Crucible structure for carbonizing negative electrode material of lithium battery

Abstract

The utility model discloses a lithium battery negative electrode material carbonization crucible structure, the carbonization of a graphite negative electrode material comprises pre-carbonization and secondary coating carbonization, the crucible comprises a crucible main body, an upper cover, an inner cover and an oxygen isolation powder layer, and by arranging a double-layer top cover, the effects of isolating flame and ensuring the air tightness in the crucible are achieved; and the space between the lithium battery graphite negative electrode material and the upper cover is further filled with the oxygen isolation powder layer, and the oxygen isolation powder layer can play a heat transfer role and can also consume oxygen entering the crucible main body, so that the negative electrode material is prevented from being oxidized. According to the crucible structure for carbonizing the cathode material of the lithium battery, the oxygen content can be reduced, the air tightness of the crucible is ensured, and the cathode material in the crucible is prevented from being oxidized.

Description

Technical Field

[0001] The utility model relates to the technical field of crucibles, in particular to a carbonized crucible structure for negative electrode materials of lithium batteries. Background Art

[0002] Artificial graphite negative electrode materials need to be heated above 2800°C to transform the original dispersed structure into a layered graphite structure. Before the graphitization process, a pre-carbonization process is added to heat the material to 1000°C in an oxygen-proof manner, which can release 8-10% of volatiles, effectively increase the packing density of graphitized negative electrode materials, reduce the risk of furnace spraying, and at the same time greatly reduce the electrical energy consumed by graphitization. The pre-carbonization procedure uses a sealed, temperature-resistant, oxygen-proof crucible to load the negative electrode material, and heats it in a gas-fired tunnel kiln. When the graphitized artificial negative electrode material is used in power batteries and other fields, it needs to be secondary coated and secondary carbonized. Secondary carbonization requires more stringent oxygen isolation requirements than pre-carbonization, and requires higher heating temperature requirements. In order to solve the pre-carbonization and secondary coating carbonization, a new type of crucible needs to be designed. Utility Model Content

[0003] The utility model aims to provide a carbonization crucible structure for lithium battery negative electrode materials to solve the problems existing in the above-mentioned prior art, ensure the one-way airtightness of the crucible, prevent the negative electrode material coated with graphite in the crucible from being oxidized, and at the same time meet the requirements of heating carbonization.

[0004] To achieve the above purpose, the utility model provides the following solutions: The utility model provides a carbonized crucible structure of a lithium battery negative electrode material, including

[0005] A crucible, comprising a crucible body, an upper cover, an inner cover and an oxygen-isolating powder layer, wherein the crucible body is used to hold graphite negative electrode materials for lithium batteries; the upper cover is detachably connected to the top of the crucible body, and the crucible body and the upper cover are made of the same material; the inner cover is arranged in the crucible body, and the inner cover is arranged at an interval at the bottom of the upper cover; or graphite paper or graphite plate is arranged in the crucible body, and the graphite paper or graphite plate is arranged at the bottom of the upper cover, and the oxygen-isolating powder layer is arranged on the top or circumference of the inner cover or the graphite paper or graphite plate.

[0006] Preferably, the crucible body is made of any one of silicon carbide graphite material, oxide combined with silicon carbide material, or silicon nitride combined with silicon nitride material.

[0007] Preferably, the inner cover is made of graphite, carbon or oxygen-absorbing material.

[0008] Preferably, a circle of stepped grooves is provided on the inner wall of the crucible body near the upper edge, the inner cover is buckled in the stepped groove, the lithium battery graphite negative electrode material is placed at the lower bottom of the inner cover in the crucible body, and a layer of the oxygen-isolating powder layer is laid on the upper bottom of the inner cover.

[0009] Preferably, an inner crucible is provided in the crucible body, the inner crucible is placed in the crucible body, the lithium battery graphite negative electrode material is contained in the inner cavity of the inner crucible, and the inner cover is buckled on the top of the inner crucible.

[0010] Preferably, the diameter of the inner cover is smaller than the diameter of the upper cover.

[0011] Preferably, the oxygen-isolating powder layer is filled between the outer wall of the inner crucible and the inner wall of the crucible body.

[0012] Preferably, the inner crucible is made of graphite material or oxygen absorbing material.

[0013] Preferably, the inner crucible is spliced ​​by a segmented structure, and the spliced ​​gap is sealed by a curved sealing structure.

[0014] Preferably, the crucible body is spliced ​​by a segmented structure, and the spliced ​​gap is sealed by a curved sealing structure.

