Graphitization furnace including widened cross-section

Abstract

In a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet and a product outlet. The graphitization furnace further includes a channel 100 connecting the raw material inlet and the product outlet, the channel 100 including an upstream section 110 closer to the raw material inlet and a downstream section 120 closer to the product outlet. The upstream section 110 has a first cross-section closer to the raw material inlet and a second cross-section closer to the product outlet, and the downstream section 120 has a third cross-section closer to the raw material inlet and a fourth cross-section closer to the product outlet, where the second cross-sectional section is larger than the first cross-section, and the fourth cross-section is larger than the second and third cross-sections.

Description

Technical Field

[0001] The present invention relates to the field of graphitization furnaces. More specifically, the present invention relates to a graphitization furnace including an expanded cross-section.

Background Art

[0002] The most commonly commercially used anode material in lithium-ion batteries is graphite. Graphite can be lithiated to the state of LiC6, which correlates with a theoretical maximum capacity of 372 mAh / g.

[0003] Artificial graphite can be produced by heating a carbonaceous starting material (such as coke and / or pitch, etc.) to a temperature of about 3000 °C under the exclusion of oxygen. The heating can be carried out in a batch furnace or a continuous furnace. In a continuous furnace, the carbonaceous material is typically conveyed along a heated channel and converted to graphite while being conveyed.

[0004] The process of continuous graphitization can be advantageous because it can produce graphite more efficiently than a batch process and enable production on an industrial scale. However, the inventor has found that some carbonaceous materials (especially carbonaceous materials in powder form) may tend to cake in a continuous furnace. Caking can lead to a non-uniform temperature distribution, and it can result in a reduction in product quality and consistency. Also, it can result in a reduction in process efficiency and higher production costs due to interruptions in the continuous process while eliminating channel blockages induced by caking and the need to reprocess some products that were not fully graphitized due to caking.

[0005] To address the above problems, the inventors have developed a graphitization furnace.

Summary of the Invention

[0006] In a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet and a product outlet. The graphitization furnace includes a channel connecting the raw material inlet and the product outlet, the channel including an upstream section and a downstream section. The upstream section has a first cross section closer to the raw material inlet and a second cross section closer to the product outlet, and the downstream section has a third cross section closer to the raw material inlet and a fourth cross section closer to the product outlet. The second cross section is larger than the first cross section, and the fourth cross section is larger than the second and third cross sections.

[0007] In some embodiments, the upstream and downstream sections may be spaced apart or adjacent to each other.

[0008] In some embodiments, an edge-shaped or arch-shaped transition section may be provided between the upstream section and the downstream section.

[0009] In some embodiments, the graphitization furnace can be a vertical graphitization furnace. In some embodiments, the graphitization furnace can be a vertical graphitization furnace, and the downstream section can be located in the lower third, lower quarter, lower fifth, or lower sixth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity. In some embodiments, the upstream section can be located in the lower half, lower third, lower quarter, or lower fifth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity.

[0010] In some embodiments, the graphitization furnace can be a vertical graphitization furnace, and the downstream section can be located in the lower third, lower quarter, lower fifth, or lower sixth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, and the upstream section can be located in the lower half, lower third, lower quarter, or lower fifth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity.

[0011] In some embodiments, the channel may include a heating zone, a high-temperature reaction zone, and a cooling zone.

[0012] In some embodiments, the downstream section can be located in a high-temperature reaction zone and / or a cooling zone, and in particular, in a cooling zone.

[0013] In some embodiments, the upstream section may have a first length L1, the downstream section may have a second length L2, more specifically, the upstream and downstream sections may be adjacent, the upstream and downstream sections may have a combined length L3, and the ratio L2 / L3 may be less than 0.5, more specifically less than 0.3, and in particular less than 0.2.

[0014] In some embodiments, the L2 / L3 ratio can be between about 0.03 and about 0.5, more specifically between 0.05 and about 0.3, and in particular between about 0.1 and about 0.2.

[0015] In some embodiments, the channel may have a first inner diameter D1, a second inner diameter D2, a third inner diameter D3, and a fourth inner diameter D4 in the planes of the first, second, third, and fourth cross-sections, respectively, such that the inner diameters satisfy the requirement (D2-D1) / L1 < (D4-D3) / L2.

[0016] In some embodiments, the channel may have a first angle α1 defined such that criterion α1 = arctan((D2-D1) / (2×L1)) and a second angle α2 defined such that criterion α2 = arctan((D4-D3) / (2×L2)), where α1 < α2.

[0017] In some embodiments, the first angle α1 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0018] In some embodiments, the first angle α1 can be between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0019] In some embodiments, the first angle α1 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and it may be particularly advantageous that the first angle α1 can be between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0020] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0021] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically, between about 0.2° and about 2°, and particularly between about 0.3° and about 1.5°.

