PPTC heaters and materials with stable power and self-limiting characteristics

Abstract

Polymeric positive temperature coefficient (PPTC) heaters and materials having stable power and self-limiting properties are disclosed, the polymeric positive temperature coefficient (PPTC) materials may include a polymeric matrix defining a PPTC body; and a graphene filler component disposed in the polymer matrix, where the graphene filler component includes a plurality of graphene particles aligned along a predetermined plane of the PPTC body.

Description

[0001] This application is a divisional application of the Chinese patent application with application number "202080097583.8", application date "February 25, 2020", and title "PPTC heater and material with stable power and self-limiting characteristics". Technical Field

[0002] Embodiments relate to the field of resistive heaters, and more particularly to heaters based on PPTC materials. Background Art

[0003] In various applications, polymer positive temperature coefficient (PPTC) devices can be used as overcurrent or overtemperature protection devices and current or temperature sensors. For polymer positive temperature coefficient materials, the resistance increases with increasing temperature due to the thermal expansion of the polymer matrix containing dispersed conductive materials (fillers) (such as conductive metal particle phases, or conductive carbon particle phases or ceramic conductive phases). At the trip temperature, where the polymer matrix may undergo a phase change (such as a melting transition), the accompanying large increase in polymer volume may produce a sharp increase in resistance because the conductive filler particles separate from each other, resulting in an interruption of the conductive path. After cooling, as the polymer volume shrinks, the resistivity of the PPTC material may return to a relatively low value below the trip temperature. This behavior makes PPTC materials suitable for applications such as resettable fuses. In general, the overall conductivity and resistance increase of PPTC materials with temperature depends on the content of conductive fillers, where for high resistivity (10-10000 ohm cm) PPTC materials, because the conductive filler content is low, the resistance tends to increase to a greater extent with increasing temperature even below the trip temperature. The increase in resistance below the trip temperature will cause more IR heating of the PPTC material and may cause the PPTC device to trip abnormally. Therefore, for applications where stable electrical operation below the trip temperature is useful, known PPTC materials may have limited use.

[0004] It is with respect to this and other considerations that the present disclosure is provided. Summary of the invention

[0005] In one embodiment, a polymer positive temperature coefficient (PPTC) material may include a polymer matrix defining a PPTC body; and a graphene filler component disposed in the polymer matrix, wherein the graphene filler component includes a plurality of graphene particles aligned along a predetermined plane of the PPTC body.

[0006] In another embodiment, the resistive heater may include a polymer positive temperature coefficient (PPTC) material arranged to define an annular shape of a heater body; and an electrode assembly including two or more electrodes arranged to contact the heater body at two or more locations, wherein the PPTC material includes: a polymer matrix, the polymer matrix defining the PPTC body; and a graphene filler component disposed in the polymer matrix, wherein the graphene filler component includes a plurality of graphene sheets aligned along a plane of the heater body.

[0007] In another embodiment, a method of forming a resistive heater may include providing a polymer powder; mixing a graphene sheet component and / or a carbon nanotube component with the polymer powder to form a PPTC material; heating the PPTC material to form a hot melt, wherein the graphene sheet component is uniformly dispersed in a polymer matrix formed by the polymer powder; extruding the hot melt to form a PPTC sheet; laminating the PPTC sheet between a top foil and a bottom foil to form a PPTC body; and singulating the PPTC body to form a PPTC resistive heater component. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A PPTC component according to an embodiment of the present disclosure is shown;

[0009] Figure 2 Another PPTC component according to an embodiment of the present disclosure is shown;

[0010] Figure 3 shows the resistance of an exemplary PPTC material as a function of temperature according to an embodiment of the present disclosure;

[0011] Figure 4 A schematic diagram showing the processing of a PPTC component according to an embodiment of the present disclosure;

[0012] Figure 5 An exemplary processing flow is depicted;

[0013] Fig. 6A and Figure 6B respectively show exemplary resistance and power curves as a function of temperature for an exemplary resistive heater according to an embodiment of the present disclosure;