[0015] Preferably, the oxygen-isolating powder between the inner cover and the outer cover, and between the inner crucible and the crucible body is made of oxygen-absorbing materials such as various petroleum coke powders / carbon powders / activated carbon.

[0016] Compared with the prior art, the utility model has achieved the following beneficial technical effects:

[0017] The carbonized crucible structure of the negative electrode material of the lithium battery in the utility model comprises a crucible body, an upper cover, an inner cover and an oxygen-isolating powder layer. By setting a double-layer top cover, it can isolate the flame and ensure the airtightness of the inside of the crucible. An oxygen-isolating powder layer is also filled between the graphite negative electrode material of the lithium battery and the upper cover. The oxygen-isolating powder layer can not only play a role in heat transfer, but also consume the oxygen entering the crucible body, thereby preventing the oxidation of the negative electrode material. The carbonized crucible structure of the negative electrode material of the lithium battery in the utility model can reduce the oxygen content, ensure the airtightness of the crucible, and prevent the oxidation of the negative electrode material in the crucible. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a cross-sectional view of the overall structure of the carbonized crucible structure of the negative electrode material of the lithium battery in Example 1;

[0020] Figure 2 It is a schematic diagram of the structure of the upper cover in the first embodiment;

[0021] Figure 3 It is a schematic diagram of the structure of the inner cover in the first embodiment;

[0022] Figure 4 It is a cross-sectional view of the overall structure of the carbonized crucible structure of the negative electrode material of the lithium battery in Example 2;

[0023] Figure 5 It is a schematic diagram of the structure of the inner cover in the second embodiment;

[0024] Figure 6 This is a schematic diagram of the structure of the inner cover in the third embodiment;

[0025] Among them, 1. upper cover; 2. oxygen-isolating powder layer; 3. inner cover; 4. negative electrode material; 5. crucible body; 6. inner crucible. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] The utility model aims to provide a carbonized crucible structure for negative electrode materials of lithium batteries to solve the problems existing in the above-mentioned prior art, ensure the airtightness of the crucible and prevent the negative electrode materials in the crucible from being oxidized.

[0028] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] Embodiment 1

[0030] like Figure 1-Figure 3 As shown, this embodiment provides a carbonized crucible structure for a lithium battery negative electrode material, comprising

[0031] The crucible comprises a crucible body 5, an upper cover 1, an inner cover 3 and an oxygen-isolating powder layer 2. The crucible body 5 is used to hold graphite negative electrode materials for lithium batteries. The top of the crucible body 5 is detachably connected to the upper cover 1, and the crucible body 5 and the upper cover 1 are made of the same material. The crucible body 5 is provided with an inner cover 3, and the inner cover 3 is spaced apart from the bottom of the upper cover 1. The top of the inner cover 3 is provided with an oxygen-isolating powder layer 2.

[0032] In one embodiment, the crucible body 5 is made of any one of silicon carbide graphite material, oxide combined with silicon carbide material or silicon nitride combined with silicon nitride material, and the upper cover 1 and the crucible body 5 are made of the same material. Figure 2 As shown, the upper cover 1 has a stepped cross-section, the outer edge of the upper cover 1 is placed on the outer side of the top of the crucible body 5, and the inner edge of the upper cover 1 is located on the inner side of the top of the crucible body 5. The double-layer cover and the oxygen-isolating powder layer 2 can consume oxygen and prevent the oxidation of the negative electrode material 4.

[0033] In one embodiment, the inner cover 3 is made of graphite material, such as Figure 3 As shown, the inner cover 3 in this embodiment is in the form of a disc, and a circle of stepped grooves is provided on the inner wall of the crucible body 5 near the upper edge. The disc-shaped inner cover 3 is directly buckled in the stepped groove, and the diameter of the inner cover 3 is smaller than the diameter of the stepped groove. Therefore, the circumference and top of the inner cover 3 are filled with an oxygen-isolating powder layer 2; the negative electrode material 4 is placed at the bottom of the inner cover 3 in the crucible body 5.

