Calcination container for cathode material of secondary battery

Abstract

The present invention relates to a firing container for a cathode material of a secondary battery. According to one embodiment, the firing container for a cathode material of a secondary battery comprises at least one saddle. The saddle comprises an outer body portion having a box shape with an open top, and an inner body portion located inside the outer body portion and containing a firing material. The inner body portion comprises an inner bottom portion that is seated on the bottom of the outer body portion and contacts the firing material. The inner bottom portion may have a material that is non-reactive with lithium. Accordingly, problems arising from a reaction with lithium during high-temperature firing can be prevented in advance.

Description

Technology Field

[0001] The present invention relates to a firing vessel for a secondary battery cathode material, and more specifically, to a firing vessel for a secondary battery cathode material in which the bottom portion of the firing vessel (e.g., a sager, etc.) that maintains contact with the firing material is improved with a material that is not reactive with lithium. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries refer to batteries that can be charged and discharged. Examples of secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, and lithium batteries.

[0003] In particular, lithium-ion batteries have the advantages of high energy density and voltage, long cycle life, and a low self-discharge rate. For this reason, lithium-ion batteries are commonly used in small electronic devices such as laptops, mobile phones, and tablets, as well as in large products such as electric or hybrid vehicles and power storage devices.

[0004] These secondary batteries are largely composed of a positive electrode, a negative electrode, a separator, and an electrolyte. Furthermore, a calcination process is essential for manufacturing electrode active materials, such as the positive electrode active material of secondary batteries.

[0005] As an example, the Roller Hearth Kiln (RHK) calcination method is mainly used. The RHK calcination method is a method in which lithium raw materials in powder form and metal raw materials are mixed and placed in a calcination vessel, and then the vessel is inserted into a horizontal furnace in which the temperature is set for each zone, and continuous calcination is carried out while moving horizontally.

[0006] Inside the calcination vessel, lithium raw materials in powder form and metal raw materials are contained in a mixed state, and diffusion and crystal growth occur as they react with each other due to the heat of high-temperature air supplied from inside the calcination furnace.

[0007] The firing vessel is provided in the form of a box-shaped vessel with an open top, i.e., a sagger, stacked vertically in multiple layers. A receiving space for holding the firing material is provided on the inner side of the open-top sagger, and gases supplied from within the firing furnace, namely bottom supply gases and side supply gases, can flow into the receiving space.

[0008] However, conventionally, the material of the sagger was made of mullite. In other words, in the case of conventional saggers, even the bottom surface in contact with the sintering material was entirely made of mullite. Consequently, there were various problems caused by the reaction with lithium during the synthesis of the lithium secondary battery cathode material, such as non-uniformity in the Li / Me ratio due to contact with the sintering material during high-temperature sintering, and surface delamination inside the sagger.

[0009] As a prior art related to the present invention, there is Korean Registered Patent Publication No. 10-1956559 (March 11, 2019, publication date), and the said prior art discloses a calcination vessel capable of gas circulation. Prior art literature

[0010] Republic of Korea Registered Patent Publication No. 10-1956559 The problem to be solved

[0011] The objective of the present invention is to provide a secondary battery cathode material firing container capable of solving various conventional problems caused by reaction with lithium by applying a material that is non-reactive with lithium to the bottom portion of the firing container (e.g., a sager, etc.) in which the firing material comes into contact.

[0012] Another objective of the present invention is to provide a secondary battery cathode material firing vessel capable of introducing gas using a supply hole formed in the bottom portion during lower air supply within the firing furnace.

[0013] Another objective of the present invention is to provide a secondary battery cathode material firing vessel capable of introducing gas using a supply hole formed in the sidewall when supplying gas from the side within the firing furnace.

[0014] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0015] According to one aspect of the present invention, a secondary battery cathode material firing container can be provided that solves problems arising from a reaction with lithium by applying a material that is not reactive with lithium to the area where the firing material comes into contact.

[0016] A secondary battery cathode material firing container according to one embodiment is a secondary battery cathode material firing container comprising at least one sagger, wherein the sagger may include an outer body portion having a box shape with an open top, and an inner body portion located inside the outer body portion and containing a firing material. The inner body portion may include an inner bottom portion that is seated on the bottom of the outer body portion and contacts the firing material. The inner bottom portion may have a material that is not reactive with lithium.