[0014] Fig. 7A and Figure 7B respectively show exemplary resistance and power curves as a function of temperature for another exemplary resistive heater according to an embodiment of the present disclosure;

[0015] Figure 7C and Fig.7D respectively show exemplary resistance and power curves as a function of temperature for another exemplary resistive heater according to an embodiment of the present disclosure;

[0016] Figure 8 shows an exemplary power curve as a function of temperature for another exemplary resistive heater according to an embodiment of the present disclosure;

[0017] Fig. 8A An exemplary test circuit for measuring electrical characteristics of a PPTC device is depicted;

[0018] Fig. 9 shows a power curve as a function of temperature for a reference exemplary heater;

[0019] Fig. 10A depicts a side view of an exemplary PPTC resistive heater according to an embodiment of the present disclosure;

[0020] Fig. 10B and Fig. 10C Depicted in plan Fig. 10A Alternative variations of the resistive heater components;

[0021] Fig.11 A circuit depiction of an exemplary PPTC-based resistive heater is provided;

[0022] Fig.12 depicts an exemplary PPTC-based resistive heater component according to an embodiment of the present disclosure;

[0023] Fig.13 A circuit depiction of an exemplary PPTC-based resistive heater is provided;

[0024] Fig.14 depicts an exemplary PPTC resistive heater according to an embodiment of the present disclosure;

[0025] Fig.15A depicts a cross section of a novel camera according to an embodiment of the present disclosure; and

[0026] Fig. 15B Plan and perspective views of components of a heater according to an embodiment of the present disclosure are depicted. DETAILED DESCRIPTION

[0027] The present embodiment will now be described more fully below with reference to the accompanying drawings, in which exemplary embodiments are shown. The embodiments should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and its scope is fully conveyed to those skilled in the art. In the accompanying drawings, like numbers always refer to like elements.

[0028] In the following description and / or claims, the terms "on ...", "placed on ...", "disposed on ...", and "above ..." may be used in the following description and claims. "On ...", "placed on ...", "disposed on ...", and "above ..." may be used to indicate that two or more elements are in direct physical contact with each other. In addition, the terms "on ...", "placed on ...", "disposed on ...", and "above ..." may mean that two or more elements are not in direct contact with each other. For example, "above ..." may mean that one element is located above another element without contacting each other, and may have another element or elements between the two elements. In addition, the term "and / or" may mean "and", it may mean "or", it may mean "exclusive-or", it may mean "one", it may mean "some, but not all", it may mean "neither", and / or it may mean "both", although the scope of the claimed subject matter is not limited in this regard.

[0029] In various embodiments, a novel PPTC material is provided, including a conductive filler having a nanoscale carbon filler material, such as single-walled carbon nanotubes, multi-walled carbon nanotubes, or graphene. The PPTC material may include a polymer matrix, such as polyethylene, polyethylene copolymers, polyesters, polyurethanes, polyamides, fluorine-based polymer resins, or blends of fluorine-containing polymers with other polymers. In various non-limiting embodiments, the PPTC material may include antioxidants, dispersants, cross-linking agents, arc extinguishing agents, and the like. As described in detail below, the PPTC material of this embodiment provides the advantage of having stable power within a temperature range from room temperature to a maximum operating temperature, wherein the power may vary by less than 60%, such as 50%-60%, or in some embodiments, less than 30%, such as between 20% and 30%.

[0030] Particular embodiments are based on a polymer positive temperature coefficient (PPTC) material formed of a graphene filler and a semi-crystalline polymer matrix. The stable resistance characteristics imparted by such PPTC materials provide new applications, such as resistive heaters employing PPTC components. The stable resistance characteristics result in stable heater power characteristics that vary with temperatures below the melting point of the polymer matrix, which is typically associated with the trip temperature of the PPTC component. Another advantage is uniform and efficient heat transfer. In addition, since the resistivity and trip temperature can be adjusted by adjusting the type of polymer, the conductive filler, and the volume fraction of the conductive filler, the power consumption and power limit temperature can be customized according to the application of the resistive heater.

