WO2023011646A1 - 石墨烯膜及其制备方法 - Google Patents

石墨烯膜及其制备方法 Download PDF

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WO2023011646A1
WO2023011646A1 PCT/CN2022/110642 CN2022110642W WO2023011646A1 WO 2023011646 A1 WO2023011646 A1 WO 2023011646A1 CN 2022110642 W CN2022110642 W CN 2022110642W WO 2023011646 A1 WO2023011646 A1 WO 2023011646A1
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layer
resistance
furnace
crucible
particles
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PCT/CN2022/110642
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English (en)
French (fr)
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王乾龙
张艳
朱义为
江海
钟起权
姜华文
康南波
姜佳林
廖祥
林锦盛
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深圳市深瑞墨烯科技有限公司
Oppo广东移动通信有限公司
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Publication of WO2023011646A1 publication Critical patent/WO2023011646A1/zh

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    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
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Definitions

  • the present disclosure relates to the technical field of graphite materials, in particular, to a graphene film and a preparation method thereof.
  • Graphene film has attracted more and more attention from the market because of its excellent thermal and electrical conductivity. Especially with the rapid development of the electronics industry, electronic products are increasingly highly integrated, causing heat dissipation of electrical equipment to become an urgent problem to be solved, and the reliability of electrical equipment will decline with the accumulation of heat. Therefore, in view of the excellent thermal and electrical properties of graphene, it is expected to be developed into a mainstream functional electronic material in the future.
  • the batch preparation of graphene films uses graphene oxide or graphite oxide as raw materials, and the graphene oxide films are formed by suction filtration, dip coating, spin coating, spray coating, evaporation and coating, and then obtained after graphitization.
  • the most commonly used graphitization method is to use an electromagnetic induction graphitization furnace, which is also the most commonly used graphitization method for commercial synthetic graphite heat-conducting films.
  • the conventional electromagnetic induction graphitization furnace has problems such as short service life, mediocre performance, and complicated installation of the furnace insulation material, which cause the graphitization temperature and holding time to drop sharply with the increase in the number of uses.
  • the electromagnetic induction graphitization furnace can only be operated within the range of 2600-2900°C, which makes it unable to meet the high temperature heat treatment temperature required for the reduction of graphene oxide film; on the other hand, due to the short life of the electromagnetic induction graphitization furnace itself, the performance declines rapidly And other problems, also can't meet the preparation requirement of graphene film. And because the graphene film is obtained by carbonizing and graphitizing the graphene oxide film, a large number of oxygen-containing functional groups contained in the graphene oxide film will decompose as the temperature increases, resulting in electromagnetic induction graphitization of furnace materials such as graphite.
  • the present disclosure provides a kind of preparation method of graphene membrane, described method comprises the following steps:
  • the fluffy graphene film is compacted and densified to obtain a graphene film.
  • the reduced graphene oxide film is placed in a crucible in the Acheson graphitization furnace, and embedded resistance particles are laid between the crucibles in the Acheson graphitization furnace and on the surface of the crucible,
  • the resistance particles heat up to the graphitization temperature; the average particle diameter of the resistance particles ranges from 0 to 30mm, excluding 0mm.
  • the reduced graphene oxide film and graphite paper are laminated and then placed into the crucible in the Acheson graphitization furnace, and the crucibles in the Acheson graphitization furnace are laid Bury resistance heating particles, the resistance heating particles heat up to the graphitization temperature; the resistance heating particles include calcined coke with different particle sizes, the average particle size of the calcined coke ranges from 0 to 30mm, and does not include 0mm.
  • a layer of resistance particles and a protective layer are laid sequentially from the upper layer to the lower layer; A layer of resistive particles is laid.
  • the resistive particle layer in the chamber of the Acheson graphitization furnace located below the crucible includes at least two layers, and the average particle size of each layer of the resistive particle layer decreases layer by layer from the upper layer to the lower layer.
  • the resistive particle layer in the chamber of the Acheson graphitization furnace above the crucible includes at least four layers, and the average particle size of each layer of the resistive particle layer decreases gradually from the lower layer to the upper layer.
  • the resistive particle layer in the furnace cavity of the Acheson graphitization furnace located below the crucible includes two layers, including layers of particles laid in sequence from the upper layer to the lower layer with an average particle size ranging from 8 mm to 30 mm and less than or equal to 2 mm. Resistive particle layer.
  • the resistive particle layer in the furnace cavity of the Acheson graphitization furnace above the crucible includes four layers, including the average particle diameters of the particles laid sequentially from the lower layer to the upper layer in the range of 8 mm to 30 mm, 5 mm to 10 mm, 2mm ⁇ 4mm and less than or equal to 2mm resistance particle layer.
  • the resistor particles include at least one of calcined petroleum coke, green petroleum coke and carbon black.
  • the volatile components in the reduced graphene oxide film are less than 10wt%.
  • the graphitization temperature ranges from 3000°C to 3200°C.
  • the heat treatment period in the high temperature heat treatment is 10 days to 30 days.
  • the temperature is raised to the graphitization temperature in stages.
  • the high temperature heat treatment includes:
  • the temperature of the Acheson graphitization furnace is raised to 1000°C-1400°C and kept for 5h-10h;
  • the temperature in the Acheson graphitization furnace is continuously raised to 2000°C-2100°C, and kept for 5h-10h;
  • the compaction pressure of the fluffy graphene film is 2MPa ⁇ 100MPa.
  • the method before the reduced graphene oxide film is put into the Acheson graphitization furnace, the method also includes;
  • the graphene oxide film is baked to obtain a reduced graphene oxide film.
  • the graphene oxide film is prepared from a slurry containing graphene oxide or graphite oxide.
  • the concentration of the slurry containing graphene oxide or graphite oxide is 1 mg/mL ⁇ 80 mg/mL.
  • the graphene oxide-containing slurry or the graphite oxide slurry is obtained by mixing in any of the following ways: ultrasonic, mechanical shear exfoliation, mechanical stirring and high-pressure homogenization.
  • the preparation process of the graphene oxide film includes any one of suction filtration process, dip coating process, spin coating process, spray coating process, evaporation process and coating process.
  • the baking temperature is 150°C-550°C.
  • the heating rate of the baking is 0.5°C/h-10°C/h.
  • the holding time of the baking is 5h-50h.
  • the present disclosure provides a graphene film prepared by the above-mentioned preparation method.
  • the thickness of the graphene film is 10 ⁇ m ⁇ 300 ⁇ m.
  • the density of the graphene film is 1.8g/cm 3 -2.3g/cm 3 .
  • the thermal conductivity of the graphene film is 1300W/mK ⁇ 1600W/mK.
  • the tensile strength of the graphene film is 50MPa ⁇ 65MPa.
  • the present disclosure provides an electronic device, the electronic device comprising a graphene film prepared by any one of the above-mentioned graphene film preparation methods or the above-mentioned graphene film.
  • the present disclosure also provides a graphitization furnace equipment, comprising:
  • the main body of the graphitization furnace including the furnace wall, the furnace cavity surrounded by the furnace wall, and electrodes;
  • the crucible section is arranged at a position corresponding to the electrode in the furnace cavity, including a plurality of crucibles and crucible section resistance particles filled around the crucible;
  • the lower section is set in the furnace cavity below the crucible section, including the lower resistive granular layer;
  • the upper section is set in the furnace cavity above the crucible section, including the upper resistive particle layer.
  • a protective layer is also provided on the lower end of the lower section.
  • the average particle diameter of the resistive particles ranges from 0 to 30mm, excluding 0mm.
  • the graphitization furnace equipment is an Acheson graphitization furnace for producing graphene films.
  • a reduced graphene oxide film is laid in the crucible.
  • the lower resistive particle layer includes at least two layers, and the average particle size of the resistive particle layer in each layer decreases layer by layer from the upper layer to the lower layer.
  • the upper resistive particle layer includes at least four layers, and the average particle size of each resistive particle layer decreases layer by layer from the lower layer to the upper layer.
  • the lower resistive particle layer includes two layers, including a layer of resistive particle layers with average particle diameters ranging from 8 mm to 30 mm and less than or equal to 2 mm laid down sequentially from the upper layer to the lower layer.
  • the upper resistive particle layer includes four layers, including resistive particle layers with average particle diameters ranging from 8 mm to 30 mm, 5 mm to 10 mm, 2 mm to 4 mm, and less than or equal to 2 mm laid down sequentially from the lower layer to the upper layer.
  • the average particle diameter of the resistor particles in the crucible segment is 8 mm to 30 mm.
  • the graphitization furnace equipment further includes an electrode section.
  • the graphitization furnace equipment further includes an electrode section, and the electrode section is arranged between the electrode and the crucible section at a position corresponding to the crucible section.
  • the electrode segments are filled with electrode segment resistance particles.
  • the average particle diameter of the resistance particles in the electrode section is ⁇ 2mm.
  • the resistor particles include at least one of calcined petroleum coke, green petroleum coke or carbon black.
  • the present disclosure also provides the use of the above-mentioned electronic equipment or any one of the above-mentioned graphitization furnace equipment for preparing a graphene film.
  • Fig. 1 is the flow chart of the preparation method of the graphene membrane that the embodiment of the present disclosure provides;
  • Fig. 2 is a schematic structural diagram of the Acheson graphitization furnace provided by some embodiments of the present disclosure
  • Fig. 3 is a schematic structural diagram of the Acheson graphitization furnace provided by some embodiments of the present disclosure
  • Fig. 4 is a schematic structural diagram of the Acheson graphitization furnace provided by some embodiments of the present disclosure.
  • Fig. 5 is a schematic structural diagram of the Acheson graphitization furnace provided by some embodiments of the present disclosure.
  • FIG. 6e is an SEM image of the graphene film prepared in Comparative Example 1.
  • 1000-graphitization furnace equipment 1200-main body of Acheson graphitization furnace, 1220-furnace wall, 1240-furnace cavity, 1260-electrode, 1400-crucible section, 1420-crucible, 1440-crucible section resistance particles, 1460 -Reduced graphene oxide film, 1600-lower section, 1620-lower resistance granular layer, 1622-first lower resistance granular layer, 1624-second lower resistance granular layer, 1626-third lower resistance granular layer, 1640-protection layer, 1800-upper section, 1820-upper resistance particle layer, 1822-first upper resistance particle layer, 1824-second upper resistance particle layer, 1826-third upper resistance particle layer, 1828-fourth upper resistance particle layer , 1829-fifth upper resistance particle layer, 1900-electrode section, 1920-electrode section resistance particle.
  • the term "fluffy graphene film” means that the structure of the graphene film presents a loose, porous, and non-dense appearance structure, and can be used interchangeably with the term “porous fluffy graphene film”.
  • the term “compaction pressure” refers to the pressure at which a fluffy graphene film is compacted to a true density, and may be used interchangeably with the term “compaction strength”.
  • the term "average particle size” refers to the number average particle size of the particles measured by the surface of the material, for example, the average particle size can be obtained by measuring the average particle size with an instrument (such as an average particle size measuring instrument), That is, it reflects the average particle size of the material.
  • the inventors have found through research that since the graphene film is formed by stacking small graphene sheets ( ⁇ 3 ⁇ m), increasing the maximum temperature of the graphitization process and prolonging the cooling time can promote the crystallization and reorganization of small graphene sheets into large graphene sheets. Furthermore, the thermal conductivity and structural strength can be greatly improved. Therefore, a graphitization process that can stably reach above 3000°C is required, and at the same time has a slow cooling rate and is not affected by volatiles generated during the heating process.
  • One embodiment of the present disclosure provides a method for preparing a graphene film, the method comprising the following steps:
  • the fluffy graphene film is compacted and densified to obtain a graphene film.
  • One embodiment of the present disclosure provides a method for preparing a graphene film, the method comprising the following steps:
  • the reduced graphene oxide film is placed in an Acheson furnace (Acheson furnace), high-temperature heat treatment is carried out at different stages so that the reduced graphene oxide film reaches the graphitization temperature, and the fluffy graphene film is obtained by natural cooling.
  • Acheson furnace Acheson furnace
  • the high temperature heat treatment ranges from 1000°C to 3200°C.
  • the partially reduced graphene oxide film is placed in the Acheson graphitization furnace, and the resistance heating particles (resistive particles) in the Acheson graphite furnace and the partially reduced graphene oxide film together constitute the furnace resistance, and the Apply current to make the current flow through the resistance heating particles (resistor particles) in the furnace and the partially reduced graphene oxide film to generate huge heat energy, so that the partially reduced graphene oxide film can obtain the heat required for graphitization, and realize the graphitization of the product.
  • the core graphitization temperature in the crucible remains stable, which can realize Natural slow cooling during the cooling of the resistance particles, during the subsequent cooling of the resistance particles, by slowly and alternately removing the resistance heating particles (resistor particles), further making the graphene film in the long cooling process (20 days to 30 days)
  • the recrystallization of the structure is realized to generate large-area crystal domains, which improves the electrical, thermal and mechanical properties of the product.
  • the graphitization method using Acheson graphitization furnace is simpler, easier to implement, reliable in mass production and has an extremely low failure rate.
  • due to the long-term use reliability, low failure rate, high degree of graphitization, and simple process of the Acheson graphitization furnace it not only reduces the overall manufacturing cost of the graphene film, but also greatly improves the material performance.
  • Fig. 1 is the flow chart of the preparation method of the graphene film that the embodiment of the present disclosure provides, in conjunction with Fig. 1, introduces this embodiment as follows:
  • Step S10 baking the graphene oxide film prepared from the slurry containing graphene oxide or graphite oxide to obtain a reduced graphene oxide film.
  • graphene oxide or graphite oxide can be added to a solvent to make a slurry, and the slurry containing graphene oxide or graphite oxide can be homogenized by ultrasonication, mechanical shearing, mechanical stirring, and high-pressure homogenization. Any one of the methods can be mixed.
  • the preparation process of the graphene oxide film comprises any one of suction filtration process, dip coating process, spin coating process, spraying process, evaporation process and coating process.
  • the slurry can be coated and dried to form a graphene oxide film.
  • the concentration of the slurry is 1 mg/mL-80 mg/mL, such as 5 mg/mL-80 mg/mL, 10 mg/mL-70 mg/mL or 20 mg/mL-60 mg/mL, in some embodiments
  • the concentration of slurry can be 1mg/mL, 5mg/mL, 10mg/mL, 15mg/mL, 20mg/mL, 30mg/mL, 40mg/mL, 50mg/mL, 60mg/mL, 70mg/mL or 80mg/mL mL etc., of course, can also be other values within the above range, which are not limited here.
  • the concentration of the slurry refers to the amount of solute contained in a unit solvent, and the solute may be graphene oxide and/or graphite oxide, which is not limited here.
  • the dispersion treatment includes at least one of ultrasonic dispersion, mechanical shear peeling dispersion, mechanical stirring dispersion, and high-pressure homogeneous dispersion.
  • the baking temperature is 150°C-550°C, such as 200°C-550°C, 250°C-500°C or 300°C-400°C
  • the heating rate is 0.5-10°C/h, For example, 1-10°C/h, 1-5°C/h or 1.5-4.5°C/h; specifically, it can be 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C or 550°C °C, etc.
  • the heating rate can be 0.5°C/h, 1°C/h, 1.5°C/h, 2°C/h, 2.5°C/h, 3°C/h, 3.5°C/h, 4°C/h, 4.5°C
  • /h and 5° C./h may also be other values within the above range, which are not limited here.
  • the graphene oxide film contains a large amount of water and oxygen-containing chemical functional groups (such as hydroxyl/carboxyl/epoxy groups, etc.), it is necessary to remove water and oxygen-containing chemical functional groups before high-temperature graphitization.
  • water and oxygen-containing chemical functional groups such as hydroxyl/carboxyl/epoxy groups, etc.
  • rapid volatilization leads to an increase in the inner cavity pressure of the graphene film, which is not only unfavorable for later crystallization, but may even cause bursting, which is convenient for subsequent graphitization treatment.
  • the volatile component in the baked graphene oxide film is lower than (less than or equal to) 10wt%, for example, 1-10wt%, 2-9wt% or 3-6wt%, Specifically, it can be 9wt%, 8wt%, 7wt%, 6wt%, 5wt%, 4wt%, 3wt%, 2wt% or 1wt%, etc. Of course, it can also be other values within the above range, which is not limited here.
  • this step can be omitted, and a reduced graphene oxide film that meets the above conditions can be directly selected, that is, a reduced graphene oxide film with a volatile component of less than 10 wt % can be selected.
  • Step S20 putting the reduced graphene oxide film into an Acheson graphitization furnace, performing high-temperature heat treatment at different stages so that the reduced graphene oxide film reaches the graphitization temperature, and cooling down naturally to obtain a fluffy graphene film.
  • the resistive heating particles include but are not limited to at least one of calcined petroleum coke, green petroleum coke or carbon black.
  • the reduced graphene oxide film and graphite paper can be laminated and placed into the crucible in the Acheson graphitization furnace, and the crucible in the Acheson graphitization furnace is connected to the crucible
  • the surface is paved and filled with the resistance heating particles (resistive particles).
  • the heating method of the Acheson graphitization furnace is to apply current to make it flow through the resistance heating particles (resistance particles), so that the resistance heating particles (resistance particles) heat up and reach the graphitization temperature, so as to heat the reduction Graphene oxide film.
  • the resistance heating particles (resistance particles) include calcined coke with different particle diameters, and the average particle diameter of the calcined coke ranges from 0 to 30 mm, excluding 0 mm.
  • the crucible is a customized rectangular crucible, and the size of the crucible can be customized according to the size of the graphene film, so as to maximize the utilization of the space in the crucible.
  • An embodiment of the present disclosure provides a graphitization furnace equipment, including:
  • the main body of the graphitization furnace including the furnace wall, the furnace cavity surrounded by the furnace wall, and electrodes;
  • the crucible section is arranged at a position corresponding to the electrode in the furnace cavity, including a plurality of crucibles and crucible section resistance particles filled around the crucible;
  • the lower section is set in the furnace cavity below the crucible section, including the lower resistive granular layer;
  • the upper section is set in the furnace cavity above the crucible section, including the upper resistive particle layer.
  • the lower end of the lower section is further provided with a protective layer.
  • the average particle size of the resistive particles ranges from 0 to 30 mm, excluding 0 mm.
  • a reduced graphene oxide film is laid in the crucible.
  • the graphitization furnace body is an Acheson graphitization furnace body.
  • the resistance heating particles generate heat with their own resistance, and are combined with the reduced graphene oxide film Together constitute the furnace resistance, so that the current flows through the resistance heating particles (resistor particles) and the reduced graphene oxide film in the furnace to generate co-heating.
