Aerosol-generating article comprising a capacitor

Abstract

An aerosol-generating article (1) will be described. The article (1) includes a capacitor (6) containing an electrolyte that generates an aerosol for inhalation by a user when heated.

Description

Technical Field

[0001] The present disclosure generally relates to aerosol generating articles, and more particularly to aerosol generating articles adapted to be received within an aerosol generating device for generating an aerosol for inhalation by a user.

[0002] The present disclosure is particularly applicable to portable (handheld) aerosol generating devices.

Background Art

[0003] In recent years, devices that heat rather than burn aerosol generating materials to generate an aerosol for inhalation have become popular among consumers. Commonly available risk reduction or risk modification devices are material heating type aerosol generating devices or so-called heat-not-burn devices. This type of device generates an aerosol or vapor by heating an aerosol generating material to a temperature typically in the range of 150°C to 300°C. This temperature range is considerably lower compared to conventional cigarettes. When the aerosol generating material is heated to a temperature within this range without burning or combusting the aerosol generating material, vapor is generated, and this vapor typically cools and condenses to form an aerosol for inhalation by the user of the device.

[0004] Such devices may supply heat to the aerosol generating material using one of several different techniques. All approaches for heating the aerosol generating material require a certain type of power source, such as a battery, which increases the size and weight of the device. Embodiments of the present disclosure seek to provide a power source in an aerosol generating article that may be used to supplement or partially replace the power source of the device. This may result in a smaller and lighter device that is beneficial to the user while maintaining precise control of the heating of the aerosol generating material and optimizing the characteristics of the generated aerosol.

Summary of the Invention

Means for Solving the Problems

[0005] According to a first aspect of the present disclosure, an aerosol-generating article including a capacitor is provided, the capacitor including an electrolyte that generates an aerosol for inhalation by a user when heated. The electrolyte is thus aerosolizable, i.e., can be converted into an aerosol by heating, and this aerosol is then inhaled by the user. Thus, by heating the capacitor, the electrolyte contained within the capacitor is converted into an aerosol, and the aerosolized electrolyte is then inhaled by the user.

[0006] The capacitor may have any suitable structure, but in a preferred embodiment is a supercapacitor such as an electric double layer supercapacitor. The capacitor may further include a pair of electrodes and a porous separator between the electrodes. The first electrode may be a positive electrode, the second electrode may be a negative electrode, or vice versa. The electrodes and separator are immersed in the electrolyte.

[0007] Similar to a conventional capacitor, in an electric double layer supercapacitor, charge is stored in the electric field between the electrodes, and the capacitance is a function of the surface area of the electrodes, the distance between the electrodes, and the dielectric constant of the separator material. The capacitor has a higher power density than conventional power sources such as batteries. When the capacitor is charged by an external circuit connected to the pair of electrodes, cations in the electrolyte move towards the negative electrode and anions move towards the positive electrode, while electrons move from the negative electrode to the positive electrode through the external circuit. Two charge layers (electric double layers) having opposite polarities are thus formed at the interfaces with the electrodes. When charging is complete, the positive charges on the positive electrode attract the anions in the electrolyte to stabilize the double layer on the electrode, while the negative charges on the negative electrode attract the cations in the electrolyte. A stable voltage is generated. When the capacitor is discharged, the reverse process occurs.

[0008] Each electrode may include at least one carbon-based electrode layer, for example, a layer of porous carbon material or activated carbon with a large specific surface area per volume and high compatibility with the proposed electrolyte.

[0009] Each electrode may further include a metal foil layer, for example, a current collector, and the current collector may include an aluminum foil layer. The carbon-based electrode layer may be positioned adjacent to one or both sides of the current collector. Each carbon-based electrode layer may be formed as a coating. Such electrodes may be manufactured relatively easily and inexpensively using materials that are already known to be used in aerosol generating articles.