[0031] In certain embodiments, the PPTC material may be arranged as a polymer matrix having a shape and size defining a PPTC body, depending on the desired application. As an example, the PPTC heater may be arranged as a planar heater, including a ring heater or other suitable shape. The PPTC material may also include a graphene filler component disposed in the polymer matrix, wherein the graphene filler component is formed of a plurality of graphene sheets aligned along a predetermined plane of the PPTC body, such as a major plane of an annular PPTC component.

[0032] While in some embodiments the PPTC material may include a conductive filler formed solely of a graphene filler, in other embodiments a second conductive filler, such as a known carbon filler, may be added in addition to the graphene filler. Figure 1 A PPTC component according to an embodiment of the present disclosure is shown. The PPTC component 100 includes a PPTC body 102, which in turn includes a polymer matrix 104 and a graphene filler 106, which is dispersed as microscopic flakes within the polymer matrix 104. The PPTC component 100 also includes a pair of opposing electrodes, shown as electrodes 108, where an external voltage can be applied to drive current through the PPTC body 104 between the opposing electrodes. Non-limiting examples of suitable polymers for the polymer matrix 104 include semi-crystalline polymers such as polyethylene, polyvinylidene fluoride, ethylene tetrafluoroethylene, ethylene vinyl acetate, ethylene and acrylic acid copolymers, ethylene butyl acrylate copolymers, and polyperfluoroalkoxy.

[0033] In some embodiments, the volume percentage of the polymer matrix in the PPTC body 102 can be between 50% and 99%, and in specific embodiments between 60% and 95%. In various non-limiting embodiments, the volume fraction of graphene can vary from 1% to 50%, and in specific embodiments, from 4% to 30%. The graphene used for the graphene filler 106 can be prepared by mechanical or chemical means, wherein the graphene particles are formed by layers of graphene sheets, wherein according to various embodiments, the number of graphene sheets varies from one to several hundred within the particle, and in specific embodiments from one layer to about 30 layers. Therefore, the graphene particles formed by multiple graphene sheets can also have a two-dimensional sheet shape. According to some embodiments, the resulting graphene particle size can vary from 0.1 μm to 100 μm, and in particular from 1 μm to 30 μm.

[0034] As background, graphene is a crystalline allotrope of carbon with two-dimensional properties. Carbon atoms are densely packed in a regular atomic-scale hexagonal pattern in graphene. Graphene has a power of 1500-2500 W·m -1 ·K -1 High thermal conductivity in the range. Figure 1In an embodiment of the present invention, the graphene filler is arranged as flake particles, wherein the particles (referring to the plane of the flake) are generally aligned along a predetermined plane of the PPTC body 104 (such as along the XY plane of the Cartesian coordinate system shown). The high thermal conductivity of the graphene filler 106 allows for efficient heat transfer to the environment along the Z direction, as well as uniform heat transfer in the XY plane. These thermal properties are particularly useful for heater applications. In addition, the graphene flakes have a thermal conductivity as low as 10 -6 The bulk resistivity of most conductive metals is close to 2x10 -6 In addition, the graphene 2D structure allows the semi-crystalline polymer in the polymer matrix 104 to contact both sides of the graphene particles, so that when the polymer matrix 104 reaches the melting point, the PPTC material can respond to the temperature synchronously.

[0035] Figure 2 Another PPTC component 120 according to an embodiment of the present disclosure is shown. In this example, the PPTC component 120 can be arranged substantially the same as the PPTC component 100 described above, where similar components are labeled the same. The PPTC component 120 differs from the PPTC component 100 in that the PPTC body 112 also includes a conductive component 110, which can be a carbon filler and / or a ceramic conductive component, as a plurality of carbon particles or ceramic conductive particles (such as TiC or WC) disposed within the polymer matrix 104. Therefore, the conductive component 110 can modify the electrical characteristics of the PPTC component 120 relative to the electrical characteristics of the PPTC component 100.

