Method for Heating an Aerosol Generating Article Containing an Electrolytic Capacitor

Abstract

A method of heating an aerosol-generating article (1) is described. The article (1) includes a capacitor (6) having an electrolyte. The method includes heating the electrolyte by performing at least one of discharging and charging the capacitor (6), thereby generating an aerosol for inhalation by a user.

Description

Technical Field

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

[0002] As part of an aerosol-generating system of the present disclosure, the aerosol-generating article may be received within an aerosol-generating device that includes a controller adapted to implement the method. 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 aerosol-generating devices or so-called heat-not-burn devices. This type of device generates an aerosol or vapor by heating the aerosol-generating material to a temperature typically in the range of 150°C to 300°C. This temperature range is significantly lower compared to conventional cigarettes. Heating the aerosol-generating material to a temperature within this range without burning or combusting the aerosol-generating material generates a vapor that typically cools and condenses to form an aerosol for inhalation by the user of the device.

[0004] Such a device can supply heat to the aerosol - generating material using one of several different techniques. All methods for heating the aerosol - generating material require a certain 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 the aerosol - generating article that can supplement or partially replace the power source of the device. This can, as a result, 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, a method of heating an aerosol - generating article including a capacitor is provided, the capacitor including an electrolyte that, when heated, generates an aerosol for inhalation by a user. 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, when the capacitor is heated, as a result, the electrolyte contained within the capacitor is converted into an aerosol, and the aerosolized electrolyte is then inhaled by the user. The method includes performing at least one of discharging and charging the capacitor to heat the electrolyte and thereby generate an aerosol for inhalation by the user.

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

[0007] Similar to conventional capacitors, in an electric double layer supercapacitor, charges are 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. Capacitors have a higher power density than conventional power sources such as batteries. When a capacitor is charged by an external circuit connected to a pair of electrodes, cations in the electrolyte move toward the negative electrode, anions move toward the positive electrode, while electrons move from the negative electrode to the positive electrode through the external circuit. Two charge layers (electric double layers) with opposite polarities are thus formed at the interfaces with the electrodes. When charging is complete, the positive charges on the positive electrode and the anions in the electrolyte attract each other to stabilize the double layer on the positive electrode, while the negative charges on the negative electrode and the cations in the electrolyte attract each other. 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 current collector, for example, 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 can be manufactured relatively easily and inexpensively using materials 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 occurs when the capacitor is charged or discharged. Second, when heated, it forms an aerosol that is safe for the user to inhale 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 example, 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 of the electrolyte has evaporated, the capacitor may no longer be charged or discharged, and the article may need to be properly discarded or refilled with electrolyte.

[0012] The separator must provide dielectric separation between pairs of oppositely charged electrodes. The separator stores the electrolyte within its pores and also enables the passage of cations and anions during the charging and discharging processes. The separator may include any suitable material. The separator 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 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 include any type of solid or semi-solid material downstream of the capacitor in the aerosol flow path. Exemplary types of solid or semi-solid materials include crumbs, powders, granules, pellets, flakes, strands, particles, gels, strips, loose leaf, cut filler, porous materials, foamed materials or sheets. The materials may include plant-derived materials and in particular may include tobacco materials. 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 can, 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 consists essentially of the 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 pleated structure or a laminated structure, which may be more suitable, for example, for an article in a flat form and having 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 is sandwiched between the first and second electrodes, particularly between pairs of carbon-based electrode layers. The first electrode may be the positive electrode, and the second electrode may be the negative electrode or vice versa. Such a substrate can be wound or folded into a suitable shape while maintaining a void or other dielectric separation between opposing electrodes or different portions of the same electrode. In addition to what is provided by the separator, the dielectric separation can be provided, for example, by one or more layers of a dielectric material. The dielectric material can include any suitable material. The dielectric material can include plant-derived materials, particularly tobacco materials such as porous tobacco sheets, or can include any suitable cellulose or polypropylene-based material. When heated, the dielectric material can release one or more volatile compounds. The volatile compounds can include nicotine or flavor compounds such as tobacco or other fragrances. The dielectric material and the separator material can 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 is sandwiched between the first and second electrodes, particularly between pairs of carbon-based electrode layers, and a second separator is adjacent to the second electrode. The second electrode is sandwiched between the first and second separators. The first electrode may be the positive electrode, and the second electrode may be the negative electrode or vice versa. Such a substrate is particularly suitable for a helical winding (or "jelly roll") structure that can be substantially cylindrical or flattened to have a more rectangular shape. The dielectric separation between the windings of the helical wound capacitor is provided by a second separator that can be sandwiched between the first and second electrodes, particularly between pairs of carbon-based electrode layers, in the wound substrate.