[0010] As will be understood by those skilled in the art, the electrolyte serves two functions. First, it enables the movement of cations and anions that occur when the capacitor is charged or discharged, and second, when heated, it forms an aerosol that is safe for inhalation by the user and has good properties. Therefore, the electrolyte should be selected accordingly. The electrolyte is preferably a food-grade electrolyte and may include, for example, one or more of sodium chloride, sodium citrate, sodium bicarbonate, potassium chloride, calcium lactate, calcium carbonate, tricalcium phosphate, magnesium citrate, magnesium carbonate, citric acid, tartaric acid, benzoic acid, glycerol, and any suitable equivalents. The electrolyte may optionally include a gelling agent such as, for example, polyvinyl alcohol, gellan gum, or xanthan gum. In one embodiment, the electrolyte may include sodium chloride and glycerol, and optionally polyvinyl alcohol as a gelling agent. Such an electrolyte has been found to enable the movement of cations and anions and is also safe for inhalation by the user.

[0011] If all the electrolyte has evaporated, the capacitor may no longer be discharged or charged, and the article may need to be properly discarded or refilled with electrolyte.

[0012] The separator must provide dielectric separation between a pair of oppositely charged electrodes. The separator must also store an electrolyte within its pores and allow the passage of cations and anions during the charge and discharge process. The separator may comprise any suitable material. The separator may comprise a plant-derived material, particularly, it may comprise a tobacco material, for example, a porous tobacco sheet, or any suitable cellulose or polypropylene-based material. When heated, the separator material may release one or more volatile compounds. The volatile compounds may include flavor compounds such as nicotine or tobacco or other fragrances.

[0013] The aerosol-generating article may further comprise any type of solid or semi-solid material downstream of the capacitor within the aerosol flow path. Exemplary types of solid or semi-solid materials include chunks, powders, granules, pellets, flakes, strands, particles, gels, strips, loose leaf, cut filler, porous materials, foamed materials, or sheets. The material may comprise a plant-derived material, particularly a tobacco material. The aerosol generated by heating the electrolyte of the capacitor may flow through a solid or semi-solid material positioned between the capacitor and, for example, a filter segment or mouthpiece through which the user inhales the aerosol. The solid or semi-solid material may release one or more volatile compounds that may, for example, add flavor and nicotine to the aerosol. Any heating provided by the capacitor may also heat or warm the solid or semi-solid material and promote the release of volatile compounds.

[0014] The aerosol inhaled by the user essentially consists of vaporized or aerosolized electrolyte and optionally one or more volatile compounds that may be released by the separator material and / or the downstream solid or semi-solid material.

[0015] The capacitor may have any suitable structure, such as a substantially cylindrical or flattened spiral wound (or "jelly roll") structure, a prismatic structure, a folded or accordion structure, or a stacked structure, which may be more suitable for a flat-form article, for example, and may have a more cuboid shape.

[0016] In one embodiment, the layered capacitor substrate may include a first electrode, a separator adjacent to the first electrode, and a second electrode adjacent to the separator, i.e., the separator may be included so as to be sandwiched between the first and second electrodes, particularly between a pair of carbon-based electrode layers. The first electrode may be the positive electrode, the second electrode may be the negative electrode, or vice versa. Such a substrate may be wound or folded into a suitable shape while maintaining an air gap or other dielectric separation between opposing electrodes or different portions of the same electrode. In addition to that provided by the separator, the dielectric separation may be provided, for example, by one or more layers of a dielectric material. The dielectric material may include any suitable material. The dielectric material may include plant-derived materials, particularly tobacco materials, such as a porous tobacco sheet, or may include any suitable cellulose or polypropylene-based material. When heated, the dielectric material may release one or more volatile compounds. The volatile compounds may include flavor compounds such as nicotine or tobacco or other fragrances. The dielectric material and the separator material may be the same or different.

[0017] In another embodiment, the layered capacitor substrate may include a first electrode, a first separator adjacent to the first electrode, and a second electrode adjacent to the first separator, i.e., the first separator may be sandwiched between the first and second electrodes, particularly between a pair of carbon-based electrode layers, and the second separator may be adjacent to the second electrode. The second electrode is sandwiched between the first and second separators. The first electrode may be the positive electrode, the second electrode may be the negative electrode, or vice versa. Such a substrate may be substantially cylindrical or particularly suitable for a spiral wound (or "jelly roll") structure that can be flattened to have a more rectangular shape. Dielectric separation between the windings of a spiral wound capacitor may be provided by a second separator that may be sandwiched between the first and second electrodes, particularly between a pair of carbon-based electrode layers, in the wound substrate.