[0022] In some embodiments, the second angle α2 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0023] In some embodiments, the second angle α2 can be between about 0.1° and about 45°, more specifically, between about 0.2° and 20°, and particularly between about 0.3° and about 10°.

[0024] In some embodiments, the second angle α2 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°. Particularly, it can be particularly advantageous that the second angle α2 can be between about 0.1° and about 20°, more specifically, between about 0.2° and 10°, and particularly between about 0.3° and about 5°.

[0025] In some embodiments, the second angle α2 can be between about 0.1° and about 5°, more specifically, between about 0.1° and about 2°, and particularly between about 0.1° and about 1.5°.

[0026] In some embodiments, the second angle α2 can be between about 0.1° and about 5°, more specifically, between about 0.2° and about 2°, and particularly between about 0.3° and about 1.5°.

[0027] In some embodiments, the first angle α1 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and the second angle α2 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0028] InInIn some embodiments, the first angle α1 can be between about 0.1° and about 45°, more specifically, between about 0.2° and 20°, and particularly between about 0.3° and about 10°. The second angle α2 can be between about 0.1° and about 45°, more specifically, about 0.2°, and particularly between about 0.3° and about 10°.

[0029] In some embodiments, the first angle α1 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and particularly, the first angle α1 can be between about 0.1° and about 20°, more specifically, between about 0.2° and 10°, and particularly between about 0.3° and about 5°. The second angle α2 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and particularly, the second angle α2 can be between about 0.1° and about 20°, more specifically, between about 0.2° and 10°, and particularly between about 0.3° and about 5°. This can be particularly advantageous.

[0030] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0031] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0032] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0033] In some embodiments, the second cross-section is a third cross-section.

[0034] In some embodiments, the graphitization furnace can be a continuous graphitization furnace or a semi-batch graphitization furnace, and in particular, it can be a continuous graphitization furnace.

[0035] In some embodiments, the graphitization furnace can be configured such that the material flow within the graphitization furnace is gravity-assisted.

[0036] In some embodiments, the upstream section and / or downstream section may contain or be composed of graphite.

[0037] In some embodiments, the cross-section of the upstream or downstream section (a cross-section perpendicular to the central channel axis) can be circular, elliptical, or polygonal, more specifically, octagonal, hexagonal, rectangular, square, or elliptical, and in particular, rectangular or elliptical.

[0038] In some embodiments where the cross-section of the upstream or downstream section is polygonal, the corners of the polygon are rounded.

[0039] In some embodiments, the graphitization furnace may include a stirrer that extends at least partially into the channel, and more specifically, into the downstream section.

[0040] In a second embodiment, the disclosure relates to a method of using a graphitization furnace according to any of the preceding claims to prepare graphite from a carbonaceous material. [Brief explanation of the drawing]

[0041] [Figure 1] This figure shows a cross-section of Channel 100, including a straight upstream section 110 and a straight downstream section 120. [Figure 2] This figure shows a cross-section of the channel 100, which includes a straight upstream section 110 and a curved downstream section 120. [Figure 3] This is an isometric view of Channel 100, including the straight upstream section 110, the straight downstream section 120, and the rectangular perimeter. [Modes for carrying out the invention]

[0042] The following provides a detailed description of this disclosure. Terms or phrases used in the description and embodiments of this disclosure are not to be constrained to have only common language or dictionary meanings, but rather to have their ordinary technical meanings as established in the relevant art, unless specifically defined otherwise in the following description. The detailed description will refer to specific embodiments to better illustrate this disclosure, but it is understood that the disclosure presented is not limited to these specific embodiments.

[0043] As described above, artificial graphite can be produced by heating carbonaceous starting materials (e.g., coke and / or pitch) to a temperature of approximately 3000°C under the exclusion of oxygen. The starting materials typically contain amorphous carbon, which is converted into graphite due to the heat. An important property of graphite is its degree of crystallinity. A higher degree of crystallinity can result in a higher maximum specific capacity, for example, when used in batteries.

[0044] The term "graphite" is well known and has a common meaning in the art. More specifically, the term "graphite" can refer to a material containing hexagonal crystalline carbon. Alternatively or additionally, the term "graphite" can refer to a material containing at least about 60%, more specifically at least about 80%, and in particular at least about 83%, hexagonal crystalline carbon. Alternatively or additionally, the term "graphite" can refer to a material having a degree of graphitization of at least about 46%, more specifically 69%, and even more specifically at least about 80%, and in particular at least about 83%.

[0045] The degree of crystallinity of graphite can be described through its degree of graphitization, which can be measured by X-ray diffraction (XRD). The crystalline carbon in graphite forms a multi-layered honeycomb lattice. The distance between the multi-layered honeycomb lattices is given by the parameter "interplane distance d". 002This is explained by . XRD is the inter-face distance d between multiple grids. 001 It can be used to measure the interplane distance d of 0.3440 nm. 002 This corresponds to the interplane distance in a randomly layered graphite structure, and an interplane distance of 0.3354 nm corresponds to the interplane distance in a perfect graphite crystal.