[0018] In yet another embodiment, the layered capacitor substrate can include a plurality of first electrodes, a plurality of second electrodes, and a plurality of separators. The first electrode can be the positive electrode, and the second electrode can 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 stacking direction. The separator is sandwiched between each pair of electrodes, particularly between pairs of carbon-based electrode layers, to provide dielectric separation. Such a substrate can be useful for flat-form articles. The first electrodes can be electrically connected to each other, and the second electrodes can be electrically connected to each other. The first electrode can be electrically connected to the first capacitor terminal, and the second electrode can be electrically connected to the second capacitor terminal.

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

[0020] The casing can include, for example, a paper wrapper having a metal or polymer coating. The casing can include a pair of end caps of any suitable material. The casing can include suitable perforations or openings, or can incorporate a suitable aerosol-permeable membrane material, such that aerosols generated when the electrolyte is heated can be freely inhaled by the user, while also preventing leakage of the electrolyte when in liquid or gel form. The aerosol-generating article can include, at the proximal end of the aerosol-generating article, a filter segment including, for example, cellulose acetate fibers. The filter segment can constitute a mouthpiece filter. In some designs, one or more vapor collection regions, cooling regions, and other structures can also be included. The vapor cooling region can 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 can be condensed into 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" can be used interchangeably.

[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. By pre-charging the capacitor, the amount of energy required from the device's power source for heating is reduced. This can lead to miniaturization and weight reduction of the device.

[0022] An aerosol generating device may be 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 optionally also be configured to control the charging of the capacitor from a power source of the device such as a battery. By controlling the discharge and charging of the capacitor, the heating of the electrolyte is controlled. The switching circuit may include a switching device that is 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 allows 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 semiconductor switching devices that are connected, for example, as a bridge circuit or a converter circuit. The one or more switches may be opened and closed or switched between 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 the article being inserted 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 the aerosol-generating article being inserted 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 series 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 series 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 to provide a reliable electrical connection between the capacitor and the external switching circuit.

[0024] The terminals of the switching circuit can be formed as a breaking device designed to break, pierce or tear the casing to make electrical connection with the electrodes or terminals of the capacitor. The breaking device can be fixed to or stationary with respect to the device and can 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 can also be movable. For example, in one arrangement, the breaking device can 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 is designed to break, pierce or tear the casing when the panel or door is closed by the user. The panel or door can be, for example, hinge-type. In another arrangement, the breaking device can be moved, for example, by a suitable actuator such as an electric motor or a piston that can push through the breaking device into the casing to make electrical connection. The breaking device can 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 can have any suitable shape and can 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 can 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] By discharging a capacitor pre-charged through an external circuit such as a switching circuit of a device, heat is generated in the electrodes, which thus 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 can be increased by increasing the thickness of the separator between oppositely charged electrodes. This can, as a result, result in a capacitor having fewer windings or folds when the overall dimensions are the same. Using an external circuit to charge the capacitor also generates heat in the electrodes, which thus heats the electrolyte to generate an inhaled aerosol.

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

[0027] When all heating can be provided by the capacitor, the aerosol generating article can 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 can include an external circuit for controlling the discharge of the capacitor, such as a switching circuit and any other components necessary for a properly functioning single-use or disposable device.