[0018] In yet another arrangement, the layered capacitor substrate may include a plurality of first electrodes, a plurality of second electrodes, and a plurality of separators. The first electrode may be the positive electrode, the second electrode may be the negative electrode, or vice versa. The first and second electrodes are alternately laminated such that the substrate includes the first electrode, the second electrode, the first electrode, the second electrode, etc. in the lamination direction. The separator is sandwiched between each pair of electrodes, particularly between a pair of carbon-based electrode layers, to provide dielectric separation. Such a substrate may be useful for flat-form articles. The first electrodes may be electrically connected to each other, and the second electrodes may be electrically connected to each other. The first electrode may be electrically connected to a first capacitor terminal, and the second electrode may be electrically connected to a second capacitor terminal.

[0019] The capacitor may be housed inside a casing. In particular, the casing may house a capacitor substrate including electrodes, separators, etc., and an electrolyte. The electrolyte may be injected into the casing during manufacturing or when the capacitor needs to be refilled. The casing may electrically insulate the capacitor and may be formed from any suitable single or plural materials.

[0020] The casing may include, for example, a paper wrapper having a metal or polymer coating. The casing may include a pair of end caps of any suitable material. The casing may include suitable perforations or openings, or may incorporate a suitable aerosol-permeable membrane material such that aerosols generated when the electrolyte is heated may be freely inhaled by the user while also preventing leakage of the electrolyte when in a liquid or gel state. The aerosol-generating article may include a filter segment at its proximal end, the filter segment including, for example, cellulose acetate fibers. The filter segment may constitute a mouthpiece filter. In some designs, one or more vapor collection regions, cooling regions, and other structures may also be included. The vapor cooling region may advantageously enable the vapor to cool and condense to form an aerosol having suitable properties for inhalation by the user, for example, through the filter segment. Generally speaking, a vapor is a substance that is in the gas phase at a temperature below its critical temperature, which means that the vapor may be condensed to a liquid by increasing the pressure without decreasing the temperature, while an aerosol is one in which fine solid particles or droplets are suspended in air or another gas. However, it should be noted that in this specification, the terms "aerosol" and "vapor" may be used interchangeably without distinction.

[0021] The capacitor is preferably pre-charged within the packaged article, i.e., the capacitor is already charged when purchased by the user and before being removably inserted into the aerosol-generating device. Pre-charging the capacitor reduces the amount of energy required from the device's power source for heating. This may lead to miniaturization and weight reduction of the device.

[0022] According to a second aspect of the present disclosure, there is provided an aerosol generating device adapted to receive an aerosol generating article as described above in use. The device may include an external circuit (e.g., a switching circuit) that is electrically connected between a pair of electrodes or capacitor terminals when the article is received within the device. The switching circuit may be configured to control the discharge of the capacitor. The switching circuit may also optionally be configured to control the charging of the capacitor from a power source of the device, such as a battery. The switching circuit may include a switching device controlled by a controller to selectively provide a continuous or switched (i.e., discontinuous or intermittent) short-circuit path between a pair of electrodes or capacitor terminals that enables the charge accumulated in the capacitor to be discharged through the switching circuit. The switching device may include one or more switches. The one or more switches may be, for example, semiconductor switching devices that may be connected as a bridge circuit or a converter circuit. The one or more switches may be opened and closed or switched on and off by the controller to provide a short-circuit path.