[0036] Figure 3 FIG. 4 shows the resistance of an exemplary PPTC material according to an embodiment of the present disclosure as a function of temperature. In this case, two different curves represent Figure 1 and Figure 2 The characteristics of two different PPTC materials are generally arranged respectively. The lower curve corresponds to PPTC component 100, while the upper curve corresponds to PPTC component 120. In both examples, the resistance is relatively low and stable from room temperature to about 140°C-150°C, while increasing rapidly at the trip temperature of 170°C. For the pure graphene component, the resistance increases to 900 ohms or more, while for the PPTC component with graphene and carbon filler, the resistance increases to 24,000 ohms or more. It is worth noting that in both examples, the low temperature resistance below the trip temperature is very stable.

[0037] Figure 4A schematic diagram of the processing of a PPTC component according to an embodiment of the present disclosure is shown. To form a suitable PPTC component, such as for a heater application, the PPTC material can be extruded in an extrusion device to form a PPTC layer or sheet. Typically, a PPTC material 220 (such as a mixture of a polymer material and graphene particles) can be added to a container 202 coupled to an extrusion chamber 204, where the PPTC material 220 can be mixed, heated and stretched by an extrusion component 206 to form a PPTC body 210 in the form of a sheet or layer.

[0038] Figure 5 An exemplary process flow 302 is depicted. At box 302, a polymer material and a conductive powder and optional additives are mixed together. The polymer material may be a powder of a semi-crystalline polymer, and the conductive filler includes graphene particles, and may optionally also include carbon particles and / or conductive ceramic particles. At box 304, a hot melt process is performed, wherein the mixed components such as polymers and conductive fillers are heated to a temperature that melts the polymer and thus disperses the conductive filler particles more evenly in the polymer matrix. At box 306, sheet extrusion is performed to form a PPTC material sheet, wherein the molten mixture of the polymer and the conductive filler is extruded to form a PPTC sheet or layer. At box 308, a conductive metal layer (foil) may be applied to the top and bottom surfaces of the extruded PPTC sheet to form a laminate. At box 310, a PPTC component or multiple PPTC components are formed by singulating the laminate to form individual components (including a PPTC body sandwiched between opposing electrodes). In some examples, the singulated PPTC body may have an annular shape, such as a circular ring, a rectangular ring, an oval ring, an elliptical ring, or a polygonal ring. At block 312, the monomerized PPTC bodies are assembled into a device, such as a heater. For example, the monomerized PPTC bodies can be attached to leads (wires) connected to opposing electrodes to form a PPTC heater. Alternatively, the heater can be incorporated into another structure, such as a camera or other structure to be heated. At block 314, an insulating coating can be applied to encapsulate the components of the PPTC heater. For example, the insulating coating can be formed by electrophoretic deposition in a chemical bath; forming a parylene coating by CVD; or forming other insulating coatings.

[0039] Now turn to Fig. 6A and Figure 6B , respectively, show exemplary resistance and power curves of an exemplary resistive heater according to an embodiment of the present disclosure as a function of temperature. The exemplary heater is formed of a PPTC material having a graphene filler and a polymer matrix. Fig. 6AAs shown, the resistance does not change substantially from 25°C to about 150°C, and then increases sharply above 170°C. In contrast, power consumption remains between 3.3 W and 3 W until 100°C, gradually decreases to 1.8 W at 150°C, and decreases more sharply above 150°C to about 0.2 W at 175°C, limiting the power near the melting point of the polymer.

[0040] Fig. 7A and Figure 7B 1 and 2 show exemplary resistance and power curves as a function of temperature for another exemplary resistive heater according to an embodiment of the present disclosure. The exemplary heater is formed of a PPTC material having a graphene filler, a carbon-added filler, and a polymer matrix. Fig. 7A As shown, the resistance does not change substantially from 25°C to about 150°C, and then increases dramatically above 170°C. In contrast, power consumption decreases from 3.3 Watts to about 2.6 Watts until 100°C, and then decreases more rapidly to nearly zero Watts at 170°C. The above results show how the heater characteristics can be adjusted by adding carbon to the graphene-based PPTC body.