  • the resistance of the resistance heating particles (resistor particles) is extremely important for temperature control. How is the resistance arranged?
  • resistance heating particles resistance heating particles of different resistance values and resistance heating particles (resistance particles) of different particle sizes, not by adding a certain resistance heating particles (resistance particles) or directly This can be accomplished by techniques known in the art.
  • the arrangement of the resistance heating particles (resistance particles) of the present disclosure can not only realize the required high temperature, but also effectively maintain the unity, uniformity and stability of the internal furnace resistance.
  • the present disclosure also provides a graphitization furnace equipment (arrangement) 1000, comprising:
  • Acheson graphitization furnace main body 1200 including furnace wall 1220, furnace cavity 1240 surrounded by furnace wall 1220 and electrodes 1260;
  • a crucible section (section) 1400 is arranged at a position corresponding to the electrode 1260 in the furnace chamber 1240, and includes a plurality of crucibles 1420 and crucible section resistance particles filled around the crucible 1420;
  • the lower section (up section) 1600 is set in the furnace cavity 1240 below the crucible section 1400, including the lower resistance particle layer 1620;
  • the upper section (down section) 1800 is set in the furnace chamber 1240 above the crucible section 1400 and includes an upper resistive particle layer 1820 .
  • the lower resistive particle layer is also referred to as the resistive particle layer below the crucible.
  • the upper resistive particle layer is also referred to as the resistive particle layer above the crucible.
  • a reduced graphene oxide film 1460 is laid in the crucible.
  • the conventional Acheson graphitization furnace is basically used to produce graphite materials, etc.
  • the resistance material expands due to high-temperature graphitization, Since the graphite material to be processed is a solid block structure in structure, and in the heating section loaded with graphite material, the material can fill the heating section without leaving gaps, and the heating section will not cause accidents due to the absence of gaps.
  • the expansion of the heating section caused by the expansion of the resistance material causes cracking, bursting, and even the bursting of the entire furnace body, and the production can proceed smoothly.
  • the prior art has never disclosed the technology of utilizing the Acheson graphitization furnace to prepare graphene membranes. This is because the prior art cannot overcome the following technical difficulties and defects: since the material produced is a membrane material, the membrane material itself It is not a solid structure, and in the heating section loaded with membrane material, since the membrane material cannot fill the heating section, there will inevitably be many gaps between the membrane and the membrane. During the production process, conventional resistance particles (resistance heating particles) will squeeze the crucible loaded with membrane material due to high-temperature graphitization expansion, which will eventually lead to cracking, bursting of the crucible in the heating section, and even bursting of the furnace body.
  • resistance heating particles resistance heating particles
  • the graphitization furnace equipment 1000 provided by the present disclosure can break through this technical difficulty and defect, and realize the production of graphene film under the conditions of ultra-high temperature and long-term production.
  • the graphitization furnace equipment 1000 for the production of graphene film in the present disclosure is improved based on the conventional Acheson graphitization furnace, and the heating and heat preservation structure is specially set, which is realized in some embodiments as follows.
  • the lower section 1600 further includes a protective layer 1640 disposed under the lower resistive particle layer.
  • the lower resistive particle layer and the protective layer 1640 are laid sequentially from the upper layer to the lower layer (ie along the direction away from the crucible 1420 ) in the chamber 1240 of the Acheson graphitization furnace body 1200 located below the crucible 1420 . It is believed, without being bound by theory, that the resistive particles vary in particle size to control the resistance value of the resistive particles.
  • the thickness of the protective layer 1640 may be 500mm-900mm, for example, 500mm-600mm, 600mm-900mm, 600mm-800mm, such as 500mm, 600mm, 700mm, 800mm, 900mm.
  • the resistance of the protection layer 1640 is ⁇ 1000 ⁇ .
  • protective layer 1640 is a carbon black protective layer.
  • the resistance of the protective layer of the present disclosure is within the above range, so that during the heating process, the current will not first flow through the protective layer, and at the same time, the resistance and thickness of the protective layer of the present disclosure are within the above range so that the protective layer plays a good role in heat preservation, and at the same time It has excellent temperature resistance, and protects the bottom of the furnace from being burned through at 3000°C and above, thereby further improving the overall heat insulation effect of the furnace.
  • the lower resistance particle layer 1620 may include at least two layers. In some embodiments, the average particle size of the lower resistance particle layer 1620 decreases layer by layer from the upper layer to the lower layer (ie along the direction away from the crucible 1420 ).
  • the current first flows through the lower resistive granular layer whose average particle diameter of the resistive granular layer is relatively small (that is, the resistance is relatively small), and the average particle diameter of the resistive granular layer is Relatively small, the distribution is denser, and the input of current is more continuous and stable, so the resistance particle layer can continue to generate heat stably, and play a good role in heat preservation, prolong the heat preservation time of graphitization, reduce the direct heat exchange with air, and play a role It has a good effect of isolating the air, and then improves the graphitization rate of the product; after the current flows through the upper layer of the resistance particle layer with relatively large particles (that is, relatively large resistance), the layer of resistance particles continues to heat, but the particle layer The particle size is relatively large, that is, the resistance is relatively large, and the resistance particles will not produce the above-mentioned excessive expansion due to overheating, thereby ensuring the efficient progress of graph
  • the resistance value (resistivity) of the resistor particles gradually decreases, so that the current continues to flow, and the current continues to flow through the upper section (described below), from the resistor
  • the average particle size of the particle layer flows through in order from small to large.
  • the heating process of the resistance particles is cyclical and progressive.
  • the particle size distribution of the resistance particle layer in the present disclosure is to effectively exert the heating of the particle layer away from the crucible end and the main heat preservation, prolong the heat preservation time of graphitization, and isolate the air; and the heating effect of the particle layer near the crucible end, while avoiding The overheating of the particles effectively suppresses the expansion of the resistor particles, thus avoiding the crucible from breaking.
  • the lower resistance particle layer 1620 includes: a first lower resistance particle layer 1622 and a second lower resistance particle layer 1624, wherein the second lower resistance particle layer 1624 is disposed below the bottom of the crucible 1420, and the second The lower resistive particle layer 1622 is disposed below the second lower resistive particle layer 1624 .
  • the first lower resistance particle layer 1622 has particles with an average particle size ranging from greater than 0 to less than or equal to 2 mm, such as 0.1 mm ⁇ 1.8 mm, 0.5 mm ⁇ 1.5 mm, or 1 mm ⁇ 1.3 mm.
  • the resistance value of the first resistive granular material layer is 450 ⁇ ⁇ 600 ⁇ , such as 480 ⁇ ⁇ 580 ⁇ , 500 ⁇ ⁇ 550 ⁇ , or 510 ⁇ ⁇ 530 ⁇ .
  • the second lower resistance particle layer 1624 has particles with an average particle size ranging from 8 mm to 30 mm, such as 10 mm to 25 mm, 12 mm to 20 mm, or 15 mm to 18 mm.
  • the resistance value of the second lower resistive particle layer 1624 is 450 ⁇ ⁇ 600 ⁇ , such as 480 ⁇ ⁇ 580 ⁇ , 500 ⁇ ⁇ 550 ⁇ , or 510 ⁇ ⁇ 530 ⁇ .
  • the thickness of the first lower resistance particle layer 1622 is 5cm-25cm, or 7cm-20cm, or 8cm-15cm, or 9cm-12cm.
  • the thickness of the second lower resistive particle layer 1624 is 5cm-25cm, or 7cm-20cm, or 8cm-15cm, or 9cm-12cm.
  • the total thickness of the layer of resistive particles below the crucible 1420 is 10 cm to 50 cm, or 15 cm to 40 cm, or 16 cm to 30 cm, or 10 cm to 25 cm.
  • the first lower resistive granular layer 1622 and the second lower resistive granular layer 1624 include or consist of calcined coke.
  • the distribution and combination of the lower resistance particle layer in the above-mentioned different particle size ranges adopted by the present disclosure not only realizes the stable conditions of ultra-high temperature and long-term heating, but also does not cause a heating section due to the gap between the loaded film materials to be processed. (crucible section) or rupture of the entire furnace body.
  • the combination of the lower resistance particle layer provided by the present disclosure suppresses the expansion of the heating particles during the heating process, so the gaps existing in the above-mentioned crucible do not cause the heating particles surrounded by the crucible to squeeze the crucible due to heat expansion, causing the crucible to collapse and rupture as a whole . .
  • the second lower resistance particle layer is within the above particle size range, which plays a role of heating and effectively inhibits the expansion of resistance particles.
  • the specific arrangement of resistor particles with different particle sizes achieves the characteristics of stable high temperature, heat preservation, and air isolation, and prevents the above-mentioned problems caused by particle expansion.
  • the range of the average particle size of the particle layer (such as the second lower resistance particle layer) near the crucible avoids the particle size being too small, resulting in high-temperature graphitization expansion, and the particles are easy to squeeze the crucible to cause rupture, and also avoids
  • the average particle size is too large, and the current flowing through the particles caused by the uneven heating, and easy to enter the air, can not achieve the heat preservation effect, and the ultra-high graphitization temperature is above 3000 °C.
  • the lower resistive particle layer 1620 further includes a third lower resistive particle layer disposed below the first lower resistive particle layer 1622 .
  • the average particle diameter of the third lower resistive granular layer is greater than 0 and less than or equal to 0.5mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm.
  • the thickness of the third lower resistance granular material layer is 5cm-25cm, or 7cm-20cm, or 8cm-15cm, or 9cm-12cm.
  • the addition of the third lower resistance particle layer and the addition of the additional lower resistance particle layer 1620 can be selectively increased according to the heat preservation time and cooling requirements, which can further improve the functions of heat preservation and air isolation.
  • the lower resistive particle layer 1620 further includes a fourth lower resistive particle layer disposed below the third lower resistive particle layer.
  • the average particle diameter of the fourth lower resistive granular layer is greater than 0 and less than or equal to 0.5mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm.
  • the lower resistive particle layer 1620 further includes a fifth lower resistive particle layer disposed below the fourth lower resistive particle layer.
  • the average particle size range of the fifth lower resistive particle layer is greater than 0 and less than or equal to 0.5mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm.
  • the resistance value of the lower resistance particle layer 1620 is 450 ⁇ ⁇ 600 ⁇ .
  • the lower resistive particle layer 1620 includes or consists of two layers, and the layers with average particle diameter ranging from 8 mm to 30 mm and less than Equal to 2mm resistive particle layer.
  • the lower resistive particle layer includes or consists of three layers, and layers are sequentially laid from the upper layer to the lower layer (that is, along the direction away from the crucible) with particles having an average particle size ranging from 8 mm to 30 mm, less than or equal to 2 mm. And a layer of resistance particles less than or equal to 0.5mm.
  • a layer of carbon black can be laid on the bottom of the main body 1200 of the Acheson graphitization furnace
  • the protective layer 1640, the thickness of the carbon black protective layer 1640 is 700 mm, the resistance value of the carbon black protective layer 1640 is ⁇ 1000 ⁇ ; the carbon black protective layer is covered with a first lower resistance particle layer 1622, the first lower resistance particle layer 1622 It includes calcined coke with particle size (average particle diameter) less than or equal to 2 mm, and the resistance value of the first resistance heating particle layer (first lower resistance particle layer 1622 ) is 450 ⁇ ⁇ 600 ⁇ .
  • the second lower resistance granular layer 1624 includes calcined coke with a particle size (average particle diameter) of 8 mm to 30 mm, and the second lower resistance granular layer 1624 The resistance value of the resistance particle layer 1624 is 450 ⁇ ⁇ 600 ⁇ .
  • the layer of resistive particles and the carbon black layer at the bottom of the crucible can achieve good heating and temperature control effects, effectively maintaining uniform heating and stable heat release in the furnace.
  • an upper resistive particle layer 1820 is laid in the chamber 1240 of the Acheson graphitization furnace body 1200 above the crucible 1420 .
  • the upper resistive particle layer 1820 may include at least four layers, such as four or more layers, five or more layers, six or more layers.
  • the average particle size of the upper resistive particle layer 1820 decreases layer by layer from the lower layer to the upper layer (ie along the direction away from the crucible 1420 ).
  • the particle size distribution of the resistance particle layer in the present disclosure is to effectively exert the heating effect of the particle layer near the crucible, effectively inhibit the crucible from breaking due to particle expansion, and effectively exert the heating, heat preservation and isolation of the particle layer far away from the crucible. air action.
  • the thickness of each layer of resistive particles above the crucible 1420 is independently 5 cm to 25 cm, or 7 cm to 20 cm, or 8 cm to 15 cm, or 9 cm to 12 cm. Referring to FIG.
  • the upper resistive granular layer 1820 includes: a first upper resistive granular layer 1822 disposed above the top of the crucible 1420 ; a second upper resistive granular layer 1824 disposed on the first upper resistive granular layer 1822 above; the third upper resistive granular layer 1826 is disposed above the second upper resistive granular layer 1824 ; the fourth upper resistive granular layer 1828 is disposed above the third upper resistive granular layer 1826 .
  • the first upper resistive particle layer 1822 has particles with an average particle size greater than the second upper resistive particle layer has particles with an average particle size.
  • the second upper resistive particle layer 1824 has particles with an average particle size greater than the third upper resistive particle layer 1826 has particles with an average particle size.
  • the third upper resistive particle layer 1826 has particles with an average particle size greater than the fourth upper resistive particle layer 1828 has particles with an average particle size.
  • the average particle size of the resistive particles is: first upper resistive particle layer 1822 > second upper resistive particle layer 1824 > third upper resistive particle layer 1826 > fourth upper resistive particle layer 1828 .
  • the first upper resistive particle layer 1822 has particles with an average particle size ranging from 8 mm to 30 mm, such as 10 mm to 25 mm, 12 mm to 20 mm, or 15 mm to 18 mm.
  • the second upper resistive particle layer 1824 has particles with an average particle size ranging from 5 mm to 10 mm, such as 6 mm to 9 mm, or 7 mm to 8 mm.
  • the third upper resistive particle layer 1826 has particles with an average particle size ranging from 2 mm to 4 mm, such as 2.5 mm to 3.5 mm, or 2.8 mm to 3 mm.
  • the fourth upper resistive particle layer 1828 has particles with an average particle size ranging from greater than 0 to less than or equal to 2 mm, such as 0.1 mm ⁇ 1.8 mm, 0.5 mm ⁇ 1.5 mm, or 1 mm ⁇ 1.3 mm.
  • the thicknesses of the first upper resistive granular layer 1822, the second upper resistive granular layer 1824, the third upper resistive granular layer 1826, and the fourth upper resistive granular layer 1828 are independently 5 cm to 25 cm, or 7 cm to 25 cm. 20cm, or 8cm to 15cm, or 9cm to 12cm. In some embodiments, the total thickness of the layer of resistive particles above the crucible 1420 is 20cm-100cm, or 30cm-80cm, or 35cm-60cm, or 30cm-50cm.
  • the distribution and combination of the upper resistance particle layer in the above-mentioned different particle size ranges adopted by the present disclosure not only achieves an ultra-high graphitization temperature and a long-term stable core graphitization temperature, but also does not suffer from the gap between the crucible carrying film materials. Cracks are caused by the expansion and extrusion of resistance particles due to the existence of hollow gaps.
  • the combination of the upper resistive particle layer provided by the present disclosure can effectively suppress the expansion during the graphitization process, so that the above-mentioned cracking due to the expansion and extrusion of the resistive particle due to improper filling is not caused. .
  • the special arrangement of the upper resistance particle layer of the present disclosure not only exerts the heating effect on adjacent crucible positions (such as the first upper resistance particle layer, the second upper resistance particle layer) and effectively inhibits the expansion of the resistance particles, but also more effectively exerts the heat away from the crucible.
  • the heating, heat preservation, and air isolation of the resistance granular layer (such as the third upper resistance granular layer and the fourth upper resistance granular layer) of the crucible in summary, the expansion of the resistance granular layer during the whole graphitization process is effectively suppressed.
  • the range of the average particle size of the particle layer (such as the first upper resistance particle layer) near the crucible avoids the particle size being too small, resulting in high-temperature graphitization expansion, and the particles are easy to squeeze the crucible to cause rupture, and also avoids
  • the average particle size is too large, and the current flowing through the particles causes uneven heating, and it is easy to enter the air, which cannot achieve the heat preservation effect, and the ultra-high graphitization temperature is above 3000°C
  • the upper resistance particle layer of the present disclosure also has the characteristics of stable high temperature, heat preservation, and air isolation, and prevents the above-mentioned problems caused by particle expansion.
  • the properties of softening, heat preservation and air isolation are particularly important.
  • the upper resistive particle layer further includes a fifth upper resistive particle layer disposed above the fourth upper resistive particle layer.
  • the average particle diameter of the fifth upper resistive granular layer is smaller than that of the fourth upper resistive granular layer.
  • the average particle diameter of the fifth upper resistive granular layer ranges from greater than 0 to less than or equal to 0.5mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm.
  • the thickness of the fifth upper resistive particle layer may be 5 cm to 25 cm, or 7 cm to 20 cm, or 8 cm to 15 cm, or 9 cm to 12 cm.
  • the increase of the above-mentioned upper resistive particle layer can be selectively increased according to the heat preservation time requirement and cooling requirement, which can further improve the effect of heat preservation and air isolation, and can realize the graphitization temperature range of 3000°C to 3200°C.
  • the upper resistive particle layer 1820 includes or consists of four layers, and layers with average particle diameters ranging from 8 mm to 30 mm and 5 mm are sequentially laid from the lower layer to the upper layer (that is, along the direction away from the crucible 1420). ⁇ 10mm, 2mm ⁇ 4mm and less than or equal to 2mm resistance particle layer.
  • the achievable cooling rate is 5° C./h to 15° C./h, and the cooling time is 20 days to 30 days.
  • the upper resistive particle layer 1820 includes or consists of five layers, and layers with average particle diameters ranging from 8 mm to 30 mm and 5 mm are sequentially laid from the lower layer to the upper layer (that is, along the direction away from the crucible 1420). ⁇ 10mm, 2mm ⁇ 4mm or less than 2mm and less than or equal to 0.5mm resistance particle layer.
  • a calcined coke of 8 mm to 30 mm is laid between the outer wall of the crucible and the crucible, and a layer of 8 mm to 30 mm of calcined coke is first covered on the upper layer of the crucible.
  • calcined cokes with different particle sizes generate different Joule heat when electrified in the graphitization furnace.
  • resistance heating particles resistive particles
  • the furnace resistance is formed, so that the current flows through the resistance heating particles (resistance particles) in the furnace and the reduced graphene oxide film to generate co-heating, so that the reduced graphene oxide film obtains the heat required for graphitization.
