Method and device for producing a sodium-containing battery material

Abstract

The invention relates to a method for producing a sodium-containing battery material, having the following steps: a) providing a sodium-containing battery precursor mixture as a starting compound in the form of a solution, slurry, suspension, or in a solid aggregate state, b) introducing the sodium-containing battery precursor mixture into a first thermal reactor using a hot gas flow, c) thermally treating the sodium-containing battery precursor mixture carried by the hot gas flow at a temperature of 150°C to 1,200°C in the first thermal reactor, d) discharging the sodium-containing battery precursor material in a solid form from the first thermal reactor, e) introducing the sodium-containing battery precursor material from step d) into a second thermal reactor, f) thermally treating the sodium-containing battery precursor material at a temperature of 500°C to 1,200°C in the second thermal reactor and converting the sodium-containing battery precursor material into the sodium-containing battery material, and g) discharging the obtained sodium-containing battery material in a solid form from the second thermal reactor.

Description

[0001] Method and apparatus for the production of a sodium-containing battery material

[0002] DESCRIPTION

[0003] The invention relates to a particularly two-stage process and a device for producing a particularly nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material.

[0004] Devices for the thermal treatment of a raw material include, for example, pulsation reactors, as described in WO 02 / 072471 Al or the

[0005] DE 10 2004 044 266 Al and WO 2019 / 197147 Al are described.

[0006] Pulsation reactors are used, for example, for the thermal synthesis of a raw material to produce fine particles, especially fine materials.

[0007] The invention is based on the objective of providing a particularly environmentally friendly and efficient method and a corresponding device for the production of a sodium-containing battery material.

[0008] The first problem is solved according to the invention by the features of claim 1. The second problem is solved according to the invention by the features of claim 9.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] The inventive process for producing a sodium-containing battery material, in particular an active cathode material, is a two-stage thermal treatment process comprising at least the following process steps: a) providing a sodium-containing battery precursor mixture as a starting compound in the form of a solution, slurry, suspension or in a solid and moist state of matter, b) introducing the sodium-containing battery precursor mixture into a first thermal reactor with a hot gas stream, c) thermal treatment, in particular synthesis and / or drying, of the sodium-containing battery precursor mixture carried by the hot gas stream at a temperature of 150°C to 1.200°C in the first thermal reactor, d) subsequent extraction, in particular precipitation of the sodium-containing battery precursor material in solid form, in particular in powder form, from the first thermal reactor, e) introduction of the sodium-containing battery precursor material from step d) into a second thermal reactor, in particular without additives, f) thermal treatment, in particular calcination, of the sodium-containing battery precursor material at a temperature of 500°C to 1,200°C in the second thermal reactor and conversion of the sodium-containing battery precursor material into the sodium-containing battery material, and g) extraction, in particular precipitation, of the obtained sodium-containing battery material in solid form, in particular in powder form, from the second thermal reactor.

[0011] The process according to the invention is a two-stage process in which the synthesis and drying of the battery precursor mixture in the first reactor constitutes a first thermal treatment stage at a temperature of 150°C to 1,200°C, in particular from 200°C to 1,000°C or 300°C to 900°C, and the calcination and conversion of the dried battery precursor material into the battery material (also called active battery material) in the second reactor constitutes a second thermal treatment stage at a temperature of 500°C to 1,200°C, in particular from 600°C to 1,000°C or from 700°C to 900°C.

[0012] In other words, the sodium-containing battery precursor material undergoes a sequential two-stage thermal treatment, whereby the material is first discharged in solid form from the first thermal reactor and then transferred to the second thermal reactor for further processing. This sequential handling in solid form allows for improved control of the thermal treatment conditions in each reactor, resulting in increased phase purity and homogeneity of the final sodium-containing battery material. The separation of the thermal treatment steps also allows for the removal of volatile byproducts and precise adjustment of the reaction parameters, thereby improving the overall quality and performance characteristics of the manufactured battery material.

[0013] Surprisingly, it was found that sodium-containing starting material for active sodium-containing battery material to be produced as a solid powder can be efficiently calcined at temperatures exceeding those normally used for its synthesis / drying and calcination if the starting material, especially the battery precursor mixture, is thermally treated twice and / or if, in particular, the residence time (also called retention time) at these high temperatures is up to 1.The temperature of the sodium-containing battery material is maintained at 200 °C, preferably in the range of 700 °C to 900 °C, for an extremely short first thermal treatment for synthesis / drying, particularly in the millisecond range, for example, less than two seconds. During a second thermal treatment, the residence time is surprisingly reduced and maintained to significantly less than six hours, for example, less than two hours, preferably less than one hour, compared to a conventional residence time of more than eight hours. In particular, it was found quite unexpectedly that such a first extremely short, hot thermal treatment step and such a second, very reduced (significantly shorter than the prior art) hot thermal treatment step substantially preserves the crystal structure of the sodium-containing battery material to be produced, prevents sintering, and does not lead to aggregation.In particular, despite a total residence time of less than six hours, preferably less than one hour, preferably 30 minutes, a high degree of individual crystallinity is maintained at such extremely high temperatures. Due to the extremely short residence time in the first thermal treatment step and the significant reduction in residence time in the second thermal treatment step, the process according to the invention is particularly energy-efficient and cost-optimized. Specifically, the treatment of the sodium-containing battery material in the first reactor within a temperature range of 700°C to 900°C enables the efficient thermal decomposition of many precursor compounds and their conversion into the desired intermediate product (solid sodium-containing battery precursor material). Surprisingly, this leads to improved homogeneity and reactivity of the material.Furthermore, the preferred temperature of 700°C to 900°C in the first reactor for the initial thermal treatment enables a favorable crystal structure and produces an improved particle size without undesirable grain growth or sintering effects. This is particularly advantageous for nano- or microcrystalline materials. This preferred temperature range of 700°C to 900°C also ensures the reliable removal of residual moisture and organic components, thus increasing the purity of the intermediate product. The high temperature of 700°C to 900°C in the first reactor, combined with the very short residence time of 0.1 s to 2 s, allows for a rapid reaction and therefore a high throughput.

