EP4684436A1

EP4684436A1 - Aerosol-generating system and a method of operating an aerosol-generating system

Info

Publication number: EP4684436A1
Application number: EP23718163.1A
Authority: EP
Inventors: Guoqiang CAI; Hongjie XU
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2023-03-21
Filing date: 2023-03-21
Publication date: 2026-01-28
Also published as: JP2026509501A; WO2024192678A1; KR20250155070A; CN120883379A

Abstract

There is provided an aerosol-generating system (100) for generating an inhalable aerosol from an aerosol-forming substrate (21). The aerosol-generating system comprises a lithium-ion battery (12). The battery comprises a cathode (122), the cathode comprising a cathode-active material (1222). The cathode-active material at least one compound selected from a first group of compounds and at least one compound selected from a second group of compounds. The first group of compounds comprises lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof. The second group of compounds comprises lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof.

Description

AEROSOL-GENERATING SYSTEM AND A METHOD OF OPERATING AN AEROSOL-GENERATING SYSTEM

The present disclosure relates to an aerosol-generating system and a method of operating an aerosol-generating system. The present disclosure also relates to use of a lithium-ion battery in an aerosol-generating system.
Aerosol-generating systems including an aerosol-generating device configured to generate an aerosol from an aerosol-forming substrate, such as a tobacco-containing substrate, are known in the art. To provide portability, it is known for such aerosol-generating devices to incorporate their own on-board power source, such as a battery. It is known for such aerosol-generating devices to use heat as a mechanism for evolving volatile compounds from an aerosol-forming substrate, with the battery providing the electrical energy needed to drive the heating process. The temperatures required to evolve volatile compounds from an aerosol-forming substrate can be in excess of 300 degrees Celsius. Where the aerosol-forming substrate is in liquid form, it is also known for an aerosol to be generated by bringing the substrate into contact with a vibrating membrane, with the battery providing the energy necessary to generate a driving signal to induce the vibration. The usage session for a consumable aerosol-generating article containing aerosol-forming substrate is of finite length, typically being of the order of minutes. Whether heat or vibration is used as the mechanism for generating an aerosol from an aerosol-forming substrate, the battery used to provide the electric energy necessary to drive the aerosol generation process is required to deliver a large amount of energy in a short amount of time. It is also desirable that the battery has a capacity sufficient to satisfy the energy requirements of the aerosol-generating device over at least one usage session.
Similarly, aerosol-generating systems including a charger for charging a battery of an aerosol-generating device are also known. To provide portability, it is known for such chargers to incorporate their own on-board power source, such as a battery. When the charger is coupled to an aerosol-generating device having its own respective battery, power from the battery of the charger may be used to charge the battery of the aerosol-generating device.
If a rechargeable battery was to be employed in either an aerosol-generating device or a charger as described above, the long term performance of the device or charger would be limited by the capacity of the battery progressively reducing with the number of charging cycles. Where the device or charger was compact in size, the size and capacity of the battery used in such a device or charger would be correspondingly reduced, thereby necessitating frequent recharging of the battery. The maximum number of charging cycles which a rechargeable battery may undergo whilst retaining a given level of performance is referred to as the “cycle life” of the battery. The level of performance may be quantified in terms of the energy capacity of the battery in a fully charged state.
It is desirable to provide an aerosol-generating system having an improved power source.
According to a first aspect of the present disclosure, there is provided an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate. The aerosol-generating system comprises a lithium-ion battery. The battery comprises a cathode, the cathode comprising a cathode-active material. The cathode-active material may comprise at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof, and at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof.
The first and second groups of compounds are suitable materials for use as the active ingredients of the cathode-active material.
Lithium-ion batteries are particularly suitable for aerosol-generating devices due to characteristics of high energy density and low self-discharge. The use of a cathode-active material including both lithium manganese iron phosphate (LMFP) and at least one compound from the second group defined above may facilitate providing the battery with an improved cycle life. An improved cycle life means that after a given number of charge cycles, the battery retains a greater proportion of the capacity that it possessed when in an “as-new” condition. Lithium manganese iron phosphate (LMFP) is an evolution of lithium iron phosphate (LFP) and both have similar physical properties. Therefore, it will be appreciated that the use of a cathode-active material including either one of lithium iron phosphate or lithium manganese iron phosphate (from the first group of compounds) may provide a battery with similar performance characteristics. For the second group of compounds, each of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) and lithium cobalt oxide (LCO) facilitate enhancing the energy density of the battery. Lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) and lithium cobalt oxide (LCO) provide similar nominal voltages.
By “charge cycle” is meant a period of use of the battery from being fully charged to fully discharged, and then being fully re-charged; the term “charge/discharge cycle” may be used in place of the term “charge cycle” . The term “capacity” , when referring to the capacity of a battery, is a measure of the maximum amount of charge able to be stored by the battery; the capacity is commonly expressed in units of Ampere-hours (A-h) .
In a preferred embodiment, the cathode-active material comprises lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) . As will be discussed in more detail in subsequent paragraphs, it has been found that the use of a cathode-active material comprising lithium manganese iron phosphate and lithium nickel manganese cobalt oxide provides an improved cycle life to the battery.
The cathode may form part of a discrete cell of the battery. The battery may comprise a single cell or a plurality of cells. Where the battery has a plurality of cells, the cathode of each of the cells may incorporate the cathode-active material as defined above.
The cathode may further comprise a cathode collector. The cathode collector may comprise aluminium or another suitable material. The cathode collector may be in the form of a foil and/or have a meshed construction.
Conveniently, a coating of the cathode-active material may be arranged over a surface of the cathode collector. Preferably, the coating may be applied directly to the surface of the cathode collector.
Advantageously, the cathode-active material may comprise a first layer and a second layer, the first layer applied over a surface of the cathode collector, and the second layer applied over the first layer. The first and second layers may have distinct material compositions. One of the first and second layers may comprise at least one compound from the first group of lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof. The other of the first and second layers may comprise at least one compound selected from the second group of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof. The first layer may be applied directly to the surface of the cathode collector. Preferably, the second layer is applied directly to the first layer, whereby the first and second layers are in surface contact with each other.
