Method and apparatus for producing ternary cathode material

Abstract

To provide a method for making a ternary cathode material to provide a better lithium battery.SOLUTION: In a method for producing a ternary cathode material (130) for a lithium battery by roasting a raw material (110) in a roaster (120), an atmosphere is provided to the roaster (120), and injection of a gas component (a) of the atmosphere into the roaster (120) is controlled in a closed-loop control manner on the basis of at least one process-influencing parameter being measured, as well as an apparatus for producing the ternary cathode material (130).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for producing ternary cathode materials for lithium batteries by roasting raw materials in a roasting kiln. Summary of the Invention [Problem to be solved by the invention]

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

[0003] The demand for long-range electric vehicles and hybrid vehicles has prompted the lithium battery industry to seek higher energy ratio cathode materials and corresponding solutions. So-called ternary cathode materials with higher energy density have become a trend in the industry. Such ternary cathode materials for lithium batteries are generally produced by roasting raw materials in a roasting kiln, which provides an atmosphere in the roasting kiln.

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

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

[0006] The method according to the invention is a method for producing ternary cathode materials for lithium batteries (or lithium ion batteries) by roasting raw materials in a roasting kiln, in which an atmosphere is provided. As the roasting kiln, a continuous roller hearth kiln or a pusher kiln is preferably used. 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 typically lasts between 10 and 18 hours.

[0007] The chemical reactions occurring in 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 2+ Ni 3+ However, Ni plays an important role in the process by helping to oxidize 3+ However, the ternary cathode material faces the problem of decomposition when the temperature prevailing in the roasting furnace is too high. Therefore, the ternary cathode material can easily be decomposed at high or too high a temperature. Therefore, the roasting process is 3+ The temperature should be kept as low as possible to ensure that the raw materials do not undergo decomposition. Furthermore, the aim is to provide a uniform temperature distribution and / or a uniform atmosphere within the kiln to allow all raw materials within the kiln to be exposed to the same process conditions.

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

[0010] Such a process-influencing parameter may be any parameter that influences the process. Preferably, the at least one process-influencing parameter is selected from parameters characterizing the raw materials, e.g. their specific composition, and / or parameters characterizing the atmosphere, e.g. the gas components present (oxygen, carbon dioxide, etc.) and their specific ratio or humidity, and / or parameters characterizing the ternary cathode material, e.g. its specific composition. To measure such parameters, corresponding measuring and / or analyzing means can be provided at 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 in the ceiling or side walls of the roasting kiln. In case of two or more zones, one of the gas injection lances can be used for each zone. Also, 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 with different process parameters, such as different zones with different temperatures and / or different speeds for moving the raw materials through the roasting kiln. Such gas injection lances allow very precise injection, resulting in a very uniform distribution of the gas in the roasting kiln. However, the zones may also be assigned to saggers present in the roasting kiln.

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

[0013] Preferably, the gas components are provided to the gas injection lance at a pressure between 0.5 and 10 bar. This makes it possible to select the velocity at which the gas leaves the lance or its nozzle. For example, the velocity can reach up to the speed of sound.

[0014] Advantageously, at least a part of the gas injection lance (or each of several lances) is made of a material such as steel (such as stainless steel or a heat-resistant alloy) coated with a ceramic, or the gas injection lance (or each of the lances) is made of a ceramic, which may be especially Al2O3, ZrO, SiC, etc. of very high purity, in order to prevent any direct contact between the material such as steel or other metal parts and the atmosphere in the kiln, especially in the case of its use as a coating.

[0015] The proposed method allows the raw materials to be exposed very uniformly to the oxygen required for such a process. In the case of several saggers present in a kiln, for example, all saggers can be exposed to sufficient oxygen. However, without such a method, the raw materials in the inner saggers had less contact with oxygen. In contrast, it was found that the raw materials in the outer saggers had a better chance of contacting oxygen. The roasting quality was therefore not as good as for the raw materials in the inner saggers or in the sagger line. The layer thickness of the raw materials 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, improves the quality stability of such ternary cathode materials, and further allows maintaining stable oxygen levels (or levels of other gas components) to meet the roasting process requirements of specific materials in each zone of the kiln. It also provides the potential for increased production capacity. Energy consumption and flow gas volumes can be reduced.