[0046] The interplane distance can be used to calculate the degree of graphitization using the following formula.

[0047] Graphitization degree = (0.3440 nm - d 002 ) / (0.3440nm-0.3354nm)

[0048] A higher degree of graphitization can accommodate a higher maximum discharge capacity.

[0049] The heat treatment of carbonaceous materials can be carried out in a continuous furnace (i.e., a furnace configured for the continuous or semi-continuous production of graphite). For example, the carbonaceous raw material can be transported along a channel 100 between a raw material inlet and a product outlet while being heated. The carbonaceous raw material can be in any form, for example, in powder form or granular form, and more specifically, in powder form.

[0050] However, it has been found that carbonaceous material may caking in sections of channel 100. In particular, caking is likely to occur in sections closer to the product outlet. Channel 100 can be positioned vertically between a material inlet at the top and an outlet at the bottom. As a result, the carbonaceous material can form a material column, and the carbonaceous material at the bottom of the material column (for example, near the product outlet) is compressed by the carbonaceous material positioned above it. This compression can significantly increase the material's tendency to caking.

[0051] Furthermore, this caking may result in reduced fluidity of the carbonaceous material, which can lead to inhibited material flow. In particular, reduced fluidity can result in obstructed discharge of the carbonaceous material from the product outlet. Additionally, caking and / or reduced fluidity can lead to heterogeneity in the transported carbonaceous material. For example, caking and / or reduced fluidity can lead to a heterogeneous temperature distribution in the carbonaceous material placed in the graphitization furnace. These heterogeneities can then result in reduced product quality (e.g., reduced or heterogeneous graphitization). Moreover, caking may also lead to the product discharged from the graphitization furnace containing agglutinations, which can reduce product quality or require post-treatment to break down the agglutinations.

[0052] It has been found that the transport of easily caking carbonaceous materials can be improved by providing channel sections with increasing diameter in the material transport direction, and additional channel sections with further increasing diameter. Products obtained from such furnaces can be endowed with excellent product quality, making them particularly suitable for use as anode materials (especially anode materials for lithium batteries).

[0053] Accordingly, in a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet and a product outlet. Furthermore, the graphitization furnace includes a channel 100 connecting the raw material inlet and the product outlet, the channel 100 including an upstream section 110 and a downstream section 120. The upstream section 110 has a first cross section closer to the raw material inlet and a second cross section closer to the product outlet, and the downstream section 120 has a third cross section closer to the raw material inlet and a fourth cross section closer to the product outlet, where the second cross section is larger than the first cross section, and the fourth cross section is larger than the second and third cross sections.

[0054] The terms upstream and downstream as used herein have their typical meanings in the art, with upstream referring to the section closer to the raw material inlet and downstream referring to the section closer to the product outlet.

[0055] Figure 1 shows an example of a channel 100 including a central channel axis 130. The central channel axis 130 can correspond to the material flow direction F. As depicted in Figure 1, the upstream section 110 can have a first length L1 parallel to the central channel axis 130. Alternatively, the first length L1 can be the length between a first cross section and a second cross section parallel to the central channel axis 130. The downstream section 120 can have a second length L2 parallel to the central channel axis 130. Length L2 can be measured between a third cross section and a fourth cross section.

[0056] Furthermore, the upstream section 110 and the downstream section 120 may have a total third length L3 parallel to the central channel axis 130. Alternatively, length L3 may be the length between the first and fourth cross-sections parallel to the central channel axis 130.

[0057] The method for measuring L1, L2, and L3 is not particularly limited. For example, the first length can be determined by measuring the length of the central channel axis 130 between the first cross section and the second cross section. Alternatively, the first length L1 can be determined by measuring the distance between the geometric center of the first cross section and the geometric center of the second cross section. Similarly, the second length L2 can be determined by measuring the distance between the geometric center of the third cross section and the geometric center of the fourth cross section, and the third length L3 can be determined by measuring the distance between the geometric center of the first cross section and the geometric center of the fourth cross section. Alternatively, L1 and L2 can be determined based on the cross section of the channel. In this case, the distance from the intersections of the central channel axis 130 and the third and fourth cross sections represents L2, and the distance from the intersections of the central channel axis 130 and the first and second cross sections represents L1. Similarly, the third length L3 can be the distance from the intersections of the central channel axis 130 with the first and fourth cross-sections.

[0058] Furthermore, the central channel axis 130 is not necessarily straight. For example, if the channel 100 is curved, the central channel axis 130 can also be curved. In this case, L1 and L2 can be measured by determining the geometric centers of multiple cross-sections along the channel 100, and by summing the individual distances between the geometric centers located in the upstream and downstream sections, respectively.

