CN215936305U

CN215936305U - Porous carbon heating element, electric heating atomizing core and electron cigarette

Info

Publication number: CN215936305U
Application number: CN202122457640.3U
Authority: CN
Inventors: 于杰; 林梓家; 李振伟; 苑甫; 王恩哥
Original assignee: Songshan Lake Materials Laboratory
Current assignee: Songshan Lake Materials Laboratory
Priority date: 2021-10-12
Filing date: 2021-10-12
Publication date: 2022-03-04
Anticipated expiration: 2031-10-12

Abstract

The application relates to a porous carbon heat-generating body, electric heating atomizing core and electron cigarette belongs to electron cigarette technical field. The porous carbon heating body is internally provided with a plurality of through holes, the hole wall of each through hole is provided with a plurality of blind holes, and the aperture of each through hole is larger than that of each blind hole. The aperture of the through hole is not larger than the micron level, and the aperture of the blind hole is in the nanometer level. Through the cooperation of the through hole with the aperture not larger than the micron-sized through hole and the blind hole with the aperture being the nanometer-sized through hole, the heating body can have certain liquid locking capacity, so that oil leakage is prevented, and dry burning caused by insufficient tobacco tar infiltration is prevented. Meanwhile, the heating body is made of porous carbon, the heating body is wholly homogenized to heat, the temperature uniformity is improved, and the material cracking caused by local overheating and thermal shock is avoided; and the carbon material has high infrared radiance (more than 90%), high penetrability of radiant heat and high electrothermal conversion efficiency (more than 90%), is more energy-saving and efficient, and is beneficial to the miniaturization of equipment.

Description

Porous carbon heating element, electric heating atomizing core and electron cigarette

Technical Field

The application relates to the technical field of electronic cigarettes, and in particular relates to a porous carbon heating body, an electric heating atomization core and an electronic cigarette.

Background

With the generalization of the global smoking control trend, new tobacco products are becoming important development directions of the tobacco industry due to the advantage of reducing harmful ingredients, and electronic cigarettes therein have become one of the hot spots of the new tobacco products in the world.

The core component of the electronic cigarette is an atomizing core, and the atomizing core has undergone three generations of technological evolution after decades of development. The first generation technology is that a glass fiber rope is wrapped with a heating wire, and the problems of easy generation of floccules, easy powder falling and uneven heating are eliminated. The second generation technology is resistance wire cotton core, which has the advantages of large oil storage capacity, good oil guiding performance and dense smoke amount, but has obvious defects, such as no high temperature resistance of the cotton core, easy dry burning, uneven heating of tobacco oil by resistance wires, easy generation of scorched smell, loose cotton core structure, poor liquid locking capacity, easy oil leakage and large atomized molecular particles. The third generation technology is a ceramic atomizing core, and has the advantages of small atomizing particles, fine taste, good consistency and difficult occurrence of oil leakage and scorching.

At present, a ceramic atomizing core has a tendency of gradually replacing a resistance wire cotton core, but the ceramic atomizing core still has defects, the preparation method of the ceramic atomizing core is that an alloy heating wire, a heating sheet and a metal net are embedded in or on the surface of porous ceramic, or a heating circuit is printed on the surface of the porous ceramic, the volume ratio of the alloy wire or the metal printed circuit is usually very small, a ceramic material serving as a main body part of the atomizing core does not generate heat, and tobacco tar is heated by heat conduction of a resistor, so that obvious temperature nonuniformity exists, when the suction amount is large and the tobacco tar is not sufficiently soaked, the local overheating of the metal wire can also occur to generate scorched smell, and the temperature of a ceramic substrate is lower, and the atomizing effect is insufficient; and because the thermal expansion coefficients of metal and ceramic are not consistent, cracking can occur under long-time thermal shock.

SUMMERY OF THE UTILITY MODEL

To prior art's not enough, the purpose of this application embodiment is including providing a porous carbon heat-generating body, electrical heating atomizing core and electron cigarette, uses the carbon material as the heat-generating body of electrical heating atomizing core in the electron cigarette, and heating effect is good.

First aspect, this application embodiment provides a porous carbon heat-generating body, and the inside of porous carbon heat-generating body has a plurality of through-holes, is provided with a plurality of blind holes on the pore wall of every through-hole, and the aperture of through-hole is greater than the aperture of blind hole. The aperture of the through hole is not larger than the micron level, and the aperture of the blind hole is in the nanometer level.