The cathode-active material may comprise lithium manganese iron phosphate and lithium nickel manganese cobalt oxide. Preferably, the weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide in the cathode-active material may lie within a range of between 1: 9 and 9: 1, or between 3: 7 and 7: 3, or between 3: 7 to 5: 5.
The cathode-active material may comprise lithium manganese iron phosphate as LiMn_iFe_1-iPO₄, wherein i lies within a range of between 0 and 1. Preferably, i lies within a range of between 0.5 and 0.7. The cathode-active material may further comprise lithium nickel manganese cobalt oxide as LiNi_pCo_qMn_rO₂, wherein p lies within a range of between 0.4 and 0.6, q lies within a range of between 0.1 and 0.3 and r lies within a range of between 0.2 and 0.4, wherein p + q + r = 1. In one preferred example, p has a value of 0.5, q has a value of 0.2 and r has a value of 0.3.
In another embodiment, the cathode-active material may comprise lithium iron phosphate (LFP) (instead of lithium iron manganese phosphate) and lithium nickel manganese cobalt oxide (NMC) .
The battery may comprise an electrolyte comprising a lithium salt. The lithium salt may function as a source of lithium ions for the battery. The lithium salt may preferably comprise or consist of LiPF₆.
Preferably, the cathode-active material may further comprise a solvent, a binder, a conductive agent and a stabiliser.
The solvent may be aqueous or non-aqueous. The solvent may comprise one or more of N-methyl-2-pyrrolidone (NMP) , dimethylformamide (DMF) , dimethylacetamide, N, N-dimethylaminopropylamine, ethylene oxide and tetrahydrofuran (THF) .
The binder may facilitate mixing the constituent ingredients of the cathode-active material into a paste or a slurry. The binder may also facilitate adhering the cathode-active material to the cathode collector. The binder may comprise one or more of polyvinylidenefluoride (PVDF) , polyhexafluoropropylene-polyvinylidenefluoride copolymer, poly (vinylacetate) , polyvinylalcohol, polyethyleneoxide (PEO) , polyvinylpyrrolidone (PVP) , alkylated polyethyleneoxide, polyvinylether (PVE) , poly (methylmethacrylate) (PMMA) , poly (ethylacrylate) (PEA) , polytetrafluorethylene (PTFE) , polyvinylchloride (PVC) , polyacrylonitrile (PAN) , polyvinylpyridine, styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber. The binder may be present in the cathode-active material in a concentration of 0.1%to 30%by weight of the cathode-active material, or preferably in a concentration of 1%to 10%by weight of the cathode-active material.
The conductive agent may comprise one or more of a graphitic agent, a carbon-black agent, a metal and a metallic compound agent. Where the conductive agent comprises a graphitic agent, the graphitic agent may comprise one or more of artificial graphite and natural graphite. Where the conductive agent comprises a carbon-black agent, the carbon-black agent may comprise one or more of acetylene black, ketjen black, denka black, thermal black and channel black. Where the conductive agent comprises a metal or metallic compound agent, the metal or metallic compound agent may comprise one or more of Sn, SnO₂, SnPO₄, TiO₂, KTiO₃, LaSrCoO₃ and LaSrMnO₃. The conductive agent may be present in the cathode-active material in a concentration of 0.1%to 10%by weight of the cathode-active material. Limiting the concentration of the conductive agent to be no more than 10%by weight of the cathode-active material may be beneficial in terms of the energy density per unit weight. Maintaining the concentration of the conductive agent to be no less than 0.1%by weight of the cathode-active material may be beneficial in enhancing electrochemical characteristics of the cathode-active material.
The stabiliser may comprise one or more of carboxylmethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose.
The aerosol-generating system may comprise an anode-active material comprising graphite, carbon, silicon, or a combination thereof.
Advantageously, the lithium-ion battery may be a rechargeable battery.
Preferably, the system comprises at least one of an aerosol-generating device and a charger for charging a power source of an aerosol-generating device. Where the system comprises an aerosol-generating device, the battery may form part of the aerosol-generating device. The battery may provide electrical power to support functioning of the aerosol-generating device in generating an inhalable aerosol from an aerosol-forming substrate. Where the system comprises a charger, the battery may form part of the charger.
In an example where the battery forms part of the aerosol-generating device, the aerosol-generating device may comprise an electrically-powered heating arrangement and control electronics configured to control a supply of electricity from the battery to the heating arrangement. In one example, the electrically-powered heating arrangement may comprise a resistive heating element. In another example, the electrically-powered heating arrangement may comprise an inductor configured to induce eddy currents into a susceptor. The susceptor may form part of the electrically-powered heating arrangement of the device. Alternatively, the susceptor may form part of an aerosol-generating article for use with the aerosol-generating device, the article containing an aerosol-forming substrate. The susceptor may be embedded within the aerosol-forming substrate. The control electronics may be configured to provide a continuous or continual supply of electricity to the heating arrangement over a usage session. Alternatively, the control electronics may be configured to provide a pulsed supply of electricity to the heating arrangement over a usage session.
The aerosol-generating device may comprise a membrane for evolving an aerosol from an aerosol-forming substrate through vibration of the membrane. An actuator may be coupled to the membrane. The aerosol-generating device may further comprise control electronics configured to control a supply of electricity from the battery to the actuator to drive vibration of the membrane. In some embodiments, the membrane may be provided as an alternative to the use of an electrically powered heating arrangement, whereas in other embodiments, the membrane may be provided in addition to the electrically powered heating arrangement. The battery may form part of the aerosol-generating device.
The aerosol-generating device may be configured to receive an aerosol-generating article comprising the aerosol-forming substrate.
Preferably, the aerosol-generating device may be configured in size and mass to be hand-held. Conveniently, the aerosol-generating device may be generally elongate; by way of example, the aerosol-generating device may be generally cylindrical.
The battery may form part of the charger. The charger may comprise control electronics configured to operate in each of a first mode and a second mode. The first mode may be configured to discharge the battery in order to charge a corresponding battery of an aerosol-generating device. The second mode may be configured to charge the battery of the charger from an external power source.
In another aspect of the present disclosure, there is provided a method of operating an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate. The aerosol-generating system comprises a lithium-ion battery. The battery comprises a cathode, the cathode comprising a cathode-active material. The cathode-active material may comprise at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof, and at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof. The method may comprise connecting the aerosol-forming substrate to the aerosol-generating system, and using the aerosol-generating system to generate aerosol from the aerosol-generating substrate.