[0017] According to one embodiment, the inner bottom portion may be made of a material comprising one or more of alumina, silicon carbide (SiC), and tungsten carbide (WC).

[0018] According to one embodiment, the outer body part may be made of Mullite material.

[0019] According to one embodiment, the outer body portion may be provided with at least one first air supply hole for introducing gas supplied from the bottom.

[0020] According to one embodiment, at least one second air supply hole may be provided between the outer body part and the inner body part to introduce gas supplied from the side.

[0021] In addition, a secondary battery cathode material firing vessel according to one embodiment is a secondary battery cathode material firing vessel comprising at least one sagger, wherein the sagger may include an outer body portion having a box shape with an open top, and an inner body portion located inside the outer body portion. The outer body portion may include an outer bottom portion forming an outer bottom, and an outer side wall portion surrounding all four sides of the outer bottom portion at a set height. The inner body portion may include an inner bottom portion seated on the outer bottom portion and in contact with the firing material, and an inner side wall portion connected to the inner bottom portion and located inside the outer side wall portion. The inner bottom portion may have a material that is not reactive with lithium.

[0022] According to one embodiment, the inner bottom portion may be made of a material comprising one or more of alumina, silicon carbide (SiC), and tungsten carbide (WC).

[0023] According to one embodiment, the outer body portion may be made of Mullite material.

[0024] According to one embodiment, the outer bottom portion may have a square plate shape. The outer side wall portion protrudes at a set height from the edge of the outer bottom portion and may form a square wall surface that divides the inner and outer parts of the outer body portion. The inner bottom portion has a square plate shape that is reduced compared to the outer bottom portion and may accommodate a sintered material on its upper side.

[0025] According to one embodiment, the inner side wall portion may be connected to the outer side wall portion at the same height by standing up from the edge of the inner bottom portion. The inner surface of the outer side wall portion and the outer surface of the inner side wall portion may face each other and make surface contact with a set area.

[0026] According to one embodiment, the inner side wall and the outer side wall may be made of the same material.

[0027] According to one embodiment, a first fastening portion including a first fastening groove may be provided on the inner surface of the outer side wall portion. A second fastening portion including a second fastening groove corresponding to the first fastening groove may be provided on the outer surface of the inner side wall portion.

[0028] According to one embodiment, the outer side wall portion and the inner side wall portion may be surface-bonded to each other by curing of an auxiliary material such as a ceramic adhesive. Alternatively, a pin may be coupled to the first and second fastening groove portions of each of the outer side wall portion and the inner side wall portion to fix the connection position.

[0029] According to one embodiment, the outer bottom portion may be provided with at least one first air supply hole for introducing gas supplied from the bottom. The first air supply hole can introduce the gas supplied from the bottom through the space between the outer bottom portion and the inner bottom portion to the sintering material.

[0030] According to one embodiment, the lower end of the inner sidewall portion may be connected to the edge of the inner bottom portion with an inward gap from the outer sidewall portion. The upper end of the inner sidewall portion may be connected outwardly toward the outer sidewall portion. Between the upper end and the lower end of the inner sidewall portion, an inclined portion may be provided that is positioned at an angle, forming a predetermined gap with the outer sidewall portion.

[0031] According to one embodiment, the upper portion of the inner side wall may protrude higher than the lower height of the window portion located on the upper part of the outer side wall. At least one second air supply hole may be provided between the protruding portion of the inner side wall and the outer side wall to introduce gas supplied from the side. The second air supply hole may introduce gas supplied from the side through the gap to the sintering material.

[0032] Specific details of other embodiments are included in the specific details and drawings for carrying out the invention. Effects of the invention

[0033] According to the present invention, a material that is not reactive with lithium, such as alumina, silicon carbide (SiC), or tungsten carbide (WC), can be applied to the bottom portion of a firing container (i.e., a sagger) in which a firing material comes into contact. Accordingly, conventional problems caused by reaction with lithium during high-temperature firing, such as non-uniformity in the Li / Me ratio due to contact with the firing material during high-temperature firing and surface peeling inside the sagger, can be prevented in advance.