  • the uppermost layer of resistance heating particles due to the small particle size and dense landfill, the heat preservation effect is more conducive to protecting the temperature in the furnace, prolonging the heat preservation time of graphitization, and thus improving the graphitization rate of the product.
  • the choice to use calcined cooked coke is mainly because the resistance value is more stable, and the carbon content of cooked coke exceeds 99%, so there is no volatile matter.
  • the three-layer arrangement of the carbon black layer and the resistance particle layer at the bottom of the crucible plays a good role in shielding air and heat insulation; in the above-mentioned embodiment
  • the four-layer arrangement of resistive particles on the top of the crucible plays a good role in isolating air and keeping warm, and can achieve a graphitization temperature range of 3000 ° C to 3200 ° C.
  • the layer of resistive particles on top of the crucible allows for good heating and subsequent natural slow cooling.
  • the small molecule volatiles produced by the graphene oxide film such as carbon dioxide, carbon monoxide, nitrogen-containing compounds, etc., will be absorbed by the powdery porous resistance heating particles (resistive particles), and will not It will not cause any waste discharge, and the resistance heating particles (resistance particles) are cheap and can be reused after being calcined.
  • the crucible segment resistive particles 1440 filled around the crucible 1420 have an average particle size of 8 mm to 30 mm.
  • the graphitization furnace apparatus 1000 further includes an electrode section 1900 .
  • the electrode section 1900 is disposed between the electrode 1260 and the crucible section 1400 at a location corresponding to the crucible section 1400 .
  • electrode segment 1900 is filled with electrode segment resistive particles 1920 .
  • the average particle size of the electrode segment resistive particles 1920 is ⁇ 2 mm.
  • the graphitization temperature range is 3000° C. to 3200° C.; the heat treatment period in the high temperature heat treatment is 10 days to 30 days. It can be understood that due to the high graphitization temperature and long holding time, the product can realize the repair of its own structural defects in a longer graphitization cycle, and at the same time, the internal structure of the graphene film can be recrystallized to form large-area crystal domains, so that The electrical, thermal and mechanical properties of the product are optimized.
  • the graphitization temperature can be, for example, 3000°C-3100°C, 3100°C-3200°C, 3020°C-3180°C, such as 3000°C, 3050°C, 3100°C, 3150°C, 3200°C, etc.
  • the heat treatment cycle It can be, for example, 10 days to 25 days, 12 days to 30 days, 15 days to 30 days or 20 days to 30 days, such as 10 days, 15 days, 18 days, 20 days, 25 days, 28 days or 30 days, etc. , of course, can also be other values within the above range, which is not limited here.
  • the temperature is raised to the graphitization temperature in stages.
  • the Acheson graphitization furnace includes a furnace body, which is a regular tetrahedron structure surrounded by a furnace base, a furnace head wall, a furnace tail wall and a furnace wall plate.
  • the furnace head wall and Conductive electrodes are arranged in the furnace tail wall, and the quartz sand and carbon black insulation layers are laid sequentially on the furnace base.
  • the furnace core is placed on the insulation layer, and the graphite crucible is placed on the furnace core and set along the direction of the furnace.
  • the upper layer is alternately laid with layers of embedded resistance heating particles (resistance particles), the top and sides of the furnace core are provided with molding plates, and the embedded resistance heating particles (resistance particles) are laid in the molding plates.
  • step S20 includes
  • the temperature of the Acheson graphitization furnace is raised to 1000°C to 1400°C, and the temperature is kept for 5h to 10h;
  • the temperature in the Acheson graphitization furnace is continuously raised to 2000°C-2100°C, and kept for 5h-10h;
  • step S20 the temperature rise in the first stage mainly completes the cracking and volatilization of some compounds in the product. If this stage is not retained, it is easy for some compounds to be directly graphitized before being volatilized and trapped in the product structure, resulting in defects, such as pores.
  • the second stage of temperature rise and maintenance is mainly at the beginning of graphitization.
  • the graphitization temperature starts at 2000°C. This process is the process of carbon nucleation. If it is not retained, it will easily produce polycrystalline state and crystallization will produce impurities.
  • the third stage of heating is the real graphitization crystallization growth stage.
  • the temperature in this stage is the highest (the temperature reaches 3000 °C ⁇ 3200 °C).
  • the crystallization starts epitaxial growth through a uniform crystal nucleus, forming a large-area single crystal, so that the physical properties of the product are improved in all aspects. improve.
  • the graphitization start temperature of the reduced graphene oxide film is about 2100°C. At 2100°C, the C-C bond breaks, but a higher temperature is required for the breakage of the C-C bond of the benzene ring. As the temperature increases, the C-C bond breaks more Thoroughly, after the C-C bond is broken, the recombination crystallizes to obtain a perfect crystal.
  • the reduced graphene oxide film of the present disclosure can be treated at a high temperature during the above-mentioned graphitization crystallization growth stage, so that the C-C bond can be broken more thoroughly, and a large-area single-crystal graphene film can be obtained. , thereby further improving the physical properties of the graphene film such as thermal conductivity and electrical conductivity.
  • the third stage when the temperature in the Acheson graphitization furnace reaches 2900°C, heat preservation is carried out first, and then the graphitization temperature is raised to 3000°C to 3200°C, so that the temperature in the furnace can be uniform and the graphene film in the crucible can be heated Uniformity, and then improve the orientation of the crystal, so that the product performance is improved.
  • the cooling rate of natural cooling is 5 °C/h-15 °C/h, and the cooling time is 9 days to 30 days.
  • the cooling rate can be, for example, 5°C/h to 8°C/h, 6°C/h to 15°C/h, 5°C/h to 10°C/h, or 8°C/h to 15°C/h , such as 5°C/h, 7°C/h, 8°C/h, 10°C/h, 12°C/h, 13°C/h, 14°C/h or 15°C/h, etc., are not limited here.
  • the cooling time is for example 9 days to 20 days, 10 days to 30 days, 15 days to 30 days or 12 days to 28 days, such as 9 days, 10 days, 11 days, 12 days, 15 days, 17 days, 19 days, 20 days, 25 days or 30 days, etc., are not limited here. It should be noted that in the cooling process, the cooling rate in the early stage of cooling is faster, and the cooling rate in the later stage of cooling is slower, that is, the closer the temperature in the furnace is to room temperature, the slower the cooling.
  • graphene achieves defect repair and structural recrystallization in the slow cooling process to obtain graphene membranes, which can promote the crystallization and reorganization of small graphene sheets into large graphene sheets, and improve the performance of graphene.
  • the crystallization process usually occurs during the cooling process. The slower the cooling rate, the better the crystallization degree and the better the product performance. Rapid cooling will lead to poor crystal orientation, formation of microcrystals, and product performance degradation.
  • Step S30 performing compaction and densification treatment on the fluffy graphene film to obtain a graphene film.
  • the compaction pressure of the fluffy graphene film is 2MPa-100MPa, such as 5MPa-100MPa, 10MPa-100MPa, 50MPa-100MPa or 2MPa-80MPa, such as 2MPa, 5MPa, 10MPa, 20MPa, 30MPa, 35MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, or 100MPa, etc., of course, can also be other values within the above range, which are not limited here.
  • the graphene membrane structure can be made stronger and denser.
  • An embodiment of the present disclosure provides a graphene film, which is prepared by the preparation method described in the first aspect above.
  • the thickness of the graphene film is 10 ⁇ m to 300 ⁇ m, specifically 10 ⁇ m, 50 ⁇ m, 100 ⁇ m, 150 ⁇ m, 200 ⁇ m, 250 ⁇ m, 280 ⁇ m or 300 ⁇ m, etc., which is not limited here.
  • the thickness of the graphene film can be measured by a thickness tester.
  • the density of the graphene film is 1.8g/cm 3 -2.3g/cm 3 , specifically 1.8g/cm 3 , 1.9g/cm 3 , 2.0g/cm 3 , 2.1 g/cm 3 , 2.2 g/cm 3 or 2.3 g/cm 3 , etc., of course, can also be other values within the above range, which are not limited here. It can be understood that the increase in the density of the graphene film is conducive to the application of light and thin products.
  • the thermal conductivity of the graphene film is 1300W/mK ⁇ 1600W/mK, specifically 1300W/mK, 1350W/mK, 1400W/mK, 1450W/mK, 1500W/mK, 1550W /mK or 1600W/mK, etc., of course, can also be other values within the above range, which are not limited here.
  • the thermal conductivity of the graphene film can be measured by ASTM-E1461 standard.
  • the tensile strength of the graphene film is 50MPa to 65MPa, specifically 50MPa, 52MPa, 55MPa, 58MPa, 60MPa, 62MPa or 65MPa, etc. Of course, it can also be other within the above range. value, which is not limited here.
  • the tensile strength of the graphene film is within the above range, it is beneficial to improve the mechanical properties of the graphene film, and can improve the tear resistance of the graphene film.
  • the tensile strength of graphene film can be measured by GB/T 1040.1-2018 standard.
  • An embodiment of the present disclosure provides an electronic device, the electronic device comprising a graphene film prepared by the method for preparing a graphene film according to the first aspect above or the graphene film according to the second aspect above.
  • the graphene film and its preparation method provided by the present disclosure can reduce the production cost, shorten the preparation process, and improve the performance of the graphene film.
  • the preparation method of the graphene film provided by the present disclosure includes: putting the reduced graphene oxide film into a crucible of an Acheson graphitization furnace, and laying and filling resistance heating materials with different particle sizes on the outer wall of the crucible.
  • the internal resistance particles and the reduced graphene oxide film of the graphitization furnace based on the Acheson graphite furnace provided by the present disclosure jointly constitute the furnace resistance, and by applying a large current, the current flows through the furnace resistance particles and the reduced graphene oxide film to jointly generate Great heat.
  • the reduced graphene oxide film generates heat due to its own resistance, and at the same time, the different particle resistance particles buried on the outer wall of the crucible also generate heat due to their own resistance, and form a co-heat with the reduced graphene oxide film inside the crucible, forming a co-heating body inside and outside the crucible. Thereby achieving ultra-high graphitization temperature.
  • the core graphitization temperature in the crucible remains stable, so that the structural defects of graphene film products can be maintained at ultra-high temperature graphitization temperature and during the ultra-long graphitization heat preservation process. was perfectly repaired.
  • the resistance particles in this disclosure not only can the required high temperature be continuously and stably provided, but also have the functions of heat generation, heat preservation and air isolation, and effectively maintain the uniformity, uniformity and uniformity of the internal furnace resistance. Stability, which further improves the thermal conductivity and electrical conductivity of the graphene film; if the selected resistance particles are too small, they will expand after high-temperature graphitization, and the particles will easily squeeze the crucible to cause rupture; if the selected resistance particles are too large, the current flowing through the particles will not generate heat. It is uniform and easy to enter the air. At the same time, the heat preservation effect cannot be achieved, and the Joule heat is difficult to reach above 3000 ° C.
  • the present disclosure obtains stable high temperature, heat preservation, and air isolation through the specific arrangement of resistance particles with different particle sizes. characteristic.
  • the resistive particles are slowly and alternately removed, and the graphene film is further recrystallized to form large-area crystal domains during the long cooling process, so that the electrical, thermal, and mechanical properties of the product reach unprecedented heights.
  • the graphitization method using the graphitization furnace provided by the present disclosure is simpler, easier to implement, reliable in mass production, and has an extremely low failure rate.
  • the resistance particles in the graphitization furnace and the partially reduced graphene oxide film in the crucible produce a huge co-heating effect after the current flows through them due to their high resistance, so that the product reaches an ultra-high graphitization temperature.
  • the heating principle is different from that of Other graphitization heating methods. Due to the long-term use reliability of the graphitization furnace provided by the present disclosure, low failure rate, high degree of graphitization, and simple process, it not only reduces the overall manufacturing cost of the graphene film, but also greatly improves the material performance. The core competitiveness of the company has been strengthened.
  • Average particle size through a particle size tester, the model is Malvern laser particle size analyzer 3000, to detect and analyze the average particle size of the granular material;
  • thermal conductivity (W/mK) density ⁇ 0.85 ⁇ thermal diffusivity
  • 0.85 is the specific heat capacity of graphene film, unit J/g K; Density then is the density of the graphene film measured in above (2); Standard test method for thermal diffusivity), measured by laser thermal conductivity meter LA467;
  • Preparation method a preparation method of graphene film, comprising the following steps:
  • the baked reduced graphene oxide film and graphite paper into the graphite crucible, then stack the graphite crucible into the Acheson graphitization furnace, and adopt the staged power transmission and heating method for graphitization deal with.
  • the maximum power output is used to promote the current density in the furnace to quickly reach the heating condition, so that the furnace body can be freely heated to 1200 ° C and kept for 10 hours; in the second stage, the output power is adjusted Under the condition of full load and high current, the product is pulled up to 2100°C and kept warm for 10 hours.
  • the third stage is to adjust the output power to quickly pull the product up to 2900°C under high current and hold it for 3 hours.
  • the temperature was steadily increased to 3200°C under the stable output power of low current, and after maintaining the low current output power for 5 hours, the product achieved structural defect repair and recrystallization during the natural cooling process that lasted for 21 days to obtain a fluffy graphene film.
  • graphitization furnace equipment 1000 including:
  • Acheson graphitization furnace main body 1200 including furnace wall 1220, furnace cavity 1240 surrounded by furnace wall 1220 and electrodes 1260;
  • the crucible section 1400 is arranged at a position corresponding to the electrode 1260 in the furnace cavity 1240, including a plurality of crucibles 1420 and crucible section resistance particles 1440 filled around the crucible 1420, and a reduced graphene oxide film 1460 is laid in the crucible 1420;
  • the section 1600 is set in the furnace cavity 1240 below the crucible section 1400, including the lower resistance particle layer 1620; and the upper section 1800, is set in the furnace cavity 1240 above the crucible section 1400, including the upper resistance particle layer 1820;
  • the lower resistance heating particle layer includes a first lower resistance particle layer 1622 and a second lower resistance particle layer 1624 laid on the upper layer of the first lower resistance particle layer 1622;
  • the first lower resistance particle layer 1622 includes particle average particles Calcined coke with a diameter of 1 mm, and the resistance value of the first lower resistance granular material layer 1622 is 450 ⁇ 600 ⁇ ;
  • the second lower resistance granular layer 1624 includes calcined coke with an average particle diameter of 18 mm, and the second lower resistance granular material
  • the resistance value of the layer 1624 is 450 ⁇ 600 ⁇ ;
  • the thicknesses of the first lower resistance particle layer 1622 and the second lower resistance particle layer 1624 are 18 cm and 15 cm respectively;
  • the lower section 1600 also includes a protective layer 1640 disposed under the lower resistive heating particle layer, the protective layer 1640 is a carbon black protective layer, the thickness of the carbon black protective layer is 700 mm, and the resistance value of the carbon black protective layer is ⁇ 1000 ⁇ ;
  • crucible section resistance particles 1440 are filled between the outer walls of the crucible 1420, and the average particle diameter of the particles is 18mm;
  • the upper resistive heating particle layer is sequentially laid with the first upper resistive particle layer 1822 (average particle diameter 18mm), the second upper resistive particle layer 1824 from the lower layer to the upper layer (that is, along the direction away from the crucible 1420). (average particle diameter 7mm), the third upper resistance particle layer 1826 (average particle diameter 3mm) and the fourth upper resistance particle layer 1828 (average particle diameter is 1mm); the first upper resistance particle layer 1822, the second upper resistance particle layer 1824, the thickness of the third upper resistive granular layer 1826, and the fourth upper resistive granular layer 1828 are 10 cm, 12 cm, 13 cm, and 14 cm, respectively;
  • the graphitization furnace equipment 1000 also includes an electrode section 1900, which is arranged between the electrode 1260 and the crucible section 1400, at a position corresponding to the crucible section 1400, and the electrode section 1900 is filled with electrode section resistance particles 1920 , the average particle diameter of the resistance particles 1920 in the electrode section is 1mm;
  • the granular layer mentioned above is granular calcined coke.
  • the graphene film prepared in this embodiment has a thickness of 100 ⁇ m, a density of 2.04 g/cm 3 , a thermal conductivity of 1556.9 W/mK, and a tensile strength of 64 MPa.
  • Preparation method the preparation method of embodiment 2 is the same as embodiment 1.
  • Graphitization furnace structure the graphitization furnace equipment 1000 of embodiment 2 is similar to embodiment 1, the difference is:
  • the average particle diameter of the first lower resistance granular layer 1622 is 0.5 mm; the average particle diameter of the second lower resistance granular layer 1624 is calcined coke with an average particle diameter of 8 mm; the first lower resistance granular material layer 1622, the second lower resistance granular layer The thickness of 1624 is 10cm and 8cm respectively;
  • the thickness of the carbon black protective layer is 600mm, and the resistance value of the carbon black protective layer is ⁇ 1000 ⁇ ;
  • the average particle diameter of the crucible segment resistance particles 1440 filled between the outer walls of the crucible 1420 is 8 mm;
  • the first upper resistive particle layer 1822 (average particle diameter 8mm), the second upper resistive particle layer 1824 (average particle diameter 5mm), the third upper resistive particle layer 1826 (average particle diameter 2mm) and the second upper resistive particle layer 1826 (average particle diameter 2mm)
  • Four upper resistance particle layers 1828 (average particle diameter is 0.5mm); the thicknesses of the first upper resistance particle layer 1822, the second upper resistance particle layer 1824, the third upper resistance particle layer 1826, and the fourth upper resistance particle layer 1828 are respectively 5cm, 8cm, 12cm, 15cm;
  • the electrode segment resistance particles 1920 filled in the electrode segment 1900 have an average particle diameter of 0.5 mm.
  • Preparation method the preparation method of embodiment 3 is the same as embodiment 1.
  • the structure of graphitization furnace is similar to embodiment 1, and difference is:
  • the first lower resistance particle layer 1622 includes calcined coke with an average particle diameter of 2 mm; the second lower resistance particle layer 1624 includes calcined coke with an average particle diameter of 30 mm; the first lower resistance particle material layer 1622, the second lower resistance particle layer
  • the thicknesses of the resistive particle layer 1624 are 25 cm and 20 cm, respectively;
  • the thickness of the protective layer 1640 is 800mm;
  • the average particle diameter of the crucible segment resistance particles 1440 filled between the outer walls of the crucible 1420 is 30 mm;
  • the first upper resistive particle layer 1822 (average particle diameter 30mm), the second upper resistive particle layer 1824 (average particle diameter 10mm), the third upper resistive particle layer 1826 (average particle diameter 4mm) and the second upper resistive particle layer 1826 (average particle diameter 4mm)
  • Four upper resistance granular layers 1828 (average particle diameter is 2mm); the thickness of the first upper resistance granular layer 1822, the second upper resistance granular layer 1824, the third upper resistance granular layer 1826, and the fourth upper resistance granular layer 1828 is 15cm respectively , 18cm, 20cm, 25cm;
  • the electrode segment resistance particles 1920 filled in the electrode segment 1900 have an average particle diameter of 2 mm.