In a further aspect of the present disclosure, there is provided use of a lithium-ion battery in an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate. The battery comprises a cathode, the cathode comprising a cathode-active material. The cathode-active material may comprise at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof; and at least one member selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof.
In a further aspect of the present disclosure, the cathode-active material may comprise lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) as active ingredients of the cathode-active material. Both lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) have similar physical properties, with the use of both compounds in the cathode-active material harnessing the individual benefits associated with each of lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) .
In a further aspect of the present disclosure, the cathode-active material may comprise at least two of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) as active ingredients of the cathode-active material. Preferably, the cathode-active material comprises lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) . Lithium nickel manganese cobalt oxide (NMC) has an energy density of about 150-220 Wh/kg, with lithium cobalt oxide (LCO) having an energy density of about 150-200 Wh/kg.
As used herein, the term “aerosol-generating system” is used to describe a plurality of elements configured to provide an interaction with an aerosol-forming substrate to generate an aerosol.
As used herein, the term “aerosol-generating device” is used to describe a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. Preferably, the aerosol-generating device is a smoking device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol that is directly inhalable into a user’s lungs thorough the user’s mouth. The aerosol-generating device may be a holder for a smoking article.
Preferably, the aerosol-generating article is a smoking article that generates an aerosol that is directly inhalable into a user’s lungs through the user’s mouth. More preferably, the aerosol-generating article is a smoking article that generates a nicotine-containing aerosol that is directly inhalable into a user’s lungs through the user’s mouth.
As used herein, the term “aerosol-forming substrate” denotes a substrate consisting of or comprising an aerosol-forming material that is capable of releasing volatile compounds upon heating to generate an aerosol.
As used herein, the term “aerosol-forming material” denotes a material that is capable of releasing volatile compounds upon heating to generate an aerosol. An aerosol-forming substrate may comprise or consist of an aerosol-forming material.
As used herein, the terms “upstream” and “downstream” are used to describe the relative positions of elements, or portions of elements, of the heated aerosol-generating article in relation to the direction in which a user draws on the aerosol-generating article during use thereof.
Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. However, the aerosol-forming substrate may comprise both solid and liquid components. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.
Preferably, the aerosol-forming substrate comprises nicotine. More preferably, the aerosol-forming substrate comprises tobacco. Alternatively or in addition, the aerosol-forming substrate may comprise a non-tobacco containing aerosol-forming material.
If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise, for example, one or more of: powder, granules, pellets, shreds, strands, strips or sheets containing one or more of: herb leaf, tobacco leaf, tobacco ribs, expanded tobacco and homogenised tobacco.
Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavour compounds, which are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain one or more capsules that, for example, include additional tobacco volatile flavour compounds or non-tobacco volatile flavour compounds and such capsules may melt during heating of the solid aerosol-forming substrate.
Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may take the form of powder, granules, pellets, shreds, strands, strips or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier in the form of, for example, a sheet, foam, gel or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern in order to provide a non-uniform flavour delivery during use.
In a preferred embodiment, the aerosol-forming substrate comprises homogenised tobacco material. As used herein, the term “homogenised tobacco material” refers to a material formed by agglomerating particulate tobacco.
Preferably, the aerosol-forming substrate comprises a gathered sheet of homogenised tobacco material. As used herein, the term “sheet” refers to a laminar element having a width and length substantially greater than the thickness thereof. As used herein, the term “gathered” is used to describe a sheet that is convoluted, folded, or otherwise compressed or constricted substantially transversely to the longitudinal axis of the aerosol-generating article.
Preferably, the aerosol-forming substrate comprises an aerosol former. As used herein, the term “aerosol former” is used to describe any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol and that is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article.
Suitable aerosol-formers are known in the art and include, but are not limited to: polyhydric alcohols, such as propylene glycol, triethylene glycol, 1, 3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di-or triacetate; and aliphatic esters of mono-, di-or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as propylene glycol, triethylene glycol, 1, 3-butanediol and, most preferred, glycerine.
The aerosol-forming substrate may comprise a single aerosol former. Alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol formers.
The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.
Example Ex1: An aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising:
at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof; and
at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof.
Example Ex1A: An aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) .
Example Ex1B: An aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising at least two of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) .
Example Ex1C: An aerosol-generating system according to Ex1B, wherein the cathode-active material comprises lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) .
Example Ex2: An aerosol-generating system according to any one of Ex1 to Ex1C, the cathode further comprising a cathode collector.
Example Ex3: An aerosol-generating system according to Ex2, wherein the cathode collector comprises aluminium.
Example Ex4: An aerosol-generating system according to either one of Ex2 or Ex3, wherein a coating of the cathode-active material is arranged over a surface of the cathode collector.
Example Ex5: An aerosol-generating system according to Ex4, wherein the coating is applied directly to the surface of the cathode collector.
Example Ex6: An aerosol-generating system according to any one of Ex2 to Ex5, wherein the cathode-active material comprises a first layer and a second layer, the first layer applied over a surface of the cathode collector, the second layer applied over the first layer, the first and second layers having distinct material compositions.
Example Ex6A: An aerosol-generating system according to Ex6, wherein one of the first and second layers comprises at least one compound selected from the first group of lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof; and the other of the first and second layers comprises at least one compound selected from the second group of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof.
Example Ex7: An aerosol-generating system according to Ex6, wherein the first layer is applied directly to the surface of the cathode collector.
Example Ex8: An aerosol-generating system according to either one of Ex6 or Ex7, wherein the second layer is applied directly to the first layer.