[0034] In addition, according to the present invention, gas can be introduced using a lower hole formed in the bottom part of the sagger during bottom air supply within the kiln. Accordingly, there is an advantage in that the bottom air supply effect is improved.

[0035] In addition, according to the present invention, gas can be introduced by utilizing a side opening formed in the side wall of the sagger during side air supply within the kiln. Accordingly, there is an advantage in that the side air supply effect is enhanced.

[0036] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0037] FIG. 1 is a simplified perspective view illustrating a secondary battery cathode material firing container according to a first embodiment. FIG. 2 is an exploded perspective view briefly illustrating a sagger, which is a secondary battery cathode material firing container according to the first embodiment. FIG. 3 is a simplified plan view illustrating a secondary battery cathode material firing container according to the first embodiment. FIG. 4 is a simplified cross-sectional view illustrating a secondary battery cathode material firing container according to the first embodiment. FIG. 5 is a disassembled cross-sectional view of a sagger, which is a secondary battery cathode material firing container according to the first embodiment. FIG. 6 is a cross-sectional view showing a structure in which a lower hole is formed in the outer bottom portion of a sagger, which is a secondary battery cathode material firing container according to the first embodiment. FIG. 7 is a plan view showing the arrangement shape of a sagger, which is a secondary battery cathode material firing container according to the second embodiment. FIG. 8 is a simplified perspective view illustrating a secondary battery cathode material firing container according to a second embodiment. FIG. 9 is a simplified cross-sectional view illustrating a secondary battery cathode material firing container according to a second embodiment. FIG. 10 is a perspective view illustrating another embodiment of a sagger, which is a secondary battery cathode material firing container according to the second embodiment. Specific details for implementing the invention

[0038] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0039] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0040] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0041] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0042] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0043] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0044] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0045] Hereinafter, a secondary battery cathode material firing container (hereinafter, firing container) according to various embodiments will be described in detail with reference to the attached drawings.

[0046] In the drawing, the X direction may refer to the front-back direction (or left-right direction), the Y direction may refer to the left-right direction (or front-back direction or transport direction), and the Z direction may refer to the up-down direction (or height direction or stacking direction).

[0047] [Sintering vessel according to the first embodiment]

[0048] FIG. 1 is a simplified perspective view of a firing vessel according to a first embodiment, FIG. 2 is a simplified exploded perspective view of a firing vessel according to a first embodiment, and FIG. 3 is a simplified plan view of a firing vessel according to a first embodiment. FIG. 4 shows a cross-section of the firing vessel according to a first embodiment after assembly, and FIG. 5 shows a disassembled cross-section of the firing vessel according to a first embodiment before assembly. FIG. 6 shows a cross-section of the firing vessel according to a first embodiment with a lower hole formed therein.

[0049] As described, the firing vessel according to the first embodiment may include at least one sagger (100).

[0050] A firing vessel refers to a refractory vessel that accommodates a firing material and is introduced into a firing furnace to move the firing material horizontally within the firing furnace. According to a preferred embodiment, the firing material may be continuously fired using a Roller Hearth Kiln (RHK) firing method, etc.

[0051] The firing vessel according to the first embodiment may include one or more new containers (100).

[0052] The sage (100) may include an outer body part (110) having a box shape with an open top, and an inner body part (120) located inside the outer body part (110). At this time, the sintered material may be received inside the inner body part (120). In other words, a receiving space in which the powdered sintered material is received (or filled) may be formed inside the inner body part (120).

[0053] Additionally, the inner body portion (120) may include an inner bottom portion (121) that is seated on the bottom of the outer body portion (110). The inner bottom portion (121) may form the bottom of a receiving space in which a sintered material is received (or filled) and may be maintained in contact with the sintered material.

[0054] Preferably, the inner bottom portion (121) may have a material that is not reactive with lithium. The conventional sagger was made entirely of mullite material, and in particular, even the bottom of the receiving space that maintains contact with the sintering material was made of mullite material. Because of this, the conventional sagger had various problems caused by reaction with lithium during the synthesis of the lithium secondary battery cathode material, such as non-uniformity in the Li / Me ratio due to contact with the sintering material during high-temperature sintering, and surface peeling inside the sagger.