  • the graphitization furnace equipment 1000 of embodiment 4 is similar to embodiment 1, the difference is:
  • the lower resistance heating particle layer also includes a third lower resistance particle layer 1626, the third lower resistance particle layer 1626 is laid on the lower layer of the first lower resistance particle layer 1622, and has an average particle diameter of 0.1mm, thickness 18cm;
  • a fifth upper resistive particle layer 1829 is also included.
  • the fifth upper resistive particle layer 1829 is disposed above the fourth upper resistive particle layer 1828, has an average particle diameter of 0.1 mm, and a thickness of 15 cm.
  • the baked reduced graphene oxide film and graphite paper into the graphite crucible, then stack the graphite crucible into the Acheson graphitization furnace, and adopt the staged power transmission and heating method for graphitization deal with.
  • the maximum power output is used to promote the current density in the furnace to quickly reach the heating condition, so that the furnace body can be freely heated to 1200 ° C and kept for 10 hours; in the second stage, the output power is adjusted Under the condition of full load and high current, the product is pulled up to 2100°C and kept warm for 10 hours.
  • the third stage is to quickly pull up the product to 2900°C under high current and keep warm for 3 hours by adjusting the output power.
  • the fourth stage The stage is to steadily increase the temperature to 3200°C under the stable output power of small current, and maintain the output power of small current for 5 hours after keeping warm.
  • the product realizes the repair and recrystallization of structural defects during the natural cooling process that lasts for 21 days to obtain a fluffy graphene film.
  • the arrangement of the carbon black protective layer and the resistance particle layer in the Acheson graphitization furnace is the same as that in Embodiment 1.
  • the graphene film prepared in this embodiment has a thickness of 65 ⁇ m, a density of 2.05 g/cm 3 , a thermal conductivity of 1478.5 W/mK, and a tensile strength of 55 MPa.
  • a kind of preparation method of graphene film comprises the following steps:
  • the baked reduced graphene oxide film and graphite paper into the graphite crucible, then stack the graphite crucible into the Acheson graphitization furnace, and adopt the staged power transmission and heating method for graphitization deal with.
  • the maximum power output is used to promote the current density in the furnace to quickly reach the heating condition, so that the furnace body can be freely heated to 1200 ° C and kept for 10 hours; in the second stage, the output power is adjusted Under the condition of full load and high current, the product is pulled up to 2100°C and kept warm for 10 hours.
  • the third stage is to adjust the output power to quickly pull the product up to 2900°C under high current and hold it for 3 hours.
  • the temperature was steadily increased to 3200°C under the stable output power of low current, and after maintaining the low current output power for 5 hours, the product achieved structural defect repair and recrystallization during the natural cooling process that lasted for 21 days to obtain a fluffy graphene film.
  • the arrangement of the carbon black protective layer and the resistance particle layer in the Acheson graphitization furnace is the same as that in Embodiment 1.
  • the graphene film prepared in this embodiment has a thickness of 198 ⁇ m, a density of 2.04 g/cm 3 , a thermal conductivity of 1309.4 W/mK, and a tensile strength of 55 MPa.
  • a kind of preparation method of graphene film comprises the following steps:
  • the special substrate is immersed in the graphene oxide slurry, and the graphene oxide slurry is evenly attached to the substrate by pulling at a certain rate, and the graphene oxide film is obtained after drying and demolding;
  • the baked reduced graphene oxide film and graphite paper into the graphite crucible, then stack the graphite crucible into the Acheson graphitization furnace, and adopt the staged power transmission and heating method for graphitization deal with.
  • the maximum power output is used to promote the current density in the furnace to quickly reach the heating condition, so that the furnace body can be freely heated to 1200 ° C and kept for 8 hours;
  • the second stage is to adjust the output power Under the condition of full load and high current, the product is pulled up to 2100°C and held for 9 hours.
  • the third stage is to adjust the output power to quickly pull the product up to 2900°C under the condition of high current and hold for 5 hours.
  • the temperature was steadily increased to 3200°C under the stable output power of low current, and after maintaining the low current output power for 8 hours, the product achieved structural defect repair and recrystallization during the natural cooling process that lasted for 21 days to obtain a fluffy graphene film.
  • the cooling process is to use a negative pressure vacuum cleaner to evenly absorb the laid resistance particles, so that the resistance particles are removed, and the layers are exposed to the air to realize the natural cooling process.
  • the uppermost resistance particles are removed layer by layer through artificial interference to realize the cooling time. adjustable.
  • the graphitized fluffy graphene film is subjected to compaction and densification treatment under a pressure of 50 MPa to obtain a graphene film.
  • the arrangement of the carbon black protective layer and the resistance particle layer in the Acheson graphitization furnace is the same as that in Embodiment 1.
  • the graphene film prepared in Embodiment 4 has a thickness of 120 ⁇ m, a density of 1.95 g/cm 3 , a thermal conductivity of 1302.8 W/mK, and a tensile strength of 53 MPa.
  • the graphene film prepared in this comparative example has a thickness of 100 ⁇ m, a density of 2.03 g/cm 3 , a thermal conductivity of 996.7 W/mK, and a tensile strength of 42 MPa.
  • step (4) The difference between the preparation method of Comparative Example 2 and Example 1 is that the heat treatment conditions of step (4) are: to obtain a fluffy graphene film with 2800 ° C for 30 min;
  • the electrode section 1900 is filled with electrode section resistance particles 1920, and the average particle diameter of the electrode section resistance particles 1920 is 18mm.
  • step (4) The difference between the preparation method of Comparative Example 3 and Example 1 is that the heat treatment conditions of step (4) are: to obtain a fluffy graphene film with 2800 ° C for 30 min;
  • the lower section 1600 also includes a protective layer 1640 disposed under the lower resistive heating particle layer, the protective layer 1640 is a carbon black protective layer, the thickness of the carbon black protective layer is 700 mm, and the resistance value of the carbon black protective layer is ⁇ 1000 ⁇ .
  • step (4) The difference between the preparation method of Comparative Example 4 and Example 1 is that the heat treatment conditions of step (4) are: to obtain a fluffy graphene film with 2800 ° C for 30 min;
  • the average particle size is 2 mm, and the thickness is 33 cm;
  • the average particle size is 2 mm, and the thickness is 49 cm;
  • the electrode section 1900 is filled with electrode section resistance particles 1920, and the average particle diameter of the electrode section resistance particles 1920 is 2 mm.
  • Table 1 is the performance parameter table of Examples 1-7 and Comparative Examples 1-4 of the present disclosure
  • Example 1 100 2.04 1556.9 64
  • Example 2 105 2.10 1520.5 60
  • Example 3 98 2.18 1604.8 58
  • Example 4 96 2.16 1568.5 62
  • Example 5 65 2.05 1478.5 55
  • Example 6 198 2.04 1309.4 55
  • Example 7 120 1.95 1302.8 53
  • Comparative example 1 100 2.03 996.7 42
  • Comparative example 2 96 1.98 1120.5 29 Comparative example 3 98 2.09 950.6 37
  • the graphene film prepared in Example 1 has a thermal conductivity significantly higher than that of Comparative Example 1, and has excellent thermal conductivity; while the tensile strength of the graphene film of Example 1 is significantly higher than Comparative example 1 has excellent mechanical properties.
  • the graphene film prepared in Examples 2-7 is similar to Example 1 in structure and performance.