[0028] Optionally, discharging the capacitor can provide sufficient heating without the need to charge the capacitor. For example, the capacitor can be discharged continuously or intermittently through a switching circuit so as to provide sufficient heating of the electrolyte, at least during a preheating phase. Thereafter, the heating can be provided by an external heater. The method can also include circulating the capacitor between discharging and charging. By repeatedly circulating the capacitor between discharging and charging, continuous heating of the capacitor can be provided over a particular phase of the vaping session without the need for an external heater.

[0029] The capacitor can be discharged and / or charged between a predetermined upper limit and a lower limit. For example, expressed in terms of state of charge (SOC), the upper limit can be about 50 - 80% and the lower limit can be about 20 - 40%. SOC is defined here as the available capacity of the capacitor (in Ah units) and is expressed as a percentage of its rated capacity. It will be understood that other predetermined upper and lower limits can be selected and they can be expressed in different terms, such as voltage. Since the output voltage of the capacitor corresponds to the SOC of the capacitor, the computational load can be reduced when using the output voltage of the capacitor instead of the SOC. By using appropriately selected upper and lower limits, problems such as non-linear effects or unacceptably large discharge or charging currents that may be faced when the capacitor is substantially fully charged (e.g., above about 80%) or substantially fully discharged (e.g., below about 20%) when heating the electrolyte can be avoided.

[0030] At the start of the vaping session, the capacitor can be discharged until it reaches the threshold temperature or can be cycled between discharge and charge, after which the capacitor is heated by an external heater. By using an external heater, for example, more consistent heating can be provided during the heating or vaping phase. The threshold temperature can be, for example, about 180 - 230 °C. The heating provided by external heating can heat the capacitor to a target temperature (for example, about 280 °C).

[0031] The discharge and / or charge of the capacitor can be controlled based on an estimated or specified temperature. The temperature can be, for example, the estimated or specified temperature of the capacitor.

[0032] The temperature for controlling the discharge and / or charge of the capacitor can be measured using a temperature sensor. For example, the aerosol generating device can include a temperature sensor installed in proximity to the capacitor when the aerosol generating article is received within the device, or the temperature sensor can be configured to measure the temperature of the terminals of an external circuit that is in thermal and electrical contact with each electrode of the capacitor. The terminal can be the positive terminal of the external circuit.

[0033] The temperature can also be estimated from the electrical parameters of the capacitor. In other words, the capacitor can be used as a temperature sensor. It is known that the electrical parameters change with the temperature of the capacitor. It may be necessary to compensate for the change in the electrical parameters caused by the decrease in the amount of electrolyte over the course of the vaping session. One or more values of the electrical parameters of the capacitor can be estimated or specified using, for example, at least one of the measured values of current, voltage, and time taken when the capacitor is discharged or charged. The electrical parameter can be, for example, the internal resistance or capacitance of the capacitor. For example, the internal resistance R of the capacitor DC can be estimated or specified from the following formula.

Equation

[0034] The capacitance C of the capacitor can be estimated or specified from the following formula.

Equation

[0035] The electrical parameter can be used to estimate the temperature of the capacitor, for example, by using an appropriate linear or non-linear function or look-up table that associates the value of the electrical parameter with temperature. Using one or more values of the electrical parameter of the capacitor to estimate the temperature of the capacitor will be described in more detail below in relation to the temperature estimation step.

[0036] The discharge and / or charge of the capacitor can be controlled based on a comparison between the estimated or specified temperature and a target temperature or temperature profile.