[0059] Furthermore, as shown in Figure 1, the channel 100 may have a first inner diameter D1 in the plane of the first cross-section. Thus, as shown in Figure 1, the channel 100 may have a second inner diameter D2, a third inner diameter D3, and a fourth inner diameter D4 in the planes of the second, third, and fourth cross-sections, respectively. In some embodiments, the cross-section of the upstream section 110 or the downstream section 120 (the cross-section perpendicular to the central channel axis 130) may be elliptical or polygonal, more specifically, octagonal, hexagonal, rectangular, square, or elliptical, and in particular, rectangular or elliptical. With respect to a circular cross-section, diameters D1 to D4 are the respective inner diameters in the corresponding planes of the first to fourth cross-sections. Those skilled in the art will know how to determine the diameter, but in case of doubt, the diameter refers to the maximum diameter in the plane. For example, in the case of a square cross-section, the lengths of the diagonals in the plane of the cross-section can be considered as the respective diameters of the square.

[0060] In some embodiments, the cross-section of the upstream or downstream section is polygonal, and the corners of the polygon are rounded.

[0061] In a channel 100 having a rectangular or square cross-section (a cross-section perpendicular to the central channel axis 130), not all wall sections of the channel 100 need to be angled radially outward (in the material flow direction F and with respect to the central channel axis 130) in order to achieve a widened cross-section. For example, as shown in Figure 3, the channel 100 may include two wall sections aligned parallel to the central channel axis 130 and two wall sections positioned diagonally to the central channel axis 130.

[0062] Here and elsewhere, the term “wall section” refers to a portion of the wall of channel 100, more specifically, a portion of the wall having a length of at least 5 cm, and more specifically, at least 10 cm. In particular, the term “wall section” can refer to a portion of the wall having a length of at least 5 cm, in particular at least 10 cm, and a width of at least 10 cm. The width and length can also be measured along a curved wall segment (along a curved surface). For example, in channel 100 having a square cross-section, a wall section can be one side of the downstream section 120.

[0063] As described above, the risk of caking may be highest in the section located closest to the product outlet (for example, in the downstream section 120). In particular, the graphitization furnace can be a vertical type, where the carbonaceous material forms a material column. As previously described, the temperature of the carbonaceous material may be lowest and the compressive force on the material column may be highest in the section closest to the product outlet. Furthermore, the conveying means may be located near the product outlet, which may introduce further force to the carbonaceous material, which may further increase the risk of caking. Therefore, the downstream section 120 may be located at a larger angle (or a larger radially outward inclination) with respect to the central channel axis 130 compared to the upstream section 110. Thus, in some embodiments, (D4-D3) / L2 may be larger than (D2-D1) / L1.

[0064] Furthermore, the geometric shape of the channel 100 can also be determined by the angle between the central channel axis 130 and the inner side of the upstream section 110 or the downstream section 120. Thus, the first angle α1 can be defined as α1 = arctan((D2-D1) / (2×L1)), and the second angle α2 can be defined as α2 = arctan((D4-D3) / (2×L2)). In some embodiments, α2 can be greater than α1. The first angle α1 and the second angle α2 are shown in Figures 1 and 2.

[0065] In some embodiments, the first angle α1 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0066] In some embodiments, the first angle α1 can be between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0067] In some embodiments, the first angle α1 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and it may be particularly advantageous that the first angle α1 can be between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0068] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0069] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0070] In some embodiments, the second angle α2 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0071] In some embodiments, the second angle α2 can be between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0072] In some embodiments, the second angle α2 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and it may be particularly advantageous that the second angle α2 can be between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0073] In some embodiments, the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0074] In some embodiments, the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0075] In some embodiments, the first angle α1 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and the second angle α2 can be less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0076] In some embodiments, the first angle α1 can be between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°, and the second angle α2 can be between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0077] In some embodiments, it may be particularly advantageous that the first angle α1 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the first angle α1 can be between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°; and the second angle α2 can be less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the second angle α2 can be between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0078] As described above, it has been found that the transport of carbonaceous materials prone to caking can be improved by providing channel sections with increasing diameter in the material transport direction, and additional channel sections with further increasing diameter. However, increasing the diameter also results in increased space requirements for the graphitization furnace. After vigorous research, it has been found that, in general, sufficient material flow can still be ensured when angles α1 and α2 are below 10° but above 0.1°. In particular, when angles α1 and α2 are between approximately 0.1° and 5°, material flow can still be sufficient, while simultaneously resulting in minimum space requirements.