[0055] According to the first embodiment, the sagger (100) includes an outer body portion (110) and an inner body portion (120), and the inner bottom portion (121) of the inner body portion (120) that maintains contact with the sintered material may be made of a material that is not reactive with lithium.

[0056] Preferably, the inner bottom portion (121) may be made of an alumina material that is not reactive with lithium. Additionally, preferably, the inner bottom portion (121) may be made of a silicon carbide (SiC) or tungsten carbide (WC) material that is not reactive with lithium. Furthermore, the inner bottom portion (121) may be formed by including one or more materials among alumina, silicon carbide (SiC), and tungsten carbide (WC). In addition, the inner bottom portion (121) may be used in a firing vessel using a material obvious to a person skilled in the art, and any material that is not reactive with lithium may be used without limitation.

[0057] According to the first embodiment, the outer body portion (110) may be made of a mullite material. Additionally, the remaining portion of the inner body portion (120), excluding the inner bottom portion (121) which requires contact with the firing material during high-temperature firing, for example, the inner side wall portion (122) to be described later, may be made of a mullite material.

[0058] Additionally, the outer body portion (110) may be provided with at least one first air supply hole (116) (see FIG. 6) for introducing gas supplied from the bottom into a receiving space in which a sintering material is received (or filled). In the sintering furnace, gas may be supplied from the bottom. The first air supply hole (116) (see FIG. 6) may introduce the gas (A) supplied from the bottom toward the sintering material. A detailed description of the first air supply hole (116) (see FIG. 6) will be provided in detail during the description of FIG. 6.

[0059] Additionally, between the outer body portion (110) and the inner body portion (120), at least one second air supply hole (126) (see FIG. 9) may be provided to introduce gas supplied from the side (i.e., side supply) toward the firing material. Gas may be supplied from the side within the firing furnace. The second air supply hole (126) (see FIG. 9) may introduce the gas (A) supplied from the side toward the firing material. A detailed description regarding the second air supply hole (126) (see FIG. 9) will be provided in detail during the description of FIG. 9.

[0060] Hereinafter, the detailed structure of the firing vessel according to the first embodiment will be examined in more detail.

[0061] Referring to FIGS. 1 to 5, the firing vessel according to the first embodiment may include one or more saggars (100).

[0062] The new device (100) may include an outer body part (110) having a box shape with an open top, and an inner body part (120) located inside the outer body part (110) and accommodating a sintered material.

[0063] The outer body part (110) may include an outer bottom part (111) that forms the outer bottom of the new thing (100).

[0064] In addition, the outer body portion (110) may include an outer side wall portion (112) that surrounds the outer bottom portion (111) at a set height.

[0065] The outer body part (110) may include an outer bottom part (111) and an outer side wall part (112), and may have a rectangular box shape with only the top open.

[0066] The inner body part (120) may include a plate-shaped inner bottom part (121) that is seated on the upper surface of the outer bottom part (111) with a predetermined thickness.

[0067] The inner bottom portion (121) can provide a bottom surface of a receiving space in which a sintered material is received (or filled). The inner bottom portion (121) can maintain contact between the sintered material received (or filled) in the receiving space and the sintered material.

[0068] Additionally, the inner body portion (120) may include an inner side wall portion (122) that is connected to the inner bottom portion (121) and is in close contact with the inside of the outer side wall portion (112).

[0069] The lower portion of the inner side wall (122) can be connected perpendicularly to the edge of the inner bottom portion (121). Additionally, the upper portion of the inner side wall (122) can be connected to the outer side wall (112) so that their upper portions match in height. Furthermore, the inner side wall (122) and the outer side wall (112) can have a structure in which they are closely connected to each other (see FIG. 4).

[0070] The inner bottom portion (121) may have a material that is not reactive with lithium. The inner bottom portion (121) is a part that maintains contact with the firing material during high-temperature firing, and in order to prevent various problems caused by reactivity with lithium in advance, a material that is not reactive with lithium may be used.

[0071] The inner bottom portion (121) may be made of one of alumina, carbide (SiC), or tungsten carbide (WC) that is not reactive with lithium. Additionally, the inner bottom portion (121) may include one or more of alumina, silicon carbide (SiC), and tungsten carbide (WC).