[0037] The discharge and / or charging of the capacitor, and thus the heating of the electrolyte, can be controlled by varying the power by which the capacitor is discharged and / or charged through a switching circuit electrically connected between pairs of electrodes or terminals of the capacitor. For example, the discharge and / or charging power can be varied by controlling the switching device of the switching circuit such that the capacitor is discharged or charged intermittently using an appropriate duty cycle. For example, the switching device can be periodically enabled and disabled by a duty cycle that can be varied to control the rate at which the capacitor is discharged or charged. In particular, the time (or “pulse width”) during which the switching device is enabled can be varied based on the estimated or specified temperature of the capacitor. During the period in which the switching device is enabled, one or more switches (e.g., semiconductor switches) can be turned on and off as appropriate. One or more switches can be turned off during the period in which the switching device is disabled. The discharge and / or charging power can be adjusted each time the temperature of the capacitor is estimated or specified. The discharge power and the charging power can be controlled separately.

[0038] The switching device of the switching circuit can be controlled by a closed-loop controller having one or more controller constants (or gains). For example, the closed-loop controller can be a PID controller having a proportional constant, an integral constant, and a derivative constant. However, other closed-loop controllers can also be used. The one or more controller constants can be - an estimated or specified value of an electrical parameter of the capacitor, and - the estimated or specified temperature of the capacitor varied based on at least one of.

[0039] By changing one or more controller constants, when the electrolyte is inhaled as an aerosol by the user, if the electrical parameters of the capacitor change during the vaping session as a result of heating and / or a decrease in its amount, it becomes possible to adjust the discharge and / or charging of the capacitor. The electrical parameters can be electrical parameters that are expected to change together with the amount of electrolyte and / or the internal temperature of the capacitor, such as, for example, the internal resistance or capacitance of the capacitor. By being able to dynamically change the controller constants over the course of the vaping session, more consistent heating of the electrolyte can be provided, thereby improving the user experience. The value of the electrical parameter can be estimated or identified using at least one of the measured values of current, voltage, and time taken when the capacitor is discharged or charged. The one or more controller constants can be changed using, for example, a suitable automatic adjustment process that can use a neural network or any other type of adaptive control or learning process or model-based process. The automatic tuning process can use, for example, a look-up table that associates the electrical parameter or temperature with a specific controller constant.

[0040] The method may further include an identification step in which at least one of discharging and charging of the capacitor is performed over a period of time and the value of the electrical parameter of the capacitor is estimated or identified. The capacitor can be discharged and / or charged multiple times. The duration of each discharge or charge is preferably extremely short (e.g., about 10 - 100 ms), and the identification step is not intended to cause any significant discharge or charge of the capacitor as a result. The average value of the electrical parameter of the capacitor can be identified using at least one of the measured values of current, voltage, and time taken during each discharge or charge. The electrical parameter can be, for example, the internal resistance, capacitance, discharge rate or charge rate, SOC, or state of health (SOH) of the capacitor. The value of the electrical parameter (or the measured values of current, voltage, and time) can be - the operating parameters or state of the capacitor, and - the authenticity of the aerosol-generating article used to identify at least one of.

[0041] Identifying the operating parameters or state of a capacitor may include identifying whether an article is damaged or malfunctioning. If the capacitor does not respond as expected when discharged or charged during the identification step, it may indicate, for example, that there is a fault in the electrical connection to the switching circuit, that the capacitor is damaged, resulting in an internal short circuit, or that there may be insufficient electrolyte. The value of the electrical parameter of the capacitor estimated or identified during the identification step may be used, for example, to adjust the operating characteristics of the device. Authenticity may be established, for example, if the value of the electrical parameter is within a predetermined range, or above or below a predetermined threshold. If the article is not authentic, further operation of the device may be stopped.

[0042] The identification step may be performed by a controller before the preheating phase of the aerosol generating article. For example, the identification step may be performed when the article is inserted into the device.

[0043] The method may further include a temperature estimation step in which at least one of discharging and charging of the capacitor is performed over a period of time, and the value of the electrical parameter of the capacitor is estimated or identified. The capacitor may be discharged and / or charged multiple times. The average value of the electrical parameter of the capacitor may be identified using at least one of the measured values of current, voltage, and time taken during each discharge or charge. The value of the electrical parameter (or the measured values of current, voltage, and time) may be used, for example, to estimate the temperature of the capacitor using an appropriate linear or non-linear function or look-up table that associates the electrical parameter with temperature. The electrical parameter may be, for example, the internal resistance or capacitance of the capacitor that is directly proportional to the temperature of the capacitor.

