Graphitization furnace and preparation device of battery

Abstract

The embodiment of the utility model provides a graphitization furnace and a preparation device of a battery. The graphitization furnace comprises a furnace body provided with a material channel; the first electrode extends in the first direction and penetrates through the material channel, and the first direction is perpendicular to the extending direction of the material channel; the second electrode and the first electrode are arranged in a spaced mode, and the second electrode is arranged around the material channel; wherein the polarity of the first electrode is opposite to that of the second electrode, at least one part of the surface of the first electrode and at least one part of the surface of the second electrode are oppositely arranged, and a part of the material channel is formed between the at least one part of the surface of the first electrode and the at least one part of the surface of the second electrode. According to the graphitization furnace and the preparation method of the battery in the embodiment of the invention, the consistency of products can be improved.

Description

Technical Field

[0001] This application relates to the field of graphite processing technology, and in particular to a graphitization furnace and a battery preparation apparatus. Background Technology

[0002] The carbon atoms in carbonaceous materials are arranged irregularly. Only through high-temperature heat treatment, causing the carbon atoms to recrystallize and rearrange in an ordered manner, can the crystalline structure of graphite be presented. This results in graphite possessing many of graphite's excellent properties, such as significantly improved electrical and thermal conductivity, better chemical and thermal stability, reduced impurities, lower hardness, and easier machining. The function of a graphitization furnace is to transform carbonaceous materials into artificial graphite materials, providing high-quality carbon-based graphite materials for industries such as steel smelting, aluminum smelting, anode materials, other non-ferrous metal industries, and the nuclear industry.

[0003] Traditional graphitization furnaces suffer from problems such as the inability to centralize heating and poor product consistency. Utility Model Content

[0004] In view of this, embodiments of this application provide a graphitization furnace and a battery preparation apparatus that can improve product consistency.

[0005] In a first aspect, a graphitization furnace is provided, comprising: a furnace body having a material channel; a first electrode extending along a first direction and passing through the material channel, the first direction being perpendicular to the extension direction of the material channel; and a second electrode spaced apart from the first electrode and disposed around the material channel; wherein the first electrode and the second electrode have opposite polarities, at least a portion of the surface of the first electrode is disposed opposite to at least a portion of the surface of the second electrode, and a portion of the material channel is formed between the at least a portion of the surface of the first electrode and the at least a portion of the surface of the second electrode.

[0006] In this embodiment, at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode are disposed opposite to each other, such that the core heating area is distributed between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode. Since at least a portion of the material channel is formed between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode, when the material flows along the extension direction of the material channel in the furnace, it will inevitably pass through the core heating area between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode. This helps to keep the graphitization degree of the material consistent in the graphitization furnace and improves the consistency of the product.

[0007] In one possible implementation, the first surface of the first electrode and the second surface of the second electrode are arranged radially opposite each other along the material channel.

[0008] In this embodiment, the first surface of the first electrode and the second surface of the second electrode are arranged opposite to each other, so that the core heating area is distributed between the first surface and the second surface. In addition, since the first surface and the second surface are arranged opposite to each other along the radial direction of the material channel, the material will inevitably pass through the core heating area between the first surface and the second surface when it flows along the extension direction. This can ensure that the graphitization degree of the material in the graphitization furnace is consistent and improve the consistency of the product.

[0009] In one possible implementation, the first surface and the second surface are parallel to each other, and / or both the first surface and the second surface are parallel to the direction of extension of the material channel.

[0010] In this embodiment, the first surface and the second surface are set to be parallel to each other, and / or both the first surface and the second surface are parallel to the extension direction of the material channel, so that the electric field distribution formed between the first surface and the second surface is uniform, thereby making the heating degree of the material at all points between the first surface and the second surface consistent and improving the consistency of the product; in addition, since the electric field distribution formed between the first surface and the second surface is uniform, it can also reduce coking caused by the temperature inconsistency of the material at all points between the first surface and the second surface, thereby improving the flowability of the material in the furnace.

[0011] In one possible implementation, the second electrode includes at least one pair of electrode posts extending radially along the material channel, with two electrode posts in each pair of electrode posts respectively disposed on both sides of the first electrode.

[0012] In this embodiment, the second electrode includes paired electrode posts, which can increase the heating area of ​​the material and make the material in all places heated, thereby improving the consistency of the product.

[0013] In one possible implementation, the two electrode posts in each pair are arranged symmetrically with respect to the first electrode.

[0014] In this embodiment, the two electrode posts in each pair are symmetrically arranged relative to the first electrode, which makes the two heating regions formed between the two electrode posts in each pair and the first electrode symmetrical relative to the first electrode. This is beneficial for the electric field distribution of the two symmetrical heating regions to be uniform when the electrode posts are controlled in pairs, thereby improving the heating uniformity of the material after passing through the two symmetrical heating regions and improving the consistency of the product.

[0015] In one possible implementation, an insulating element is provided between the second electrode and the first electrode within the furnace body along the circumference of the material channel.

[0016] In this embodiment, an insulating element is provided between the first electrode and the second electrode along the circumference of the material channel. On the one hand, this can restrict the material channel so that the material can only pass through the heating area between the first surface and the second surface, thereby improving the consistency of the product. On the other hand, it can also reduce the possibility of forming an electric field in the area outside the graphitized region.

[0017] In one possible implementation, the graphitization furnace further includes a third electrode, which is spaced apart from the first electrode along the extension direction of the material channel, and is arranged around the material channel, wherein the third electrode and the first electrode have opposite polarities.

[0018] In one possible implementation, the third surface of the first electrode and the fourth surface of the third electrode are disposed opposite each other along the extension direction of the material channel, and a portion of the material channel is formed between the third surface and the fourth surface.

[0019] In this embodiment, the first surface of the first electrode and the second surface of the second electrode are arranged opposite each other along the radial direction of the material channel, and the third surface of the first electrode and the fourth surface of the third electrode are arranged opposite each other along the extension direction of the material channel, so that the material can be heated between the first surface and the second surface and between the third surface and the fourth surface during the flow process, thereby improving the graphitization degree of the material.