  • the reduced graphene oxide film is graphitized using an Acheson graphitization furnace, wherein the resistive heating particles (resistive particles) in the Acheson graphitization furnace and the reduced graphene oxide film in the crucible together constitute a furnace Resistance, by applying current, the resistance heating particles (resistor particles) and the graphene oxide film will generate co-heating to achieve a very high graphitization temperature, thanks to the resistance heating particles (resistance particles) of different particle sizes buried around the crucible, The core graphitization temperature in the crucible remains stable, which can realize the natural and slow cooling of the resistance particles in the process of cooling the resistance particles.
  • the resistance heating particles resistor particles
  • the resistance heating particles are slowly and alternately removed to further make the graphene film
  • the recrystallization of the structure is realized to generate large-area crystal domains, which improves the thermal and mechanical properties of the graphene film.
  • Comparative example 1 adopts the graphitization temperature working limit of the electromagnetic induction heating method to be 2900 °C, and the holding time of the limit working temperature is short, and the graphitization temperature of the reduced graphene oxide film cannot exceed 3000 °C, resulting in the electrical properties of the graphene film obtained. , thermal and mechanical properties have declined. Moreover, due to the structural design requirements of the electromagnetic induction graphitization furnace, cooling water must be used to rapidly cool the electromagnetic induction coil after stopping heating to avoid serious aging of the core components. It is difficult to achieve perfect repair of the graphene film structure during the accelerated cooling process, and the degree of crystal orientation Poor, which limits the electrical, thermal, and mechanical properties of graphene films.
  • the heating method of the electromagnetic induction graphitization furnace is to generate a magnetic field through a high-voltage current, the magnetic field generates an induced current in the conductor, thereby causing the conductor to heat up.
  • the conductor must be high-purity or isostatic pressure Graphite crucible, the graphene oxide film is placed in the above crucible, and the graphitization temperature is driven by the crucible's own heating.
  • comparative examples 2-4 cannot realize the long-term preparation of segmented high temperature in the present disclosure, because this preparation method will cause cracking, bursting and even bursting of the furnace body in the heating section, causing potential safety hazards, so comparative examples 2-4 Only high temperature and short time preparation can be selected.
  • Table 1 it can be seen from Table 1 that the thermal conductivity and mechanical properties of the graphene prepared in Comparative Examples 2-4 are far lower than those of the graphene film prepared in the present disclosure.
  • the graphene film prepared by embodiment 1-7 has thermal conductivity significantly higher than that of comparative example 2-4, and has excellent thermal conductivity; the tensile strength of the graphene film of embodiment 1-7 is significantly higher than that of comparative example 2 -4, has excellent mechanical properties.
  • the graphene film provided by the present disclosure and its preparation method, the preparation method of the present disclosure can reduce the production cost, simplify the preparation process, and greatly improve the thermal conductivity of the graphene film; at the same time, the structural defects of the graphene film product provided by the present disclosure are in It can be perfectly repaired under the ultra-high temperature graphitization temperature and the ultra-long graphitization heat preservation process. It has excellent thermal and mechanical properties, and has a wide range of practical value and practical performance.

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Abstract

本公开提供一种石墨烯膜及其制备方法，所述方法包括以下步骤：将还原氧化石墨烯膜放入艾奇逊石墨化炉中，进行不同阶段的高温热处理后自然降温，得到结构缺陷修复和重结晶的蓬松石墨烯膜，其中，所述艾奇逊石墨化炉内含有电阻发热颗粒(电阻颗粒)，所述艾奇逊石墨化炉的加热方式为施加电流使其流经所述电阻发热颗粒，使得所述电阻发热颗粒发热升温达到石墨化温度，以加热所述还原氧化石墨烯膜；将所述蓬松石墨烯膜进行压实致密化处理，得到石墨烯膜。本公开提供的一种石墨烯膜的制备方法，能够降低生产成本，简化制备工艺，大幅度提高石墨烯膜的热传导性能。

Description

石墨烯膜及其制备方法
相关申请的交叉引用
本公开要求于2021年08月06日提交中国专利局的申请号为CN202110899606.3，名称为“石墨烯膜及其制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本公开中。
技术领域
本公开涉及石墨材料技术领域，具体地讲，涉及一种石墨烯膜及其制备方法。
背景技术
石墨烯膜因其出色的热传导和导电性能，受到市场越来越多的关注。特别是随着电子工业的快速发展，电子产品日趋高度集成化，导致电器设备的散热成为亟待解决的问题，电器设备的可靠性会随着热量的堆积而下降。因此鉴于石墨烯的卓越的热学和电学性能，有望可以开发成为未来主流功能型电子材料。
目前石墨烯膜的批量制备都是采用氧化石墨烯或氧化石墨作为原材料，通过抽滤、浸涂、旋涂、喷涂、蒸发及涂布等方法成型得到氧化石墨烯膜，再经过石墨化后得到的。通常最常用的石墨化方法是采用电磁感应石墨化炉，也是目前商用合成石墨导热膜最常用的石墨化方法。常规的电磁感应石墨化炉由于炉体保温材料的寿命短、性能中庸、安装复杂等问题造成了石墨化温度和保温时间随使用次数的增加而急剧下降，一方面为了保证设备整体使用寿命，故仅能将电磁感应石墨化炉限制在2600‐2900℃区间操作，使得其无法满足还原氧化石墨烯膜所需达到的高温热处理温度；另一方面由于电磁感应石墨化炉自身寿命短、性能下降快等问题，也无法满足石墨烯膜的制备要求。并且由于石墨烯膜是通过将氧化石墨烯膜进行碳化和石墨化得到的，氧化石墨烯膜含有的大量含氧官能团会随着温度的升高发生分解，造成电磁感应石墨化炉体材料如石墨坩埚、碳毡保温材、炉壁等的氧化，促使电磁感应石墨化炉的使用寿命进一步降低，造成产品的整体生产成本增加。针对于此种情况，开发一种低成本、大批量同时可以大幅度提升产品性能的石墨化制备方法势在必行。
发明内容
本公开提供了一种石墨烯膜的制备方法，所述方法包括以下步骤：
将还原氧化石墨烯膜放入艾奇逊石墨化炉中，进行不同阶段的高温热处理使得所述还原氧化石墨烯膜达到石墨化温度，自然降温得到蓬松石墨烯膜；
将所述蓬松石墨烯膜进行压实致密化处理，得到石墨烯膜。
可选地，将所述还原氧化石墨烯膜置于所述艾奇逊石墨化炉内的坩埚中，所述艾奇逊石墨化炉内的坩埚之间与坩埚表面均铺设填埋电阻颗粒，所述电阻颗粒发热升温至石墨化温度；所述电阻颗粒的平均粒径范围为0至30mm，且不包括0mm。
可选地，将所述还原氧化石墨烯膜与石墨纸层叠后放入所述艾奇逊石墨化炉内的坩埚中，所述艾奇逊石墨化炉内的坩埚之间与坩埚表面均铺设填埋电阻发热颗粒，所述电阻发热颗粒发热升温至石墨化温度；所述电阻发热颗粒包括不同粒径的煅后焦，所述煅后焦的平均粒径范围为0至30mm，且不包括0mm。
可选地，位于所述坩埚下方的艾奇逊石墨化炉的炉腔内由上层至下层依次铺设有电阻颗粒层和保护层；位于所述坩埚上方的艾奇逊石墨化炉的炉腔内铺设有电阻颗粒层。
可选地，位于所述坩埚下方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括至少两层，且各层所述电阻颗粒层的颗粒平均粒径由上层至下层逐层递减。
可选地，位于所述坩埚上方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括至少四层，且各层所述电阻颗粒层的颗粒平均粒径由下层至上层逐层递减。
可选地，位于所述坩埚下方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括两层，包括由上层至下层依次铺设颗粒的平均粒径范围在8mm～30mm和小于等于2mm的电阻颗粒层。
可选地，位于所述坩埚上方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括四层，包括由下层至上层依次铺设颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm以及小于等于2mm的电阻颗粒层。
可选地，所述电阻颗粒包括煅后石油焦、生石油焦和炭黑中的至少一种。
可选地，所述还原氧化石墨烯膜中的挥发组分低于10wt％。
可选地，所述石墨化温度范围为3000℃～3200℃。
可选地，所述高温热处理中的热处理周期为10天～30天。
可选地，采用分段式升温至所述石墨化温度。
可选地，所述高温热处理包括：
第一阶段，将所述艾奇逊石墨化炉温度升温至1000℃～1400℃，保温5h～10h；
第二阶段，将所述艾奇逊石墨化炉内温度继续升温至2000℃～2100℃，保温5h～10h；
第三阶段，将所述艾奇逊石墨化炉内温度继续升温至2800℃～2900℃，保温2h～5h，再继续升温至3000℃～3200℃，保温5h～10h；
停止送电，将艾奇逊石墨化炉自然降温，得到蓬松石墨烯膜。
可选地，所述蓬松石墨烯膜的压实压强为2MPa～100MPa。
可选地，在将还原氧化石墨烯膜放入艾奇逊石墨化炉中之前，所述方法还包括；
将氧化石墨烯膜进行烘烤，得到还原氧化石墨烯膜。
可选地，氧化石墨烯膜由含氧化石墨烯或氧化石墨的浆料制备得到。
可选地，所述含氧化石墨烯或者所述氧化石墨的浆料浓度为1mg/mL～80mg/mL。
可选地，所述含氧化石墨烯或者所述氧化石墨的浆料通过以下的任意一种方式来混合获得：超声、机械剪切剥离、机械搅拌及高压均质。
可选地，所述氧化石墨烯膜的制备工艺包括抽滤工艺、浸涂工艺、旋涂工艺、喷涂工艺、蒸发工艺及涂布工艺中的任意一种方式。
可选地，所述烘烤的温度为150℃～550℃。
可选地，所述烘烤的升温速率为0.5℃/h～10℃/h。
可选地，所述烘烤的保温时间为5h～50h。
本公开提供一种石墨烯膜，所述石墨烯膜通过上文所述的制备方法制得。
可选地，所述石墨烯膜的厚度为10μm～300μm。
可选地，所述石墨烯膜的密度为1.8g/cm 3～2.3g/cm 3。
可选地，所述石墨烯膜的导热系数为1300W/mK～1600W/mK。
可选地，所述石墨烯膜的拉伸强度为50MPa～65MPa。
本公开提供一种电子设备，所述电子设备包含如上文任一项所述的石墨烯膜的制备方法制得的石墨烯膜或上文所述的石墨烯膜。
本公开还提供了一种石墨化炉设备，包括：
石墨化炉主体，包括炉壁、由炉壁包围构成的炉腔、和电极；
坩埚区段，设置在炉腔内与电极对应的位置，包括多个坩埚和填充在坩埚周围的坩埚区段电阻颗粒；
下区段，设置坩埚区段下方炉腔内，包括下电阻颗粒层；以及
上区段，设置坩埚区段上方炉腔内，包括上电阻颗粒层。
可选地，所述下区段的下端还设置有保护层。
可选地，所述电阻颗粒的平均粒径范围为0至30mm，且不包括0mm。
可选地，所述石墨化炉设备为用于生产石墨烯膜的艾奇逊石墨化炉。
可选地，所述坩埚内铺设有还原氧化石墨烯膜。
可选地，所述下电阻颗粒层包括至少两层，且各层所述电阻颗粒层的颗粒平均粒径由上层至下层逐层递减。
可选地，所述上电阻颗粒层包括至少四层，且各层所述电阻颗粒层的颗粒平均粒径由下层至上层逐层递减。
可选地，所述下电阻颗粒层包括两层，包括由上层至下层依次铺设颗粒的平均粒径范围在8mm～30mm和小于等于2mm的电阻颗粒层。
可选地，所述上电阻颗粒层包括四层，包括由下层至上层依次铺设颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm以及小于等于2mm的电阻颗粒层。
可选地，所述坩埚区段电阻颗粒的平均粒径为8mm～30mm。
可选地，所述石墨化炉设备还包括电极区段。
可选地，所述石墨化炉设备还包括电极区段，电极区段设置在所述电极和所述坩埚区段之间、与所述坩埚区段对应的位置。
可选地，所述电极区段中填充有电极区段电阻颗粒。
可选地，所述电极区段电阻颗粒的平均粒径为≤2mm。
可选地，所述电阻颗粒包括煅后石油焦、生石油焦或炭黑中的至少一种。
本公开还提供了上文所述的电子设备或者上文任一项所述的石墨化炉设备用于制备石墨烯膜的用途。
附图说明
图1为本公开实施例提供的石墨烯膜的制备方法流程图；
图2为本公开一些实施方式提供的艾奇逊石墨化炉内的结构示意图；
图3为本公开一些实施方式提供的艾奇逊石墨化炉内的结构示意图；
图4为本公开一些实施方式提供的艾奇逊石墨化炉内的结构示意图；
图5为本公开一些实施方式提供的艾奇逊石墨化炉内的结构示意图；
图6a实施例1制得的石墨烯膜的SEM图；
图6b实施例5制得的石墨烯膜的SEM图；
图6c实施例6制得的石墨烯膜的SEM图；
图6d实施例7制得的石墨烯膜的SEM图；
图6e为对比例1制得的石墨烯膜的SEM图。
附图标记：
1000-石墨化炉设备、1200-艾奇逊石墨化炉主体、1220-炉壁、1240-炉腔、1260-电极、1400-坩埚区段、1420-坩埚、1440- 坩埚区段电阻颗粒、1460-还原氧化石墨烯膜、1600-下区段、1620-下电阻颗粒层、1622-第一下电阻颗粒层、1624-第二下电阻颗粒层、1626-第三下电阻颗粒层、1640-保护层、1800-上区段、1820-上电阻颗粒层、1822-第一上电阻颗粒层、1824-第二上电阻颗粒层、1826-第三上电阻颗粒层、1828-第四上电阻颗粒层、1829-第五上电阻颗粒层、1900-电极区段、1920-电极区段电阻颗粒。
具体实施方式
以下所述是本公开实施例的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本公开实施例原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本公开实施例的保护范围。
定义
为了促进对本公开的原理和技术内容的理解，本公开选择使用特定语言对其进行描述。然而，应当理解，以下定义并不旨在限制本公开的范围。
如本文所用，术语“蓬松石墨烯膜”是指石墨烯膜的结构呈现松散多孔、不密实的外观结构，并且可以和术语“多孔状蓬松石墨烯膜”互换使用。如本文所用，术语“压实压强”是指将蓬松石墨烯膜进行压实达到真实密度的压强，并且可以和术语“压实强度”互换使用。
如本文所用，术语“平均粒径”是指通过材料的表面所测定的粒子的的数均粒径，例如可以通过测量平均粒径的仪器(诸如平均粒度测量仪)测量而得到平均粒径，即反映出的材料的平均粒径。
发明人经研究发现，由于石墨烯膜是由小片层石墨烯(≤3μm)堆叠而成，提升石墨化过程最高温度以及延长降温时间可以促使小片层石墨烯片结晶重组成大片层石墨烯片，进而导热性能以及结构强度都可以大幅度提高，因此需要一种可以稳定达到3000℃以上的石墨化工艺，同时兼具缓慢的降温速率，并且不受升温过程中产生的挥发物影响。
I.制备方法及石墨化炉设备(arrangement)
本公开一实施方式提供一种石墨烯膜的制备方法，所述方法包括以下步骤：
将还原氧化石墨烯膜放入艾奇逊石墨化炉中，进行不同阶段的热处理最终达到石墨化温度，自然降温得到蓬松石墨烯膜；
将所述蓬松石墨烯膜进行压实致密化处理，得到石墨烯膜。
本公开一实施方式提供一种石墨烯膜的制备方法，所述方法包括以下步骤：
将含氧化石墨烯或氧化石墨的浆料制备得到的氧化石墨烯膜进行烘烤，得到还原氧化石墨烯膜；