In this application, a plurality of apertures are not more than the setting of the through-hole of micron order, can make the oil absorption effect of heat-generating body better to this through-hole cooperates with the blind hole that the aperture is the nanometer level, can make the heat-generating body still have certain lock liquid ability, has both prevented the oil leak and has prevented that the tobacco tar soaks not enough dry combustion method of appearing. Meanwhile, the heating body is made of porous carbon, the heating body is wholly homogenized to heat, the temperature uniformity is improved, and the material cracking caused by local overheating and thermal shock is avoided; and the carbon material has high infrared radiance (more than 90%), high penetrability of radiant heat and high electrothermal conversion efficiency (more than 90%), is more energy-saving and efficient, and is beneficial to the miniaturization of equipment.

In some embodiments of the present application, the aperture of the through hole is 200-1000nm, the aperture of the blind hole is 10-100nm, and the depth of the blind hole is 10-100 nm. The oil absorption capacity of the porous carbon heating body can be stronger, and the liquid locking capacity is better.

In some embodiments of the present application, the through-holes comprise tortuous through-holes, a plurality of which are through-going. The tortuous through holes are matched with the blind holes to form a tortuous porous structure and a multistage pore structure with alternately distributed big holes and small holes, so that the structure enhances the capillary force of the material for absorbing oil and improves the oil absorption speed and the liquid locking capacity.

In some embodiments of the present application, the porosity of the porous carbon heat-generating body is 60% to 90%. The porous carbon heating body has high porosity, large specific surface area, large oil absorption and small atomized particles, and ensures fine mouthfeel and dense smoke amount.

In a second aspect, the embodiment of the present application provides an electrically heated atomizing core, which includes two electrodes and the above-mentioned porous carbon heating element, and the two electrodes are fixed to the two ends of the porous carbon heating element respectively.

Use above-mentioned porous carbon heat-generating body in the electrical heating atomizing core, cooperate through the through-hole and the blind hole in different apertures, can make the oil absorption effect of heat-generating body better to this through-hole cooperates with the blind hole that the aperture is nanometer, can make the heat-generating body still have certain lock liquid ability, has both prevented the oil leak and has prevented that the dry combustion method from appearing in the tobacco tar infiltration inadequately. Simultaneously, porous carbon homogeneity heating atomizing core is whole homogeneity heating, and oil absorption position and atomizing position can all be regarded as to whole atomizing core, and temperature homogeneity is high, does not have local overheat phenomenon, can realize the synchronous heating atomizing when the material oil absorption, and the atomizing is fast, and smog volume is big and the suction is controllable, and simultaneously, the stability of porous carbon homogeneity heating atomizing core is good, and thermal shock resistance can be good, and inefficacy behaviors such as fracture are difficult for appearing.

In some embodiments of the present application, the electrode and the porous carbon heating element are fixed by welding, riveting, conductive paste layer, elastic clamping or pressure clamping. The fixing effect between the electrode and the porous carbon heating body can be better.

In some embodiments of the present application, the electrode is one of a graphite electrode, a nickel electrode, a copper electrode, an iron electrode, an aluminum electrode, a silver electrode, and a gold electrode.

In some embodiments of the present application, the electrode is a porous metal electrode. The electrode can not block the porous carbon heat-generating body oil absorption at the electrode junction, and the smog granule after the atomizing can follow the electrode junction and escape, has both increased the oil absorption face of porous carbon heat-generating body and has increased the atomizing face, has improved the utilization ratio of bulk material.

In some embodiments of the present application, the electrode is one of porous nickel, porous copper, porous iron, porous aluminum, and porous silver.

In some embodiments of the present application, the porous carbon heating element is one of a rectangular parallelepiped, a polygonal prism, and a prism.

In some embodiments of the application, the outer contour dimension of the porous carbon heating element is 3-15mm in length, 1-5mm in width and 0.5-2mm in height; the distance between the two electrodes is 3-15 mm. Can make the atomizing core generate heat evenly, avoid resistance too big or undersize.

In some embodiments of the present application, the porous carbon heating element includes a heating atomization portion and a liquid absorption and conduction portion which are connected to each other, and the electrode is fixed to a joint of the heating atomization portion and the liquid absorption and conduction portion. The liquid absorption portion and the atomization portion are both made of porous carbon materials, so that the oil absorption and guide effect of the atomization core is better, and the atomization core can be well atomized.