[0020] In one possible implementation, the third and fourth surfaces are parallel to each other, and / or both the third and fourth surfaces are perpendicular to the direction of extension of the material channel.

[0021] In this embodiment, the third and fourth surfaces are set to be parallel to each other, and / or both the third and fourth surfaces are parallel to the extension direction of the material channel, so that the electric field distribution formed between the third and fourth surfaces is uniform, thereby making the heating degree of the material at all points between the third and fourth surfaces consistent and improving the consistency of the product.

[0022] In one possible implementation, the third electrode includes an electrode ring arranged around the material channel, and the fourth surface is annular in shape.

[0023] In this embodiment, the third electrode includes an electrode ring, which is arranged around the material channel. This allows the heating area between the first and third electrodes to be arranged around the entire circumference of the material channel, improving the uniformity of heating of the material during the flow process and thus improving the consistency of the product.

[0024] In one possible implementation, the orthographic projection of the third surface onto a plane perpendicular to the extension direction of the material channel completely covers the orthographic projection of the fourth surface onto the plane.

[0025] In this embodiment, the orthographic projection of the third surface on a plane perpendicular to the extension direction of the material channel completely covers the orthographic projection of the fourth surface on a plane perpendicular to the extension direction of the material channel. This is beneficial for increasing the heating area between the first electrode and the third electrode while maximizing the flowability of the material within the third electrode.

[0026] In one possible implementation, the projected area of ​​the third surface on a plane perpendicular to the extension direction of the material channel is S1, and the area of ​​the portion of the fourth surface projected on a plane perpendicular to the extension direction of the material channel and overlapping with the third surface is S2, wherein the ratio of S2 to S1 is 0.2 to 0.5.

[0027] In this embodiment, if the ratio of S2 to S1 is less than 0.5, the heating area between the third and fourth surfaces may be small, failing to achieve the effect of further heating the material between the first and third electrodes. If the ratio of S2 to S1 is greater than 0.5, the cavity in the electrode ring may be too small, insufficient for the material to flow smoothly through the cavity. Setting the ratio of S2 to S1 to 0.2 to 0.5 is beneficial for balancing the heating effect and the flowability of the material.

[0028] In one possible implementation, the ratio of S2 to S1 is 1 / 3.

[0029] In this embodiment, setting the ratio of S2 to S1 to 1 / 3 allows for a balance between the heating effect and the flowability of the material.

[0030] In one possible implementation, the first electrode is a square columnar electrode, and in the second direction, the ratio of the size of the first electrode to the inner diameter of the electrode ring is 1.2 to 2. The second direction is perpendicular to the first direction and also perpendicular to the extension direction of the material channel.

[0031] In this embodiment, in the second direction, if the ratio of the size of the first electrode to the inner diameter of the electrode ring is less than 1.2, the heating area between the third and fourth surfaces may be small, failing to achieve the effect of further heating the material between the first and third electrodes. If the ratio of the size of the first electrode to the inner diameter of the electrode ring is greater than 2, the cavity inside the electrode ring may be too small, insufficient for the material to flow smoothly through the cavity. Setting the ratio of the size of the first electrode to the inner diameter of the electrode ring to 1.2 to 2 is beneficial for balancing the heating effect and the flowability of the material.

[0032] In one possible implementation, in this second direction, the ratio of the size of the first electrode to the inner diameter of the electrode ring is 1.5 to 2.

[0033] In this embodiment, in the second direction, the ratio of the size of the first electrode to the inner diameter of the electrode ring is set to 1.5 to 2, which enables the heating effect and flowability of the material to be balanced.

[0034] In one possible implementation, the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces is 0.2 to 1.

[0035] In this embodiment, if the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces is less than 0.2, the distance between the third and fourth surfaces may be too large, resulting in a weak electric field between them, which fails to achieve the effect of further heating the material between the first and third electrodes. If the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces is greater than 1, the material may flow out before it has had time to be heated in the heating area between the third and fourth surfaces after flowing through the heating area between the first and second surfaces, which also fails to achieve the effect of further heating the material between the first and third electrodes. Setting the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces to 0.2 to 1 is beneficial to improving the heating effect of the material between the third and fourth surfaces.

[0036] In one possible implementation, the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces is 0.5 to 1.

[0037] In this embodiment, the ratio of the distance between the first and second surfaces to the distance between the third and fourth surfaces is set to 0.5 to 1, which can improve the heating effect of the material between the third and fourth surfaces, thereby improving the graphitization degree of the material.

[0038] In one possible implementation, the second electrode is closer to the inlet of the material channel than the third electrode.

[0039] In one possible implementation, the first surface of the first electrode and the second surface of the second electrode are disposed opposite each other along the extension direction of the material channel.

[0040] In one possible implementation, the graphitization furnace further includes: a furnace lining, arranged around the inner wall of the furnace body; wherein both the first electrode and the second electrode pass through the furnace lining and are connected to a power source outside the furnace body.

[0041] In this embodiment, an inner lining is provided around the inner wall of the furnace body, which can provide heat insulation and heat preservation for the high temperature inside the furnace body.

[0042] In one possible implementation, the furnace lining includes an insulation layer and a heat-resistant layer, with the heat-resistant layer surrounding the insulation layer and the thermal conductivity of the insulation layer being lower than that of the heat-resistant layer.

[0043] In this embodiment, a multi-layer heat-insulating furnace lining is provided, which can improve the service life of the graphitization furnace. In addition, setting the thermal conductivity of the insulation layer to be lower than that of the heat-resistant layer can improve the heat insulation effect while reducing the cost of the graphitization furnace.

[0044] In one possible implementation, the first electrode is a graphite electrode, and / or the second electrode is a graphite electrode.

[0045] In one possible implementation, the material channel extends in a vertical direction.

[0046] In a second aspect, a battery fabrication apparatus is provided, comprising a graphitization furnace as described in the first aspect and any implementation thereof, the graphitization furnace being used to fabricate a negative electrode material for the battery. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0048] Figure 1 This is a front view of a graphitization furnace.