将所述还原氧化石墨烯膜放入艾奇逊石墨化炉(Acheson furnace)中，进行不同阶段的高温热处理使得所述还原氧化石墨烯膜达到石墨化温度，自然降温得到蓬松石墨烯膜。
在一些实施方式中，高温热处理范围为1000℃～3200℃。
在本实施方式中，将部分还原氧化石墨烯膜放入艾奇逊石墨化炉内，艾奇逊石墨炉内的电阻发热颗粒(电阻颗粒)与部分还原氧化石墨烯膜共同构成炉阻，通过施加电流，使电流流经炉内电阻发热颗粒(电阻颗粒)以及部分还原氧化石墨烯膜后产生巨大热能，使部分还原氧化石墨烯膜获得石墨化所需热量，实现产品的石墨化，由于电阻发热颗粒(电阻颗粒)以及还原氧化石墨烯膜在施加大电流下产生的共热现象使艾奇逊石墨化炉内的石墨化温度保持极高水平且持续时间长，使石墨烯膜产品的结构缺陷在超高的石墨化温度以及超长保温时间下得以完美修复，同时得益于坩埚周边填埋不同粒径的电阻发热颗粒(电阻颗粒)，坩埚内的核心石墨化温度保持稳定，可以实现在电阻颗粒降温的过程中的自然缓慢降温，在后续将电阻颗粒降温期间，通过缓慢交替移除电阻发热颗粒(电阻颗粒)，进一步使石墨烯膜在漫长的降温过程(20天至30天)中实现结构的重新结晶生成大面积晶畴，使产品的电学、热学、力学性质提高。相较于其他石墨化热处理办法如电磁感应方式进行石墨化，采用艾奇逊石墨化炉进行石墨化的方法更简单、易于实现、批量生产可靠且故障率极低。且由于艾奇逊石墨化炉的长期使用可靠性强、故障率低、石墨化程度高、工艺简单等，不仅降低了石墨烯膜的整体制造成本，同时使材料性能得到了大幅度提升。
图1为本公开实施例提供的石墨烯膜的制备方法流程图，结合图1所示，以下介绍本实施方式：
步骤S10，将含氧化石墨烯或氧化石墨的浆料制备得到的氧化石墨烯膜进行烘烤，得到还原氧化石墨烯膜。
在一些实施方式中，可以将氧化石墨烯或者氧化石墨加入溶剂中制成浆料，所述含氧化石墨烯或者所述氧化石墨的浆料通过超声、机械剪切剥离、机械搅拌、高压均质中的任意一种方式混合获得。
所述氧化石墨烯膜的制备工艺包括抽滤工艺、浸涂工艺、旋涂工艺、喷涂工艺、蒸发工艺及涂布工艺中的任意一种方式获得。示例性地，可以将浆料经过涂布、干燥，制成氧化石墨烯膜。
在一些实施方式中，所述浆料的浓度为1mg/mL～80mg/mL，例如5mg/mL～80mg/mL、10mg/mL～70mg/mL或20mg/mL～60mg/mL，在一些实施方式中，浆料的浓度可以是1mg/mL、5mg/mL、10mg/mL、15mg/mL、20mg/mL、30mg/mL、40mg/mL、50mg/mL、60mg/mL、70mg/mL或80mg/mL等，当然也可以是上述范围内的其他值，在此不做限定。需要说明的是浆料的浓度是指单位溶剂中所含有的溶质的量，溶质可以是氧化石墨烯和/或氧化石墨，在此不做限定。
配置好浆料后，还需要对浆料进行分散处理，分散处理包括超声分散、机械剪切剥离分散、机械搅拌分散、高压均质分散中的至少一种。
作为本公开可选的实施方式，所述烘烤温度为150℃～550℃，例如200℃～550℃、250℃～500℃或300℃～400℃，升温速率为0.5-10℃/h，例如1-10℃/h、1-5℃/h或1.5-4.5℃/h；具体可以是150℃、200℃、250℃、300℃、350℃、400℃、450℃、500℃或550℃等等，升温速率可以是0.5℃/h、1℃/h、1.5℃/h、2℃/h、2.5℃/h、3℃/h、3.5℃/h、4℃/h、4.5℃/h、5℃/h当然也可以是上述范围内的其他值，在此不做限定。
可以理解地，氧化石墨烯膜由于含有大量的水分以及含氧化学官能团(如羟基/羧基/环氧基等)，需要在做高温石墨化处理之前去除水分及含氧化学官能团。通过缓慢烘烤，可以将氧化石墨烯膜中含有的大部分水分及含氧化学官能团去除，从而避免氧化石墨烯膜在后续高温热处理过程中，可能由于水分或含氧化学官能团等易于挥发物的急速挥发导致石墨烯膜的内腔压强的增大，不仅不利于后期结晶，甚至可能导致炸裂，方便后续的石墨化处理。
作为本公开可选的实施方式，所述烘烤后的氧化石墨烯膜中的挥发组分低于(小于等于)10wt％，例如，1～10wt％、2～9wt％或3～6wt％，具体可以是9wt％、8wt％、7wt％、6wt％、5wt％、4wt％、3wt％、2wt％或1wt％等等，当然也可以是上述范围内的其他值，在此不做限定。
通过控制烘烤后的氧化石墨烯膜中的挥发组分的含量，可以避免氧化石墨烯膜在后续的石墨化过程中由于易挥发组分如水、羟基、羧基、环氧基等化学官能团的去除不干净，使膜内部在高温下由于瞬时挥发产生的巨大压强导致膜爆裂，石墨烯膜损毁。
可以理解的是，本步骤可以省略，可以直接选用符合上述条件的还原氧化石墨烯膜，即选用挥发组分低于10wt％的还原氧化石墨烯膜。
步骤S20，将所述还原氧化石墨烯膜放入艾奇逊石墨化炉中，进行不同阶段的高温热处理使得所述还原氧化石墨烯膜达到石墨化温度，自然降温得到蓬松石墨烯膜。
在一些实施方式中，电阻发热颗粒(电阻颗粒)包括但不限于煅后石油焦、生石油焦或炭黑中的至少一种。
在一些实施方式中，可以将所述还原氧化石墨烯膜与石墨纸层叠后放入所述艾奇逊石墨化炉内的坩埚中，所述艾奇逊石墨化炉内的坩埚之间与坩埚表面均铺设填埋所述电阻发热颗粒(电阻颗粒)。所述艾奇逊石墨化炉的加热方式为施加电流使其流经所述电阻发热颗粒(电阻颗粒)，使得所述电阻发热颗粒(电阻颗粒)发热升温达到石墨化温度，以加热所述还原氧化石墨烯膜。所述电阻发热颗粒(电阻颗粒)包括不同粒径的煅后焦，所述煅后焦的平均粒径范围为0至30mm，且不包括0mm。
在本实施方式中，坩埚为定制的矩形坩埚，坩埚尺寸可以根据石墨烯膜的尺寸进行定制，使坩埚内空间利用最大化。
本公开一实施方式提供一种石墨化炉设备，包括：
石墨化炉主体，包括炉壁、由炉壁包围构成的炉腔、和电极；
坩埚区段，设置在炉腔内与电极对应的位置，包括多个坩埚和填充在坩埚周围的坩埚区段电阻颗粒；
下区段，设置坩埚区段下方炉腔内，包括下电阻颗粒层；以及
上区段，设置坩埚区段上方炉腔内，包括上电阻颗粒层。
在一些实施方式中，下区段的下端还设置有保护层。
在一些实施方式中，电阻颗粒的平均粒径范围为0至30mm，且不包括0mm。
在一些实施方式中，坩埚内铺设有还原氧化石墨烯膜。
在一些实施方式中，该石墨化炉主体为艾奇逊石墨化炉主体。
本公开的石墨化炉中是通过输入大电流低电压的方式，电流流入电阻发热颗粒(电阻颗粒)之后，电阻发热颗粒(电阻颗粒)以其自身电阻来产生热量，并且与还原氧化石墨烯膜共同构成炉阻，使电流流经炉内电阻发热颗粒(电阻颗粒)和还原氧化石墨烯膜后产生共热，电阻发热颗粒(电阻颗粒)的电阻对于温度的控制极其重要，电阻如何的排布和匹配对于所要满足的温度要求主要需要不同电阻值的电阻发热颗粒(电阻颗粒)和不同颗粒大小的电阻发热颗粒(电阻颗粒)，并不是通过单一添加某种电阻发热颗粒(电阻颗粒)或者直接通过本领域已知的技术就可以实现的。本公开的电阻发热颗粒(电阻颗粒)排布，不仅可以实现所需的高温，而且有效保持了内部炉阻的统一、均匀和稳定。
参照附图2，本公开还提供一种石墨化炉设备(arrangement)1000，包括：
艾奇逊石墨化炉主体1200，包括炉壁1220、由炉壁1220包围构成的炉腔1240和电极1260；
坩埚区段(section)1400，设置在炉腔1240内与电极1260对应的位置，包括多个坩埚1420和填充在坩埚1420周围的坩埚区段电阻颗粒；
下区段(up section)1600，设置坩埚区段1400下方炉腔1240内，包括下电阻颗粒层1620；以及
上区段(down section)1800，设置坩埚区段1400上方炉腔1240内，包括上电阻颗粒层1820。
在本公开中，下电阻颗粒层也称为坩埚下方的电阻颗粒层。上电阻颗粒层也称为坩埚上方的电阻颗粒层。
在一些实施方式中，坩埚内铺设有还原氧化石墨烯膜1460。
在现有技术中，常规的艾奇逊石墨化炉，基本用于生产石墨材料等，众所周知，艾奇逊石墨化炉在超高温、长时生产的过程中，电阻料因高温石墨化膨胀，由于被处理的石墨材料在结构上属于实心块体结构，且在装载石墨材料的加热区段中，材料可以填满加热区段而不留空隙，而加热区段由于无空隙则不会引发因电阻料膨胀而造成的加热区段膨胀开裂、爆裂甚至是整个炉体的爆裂，生产可以顺利进行。
而现有技术却从未公开过利用艾奇逊石墨化炉制备石墨烯膜的技术，这是因为现有技术无法克服以下的技术难题和缺陷：由于生产的材料为膜材料，该膜材料本身并不属于实心体结构，且在装载有膜材料的加热区段中，膜材料由于无法填满加热区段的，膜和膜之间势必会存在多空隙的问题，则在超高温、长时生产的过程中，常规的电阻颗粒(电阻发热颗粒)因高温石墨化膨胀会挤压装载膜材料的坩埚最终导致加热区段坩埚的开裂、爆裂甚至是炉体的爆裂。而本公开提供的石墨化炉设备1000却可以突破该技术难题和缺陷，实现在超高温、长时生产的条件下，生产石墨烯膜。本公开生产石墨烯膜的石墨化炉设备1000是基于常规的艾奇逊石墨化炉进行了改进，对加热和保温结构进行特殊设置，在一些实施方式中是通过以下实现 的。
(A)下区段：位于坩埚下方的艾奇逊石墨化炉炉腔内的铺设组成
参照附图3，在一些实施方式中，下区段1600还包括设置在下电阻颗粒层下方的保护层1640。
在一些实施方式中，位于坩埚1420下方的艾奇逊石墨化炉主体1200的炉腔1240内由上层至下层(即沿着远离坩埚1420的方向)依次铺设有下电阻颗粒层和保护层1640。据信，不受理论的约束，电阻颗粒通过不同的粒径来控制电阻颗粒的电阻值。
在一些实施方式中，保护层1640的厚度可以为500mm～900mm，例如可以为500mm～600mm、600mm～900mm、600mm～800mm，诸如500mm、600mm、700mm、800mm、900mm。在一些实施方式中，保护层1640的电阻值≥1000μΩ。在一些实施方式中，保护层1640为炭黑保护层。本公开的保护层电阻在上述范围内，使得在加热过程中，电流不会首先流经保护层，同时本公开保护层的电阻和厚度在上述范围内使得保护层起到良好的保温作用，同时具备优异的耐温性，保护炉底在3000℃及以上时不会被烧穿，从而进一步提高炉内整体的隔热保温作用。
在一些实施方式中，下电阻颗粒层1620可以包括至少两层。在一些实施方式中，下电阻颗粒层1620的颗粒平均粒径由上层至下层(即沿着远离坩埚1420的方向)逐层递减。
在本公开下电阻颗粒层的粒径排布，电流首先流经电阻颗粒层的平均粒径相对较小(即电阻相对较小)的较下层的电阻颗粒层，该电阻颗粒层的平均粒径相对较小，分布更为密实，电流的输入更加持续稳定，因此电阻颗粒层可以持续稳定发热，并且起到良好的保温作用，延长石墨化保温时间，减小与空气直接的热交换，起到良好的隔绝空气的作用，进而提高产品的石墨化率；电流之后流经颗粒相对较大(即电阻相对较大)的较上层的电阻颗粒层，使得该层电阻颗粒持续发热，但是该颗粒层的粒径相对较大，即电阻相对较大，进而该电阻颗粒不会因为过度加热而产生上文所述的过度膨胀，从而保证了石墨化的高效进行。
随着电阻颗粒的加热过程(即石墨化过程)持续，电阻颗粒的电阻值(电阻率)慢慢变小，使得电流持续流通，进而电流继续流经上区段(下文所述)，从电阻颗粒层的平均粒径由小至大的方向依次流经，同理在上区段，电阻颗粒的加热过程循环渐进。
本公开下电阻颗粒层的粒径排布，是为了有效发挥远离坩埚端的颗粒层的加热和主要的保温、延长石墨化保温时间、隔绝空气作用；以及靠近坩埚端的颗粒层的加热作用，同时避免该颗粒的过度加热，有效抑制了电阻颗粒的膨胀，从而避免了坩埚破裂。
参照附图3，在一些实施方式中，下电阻颗粒层1620包括：第一下电阻颗粒层1622和第二下电阻颗粒层1624，其中第二下电阻颗粒层1624设置在坩埚1420底部下方，第一下电阻颗粒层1622设置在第二下电阻颗粒层1624下方。
在一些实施方式中，第一下电阻颗粒层1622具有颗粒的平均粒径范围在大于0且小于等于2mm，例如0.1mm～1.8mm，0.5mm～1.5mm，或1mm～1.3mm。在一些实施方式中，第一电阻颗粒料层的电阻值为450μΩ～600μΩ，例如480μΩ～580μΩ，500μΩ～550μΩ，或510μΩ～530μΩ。在一些实施方式中，第二下电阻颗粒层1624具有颗粒的平均粒径范围在8mm～30mm，例如10mm～25mm，12mm～20mm，或15mm～18mm。在一些实施方式中，第二下电阻颗粒层1624的电阻值为450μΩ～600μΩ，例如480μΩ～580μΩ，500μΩ～550μΩ，或510μΩ～530μΩ。在一些实施方式中，第一下电阻颗粒层1622的厚度为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。在一些实施方式中，第二下电阻颗粒层1624的厚度为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。在一些实施方式中，坩埚1420下方的电阻颗粒层的总厚度为10cm～50cm，或15cm～40cm，或16cm～30cm，或10cm～25cm。在一些实施方式中，第一下电阻颗粒层1622和第二下电阻颗粒层1624包括煅后焦或由煅后焦组成。
本公开通过的下电阻颗粒层在上述不同粒径范围的分布组合，不仅实现了超高温、长时加热的稳定条件，而且并未因装载被处理膜材料之间的存在缝隙而出现加热区段(坩埚区段)或者整个炉体的破裂。本公开提供的下电阻颗粒层的组合，在加热过程中，发热颗粒膨胀得以抑制，故并未引发上述坩埚内存在的间隙导致坩埚被环绕的发热颗粒因发热膨胀挤压坩埚导致坩埚整体坍塌破裂。。
本公开第二下电阻颗粒层在上述粒径范围内，起到加热作用并且有效抑制电阻颗粒膨胀，第二下电阻颗粒层起到加热和主要的保温覆盖作用和隔绝空气的作用，本公开通过对粒径不同的电阻颗粒的特定排布，获得了稳定高温，保温，隔绝空气的特性，并且防止了因颗粒膨胀而引发的上述问题。
同时本公开在靠近坩埚处的颗粒层(如第二下电阻颗粒层)平均粒径的范围了避免了粒径过小，导致的高温石墨化膨胀，颗粒容易挤压坩埚导致破裂，还避免了平均粒径过大，而造成的电流流经颗粒发热不均匀，且容易进入空气，达不到保温效果，和超高石墨化温度3000℃以上。
在一些实施方式中，下电阻颗粒层1620还包括第三下电阻颗粒层，其设置在第一下电阻颗粒层1622下方。在一些实施方式中，第三下电阻颗粒层的平均粒径范围大于0且小于等于0.5mm，例如0.1mm、0.2mm、0.3mm、0.4mm、0.5mm。在一些实施方式中，第三下电阻颗粒料层的厚度为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。上述第三下电阻颗粒层的增加以及额外的下电阻颗粒层1620的增加是可以根据保温时间需求和降温需求选择性增加，可以进一步提高保温、隔绝空气的作用。
在一些实施方式中，下电阻颗粒层1620还包括第四下电阻颗粒层，其设置在第三下电阻颗粒层的下方。在一些实施方式中，第四下电阻颗粒层的平均粒径范围大于0且小于等于0.5mm，例如0.1mm、0.2mm、0.3mm、0.4mm、0.5mm。
在一些实施方式中，下电阻颗粒层1620还包括第五下电阻颗粒层，其设置在第四下电阻颗粒层的下方。在一些实施方 式中，第五下电阻颗粒层的平均粒径范围大于0且小于等于0.5mm，例如0.1mm、0.2mm、0.3mm、0.4mm、0.5mm。在一些实施方式中，下电阻颗粒层1620的电阻值为450μΩ～600μΩ。在一些实施方式中，下电阻颗粒层1620包括两层或由两层组成，由上层至下层(即沿着远离坩埚1420的方向)依次铺设有具有颗粒的平均粒径范围在8mm～30mm和小于等于2mm的电阻颗粒层。
在一些实施方式中，下电阻颗粒层包括三层或由三层组成，由上层至下层(即沿着远离坩埚的方向)依次铺设有具有颗粒的平均粒径范围在8mm～30mm、小于等于2mm以及小于等于0.5mm的电阻颗粒层。
在一些实施方式中，示例性地，如图3所示，在将坩埚紧密堆放至艾奇逊石墨化炉主体1200中之前，可以先在艾奇逊石墨化炉主体1200底部铺设一层炭黑保护层1640，炭黑保护层1640的厚度为700mm，炭黑保护层1640的电阻值≥1000μΩ；在炭黑保护层上再覆盖一层第一下电阻颗粒层1622，第一下电阻颗粒层1622包括颗粒尺寸(平均粒径)小于等于2mm的煅后焦，且第一电阻发热颗粒料层(第一下电阻颗粒层1622)的电阻值为450μΩ～600μΩ。最后在第一下电阻颗粒层1622上再铺设一层第二下电阻颗粒层1624，第二下电阻颗粒层1624包括颗粒尺寸(平均粒径)为8mm～30mm的煅后焦，且第二下电阻颗粒层1624的电阻值为450μΩ～600μΩ。
据信，不受理论的约束，坩埚底部的电阻颗粒层和炭黑层可以实现良好的加热和控温作用，有效保持炉内的均匀加热和稳定放热。
(B)上区段：位于坩埚上方的艾奇逊石墨化炉炉腔内的铺设组成
参照附图2，在一些实施方式中，位于坩埚1420上方的艾奇逊石墨化炉主体1200的炉腔1240内铺设有上电阻颗粒层1820。在一些实施方式中，上电阻颗粒层1820可以包括至少四层，例如四层或更多层，五层或更多层，六层或更多层。在一些实施方式中，上电阻颗粒层1820的颗粒平均粒径由下层至上层(即沿着远离坩埚1420的方向)逐层递减。本公开上电阻颗粒层的粒径排布，是为了有效发挥靠近坩埚处颗粒层的加热作用，并且有效抑制因颗粒膨胀而造成坩埚破裂，以及有效发挥远离坩埚处颗粒层的加热和保温、隔绝空气作用。在一些实施方式中，坩埚1420上方的各个电阻颗粒层的厚度各自独立地为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。参照附图3，在一些实施方式中，上电阻颗粒层1820包括：第一上电阻颗粒层1822，设置在坩埚1420顶部上方；第二上电阻颗粒层1824，设置在第一上电阻颗粒层1822上方；第三上电阻颗粒层1826，设置在第二上电阻颗粒层1824上方；第四上电阻颗粒层1828，设置在第三上电阻颗粒层1826上方。
在一些实施方式中，第一上电阻颗粒层1822具有颗粒的平均粒径大于第二上电阻颗粒层具有颗粒的平均粒径。在一些实施方式中，第二上电阻颗粒层1824具有颗粒的平均粒径大于第三上电阻颗粒层1826具有颗粒的平均粒径。在一些实施方式中，第三上电阻颗粒层1826具有颗粒的平均粒径大于第四上电阻颗粒层1828具有颗粒的平均粒径。在一些实施方式中，电阻颗粒的平均粒径大小为：第一上电阻颗粒层1822>第二上电阻颗粒层1824>第三上电阻颗粒层1826>第四上电阻颗粒层1828。
在一些实施方式中，第一上电阻颗粒层1822具有颗粒的平均粒径范围在8mm～30mm，例如10mm～25mm，12mm～20mm，或15mm～18mm。在一些实施方式中，第二上电阻颗粒层1824具有颗粒的平均粒径范围在5mm～10mm，例如6mm～9mm，7mm～8mm。在一些实施方式中，第三上电阻颗粒层1826具有颗粒的平均粒径范围在2mm～4mm，例如2.5mm～3.5mm，2.8mm～3mm。在一些实施方式中，第四上电阻颗粒层1828具有颗粒的平均粒径范围大于0且小于等于2mm，例如0.1mm～1.8mm，0.5mm～1.5mm，或1mm～1.3mm。
在一些实施方式中，第一上电阻颗粒层1822、第二上电阻颗粒层1824、第三上电阻颗粒层1826、第四上电阻颗粒层1828的厚度各自独立地为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。在一些实施方式中，坩埚1420上方的电阻颗粒层的总厚度为20cm～100cm，或30cm～80cm，或35cm～60cm，或30cm～50cm。
本公开通过的上电阻颗粒层在上述不同粒径范围的分布组合，同样不仅实现了超高的是石墨化温度、长时间稳定的核心石墨化温度，而且同样并未因坩埚承载膜材料之间因存在空心间隙受到电阻颗粒膨胀挤压产生开裂。本公开提供的上电阻颗粒层的组合，在石墨化过程中，膨胀得到有效抑制，故并未引发上述因填充不实遭受电阻颗粒膨胀挤压产生开裂。。
同时本公开的上电阻颗粒层的特殊排布，不仅发挥邻近坩埚位置(如第一上电阻颗粒层、第二上电阻颗粒层)的加热作用并且有效抑制电阻颗粒的膨胀，而且更有效发挥远离坩埚的电阻颗粒层(如第三上电阻颗粒层、第四上电阻颗粒层)的加热和保温、隔绝空气作用，综上，电阻颗粒层在全程的石墨化过程中膨胀得到有效抑制。
同时本公开在靠近坩埚处的颗粒层(如第一上电阻颗粒层)平均粒径的范围了避免了粒径过小，导致的高温石墨化膨胀，颗粒容易挤压坩埚导致破裂，还避免了平均粒径过大，而造成的电流流经颗粒发热不均匀，且容易进入空气，达不到保温效果，和超高石墨化温度3000℃以上
本公开的上电阻颗粒层同样获得了稳定高温，保温，隔绝空气的特性，并且防止了因颗粒膨胀而引发的上述问题，同时配合上文下电阻颗粒层，进一步提高了炉内的超高温石墨化、保温和隔绝空气的特性。