In some embodiments of the present application, at least one surface of the porous carbon heat-generating body is an oil absorbing surface. The liquid absorption effect of the electric heating atomization core can be better by penetrating through the surface of the porous carbon heating body.

In some embodiments of the present application, the electrically heated atomizing core further comprises two electrical conductors, one electrical conductor connecting each electrode. The atomizing core can be conveniently connected with an external power supply.

In a third aspect, the present application provides an electronic cigarette, which includes the above electrically heated atomizing core.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic structural diagram of an electrically heated atomizing core provided in an embodiment of the present application;

FIG. 2 is a partial cross-sectional view of an electrically heated atomizing core provided in accordance with an embodiment of the present application;

FIG. 3 is a scanning electron microscope photomicrograph of 10K times of the porous carbon heating element provided in example 1 of the present application;

FIG. 4 is a scanning electron micrograph of a porous carbon heating element taken at 40K magnification according to example 1 of the present application.

Icon: 110-electrodes; 120-a current conductor; 130-porous carbon heating element; 131-liquid suction and liquid guide part; 132-heating the atomizer.

Detailed Description

In the prior art, the ceramic in the ceramic atomizing core does not generate heat, the tobacco tar is heated by heating through the metal resistor in the ceramic atomizing core, so that obvious temperature nonuniformity exists, when the suction volume is large, and the tobacco tar is not infiltrated sufficiently, the local overheating of the metal wire can also occur to generate scorched smell, and the ceramic matrix has low temperature and insufficient atomizing effect. And because the thermal expansion coefficients of metal and ceramic are not consistent, cracking can occur under long-time thermal shock.

The embodiment of the application provides a new electric heating atomizing core, and the new heat-generating body is used to the new electric heating atomizing core, can improve some problems of ceramic atomizing core. In order to make the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the present application are described below clearly and completely.

FIG. 1 is a schematic structural diagram of an electrically heated atomizing core provided in an embodiment of the present application; fig. 2 is a partial cross-sectional view of an electrically heated atomizing core provided in an embodiment of the present application. Referring to fig. 1 and fig. 2, the electrically heated atomizing core includes two electrodes 110 and a porous carbon heating element 130, and the two electrodes 110 are respectively fixed at two ends of the porous carbon heating element 130. Wherein, the inside of porous carbon heat-generating body 130 has a plurality of through-holes, is provided with a plurality of blind holes on the pore wall of every through-hole, and the aperture of through-hole is greater than the aperture of blind hole. The aperture of the through hole is not larger than the micron level, and the aperture of the blind hole is in the nanometer level.

The setting that a plurality of apertures are not more than the through-hole of micron order can make the oil absorption effect of heat-generating body better to this through-hole is the blind hole cooperation of nanometer with the aperture, can make the heat-generating body still have certain lock liquid ability, has both prevented the oil leak and has prevented that the tobacco tar soaks not enough dry combustion method that appears. Meanwhile, the heating body is made of porous carbon, the heating body is wholly homogenized to heat, the temperature uniformity is improved, and the material cracking caused by local overheating and thermal shock is avoided; and the carbon material has high infrared radiance (more than 90%), high penetrability of radiant heat and high electrothermal conversion efficiency (more than 90%), is more energy-saving and efficient, and is beneficial to the miniaturization of equipment.

In order to ensure that the oil absorption and guiding effects of the porous carbon heating element 130 are better, the oil can be better locked, and the oil leakage phenomenon can be avoided. The aperture of the through hole is 200-1000nm, the aperture of the blind hole is 10-100nm, and the depth of the blind hole is 10-100 nm.

It should be noted that: the number of the through holes is multiple, the apertures of the through holes are not limited to be consistent, the apertures of the through holes can be the same or different, and the aperture of the blind hole is not larger than the micron order; and the aperture of the same through hole may be different at different positions, which is not limited in the present application.

The number of the blind holes is multiple, the apertures of the blind holes are not limited to be consistent, the apertures of the blind holes can be the same or different, and the apertures of the blind holes can reach the nanometer level; the depths of the blind holes are not limited to be consistent, the depths of the blind holes can be the same or different, and the depths of the blind holes can reach the nanometer level.

Optionally, the through-holes comprise a meandering through-hole, through which a plurality of meandering through-holes pass. The tortuous through holes are matched with the blind holes to form a tortuous porous structure and a multistage pore structure with alternately distributed big holes and small holes, so that the structure enhances the capillary force of the material for absorbing oil and improves the oil absorption speed and the liquid locking capacity.