[0079] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0080] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0081] In some embodiments, the first angle α1 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°, and the second angle α2 can be between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0082] In some embodiments, the channel 100 may include a heating zone, a high-temperature reaction zone, and a cooling zone. The heating zone may be characterized by an increase in the temperature of the carbonaceous material in the flow direction when the graphitization furnace is used. The high-temperature reaction zone may be characterized by a carbonaceous material having a temperature of at least 80% of the maximum temperature achievable in the graphitization furnace. The cooling zone may be characterized by a decrease in the temperature of the carbonaceous material in the flow direction when the graphitization furnace is used. The downstream section 120 may be located in the high-temperature reaction zone and / or the cooling zone, and in particular, in the cooling zone. As described above, the carbonaceous material may be prone to caking, in particular where the pressure on the carbonaceous material is highest. Since the cooling zone is typically located at the lowest position in a vertical graphitization oven, increasing the diameter of the downstream section 120 may be particularly advantageous in the cooling zone to prevent caking.

[0083] In some embodiments, the graphitization furnace can be a vertical graphitization furnace. In some embodiments, the graphitization furnace can be a vertical graphitization furnace, and the downstream section can be located in the lower third, lower quarter, lower fifth, or lower sixth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity. In some embodiments, the upstream section can be located in the lower half, lower third, lower quarter, or lower fifth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity.

[0084] In some embodiments, the graphitization furnace can be a vertical graphitization furnace, and the downstream section can be located in the lower third, lower quarter, lower fifth, or lower sixth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, and the upstream section can be located in the lower half, lower third, lower quarter, or lower fifth of the channel, more specifically in the lower fifth or lower sixth of the channel, in particular in the lower fifth of the channel, where the lower part is closer to the Earth's center of gravity. Thus, the widening of the channel 100 can be limited to its lower end.

[0085] Furthermore, in some embodiments, the L2 / L3 ratio can be less than 0.5, more specifically less than 0.3, and in particular less than 0.2. Additionally or alternatively, the L2 / L3 ratio can be between about 0.03 and about 0.5, more specifically between 0.05 and about 0.3, and in particular between about 0.1 and about 0.2. Thus, the length of the downstream section 120 can be significantly shorter compared to the length of the upstream section 110. A significant widening of the downstream section 120 can improve fluidity, but the increased diameter can generally result in increased space requirements for the graphitization furnace with respect to a longer downstream section 120.

[0086] In some embodiments, the cross-sections (coplanar with the central channel axis 130) of the wall sections of the upstream section 110 and / or the downstream section 120 can be straight or curved, and in particular can be straight. In Figure 2, the upstream section 110 is depicted as including two straight wall sections, and the downstream section 120 is depicted as including two curved cross-sections. The two curved cross-sections shown in Figure 2 are concave, but they can also be convex or exhibit irregular curvature.

[0087] In some embodiments, the upstream and downstream sections are spaced apart or adjacent, and in particular, adjacent. In some embodiments, the second cross section is a third cross section. Thus, the downstream section 120 and the upstream section 110 can be directly connected.

[0088] In some embodiments, an edge-shaped or arch-shaped transition section may be provided between the upstream section 110 and the downstream section 120. Such a transition section may be a (abrupt or gradual) change in the cross-sectional diameter from the upstream section 110 to the downstream section 120 and may be provided for a variety of purposes, such as structural needs or to reduce the possibility of material agglomeration at the joint between the upstream section 110 and the downstream section 120. The structure of the transition section is not particularly limited and may be as simple as an edge or curved widening of the channel.

[0089] Furthermore, the size of the cross-section does not have to decrease between the first and second cross-sections, and / or between the third and fourth cross-sections. Therefore, the upstream and / or downstream sections do not have to be tubular, nor do they have to be tapered in the material flow direction F. In some embodiments, the cross-section may increase continuously between the first and second cross-sections, and / or between the third and fourth cross-sections.

[0090] In some embodiments, the graphitization furnace can be a continuous graphitization furnace or a semi-batch graphitization furnace, and in particular, it can be a continuous graphitization furnace. In some embodiments, the material flow in the graphitization furnace (in particular a vertical graphitization furnace) can be gravity-assisted. Although the material flow can be gravity-assisted, the graphitization furnace (in particular channel 100) can include conveying means to control, for example, the rate of material flow and / or discharge from the product outlet.

[0091] The graphitization furnace is configured to withstand temperatures of at least 3000°C inside the channel, at least partially. More specifically, the graphitization furnace can be configured to withstand temperatures of up to 3500°C inside the channel, at least partially.

[0092] In some embodiments, the upstream section 110 and / or the downstream section 120 may contain or be composed of graphite. Graphite can withstand temperatures greater than 3000°C and exhibit good mechanical properties. Furthermore, graphite can exhibit high thermal conductivity, and therefore, the channel 100 containing or composed of graphite may exhibit high thermal conductivity. For example, the channel 100 may be heated by an external heating element, which can conduct heat to the carbonaceous material disposed therein. The heating element may be disposed around or adjacent to the outer perimeter of the channel 100. In particular, the heating element may be disposed around or adjacent to the heating zone and / or high-temperature reaction zone.