[0049] Figure 2 This is a schematic top view of a graphitization furnace according to an embodiment of this application.

[0050] Figure 3 This is a schematic cross-sectional view of a graphitization furnace provided in an embodiment of this application.

[0051] Figure 4 This is a schematic cross-sectional view of a graphitization furnace provided in another embodiment of this application.

[0052] Figure 5 This is a schematic top view of a graphitization furnace according to another embodiment of this application.

[0053] Figure 6 This is a schematic cross-sectional view provided in another embodiment of this application.

[0054] Figure 7 This is a schematic top view of a graphitization furnace according to another embodiment of this application.

[0055] Figure 8This is a schematic block diagram of a battery manufacturing apparatus according to an embodiment of this application.

[0056] The accompanying drawings are not drawn to scale. Detailed Implementation

[0057] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0058] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0059] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0060] With the development of new energy power, lithium-ion batteries are increasingly favored by investors, and carbon anode materials, as a key component of lithium-ion batteries, are also experiencing explosive market growth. A crucial step in the production process of carbon anode materials is graphitization. Graphitization refers to the transformation of carbon atoms from a random, irregular arrangement into a regularly arranged hexagonal planar network structure at high temperatures, i.e., the graphite microcrystalline structure. The purpose is to obtain graphite's high electrical and thermal conductivity, corrosion resistance, and abrasion resistance. During graphitization, the higher the temperature, the more complete the development of the graphite microcrystalline structure, thus increasing the degree of graphitization. The equipment used to complete graphitization is called a graphitization furnace.

[0061] Traditional graphitization furnaces typically employ an electrode pair consisting of a vertically placed columnar electrode at the center of the material channel and a horizontally placed annular electrode in the lower part of the furnace body. The columnar electrode serves as the positive electrode, while the annular electrode acts as the negative electrode. An umbrella-shaped or frustum-shaped graphitization region is formed between the lower surface of the positive electrode and the inner surface of the negative electrode. After passing through this region, the material undergoes graphitization. However, in this electrode arrangement, the electric field directly below the positive electrode is more concentrated than that on either side, resulting in the core heating area being concentrated in this region. As the material flows through the material channel, some material passes through this region directly below the positive electrode, while the rest passes through the region on either side. This uneven graphitization within the furnace leads to poor product consistency.

[0062] Therefore, this application provides a graphitization furnace in which at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode are disposed opposite each other, such that the core heating area is distributed between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode. Since a part of the material channel is formed between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode, the material will inevitably pass through the core heating area between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode when it flows in the material channel. This can ensure that the graphitization degree of the material in the graphitization furnace is consistent and can improve the consistency of the product.

[0063] Figure 1 A front view of a graphitization furnace 100 is shown. (See diagram.) Figure 1 As shown, the main body of the graphitization furnace 100 is arranged vertically, mainly including the furnace body 1 and various functional units arranged in the furnace body 1. Specifically, as... Figure 1 As shown, the graphitization furnace may include a feeding unit, a DC power supply unit, and a cooling and discharging unit.

[0064] The feeding unit mainly includes a hopper 2 and a feed pipe 3. The hopper 2 is located above the furnace body 1, and the hopper 2 is connected to the feed inlet on the furnace body through the feed pipe 3. Optionally, a material shut-off valve 4 can also be installed at the connection between the hopper 2 and the feed pipe 3 to control the flow of material in the material channel 12.

[0065] Optionally, the material entering the graphitization furnace 100 is a graphitizable carbonaceous material, such as petroleum coke, coal coke, and asphalt. After entering the graphitization furnace, the material undergoes four stages: preheating, calcination, graphitization, and cooling to complete the graphitization process and obtain the negative electrode material product. Volatile exhaust gas is released during the process.

[0066] Optionally, the number of hoppers 2 can be two, four, or more, and they are evenly distributed above the furnace body 1.

[0067] The DC power supply unit may include a positive electrode 5, a negative electrode 6, and a DC transformer 7. For example... Figure 1 As shown, the positive electrode 5 can extend into the furnace through the opening at the top of the furnace body 1 and be suspended in the material channel 12, while the negative electrode 6 can be disposed in the lower middle part of the furnace body 1. Optionally, the number of negative electrodes 6 can be at least one pair, with each pair evenly distributed at 180 degrees. Optionally, the negative electrodes 6 can be radially distributed at the same height in the furnace body 1 along the material channel 12.

[0068] The DC transformer 7 supplies power to the furnace body 1, with the power output controllable between 600 and 1200 kW. Positive electrode 5 and negative electrode 6 apply voltage to the material passing between them. DC current flows from the positive terminal of the DC transformer 7 through the material, which releases Joule heat due to its own resistance, maintaining the furnace core temperature above 3000℃, thus creating a stable temperature field between the positive electrode 5 and negative electrode 6. The current flowing through the material returns to the negative terminal of the DC transformer 7 via the negative electrode 6, forming a current flow loop.

[0069] Optionally, the DC power supply unit may further include a fixed brake 8, a conductive element 9, a cable 10, and a copper busbar 11. The positive electrode 5 is held and fixed to the top of the furnace body 1 by the fixed brake. The conductive element 9 is fixed below the fixed brake 8, conducts current to the positive electrode 5, and is connected to the copper busbar 11 by the cable 10. The copper busbar 11 connects to the positive and negative terminals of the DC transformer 7.

[0070] Optionally, the positive electrode 5 and the negative electrode 6 can be graphite electrodes.

[0071] The cooling discharge unit is mainly used to cool the graphitized material. Specifically, such as... Figure 1 As shown, the cooling discharge unit may include a low-temperature cooling section 13, which may be a water-cooled jacket. The low-temperature cooling section 13 may also be provided with a water inlet 14 and a water outlet 15, and the cooling medium may be circulating water.