[0041] In other embodiments of the present disclosure, the PPTC heater may be formed of a PPTC material having a filler formed of a carbon nanotube material, such as a single-wall or multi-wall carbon nanotube material. Figure 7C and Fig.7D 2 and 3 show exemplary resistance and power curves as a function of temperature for another exemplary resistive heater according to an embodiment of the present disclosure. The exemplary heater is formed of a PPTC material having a carbon nanotube filler and a polymer matrix. Fig.7D As shown, below 150°C, the power level is relatively more stable than that of the carbon filler based PTC heater, as shown below Fig. 9 discussed.

[0042] Figure 8 An exemplary power curve as a function of temperature is shown for another exemplary resistive heater according to an embodiment of the present disclosure. Fig. 8A An exemplary test circuit for measuring the electrical characteristics of a PPTC device is depicted. Figure 8 In Figure 1, two power curves are shown, one for 16V applied to the heater and the other for 13.5V applied to the heater. The higher voltage case is shown driving higher power (compare 3.4 Watts vs. 2.4 Watts). However, for both cases, the power remains nearly constant between 20°C and 140°C, then decreases rapidly above 150°C before reaching power levels below 1 Watt above 170°C. The power reduction above 150°C reflects the tripping of the PPTC heater, where the resistance increases rapidly, limiting the current and total power for a given applied voltage. Therefore, Figure 8 The PPTC material heater element has the function of providing uniform power over a large temperature range before decreasing to limited power above the trip temperature.

[0043] As a comparison, Fig. 9 The power curve as a function of temperature for a reference heater based on a PPTC without graphene filler is shown. Fig. 9 In FIG. 1 , two power curves are also shown, one for applying 16V to the heater and the other for applying 13.5V to the heater. The higher voltage case is shown to drive higher power (compare 2.1 Watts to 1.5 Watts). However, for both cases, the power continues to drop significantly between 20°C and 140°C, reaching essentially zero Watts above 150°C. Therefore, such a resistive heater will not exhibit stable power output over a useful temperature range (such as below the trip temperature, between room temperature and 150°C).

[0044] According to various embodiments of the present disclosure, the PPTC heater may be suitable for use in components such as cameras. Figure 10A-Figure 1 In the following embodiments of FIG. 5, novel configurations of PPTC resistive heaters are shown, including incorporating PPTC resistive heaters into cameras. According to various embodiments, the PPTC resistive heaters may be based on known PPTC materials, such as carbon-filled polymers, or may be based on graphene-filled polymers, as generally described in the foregoing embodiments. Graphene-filled polymer-based PPTC heaters may be particularly suitable for applications where stable current operation over an extended temperature range is required.

[0045] Fig. 10A 3 shows a side view of an exemplary PPTC resistive heater 350 according to an embodiment of the present disclosure. The resistive heater 350 includes a PPTC resistive heater component 360 and an external lead 370. For example, the resistive heater component may be substantially as described above with respect to Figure 1-Figure 2 When viewed in plan, the resistive heater component 360 may have an annular shape so as to border the periphery of the component to be heated (such as a camera). The arrows depict the current path of the current flowing from the left wire 370 through the PPTC resistive heater component 360 and out of the right wire 370. Fig. 10B and Fig. 10C An alternative variation of a resistive heater component 360 is depicted in plan view. The resistive heater component 360 includes a PPTC body 362 arranged as a toroidal body and an opposing electrode shown as electrode 364. For example, Fig. 10BAs shown, the resistive heater component 360A is arranged with opposing electrodes (such as two annular segments), shown as segment 364A and segment 364B, wherein a portion of the annular body is exposed as shown in exposed area 362A and exposed area 362B. Fig. 10A and Fig. 10B The configuration differs from one another in the relative placement of segments 364A and 364B to one another and in the shapes and sizes of exposed areas 362A and 362B. Due to this configuration, as Fig. 10A As shown, current flowing through the least resistance path can flow vertically from the left conductor 370 to the lower portion of the electrode 364, and then flow laterally along the lower surface of the PPTC body along the electrode 364. The break in the electrode 364 can then cause the current to flow vertically to the upper surface, then flow laterally along the upper surface, flow vertically from the upper surface of the PPTC body to the lower surface, flow laterally along the lower electrode, and flow vertically out of the right conductor 370.

