Method and apparatus for manufacturing ternary cathode material

Abstract

1. A method for producing a ternary cathode material (130) for a lithium battery by roasting a raw material (110) in a roaster kiln (120), wherein an atmosphere is provided to the roaster kiln (120), and injection of a gas component (a) of the atmosphere into the roaster kiln (120) is controlled in a closed-loop control manner based on at least one measured process-influencing parameter and an apparatus for producing the ternary cathode material (130).

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a ternary cathode material for a lithium battery by roasting raw materials in a roasting kiln.

Summary of the Invention

Problems to be Solved by the Invention

[0002] The markets for electric vehicles and hybrid vehicles are growing rapidly. This has led to an increasing demand for lithium or lithium-ion batteries commonly used in the automotive industry. Lithium batteries contain, among other components, a cathode material and an anode material. The processes for manufacturing these materials and their components generally use gases such as oxygen, nitrogen, and argon.

[0003] Due to the requirements for long-range electric vehicles and hybrid vehicles, the lithium battery industry is required to pursue cathode materials with higher energy ratios and corresponding solutions. So-called ternary cathode materials with higher energy densities have become a trend in this industry. Such ternary cathode materials for lithium batteries are generally manufactured by roasting raw materials in a roasting kiln that provides an atmosphere within the roasting kiln.

[0004] The present invention aims to improve the possibility of obtaining a product from the raw materials roasted in a roasting kiln, and thus to provide a better lithium battery.

[0005] This object is achieved by providing a method and an apparatus according to the independent claims.

[0006] The present invention relates to a method for producing a ternary cathode material for lithium batteries (or lithium-ion batteries) by roasting raw materials in a roasting furnace, wherein an atmosphere is provided in the roasting furnace. A continuous roller hearth furnace or a pusher furnace is preferred as the roasting furnace. Common and preferred ternary cathode materials are nickel-cobalt manganese and nickel-cobalt aluminum. Typical temperatures used in such roasting processes are between 700°C and 1000°C, and the roasting process generally lasts for 10 to 18 hours.

[0007] The chemical reactions that occur during the roasting process can be described by the following equation, where M represents Ni (nickel), Mn (manganese), Co (cobalt), and / or Al (aluminum). M(OH)2 + 0.5Li2CO3 + 0.25O2 = L i MO2 + 0.5CO2 + H2O M(OH)2+LiOH.H2O+0.25O2=LiMO2+2.5H2O

[0008] In particular, oxygen is, for example, Ni 2+ Ni 3+ It plays an important role in the process because it helps in oxidation. However, Ni 3+ However, if the temperature reaching the roasting furnace is too high, it faces the problem of decomposition. Therefore, ternary cathode materials can easily decompose at high or excessively high temperatures. For this reason, the roasting process is Ni 3+ To ensure that the material does not decompose, its temperature should be kept as low as possible. Furthermore, the goal is to provide a uniform temperature distribution and / or atmosphere within the kiln, enabling all raw materials in the kiln to be exposed to the same process conditions.

[0009] According to the present invention, the injection of an atmosphere, preferably an oxygen gas component, into the roasting kiln is controlled by a closed-loop control system, i.e., by closed-loop control based on at least one process influence parameter that is measured. In particular, the closed-loop control is performed automatically by a control module or the like.

[0010] Such process influence parameters can be any parameters that influence the process. Preferably, at least one process influence parameter is selected from raw materials, e.g., parameters characterizing the specific composition of the raw materials, and / or parameters characterizing the atmosphere, e.g., the present gaseous components (oxygen, carbon dioxide, etc.) and their specific ratios or humidity, and / or parameters characterizing the ternary cathode material, e.g., its specific composition. To measure such parameters, corresponding measuring and / or analytical means can be provided in appropriate locations.

[0011] Advantageously, gas injection lances are used to inject gas components into one or more zones of the roasting kiln. In particular, the gas injection lances are installed or provided on the ceiling or side walls of the roasting kiln. In the case of two or more zones, one of those gas injection lances can be used for each zone. Alternatively, two or more of these gas injection lances can be used for one or more zones. The zones of the roasting kiln may be defined based on zones or regions having different process parameters, such as different zones having different temperatures and / or different speeds for moving raw materials through the roasting kiln. Such gas injection lances allow for very precise injection, resulting in very uniform distribution of gas in the roasting kiln. However, the zones may be assigned to saggars present within the roasting kiln.

[0012] For example, a gas injection lance (or each of several gas injection lances) is provided with one or more nozzles having a predetermined direction. The predetermined direction can preferably be selected between 0° and 90° with respect to the longitudinal axis of the roasting oven. In this way, the atmosphere, particularly the injected gas, can be moved in a desired direction. Furthermore, turbulence or gas flow movement may be generated as a result.

[0013] Preferably, the gas component is supplied to the gas injection lance at a pressure between 0.5 bar and 10 bar. This allows for selection of the velocity at which the gas exits the lance or its nozzle. For example, the velocity can reach the speed of sound.