[0044] The temperature estimation step may be performed by a controller at regular or irregular intervals, for example, during at least one of the preheating phase and a subsequent heating phase.

[0045] According to a second aspect of the present disclosure, there is provided an aerosol generation system comprising: an aerosol generating article comprising a capacitor, such as an electric double layer supercapacitor, the capacitor containing an electrolyte that generates an aerosol for inhalation by a user when heated; and an aerosol generation device for receiving the aerosol generating article, the aerosol generation device further comprising a controller adapted to carry out the method described above. An aerosol generation system comprising the above is provided.

[0046] The device may further comprise a switching circuit electrically connected between the pairs of electrodes of the capacitor.

[0047] The device may further comprise a heater adapted to heat the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0048]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0049] Here, embodiments of the present disclosure will be described by way of example only and with reference to the accompanying drawings.

[0050] Referring first to FIG. 1, an example of an aerosol-generating article 1 is shown in the figure. The article 1 has a proximal end 2 and a distal end 4.

[0051] 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 an electrolyte and provides electrical insulation.

[0052] The article 1 is substantially cylindrical.

[0053] At the proximal end 2, the article 1 includes a mouthpiece 12 having an outlet 14 through which a user can inhale an aerosol generated by heating the electrolyte. Although not shown, the proximal end cap 10a may include appropriate perforations or openings or may incorporate an appropriate aerosol-permeable membrane material so that the generated aerosol can pass through the end cap to the outlet 14.

[0054] Referring to FIG. 2, the capacitor 6 is an electric double layer supercapacitor and has a substantially cylindrical spiral wound (or "jelly roll") structure. 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 more clearly shown 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. 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. The positive and negative current collectors 22, 26 are, for example, aluminum foil layers.

[0055] The separators 20a, 20b are formed from tobacco materials such as porous tobacco sheets that release volatile compounds when heated. In an alternative arrangement (not shown), the separator can be formed from a suitable cellulose or polypropylene-based material, and the electrolyte can flow through a tobacco material such as crimped tobacco downstream of the capacitor in the aerosol flow path. The tobacco material can be positioned between the capacitor and the mouthpiece. The tobacco material adds flavor and nicotine to the aerosol. The heating provided by the capacitor also heats or warms the tobacco material, which promotes the release of volatile compounds. Instead of the tobacco material, a nicotine-free flavor source can be used.

[0056] 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 can include sodium chloride and glycerol and optionally polyvinyl alcohol as a gelling agent. However, other food-grade electrolytes can also be used. The capacitor 6 is pre-charged during the manufacturing process, packaged in a pre-charged state, and sold to the user.

[0057] 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 can be installed inside the outer casing of the article 1 so that they are not accessible to the user. This helps prevent accidental or intentional discharge of the capacitor 6 before the article is removably inserted into the aerosol generating device in preparation for the start of a vaping session.

[0058] Figure 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 can be inserted.

[0059] 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 can be limited when it is inserted into cavity 36 such that breaking device 38 is electrically connected to positive electrode 30 and breaking device 40 is electrically connected to negative electrode 32. Other methods can be used to ensure a reliable electrical connection. For example, the positive and negative terminals of the article can have an annular structure and appropriately positioned breaking devices can be coaxially installed with respect to each other so as to be in electrical contact with the terminals regardless of the angular orientation of the article relative to the device.

[0060] Device 34 includes a switching circuit 42 and a power source 44 such as a battery.

[0061] 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 can be operated by a controller 48 to control the discharge of capacitor 6 through switching circuit 42 and thus control the heating of the electrolyte. Controller 48 can include at least one microcontroller unit (MCU) or microprocessor unit (MPU).