[0017] It should be noted that the proposed method can also be used to convert other raw materials into corresponding products by such roaster, 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 invention is an apparatus for producing ternary cathode material for lithium-ion batteries comprising a roasting kiln in which the atmosphere and the raw materials to be roasted can be provided. The apparatus also comprises injection means for injecting a gas component of the atmosphere into the roasting kiln based on at least one process-influencing parameter being measured, and control means for controlling the injection of the gas component in a closed-loop control manner. Measurement means for measuring such parameters can be provided. The injection means preferably comprise one or more gas injection lances, the gas injection lance having a nozzle at its end, the nozzle having a predetermined orientation between 0° and 90°, preferably between 20° and 70°, relative to the longitudinal axis of the gas injection lance. Preferably, the apparatus is adapted to carry out the method according to the invention.

[0019] For further embodiments and advantages of the device according to the invention, reference is made to the above description in order to avoid repetition.

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

[0021] [Figure 1] FIG. 1 shows diagrammatically an apparatus in which the method of the invention can be advantageously carried out. [Diagram 2] FIG. 2 shows diagrammatically in more detail a gas injection lance as part of the apparatus of FIG. [Diagram 3] FIG. 3 shows the gas injection lance of FIG. 2 in a different view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In Fig. 1, an apparatus 100 according to the invention in a preferred embodiment is shown. Such an apparatus can be used and adapted to carry out the method according to the invention. In the following, the apparatus and the corresponding method are described together.

[0023] The apparatus 100 includes a roaster kiln 120, for example in the form of a continuous roller hearth kiln, whereby the raw materials 110 are roasted to obtain the ternary cathode material 130. The raw materials 110 can be fed to the roaster kiln 120 at the roaster kiln 120, where the raw materials can be moved, for example, by a sagger line 125.

[0024] While moving inside the roaster kiln 120, the raw materials are roasted and undergo conversion to the desired ternary cathode material 130, see the above equation for conversion. After the raw materials are fully converted at the end of the roaster kiln 120, the product, i.e., ternary cathode material 130, can be removed from the kiln.

[0025] In the roaster kiln 120, an atmosphere is provided, which may contain different gas components such as (pure or nearly pure) oxygen, air and flue gas. By way of example, oxygen or an oxygen supply is indicated by the numeral a, air or an air supply is indicated by the numeral b and flue gas (such as nitrogen) or a flue gas supply is indicated by the numeral c.

[0026] These gas components a, b, c are supplied to the inside of the roasting kiln 120 via a control means or control module 150. The control module 150 allows the flow of each of these gas components to be controlled.

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

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

[0029] By way of example, there is provided measuring and / or analyzing means 111 for measuring or analysing parameters characterising the raw material 110, measuring and / or analyzing means 121 for measuring or analysing parameters characterising the atmosphere and measuring and / or analyzing means 131 for measuring or analysing the ternary cathode material 130. 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 vary (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 varied as necessary or advantageous. The pressure of the roaster kiln atmosphere can also be measured and controlled.

[0031] In Figure 2, the gas injection lance 140 that is part of the apparatus 100 of Figure 1 is shown in more detail and in perspective view. In Figure 3, the gas injection lance 140 of Figure 2 is shown in cross-section.

[0032] From the left end, oxygen can be supplied to a gas injection lance 140. When this lance 140 is supplied to the roaster kiln 120, the oxygen can be transferred into the kiln. At the right or inlet end 141, the gas injection lance 140 includes a nozzle 142. This nozzle 142 is provided in the form of a channel that is at an angle to the longitudinal direction or axis of the gas injection lance 140 (and preferably to other directions as well).

[0033] With such a nozzle (and multiple nozzles can be provided on the lance), oxygen can be injected into the kiln at a desired velocity and in a desired direction. The final direction in which the oxygen is injected is determined by the orientation of the nozzles (or channels) 142 in the gas injection lance 140 and by the orientation in which the gas injection lance 140 is positioned within the kiln 120.

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

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

Claims

[Claim 1] A method for producing a ternary cathode material (130) for a lithium battery by roasting a raw material (110) in a roasting kiln (120), comprising providing an atmosphere in the roasting kiln (120), The injection of the atmospheric gas component (a) into the roasting kiln (120) is controlled in a closed loop control manner based on at least one process-influencing parameter being measured. method.

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