; the spacer is capable of undergoing a physical change in the presence of an aqueous solution such that the spacer can dissolve, soften, or swell, such that the resistive force of the spacer becomes less than the biasing force of the extension, and electronic coupling between the extension and the anode cup can occur; following the physical change, electronic coupling occurs based on either (i) direct physical contact between the extension and the anode cup, or (ii) indirect physical contact between the extension and the anode cup via one or more additional intervening electronically conductive materials disposed between the extension and the anode cup; The battery, wherein the extension and the cathode can are of unitary construction, and the extension is biased in a direction to engage with the outer wall of the anode cup.

2. 10. The battery with safety features adapted to protect against tissue damage and / or electrolysis of claim 1, wherein the electronic conductor comprises a metal, a metal alloy, a conductive polymer, a conductive composite, or any combination thereof.

3. 3. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 2, wherein the electronically insulating material comprises at least one water-soluble material.

4. 4. The battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 3, wherein the electronically insulating material comprises a sugar, a polyether, polyacrylic acid (PAA), polyamide (PA), polyacrylate, polyvinyl alcohol, modified polyvinyl alcohol, acrylate copolymer, polyvinylpyrrolidone, pullulan, gelatin, carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), polyethylene oxide, polyethylene glycol, low viscosity grade hydroxypropyl cellulose, polysaccharides, natural polymers, modified starch, the foregoing copolymers, salts thereof, or any combination thereof.

5. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 4, wherein the spacer comprises at least one hydrogel.

6. The spacer is NaHPO ４ 6. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis as claimed in any one of claims 1 to 5, comprising sodium chloride (NaCl), potassium chloride (KCl), baking soda, sugar, sugar-like substances, citric acid, mixtures thereof, and any combination thereof.

7. 7. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 6, wherein the resistance of the electronic insulating material is greater than 0.5 megaohms, greater than 5 megaohms, or greater than 500 megaohms.

8. 8. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 7, wherein the spacer is positioned between the overhang of the extension and the anode cup.

9. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 8, wherein the extension comprises a protrusion.

10. 10. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis as claimed in any one of claims 1 to 9, wherein the extension comprises a bent portion biased towards engagement with the anode cup.

11. 11. The battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis of any one of claims 1 to 10, further comprising an insulating gasket 262 that electronically insulates the anode cup from the cathode can, the insulating gasket preventing any part of the anode cup from contacting the cathode can and sealing the battery to prevent electrolyte loss.

12. 11. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis as described in any one of claims 1 to 10, wherein the spacer further functions and effectively provides an insulating gasket, electronically isolating the cathode can from the anode cup and sealing the battery to prevent electrolyte loss.

13. 13. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis as described in any one of claims 1 to 12, wherein the insulating gasket and the spacer are of one integral structure, and the spacer also functions as and effectively provides the insulating gasket.

14. 14. A battery with a safety mechanism adapted to protect against tissue damage and / or electrolysis according to any one of claims 1 to 13, wherein the extension of the cathode can is formed as an extension of the side wall of the cathode can.

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