Example Ex9: An aerosol-generating system according to any one of Ex1 to Ex8, wherein the cathode-active material comprises lithium manganese iron phosphate and lithium nickel manganese cobalt oxide.
Example Ex10: An aerosol-generating system according to Ex9, wherein the weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide in the cathode-active material lies within a range of between 1: 9 and 9: 1, or between 3: 7 and 7: 3, or between 3: 7 and 5: 5.
Example Ex11: An aerosol-generating system according to any one of Ex1 to Ex10, wherein the cathode-active material comprises lithium manganese iron phosphate as LiMn_iFe_1-iPO₄, wherein i lies within a range of between 0 and 1.
Example Ex12: An aerosol-generating system according to Ex11, wherein i lies within a range of between 0.5 and 0.7.
Example Ex13: An aerosol-generating system according to either one of Ex11 or Ex12, wherein the cathode-active material further comprises lithium nickel manganese cobalt oxide as LiNi_pCo_qMn_rO₂, wherein p lies within a range of between 0.4 and 0.6, q lies within a range of between 0.1 and 0.3 and r lies within a range of between 0.2 and 0.4, wherein p + q + r = 1.
Example Ex14: An aerosol-generating system according to Ex13, wherein p has a value of 0.5, q has a value of 0.2 and r has a value of 0.3.
Example Ex14A: An aerosol-generating system according to any one of Ex1 to Ex8, wherein the cathode-active material comprises lithium iron phosphate and lithium nickel manganese cobalt oxide.
Example Ex15: An aerosol-generating system according to any one of Ex1 to Ex14A, wherein the battery comprises an electrolyte comprising a lithium salt, the lithium salt preferably comprising or consisting of LiPF₆.
Example Ex16: An aerosol-generating system according to any one of Ex1 to Ex15, wherein the cathode-active material further comprises a solvent, a binder, a conductive agent and a stabiliser.
Example Ex17: An aerosol-generating system according to Ex16, wherein the solvent comprises one or more of N-methyl-2-pyrrolidone (NMP) , dimethylformamide (DMF) , dimethylacetamide, N, N-dimethylaminopropylamine, ethylene oxide and tetrahydrofuran (THF) .
Example Ex18: An aerosol-generating system according to either one of Ex16 or Ex17, wherein the binder comprises one or more of polyvinylidenefluoride (PVDF) , polyhexafluoropropylene-polyvinylidenefluoride copolymer, poly (vinylacetate) , polyvinylalcohol, polyethyleneoxide (PEO) , polyvinylpyrrolidone (PVP) , alkylated polyethyleneoxide, polyvinylether (PVE) , poly (methylmethacrylate) (PMMA) , poly (ethylacrylate) (PEA) , polytetrafluorethylene (PTFE) , polyvinylchloride (PVC) , polyacrylonitrile (PAN) , polyvinylpyridine, styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber.
Example Ex19: An aerosol-generating system according to any one of Ex16 to Ex18, wherein the binder is present in the cathode-active material in a concentration of 0.1%to 30%by weight of the cathode-active material, or 1%to 10%by weight of the cathode-active material.
Example Ex20: An aerosol-generating system according to any one of Ex16 to Ex19, wherein the conductive agent comprises one or more of a graphitic agent, a carbon-black agent, a metal and a metallic compound agent.
Example Ex21: An aerosol-generating system according to Ex20, wherein the graphitic agent comprises one or more of artificial graphite and natural graphite.
Example Ex22: An aerosol-generating system according to either one of Ex20 or Ex21, wherein the carbon-black agent comprises one or more of acetylene black, ketjen black, denka black, thermal black and channel black.
Example Ex23: An aerosol-generating system according to any one of Ex20 to Ex22, wherein the metal or metallic compound agent comprises one or more of Sn, SnO₂, SnPO₄, TiO₂, KTiO₃, LaSrCoO₃ and LaSrMnO₃.
Example Ex24: An aerosol-generating system according to any one of Ex16 to Ex23, wherein the conductive agent is present in the cathode-active material in a concentration of 0.1%to 10%by weight of the cathode-active material.
Example Ex25: An aerosol-generating system according to any one of Ex16 to Ex24, wherein the stabiliser comprises one or more of carboxylmethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose.
Example Ex26: An aerosol-generating system according to any one of Ex1 to Ex25, comprising an anode-active material comprising graphite, carbon, silicon, or a combination thereof.
Example Ex27: An aerosol-generating system according to any one of Ex1 to Ex26, wherein the lithium-ion battery is a rechargeable battery.
Example Ex28: An aerosol-generating system according to any one of Ex1 to Ex27, wherein the system comprises at least one of an aerosol-generating device and a charger for charging a power source of an aerosol-generating device.
Example Ex29: An aerosol-generating system according to Ex28, wherein the battery forms part of the aerosol-generating device.
Example Ex30: An aerosol-generating system according to Ex28 and Ex29, wherein the aerosol-generating device comprises:
an electrically-powered heating arrangement; and
control electronics configured to control a supply of electricity from the battery to the heating arrangement.
Example Ex31: An aerosol-generating system according to Ex30, wherein the electrically-powered heating arrangement comprises a resistive heating element.
Example Ex32: An aerosol-generating system according to Ex30, wherein the electrically-powered heating arrangement comprises an inductor configured to induce eddy currents into a susceptor.
Example Ex33: An aerosol-generating system according to Ex32, wherein the electrically-powered heating arrangement further comprises a susceptor.
Example Ex34: An aerosol-generating system according to any one of Ex30 to Ex33, wherein the control electronics are configured to provide a continuous or continual supply of electricity to the heating arrangement over a usage session.
Example Ex35: An aerosol-generating system according to any one of Ex30 to Ex33, wherein the control electronics are configured to provide a pulsed supply of electricity to the heating arrangement over a usage session.
Example Ex36: An aerosol-generating system according to any one of Ex28 to Ex35, wherein the aerosol-generating device comprises:
a membrane for evolving an aerosol from an aerosol-forming substrate through vibration of the membrane;
an actuator coupled to the membrane; and
control electronics configured to control a supply of electricity from the battery to the actuator to drive vibration of the membrane.
Example Ex37: An aerosol-generating system according to any one of Ex28 to Ex36, wherein the aerosol-generating device is configured to receive an aerosol-generating article comprising the aerosol-forming substrate.
Example Ex38: An aerosol-generating system according to any one of Ex1 to Ex37, the system further comprising an aerosol-generating article comprising the aerosol-forming substrate.
Example Ex39: An aerosol-generating system according to Ex28, wherein the battery forms part of the charger.
Example Ex40: An aerosol-generating system according to Ex39, wherein the charger comprises:
control electronics configured to operate in each of a first mode and a second mode, the first mode configured to discharge the battery in order to charge a corresponding battery of an aerosol-generating device, the second mode configured to charge the battery of the charger from an external power source.
Example Ex41: A method of operating an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising:
at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof; and
at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof;
the method comprising connecting the aerosol-forming substrate to the aerosol-generating system, and using the aerosol-generating system to generate aerosol from the aerosol-generating substrate.
Example Ex41A: A method of operating an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) ;
the method comprising connecting the aerosol-forming substrate to the aerosol-generating system, and using the aerosol-generating system to generate aerosol from the aerosol-generating substrate.