[0072] The outer body part (110) may be made of Mullite material. In other words, the outer bottom part (111) and the outer side wall part (112) may both be made of Mullite material.

[0073] The remaining part of the inner body (120) that does not require contact with the sintered material, namely the inner side wall (122), can be made of Mullite material, just like the outer body (110).

[0074] Referring to FIGS. 1 to 3, the outer bottom portion (111) may have a square plate shape.

[0075] The outer side wall portion (112) can protrude at a set height from each of the square edges of the outer bottom portion (111) to form a square wall surface that divides the inner and outer parts of the outer body portion (110).

[0076] The inner bottom portion (121) may have a square plate shape with a reduced planar size compared to the outer bottom portion (111). The inner bottom portion (121) may provide a bottom surface of a receiving space in which a sintered material is received (or filled).

[0077] The inner side wall portion (122) may have a structure that stands upright from the edge of the outer bottom portion (111). The inner side wall portion (122) may have the same height as the outer side wall portion (112). The inner surface of the outer side wall portion (112) and the outer surface of the inner side wall portion (122) may face each other and be joined (see FIG. 4).

[0078] The inner side wall portion (122) may have the same material as the outer side wall portion (112). Accordingly, the inner side wall portion (122) and the outer side wall portion (112) can minimize the effects of thermal expansion and contraction during high-temperature firing in a structure in which they are in contact with each other. Preferably, the inner side wall portion (122) and the outer side wall portion (112) may be made of the same mullite material.

[0079] According to the first embodiment, the outer body portion (110) has a box shape with an open top, and the inner body portion (120) is located inside the outer body portion (110) and accommodates a sintered material. The inner body portion (120) is positioned inside the outer body portion (110). As shown in FIG. 4, a coupling structure including mutually corresponding fastening grooves (1141, 1241) and pins (1142) may be formed between the inner body portion (120) and the outer body portion (110) as one embodiment, and the inner body portion (120) may be located and fixed inside the outer body portion (110) by this coupling structure.

[0080] delete

[0081] delete

[0082] In addition, the connection position can be fixed by applying ceramic adhesive to the bonding surface between the outer side wall (112) and the inner side wall (122) to firmly bond them together, and by combining the adhesive part (115) and the pin (1242).

[0083] Referring to FIG. 5, it shows a structure in which an inner body (120), that is, an inner bottom part (121) and an inner side wall part (122), are combined inside an outer body (110).

[0084] Meanwhile, referring to FIG. 6, the outer bottom portion (110) may be provided with a first air supply hole (116). The first air supply hole (116) is a hole formed to allow gas (A) supplied from the bottom within the firing furnace to flow into the interior, that is, toward the firing material, through the outer bottom portion (110). The gas (A) introduced through this first air supply hole (116) can flow into the interior of the sagger (100) through a passage (i.e., a gap or clearance) provided between the outer bottom portion (111) and the inner bottom portion (121), and can introduce gas to the firing material.

[0085] [Sintering vessel according to the second embodiment]

[0086] FIG. 7 is a plan view showing the arrangement of a firing vessel in a firing furnace according to a second embodiment, FIG. 8 is a simplified perspective view of a firing vessel according to a second embodiment, and FIG. 9 is a simplified cross-sectional view of a firing vessel according to a second embodiment.

[0087] Referring to FIG. 7, the sagger (100) can move along a set conveying direction (W) inside the kiln while containing (or being filled with) the firing material. At this time, gas (A) can be supplied (i.e., side supply) to the side of the sagger (100) inside the kiln. The firing container (100) according to the second embodiment to be described below has the advantage of being able to enhance the side supply effect.

[0088] Referring to FIGS. 8 and 9, a sagger (100) according to the second embodiment may include an outer body portion (110) and an inner body portion (120) located inside the outer body portion (110) and accommodating a sintered material.

[0089] The outer body portion (110) may include an outer bottom portion (111) that forms the outer bottom of the new body (100). In addition, the outer body portion (110) may include an outer side wall portion (112) that surrounds the outer bottom portion (111) at a set height.

[0090] According to the second embodiment, the inner body portion (120) may include a plate-shaped inner bottom portion (121) that is seated on the upper surface of the outer bottom portion (111) with a predetermined thickness.