[0062] After article 1 is inserted into device 34, capacitor 6 can 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 switching device 46. In addition, switching device 46 may include a resistor to prevent over - discharge current or an electrical load to enable constant - current discharge. If the discharge current is maintained at a predetermined value, the current sensor described later may be omitted. By discharging capacitor 6 through switching circuit 42, the heat in electrodes 16, 18 is dissipated. This heats the electrolyte and generates an aerosol that can 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 can lead to the miniaturization and weight reduction of device 34. In particular, the size and weight of power source 44 can be reduced. This is important because the power source is often the largest and heaviest component of the device. Optionally, the energy for heating can be provided entirely by capacitor 6, and power source 44 can 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.

[0063] Capacitor 6 can 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, the heat in electrodes 16, 18 is also dissipated, which heats the electrolyte and generates an aerosol that can be inhaled by the user through outlet 14 in mouthpiece 12. Therefore, charging capacitor 6 from power source 44 and then repeatedly discharging the capacitor through switching circuit 42 can generate heat.

[0064] The switching device 46 that can be used to enable the above-described discharging and charging of the capacitor 6 may include, for example, one or more switches. A discharge switch for controlling the discharge current of the capacitor 6 may be connected in series between the breaking devices 38, 40 that define the positive and negative terminals of the switching circuit 42. A 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, such as a transistor.

[0065] 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 by the capacitor. The measurement values provided by the current sensor and the voltage sensor are used, for example, to identify the electrical parameters of the capacitor, such as internal resistance or capacitance.

[0066] The device 34 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 can 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.

[0067] The device 34 includes a temperature sensor 52 for estimating or identifying the temperature of the capacitor 6. The temperature sensor 52 may be installed in the cavity 36 of the device 34, or may be adapted to measure the temperature of the positive terminal of the switching circuit 42 that is in thermal and electrical contact with the positive electrode 16 of the capacitor 6, particularly the positive current collector 22. The temperature measurement value provided by the temperature sensor 52 can be used, for example, to estimate the internal temperature of the capacitor 6 by applying an appropriate temperature offset.

[0068] Figure 6 represents a vaping session that includes a preheat phase PHP and a heating or vaporizing phase VP.

[0069] Before the start of the preheat phase, for example, when article 1 is inserted into device 34, an identification step (indicated by "(0)") is performed to identify the operating parameters and status of the capacitor and to check the authenticity of the aerosol-generating article. During the identification step, the pre-charged capacitor 6 is discharged multiple times (e.g., 5 times). Each discharge is for only a very short period (e.g., about 10 - 100 ms). The average value of the electrical parameters of capacitor 6, such as the internal resistance, capacitance, discharge rate, SOC or SOH of the capacitor, is determined using at least one of the measured values of current, voltage, and time during each discharge. The average value of the electrical parameters can be used to detect whether article 1 is damaged or defective. The average value of the electrical parameters of capacitor 6 can also be used to adjust the operating characteristics of the device. The authenticity of the aerosol-generating article 1 can be established, for example, when the average value of the electrical parameters is within a predetermined range or exceeds or falls below a predetermined threshold. If article 1 is not authentic, further operation of device 34 can be stopped.

[0070] During the vaping session, heating of the electrolyte is controlled by controlling the discharge and charge of capacitor 6 based on the estimated or determined temperature of the capacitor. The discharge and charge of capacitor 6 are controlled based on a comparison between the estimated or determined temperature and a target temperature or temperature profile. The discharge and charge power of capacitor 6 are changed by switching circuit 42. In particular, the discharge and charge power are changed by controlling the switching device 44 of switching circuit 42.

[0071] The discharge and charge power can be adjusted after each temperature estimation or determination.

[0072] During the preheating phase PHP, the capacitor 6 is repeatedly cycled between discharging and charging to continuously heat the capacitor (as indicated by "(1)"). The capacitor 6 is discharged and charged at specific discharge and charge powers as illustrated that can provide rapid heating of the capacitor towards the target temperature.