Wherein, all the through holes can be zigzag through holes, and part of the through holes can also be zigzag through holes; all through holes can be communicated with each other, and also partial through holes can be communicated with each other, and the application is not limited.

Optionally, the porosity of the porous carbon heat-generating body 130 is 60% to 90%. The porous carbon heating body 130 has high porosity, large specific surface area, large oil absorption and small atomized particles, and ensures fine mouthfeel and dense smoke amount.

In this application, the porous carbon heating element 130 is one of a rectangular parallelepiped, a polygonal prism, and a prism table. The heating element may have other shapes. After the porous carbon heating element 130 is matched with the two electrodes 110, the obtained electrically heated atomizing core can be one of a cuboid, a polygonal prism and a prismatic table.

Optionally, the outer contour dimension of the porous carbon heating element is 3-15mm in length, 1-5mm in width and 0.5-2mm in height; the distance between the two electrodes is 3-15 mm. Can make the atomizing core generate heat evenly, avoid resistance too big or undersize. Although the length, width and height are described here, the porous carbon heating element is not limited to a rectangular parallelepiped structure, and only the outline dimensions thereof will be described roughly.

With reference to fig. 1 and fig. 2, the electrodes 110 are block-shaped, and the two electrodes 110 are respectively disposed at two ends of the porous carbon heating element 130 and contact with the basic surface of the porous carbon heating element 130. The electrode 110 is a porous metal electrode 110. The electrode 110 can not block the porous carbon heating element 130 at the joint of the electrode 110 from absorbing oil, and atomized smoke particles can escape from the joint of the electrode 110, so that the oil absorption surface and the atomization surface of the porous carbon heating element 130 are increased, and the utilization rate of the whole material is improved.

In the present application, the electrode may be one of a graphite electrode, a nickel electrode, a copper electrode, an iron electrode, an aluminum electrode, a silver electrode, and a gold electrode. Optionally, the electrode is a porous metal electrode 110, which is one of porous nickel, porous copper, porous iron, porous aluminum, porous silver.

In the present application, in order to improve the fixing effect between the electrode 110 and the porous carbon heating element 130, the electrode 110 and the porous carbon heating element 130 are fixed by the conductive paste layer. In other embodiments, the two ends of the porous carbon heating element 130 may be fixed by welding, riveting, elastic clamping or pressure clamping.

In the present application, a current conductor 120 (e.g., a current lead) may also be connected to the electrode 110 to provide current to an external power source. Optionally, the current conductor 120 is one of silver, copper, iron, aluminum, nickel, and zinc. The current conductor 120 is fixed to the electrode 110 by welding. In other embodiments, the electrode 110 and the current conductor 120 may be connected by riveting or pressure connection.

The application provides a porous carbon heat-generating body 130 includes liquid portion 131 and the heating atomization portion 132 of imbibition that interconnect, electrode 110 is fixed in the junction of liquid portion 131 and the heating atomization portion 132 of imbibition, can realize whole homogeneity heating, whole atomizing core all can regard as oil absorption position and atomizing position, temperature uniformity is high, local overheat phenomenon does not exist, synchronous heating atomization can be realized to the material when oil absorption, the atomizing speed is fast, the smog volume is big and the suction is controllable, and simultaneously, the stability of porous carbon homogeneity heating atomizing core is good, thermal shock resistance is good, the inefficacy behaviors such as fracture are difficult to appear.

Optionally, at least one surface of the porous carbon heat-generating body 130 is an oil absorption surface, and the liquid absorption effect of the electrically heated atomizing core can be better by penetrating the surface of the porous carbon heat-generating body.

In another embodiment, the heating and atomizing unit 132 may be a porous heating element, the liquid-absorbing and liquid-guiding unit 131 may be a porous ceramic material, and the porous ceramic and the porous carbon may be bonded or embedded to each other.

Above-mentioned electrical heating atomizing core is used for preparing the electron cigarette, and the heating method of electrical heating atomizing core is carbon material infrared radiation heating, and infrared radiation's penetrability is high, and is high to efficiency and the homogeneity of tobacco tar heating, and is more energy-conserving, high-efficient, is favorable to the miniaturization of atomization plant.