[0023] The switching circuit may include a first terminal electrically connected to the first electrode or terminal of the capacitor and a second terminal electrically connected to the second electrode or terminal of the capacitor when the aerosol-generating article is received within the device. Prior to insertion of the article into the device, at least one of the electrodes or terminals of the capacitor is preferably inaccessible to the user to prevent accidental or intentional discharge of the pre-charged capacitor. For example, one or both of the capacitor electrodes or terminals may be concealed within the casing of the article and be made accessible for electrical connection to the terminals of the switching circuit only after or during the process of insertion of the aerosol-generating article into the device. The electrical connection may require the casing to be broken at one or more locations, and the device may include suitable means for breaking, piercing, or tearing the casing. The first terminal of the switching circuit may be electrically directly connected to the first electrode at one or more locations or may be electrically connected to a first capacitor terminal that is electrically connected in sequence to the first electrode. Similarly, the second terminal of the switching circuit may be electrically directly connected to the second electrode at one or more locations or may be electrically connected to a second capacitor terminal that is electrically connected in sequence to the second electrode. The capacitor terminals may be located anywhere on the article, for example, near the end cap or side of the article. The orientation of insertion of the aerosol-generating article into the device may be restricted to ensure accurate alignment between the respective terminals so as to provide a reliable electrical connection between the capacitor and the external switching circuit.

[0024] The terminals of the switching circuit may be formed as a breaking device designed to break, pierce, or tear the casing to electrically connect to the electrodes or terminals of the capacitor. The breaking device may be fixed or stationary to the device and may be designed to break, pierce, or tear the casing when an article is inserted into the device, for example, into an aerosol generating space or a heating chamber. The breaking device may also be movable. For example, in one arrangement, the breaking device may be attached to a panel or door of the device that opens or is removed to allow insertion of the article, and the breaking device may be designed to break, pierce, or tear the casing when the panel or door is closed by the user. The panel or door may be, for example, hinge-type. In another arrangement, the breaking device may be moved, for example, by a suitable actuator such as an electric motor or piston. The breaking device may be moved through an opening or slot in a part of the device that defines the aerosol generating space or the heating chamber. The breaking device may have any suitable shape and may be formed, for example, as a needle-type or crown-type having one or more pointed ends, a blade-type having an edge, or a punch-type having a non-pointed end. The breaking device may be designed to operate with any of the capacitor structures described above. If one of the electrodes or terminals of the capacitor is accessible, only one breaking device may be required.

[0025] According to a third aspect of the present disclosure, there is provided a method of controlling an aerosol generating system comprising an aerosol generating device and an aerosol generating article as described above. The method includes discharging a capacitor to heat an electrolyte, thereby generating an aerosol for inhalation by a user. Discharging a capacitor pre-charged via an external circuit such as a switching circuit of the device generates heat in the electrodes, which in turn heats the electrolyte in which the electrodes are immersed. Sufficient heating of the electrolyte generates an aerosol inhaled by the user during a vaping session. To provide improved heating, the internal resistance of the capacitor may be increased by increasing the thickness of the separator between the oppositely charged electrodes. This may result in a capacitor having fewer windings or folds if the overall dimensions are the same. Using an external circuit to charge the capacitor also generates heat within the electrodes, which in turn heats the electrolyte to generate the inhaled aerosol.

[0026] The discharge of the capacitor and any charging, and thus the heating of the electrolyte, may be controlled using a switching circuit which may be part of the aerosol generating device. The device may also include an external heater for heating the capacitor to generate an aerosol for inhalation by the user. In other words, the heating of the electrolyte is not limited to the heat generated by the capacitor when the capacitor is discharged or charged, but the capacitor may be heated by an external heater in a similar manner to conventional aerosol generating materials or substrates. Such heating still heats the electrolyte to generate the inhaled aerosol. By using an external heater, more controllable heating may be provided during certain phases of the vaping session, thereby optimizing the user experience. Any suitable heater, for example, a low power thin film heater, a printed heater, etc. may be used. The heat generated by discharging the capacitor may be used during an initial preheating phase, and the external heater may be used, for example, to heat the electrolyte to generate an aerosol during a subsequent heating or vaping phase. The power for preheating may thus be provided at least in part by the capacitor rather than by the power source of the device. This enables miniaturization of the power source and thus the device can be made smaller and lighter. Alternatively, the electrolyte may be heated during a subsequent heating or vaping phase by repeated charging and discharging of the capacitor. There may be times during the heating or vaping phase when heating is not required and thus the capacitor need not be discharged or charged. When heating is required, the capacitor may be continuously discharged or charged or may be intermittently discharged or charged, for example, using a suitable duty cycle. In this alternative embodiment, the external heater may be used to heat the electrolyte during an initial preheating phase. The preheating phase may generally be intended to preheat the electrolyte to a target temperature, and the heating or vaping phase may generally be intended to heat the electrolyte over a longer period while the aerosol is being generated.When an external heater is not required, heating may be provided entirely by the capacitor, which may reduce the cost of the device and may simplify the overall design.