[0072] Optionally, the graphitization furnace 100 may also include a furnace body heating unit (not shown in the figure). For example, a furnace cover and a furnace body lining. The furnace cover may be located on the upper part of the furnace body 1 for heat insulation, while the furnace body lining is arranged around the inner wall of the furnace body 1 to provide heat insulation for the high temperature of the furnace core.

[0073] Figure 2 A schematic top view of a graphitization furnace 200 provided in one embodiment of this application is shown. Figure 2 As shown, the graphitization furnace 200 includes: a furnace body 210, a first electrode 220, and a second electrode 230; the furnace body 210 is provided with a material channel 211; the first electrode 220 extends along a first direction X and passes through the material channel 211, the first direction X being perpendicular to the extension direction Z of the material channel 211 (see...). Figure 3 The second electrode 230 is disposed at a distance from the first electrode 220 and is disposed around the material channel 211; wherein the first electrode 220 and the second electrode 230 have opposite polarities, at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230 are disposed opposite to each other, and a portion of the material channel 211 is formed between the at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230.

[0074] First, the following points need to be explained:

[0075] First, the first electrode 220 and the second electrode 230 have opposite polarities, which can be understood as forming an electric field from the positive electrode to the negative electrode between the first electrode 220 and the second electrode 230. Second, the first electrode 220 and the second electrode 230 are spaced apart, meaning there is a gap between them, which can form a graphitized region for heating the material, hereinafter also referred to as a heating region. Third, the first electrode 220 passing through the material channel 211 means that the first electrode 220 spans the entire material channel 211 in the first direction X. Fourth, the fact that at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230 are arranged opposite each other can mean that the projections of at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230 in a certain direction at least partially overlap. Optionally, at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230 can both be planar, or both can be curved, or one can be planar and the other curved. Finally, at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230 form part of the material channel 211. It can be understood that when the material flows in the furnace body 210 along the extension direction Z of the material channel 211, it will inevitably pass through the area between at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230.

[0076] Optionally, in one embodiment, the first electrode 220 can be a positive electrode and the second electrode 230 can be a negative electrode. Optionally, in another embodiment, the first electrode 220 can be a negative electrode and the second electrode 230 can be a positive electrode. That is, the polarities of the first electrode 220 and the second electrode 230 in the embodiments of this application can be interchanged.

[0077] Optionally, if the graphitization furnace 200 is arranged vertically, i.e., the extension direction Z of the material channel 211 is vertical, then the first electrode 220 is horizontally arranged, and the second electrode 230 is also horizontally arranged. If the graphitization furnace 200 is arranged horizontally, i.e., the extension direction Z of the material channel 211 is horizontal, then the first electrode 220 is vertically arranged, and the second electrode 230 is also vertically arranged. For ease of understanding, the use of terms such as "upper" and "lower" in the following embodiments will be described with the example of a vertical graphitization furnace 200.

[0078] In this embodiment, at least a portion of the surface of the first electrode 220 is disposed opposite to at least a portion of the surface of the second electrode 230, such that the core heating region is distributed between at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230. Since a part of the material channel 211 is formed between at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230, when the material flows along the extension direction Z of the material channel 211 in the furnace body 210, it will inevitably pass through the core heating region between at least a portion of the surface of the first electrode 220 and at least a portion of the surface of the second electrode 230. This helps to keep the graphitization degree of the material consistent in the graphitization furnace and improves the consistency of the product.

[0079] Figure 3 A schematic cross-sectional view of a graphitization furnace 200 according to an embodiment of this application is shown.

[0080] Optionally, such as Figure 3 As shown, the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 are arranged opposite each other along the radial direction Y of the material channel 211, and the first surface 221 and the second surface 231 form a part of the material channel 211. In other words, when the material flows in the furnace body 210 along the extension direction Z of the material channel 211, it will inevitably pass through the region 2111 between the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230.

[0081] In this embodiment, the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 are arranged opposite to each other, such that the heating area is distributed between the first surface 221 and the second surface 231. In addition, since the first surface 221 and the second surface 231 are arranged opposite to each other along the radial Y of the material channel, the material will inevitably pass through the heating area between the first surface 221 and the second surface 231 when it flows along the extension direction Z. This ensures that the graphitization degree of the material in the graphitization furnace remains consistent, thereby improving the consistency of the product.

[0082] Figure 4A schematic cross-sectional view of a graphitization furnace 200 according to another embodiment of this application is shown. Wherein, Figure 4 The arrangement of the first electrode 220 within the furnace body 210 is similar to... Figure 2 and Figure 3 The same as in.

[0083] Optionally, such as Figure 4 As shown, the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 are arranged opposite each other along the extension direction Z of the material channel 211, and the first surface 221 and the second surface 231 form a part of the material channel 211. In other words, when the material flows in the furnace body 210 along the extension direction Z of the material channel 211, it will inevitably pass through the region 2111 between the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230. This region 2111 is the heating region in the furnace body 210.

[0084] In this embodiment, the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 are arranged opposite to each other, such that the heating area is distributed between the first surface 221 and the second surface 231. In addition, since a part of the material channel 211 is formed between the first surface 221 and the second surface 231, the material will inevitably pass through the heating area between the first surface 221 and the second surface 231 of the second electrode 230 when it flows through the material channel 211. This helps to keep the graphitization degree of the material consistent in the graphitization furnace and improves the consistency of the product.

[0085] Optionally, in this embodiment, the first surface 221 and the second surface 231 can be parallel to each other. For example, both the first surface 221 and the second surface 231 can be planes, and the distance from any point on the first surface 221 to the second surface 231 is equal. As another example, both the first surface 221 and the second surface 231 can be curved surfaces, and the circular surfaces containing the first surface 221 and the second surface 231 are coaxial.

[0086] For example, if the first electrode 220 is a square cylindrical electrode, then the first surface 221 is a plane, and the second surface 231 of the second electrode 230 can also be a plane. As another example, if the first electrode 220 is a cylindrical electrode, then the first surface 221 is an arc surface, and the second surface 231 of the second electrode 230 can also be an arc surface.