Having introduced the electrically heated atomizing core, a method of making the electrically heated atomizing core is described as follows, comprising:

s110, preparing the porous carbon heating element 130

And S111, forming a porous carbon substrate with a plurality of through holes inside. The forming method can be as follows: any one of a carbon fiber needling forming method, a polymer pore-forming carbonization forming method, a carbon fiber and polymer mixed pore-forming carbonization forming method and a porous template vapor deposition forming method.

Optionally, the carbon fiber needle punching method comprises: soaking carbon fibers in a polymer solution, filtering, placing in needling equipment for needle punching forming, or soaking the carbon fibers in the polymer solution after needle punching forming, draining, and then performing heating treatment; wherein the conditions of the heat treatment are as follows: under the protection of inert gas, the temperature is 500 ℃ and 1500 ℃.

Wherein, the carbon fiber is one or two of chopped carbon fiber and continuous carbon fiber. The polymer is one or more of polyacrylonitrile, polyimide, polycarbonate, polyaryl acetylene, phenolic resin, epoxy resin and asphalt.

For example: soaking carbon fibers in a polyvinyl alcohol aqueous solution, fully stirring and uniformly dispersing, filtering, placing in needling equipment, carrying out needling treatment to obtain carbon fiber blocky solids (or placing the carbon fibers in the needling equipment, carrying out needling treatment, then soaking in the polyvinyl alcohol aqueous solution, draining to obtain carbon fiber blocky solids), placing in an oven for drying, removing a solvent, placing the obtained solids in a heating furnace, introducing nitrogen as a protective gas, heating to 1200 and 1400 ℃, carrying out heat treatment, and keeping the temperature for 60-120min to obtain the porous carbon matrix with the zigzag through hole structure.

Alternatively, the pore-forming carbonization molding method for the polymer comprises the following steps: drying, curing and forming the solution with the polymer and the pore-forming agent, and then carrying out heating treatment; wherein the conditions of the heat treatment are as follows: under the protection of inert gas, the temperature is 500-1500 ℃, and the mass ratio of the polymer to the pore-forming agent is (95:5) - (60: 40).

Wherein, the polymer in the polymer pore-forming carbonization forming method is one or more of polyacrylonitrile, polyimide, polycarbonate, polyaryl acetylene, phenolic resin, epoxy resin and asphalt; the pore-forming agent is one or more of ammonium bicarbonate, ammonium nitrate, starch, glucose, polyvinylpyrrolidone and polyvinyl butyral.

For example: dissolving a polymer in a solvent, adding a pore-forming agent, mixing, uniformly mixing to obtain a mixed solution (the polymer and the pore-forming agent are simultaneously dispersed in the same solution to obtain the mixed solution), placing the mixed solution in a mold, then placing the mold in an oven, treating at the temperature of 300-400 ℃, and keeping the temperature for more than 30min (for example, 60-120min), wherein in the heat preservation process, the solvent in the mold is volatilized, and the pore-forming agent is decomposed to form a polymer solid with a porous structure. And (3) putting the polymer solid in a heating furnace, introducing nitrogen as protective gas, heating to 1200-1400 ℃ for carbonization, and keeping the temperature for 60-120min to obtain the porous carbon matrix.

Optionally, the pore-forming carbonization forming method for mixing carbon fiber with polymer comprises the following steps: dispersing carbon fibers, a polymer and a pore-forming agent in the same solution, and performing heating treatment after molding; wherein the conditions of the heat treatment are as follows: under the protection of inert gas, the temperature is 500-1500 ℃, and the mass ratio of the carbon fiber, the polymer and the pore-forming agent is (80-40) to (20-5) in sequence.

The carbon fiber in the pore-forming carbonization molding method by mixing the carbon fiber and the polymer is one or two of chopped carbon fiber and continuous carbon fiber. The polymer is one or more of polyacrylonitrile, polyimide, polycarbonate, polyaryl acetylene, phenolic resin, epoxy resin and asphalt; the pore-forming agent is one or more of ammonium bicarbonate, ammonium nitrate, starch, glucose, polyvinylpyrrolidone and polyvinyl butyral.

For example, carbon fibers are placed in a solvent for dispersion, polymer powder is added, stirring and dissolving are carried out at 80-100 ℃ to obtain a mixed solution A, a pore-forming agent is dissolved in the solvent, stirring and dissolving are carried out at normal temperature to obtain a solution B, A, B liquid is mixed and uniformly stirred and then poured into a rectangular mold, the rectangular mold is placed in an oven for drying, after the solvent is removed, the obtained solid is placed in a heating furnace, nitrogen is introduced as protective gas, the temperature is increased to 1200-1400 ℃ for heat treatment, and the heat preservation time is 60-120min, so that the porous carbon matrix with the zigzag through hole structure is obtained.