在一些实施方式中，上电阻颗粒层还包括第五上电阻颗粒层，其设置在第四上电阻颗粒层上方。在一些实施方式中，第五上电阻颗粒层的平均粒径小于第四上电阻颗粒层。在一些实施方式中，第五上电阻颗粒层的平均粒径范围大于0且小于等于0.5mm，例如0.1mm、0.2mm、0.3mm、0.4mm、0.5mm。在一些实施方式中，第五上电阻颗粒层的厚度可以为5cm～25cm，或7cm～20cm，或8cm～15cm，或9cm～12cm。
上述上电阻颗粒层的增加是可以根据保温时间需求和降温需求选择性增加，可以进一步提高保温、隔绝空气的作用，可以实现3000℃～3200℃的石墨化温度范围。
在一些实施方式中，上电阻颗粒层1820包括四层或由四层组成，由下层至上层(即沿着远离坩埚1420的方向)依次铺设有具有颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm以及小于等于2mm的电阻颗粒层。在此实施方式中，可以实现的降温速率为5℃/h～15℃/h，降温时间为20天至30天。
在一些实施方式中，上电阻颗粒层1820包括五层或由五层组成，由下层至上层(即沿着远离坩埚1420的方向)依次铺设有具有颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm小于等于2mm以及小于等于0.5mm的电阻颗粒层。
在一些实施方式中，在将坩埚紧密堆放至艾奇逊石墨化炉中后，在坩埚外壁及坩埚之间铺设填埋8mm～30mm的煅后焦，在坩埚上层先覆盖一层8mm～30mm的颗粒状煅后焦，再覆盖一层5mm～10mm的颗粒状煅后焦；再覆盖一层2mm～4mm颗粒状煅后焦，最后覆盖一层粒径小于等于2mm的颗粒状煅后焦。需要说明的是，不同粒径的煅后焦在石墨化炉内通电产生的焦耳热不同，通过铺设不同粒径的煅后焦，有利于电阻发热颗粒(电阻颗粒)与还原氧化石墨烯膜共同构成炉阻，使电流流经炉内电阻发热颗粒(电阻颗粒)和还原氧化石墨烯膜后产生共热，使还原氧化石墨烯膜获得石墨化所需热量，同时，最上层的电阻发热颗粒(电阻颗粒)由于粒径小，填埋密实，起到保温效果更有利于保护炉内温度，延长石墨化保温时间，进而提高产品的石墨化率。选择使用煅后熟焦主要是电阻值更稳定，且熟焦含碳量超过99％，因此没有任何挥发物。
在一些实施方式中，利用上文所述实施方式中，坩埚底部的炭黑层和电阻颗粒层的共三层排布起到良好的屏蔽空气以及保温隔热作用；上文所述实施方式中坩埚顶部的电阻颗粒四层排布起到良好的隔绝空气和保温作用，可以实现3000℃～3200℃的石墨化温度范围。
据信，不受理论的约束，坩埚顶部的电阻颗粒层可以实现良好的加热和后期自然缓慢降温的作用。可以理解地，在石墨化过程中，氧化石墨烯膜产生的小分子挥发物，例如二氧化碳、一氧化碳、含氮化合物等，小分子挥发物会被粉状多孔电阻发热颗粒(电阻颗粒)吸收，不会造成任何废弃排放，电阻发热颗粒(电阻颗粒)价格低廉，且经过煅烧处理后可以重复使用。
(C)坩埚区段
在一些实施方式中，填充在坩埚1420周围的坩埚区段电阻颗粒1440的平均粒径为8mm～30mm。
参照附图4，在一些实施方式中，石墨化炉设备1000还包括电极区段1900。
在一些实施方式中，电极区段1900设置在电极1260和坩埚区段1400之间，与坩埚区段1400对应的位置。
在一些实施方式中，电极区段1900中填充有电极区段电阻颗粒1920。
在一些实施方式中，电极区段电阻颗粒1920的平均粒径为≤2mm。
(D)石墨化参数
作为本公开可选的实施方式，所述石墨化温度范围为3000℃～3200℃；所述高温热处理中的热处理周期为10天～30天。可以理解地，由于石墨化温度高且保温时间长，可以使产品在较长的石墨化周期中实现自身结构缺陷的修复，同时可以使石墨烯膜的内部结构重结晶形成大面积晶畴，使产品的电学、热学、力学性质达到最优。
在一些实施方式中，石墨化温度可以是例如3000℃～3100℃、3100℃～3200℃、3020℃～3180℃，诸如3000℃、3050℃、3100℃、3150℃、3200℃等等，热处理周期可以是例如10天～25天、12天～30天、15天～30天或20天～30天，诸如10天、15天、18天、20天、25天、28天或30天等等，当然也可以是上述范围内的其他值，在此不做限定。
作为本公开可选的实施方式，采用分段式升温至所述石墨化温度。
在本实施例中，艾奇逊石墨化炉包括炉体，炉体由炉基底、炉头墙体、炉尾墙体以及炉墙板围成的正四面体结构，所述炉头墙体和炉尾墙体内设置导电电极，所述炉基底上依次铺设石英砂和炭黑保温层，所述保温层上为炉芯，将所述石墨坩埚置于炉芯沿炉方向设置，坩埚间隙填充煅后焦，上层交替铺设填埋电阻发热颗粒(电阻颗粒)层，所述炉芯顶部和侧边设置成型版，所述成型版内铺设填埋电阻发热颗粒(电阻颗粒)。
在一些实施方式中，步骤S20，包括
第一阶段，将所述艾奇逊石墨化炉温度升温至1000℃～1400℃，保温5h～10h后；
第二阶段，将所述艾奇逊石墨化炉内温度继续升温至2000℃～2100℃，保温5h～10h；
第三阶段，将所述艾奇逊石墨化炉内温度继续升温至2800℃～2900℃，保温2h～5h，再继续升温至3000℃～3200℃，保温5h～10h；
停止送电，将艾奇逊石墨化炉自然降温，得到结构缺陷修复和重结晶的蓬松石墨烯膜。
在上述步骤S20中，第一阶段的升温主要使产品中的一些化合物裂解挥发完成，如果该阶段不保留，容易使一些化合物来不及挥发被直接石墨化陷入产品结构内导致缺陷，例如气孔。
第二节段升温保持，主要是石墨化开始阶段，石墨化温度开始于2000℃，这个过程是碳素结成晶核过程，如果不保留则容易产生多晶态，结晶产生杂质。
第三阶段升温是真正的石墨化结晶生长阶段，这个阶段温度最高(温度达到3000℃～3200℃)，结晶通过均匀的晶核开始外延生长，生成大面积单晶，使产品各方面物理性能得到提高。还原氧化石墨烯膜的石墨化的起始温度为约2100℃，在2100℃下，其C-C键发生断裂，但是如苯环C-C键断裂还需更高温度，随着温度的增高C-C键断裂更彻底，C-C键断裂后重组结晶得到完美晶体，本公开的还原氧化石墨烯膜在上述石墨化结晶生长阶段，通过高温处理，可以使得C-C键断裂更彻底，获得生成大面积单晶的石墨烯膜，从而进一步提高了石墨烯膜的物理性能诸如热传导和导电性能。
在第三阶段中，当艾奇逊石墨化炉内的温度达到2900℃，先进行保温，再升至石墨化温度3000℃～3200℃，能使炉内温 度均匀，使坩埚内石墨烯膜受热均匀，进而提高结晶的取向性，使得产品性能提高。
在一些实施方式中，自然降温的降温速率为5℃/h～15℃/h，降温时间为9天至30天。在一些实施方式中，降温速率可以是例如5℃/h～8℃/h、6℃/h～15℃/h、5℃/h～10℃/h或8℃/h～15℃/h，诸如5℃/h、7℃/h、8℃/h、10℃/h、12℃/h、13℃/h、14℃/h或15℃/h等，在此不做限定。降温时间为例如9天至20天、10天至30天、15天至30天或12天至28天，诸如9天、10天、11天、12天、15天、17天、19天、20天、25天或30天等，在此不做限定。需要说明的是，在降温过程中，降温前期的降温速率较快，降温后期的降温速率较慢，即炉内温度越接近室温降温越慢。
可以理解地，在自然降温过程中，石墨烯在慢速降温过程中实现缺陷修复和结构重结晶得到石墨烯膜片，可以促使小片层石墨烯片结晶重组成大片层石墨烯片，提高石墨烯膜的导热性能以及结构强度。结晶过程通常发生在降温过程中，降温速率越慢，结晶程度越好，产品性能越好，快速降温会导致结晶取向变差，形成微晶，产品性能下降。
步骤S30，将所述蓬松石墨烯膜进行压实致密化处理，得到石墨烯膜。
作为本公开可选的实施方式，所述蓬松石墨烯膜的压实压强为2MPa～100MPa，例如可以为5MPa～100MPa、10MPa～100MPa、50MPa～100MPa或2MPa～80MPa，诸如可以是2MPa、5MPa、10MPa、20MPa、30MPa、35MPa、40MPa、50MPa、60MPa、70MPa、80MPa、90MPa或100MPa等，当然也可以是上述范围内的其他值，在此不做限定。通过压实致密化处理，可以使得石墨烯膜结构强度更高，密度更高。
II.石墨烯膜
本公开一实施方式提供一种石墨烯膜，所述石墨烯膜通过上述第一方面所述的制备方法制得。
作为本公开可选的实施方式，石墨烯膜的厚度为10μm～300μm，具体可以是10μm、50μm、100μm、150μm、200μm、250μm、280μm或300μm等等，在此不做限定。石墨烯膜的厚度可以通过厚度测试仪测得。
作为本公开可选的实施方式，所述石墨烯膜的密度为1.8g/cm 3～2.3g/cm 3，具体可以是1.8g/cm 3、1.9g/cm 3、2.0g/cm 3、2.1g/cm 3、2.2g/cm 3或2.3g/cm 3等，当然也可以是上述范围内的其他值，在此不做限定。可以理解地，石墨烯膜密度的提高，有利于产品轻薄化应用。石墨烯膜的密度可以根据预设单位体积v的石墨烯膜的质量m，密度ρ＝m/v，测得石墨烯膜的密度。
作为本公开可选的实施方式，所述石墨烯膜的导热系数为1300W/mK～1600W/mK，具体可以是1300W/mK、1350W/mK、1400W/mK、1450W/mK、1500W/mK、1550W/mK或1600W/mK等，当然也可以是上述范围内的其他值，在此不做限定。石墨烯膜的导热系数越高，石墨烯膜的导热性能越强。在一些实施方式中，石墨烯膜的导热系数可以通过ASTM-E1461标准测得。
作为本公开可选的实施方式，所述石墨烯膜的拉伸强度为50MPa～65MPa，具体可以是50MPa、52MPa、55MPa、58MPa、60MPa、62MPa或65MPa等，当然也可以是上述范围内的其他值，在此不做限定。石墨烯膜的拉伸强度在上述范围内，有利于提高石墨烯膜的机械性能，可以提高石墨烯膜的抗撕裂性能。在一些实施方式中，石墨烯膜的拉伸强度可以通过GB/T 1040.1-2018标准测得。
III.电子设备
本公开一实施方式提供一种电子设备，所述电子设备包含如上述第一方面所述的石墨烯膜的制备方法制得的石墨烯膜或上述第二方面的石墨烯膜。
本公开提供的一种石墨烯膜及其制备方法，能够降低生产成本，缩短制备工艺，提高石墨烯膜的性能。
本公开提供的石墨烯膜的制备方法，包括：将还原氧化石墨烯膜放入艾奇逊石墨化炉的坩埚内，坩埚外壁铺设填埋不同粒径的电阻发热料。由本公开提供的基于艾奇逊石墨炉的石墨化炉的内部电阻颗粒与还原氧化石墨烯膜共同构成炉阻，通过施加大电流，电流流经炉内电阻颗粒以及还原氧化石墨烯膜后共同产生巨大热能。还原氧化石墨烯膜由于自身电阻产生热量，同时坩埚外壁铺设填埋的不同颗粒电阻颗粒也由于自身电阻产生热能，与坩埚内部的还原氧化石墨烯膜形成共热，使坩埚内外形成共热体，从而实现超高的石墨化温度。同时得益于坩埚周边填埋不同粒径的电阻颗粒，坩埚内的核心石墨化温度保持稳定，进而使石墨烯膜产品的结构缺陷在超高温石墨化温度下以及超长的石墨化保温过程中得以完美修复。在此基础上，通过本公开对于电阻颗粒的特定排布，不仅持续且稳定地提供所需的高温，兼具发热、保温和隔绝空气的作用，且有效保持了内部炉阻的统一、均匀和稳定，进一步提高了石墨烯膜的热传导和导电性能；选择的电阻颗粒过小，则经高温石墨化膨胀，颗粒容易挤压坩埚导致破裂，选择的电阻颗粒过大，则电流流经颗粒发热不均匀，且容易进入空气，同时，保温效果达不到，焦耳热很难达到3000℃以上，而本公开通过对粒径不同的电阻颗粒的特定排布，获得了稳定高温，保温，隔绝空气的特性。在降温过程中通过缓慢交替移除电阻颗粒，进一步使石墨烯膜在漫长的降温过程中实现结构的重新结晶生成大面积晶畴，使产品的电学、热学、力学性质达到前所未有的高度。相较于使用结构复杂且使用寿命短的电磁感应加热式石墨化炉进行石墨化，采用由本公开提供的石墨化炉进行石墨化的方法更简单、易于实现、批量生产可靠且故障率极低。另外，该石墨化炉中的电阻颗粒和坩埚内的部分还原氧化石墨烯膜由于自身电阻大再流经电流后产生巨大的共热效果使产品达到超高石墨化温度，其加热原理有别于其他石墨化加热方式。由于由本公开提供的石墨化炉的长期使用可靠性强、故障率低、石墨化程度高、工艺简单等，不仅降低了石墨烯膜的整体制造成本，同时使材料性能得到了大幅度提升，产品的核心竞争力得到加强。
下面分多个实施例对本公开实施例进行进一步的说明。其中，本公开实施例不限定于以下的具体实施例。在保护范围内，可以适当的进行变更实施。
实施例
I.石墨烯膜制备过程中的参数测试方法
针对以下实施例和对比例中所涉及的参数测试方法如下：
(1)平均粒径：通过粒度测试仪，型号为马尔文激光粒度仪3000，来检测分析颗粒材料的平均粒径；
(2)压实压强：利用辊压机将石墨化后的蓬松石墨烯膜在以下实施例和对比例给定的压强下(通过调配设定辊压机的压力)，进行压实致密化处理(辊压机直接显示压实压强数值)。
II.石墨烯膜的性能测试方法
针对以下实施例和对比例制备的石墨烯膜进行性能测试，测试方法如下：
(1)石墨烯膜厚度测定：
采用日本三丰Mitutoyo数显厚度表547-315薄片测砧测厚仪，对石墨烯膜的单张膜取4个点进行厚度测定，并取平均值；
(2)密度：
将石墨烯膜切割成长方体或立方体，对石墨烯膜进行称重，测定其质量；并对该膜的长、宽、高进行测量计算其体积，进而计算膜的密度，其中，密度(g/cm 3)＝重量÷体积；
(3)导热系数:
计算公式为：导热系数(W/mK)＝密度×0.85×热扩散系数，
其中，0.85为石墨烯膜的比热容，单位J/g·K；密度则为上文(2)中所测定的石墨烯膜的密度；热扩散系数的测定则参照ASTM E1461-2013(闪光法测定热扩散率的标准试验方法)，采用激光导热仪LA467进行测定；
(4)拉伸强度：
参照方法GB/T1040.1-2018，采用日本岛津AGS-X进行测定。
实施例1
制备方法：一种石墨烯膜的制备方法，包括以下步骤：
(1)采用机械搅拌和高压均质的方式将浓度为62mg/mL的氧化石墨烯通过物理破碎和高压均质后获得均相氧化石墨烯浆料；
(2)采用涂布的方式，将氧化石墨烯浆料进行涂布作业，烘干后获得氧化石墨烯膜；
(3)将氧化石墨烯膜置入烤箱中以10℃/h的速率升温至500℃并保温20小时，以去除氧化石墨烯膜表面和内部的水分和含氧化学官能团，得到还原氧化石墨烯膜，此时测得，还原氧化石墨烯膜的挥发组分为8wt％；
(4)将烘烤后的还原氧化石墨烯膜与石墨纸层叠后放入石墨坩埚中，再将石墨坩埚堆叠置入艾奇逊石墨化炉中，采用分段式送电升温方式进行石墨化处理。其中，所述第一阶段，根据变压器的额定功率和额定电压，采用最大功率输出促使炉内电流密度快速达到升温条件使炉体自由升温至1200℃并保温10小时；第二阶段在调整输出功率下使产品在满载大电流的情况下拉升至2100℃，并保温10小时，第三阶段为通过调整输出功率下使产品在大电流情况下迅速拉升至2900℃并保温3小时，并在小电流稳定输出功率下将温度稳步提升至3200℃，维持小电流输出功率保温5小时后，产品在持续21天的自然降温过程中实现结构缺陷的修复和重结晶得到蓬松石墨烯膜。
(5)将石墨化后的蓬松石墨烯膜在90MPa的压强下进行压实致密化处理，得到石墨烯膜。
石墨化炉的结构：该石墨化方法采用石墨化炉设备进行，该设备结构参照图4，石墨化炉设备1000，包括：
艾奇逊石墨化炉主体1200，包括炉壁1220、由炉壁1220包围构成的炉腔1240和电极1260；
坩埚区段1400，设置在炉腔1240内与电极1260对应的位置，包括多个坩埚1420和填充在坩埚1420周围的坩埚区段电阻颗粒1440，坩埚1420内铺设有还原氧化石墨烯膜1460；下区段1600，设置坩埚区段1400下方炉腔1240内，包括下电阻颗粒层1620；以及上区段1800，设置坩埚区段1400上方炉腔1240内，包括上电阻颗粒层1820；
下区段1600中，下电阻发热颗粒层包括第一下电阻颗粒层1622以及铺设在第一下电阻颗粒层1622上层的第二下电阻颗粒层1624；第一下电阻颗粒层1622包括颗粒平均粒径为1mm的煅后焦，且第一下电阻颗粒料层1622的电阻值为450μΩ～600μΩ；第二下电阻颗粒层1624包括颗粒平均粒径为18mm的煅后焦，且第二下电阻颗粒层1624的电阻值为450μΩ～600μΩ；第一下电阻颗粒料层1622、第二下电阻颗粒层1624的厚度分别为18cm和15cm；
下区段1600还包括设置在下电阻发热颗粒层下方的保护层1640，该保护层1640为炭黑保护层，炭黑保护层的厚度为700mm，炭黑保护层的电阻值≥1000μΩ；
在将坩埚1420紧密堆放至艾奇逊石墨化炉主体1200中后，在坩埚区段1400中，在坩埚1420外壁之间填充有坩埚区段电阻颗粒1440，颗粒的平均粒径为18mm；
在上区段1800中，上电阻发热颗粒层由下层至上层(即沿着远离坩埚1420的方向)依次铺设有第一上电阻颗粒层1822(平均粒径18mm)、第二上电阻颗粒层1824(平均粒径7mm)、第三上电阻颗粒层1826(平均粒径3mm)和第四上电阻颗粒层1828(平均粒径为1mm)；第一上电阻颗粒层1822、第二上电阻颗粒层1824、第三上电阻颗粒层1826、第四上电阻颗粒层1828的厚度分别为10cm、12cm、13cm、14cm；
石墨化炉设备1000还包括电极区段1900，电极区段1900设置在电极1260和坩埚区段1400之间，与坩埚区段1400对应的位置，电极区段1900中填充有电极区段电阻颗粒1920，电极区段电阻颗粒1920的平均粒径为1mm；
以上所述颗粒层均为颗粒状煅后焦。
本实施方式制备的石墨烯膜厚度为100μm，密度为2.04g/cm 3，导热系数为1556.9W/mK，拉伸强度64MPa。
实施例2
制备方法：实施例2的制备方法与实施例1相同。
石墨化炉结构：实施例2的石墨化炉设备1000与实施例1相近，不同之处在于：
第一下电阻颗粒层1622的颗粒平均粒径为0.5mm；第二下电阻颗粒层1624的颗粒平均粒径为8mm的煅后焦；第一下电阻颗粒料层1622、第二下电阻颗粒层1624的厚度分别为10cm和8cm；
炭黑保护层的厚度为600mm，炭黑保护层的电阻值≥1000μΩ；
坩埚1420外壁之间填充的坩埚区段电阻颗粒1440的平均粒径为8mm；
在上区段1800中，第一上电阻颗粒层1822(平均粒径8mm)、第二上电阻颗粒层1824(平均粒径5mm)、第三上电阻颗粒层1826(平均粒径2mm)和第四上电阻颗粒层1828(平均粒径为0.5mm)；第一上电阻颗粒层1822、第二上电阻颗粒层1824、第三上电阻颗粒层1826、第四上电阻颗粒层1828的厚度分别为5cm、8cm、12cm、15cm；
电极区段1900中填充的电极区段电阻颗粒1920的平均粒径为0.5mm。
实施例3
制备方法：实施例3的制备方法与实施例1相同。
石墨化炉的结构：实施例3的石墨化炉设备1000与实施例1相近，不同之处在于：
第一下电阻颗粒层1622包括颗粒平均粒径为2mm的煅后焦；第二下电阻颗粒层1624包括颗粒平均粒径为30mm的煅后焦；第一下电阻颗粒料层1622、第二下电阻颗粒层1624的厚度分别为25cm和20cm；
保护层1640的厚度为800mm；
坩埚1420外壁之间填充的坩埚区段电阻颗粒1440的平均粒径为30mm；
在上区段1800中，第一上电阻颗粒层1822(平均粒径30mm)、第二上电阻颗粒层1824(平均粒径10mm)、第三上电阻颗粒层1826(平均粒径4mm)和第四上电阻颗粒层1828(平均粒径为2mm)；第一上电阻颗粒层1822、第二上电阻颗粒层1824、第三上电阻颗粒层1826、第四上电阻颗粒层1828的厚度分别为15cm、18cm、20cm、25cm；
电极区段1900中填充的电极区段电阻颗粒1920的平均粒径为2mm。
实施例4
实施例4的制备方法与实施例1相同。
实施例4的石墨化炉设备1000与实施例1相近，不同之处在于：
参照附图5，下区段1600中，下电阻发热颗粒层还包括第三下电阻颗粒层1626，第三下电阻颗粒层1626铺设在在第一下电阻颗粒层1622下层，具有的平均粒径为0.1mm，厚度为18cm；
在上区段1800中，还包括第五上电阻颗粒层1829，第五上电阻颗粒层1829设置在第四上电阻颗粒层1828的上方，具有的平均粒径为0.1mm，厚度为15cm。
实施例5
(1)采用超声和机械剪切剥离的方式将浓度为8mg/mL的氧化石墨通过超声破碎和剪切剥离后获得均相氧化石墨烯浆料；
(2)采用喷涂的方式，将氧化石墨浆料在底材上进行喷涂作业，烘干后获得氧化石墨烯膜；