Example Ex41B: A method of operating an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:
a lithium-ion battery;
wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising at least two of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) and lithium cobalt oxide (LCO) ;
the method comprising connecting the aerosol-forming substrate to the aerosol-generating system, and using the aerosol-generating system to generate aerosol from the aerosol-generating substrate.
Example Ex41C: A method according to Ex41B, wherein the cathode-active material comprises lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) .
Example Ex42: Use of a lithium-ion battery in an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising:
at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate (LMFP) , lithium iron phosphate (LFP) , or a combination thereof; and
at least one member selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) , lithium cobalt oxide (LCO) , or a combination thereof.
Example Ex42A: Use of a lithium-ion battery in an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising lithium manganese iron phosphate (LMFP) and lithium iron phosphate (LFP) .
Example Ex42B: Use of a lithium-ion battery in an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, wherein the battery comprises a cathode, the cathode comprising a cathode-active material;
the cathode-active material comprising at least two of lithium nickel manganese cobalt oxide (NMC) , lithium nickel cobalt aluminium oxide (NCA) and lithium cobalt oxide (LCO) .
Example Ex42C: Use of a lithium-ion battery according to Ex42B, wherein the cathode-active material comprises lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) . Examples will now be further described with reference to the figures, in which:
Figure 1 illustrates a schematic view of a first embodiment of an aerosol-generating system according to the present disclosure;
Figure 2 illustrates a schematic view of a second embodiment of an aerosol-generating system according to the present disclosure;
Figure 3 illustrates a schematic view of a third embodiment of an aerosol-generating system according to the present disclosure;
Figure 4 illustrates a schematic view of a fourth embodiment of an aerosol-generating system according to the present disclosure;
Figure 5 illustrates a schematic view of a first embodiment of a lithium-ion battery according to the present disclosure, which is suitable for use in the aerosol-generating systems of Figures 1 to 4;
Figure 6 illustrates a schematic view of a second embodiment of lithium-ion battery according to the present disclosure, which is suitable for use in the aerosol-generating systems of Figures 1 to 4;
Figure 7 is a graph showing the change in battery capacity with increasing number of charge cycles for four examples of lithium-ion battery, each battery differing in the composition of cathode-active material employed, with charging and discharging of the batteries performed at a temperature of 25 degrees Celsius;
Figure 8 corresponds to Figure 7, but with charging and discharging of the batteries being performed at a temperature of 40 degrees Celsius.
Figure 1 shows an exemplary aerosol-generating system 100. The system 100 includes an aerosol-generating device 10. The device 10 is a hand-held aerosol generating device, and has an elongate shape defined by a housing 11 that is substantially cylindrical in form. The housing 11 contains a lithium-ion battery 12, control electronics 13 and an electrically powered heating element 14. A blind cylindrical cavity 15 extends from a proximal end 16 of the housing 11. The heating element 14 extends from a closed end 17 of the cavity 15 longitudinally along the cavity towards the proximal end 16. The heating element 14 is a resistive heating element and has a blade-shaped profile; in an alternative embodiment, the heating element may have a pin-shaped profile. A pair of electrical charging contacts 18a, b extend between the battery 12 and a distal end 19 of the housing 11.
The system 100 of Figure 1 also includes an aerosol-generating article 20. The article 20 has the form of a cylindrical rod, the rod formed by a combination of an aerosol-forming substrate 21 and a filter element 22. The aerosol-forming substrate 21 and filter element 22 are co-axially aligned and circumferentially enclosed in a wrapper 23 of cigarette paper. The aerosol-forming substrate 21 is a solid aerosol-forming substrate comprising tobacco. However, in alternative embodiments, the aerosol-forming substrate 21 may instead be a liquid aerosol-forming substrate or formed of a combination of liquid and solid aerosol-forming substrates. The filter element 22 serves as a mouthpiece of the aerosol-generating article 20. The aerosol-generating article 20 has a diameter substantially equal to the diameter of the cavity 15 of the device 10 and a length longer than a depth of the cavity. The aerosol-generating article 10 is inserted into the cavity 15 until an upstream end 25 of the aerosol-forming substrate 21 touches or is immediately adjacent to the closed end 17 of the cavity. As the aerosol-generating article 20 is inserted into the cavity 15, the resistive heating element 14 of the aerosol-generating device 10 pierces and penetrates within the aerosol-forming substrate 21 of the article 20. When the aerosol-generating article 20 is received in the cavity 15 of the device 10, the portion of the article containing the filter element 22 extends outside of the cavity to allow a user to draw on the article, in a similar manner to a conventional cigarette.
The lithium-ion battery 12 serves as a source of electrical power to support operation of the aerosol-generating device 10. The control electronics 13 is configured to control a supply of electricity from the battery 12 to the resistive heating element 14 during use of the device 10 over a usage session. The control electronics 13 includes or is coupled to a memory module 13a.
In use, the control electronics 13 controls the supply of electricity from the battery 12 to the resistive heating element 14 in accordance with instructions and data stored in the memory module 13a. The memory module 13a contains instructions and data governing when and the duration for which electrical energy is supplied from the battery 12 to the heating element 14. The instructions and data in the memory module 13a may include a target thermal profile for the heating element 14 over a usage session. The target thermal profile defines a target operating temperature for the heating element 14. The target operating temperature may be defined as a function of the time elapsed in a given usage session, or as a function of the number of puffs applied to the article 20 in a given usage session, or a combination thereof. The duration of the usage session may be defined by the first to occur of the usage session having continued for a predetermined maximum time duration and the number of puffs applied to the aerosol-generating article 20 having reached a predetermined maximum number of applied puffs. By way of example, the predetermined maximum time duration may be 6 minutes and the predetermined maximum number of applied puffs may be 14.
Figure 2 shows an alternative aerosol-generating system 100’ to the system 100 of Figure 1. The systems 100’, 100 differ in the configuration of the aerosol-generating device 10’ and aerosol-generating article 20’ of Figure 2 compared to the device 10 and article 20 of Figure 1. Instead of the resistive heating element 14 of the device 10 of Figure 1, the aerosol-generating device 10’ of Figure 2 has an induction coil 141 provided within the housing 11. The induction coil 141 surrounds a tubular inner wall of the housing 11, the tubular inner wall defining the cavity 15. A susceptor 241 is embedded within the aerosol-forming substrate 21 of the aerosol-generating article 20’.