[0093] Additionally, graphite can be used as a heating element. For example, an electric current can be applied to a section of channel 100 containing or composed of graphite. The electric current (or electrical energy) can then be converted into thermal energy. Thus, channel 100 itself can heat the carbonaceous material disposed within it. Alternatively, graphite can be used as an electrode to apply an electric current to the carbonaceous material. Therefore, in some embodiments, at least a portion of channel 100 containing or composed of graphite can be a heating element or an electrode.

[0094] In some embodiments, the channel 100 may contain carbon fiber reinforced carbon (CFRC), more specifically, the channel 100 may contain at least about 90% by weight of CFRC relative to the total weight of the channel 100, and in particular, the carbonaceous substrate may contain at least about 95% by weight of CFRC. CFRC can exhibit improved mechanical properties compared to other carbonaceous materials. Furthermore, CRFC is also resistant to high temperatures. The term "CFRC" is well known and has its common meaning in the art. More specifically, the term "CFRC" may refer to a composite material containing carbon fibers in a carbon matrix. In particular, the term "CFRC" may refer to a composite material composed of carbon fibers in a carbon matrix. Also, CFRC can be used as a heating element or as an electrode for applying an electric current to a carbonaceous material. Therefore, in some embodiments, at least a portion of the channel 100 containing or composed of CFRC may be a heating element or an electrode.

[0095] In some embodiments, the graphitization furnace may include a stirrer that extends at least partially into the channel 100, and more specifically, into the downstream section 120. The stirrer may assist in preventing caking of carbonaceous carbon and / or assist in discharging material from the product outlet. The stirrer may include a plurality of mixing paddles. In some embodiments, the stirrer may include a first mixing paddle located in the downstream section and a second mixing paddle located in the upstream section, wherein the first diameter of the first mixing paddle is larger than the second diameter of the second mixing paddle.

[0096] In a second embodiment, the disclosure relates to a method of using a graphitization furnace according to any prior embodiment to prepare graphite from carbonaceous raw materials.

[0097] In some embodiments, the method can produce graphite having a degree of graphitization of at least about 46%, more specifically 69%, even more specifically at least about 80%, and in particular at least about 83%.

[0098] In some embodiments, this method makes it possible to produce graphite suitable for use as an anode material (particularly as an anode material for lithium batteries).

[0099] In some embodiments, the method further includes the step of using graphite produced from operating a graphitization furnace (continuously) to produce an anode for a lithium battery.

[0100] Although the present invention is defined in the appended claims, it should be understood that the present invention may also be defined (alternatively) according to the following embodiments.

[0101] 1. A graphitization furnace, and the graphitization furnace is, The raw material inlet and the product outlet, It includes a channel (100) connecting the raw material inlet and the product outlet, The channel (100) includes an upstream section (110) and a downstream section (120). The upstream section (110) has a first cross-section closer to the raw material inlet and a second cross-section closer to the product outlet. The downstream section (120) has a third cross-section closer to the raw material inlet and a fourth cross-section closer to the product outlet. A graphitization furnace in which the second cross-sectional section is larger than the first cross-section, and the fourth cross-section is larger than the second and third cross-sections.

[0102] 2. The graphitization furnace according to Embodiment 1, wherein the upstream section (110) and the downstream section (120) are spaced apart or adjacent, and in particular adjacent.

[0103] 3. A graphitization furnace according to any prior embodiment, wherein an edge-shaped or arch-shaped transition section is provided between the upstream section (110) and the downstream section (120).

[0104] 4. The graphitizing furnace is a vertical graphitizing furnace, as described in any prior embodiment.

[0105] 5. The graphitizing furnace is a vertical graphitizing furnace, wherein the downstream section (120) is located in the lower third, lower quarter, lower fifth, or lower sixth of the channel (100), more specifically, in the lower fifth or lower sixth of the channel (100), and in particular in the lower fifth of the channel (100), where the lower part is closer to the Earth's center of gravity, as described in any prior embodiment of the graphitizing furnace.

[0106] 6. The graphitizing furnace according to any prior embodiment, wherein the upstream section (110) is located in the lower half, lower third, lower quarter, or lower fifth of the channel (100), more specifically in the lower fifth or lower sixth of the channel (100), and in particular in the lower fifth of the channel (100), where the lower part is closer to the Earth's center of gravity.

[0107] 7. The graphitizing furnace is a vertical graphitizing furnace, the downstream section (120) is located in the lower third, lower quarter, lower fifth, or lower sixth of the channel (100), more specifically in the lower fifth or lower sixth of the channel (100), in particular in the lower fifth of the channel (100), and the upstream section (110) is located in the lower half, lower third, lower quarter, or lower fifth of the channel (100), more specifically in the lower fifth or lower sixth of the channel (100), in particular in the lower fifth of the channel (100), where the lower part is closer to the Earth's center of gravity, as described in any prior embodiment of the graphitizing furnace.

[0108] 8. The graphitization furnace according to any prior embodiment, wherein the channel (100) includes a heating zone, a high-temperature reaction zone, and a cooling zone.