[0027] If all heating could be provided by the capacitor, the aerosol-generating article may be formed as a single-use or disposable device that does not need to be inserted into another device. In other words, the aerosol-generating article may include an external circuit, such as a switching circuit, for controlling the discharge of the capacitor, and any other components necessary for a properly functioning single-use or disposable device.

Brief Description of the Drawings

[0028]

Figure 1

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Figure 4

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Figure 10

Modes for Carrying Out the Invention

[0029] Here, by way of mere example and with reference to the accompanying drawings, embodiments of the present disclosure will be described.

[0030] Referring initially to FIG. 1, a schematic illustration of an embodiment of an aerosol generating system 1 is shown. The article 1 has a proximal end 2 and a distal end 4.

[0031] The article 1 includes a capacitor 6 containing an electrolyte. The capacitor 6 is surrounded by a paper wrapper 8 having a metal or polymer coating. End caps 10a, 10b are provided at each end of the capacitor 6. The paper wrapper 8 and the end caps 10a, 10b define an outer casing for the capacitor 6 that contains the electrolyte and provides electrical insulation.

[0032] The article 1 is generally cylindrical.

[0033] At the proximal end 2, the article 1 includes a mouthpiece 12 having an outlet 14 through which a user may inhale an aerosol generated by heating the electrolyte. Although not shown, the proximal end cap 10a may include suitable perforations or openings or incorporate a suitable aerosol-permeable membrane material so that the generated aerosol may pass through the end cap to the outlet 14.

[0034] Referring to FIG. 2, the capacitor 6 is an electric double layer supercapacitor and has a spiral wound (or "jelly roll") structure. The capacitor 6 is generally cylindrical so as to fit conveniently within the article 1. However, a capacitor having the same spiral wound structure may be flattened to have a more rectangular shape that may be suitable for flat-form aerosol generating articles.

[0035] The capacitor 6 includes a positive electrode 16 and a negative electrode 18. The electrodes 16, 18 are separated by a pair of porous separators 20a, 20b. As shown more clearly in FIG. 3, the positive electrode 16 includes a positive current collector 22. On each side of the positive current collector 22, a porous carbon-based electrode layer 24 such as a layer of porous carbon material or activated carbon is provided, for example. The negative electrode 18 includes a negative current collector 26. On each side of the negative current collector 24, a porous carbon-based electrode layer 28 such as a layer of porous carbon material or activated carbon is provided, for example. The positive and negative current collectors 22, 26 are, for example, aluminum foil layers.

[0036] The separators 20a, 20b are formed from a tobacco material such as a porous tobacco sheet that releases volatile compounds when heated.

[0037] The electrodes 16, 18 and the separators 20a, 20b are immersed in an electrolyte that allows the movement of cations and anions when the capacitor 6 is charged or discharged and generates an aerosol for inhalation by the user when heated. The electrolyte may include sodium chloride and glycerol, and optionally polyvinyl alcohol as a gelling agent. However, other food-grade electrolytes may be used. The capacitor 6 is pre-charged during the manufacturing process, packaged in a pre-charged state, and sold to the user.

[0038] The article 1 includes a positive capacitor terminal 30 that is electrically connected to the positive electrode 16, i.e., the positive current collector 22, at one or more locations, and a negative capacitor terminal 32 that is electrically connected to the negative electrode 18, i.e., the negative current collector 26, at one or more locations. The capacitor terminals 30, 32 may be installed inside the outer casing of the article 1 so that they are not accessible to the user. This helps to prevent accidental or intentional discharge of the capacitor 6 before the article is removably inserted into an aerosol generating device in preparation for the start of a vaping session.