In an alternative embodiment to Figure 2, the susceptor may instead form part of the aerosol-generating device 10’. In one such alternative example, the susceptor may extend from the closed end 17 of the cavity 15 longitudinally along the cavity, in a similar manner to the resistive heating element 14 for the embodiment of Figure 1. In another alternative example, the susceptor may define the tubular inner wall of the cavity 15.
During use of the aerosol-generating system 100’ of Figure 2, the control electronics 13 controls the supply of electricity from the lithium-ion battery 12 to the induction coil 141 in accordance with instructions and data stored in the memory module 13a, in a similar manner to the methodology described with reference to the embodiment of Figure 1. When the aerosol-generating article 20’ is inserted into the cavity 15 such that the upstream end 25 of the aerosol-forming substrate 21 touches or is immediately adjacent to the closed end 17 of the cavity 15, the susceptor 241 lies within the induction coil 141. Alternating current flow through the induction coil 141 generates an alternating magnetic field, which in turn induces eddy currents through and consequent heating of the susceptor 241.
Figure 3 is a third embodiment of aerosol-generating system 100”, incorporating the aerosol-generating device 10 and aerosol-generating article 20 of the embodiment of Figure 1. However, the system 100” additionally includes a charger 30. The charger 30 has a housing 31. The housing 31 contains a lithium-ion battery 32 and control electronics 33. The control electronics 33 includes a memory module 33a containing instructions and data for use by the control electronics. The housing 31 includes a blind cylindrical cavity 34 slightly larger in size than the diameter of the aerosol-generating device 10. The cavity 34 is dimensioned to receive part of the length of the aerosol-generating device 10. Electrical charger contacts 35a, b are provided at a base end 36 of the cavity 34. The device 10 is inserted into the cavity 34 distal end 19 first until the pair of electrical charging contacts 18a, b of the device 10 contact the pair of electrical charging contacts 35a, b of the charger 30. When the charger 30 is activated with the aerosol-generating device 10 received in the cavity 34, the control electronics 33 operates in a first operational mode. In the first operational mode, the control electronics 33 access the instructions and data in the memory module 33a to control the supply of electricity from the battery 32 in order to recharge the lithium-ion battery 12 of the device 10. As shown in Figure 3, the charger 30 also includes a exterior port 37 coupled to an end of the housing 31. The port 37 is configured for connection to an external power supply (for example, to a mains electricity supply) to enable recharging of the lithium-ion battery 32 of the charger 30. The port 37 is electrically coupled to the lithium-ion battery 32 via the controller 33. When the charger 30 is activated with the port 37 connected to the external power supply, the control electronics 33 operates in a second operational mode. In the second operational mode, the control electronics 33 accesses the instructions and data in the memory module 33a to control the supply of power from the external power supply in order to recharge the battery 32 of the charger.
Figure 4 shows a further alternative aerosol-generating system 100”’. The system 100”’ of Figure 4 employs an aerosol-generating device 10”’ configured to generate aerosol from a liquid aerosol-forming substrate through vibration of a membrane in contact with the substrate, rather than through heating of the substrate. In common with the aerosol-generating devices 10, 10’ of Figures 1 to 3, the aerosol-generating device 10”’ of Figure 4 has a housing 11 containing a lithium-ion battery 12 and control electronics 13. The housing 11 has a first housing part 11a and a second housing part 11b. The first housing part 11a is in the form of a cylindrical tube and is connected to the second housing part 11b. The second housing part 11b is conical in shape and defines a mouthpiece of the aerosol-generating device 10”’, with an opening provided at one end of the mouthpiece. A replaceable/disposable cartridge 200 is located within the housing 11. The cartridge 200 contains a reservoir of liquid aerosol-forming substrate 201. A feed assembly 212 is fluidically coupled to and located downstream of the cartridge 200. The feed assembly 212 may be a passive structure, such as a wicking element. Alternatively, the feed assembly 212 may be an active feed assembly (such as a pump or similar) powered by the battery 12. A vibratory aerosolisation module 142 is provided downstream of the feed assembly 212. The aerosolisation module 142 includes an actuator assembly 142a coupled to a perforated membrane 142b. The actuator assembly 142a is coupled to the battery 12 via the control electronics 13. In use, the control electronics 13 controls the supply of electricity from the lithium-ion battery 12 to the actuator assembly 142a in accordance with instructions and data stored in the memory module 13a. The control electronics 13 provides a driving signal to the actuator assembly 142a, with the actuator assembly inducing a vibratory response from the membrane 142b. The feed assembly 212 feeds liquid aerosol-forming substrate 201 from the cartridge 200 to one side of the membrane 142b. Vibration of the membrane 142b results in the substrate 201 being ejected through perforations of the membrane and dispersed as a spray of aerosol droplets through the opening in the mouthpiece 11b -as shown schematically in Figure 4.
For all of the embodiments of aerosol-generating device 10, 10’, 10”’ in Figures 1 to 4, the lithium-ion battery 12 serves as a source of electrical energy to facilitate generation of an inhalable aerosol from an aerosol-forming substrate 21 (Figures 1 to 3) , 201 (Figure 4) -whether through heating (as in the embodiments of Figures 1 to 3) , or through vibration (as in the embodiment of Figure 4) . In all of the embodiments illustrated in the figures, the aerosol-generating device 10, 10’, 10”’ has a size and a mass which enable it to be hand-held by a user. The battery 12 provides high levels of energy over a short finite period of time -specifically, over a usage session. The battery 12 only has sufficient capacity to complete a predetermined number of usage sessions. On completion of the predetermined number of usage sessions, the battery 12 is recharged. The predetermined number of usage sessions may be a single usage session, or may be two or more usage sessions.
For the embodiment of Figure 3, the lithium-ion battery 32 of the charger 30 contains sufficient energy to fully recharge the lithium-ion battery 12 of the aerosol-generating device 10. For the illustrated embodiment, the battery 32 of the charger 30 has a capacity sufficient to fully recharge the battery 12 of the device 10 for at least two recharge cycles, before the battery 32 requires recharging.
The following paragraphs describe an exemplary configuration for the lithium-ion battery 12 with reference to Figures 4 to 6. The lithium-ion battery 32 of the charger 30 has a configuration corresponding to that of battery 12, only differing in that the battery 32 has a larger capacity and physical size to battery 12. So, the comments below in respect of battery 12 also apply to battery 32.
Figure 5 illustrates a schematic view of the lithium-ion battery 12 as employed in the aerosol-generating devices 10, 10’, 10”’ of Figures 1 to 4. Figure 5 also includes a representation of the external circuit which is formed by connection of the battery 12 to the control electronics 13 and other electrical loads of the aerosol-generating device 10. The other electrical loads would include the resistive heater element 14 of Figures 1 and 3, the induction coil 141 of Figure 2 and the actuator assembly 142a of the vibratory aerosolisation module 142 of Figure 4. The control electronics 13 and these other electrical loads are represented by reference sign “L” in Figure 5.