(3)将氧化石墨烯膜置入烤箱中以5℃/h的速率升温至430℃的并保温10小时，以去除氧化石墨烯膜表面和内部的水分和含氧化学官能团，得到还原氧化石墨烯膜，此时测得，还原氧化石墨烯膜的挥发组分为5wt％；
(4)将烘烤后的还原氧化石墨烯膜与石墨纸层叠后放入石墨坩埚中，再将石墨坩埚堆叠置入艾奇逊石墨化炉中，采用分段式送电升温方式进行石墨化处理。其中，所述第一阶段，根据变压器的额定功率和额定电压，采用最大功率输出促使炉内电流密度快速达到升温条件使炉体自由升温至1200℃并保温10小时；第二阶段在调整输出功率下使产品在满载大电流的情况下拉升至2100℃，并保温10小时，第三阶段为通过调整输出功率下使产品在大电流情况下迅速拉升至2900℃并保温3小时，第四阶段为在小电流稳定输出功率下将温度稳步提升至3200℃，维持小电流输出功率保温5小时后。产品在持续21天的自然降温过程中实现结构缺陷的修复和重结晶得到蓬松石墨烯膜。
(5)将石墨化后的蓬松石墨烯膜在65MPa的压强下进行压实致密化处理，得到石墨烯膜。
其中，艾奇逊石墨化炉中的炭黑保护层和电阻颗粒层排布同实施例1。
本实施方式制备的石墨烯膜厚度为65μm，密度为2.05g/cm 3，导热系数为1478.5W/mK，拉伸强度55MPa。
实施例6
一种石墨烯膜的制备方法，包括以下步骤：
(1)采用机械搅拌和高压均质的方式将浓度为12gm/mL的氧化石墨烯通过物理破碎和高压均质后获得均相氧化石墨烯浆料；
(2)采用离心旋涂的方式，将氧化石墨烯浆料在特制基底上通过离心旋转方式均匀涂敷一层浆料，烘干后获得氧化石墨烯膜；
(3)将氧化石墨烯膜置入烤箱中以2℃/h的速率升温至500℃并保温30小时，以去除氧化石墨烯膜表面和内部的水分 和含氧化学官能团，得到还原氧化石墨烯膜，此时测得，还原氧化石墨烯膜的挥发组分为10wt％；
(4)将烘烤后的还原氧化石墨烯膜与石墨纸层叠后放入石墨坩埚中，再将石墨坩埚堆叠置入艾奇逊石墨化炉中，采用分段式送电升温方式进行石墨化处理。其中，所述第一阶段，根据变压器的额定功率和额定电压，采用最大功率输出促使炉内电流密度快速达到升温条件使炉体自由升温至1200℃并保温10小时；第二阶段在调整输出功率下使产品在满载大电流的情况下拉升至2100℃，并保温10小时，第三阶段为通过调整输出功率下使产品在大电流情况下迅速拉升至2900℃并保温3小时，并在小电流稳定输出功率下将温度稳步提升至3200℃，维持小电流输出功率保温5小时后，产品在持续21天的自然降温过程中实现结构缺陷的修复和重结晶得到蓬松石墨烯膜。
(5)将石墨化后的蓬松石墨烯膜在90MPa的压强下进行压实致密化处理，得到石墨烯膜。
其中，艾奇逊石墨化炉中的炭黑保护层和电阻颗粒层排布同实施例1。
本实施方式制备的石墨烯膜厚度为198μm，密度为2.04g/cm 3，导热系数为1309.4W/mK，拉伸强度55MPa。
实施例7
一种石墨烯膜的制备方法，包括以下步骤：
(1)采用机械搅拌和机械剪切的方式将浓度为2gm/mL的氧化石墨烯通过物理剪切破碎后获得均相氧化石墨烯浆料；
(2)采用提拉浸涂的方式，将特质基板浸入氧化石墨烯浆料中，通过一定速率提拉使氧化石墨烯浆料均匀附着在基板上，烘干脱模后获得氧化石墨烯膜；
(3)将氧化石墨烯膜置入烤箱中以5℃/h的速率升温至450℃并保温30小时，以去除氧化石墨烯膜表面和内部的水分和含氧化学官能团，此时测得，还原氧化石墨烯的挥发组分为6wt％；
(4)将烘烤后的还原氧化石墨烯膜与石墨纸层叠后放入石墨坩埚中，再将石墨坩埚堆叠置入艾奇逊石墨化炉中，采用分段式送电升温方式进行石墨化处理。其中，所述第一阶段，根据变压器的额定功率和额定电压，采用最大功率输出促使炉内电流密度快速达到升温条件使炉体自由升温至1200℃并保温8小时；第二阶段在调整输出功率下使产品在满载大电流的情况下拉升至2100℃，并保温9小时，第三阶段为通过调整输出功率下使产品在大电流情况下迅速拉升至2900℃并保温5小时，并在小电流稳定输出功率下将温度稳步提升至3200℃，维持小电流输出功率保温8小时后，产品在持续21天的自然降温过程中实现结构缺陷的修复和重结晶得到蓬松石墨烯膜。降温过程是通过负压吸尘器均匀吸除铺设的电阻颗粒，使得电阻颗粒移除，一层层暴露在空气中，实现自然降温过程，通过人为干涉层层移除最上层的电阻颗粒，实现降温时间可调。
(5)将石墨化后的蓬松石墨烯膜在50MPa的压强下进行压实致密化处理，得到石墨烯膜。
其中，艾奇逊石墨化炉中的炭黑保护层和电阻颗粒层排布同实施例1。
本实施4方式制备的石墨烯膜厚度为120μm，密度为1.95g/cm 3，导热系数为1302.8W/mK，拉伸强度53MPa。
对比例1
(1)采用机械搅拌和高压均质的方式将浓度为62gm/mL的氧化石墨烯通过物理破碎和高压均质后获得均相氧化石墨烯浆料；
(2)采用涂布的方式，将氧化石墨烯浆料进行涂布作业，烘干后获得氧化石墨烯膜；
(3)将氧化石墨烯膜置入烤箱中以10℃/h的速率升温至500℃并保温20小时，以去除氧化石墨烯膜表面和内部的水分和含氧化学官能团，得到还原氧化石墨烯膜，此时测得，还原氧化石墨烯膜的挥发组分为8wt％；
(4)将烘烤后的还原氧化石墨烯膜与石墨纸层叠后放入电磁感应式石墨化炉中进行石墨化处理。其中，还原氧化石墨烯膜在电磁感应石墨化炉中以2800℃处理30min获得蓬松石墨烯膜。
(5)将石墨化后的蓬松石墨烯膜在90MPa的压强下进行压实致密化处理，得到石墨烯膜。
本对比例制得的石墨烯膜厚度为100μm，密度为2.03g/cm 3，导热系数为996.7W/mK，拉伸强度42MPa。
对比例2
对比例2的制备方法与实施例1的不同之处在于步骤(4)的热处理条件为：以2800℃处理30min获得蓬松石墨烯膜；
对比例2的石墨化炉设备与实施例1的不同之处在于：
下区段1600中，仅包含一层下电阻颗粒层，平均粒径为18mm，厚度为33cm；
且不设置保护层1640；
在上区段1800中，仅包含一层上电阻颗粒层，平均粒径为18mm，厚度为49cm；
电极区段1900中填充有电极区段电阻颗粒1920，电极区段电阻颗粒1920的平均粒径为18mm。
对比例3
对比例3的制备方法与实施例1的不同之处在于步骤(4)的热处理条件为：以2800℃处理30min获得蓬松石墨烯膜；
对比例3的石墨化炉设备与对比例1的不同之处在于：
下区段1600还包括设置在下电阻发热颗粒层下方的保护层1640，该保护层1640为炭黑保护层，炭黑保护层的厚度为700mm，炭黑保护层的电阻值≥1000μΩ。
对比例4
对比例4的制备方法与实施例1的不同之处在于步骤(4)的热处理条件为：以2800℃处理30min获得蓬松石墨烯膜；
对比例4的石墨化炉设备与实施例1的不同之处在于：
下区段1600中，仅包含一层下电阻颗粒层，平均粒径为2mm，厚度为33cm；
且不设置保护层1640；
在上区段1800中，仅包含一层上电阻颗粒层，平均粒径为2mm，厚度为49cm；
电极区段1900中填充有电极区段电阻颗粒1920，电极区段电阻颗粒1920的平均粒径为2mm。
以上实施例和对比例制备的石墨烯的性能参数总结在以下表1中。
表1 为本公开实施例1-7、对比例1-4的性能参数表
  厚度um 密度g/cm 3 热导率W/mK 拉伸强度MPa
实施例1 100 2.04 1556.9 64
实施例2 105 2.10 1520.5 60
实施例3 98 2.18 1604.8 58
实施例4 96 2.16 1568.5 62
实施例5 65 2.05 1478.5 55
实施例6 198 2.04 1309.4 55
实施例7 120 1.95 1302.8 53
对比例1 100 2.03 996.7 42
对比例2 96 1.98 1120.5 29
对比例3 98 2.09 950.6 37
对比例4 103 2.13 1089.8 40
请参考表1、以图6a至图6e为例，并以实施例1、5、6、7为例的测试数据可知，参见图6a和6e，实施例1制备的石墨烯膜表面光滑平整，几乎看不到任何空隙或者褶皱，而对比例1制备的石墨烯膜不仅存在褶皱，而且存在空隙，说明实施例1的石墨烯膜在内部结构重结晶形成了大面积晶畴，实现了结构缺陷修复，并得到重结晶的蓬松石墨烯膜。通过参照表1，可以看出，实施例1制备得到的石墨烯膜具有热导率显著高于对比例1，具有优异的热传导性能；同时实施例1的石墨烯膜的拉升强度明显高于对比例1，具有优异的力学性能。
同样，实施例2-7制备得到的石墨烯膜在结构和性能上均与实施例1相近。本实施例1采用艾奇逊石墨化炉对还原氧化石墨烯膜进行石墨化处理，其中艾奇逊石墨化炉内的电阻发热颗粒(电阻颗粒)与坩埚内的还原氧化石墨烯膜共同构成炉阻，通过施加电流，使电阻发热颗粒(电阻颗粒)和氧化石墨烯膜产生共热从而达到极高的石墨化温度，得益于坩埚周边填埋不同粒径的电阻发热颗粒(电阻颗粒)，坩埚内的核心石墨化温度保持稳定，可以实现在电阻颗粒降温的过程中的自然缓慢降温，在后续将电阻颗粒降温期间，通过缓慢交替移除电阻发热颗粒(电阻颗粒)，进一步使石墨烯膜在漫长的降温过程中实现结构的重新结晶生成大面积晶畴，使得石墨烯膜的热学、力学性质均有所提高。
对比例1采用电磁感应式加热方式的石墨化温度工作极限为2900℃，且极限工作温度保温时间短，还原氧化石墨烯膜的石墨化温度不能超过3000℃，导致制得的石墨烯膜的电学、热学、力学性质均有所下降。且电磁感应石墨化炉由于结构设计需要，在停止加热后必须采用冷却水使电磁感应线圈快速降温来避免核心部件严重老化，在加速降温过程中石墨烯膜结构难以实现完美修复，且结晶取向度差，限制了石墨烯膜的电学、热学、力学性能。需要说明的是，由于电磁感应石墨化炉的加热方式是通过高压电流产生磁场，磁场在导体中产生感应电流，从而使导体发热，在这个过程中，所述导体必须为高纯或等静压石墨坩埚，氧化石墨烯膜置于上述坩埚中，通过坩埚自身发热来带动达到石墨化温度。由于是通过电磁转换加热，电、磁、热之间的转换无法达到稳定切换，造成升温控制困难；此外，电磁转换效率会随着坩埚治具的体积变大使热效能急剧降低，从而很难达到较高的石墨化温度以及石墨化的保温时间，因此采用电磁感应式石墨化方式不仅限制了产能，增加了昂贵的维护成本，最重要的是石墨化温度无法达到预期效果，从而影响石墨烯膜的电学、热学、力学性能。
另外，针对于对比例2-4，当电阻颗粒选择单一粒径或者额外添加保温层时，其还原氧化石墨烯膜的石墨化温度无法达到3000℃，且极限工作温度保温时间短，难以实现长时间石墨化高温制备(诸如3200℃，5-8h)，从而导致制得的石墨烯膜的电学、热学、力学性质均有所下降。
同时对比例2-4也无法实现本公开分段高温的长时制备，因为该制备方法会引起加热区段坩埚的开裂、爆裂甚至是炉体的爆裂，引发安全隐患，故对比例2-4只能选择高温短时制备。同时由表1可以看出，对比例2-4制备得到的石墨烯的热导率和力学性能均远低于本公开制备的石墨烯膜。实施例1-7制备得到的石墨烯膜具有热导率显著高于对比例2-4，具有优异的热传导性能；实施例1-7的石墨烯膜的拉升强度页明显高于对比例2-4，具有优异的力学性能。
本公开虽然以优选的实施例公开如上，但并不是用来限定权利要求，任何本领域技术人员在不脱离本公开构思的前提下，都可以做出若干可能的变动和修改，因此本公开的保护范围应当以本公开权利要求所界定的范围为准。
工业实用性
本公开提供的石墨烯膜及其制备方法，本公开的制备方法，能够降低生产成本，简化制备工艺，大幅度提高石墨烯膜的热传导性能；同时本公开提供的石墨烯膜产品的结构缺陷在超高温石墨化温度下以及超长的石墨化保温过程中得以完美修复， 具有优异的热学、力学性能，具有广泛的应该价值和实用性能。

Claims (16)

  1. 一种石墨烯膜的制备方法，其特征在于，所述方法包括以下步骤：
    将还原氧化石墨烯膜放入艾奇逊石墨化炉中，进行不同阶段的高温热处理使得所述还原氧化石墨烯膜达到石墨化温度，自然降温得到蓬松石墨烯膜；
    将所述蓬松石墨烯膜进行压实致密化处理，得到石墨烯膜。
  2. 根据权利要求1所述的制备方法，其特征在于，将所述还原氧化石墨烯膜置于所述艾奇逊石墨化炉内的坩埚中，所述艾奇逊石墨化炉内的坩埚之间与坩埚表面均铺设填埋电阻颗粒，所述电阻颗粒发热升温至石墨化温度；所述电阻颗粒的平均粒径范围为0至30mm，且不包括0mm。
  3. 根据权利要求1所述的制备方法，其特征在于，将所述还原氧化石墨烯膜与石墨纸层叠后放入所述艾奇逊石墨化炉内的坩埚中，所述艾奇逊石墨化炉内的坩埚之间与坩埚表面均铺设填埋电阻发热颗粒，所述电阻发热颗粒发热升温至石墨化温度；所述电阻发热颗粒包括不同粒径的煅后焦，所述煅后焦的平均粒径范围为0至30mm，且不包括0mm。
  4. 根据权利要求2或3所述的制备方法，其特征在于，位于所述坩埚下方的艾奇逊石墨化炉的炉腔内由上层至下层依次铺设有电阻颗粒层和保护层；位于所述坩埚上方的艾奇逊石墨化炉的炉腔内铺设有电阻颗粒层。
  5. 根据权利要求4所述的制备方法，其特征在于，所述方法满足以下特征a至e中的至少一种：
    a.位于所述坩埚下方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括至少两层，且各层所述电阻颗粒层的颗粒平均粒径由上层至下层逐层递减；
    b.位于所述坩埚上方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括至少四层，且各层所述电阻颗粒层的颗粒平均粒径由下层至上层逐层递减；
    c.位于所述坩埚下方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括两层，包括由上层至下层依次铺设颗粒的平均粒径范围在8mm～30mm和小于等于2mm的电阻颗粒层；
    d.位于所述坩埚上方的艾奇逊石墨化炉的炉腔内的电阻颗粒层包括四层，包括由下层至上层依次铺设颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm以及小于等于2mm的电阻颗粒层；
    e.所述电阻颗粒包括煅后石油焦、生石油焦或炭黑中的至少一种。
  6. 根据权利要求1-5中任一项所述的制备方法，其特征在于，所述还原氧化石墨烯膜中的挥发组分低于10wt％。
  7. 根据权利要求1-6中任一项所述的制备方法，其特征在于，所述方法满足以下特征a至c中的至少一种：
    a.所述石墨化温度范围为3000℃～3200℃；
    b.所述高温热处理中的热处理周期为10天～30天；
    c.采用分段式升温至所述石墨化温度。
  8. 根据权利要求1-7中任一项所述的制备方法，其特征在于，所述高温热处理，包括：
    第一阶段，将所述艾奇逊石墨化炉温度升温至1000℃～1400℃，保温5h～10h后；
    第二阶段，将所述艾奇逊石墨化炉内温度继续升温至2000℃～2100℃，保温5h～10h；
    第三阶段，将所述艾奇逊石墨化炉内温度继续升温至2800℃～2900℃，保温2h～5h，再继续升温至3000℃～3200℃，保温5h～10h；
    停止送电，将艾奇逊石墨化炉自然降温，得到蓬松石墨烯膜。
  9. 根据权利要求1-8中任一项所述的制备方法，其特征在于，所述蓬松石墨烯膜的压实压强为2MPa～100MPa。
  10. 根据权利要求1-9中任一项所述的制备方法，其特征在于，在将还原氧化石墨烯膜放入艾奇逊石墨化炉中之前，所述方法还包括；
    将含氧化石墨烯或氧化石墨的浆料制备得到的氧化石墨烯膜进行烘烤，得到还原氧化石墨烯膜。
  11. 根据权利要求10所述的制备方法，其特征在于，所述方法满足以下特征a至f中的至少一种：
    a.所述含氧化石墨烯或者所述氧化石墨的浆料浓度为1mg/mL～80mg/mL；
    b.所述含氧化石墨烯或者所述氧化石墨的浆料通过以下的任意一种方式来混合获得：超声、机械剪切剥离、机械搅拌 及高压均质；
    c.所述氧化石墨烯膜的制备工艺包括抽滤工艺、浸涂工艺、旋涂工艺、喷涂工艺、蒸发工艺及涂布工艺中的任意一种方式；
    d.所述烘烤的温度为150℃～550℃；
    e.所述烘烤的升温速率为0.5℃/h～10℃/h；
    f.所述烘烤的保温时间为5h～50h。
  12. 一种石墨烯膜，其特征在于，所述石墨烯膜通过权利要求1至11任一项所述的制备方法制得，所述石墨烯膜满足以下特征a至d中的至少一种：
    a.所述石墨烯膜的厚度为10μm～300μm；
    b.所述石墨烯膜的密度为1.8g/cm 3～2.3g/cm 3；
    c.所述石墨烯膜的导热系数为1300W/mK～1600W/mK；
    d.所述石墨烯膜的拉伸强度为50MPa～65MPa。
  13. 一种电子设备，其特征在于，所述电子设备包含如权利要求1至11任一项所述的石墨烯膜的制备方法制得的石墨烯膜或权利要求12所述的石墨烯膜。
  14. 一种石墨化炉设备，包括：
    石墨化炉主体，包含炉壁、由炉壁包围构成的炉腔、和电极；
    坩埚区段，设置在炉腔内与电极对应的位置，包括多个坩埚和填充在坩埚周围的坩埚区段电阻颗粒；
    下区段，设置坩埚区段下方炉腔内，包括下电阻颗粒层；以及
    上区段，设置坩埚区段上方炉腔内，包括上电阻颗粒层；
    所述石墨化炉设备满足以下特征a至c中的至少一种：
    a.所述下区段的下端还设置有保护层；
    b.所述电阻颗粒的平均粒径范围为0至30mm，且不包括0mm；
    c.所述石墨化炉设备为用于生产石墨烯膜的艾奇逊石墨化炉。
  15. 根据权利要求14所述的石墨化炉设备，其特征在于，所述石墨化炉设备满足以下特征a至k中的至少一种：
    a.所述下电阻颗粒层包括至少两层，且各层所述电阻颗粒层的颗粒平均粒径由上层至下层逐层递减；
    b.所述上电阻颗粒层包括至少四层，且各层所述电阻颗粒层的颗粒平均粒径由下层至上层逐层递减；
    c.所述下电阻颗粒层包括两层，包括由上层至下层依次铺设颗粒的平均粒径范围在8mm～30mm和小于等于2mm的电阻颗粒层；
    d.所述上电阻颗粒层包括四层，包括由下层至上层依次铺设颗粒的平均粒径范围在8mm～30mm、5mm～10mm、2mm～4mm以及小于等于2mm的电阻颗粒层；
    e.所述坩埚区段电阻颗粒的平均粒径为8mm～30mm；
    f.所述石墨化炉设备还包括电极区段；
    g.所述石墨化炉设备还包括电极区段，电极区段设置在所述电极和所述坩埚区段之间，与所述坩埚区段对应的位置；
    h.所述电极区段中填充有电极区段电阻颗粒；
    i.所述电极区段电阻颗粒的平均粒径为≤2mm；
    j.所述电阻颗粒包括煅后石油焦、生石油焦或炭黑中的至少一种；
    k.所述坩埚内铺设有还原氧化石墨烯膜。
  16. 如权利要求13所述的电子设备或者如14-15中任一项所述的石墨化炉设备用于制备石墨烯膜的用途。
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CN109626369A (zh) * 2019-01-31 2019-04-16 吴建云 一种石墨化炉关于焙烧工艺的应用
CN111232962A (zh) * 2020-01-17 2020-06-05 深圳垒石热管理技术有限公司 一种制备超厚石墨烯散热膜的方法
CN111907096A (zh) * 2020-07-10 2020-11-10 深圳市展旺新材料科技有限公司 一种石墨烯导热膜的制备方法
CN113480312A (zh) * 2021-08-06 2021-10-08 深圳市深瑞墨烯科技有限公司 石墨烯膜及其制备方法

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CN116281995B (zh) * 2023-03-22 2024-01-30 宁夏碳谷能源科技股份有限公司 负极材料石墨化预处理方法
CN116907213A (zh) * 2023-07-21 2023-10-20 大连宏光锂业有限责任公司 一种带有石墨纸的新型节能坩埚
CN116907213B (zh) * 2023-07-21 2024-02-09 大连宏光锂业有限责任公司 一种带有石墨纸的节能坩埚
CN116697750A (zh) * 2023-08-08 2023-09-05 沈阳铝镁设计研究院有限公司 一种艾奇逊石墨化炉及装炉方法
CN116697750B (zh) * 2023-08-08 2023-11-28 沈阳铝镁设计研究院有限公司 一种艾奇逊石墨化炉及装炉方法

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