Optionally, the porous template vapor deposition modeling method comprises: carrying out vapor deposition by taking porous metal as a template and hydrocarbon gas as a carbon source, and then removing the porous metal template through acid washing; wherein the temperature of vapor deposition is 800-1500 ℃, and the time is 1-8 h. The porous metal is porous nickel or porous copper, and the hydrocarbon gas is methane or acetylene.

For example: and (3) taking foamed nickel as a template, placing the foamed nickel in a chemical vapor deposition furnace, heating to 1000-1200 ℃, introducing acetylene for carbon deposition, cooling after 60-120min, cooling to room temperature, soaking the obtained solid in hydrochloric acid, and removing the foamed nickel template to obtain the porous carbon substrate with the bent through hole structure.

And S112, forming a plurality of blind holes on the wall of the through hole. The forming method can be as follows: chemical vapor deposition or gas activation. The chemical vapor deposition method is to prepare the blind holes by an additive method, the gas activation method is to prepare the blind holes by a material reduction method, and the blind holes can be prepared into nano-scale blind holes, so that a good oil locking effect is realized, and the oil leakage phenomenon is avoided to a certain extent.

In one embodiment, a chemical vapor deposition process comprises: placing the porous carbon matrix in a heating furnace, introducing inert gas (such as argon) as protective gas, heating to 1000-1500 ℃, introducing hydrogen and methane, and treating for 1-8h to grow graphene nano sheets on the pore walls of the porous carbon matrix, wherein the graphene nano sheets are lapped to form blind holes. Graphene nanosheets uniformly grow on the surface of the hole wall of the porous carbon substrate, and the graphene nanosheets are mutually overlapped to form a blind hole structure so as to lock oil.

In another embodiment, a gas activation process comprises: placing the porous carbon matrix in a heating furnace, introducing inert gas (such as argon) as protective gas, heating to 1000-1500 ℃, introducing water vapor and/or carbon dioxide, and treating for 1-3h, so that part of carbon on the pore wall surface of the porous carbon matrix reacts with the water vapor or the carbon dioxide to be converted into gas, thereby forming blind pores on the surface of the porous carbon matrix.

S120, preparing an electric heating atomization core

S121, the electrode 110 is fixed to the porous carbon heating element 130. Alternatively, the porous metal electrodes 110 are fixed to both sides of the porous carbon heating element 130 by conductive pastes, respectively, the conductive pastes are coated on both ends of the porous carbon heating element 130, and then the electrodes 110 are fixed. The conductive paste is a high-temperature resistant conductive silver paste, such as one of sintered silver paste, gold paste, platinum paste and graphene paste.

The porous metal electrode 110 is used to increase the liquid-absorbing and liquid-guiding part 131 and the atomization surface of the porous carbon heating element 130, thereby improving the utilization rate of the whole material.

S122, the current conductor 120 is fixed to the electrode 110. The current conductor 120 is fixed to the porous metal electrode 110 by welding. Wherein, the welding solder can be selected from high temperature resistant solder, such as silver brazing solder and zinc-aluminum-silver-copper alloy solder. The purpose of this step is to extend the metal electrode 110 to connect with the positive and negative electrodes of the battery, so as to supply power to the battery.

The application provides an effect of electric heating atomizing core as follows:

(1) the setting that a plurality of apertures are not more than the through-hole of micron order can make porous carbon heat-generating body 130's oil absorption effect better to this through-hole cooperates with the blind hole that the aperture is the nanometer level, can make porous carbon heat-generating body 130 still have certain lock liquid ability, has both prevented the oil leak and has prevented that the tobacco tar soaks not enough dry combustion method of appearing.

(2) The structure enhances the capillary force of the material for oil absorption, and improves the oil absorption speed and the liquid locking capacity.

(3) Porous metal electrode 110 is connected with porous carbon heat-generating body 130, can not block porous carbon heat-generating body 130 at the electrode 110 junction and inhale the oil, and the smog granule after the atomizing can be followed electrode 110 junction and escaped, has both increased porous carbon heat-generating body 130's the face of inhaling oil and has increased the atomizing face, has improved the utilization ratio of bulk material.