Figure 5 shows a single cell of the lithium-ion battery 12. The cell of the lithium-ion battery 12 has a pair of electrodes in the form of an anode 121 and a cathode 122. The anode and cathode are spaced apart from each other in an electrolyte 123. A separator 124 is positioned in the cell between the anode 121 and cathode 122. It will be appreciated that in other embodiments, the battery 12 may comprise multiple cells.
The anode 121 has an anode collector 1211 formed of copper foil. The anode collector 1211 is coated with an anode-active material 1212. The anode-active material 1212 is formed of graphite. The cathode 122 has a cathode collector 1221 formed of aluminium foil. The cathode collector 1221 is coated with a cathode-active material 1222. The cathode-active material 1222 is formed of at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof; and at least one member selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof.
The electrolyte 123 is formed of a non-aqueous organic solvent and a lithium salt. For the embodiment described, the lithium salt is LiPF₆. However, it will be appreciated that in other embodiments, alternative forms of lithium salt may be used.
When the battery 12 is being discharged (for example, when providing electricity to the control electronics 13 and other electrical loads of the aerosol-generating devices 10, 10’, 10”’ previously described) , lithium ions flow from the cathode 122 to the anode 121 through the electrolyte 123 and separator 124 (as indicated by the broken arrow in Figure 5) . Further, electrons flow from the anode 121 towards the cathode 122 via the external circuit and loads L. The direction of passage of the ions reverses when the battery 12 is being charged, i.e. from the anode 121 towards the cathode 122.
Figure 6 differs from the battery 12 of Figure 5 in that the cathode-active material is applied as two distinct layers 1222a, 1222b. The first layer 1222a comprises lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof, and is applied directly onto the surface of the cathode collector 1221. The second layer 1222b comprises at least one of lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof. The second layer 1222b is applied directly onto the surface of the first layer 1222a.
In tests, four different exemplary batteries 12 were fabricated. The batteries differed only in the composition of the cathode-active material employed. Specifically, the four batteries (numbered 1 to 4 respectively) employed the following active ingredient (s) in the cathode-active material:
Battery #1. Lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) with a weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide of 5: 5.
Battery #2. Lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) with a weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide of 3: 7.
Battery #3. Lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) with a weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide of 7: 3.
Battery #4. Lithium manganese iron phosphate (LMFP) .
Batteries #1 to 3 have a cathode-active material composition falling within the scope of the present disclosure. Battery #4 is included for the purposes of comparison with batteries #1 to 3.
The four different batteries were fabricated as follows:
Firstly, a mixture was provided of the respective active ingredient (s) for the cathode-active material, polyvinylidenefluoride (PVDF) as a binder and carbon as a conductive agent. The constituent elements of the mixture were mixed together in a non-aqueous solvent of N-methyl-2-pyrrolidine (NMP) to form a cathode-active slurry. The slurry was then coated onto an aluminium foil collector 1221, and then dried and rolled to produce the cathode 122.
Secondly, a mixture was provided of synthetic graphite, styrene-butadiene rubber (SBR) as a binder and carboxylmethyl cellulose as a stabiliser. These constituent elements were mixed together in water to produce an anode-active slurry. The synthetic graphite formed the active ingredient for the anode-active slurry. The slurry was then coated onto a copper foil collector 1211, and then dried and rolled to produce the anode 121.
The anode and cathode were placed in an electrolyte, in which the electrolyte was made by dissolving LiPF₆ in a non-aqueous organic solvent. A separator formed of polyethylene was located between the anode and cathode.
All of the batteries were charged for 0.1 hours at temperatures of 25 degrees Celsius or 40 degrees Celsius under conditions of 1.6 Amps /3.65 Volts of constant current and constant voltage, and then discharged under conditions of 10 to 20 C of pulse current and 2.55 V as a lower limit voltage until a total of 570 mWh discharge energy was reached. ‘C’ is a multiplier for the charge or discharge rate of the battery; a rate of 1 C equates to a battery being charged from 0 to 100%in one hour, and a rate of 2 C achieves the same level of charging in half the time, i.e. 30 minutes. The charge/discharge cycle outlined above was repeated over several thousand cycles and the capacity of the battery determined.
Figure 7 illustrates the variation in capacity with increasing number of charge cycles for each of batteries #1 to 4, with charging and discharging was performed at 25 degrees Celsius. As can be seen in Figure 7, those batteries (#1 to 3) employing a cathode-active material including a mixture of lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) as the active ingredients of the cathode-active material were seen to have a superior cycle life compared to the battery (#4) in which the cathode-active material has only lithium manganese iron phosphate as the active ingredient. So, the degradation in battery capacity with increasing number of charge cycles is slower when using a mixture of lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) compared to when using lithium manganese iron phosphate (LMFP) alone as the active ingredient for the cathode-active material. The performance improvements are particularly marked for the batteries having a cathode-active material in which the weight ratios of lithium manganese iron phosphate (LMFP) to lithium nickel manganese cobalt oxide (NMC) are 5: 5 and 3: 7 (Batteries #1 and 2) .
Figure 8 corresponds to Figure 7, but with charging and discharging of the batteries performed at a temperature of 40 degrees Celsius. Figure 8 again shows that the use of a cathode-active material including a mixture of lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) as the active ingredients of the cathode-active material provides an improved cycle life compared to batteries in which the cathode-active material has only lithium manganese iron phosphate (LMFP) as the active ingredient. So again, the degradation in battery capacity with increasing number of charge cycles is slower when using a mixture of lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) compared to when using lithium manganese iron phosphate (LMFP) alone as the active ingredient for the cathode-active material.
Figures 7 and 8 relate to a specific example in which the cathode-active material comprises lithium manganese iron phosphate (LMFP) and lithium nickel manganese cobalt oxide (NMC) as the active ingredients of the cathode-active material. However, as noted in the general description, lithium manganese iron phosphate is an evolution of lithium iron phosphate and has similar physical properties. Therefore, it will be appreciated that in other embodiments, lithium iron phosphate may be used in place of or in combination with lithium manganese iron phosphate. Further, lithium nickel cobalt aluminium oxide (NCA) or lithium cobalt oxide (LCO) may be used in place of lithium nickel manganese cobalt oxide (NMC) .
For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term “about” . Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number “A” is understood as “A” ± 10%of “A” . Within this context, a number “A” may be considered to include numerical values that are within general standard error for the measurement of the property that the number “A” modifies. The number “A” , in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which “A” deviates does not materially affect the basic and novel characteristic (s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

An aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:

a lithium-ion battery;

wherein the battery comprises a cathode, the cathode comprising a cathode-active material;

the cathode-active material comprising:

at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof; and

at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof.
An aerosol-generating system according to claim 1, wherein the cathode-active material comprises lithium manganese iron phosphate and lithium nickel manganese cobalt oxide.
An aerosol-generating system according to claim 2, wherein the weight ratio of lithium manganese iron phosphate to lithium nickel manganese cobalt oxide in the cathode-active material lies within a range of between 1: 9 and 9: 1, or between 3: 7 and 7: 3, or between 3: 7 and 5: 5.
An aerosol-generating system according to any one of claims 1 to 3, wherein the cathode-active material comprises lithium manganese iron phosphate as LiMn_iFe_1-iPO₄, wherein i lies within a range of between 0 and 1.
An aerosol-generating system according to claim 4, wherein i lies within a range of between 0.5 and 0.7.
An aerosol-generating system according to either one of claim 4 or claim 5, wherein the cathode-active material further comprises lithium nickel manganese cobalt oxide as LiNi_pCo_qMn_rO₂, wherein p lies within a range of between 0.4 and 0.6, q lies within a range of between 0.1 and 0.3 and r lies within a range of between 0.2 and 0.4, wherein p + q + r = 1.
An aerosol-generating system according to claim 6, wherein p has a value of 0.5, q has a value of 0.2 and r has a value of 0.3.
An aerosol-generating system according to any one of claims 1 to 7, wherein the cathode-active material further comprises a solvent, a binder, a conductive agent and a stabiliser.
An aerosol-generating system according to any one of claims 1 to 8, comprising an anode-active material comprising graphite, carbon, silicon, or a combination thereof.
An aerosol-generating system according to any one of claims 1 to 9, wherein the system comprises at least one of an aerosol-generating device and a charger for charging a power source of an aerosol-generating device.
An aerosol-generating system according to claim 10, wherein the battery forms part of the aerosol-generating device.
An aerosol-generating system according to any one of the preceding claims, the system further comprising an aerosol-generating article comprising the aerosol-forming substrate.
An aerosol-generating system according to claim 10, wherein the battery forms part of the charger.
A method of operating an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, the aerosol-generating system comprising:

a lithium-ion battery;

wherein the battery comprises a cathode, the cathode comprising a cathode-active material;

the cathode-active material comprising:

at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof; and

at least one compound selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof;

the method comprising connecting the aerosol-forming substrate to the aerosol-generating system, and using the aerosol-generating system to generate aerosol from the aerosol-generating substrate.
Use of a lithium-ion battery in an aerosol-generating system for generating an inhalable aerosol from an aerosol-forming substrate, wherein the battery comprises a cathode, the cathode comprising a cathode-active material;

the cathode-active material comprising:

at least one compound selected from a first group of compounds, the first group of compounds comprising lithium manganese iron phosphate, lithium iron phosphate, or a combination thereof; and

at least one member selected from a second group of compounds, the second group of compounds comprising lithium nickel manganese cobalt oxide, lithium nickel cobalt aluminium oxide, lithium cobalt oxide, or a combination thereof.