[0014] Advantageously, at least some of the gas injection lances (or each of several lances) are made of a material such as ceramic-coated steel (such as stainless steel or a heat-resistant alloy), or the gas injection lances (or each of several lances) are made of ceramic. Such ceramics may be of particularly high purity, such as Al2O3, ZrO, or SiC, in order to prevent any direct contact between materials such as steel or other metal parts and the atmosphere inside the furnace, especially when used as a coating.

[0015] The proposed method allows the oxygen required for such a process to be exposed to the raw materials very uniformly. In the case of several saggars present in the kiln, for example, all saggars can be exposed to sufficient oxygen. However, without this method, the contact of raw materials with oxygen in the inner saggars was less. In contrast, the raw materials in the outer saggars were found to have a better chance of contact with oxygen. Therefore, the roasting quality was not as good as that of raw materials in the inner saggars or in the saggar line. The thickness of the raw material layers had to be made very thin. These drawbacks can be overcome with the proposed method.

[0016] The proposed method further improves the quality of ternary cathode materials for lithium battery manufacturing, enhances the quality stability of such ternary cathode materials, and makes it possible to maintain stable oxygen levels (or levels of other gas components) to meet the roasting process requirements of specific materials in each zone of the furnace. It also offers the potential for increased manufacturing capacity. Energy consumption and fluid gas volume can be reduced.

[0017] It should be noted that the proposed method may also be used to convert other raw materials into corresponding products using such a roasting oven. For example, lithium iron phosphate (LFP) cathode material or graphene anode material can be produced from the corresponding raw materials.

[0018] A further object of the present invention is an apparatus for producing ternary cathode material for lithium-ion batteries, comprising a roasting oven capable of providing a roasting atmosphere and raw materials. The apparatus also comprises an injection means for injecting a gaseous component of the atmosphere into the roasting oven based on at least one process influence parameter being measured, and a control means for controlling the injection of the gaseous component in a closed-loop control manner. Measuring means for measuring such parameters can be provided. The injection means preferably comprises one or more gas injection lances, each having a nozzle at its end, the nozzle having a predetermined direction between 0° and 90°, preferably between 20° and 70°, with respect to the longitudinal axis of the gas injection lance. Preferably, the apparatus is adapted to perform the method according to the present invention.

[0019] Further embodiments and advantages of the apparatus according to the present invention are described above to avoid repetition.

[0020] The present invention will now be further described with reference to the accompanying drawings illustrating preferred embodiments. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 schematically shows an apparatus that can advantageously implement the method of the present invention. [Figure 2] Figure 2 shows a more detailed schematic of the gas injection lance as part of the apparatus in Figure 1. [Figure 3] Figure 3 shows the gas injection lance from Figure 2 in a different diagram. [Modes for carrying out the invention]

[0022] In FIG. 1, an apparatus 100 according to the present invention in a preferred embodiment is shown. Such an apparatus can be used to execute the method according to the present invention and can be adapted. Hereinafter, the apparatus and the corresponding method will be described together.

[0023] The apparatus 100 includes, for example, a roasting kiln 120 in the form of a continuous roller hearth kiln, whereby the raw material 110 is roasted to obtain the ternary cathode material 130. The raw material 110 can be supplied to the roasting kiln 120 and the raw material can be moved, for example, on the sagger line 125.

[0024] The raw material is roasted and undergoes conversion to the desired ternary cathode material 130 while moving inside the roasting kiln 120. Refer to the above formula regarding the conversion. After the raw material is completely converted at the end of the roasting kiln 120, the product, i.e., the ternary cathode material 130, can be removed from the kiln.

[0025] In the roasting kiln 120, an atmosphere is provided, and the atmosphere includes different gas components such as oxygen (pure or almost pure), air, and flue gas. As an example, the oxygen or oxygen supply is indicated by the numeral a, the air or air supply is indicated by the numeral b, and the flue gas (such as nitrogen) or flue gas supply is indicated by the numeral c.

[0026] These gas components a, b, c are supplied into the roasting kiln 120 via a control means or control module 150. The control module 150 can control the respective flow rates of these gas components.

[0027] In the illustrated embodiment, the oxygen a is supplied to the roasting kiln 120 via three gas injection lances 140 provided in different zones 126 along the movement path of the raw material in the roasting kiln 120 as an example. The control module 150 can be adapted to distribute the oxygen a (i.e., the mass flow rate) provided to the control module among these three gas injection lances 140 according to a predetermined variable ratio.

[0028] To determine the currently preferred ratio of oxygen flow between the absolute mass flow rate of oxygen to one gas injection lance 140 and the other gas injection lance, different parameters affecting the roasting process can be measured and supplied to the control module to establish closed-loop control.

[0029] As an example, measuring and / or analytical means 111 for measuring or analyzing parameters characterizing the raw material 110, measuring and / or analytical means 121 for measuring or analyzing parameters characterizing the atmosphere, and measuring and / or analytical means 131 for measuring or analyzing the ternary cathode material 130 are provided. Each of these means can supply the measurement or analysis results in the form of a signal to the control module 150, which can then use these results to change (or maintain) the oxygen flow.