[0091] The inner bottom portion (121) can provide a bottom surface of a receiving space in which a sintered material is received (or filled). The inner bottom portion (121) can maintain contact between the sintered material received (or filled) in the receiving space and the sintered material.

[0092] The inner body portion (120) may include an inner side wall portion (122) that is connected to the inner bottom portion (121) and is positioned obliquely on the side of the outer side wall portion (112).

[0093] Referring to FIG. 9, in the firing vessel (100) according to the second embodiment, the lower portion (1223) of the inner side wall portion (122) may be connected to the edge of the inner bottom portion (111) with a gap inward from the outer side wall portion (112). Additionally, the upper portion (1222) of the inner side wall portion (122) may be connected outwardly toward the outer side wall portion (112).

[0094] At this time, an inclined section (1221) inclined at a predetermined angle may be formed between the upper section (1222) and the lower section (1223) of the inner side wall section (122). The inclined section (1221) forms a predetermined gap space with the outer side wall section (112) and can form a flow path when gas (A) supplied from the side flows in (see FIG. 9).

[0095] More specifically, according to the second embodiment, the upper portion (1222) of the inner side wall portion (122) may have a structure that protrudes higher by a set height than the lower portion (113) of the window portion located on the upper part of the outer side wall portion (112) (see FIG. 9).

[0096] At this time, the protruding portion of the inner side wall (122), that is, the upper portion (1222) of the inner side wall (122) that protrudes higher than the lower portion of the window (113), may have a predetermined opening structure between it and the upper portion of the outer side wall (112). This opening structure may be used as a second air supply hole (126).

[0097] The second air supply hole (126) can introduce gas (A) supplied from the side inside the kiln into the interior of the sagger (100).

[0098] When gas (A) supplied from the side is introduced through the second supply hole (126), the gas supplied from the side can be introduced to the firing material by utilizing the gap provided between the inclined portion (1221) of the inner side wall portion (122) and the outer side wall portion (112) as a flow path.

[0099] Meanwhile, FIG. 10 is a perspective view illustrating another embodiment of a firing vessel according to the second embodiment.

[0100] Referring to FIG. 10, the inner side wall portion (122) can be arranged with a width size corresponding to the window portion (113) of the outer side wall portion (112).

[0101] Specifically, the inner side wall portion (122) has a height that protrudes higher than the bottom of the window portion (113) and may have a width size corresponding to the width of the window portion (113). According to this structure, the gas supplied from the side can be introduced through a second supply hole (126) (see FIG. 9) between the inner side wall portion (122) and the outer side wall portion (112) that protrudes higher than the bottom of the window portion (113).

[0102] As described above, according to the present invention, a material that is not reactive with lithium can be applied to the bottom surface of the sagger in contact with the sintering material. According to various embodiments, materials such as alumina, silicon carbide (SiC), and tungsten carbide (WC) can be applied to the bottom surface of the sagger in contact with the sintering material. Accordingly, various problems caused by reaction with lithium during high-temperature sintering, such as non-uniformity of the Li / Me ratio at the contact area with the sintering material, problems of reduced durability due to surface peeling inside the sagger, and problems of increased defects, can be prevented in advance.

[0103] Furthermore, according to the present invention, a lower air supply channel capable of gas inflow is formed on the bottom side of the sagger, taking into account the lower air supply within the kiln, thereby improving the effect of the lower air supply.

[0104] Furthermore, according to the present invention, a side flow path capable of gas inflow is formed on the sidewall side of the sagger in consideration of side air supply within the kiln, thereby improving the side air supply effect.

[0105] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized. Explanation of the symbols

[0106] 100: Firing vessel (or new one) 110: Outer body part 111: Outer bottom 112: Outer side wall 113: Window section 114: First connecting part 1141: 1st Signing Home 1142: Pin 115: Adhesive 116: 1st Supply Hole 120: Inner Body 121: Inner bottom 122: Inner side wall 1221: Inclined section 1222: Top section 1223: Bottom section 123: Window section 124: Second connecting part 1241: Sign Home 126: Second supply hole