[0034] Embodiment 2

[0035] like Figure 4-Figure 5 As shown, this embodiment provides a carbonized crucible structure for a lithium battery negative electrode material, comprising

[0036] Crucible, the crucible includes a crucible body 5, an upper cover 1, an inner cover 3 and an oxygen-isolating powder layer 2, the crucible body 5, the crucible body 5 is used to hold lithium battery graphite negative electrode material; the top of the crucible body 5 is detachably connected with the upper cover 1, and the crucible body 5 and the upper cover 1 are made of the same material; the crucible body 5 is provided with an inner cover 3, and the inner cover 3 is arranged at an interval at the bottom of the upper cover 1; the crucible body 5 is provided with an inner crucible 6, the inner crucible 6 is placed in the crucible body 5, the lithium battery graphite negative electrode material 4 is contained in the inner cavity of the inner crucible 6, and the inner cover 3 is buckled on the top of the inner crucible 6.

[0037] In one embodiment, if Figure 4-Figure 5 As shown, the diameter of the inner cover 3 is smaller than the diameter of the upper cover 1, and an oxygen-isolating powder layer 2 is filled between the outer wall of the inner crucible 6 and the inner wall of the crucible body 5, and an oxygen-isolating powder layer 2 is also filled between the circumference of the inner cover 3 and the inner wall of the crucible body 5.

[0038] In one embodiment, the inner crucible 6 is made of graphite material, the inner cover 3 is arranged in the same stepped form as the upper cover 1, the outer edge of the inner cover 3 is located outside the top of the inner crucible 6, and the inner edge of the inner cover 3 is located inside the top of the inner crucible 6. In this embodiment, the inner crucible 6 is spliced ​​in a segmented structure, and the splicing gap is closed by a linear sealing assembly method or a curved sealing assembly method.

[0039] Embodiment 3

[0040] like Figure 6 As shown, the carbonized crucible structure of the negative electrode material of the lithium battery in this embodiment is basically the same as the structure of the carbonized crucible structure of the negative electrode material of the lithium battery in Example 2. The only difference is that the crucible body 5 and the inner crucible 6 in this embodiment are both spliced ​​in a segmented structure, and the splicing gap is closed by a curved assembly method.

[0041] The carbonization crucible structure of the negative electrode material of the lithium battery in the utility model is carbonized by pre-carbonizing the negative electrode material of the lithium battery in the tunnel kiln by adjusting the appropriate air-fuel ratio, and then transferring the pre-carbonized negative electrode material of the lithium battery to the crucible for high-temperature carbonization. The crucible is provided with a double-layer top cover to isolate the flame and ensure the air tightness of the crucible. An oxygen-isolating powder layer 2 is also filled between the graphite negative electrode material of the lithium battery and the upper cover 1. The oxygen-isolating powder layer 2 can not only play a role in heat transfer, but also consume the oxygen entering the crucible body 5, thereby preventing the oxidation of the negative electrode material 4. The carbonization crucible structure of the negative electrode material of the lithium battery in the utility model can ensure the air tightness of the crucible and prevent the negative electrode material 4 in the crucible from being oxidized.

[0042] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0043] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A carbonized crucible structure for negative electrode materials of lithium batteries, characterized in that: include A crucible, comprising a crucible body, an upper cover, an inner cover and an oxygen-isolating powder layer, wherein the crucible body is used to hold graphite negative electrode materials for lithium batteries; the upper cover is detachably connected to the top of the crucible body, and the crucible body and the upper cover are made of the same material; the inner cover is arranged inside the crucible body, and the inner cover is arranged at intervals at the bottom of the upper cover; the oxygen-isolating powder layer is arranged on the top or circumference of the inner cover.

2. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 1, characterized in that: The crucible body is made of any one of silicon carbide graphite material, oxide combined with silicon carbide material or silicon nitride combined with silicon nitride material.

3. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 1, characterized in that: The inner cover is made of graphite material.

4. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 1, characterized in that: A circle of stepped grooves is provided on the inner wall of the crucible body near the upper edge, and the inner cover is buckled on the stepped groove. Lithium battery graphite negative electrode material is placed at the bottom of the inner cover in the crucible body, and a layer of the oxygen-isolating powder layer is laid on the bottom of the inner cover.

5. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 1, characterized in that: An inner crucible is arranged in the crucible body, the inner crucible is placed in the crucible body, a lithium battery graphite negative electrode material is placed in the inner cavity of the inner crucible, and the inner cover is buckled on the top of the inner crucible.

6. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 5, characterized in that: The diameter of the inner cover is smaller than the diameter of the upper cover.

7. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 6, characterized in that: The oxygen-isolating powder layer is filled between the outer wall of the inner crucible and the inner wall of the crucible body.

8. The carbonized crucible structure for negative electrode materials of lithium batteries according to claim 5, characterized in that: The inner crucible is made of graphite material.

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