[0109] 9. The graphitization furnace according to Embodiment 8, wherein the downstream section (120) is located in a high-temperature reaction zone and / or a cooling zone, and in particular is located in a cooling zone.

[0110] 10. A graphitizing furnace according to any prior embodiment, wherein the upstream section (110) has a first length L1, and the downstream section (120) has a second length L2, more specifically the upstream section (110) and the downstream section (120) are adjacent, and the upstream section (110) and the downstream section (120) have a combined length L3, and the ratio L2 / L3 is less than 0.5, more specifically less than 0.3, and in particular less than 0.2.

[0111] 11. The graphitization furnace according to Embodiment 10, wherein the L2 / L3 ratio is between approximately 0.03 and approximately 0.5, more specifically between 0.05 and approximately 0.3, and in particular between approximately 0.1 and approximately 0.2.

[0112] 12. The graphitizing furnace according to Embodiment 10 or 11, wherein the channel (100) has a first inner diameter D1, a second inner diameter D2, a third inner diameter D3, and a fourth inner diameter D4 in the plane of the first, second, third, and fourth cross-sections, respectively, and the inner diameters satisfy the requirement (D2-D1) / L1 < (D4-D3) / L2.

[0113] 13. The graphitizing furnace is a continuous graphitizing furnace or a semi-batch graphitizing furnace, and in particular is a continuous graphitizing furnace, as described in any prior embodiment.

[0114] 14. The graphitization furnace according to any prior embodiment, wherein the graphitization furnace is configured such that the material flow within the graphitization furnace is gravity-assisted.

[0115] 15. A graphitization furnace according to any one of embodiments 12 to 14, wherein the channel (100) has a first angle α1 determined to satisfy the criterion α1 = arctan((D2-D1) / (2×L1)) and a second angle α2 determined to satisfy the criterion α2 = arctan((D4-D3) / (2×L2)), and α1 < α2.

[0116] 16. The graphitization furnace according to Embodiment 15, wherein the first angle α1 is less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0117] 17. The graphitization furnace according to Embodiment 15 or 16, wherein the first angle α1 is between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0118] 18. A graphitization furnace according to any one of embodiments 15 to 17, wherein the first angle α1 is less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the first angle α1 is between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0119] 19. A graphitization furnace according to any one of embodiments 15 to 18, wherein the first angle α1 is between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0120] 20. A graphitization furnace according to any one of embodiments 15 to 19, wherein the first angle α1 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0121] 21. A graphitization furnace according to any one of embodiments 15 to 20, wherein the second angle α2 is less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0122] 22. A graphitization furnace according to any one of embodiments 15 to 21, wherein the second angle α2 is between about 0.1° and about 45°, more specifically between about 0.2° and 20°, and in particular between about 0.3° and about 10°.

[0123] 23. A graphitization furnace according to any one of embodiments 15 to 22, wherein the second angle α2 is less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the second angle α2 is between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0124] 24. A graphitization furnace according to any one of embodiments 15 to 23, wherein the second angle α2 is between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and in particular between about 0.1° and about 1.5°.

[0125] 25. A graphitization furnace according to any one of embodiments 15 to 24, wherein the second angle α2 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, and in particular between about 0.3° and about 1.5°.

[0126] 26. The graphitization furnace according to Embodiment 25, wherein the first angle α1 is less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and the second angle α2 is less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°.

[0127] 27. A graphitization furnace according to Embodiment 25 or 26, wherein the first angle α1 is between about 0.1° and about 45°, more specifically between about 0.2° and 20°, in particular between about 0.3° and about 10°, and the second angle α2 is between about 0.1° and about 45°, more specifically between about 0.2° and 20°, in particular between about 0.3° and about 10°.

[0128] 28. A graphitization furnace according to any one of embodiments 25 to 27, wherein the first angle α1 is less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the first angle α1 is between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°, and the second angle α2 is less than 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the second angle α2 is between about 0.1° and about 20°, more specifically between about 0.2° and 10°, and in particular between about 0.3° and about 5°.

[0129] 29. A graphitization furnace according to any one of embodiments 25 to 28, wherein the first angle α1 is between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, in particular between about 0.1° and about 1.5°, and the second angle α2 is between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, in particular between about 0.1° and about 1.5°.

[0130] 30. A graphitization furnace according to any one of embodiments 25 to 29, wherein the first angle α1 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, in particular between about 0.3° and about 1.5°, and the second angle α2 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, in particular between about 0.3° and about 1.5°.

[0131] 31. A graphitization furnace according to any one of embodiments 25 to 30, wherein the first angle α1 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, in particular between about 0.3° and about 1.5°, and the second angle α2 is between about 0.1° and about 5°, more specifically between about 0.2° and about 2°, in particular between about 0.3° and about 1.5°.