[0087] In this embodiment, the first surface 221 and the second surface 231 are arranged to be parallel to each other, so that the electric field formed between the first surface 221 and the second surface 231 is uniformly distributed, thereby making the heating degree of the material between the first surface 221 and the second surface 231 consistent and improving the consistency of the product. In addition, since the electric field formed between the first surface 221 and the second surface 231 is uniformly distributed, it can also reduce coking caused by the inconsistent temperature of the material between the first surface 221 and the second surface 231, thereby improving the flowability of the material in the furnace.

[0088] Optionally, in Figure 3 In the embodiment shown, the first surface 221 and the second surface 231 can both be parallel to the extension direction Z of the material channel 211.

[0089] Optionally, in Figure 4 In the embodiment shown, the first surface 221 and the second surface 231 can both be perpendicular to the extension direction Z of the material channel 211.

[0090] Optionally, the second electrode 230 includes at least one pair of electrode posts 232 extending radially Y along the material channel 211, with two electrode posts in each pair of electrode posts 232 respectively disposed on opposite sides of the first electrode 220. For example, as Figure 4 The second electrode 230 includes a pair of electrode posts 232, namely electrode posts 2301a and electrode posts 2301b. Electrode posts 2301a and electrode posts 2301b can be disposed at the same height as the first electrode 220 in the material channel 211, and electrode posts 2301a and electrode posts 2301b can be disposed on both sides of the first electrode 220 along the radial Y direction of the material channel 211.

[0091] Optionally, the second electrode 230 may include one, two, three, four, or any number of electrode post pairs. For example, multiple pairs of electrode posts may be arranged on both sides of the first electrode 220 along different radial directions Y of the material channel 211.

[0092] Optionally, in one embodiment, the first electrode 220 may pass through the center point of a section of the furnace body 210 perpendicular to the extension direction Z, and two electrode posts in each pair may be arranged on both sides of the first electrode 220 along different radial directions Y (other than the first direction X). Optionally, two electrode posts in one pair may be arranged on both sides of the first electrode 220 along a second direction P, where the second direction P is the radial direction Y of the material channel 211 and is perpendicular to the first direction X and the extension direction Z of the material channel 211.

[0093] Optionally, in other embodiments, the at least one pair of electrode posts 232 included in the second electrode 230 may not extend radially Y. For example, the at least one pair of electrode posts 232 may be at the same height as the first electrode 220 in the material channel 211 and disposed on both sides of the first electrode 220 in a second direction P perpendicular to the first direction X. The second direction P is not the radial Y of the material channel 211.

[0094] In other alternative implementations, the first electrode 220 may not pass through the center point of the cross section of the furnace body 210 perpendicular to the extension direction Z. In this case, the distance between the first electrode 220 and the electrode posts distributed on both sides thereon may be unequal.

[0095] In this embodiment, the second electrode 230 includes paired electrode posts, which can increase the heating area of ​​the material and make the material in all places heated, thereby improving the consistency of the product.

[0096] Optionally, in this embodiment, two electrode posts in each pair of electrode posts 232 are symmetrically arranged relative to the first electrode 220. For example, Figure 3 The electrode posts 2301a and 2301b are symmetrically arranged relative to the first electrode 220.

[0097] It should be explained that "symmetrical arrangement" here can include the graphitization region formed between the two electrode pillars in each pair and the first electrode 220 being symmetrical. The electrode pillars themselves can be asymmetrical, that is, the two electrode pillars in each pair can have different shapes and structures. For example, electrode pillar 2301a can be a square pillar, electrode pillar 2301b can be a trapezoidal pillar, and the second surfaces 2311 of electrode pillar 2301a and 2312 of electrode pillar 2301b, which are arranged opposite to the first surface 221 of the first electrode 220, can have the same shape and size. Furthermore, electrode pillars 2301a and 2301b are located at the same height as the first electrode 220 in the material channel 211, thereby making the graphitization region formed between electrode pillar 2301a and the first electrode 220 completely symmetrical with the graphitization region formed between electrode pillar 2301b and the first electrode 220.

[0098] In this embodiment, the two electrode posts in each pair of electrode posts 232 are symmetrically arranged relative to the first electrode 220, which makes the two heating regions formed between the two electrode posts in each pair of electrode posts and the first electrode 220 symmetrical relative to the first electrode 220. This is beneficial to make the electric field distribution of the two symmetrical heating regions uniform when the electrode posts are controlled in pairs, thereby improving the heating uniformity of the material after passing through the two symmetrical heating regions and improving the consistency of the product.

[0099] Optionally, in Figure 3 Based on the graphitization furnace 200 shown, along the circumference of the material channel 211, a structure such as the second electrode 230 and the first electrode 220 within the furnace body 210 can be provided. Figure 5 The insulating component 240 is shown.

[0100] Optionally, in one embodiment, the insulating element 240 may be an inner lining of the furnace body 210, that is, the inner lining of the furnace body 210 may be made of insulating material. The surfaces of the first electrode 220 and the second electrode 230 within the furnace body 210 that are not in the graphitized region may both be covered by the inner lining of the furnace body.

[0101] Alternatively, in another embodiment, the insulating element 240 may also be independent of the furnace lining within the furnace body 210, which is not limited in this application embodiment.

[0102] In this embodiment, an insulating member 240 is provided between the first electrode 220 and the second electrode 230 along the circumferential direction of the material channel 211. On the one hand, this can restrict the material channel 211 so that the material can only pass through the heating area between the first surface 221 and the second surface 231, thereby improving the consistency of the product. On the other hand, it can also reduce the possibility of forming an electric field in the area outside the graphitized region.

[0103] Figure 6 A schematic cross-sectional view of a graphitization furnace 200 provided in another embodiment of this application is shown.

[0104] like Figure 6 As shown, the graphitization furnace 200 includes: a furnace body 210, with a material channel 211; a first electrode 220 extending along a first direction X and passing through the material channel 211; a second electrode 230 spaced apart from the first electrode 220 along the radial direction Y of the material channel 211 and arranged around the material channel, with the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 arranged opposite to each other along the radial direction Y of the material channel 211; and a third electrode 250 spaced apart from the first electrode 220 along the extending direction Z of the material channel 211 and arranged around the material channel 211, with the first electrode 220 and the third electrode 250 having opposite polarities.