[0046] Fig.11 A circuit depiction of an exemplary PPTC-based resistive heater of FIG. 10 is provided. Components R0 and R7 indicate resistance from wire 370. Components R1, R4, and R6 indicate resistance from foil, while components R2, R3, and R5 indicate resistance from the PTC ring body. As shown, the resistance of component R3 may be greater than the resistance of R2 and R5 generated by the left and right sides of the PTC ring.

[0047] Fig.12 An exemplary PPTC-based resistive heater component according to an embodiment of the present disclosure is depicted, shown as PPTC heater component 400. In this example, PPTC heater component 400 has a flat annular shape, as shown in the side view (top and bottom) and plan view (middle). PPTC heater component 400 can generally be as shown. Figure 1-Figure 2 The embodiment shown in the embodiment is arranged, wherein the PPTC body is sandwiched between the opposing electrodes. In this case, the opposing electrodes can cover most of the upper ring surface and the lower ring surface.

[0048] Fig.13 Provided Fig.12 4. Circuit depiction of an exemplary PPTC-based resistive heater. Elements R0 and R7 indicate resistance from external wires to be connected to the PPTC heater 400. Elements R1, R2, R5, and R6 indicate resistance from pads, while elements R3, R4 indicate resistance from the PTC body.

[0049] Fig.14A side view of an exemplary PPTC resistive heater 450 according to an embodiment of the present disclosure is depicted. The resistive heater 450 includes a PPTC resistive heater component 400 and an external lead 410. Arrows depict the current path of current flowing from the left lead 410 through the PPTC resistive heater component 400 and out of the right lead 410. As shown, the current can flow from the left lead 410 vertically from the lower surface of the PPTC body to the upper surface, then flow laterally along the upper electrode, flow vertically from the upper surface to the lower surface of the PPTC body, flow laterally along the lower electrode, and flow out of the right lead 410.

[0050] In various embodiments, the PPTC heater can be incorporated into a printed circuit board (PCB). For example, the resistive heater component 400 can be incorporated into a resistive heater using a PCB to support a surface mount PTC resistive heater configuration.

[0051] As described above, the PPTC resistance heater according to the present embodiment may be incorporated into a camera. Fig.15A A novel camera 450 is depicted, including a PPTC resistive heater component 400A arranged as a ring to be incorporated into a camera lens assembly. The PPTC resistive heater component 400A can be in thermal contact with a camera lens 430 to heat the camera lens by resistive heating. Due to the ring shape, the outer periphery of the camera lens 430 can be directly heated. In this way, for example, the camera lens can be heated to a given amount to remove moisture or precipitation.

[0052] exist Fig.15A In a specific embodiment of the present invention, the heater component 400A can conduct current, as shown in the heater component 400 discussed above. The heater component 400A includes a PTC body 412, a metal foil layer 414, a conductive metal portion 418, and an insulating layer 416. The heater component 400A can be connected to the wire 410 through the contact metal 419. Fig. 15B A plan view of the heater component 400A is shown in FIG. Fig.15A The top of the Fig. 15B The cross section of the semicircular path AA is shown. Therefore, the heater component 400A can be arranged according to the surface mounting technology. In particular, the heater component 400A can be supported on the PCB ring 420, wherein the heater component 400A and the PCB ring 420 have an annular shape, such as Fig. 15B The heater component 400A may be divided into two sections as shown in the figure to produce a generally Fig.14The current path shown. It is worth noting that the current between the wires 410 can travel in two semicircular parallel paths. In various non-limiting embodiments, the total thickness of the heater component 400A can be about 2 mm, while the thickness of the PCB ring 420 is less than 1 mm. Non-limiting examples of suitable materials for the PCB ring 420 include FR4, copper inlay PCB, or ceramic PCB, such as Al 2 O 3 or AlN.