[0132] 32. A graphitization furnace according to any prior embodiment, wherein the second cross-section is the third cross-section.

[0133] 33. A graphitizing furnace according to any prior embodiment, wherein the upstream section (110) and / or downstream section (120) contain or consist of graphite.

[0134] 34. The graphitizing furnace according to any prior embodiment, wherein the cross-section of the upstream section (110) or the downstream section (120) perpendicular to the central channel (100) axis is elliptical or polygonal, more specifically octagonal, hexagonal, rectangular, square, or elliptical, and in particular rectangular or elliptical.

[0135] 35. The graphitizing furnace according to any prior embodiment, wherein the graphitizing furnace includes a stirrer, the stirrer extending at least partially into the channel (100) and more specifically into the downstream section (120).

[0136] 36. A method for preparing graphite from a carbonaceous material using a graphitization furnace described in any prior embodiment.

Claims

1. It is a graphitization furnace, The raw material inlet and the product outlet, It includes a channel (100) connecting the raw material inlet and the product outlet, The channel (100) includes an upstream section (110) and a downstream section (120), The upstream section (110) has a first cross-section near the raw material inlet and a second cross-section near the product outlet. The downstream section (120) has a third cross-section near the raw material inlet and a fourth cross-section near the product outlet. A graphitization furnace in which the second cross-section is larger than the first cross-section, and the fourth cross-section is larger than the second and third cross-sections.

2. The graphitization furnace according to claim 1, wherein the upstream section (110) and the downstream section (120) are spaced apart or adjacent to each other, and in particular adjacent to each other.

3. The graphitization furnace according to claim 1 or 2, wherein an edge-shaped or arch-shaped transition section is provided between the upstream section (110) and the downstream section (120).

4. The graphitizing furnace according to any one of claims 1 to 3, wherein the graphitizing furnace is a vertical graphitizing furnace.

5. The graphitizing furnace is a vertical graphitizing furnace, and the downstream section (120) is located in the lower third, lower quarter, lower fifth, or lower sixth of the channel (100), more specifically, in the lower fifth or lower sixth of the channel (100), and in particular, in the lower fifth of the channel (100), where the lower part is closer to the Earth's center of gravity, according to any one of claims 1 to 4.

6. The graphitization furnace according to any one of claims 1 to 5, wherein the channel (110) includes a heating zone, a high-temperature reaction zone, and a cooling zone, and more specifically, the downstream section (120) is disposed in the high-temperature reaction zone and / or the cooling zone, and in particular is disposed in the cooling zone.

7. The graphitizing furnace according to any one of claims 1 to 6, wherein the upstream section (110) has a first length L1, the downstream section (120) has a second length L2, the upstream section (110) and the downstream section (120) are adjacent and have a combined length L3, and the ratio of L2 / L3 is less than 0.5, more specifically less than 0.3, and in particular less than 0.

2.

8. The graphitization furnace according to any one of claims 1 to 7, wherein the channel (100) has a first inner diameter D1, a second inner diameter D2, a third inner diameter D3, and a fourth inner diameter D4 in the planes of the first cross-section, the second cross-section, the third cross-section, and the fourth cross-section, respectively, and satisfies (D2-D1) / L1 < (D4-D3) / L2.

9. The graphitizing furnace is a continuous graphitizing furnace or a semi-batch graphitizing furnace, and in particular is a continuous graphitizing furnace, according to any one of claims 1 to 8.

10. The graphitization furnace according to any one of claims 1 to 9, wherein the graphitization furnace is configured such that the material flow within the graphitization furnace is gravity-assisted.

11. The channel (100) is α １ The first angle α is determined such that it satisfies = arctan((D2-D1) / (2×L1)) １ , and α ２ The second angle α is determined such that it satisfies = arctan((D4-D3) / (2×L2)) ２ It has α １ <α ２ The graphitizing furnace according to any one of claims 8 to 10.

12. The second angle α ２ is less than 45°, 35°, 30°, 20°, 15°, 10°, 9°, 8°, 7°, 6°, 5°, 4°, 3°, 2°, or 1°, and in particular the second angle α ２ The graphitizing furnace according to claim 11, wherein the angle is between approximately 0.1° and approximately 45°, more specifically between approximately 0.2° and 20°, and in particular between approximately 0.3° and approximately 10°.

13. the second angle α ２ is between about 0.1° and about 5°, more specifically between about 0.1° and about 2°, and particularly between about 0.1° and about 1.5°, the graphitization furnace according to claim 11 or 12.

14. The graphitizing furnace according to any one of claims 1 to 13, wherein the cross-section of the upstream section (110) or downstream section (120) perpendicular to the central channel (100) axis is elliptical or polygonal, more specifically octagonal, hexagonal, rectangular, square, or elliptical, and in particular rectangular or elliptical.

15. A method for preparing graphite from a carbonaceous material using a graphitization furnace according to any one of claims 1 to 14.

Images