[0105] The first electrode 220 and the third electrode 250 have opposite polarities, which means that an electric field can be formed between them. For example, the first electrode 220 can be a positive electrode, and the third electrode 250 a negative electrode. Or, for another example, the first electrode 220 can be a negative electrode, and the third electrode 250 a positive electrode. It should be noted that in this embodiment, since the first electrode 220 and the second electrode 230 have opposite polarities, and the first electrode 220 and the third electrode 250 have opposite polarities, the second electrode 230 and the third electrode 250 have the same polarity regardless of whether the first electrode 220 is positive or negative.

[0106] Optionally, as mentioned above, the second electrode 230 and the first electrode 220 can be set at the same height in the material channel 211. Then, the third electrode 250 and the second electrode 230 can be set at different heights in the material channel. This allows the material to pass through both the heating area formed between the first electrode 220 and the second electrode 230 and the heating area formed between the first electrode 220 and the third electrode 250 when it flows in the furnace body 210, thereby improving the graphitization degree of the material.

[0107] In one embodiment, the second electrode 230 is closer to the inlet 212 of the material channel 211 than the third electrode 250.

[0108] In another embodiment, the second electrode 230 is further away from the inlet 212 of the material channel 211 than the third electrode 250.

[0109] Optionally, such as Figure 6 As shown, the third electrode 250 is provided with a cavity 251 extending along the extension direction Z of the material channel 211, and the cavity 251 forms part of the material channel 211.

[0110] Optionally, such as Figure 6 As shown, the third surface 222 of the first electrode 220 and the fourth surface 252 of the third electrode 250 are disposed opposite each other along the extension direction Z of the material channel 211, and a portion of the material channel 211 is formed between the third surface 222 and the fourth surface 252. Alternatively, it can be understood that the third surface 222 of the first electrode 220 and the fourth surface 252 of the third electrode 250, projected onto a plane perpendicular to the extension direction Z of the material channel 211, at least partially overlap.

[0111] In this embodiment, the first surface 221 of the first electrode 220 and the second surface 231 of the second electrode 230 are arranged opposite each other along the radial direction Y of the material channel 211, and the third surface 222 of the first electrode 220 and the fourth surface 252 of the third electrode 250 are arranged opposite each other along the extension direction Z of the material channel 211, so that the material can be heated between the first surface 221 and the second surface 231 and between the third surface 222 and the fourth surface 252 during the flow process, thereby improving the graphitization degree of the material.

[0112] Optionally, in this embodiment, the third surface 222 and the fourth surface 252 may be parallel to each other. Also optionally, the third surface 222 and the fourth surface 252 may both be perpendicular to the extending direction Z of the material channel 211.

[0113] For descriptions of the third surface 222 and the fourth surface 252, please refer to... Figure 4 The first surface 221 and the second surface 231 are not described in detail here for the sake of simplicity.

[0114] Optionally, in the embodiments of this application, it can be in accordance with Figure 6 The electrode pair arrangement shown has multiple heating zones at different heights in the material channel 211 to improve the graphitization degree of the material. This application embodiment does not limit this.

[0115] Optionally, such as Figure 6 As shown, the third electrode 250 includes an electrode ring 253, which is disposed around the material channel 211, and the third electrode 250 is annular in shape. For example, in Figure 6 In the first electrode 220, the lower surface is the third surface 222 of the first electrode 220, and the upper surface of the electrode ring 253 is the fourth surface 252 of the third electrode 250. The upper surface of the electrode ring 253 is annular in shape.

[0116] In this embodiment, the third electrode 250 includes an electrode ring 253, and the electrode ring 253 is disposed around the material channel 211, such that the heating area between the first electrode 220 and the third electrode 250 surrounds the entire circumference N of the material channel 211 (see [link]). Figure 5 This setting improves the uniformity of heating of materials during the flow process, thereby enhancing product consistency.

[0117] Optionally, such as Figure 6 As shown, the third electrode 250 may also include a connecting post 254, which extends radially Y along the material channel 211 and is inserted into the furnace body 210 to connect with the electrode ring 253. That is, the electrode ring 253 is connected to the power supply outside the furnace body 210 through the connecting post 254.

[0118] Optionally, the electrode ring 253 can be connected to a power source via a plurality of connecting posts 254, which are evenly distributed along the circumferential direction N of the electrode ring 253.

[0119] Optionally, such as Figure 6 As shown, the upper surface of the electrode ring 253 (i.e., the fourth surface 252 of the third electrode 250) can be flush with the upper surface 2541 of the connecting post 254. The relationship between the dimension a of the connecting post 254 in the extension direction Z of the material channel 211 and the dimension b of the electrode ring 253 in the extension direction Z of the material channel 211 can satisfy: b = M * a, where M is the number of connecting posts 254.

[0120] Optionally, the orthographic projection of the third surface 222 onto a plane perpendicular to the extension direction Z of the material channel 211 completely covers the orthographic projection of the fourth surface 252 onto a plane perpendicular to the extension direction Z of the material channel 211. For example, the first electrode 220 is a square cylindrical electrode, and the electrode ring 253 is a square ring electrode. In the first direction X, the size of the first electrode 220 is greater than or equal to the outer ring size of the electrode ring 253. In the second direction P, the size of the first electrode 220 is equal to the outer ring size of the electrode ring 253, and the electrode ring 253 is located directly below the first electrode 220.

[0121] In this embodiment, the orthographic projection of the third surface 222 on the plane perpendicular to the extension direction Z of the material channel 211 completely covers the orthographic projection of the fourth surface 252 on the plane perpendicular to the extension direction Z of the material channel 211. This is beneficial to increase the heating area between the first electrode 220 and the third electrode 250 while maximizing the flow of the material within the third electrode 250.