[0039] FIG. 4 shows an aerosol generating device 34 that is adapted to receive the aerosol generating article 1. The device 34 includes a cavity 36 into which the article 1 may be inserted.

[0040] Device 34 includes a pair of breaking devices 38, 40 adapted to break its distal end cap 10b when article 1 is inserted into cavity 36. The angular orientation of article 1 relative to device 34 may be limited such that when it is inserted into cavity 36, breaking device 38 is electrically connected to positive electrode 30 and breaking device 40 is electrically connected to negative electrode 32. Other methods may be used to ensure a reliable electrical connection. For example, the positive and negative terminals of the article may have an annular structure and be coaxially installed with respect to each other such that appropriately positioned breaking devices make electrical contact with the terminals regardless of the angular orientation of the article relative to the device.

[0041] Device 34 includes a switching circuit 42 and a power source 44 such as a battery.

[0042] An example of switching circuit 42 is shown in FIG. 5. Switching circuit 42 includes breaking devices 38, 40 that function as positive and negative terminals and are electrically connected to positive and negative terminals 30, 32 of article 1 when article 1 is properly received within cavity 36. Switching circuit 42 includes a switching device 46 that may be operated by a controller 48 to control the discharge of capacitor 6 through switching circuit 42. Controller 48 may include, for example, at least one microcontroller unit (MCU) or microprocessor unit (MPU).

[0043] After article 1 is inserted into device 34, capacitor 6 may be discharged by controlling switching device 46 to provide a continuous or switched short - circuit path between the positive and negative terminals 30, 32 of article 1 and thus between the positive and negative electrodes 16, 18 of capacitor 6. The short - circuit path between the positive and negative terminals 30, 32 is formed via the switched device 46. Additionally, the switching device 46 may include a resistor to prevent over - discharge current or an electrical load to enable constant - current discharge. By discharging capacitor 6 via switching circuit 42, the heat in electrodes 16, 18 is dissipated. This heats the electrolyte and generates an aerosol that may be inhaled by the user through outlet 14 in mouthpiece 12. By pre - charging capacitor 6, the amount of energy required from the device's power source 44 for heating is reduced. This may lead to an overall miniaturization and weight reduction of device 34. In particular, it is possible to reduce the size and weight of power source 44. This is important because often the power source is the largest and heaviest component of device 34. In some cases, the energy for heating may be provided entirely by capacitor 6 and power source 44 may be removed or reduced to provide power to other components of the device, such as a controller. However, in other cases, the energy provided by capacitor 6 is used to supplement or partially replace the energy provided by power source 44.

[0044] Capacitor 6 may also be charged from power source 44 by controlling switching device 46 (or a separate switching device of a switching circuit not shown). By charging capacitor 6, heat in electrodes 16, 18 is also dissipated, which heats the electrolyte and generates an aerosol that may be inhaled by the user through outlet 14 in mouthpiece 12. Thus, repeatedly charging capacitor 6 from power source 44 and then discharging the capacitor via switching circuit 42 may generate heat.

[0045] The switching device 46 that can be used to enable the above-described charging and discharging of the capacitor 6 may include, for example, one or more switches. The discharge switch for controlling the discharge current of the capacitor 6 may be connected in series between the breaking devices 38 and 40 that define the positive and negative terminals of the switching circuit 42. The charging switch for controlling the charging current of the capacitor 6 may be connected in series between the breaking device 38 that defines the positive terminal of the switching circuit 42 and the positive terminal of the power source 44, and / or in series between the breaking device 40 that defines the negative terminal of the switching circuit 42 and the negative terminal of the power source. The switch may be a semiconductor switching device, for example, a transistor.

[0046] Although not shown, the device 34 may include a current sensor that measures the discharge or charging current of the capacitor 6 and a voltage sensor that measures the voltage output of the capacitor. The measurement values provided by the current sensor and the voltage sensor may be used, for example, to identify one or more electrical parameters of the capacitor, such as the internal resistance or capacitance, for monitoring or operating purposes.

[0047] The device 32 may optionally include one or more heaters 50. The heater 50 may be used to heat the electrolyte in the capacitor 6 to generate an aerosol that may be inhaled by the user through the outlet 14 in the mouthpiece 12. Such heating may be used, for example, to better control the heating of the electrolyte during the heating or vaping phase.