Claims

Claim 1 A secondary battery cathode material firing vessel comprising at least one sagger, wherein the sagger comprises: an outer body portion having a box shape with an open top; and an inner body portion located inside the outer body portion and containing a firing material inside; wherein the inner body portion comprises an inner bottom portion seated on the bottom of the outer body portion and in contact with the firing material; wherein the inner bottom portion has a material that is not reactive with lithium, and gas supplied from the side is introduced between the outer body portion and the inner body portion. Claim 2 A secondary battery cathode material firing container according to claim 1, wherein the inner bottom portion is made of a material comprising one or more of alumina, silicon carbide (SiC), and tungsten carbide (WC). Claim 3 A secondary battery cathode material firing container according to claim 1, wherein the outer body portion is made of mullite material. Claim 4 A secondary battery positive material firing container according to claim 1, wherein the outer body portion is provided with at least one first supply hole for introducing gas supplied from the bottom. Claim 5 A secondary battery cathode material firing container according to claim 1, further comprising at least one second air supply hole provided between the outer body portion and the inner body portion, for introducing gas supplied from the side into the interior of the sagger. Claim 6 A secondary battery cathode material firing vessel comprising at least one sagger, wherein the sagger comprises: an outer body portion having a box shape with an open top; and an inner body portion located inside the outer body portion; wherein the outer body portion comprises: an outer bottom portion forming an outer bottom; and an outer side wall portion surrounding all four sides of the outer bottom portion at a set height; wherein the inner body portion comprises: an inner bottom portion seated on the outer bottom portion and in contact with the firing material; and an inner side wall portion connected to the inner bottom portion and located inside the outer side wall portion; wherein the inner bottom portion has a material that is not reactive with lithium, and gas supplied from the side is introduced between the outer body portion and the inner body portion. Claim 7 In claim 6, the inner bottom portion is a secondary battery cathode material firing container made of a material comprising one or more of alumina, silicon carbide (SiC), and tungsten carbide (WC). Claim 8 In claim 6, the outer body portion is a secondary battery cathode material firing container made of mullite material. Claim 9 A secondary battery cathode material firing container according to claim 6, wherein the outer bottom portion has a square plate shape, the outer side wall portion protrudes at a set height from the edge of the outer bottom portion and forms a square wall surface that divides the inner and outer parts of the outer body portion, and the inner bottom portion has a square plate shape that is reduced compared to the outer bottom portion and accommodates a firing material on the upper part. Claim 10 A secondary battery positive electrode material firing container according to claim 9, wherein the inner side wall portion is erected upward from the edge of the inner bottom portion and connected to the outer side wall portion at the same height, and the inner surface of the outer side wall portion and the outer surface of the inner side wall portion face each other and make surface contact. Claim 11 A secondary battery cathode material firing container according to claim 10, wherein the inner side wall portion and the outer side wall portion are made of the same material. Claim 12 A secondary battery cathode material firing container according to claim 10, wherein the inner surface of the outer side wall portion is provided with a first fastening portion including a first fastening projection or groove, and the outer surface of the inner side wall portion is provided with a second fastening portion including a second fastening groove or projection corresponding to the first fastening projection or groove, and the outer side wall portion and the inner side wall portion are fixed in a connection position by mutual surface contact through fastening between the first and second fastening portions. Claim 13 A secondary battery cathode material firing container according to claim 9, wherein the outer bottom portion is provided with at least one first air supply hole for introducing gas supplied from the bottom, and the first air supply hole introduces gas supplied from the bottom through the space between the outer bottom portion and the inner bottom portion to the firing material. Claim 14 A secondary battery cathode material firing container according to claim 9, wherein the lower portion of the inner side wall is connected to the edge of the inner bottom portion with an inward gap from the outer side wall portion, the upper portion of the inner side wall is connected outwardly toward the outer side wall portion, and an inclined portion is provided between the upper portion and the lower portion of the inner side wall portion, forming a predetermined gap with the outer side wall portion. Claim 15 In claim 14, the upper portion of the inner side wall protrudes higher than the lower height of the window portion located above the outer side wall portion, and further comprises at least one second air supply hole provided between the protruding portion of the inner side wall portion and the outer side wall portion, which introduces gas supplied from the side into the interior of the sagger; and the second air supply hole introduces gas supplied from the side through the gap to the calcination material, a secondary battery cathode material calcination container.

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