[0122] Figure 7 The orthographic projection of the third surface 222 onto a plane perpendicular to the extension direction Z of the material channel 211 and the orthographic projection of the fourth surface onto a plane perpendicular to the extension direction Z of the material channel 211 are shown. The projected area of ​​the third surface 222 on this plane is S1, and the area of ​​the portion of the fourth surface 252 projected onto this plane and overlapping with the third surface 222 is S2. Through extensive experimental verification, it has been found that the ratio of S2 to S1 can be 0.2 to 0.5. For example, the ratio of S2 to S1 can be equal to 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0123] In this embodiment, if the ratio of S2 to S1 is less than 0.2, the heating area between the third surface 222 and the fourth surface 252 may be too small, failing to achieve the effect of further heating the material between the first electrode 220 and the third electrode 250. If the ratio of S2 to S1 is greater than 0.5, the cavity 251 in the electrode ring 253 may be too small, insufficient for the material to flow smoothly through the cavity 251. Through a large number of experiments, it has been found that setting the ratio of S2 to S1 to 0.2 to 0.5 is beneficial to balancing the heating effect and the flowability of the material.

[0124] It should be noted that, for a vertical graphitization furnace, if the orthographic projection of the third surface 222 on a plane perpendicular to the extension direction Z of the material channel 211 completely covers the orthographic projection of the fourth surface 252 on a plane perpendicular to the extension direction Z of the material channel 211, then the part of the fourth surface 252 projected onto this plane and overlapping with the third surface 222 is the upper surface of the third electrode 250.

[0125] Optionally, in this embodiment, the ratio of S2 to S1 is 1 / 3.

[0126] In this embodiment, setting the ratio of S2 to S1 to 1 / 3 allows for a balance between the heating effect and the flowability of the material.

[0127] Optionally, the first electrode 220 is a square cylindrical electrode, as shown in... Figure 6 In the second direction P shown, the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 can be 1.2 to 2, wherein the second direction P is perpendicular to the first direction X and perpendicular to the extension direction Z of the material channel. For example, as Figure 7 As shown, in the second direction P, the size of the first electrode 220 is c, and the inner diameter of the electrode ring 253 is d. Through extensive experimental verification, it has been found that the ratio of c to d can be 1.2 to 2, for example, the ratio of c to d is 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, etc.

[0128] Optionally, in other embodiments, the first electrode 220 is a cylindrical electrode, and in the second direction P, the ratio of the size of the first electrode 220 to the inner diameter of the third electrode 250 can be 1.2 to 2.

[0129] In this embodiment, in the second direction P, if the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 is less than 1.2, the heating area between the third surface 222 and the fourth surface 252 may be small, failing to achieve the effect of further heating the material between the first electrode 220 and the third electrode 250. If the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 is greater than 2, the cavity 251 in the electrode ring 253 may be too small, insufficient for the material to flow smoothly through the cavity 251. Through numerous experiments, it has been found that setting the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 to 1.2 to 2 is beneficial for balancing the heating effect and the flowability of the material.

[0130] Optionally, in this embodiment, in the second direction P, the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 is 1.5 to 2. For example, the ratio of c to d is 1.5 to 2.

[0131] In this embodiment, in the second direction, the ratio of the size of the first electrode 220 to the inner diameter of the electrode ring 253 is set to 1.5 to 2, which enables the heating effect and flowability of the material to be balanced.

[0132] Optionally, in embodiments of this application, the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 is 0.2 to 1. For example, as Figure 6 As shown, the distance between the first surface 221 and the second surface 231 is L1, and the distance between the third surface 222 and the fourth surface 252 is L2. Through extensive experimental verification, it has been found that the ratio of L1 to L2 can be 0.2 to 1. For example, the ratio of L1 to L2 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, etc.

[0133] In this embodiment, if the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 is less than 0.2, it may result in an excessively large distance between the third surface 222 and the fourth surface 252, causing the electric field between them to be too weak and failing to achieve the effect of further heating the material between the first electrode 220 and the third electrode 250. If the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 is greater than 1, it may result in... After the material flows through the heating area between the first surface 221 and the second surface 231, it does not have time to be heated in the heating area between the third surface 222 and the fourth surface 252 before flowing out, thus failing to achieve the effect of further heating the material between the first electrode 220 and the third electrode 250. However, through a large number of experiments, it has been found that setting the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 to 0.2 to 1 is beneficial to improving the heating effect of the material between the third surface 222 and the fourth surface 252.

[0134] Optionally, in this embodiment, the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 is 0.5 to 1.

[0135] In this embodiment, the ratio of the distance between the first surface 221 and the second surface 231 to the distance between the third surface 222 and the fourth surface 252 is set to 0.5 to 1, which can improve the heating effect of the material between the third surface 222 and the fourth surface 252, thereby improving the graphitization degree of the material.

[0136] See also Figure 6 The graphitization furnace 200 may further include: a furnace lining 260, which is arranged around the inner wall of the furnace body 210; wherein the first electrode 220 and the second electrode 230 both pass through the furnace lining 260 and are connected to a power source outside the furnace body 210.

[0137] In this embodiment, a furnace lining 260 is provided around the inner wall of the furnace body 210, which can provide heat insulation and heat preservation for the high temperature inside the furnace body 210.

[0138] Alternatively, the furnace lining 260 can also be made of insulating material.

[0139] Optionally, such as Figure 6 As shown, the furnace lining 260 may include an insulation layer 262 and a heat-resistant layer 261, wherein the heat-resistant layer 261 is disposed around the insulation layer 262, and the thermal conductivity of the insulation layer 262 is lower than that of the heat-resistant layer 261.

[0140] Optionally, the insulation layer 262 can be made of a material with large-particle insulation properties, a particle size of 10-30mm, and a thermal conductivity of 0.2-0.5W / mk, which can improve the insulation effect, reduce heat loss, and lower energy consumption. The heat-resistant layer 261 can be made of a material with a temperature resistance of 1450-3000℃, a thermal conductivity of 0.5-1.2W / mk, and good insulation properties, thereby extending the service life of the graphitization furnace.