[0073] During the vaporizing phase VP, the discharging and charging of the capacitor are controlled to change the temperature of the capacitor according to a temperature profile to provide the desired heating of the electrolyte. For example, if the capacitor 6 is maintained at a specific temperature to provide substantially constant heating of the electrolyte, the capacitor can be discharged and charged at specific discharge and charge powers (as indicated by "(2)"), and the discharge and charge powers can be considered lower than the discharge and charge powers during the preheating phase PHP where more rapid heating is required. If it is necessary to lower the capacitor temperature, the switching device 44 can be disabled so that the capacitor is neither discharged nor charged and no heating is provided (as indicated by "(3)"). If it is necessary to raise the capacitor temperature to provide additional heating of the electrolyte, the capacitor can be discharged and charged at specific discharge and charge powers (as indicated by "(1)"), and the discharge and charge powers can be considered higher than the discharge and charge powers for maintaining the capacitor temperature (as indicated by "(2)"). FIG. 6 thus shows how the heating of the electrolyte can be changed by controlling the discharge and charge powers of the capacitor 6 to control the amount of heat dissipated within the electrodes.

[0074] The capacitor 6 is discharged and charged between a predetermined upper limit and a lower limit. In FIG. 6, the upper and lower limits are expressed in terms of SOC, the upper limit is about 50 - 80%, and the lower limit is about 20 - 40%.

[0075] FIG. 7 represents an alternative vaporizing session including the preheating phase PHP and the heating or vaporizing phase VP.

[0076] Before the start of the preheating phase PHP, for example, when article 1 is inserted into device 34, an identification step (indicated by "(0)") is performed to identify the operating parameters and state of the capacitor and to check the authenticity of the aerosol-generating article.

[0077] At the start of the preheating phase PHP, capacitor 6 is repeatedly cycled between discharging and charging until it reaches a threshold temperature (indicated by "(1)"). When the threshold temperature is reached, capacitor 6 is neither discharged nor charged, and the capacitor is heated by one or more heaters 50 (indicated by "(2)"). The threshold temperature can be, for example, about 180 - 230 °C. The heating provided by external heater 50 can heat capacitor 6 to a target temperature of about 280 °C.

[0078] When capacitor 6 is heated by one or more external heaters 50, a temperature estimation step is performed. In each temperature estimation step, capacitor 6 is charged and discharged a plurality of times (for example, 3 times). The average value of the electrical parameters of capacitor 6 is determined using at least one of the measured values of current, voltage, and time obtained each time the capacitor is discharged and / or charged. The average value of the electrical parameters is then used to estimate the temperature of capacitor 6. The electrical parameters can be, for example, the internal resistance or capacitance of capacitor 6 that is directly proportional to the temperature of the capacitor.

[0079] Referring to FIG. 8, the switching device 44 of the switching circuit 42 is controlled by a controller 48 including a closed-loop controller 54. The temperature measurement value T from the temperature sensor 52 is provided to the temperature estimation block 56. The temperature estimation block 56 also receives the value EP of the electrical parameters of capacitor 6, such as the internal resistance or capacitance that can be estimated or determined using the current and voltage measurement values. The temperature estimation block 56 outputs the estimated temperature ST of the capacitor based on the temperature measurement value T and / or the value EP of the electrical parameters.

[0080] An error E between the estimated capacitor temperature ST and the temperature profile TP is calculated and provided to a closed-loop controller 54 that controls the switching device 44.

[0081] The closed-loop controller 54 is a PID controller having a proportional constant K P , an integral constant K I and a derivative constant K D . The controller constants are changed by an auto-tuning block 58 based on at least one of the following. - The value EP of the electrical parameter of the capacitor 6, and - The temperature measurement value T.

[0082] By changing the controller constants, if the electrical parameters of the capacitor 6 change during a vaping session as a result of heating and / or a reduction in the amount thereof when inhaled as an aerosol by the user, it becomes possible to adjust the discharge and / or charging of the capacitor 6. Thereby, the controller can provide robust and accurate heating control throughout the vaping session.