[0048] FIG. 6 shows an alternative capacitor 52 having a folded or pleated structure. A capacitor having this particular configuration may be suitable for flat-form aerosol-generating articles. Capacitor 52 includes a positive electrode 54 and a negative electrode 56. Electrodes 54, 56 are separated by a separator 58a formed from a tobacco material such as a porous tobacco sheet that releases a volatile compound when heated. As more clearly shown in FIG. 7, positive electrode 54 includes a positive current collector 60. A porous carbon-based electrode layer 62, such as a layer of porous carbon material or activated carbon, is provided on the side of positive current collector 60 facing separator 58a. Negative electrode 56 includes a negative current collector 64. A porous carbon-based electrode layer 66, such as a layer of porous carbon material or activated carbon, is provided on the side of negative current collector 64 facing separator 58a. Positive and negative current collectors 60, 64 are, for example, aluminum foil layers. A first dielectric layer 58b is provided on the other side of positive current collector 60, and a second dielectric layer 58c is provided on the other side of negative current collector 64. Dielectric layers 58b, 58c provide dielectric separation between the folds of capacitor 52, i.e., where the positive and negative electrodes 54, 56 overlap themselves. (In FIG. 6, the folds are spaced apart for clarity, but it will be understood that in practice, the opposing portions of dielectric layers 58b, 58c may be in direct contact.) Dielectric layers 58b, 58c are formed from a tobacco material such as a porous tobacco sheet that releases a volatile compound when heated, but an air gap or other suitable dielectric material may be used if appropriate. Dielectric layers 58b, 58c are thus substantially the same as separator 58a, and these are also immersed in the electrolyte.

[0049] FIG. 8 shows an alternative capacitor 68 having a laminated structure. A capacitor having this particular configuration may be suitable for flat-form aerosol-generating articles. Capacitor 68 includes a plurality of positive electrodes 70, a plurality of negative electrodes 72, and a plurality of separators 74 formed from a tobacco material such as a porous tobacco sheet that releases a volatile compound when heated. The positive and negative electrodes 70, 72 are alternately arranged in the lamination direction. Each positive electrode 70 includes a tab 70a, and each negative electrode 72 includes a tab 72a. Although not shown, the tab 70a of the positive electrode 70 is electrically connected to the positive capacitor terminal. The tab 72a of the negative electrode 72 is electrically connected to the negative capacitor terminal. As shown more clearly in FIG. 9, each positive electrode 70 includes a positive current collector 76. On both sides of the positive current collector 76, porous carbon-based electrode layers 78 such as layers of porous carbon material or activated carbon are provided, for example. Each negative electrode 72 includes a negative current collector 80. On both sides of the negative current collector 80, porous carbon-based electrode layers 82 such as layers of porous carbon material or activated carbon are provided, for example. The positive and negative current collectors 76, 80 are, for example, aluminum foil layers.

[0050] FIG. 10 shows an alternative aerosol-generating article 84 similar to the aerosol-generating article described above, and like parts are given the same reference numerals. Article 84 includes a capacitor 86. The separator of capacitor 86 is a cellulose or polypropylene-based material instead of being formed from a tobacco material. However, the separator can also be formed from a tobacco material such as a porous tobacco sheet if appropriate. Article 84 includes a tobacco material 88 such as crimped tobacco. The tobacco material 88 is downstream of the capacitor 86 in the aerosol flow path indicated by the arrow in FIG. 10. The aerosol generated by heating the electrolyte of the capacitor 86 flows through the tobacco material 88 positioned between the capacitor 86 and the mouthpiece 12. The tobacco material 88 adds flavor and nicotine to the aerosol. The heating provided by the capacitor 86 also heats or warms the tobacco material 88, which promotes the release of volatile compounds. Instead of the tobacco material, a nicotine-free flavor source may be used.

[0051] Although the exemplary embodiments have been described in the previous paragraphs, it goes without saying that various modifications may be made to those embodiments without departing from the scope of the appended claims. Therefore, the breadth and scope of the claims should not be limited to the exemplary embodiments described above.