(4) The porous carbon heating body is whole homogeneity heating, and oil absorption position and atomizing position all can be regarded as to whole heat-generating body, and temperature homogeneity is high, does not have local overheat phenomenon, can realize the synchro-heating atomizing when the material oil absorption, and the atomizing is fast, and smog volume is big and the suction is controllable, and simultaneously, porous carbon heating body 130's stability is good, and thermal shock resistance can be good, and inefficacy behaviors such as fracture are difficult for appearing.

(5) The heating body is made of porous carbon, the heating body is wholly homogenized to heat, the temperature uniformity is improved, and the material cracking caused by local overheating and thermal shock is avoided; and the carbon material has high infrared radiance (more than 90%), high penetrability of radiant heat, high electrothermal conversion efficiency (more than 90%), high efficiency and uniformity of heating tobacco tar, more energy conservation and high efficiency, and is beneficial to the miniaturization of atomization equipment.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

The embodiment provides a preparation method of an electric heating atomization core, which comprises the following steps:

(1) placing short carbon fibers with the length of about 5cm and the diameter of about 5 microns in a dimethylformamide solvent for dispersion, adding polyacrylonitrile powder, stirring and dissolving at 80 ℃ to obtain a mixed solution A, dissolving starch in a dimethyl sulfoxide solvent, stirring and dissolving at normal temperature to obtain a solution B, wherein the mass ratio of the carbon fibers to the polyacrylonitrile to the starch is 50:30:20, mixing and uniformly stirring A, B liquid, pouring the mixture into a cuboid mold, placing the cuboid mold in an oven for drying, removing the solvent, placing the obtained solid in a heating furnace, introducing nitrogen as protective gas, heating to 1200 ℃ for heat treatment, and keeping the temperature for 60min to obtain the porous carbon matrix with the zigzag through hole structure.

(2) And continuously introducing hydrogen and methane into the heating furnace to perform chemical vapor deposition, wherein the flow ratio of the hydrogen to the methane is 10:1, and the heat preservation time is 6 hours, so that vertical graphene nanosheets are uniformly distributed on the surface of the porous carbon substrate, and the graphene nanosheets are mutually overlapped to form a micro blind hole structure, thereby obtaining the porous carbon heating body.

(3) Cutting the porous carbon heating body into a cuboid with the size of 8cm multiplied by 6cm multiplied by 5cm, adhering two porous nickel electrode plates with the size of 6cm multiplied by 5cm on two surfaces of the porous carbon heating body by adopting sintered conductive silver paste, and sintering at 500 ℃; and finally, welding the electrified conductor on the porous nickel electrode by adopting silver brazing solder to obtain the electrically heated atomizing core.

FIG. 3 is a scanning electron microscope photomicrograph of 10K times of the porous carbon heating element provided in the example of the present application; FIG. 4 is a scanning electron microscope photomicrograph of the porous carbon heating element at a magnification of 40K, which is provided in the examples of the present application. As can be seen from fig. 3 and 4, the surface of the porous carbon substrate is uniformly distributed with vertical graphene nano sheets, the graphene nano sheets are mutually overlapped to form a micro blind hole structure, and the size of the blind hole on the surface of the carbon fiber is about 50 nm.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating element provided by the embodiment is 226m²In terms of a/g, the porosity is 87%.

Example 2

Example 2 is a modification of example 1, and example 2 differs from example 1 in that: in the step (1), short carbon fibers with the length of about 5cm and the diameter of about 5 microns are soaked in a polyvinyl alcohol aqueous solution, fully stirred and uniformly dispersed, filtered and then placed in needling equipment for needling treatment to obtain carbon fiber blocky solids, the carbon fiber blocky solids are placed in an oven for drying, after a solvent is removed, the obtained solids are placed in a heating furnace, nitrogen is introduced as protective gas, the temperature is raised to 1200 ℃ for heat treatment, and the heat preservation time is 60min, so that the porous carbon matrix with the zigzag through hole structure is obtained.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating element provided by the embodiment is 180m²In terms of a/g, the porosity is 90%.

Example 3

Example 3 is a modification of example 1, and example 3 differs from example 1 in that: in the step (1), dissolving polyamic acid in a dimethylacetamide solvent, stirring until the solution is clear, adding ammonium bicarbonate, stirring at a high speed, uniformly mixing, pouring the obtained mixed solution into a cuboid mold, placing the cuboid mold in an oven, carrying out imidization at 350 ℃, keeping the temperature for 60min, and carrying out reaction along with solvent volatilization and ammonium bicarbonate decomposition to obtain a polyimide solid with a porous structure, wherein the mass ratio of polyamic acid to ammonium bicarbonate is 90: 10; and continuously placing the polyimide solid in a heating furnace, introducing nitrogen as protective gas, heating to 1200 ℃ for carbonization, and keeping the temperature for 60min to obtain the porous carbon matrix.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating element provided by the embodiment is 215m²In terms of a/g, the porosity is 78%.