[0083] The auto-tuning block 58 may use, for example, a neural network or any other type of adaptive control or learning process or model-based process. The auto-tuning block 58 may also use, for example, a look-up table that associates electrical parameters or temperature with specific controller constants.

[0084] Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications to those embodiments can be made without departing from the scope of the appended claims. Accordingly, the breadth and scope of the claims should not be limited to the exemplary embodiments described above.

[0085] 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.

[0086] Throughout this specification and the claims, unless the context clearly requires otherwise, words such as "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims

1. A method for heating an aerosol generating article (1) equipped with a capacitor (6), wherein the capacitor (6) contains an electrolyte, A method comprising: discharging and charging the capacitor (6) to heat the electrolyte, thereby generating an aerosol for inhalation by a user.

2. The method according to claim 1, wherein the capacitor (6) is circulated between discharge and charge.

3. The method according to claim 1, wherein at least one of the discharge and charge of the capacitor (6) is controlled based on an estimated or specified temperature.

4. The method according to claim 3, wherein the temperature is a measured temperature or is estimated or determined from at least the electrical parameters of the capacitor (6).

5. The method according to claim 3, wherein at least one of the discharge and charge of the capacitor (6) is controlled based on a comparison between the estimated or specified temperature (ET) and a target temperature or temperature profile (TP).

6. The method according to any one of claims 1 to 5, wherein the capacitor (6) further comprises a pair of electrodes (16, 18), and at least one of the discharge and charge of the capacitor (6) is controlled by changing the power to which the capacitor (6) is discharged and / or charged through a switching circuit (42) electrically connected between the pair of electrodes (16, 18).

7. The method according to claim 6, wherein the switching device (44) of the switching circuit (42) is controlled by a closed-loop controller (54) having one or more controller constants.

8. The one or more controller constants mentioned above are - The estimated or specified values ​​of the electrical parameters of the capacitor (6), - The estimated or specified temperature of the capacitor (6), The method according to claim 7, modified based on at least one of the following.

9. The method according to any one of claims 1 to 5, wherein the capacitor (6) is discharged until it reaches a threshold temperature, or is circulated between discharge and charge, and thereafter the capacitor (6) is heated by an external heater (50).

10. An identification step further comprising an identification step in which the capacitor (6) is discharged and charged over a period of time, and the values ​​of the electrical parameters of the capacitor (6) are estimated or identified, The values ​​of the aforementioned electrical parameters are - The operating parameters or state of the capacitor (6), - The authenticity of the aerosol-generating article (1), A method according to any one of claims 1 to 5, used to identify at least one of the following.

11. The method according to claim 10, wherein the identification step is performed before the preheating phase (PHP) of the aerosol generating article (1).

12. A temperature estimation step further comprising the steps by which the capacitor (6) is discharged and charged over a period of time, and the values ​​of the electrical parameters of the capacitor (6) are estimated or specified, The method according to any one of claims 1 to 5, wherein the value of the electrical parameter is used to estimate the temperature of the capacitor (6).

13. The method according to claim 12, wherein the temperature estimation step is performed at regular or irregular intervals between at least one of the preheating phase (PHP) and the subsequent heating or vaping phase (VP).

14. Aerosol generation system, an aerosol generating article (1) comprising a capacitor (6), wherein the capacitor (6) contains an electrolyte that generates an aerosol for inhalation by the user when heated, Aerosol generating device (34) that receives the aerosol generating article (1), further comprising a controller (48) adapted to implement the method described in any one of claims 1 to 5, An aerosol generation system equipped with the following features.

15. The aerosol generating system according to claim 14, wherein the capacitor (6) further comprises a pair of electrodes (16, 18), and the device (34) further comprises a switching circuit (42) electrically connected between the pair of electrodes (16, 18), and optionally a heater (50).

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