[0141] Optionally, the heat-resistant layer 261 can be composed, from the outside to the inside, of a steel plate, ceramic fiber products, lightweight refractory bricks / castables, and heavyweight refractory bricks / castables. The insulation layer 262 can be composed of high-temperature resistant lightweight carbon insulation material.

[0142] In this embodiment, the provision of a multi-layer heat-insulating furnace lining can extend the service life of the graphitization furnace 200. In addition, setting the thermal conductivity of the insulation layer 262 to be lower than that of the heat-resistant layer 261 can improve the heat insulation effect while reducing the cost of the graphitization furnace.

[0143] Optionally, in the embodiments of this application, the first electrode 220 is a graphite electrode; and / or, the second electrode 230 is a graphite electrode.

[0144] Alternatively, the third electrode 250 can also be a graphite electrode.

[0145] Optionally, such as Figure 8 As shown, this application embodiment also provides a battery preparation apparatus 300, which may include the graphitization furnace 200 described in the above embodiments, and the graphitization furnace 200 can be used to prepare the negative electrode material of the battery.

[0146] Optionally, the battery in the embodiments of this application may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to this.

[0147] The batteries described in the embodiments of this application are applicable to various battery-using devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0148] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A graphitization furnace, characterized in that, include: The furnace body is equipped with a material passage. A first electrode extends along a first direction and through the material channel, the first direction being perpendicular to the extension direction of the material channel; The second electrode is disposed at a distance from the first electrode and surrounds the material channel; The first electrode and the second electrode have opposite polarities, and at least a portion of the surface of the first electrode is disposed opposite to at least a portion of the surface of the second electrode, forming a part of the material channel between at least a portion of the surface of the first electrode and at least a portion of the surface of the second electrode.

2. The graphitization furnace according to claim 1, characterized in that, The first surface of the first electrode and the second surface of the second electrode are arranged radially opposite each other along the material channel.

3. The graphitization furnace according to claim 2, characterized in that, The first surface and the second surface are parallel to each other, and / or both the first surface and the second surface are parallel to the extension direction of the material channel.

4. The graphitization furnace according to claim 3, characterized in that, The second electrode includes at least one pair of electrode posts extending radially along the material channel, wherein two electrode posts in each pair of electrode posts are respectively disposed on both sides of the first electrode.

5. The graphitization furnace according to claim 4, characterized in that, The two electrode posts in each pair are arranged symmetrically relative to the first electrode.

6. The graphitization furnace according to claim 5, characterized in that, An insulating element is provided between the second electrode and the first electrode inside the furnace body along the circumference of the material channel.

7. The graphitization furnace according to claim 6, characterized in that, The graphitization furnace also includes: The third electrode is disposed at a distance from the first electrode along the extension direction of the material channel, the third electrode is disposed around the material channel, and the polarity of the third electrode is opposite to that of the first electrode.

8. The graphitization furnace according to claim 7, characterized in that, The third surface of the first electrode and the fourth surface of the third electrode are disposed opposite each other along the extending direction of the material channel, and a portion of the material channel is formed between the third surface and the fourth surface.

9. The graphitization furnace according to claim 8, characterized in that, The third surface and the fourth surface are parallel to each other, and / or both the third surface and the fourth surface are perpendicular to the extension direction of the material channel.

10. The graphitization furnace according to claim 9, characterized in that, The third electrode includes an electrode ring arranged around the material channel, and the fourth surface is annular in shape.

11. The graphitization furnace according to claim 10, characterized in that, The orthographic projection of the third surface onto a plane perpendicular to the extension direction of the material channel completely covers the orthographic projection of the fourth surface onto that plane.

12. The graphitization furnace according to claim 11, characterized in that, The projected area of ​​the third surface on a plane perpendicular to the extension direction of the material channel is S1, and the area of ​​the portion of the fourth surface projected onto the plane and overlapping with the third surface is S2, wherein the ratio of S2 to S1 is 0.2 to 0.

5.

13. The graphitization furnace according to claim 12, characterized in that, The ratio of S2 to S1 is 1 / 3.

14. The graphitization furnace according to claim 13, characterized in that, The first electrode is a square columnar electrode. In the second direction, the ratio of the size of the first electrode to the inner diameter of the electrode ring is 1.2 to 2. The second direction is perpendicular to the first direction and perpendicular to the extension direction of the material channel.

15. The graphitization furnace according to claim 14, characterized in that, In the second direction, the ratio of the size of the first electrode to the inner diameter of the electrode ring is 1.5 to 2.

16. The graphitization furnace according to claim 15, characterized in that, The ratio of the distance between the first surface and the second surface to the distance between the third surface and the fourth surface is 0.2 to 1.

17. The graphitization furnace according to claim 16, characterized in that, The ratio of the distance between the first surface and the second surface to the distance between the third surface and the fourth surface is 0.5 to 1.

18. The graphitization furnace according to claim 17, characterized in that, The second electrode is closer to the inlet of the material channel than the third electrode.

19. The graphitization furnace according to claim 1, characterized in that, The first surface of the first electrode and the second surface of the second electrode are disposed opposite to each other along the extension direction of the material channel.

20. The graphitization furnace according to claim 19, characterized in that, The graphitization furnace also includes: The furnace lining is arranged around the inner wall of the furnace body; Both the first electrode and the second electrode pass through the furnace lining and are connected to a power source outside the furnace.

21. The graphitization furnace according to claim 20, characterized in that, The furnace lining includes: The insulation layer and the heat-resistant layer are provided around the insulation layer, and the thermal conductivity of the insulation layer is lower than that of the heat-resistant layer.

22. The graphitization furnace according to claim 21, characterized in that, The first electrode is a graphite electrode, and / or the second electrode is a graphite electrode.

23. The graphitization furnace according to claim 22, characterized in that, The material channel extends in a vertical direction.

24. A battery manufacturing apparatus, characterized in that, The method includes a graphitization furnace as described in any one of claims 1 to 23, the graphitization furnace being used to prepare the negative electrode material of the battery.

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