Example 4

Example 4 is a modification of example 1, and example 4 differs from example 1 in that: in the step (1), foam nickel is used as a template, the foam nickel is placed in a chemical vapor deposition furnace, the temperature is raised to 1000 ℃, acetylene is introduced for carbon deposition, the temperature is reduced after 60min, the obtained solid is soaked in hydrochloric acid after being cooled to room temperature, and the foam nickel template is removed, so that the porous carbon substrate with the zigzag through hole structure is obtained.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating element provided by the embodiment is 160m²(ii)/g, porosity 70%.

Example 5

Example 5 is a modification of example 1, and example 5 differs from example 1 in that: in the step (2), water vapor and carbon dioxide gas are continuously introduced into the heating furnace to perform gas activation for 2 hours, so that part of carbon on the surface of the pore wall of the porous carbon substrate reacts with the water vapor or the carbon dioxide to be converted into gas, blind holes are formed on the surface of the porous carbon substrate, and the porous carbon heating element is obtained.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating element provided by the embodiment is 198m²In terms of a/g, the porosity is 75%.

Comparative example 1

A preparation method of an electrically heated atomizing core comprises the following steps:

(2) Cutting the porous carbon substrate into a cuboid with the size of 8cm multiplied by 6cm multiplied by 5cm, adhering two porous nickel electrode plates with the size of 6cm multiplied by 5cm on two surfaces of the porous carbon heating body by adopting sintered conductive silver paste, and sintering at 500 ℃; and finally, welding the electrified conductor on the porous nickel electrode by adopting silver brazing solder to obtain the electrically heated atomizing core.

Through the test of the nitrogen isothermal adsorption and desorption curve, the specific surface area of the porous carbon heating body provided by the comparative example is 50m²In terms of a/g, the porosity is 63%.

The embodiments described above are some, but not all embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Claims

1. A porous carbon heating body is characterized in that a plurality of through holes are formed in the porous carbon heating body, a plurality of blind holes are formed in the wall of each through hole, and the aperture of each through hole is larger than that of each blind hole; the aperture of the through hole is not larger than the micron-scale, and the aperture of the blind hole is in the nanometer scale.

2. A porous carbon heat-generating body as described in claim 1, characterized in that the aperture of said through hole is 200-1000nm, the aperture of said blind hole is 10-100nm, and the depth of said blind hole is 10-100 nm.

3. A porous carbon heat-generating body as described in claim 2, wherein said through-hole comprises a meandering through-hole through which a plurality of said meandering through-holes are penetrated.

4. A porous carbon heat-generating body as described in any one of claims 1 to 3, characterized in that the porosity of the porous carbon heat-generating body is 60% to 90%.

5. An electrically heated atomizing core characterized by comprising two electrodes and the porous carbon heat-generating body as recited in any one of claims 1 to 4, the two electrodes being fixed to both ends of the porous carbon heat-generating body, respectively.

6. The electrically heated atomizing core according to claim 5, wherein the electrode and the porous carbon heating element are fixed by welding, riveting, conductive paste layer, elastic clamping or pressure clamping.

7. The electrically heated atomizing core according to claim 5, wherein the electrode is one of a graphite electrode, a nickel electrode, a copper electrode, an iron electrode, an aluminum electrode, a silver electrode, and a gold electrode.

8. The electrically heated atomizing core according to claim 5, wherein the porous carbon heating element is one of a cuboid, a polygonal prism and a prismatic table, and the outer contour dimension of the porous carbon heating element is 3-15mm in length, 1-5mm in width and 0.5-2mm in height; the distance between the two electrodes is 3-15 mm.

9. The electrically heated atomizing core according to claim 5, wherein the porous carbon heat-generating body includes a heated atomizing part and a liquid-absorbing and liquid-guiding part which are connected to each other, and the electrode is fixed to a joint of the heated atomizing part and the liquid-absorbing and liquid-guiding part.

10. An electronic cigarette, comprising the electrically heated atomizing core of any one of claims 5 to 9.