[0053] When a PPTC resistive heater according to the present embodiment is incorporated into a camera or other device to be heated, the following advantages can be achieved: 1) a self-balancing power distribution design; 2) a thin but completely insulated component from the camera housing; 3) a heater of a special shape that can fit into very narrow areas; 4) a component in which the power and temperature performance of the resistive heater can be adjusted by adjusting the filler formulation (such as the volume fraction of graphene particles (for graphene-based PPTC materials), and optional carbon particles added to the polymer matrix); 5) a resistive heater with stable power generation and temperature operation over a wide temperature range (for graphene-based PPTC materials), such as to the maximum operating temperature; 6) higher power generation in colder environments; 7) lower power generation in warmer environments; and 8) a resistive heater with self-limiting power.

[0054] Although the present embodiment has been disclosed with reference to certain embodiments, many modifications, variations and changes to the described embodiments are possible without departing from the field and scope of the present disclosure as defined by the appended claims. Therefore, the present embodiment is not limited to the described embodiments, and may have the full scope defined by the language of the following claims and their equivalents.

Claims

1. A polymer positive temperature coefficient body for use in a heater, comprising: a polymer matrix comprising a polymer positive temperature coefficient (PPTC) material, wherein the polymer matrix is ​​arranged in a flat annular shape lying in a plane, Wherein, the PPTC body has an upper surface and a lower surface; and A graphene filler component is disposed in the polymer matrix, wherein the graphene filler component includes a plurality of graphene particles composed of graphene sheets, wherein the plurality of graphene sheets are aligned along the plane.

2. The polymer positive temperature coefficient body of claim 1, further comprising at least one electrode disposed on the upper surface of the PPTC body, and at least one additional electrode disposed on the lower surface of the PPTC body.

3. The polymer positive temperature coefficient body according to claim 1, wherein: The flat annular shape includes a circular ring, a rectangular ring, an oval ring, an elliptical ring, or a polygonal ring.

4. The polymeric positive temperature coefficient body of claim 1, further comprising a carbon filler component disposed as a plurality of carbon particles within the polymer matrix.

5. The polymer positive temperature coefficient body according to claim 1, wherein: The volume percentage of the polymer matrix is ​​between 50% and 99%.

6. The polymer positive temperature coefficient body according to claim 1, wherein: The volume percentage of the graphene filler component is between 1% and 50%.

7. The polymeric positive temperature coefficient body of claim 1 further comprising a carbon nanotube filler component.

8. A polymeric positive temperature coefficient body for use in a heater, comprising: a polymer matrix comprising a polymer positive temperature coefficient (PPTC) material, wherein the polymer matrix is ​​arranged in a flat annular shape lying in a plane, Wherein, the PPTC body has an upper surface and a lower surface; and The carbon nanotube filler component is disposed in the polymer matrix, wherein the carbon nanotube filler component comprises a single-walled carbon nanotube material or a multi-walled carbon nanotube material.

9. The polymeric positive temperature coefficient body of claim 8, further comprising at least one electrode disposed on the upper surface of the PPTC body, and at least one additional electrode disposed on the lower surface of the PPTC body.

10. The polymer positive temperature coefficient body according to claim 8, wherein: The flat annular shape includes a circular ring, a rectangular ring, an oval ring, an elliptical ring, or a polygonal ring.

11. The polymer positive temperature coefficient body according to claim 8, wherein: The volume percentage of the polymer matrix is ​​between 50% and 99%.

12. The polymeric positive temperature coefficient body of claim 8, further comprising a graphene filler component.

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