[0052] Unless otherwise specified herein or clearly inconsistent with the context, any combination of the features described above in all possible variations is encompassed by the present disclosure.

[0053] Throughout this specification and the claims, unless the context clearly requires otherwise, words such as "comprise", "comprising", etc. shall be construed in an inclusive sense, i.e., in the sense of "including, but not limited to", rather than in an exclusive or exhaustive sense.

Claims

1. Aerosol generating article (1;84) comprising a capacitor (6;52;68;86), wherein the capacitor (6;52;68;86) comprises an electrolyte that, when heated, generates an aerosol for inhalation by the user.

2. The aerosol generating article according to claim 1 (1; 84), wherein the electrolyte comprises one or more of the following: sodium chloride, sodium citrate, sodium bicarbonate, potassium chloride, calcium lactate, calcium carbonate, tricalcium phosphate, magnesium citrate, magnesium carbonate, citric acid, tartaric acid, benzoic acid, glycerol, and any suitable equivalents thereof.

3. The aerosol generating article according to claim 1 (1; 84), wherein the electrolyte comprises a gelling agent.

4. The aerosol generating article according to claim 3 (1; 84), wherein the gelling agent comprises one or more of polyvinyl alcohol, gellan gum, and xanthan gum.

5. The aerosol generating article according to claim 1 (1; 84), wherein the electrolyte comprises sodium chloride and glycerol, and optionally polyvinyl alcohol.

6. The aerosol generating article (1; 84) according to claim 1, wherein the capacitor (6; 52; 68; 86) further comprises a pair of electrodes (16, 18; 54, 56; 70, 72), each electrode comprising at least one carbon-based electrode layer (24, 28; 62, 66; 78, 82).

7. Each electrode (16, 18; 54, 56; 70, 72) further comprises a current collector (22, 26; 60, 64; 76, 80), as described in claim 6 (1; 84).

8. The aerosol generating article (1; 84) according to claim 6, wherein the capacitor (6; 52; 68; 86) further includes porous separators (20a, 20b; 58a; 74) between the electrodes (16, 18; 54, 56; 70, 72).

9. The aerosol generating article (1) according to claim 8, wherein the porous separator (20a, 20b; 58a; 74) contains tobacco material.

10. The aerosol generating article (84) according to claim 8, wherein the porous separator comprises a cellulose or polypropylene-based material.

11. Furthermore, the aerosol generating article (84) according to claim 1 further includes tobacco material (88) downstream of the condenser (86) in the aerosol flow path.

12. The aerosol generating article (1; 84) according to claim 1, wherein the capacitor (6; 52; 68; 86) has one of a helical winding structure, a prismatic structure, a folded or zigzag structure, and a laminated structure.

13. The aerosol generating article according to claim 1 (1; 84), further comprising a mouthpiece from which the aerosol is inhaled by the user.

14. The aerosol generating article (1; 84) according to claim 1, wherein the capacitor (6; 52; 68; 86) is pre-charged within the packaged article.

15. Aerosol generating device (34) adapted to receive an aerosol generating article (1;84) according to any one of claims 1 to 14 when in use, further comprising a switching circuit (42) electrically connected between a pair of electrodes (16, 18, 54, 56, 70, 72) of the capacitor (6;52;68;86) and configured to control the discharge of the capacitor (6;52;68;86) and optionally the charging of the capacitor (6;52;68;86) from a power source (44) of the device (34).

16. A method for controlling an aerosol generating system comprising an aerosol generating device (34) and an aerosol generating article (1; 84) according to any one of claims 1 to 14, the method comprising discharging a capacitor (6; 52; 68; 86) to heat an electrolyte, thereby generating an aerosol for inhalation by a user.

17. The method according to claim 16, further comprising charging the capacitor (6; 52; 68; 86) to heat the electrolyte, thereby generating an aerosol for inhalation by the user.

18. The method according to claim 16, wherein the aerosol generating device (34) further comprises a heater (50), and the method comprises using the heater (50) to heat the electrolyte, thereby generating an aerosol for inhalation by a user.

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