[0030] It should also be noted that the flow of air b and / or flue gas c can be similarly modified as needed or if convenient. Furthermore, the pressure of the roasting kiln atmosphere can be measured and controlled.

[0031] Figure 2 shows the gas injection lance 140, which is part of the apparatus 100 in Figure 1, in more detail and in a perspective view. Figure 3 shows the gas injection lance 140 of Figure 2 in a cross-sectional view.

[0032] Oxygen can be supplied to the gas injection lance 140 from the left end. When this lance 140 is supplied to the roasting kiln 120, the oxygen can be transferred into the kiln. On the right side or at the inlet end 141, the gas injection lance 140 includes a nozzle 142. This nozzle 142 is provided in the form of a channel having a certain angle with respect to the longitudinal direction or axis of the gas injection lance 140 (preferably with respect to other directions as well).

[0033] Such nozzles (multiple nozzles may be provided on the lance) allow oxygen to be injected into the roasting oven at a desired rate and in a desired direction. The final direction in which the oxygen is injected is determined by the orientation of the nozzle (or channel) 142 within the gas injection lance 140 and by the orientation in which the gas injection lance 140 is positioned within the roasting oven 120.

[0034] As mentioned above, the gas injection lance 140 can be made of ceramic material, or steel (or stainless steel) coated with such ceramic. Essentially, only a portion of the lance that is placed inside the roasting kiln needs to be coated or made of ceramic or other similar material to avoid damage due to oxidation.

[0035] By providing a desired number of such lances and orienting these lances (relative to their nozzles) as desired, a very uniform distribution of oxygen in the roasting furnace 120 or its atmosphere can be achieved. As a result, the ternary cathode material can be manufactured in a better and more efficient manner.

Claims

1. A method for producing a ternary cathode material (130) for lithium batteries by roasting raw materials (110) in a roasting oven (120), wherein an atmosphere is provided to the roasting oven (120), The roasting oven (120) is defined by a plurality of different zones (126) having different temperatures and / or different speeds, the raw material (110) moves through the plurality of zones (126) within the roasting oven (120), and the injection of the gaseous component (a) of the atmosphere into the roasting oven (120) is controlled in a closed-loop manner by control means (150) based on at least one measured process influence parameter. The gas component (a) is injected through a gas injection lance (140) located in one or more of the multiple zones (126) of the roasting oven (120). The control means (150) is characterized by distributing the gas component (a) to each of the arranged gas injection lances (140) in a predetermined variable ratio. method.

2. The method according to claim 1, wherein the gas injection lance (140) comprises one or more nozzles (142) having a predetermined direction.

3. The method according to claim 2, wherein the predetermined direction is selected between 0° and 90° with respect to the longitudinal axis of the roasting oven (120).

4. The method according to any one of claims 1 to 3, wherein the gas component is supplied to the gas injection lance (140) at a pressure between 0.5 bar and 10 bar.

5. The method according to any one of claims 1 to 4, wherein the gas injection lance (140) is made of a material that is at least partially coated with ceramic, or is made of ceramic.

6. The method according to any one of claims 1 to 5, wherein the at least one process influence parameter is selected from parameters characterizing the raw material (110) and / or the atmosphere and / or the ternary cathode material (130).

7. The method according to any one of claims 1 to 6, wherein the gas component (a) of the atmosphere is oxygen.

8. The method according to any one of claims 1 to 7, wherein the ternary cathode material (130) comprises nickel-cobalt manganese or nickel-cobalt aluminum.

9. The method according to any one of claims 1 to 8, wherein a continuous roller hearth kiln or a pusher kiln is used as the roasting kiln (120).

10. An apparatus (100) for manufacturing a ternary cathode material (130) for lithium-ion batteries, comprising a roasting oven (120) that can provide a roasting atmosphere and raw materials (110), The raw material (110) is configured to move within the roasting oven (120), which is defined by a plurality of different zones (126) having different temperatures and / or different speeds. The system includes an injection means (140) for injecting the gas component (a) of the atmosphere into the roasting oven (120), and further includes a control means (150) for controlling the injection of the gas component (a) in a closed-loop control manner based on at least one measured process influence parameter. The injection means (140) includes a plurality of gas injection lances, Multiple gas injection lances are arranged in one or more of the multiple zones (126) in the roasting oven (120) to which different process influence parameters are applied, and to inject the gas component (a). The control means (150) is characterized by distributing the gas component (a) to each of the arranged gas injection lances in a predetermined variable ratio. Apparatus (100).

11. The apparatus (100) according to claim 10, wherein the gas injection lance has a nozzle at its end, the nozzle has a predetermined direction between 0° and 90°, preferably between 20° and 70°, with respect to the longitudinal axis of the gas injection lance, and / or the gas injection lance is installed on the ceiling or side wall of the roasting oven.

12. The apparatus (100) according to claim 10 or 11, further adapted to perform the method described in any one of claims 2 to 9.

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