[0014] The thermal treatment in the first reactor at temperatures greater than 500°C and less than 1,200°C, especially from 700°C to 900°C, and in the second reactor at temperatures greater than 500°C to 1,200°C, in combination with a short total residence time of greater than 30 minutes to 6 hours, surprisingly offers advantages in terms of complete phase formation already in the first thermal reactor, conversion efficiency, material properties (particle size, crystallinity), reduced sodium losses, purity and process speed, as well as energy efficiency.

[0015] A sodium-containing battery precursor mixture is understood to be, in particular, a starting compound of a mixed metal oxide in solution, slurry, suspension, or solid but moist form, containing sodium. In other words, the sodium-containing battery precursor mixture is thermally treated as the feed material in both the first and second thermal reactors. After the sodium-containing battery precursor mixture is fed into the first thermal reactor, no further or additional material of the same or other materials is added. For example, the sodium-containing battery precursor mixture can be a mixed metal oxide compound containing at least sodium, potassium, and manganese (also called sodium-potassium-manganese oxide or NKMO for short). In particular, the starting compound can have the chemical formula NaaMncCh or NaaKbMncCh, where 0 <a<l, 0<b<l, 0<c<l,5 und a+c > 1 or a+b+c > 1.There are no special restrictions on the form in which the sodium-containing battery precursor mixture is provided, in particular not with regard to the manner in which such a solution, slurry, or suspension may be provided and, in particular, by which method it may be prepared for provision in step a). For example, a suspension may be obtained and provided by low-energy stirring, medium-energy dispersion, or high-energy milling of the starting materials in the suspension medium, such as water.

[0016] For example, the sodium-containing battery precursor mixture has a starting compound according to the chemical formula NaojMnCh or Nao^Ko.oseMnCh.

[0017] The term sodium-containing battery precursor material refers in particular to a mixed metal oxide in solid form, especially powder form.

[0018] Sodium-containing battery material is understood to mean, in particular, a nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material with an average particle size in the range of 10 nm to a few micrometers, especially up to 50 pm. The produced sodium-containing battery material can be used directly as an active battery material, especially as an active cathode material, and is also referred to as a ready-to-use material.

[0019] In step c), the sodium-containing battery material precursor mixture (also called battery precursor compound) is synthesized and dried in a reaction chamber of the first thermal reactor at a temperature of 150°C to 1,200°C, particularly above 500°C and below 1,000°C, preferably from 700°C to 900°C. Step c) is a thermal treatment step and part of the first thermal treatment stage in the first thermal reactor. In step f), the sodium-containing battery precursor material is calcined and converted into the sodium-containing battery material, particularly nano- and / or micro-scale or nano- and / or microcrystalline, in a reaction chamber of the second thermal reactor at a temperature of 500°C to 1,200°C. Step f) is a further thermal treatment step and part of the second thermal treatment stage in the second thermal reactor.

[0020] The first step of the thermal treatment is, in particular, a process in which the sodium-containing battery precursor mixture is synthesized and dried into the solid battery precursor material using the hot gas stream.

[0021] In particular, the sodium-containing battery precursor mixture is thermally treated in the first thermal reactor with a residence time of 0.1 s to 2 s. The first thermal treatment preferably takes place within a short residence time of less than 2 s. This is possible, in particular, due to the finely dispersed direct treatment of the sodium-containing battery precursor mixture in the hot gas stream in the first thermal reactor and the resulting sufficiently high energy input. By reducing the amount of liquid in the battery precursor mixture within the short residence time and at appropriate temperatures, especially in the low range, sintering can be prevented or avoided.

[0022] Drying refers specifically to the drying of the sodium-containing battery precursor mixture, particularly a liquid substance such as a solution, slurry, suspension, or a solid but moist starting material. The first thermal treatment takes place in a flowing hot gas, which causes the starting compound, especially the sodium-containing battery precursor mixture, to be converted into the sodium-containing battery material precursor through synthesis and drying. Surprisingly, it was found that, due to the short residence time and the resulting short reaction time, very fine solid particles with the correct stoichiometry and particle size for the sodium-containing battery precursor material are obtained in solid form in a single step during the conversion through synthesis and / or the drying process in the first thermal reactor.A single step is understood to mean, in particular, the continuous first thermal treatment of the starting compound, especially the sodium-containing battery precursor mixture, and its conversion to the sodium-containing battery material precursor in the hot gas stream of the first thermal reactor, from the introduction of the starting compound, in particular by extremely fine dispersion into the hot gas stream of the first thermal reactor, and thermal treatment of this starting compound by synthesis and / or drying in the hot gas stream with, for example, short residence times of 0.1 s to 2 s in combination with low to high temperatures of 150°C to 1,200°C, until the precipitation of the dried battery material precursor from the first thermal reactor.

[0023] The second step of the thermal treatment is, in particular, a process in which the sodium-containing battery precursor material is synthesized and calcined into active sodium-containing battery material by means of a second thermal reactor, especially a furnace with a hot air atmosphere or a hot gas atmosphere, for example, a nitrogen atmosphere. Surprisingly, this process occurs even at low treatment temperatures of 500°C to 1,200°C, preferably below 1.000°C, preferably in a range of 700°C to 900°C, and for example within a short residence time of 0.5 hours to six hours, preferably less than two hours, and due to the homogeneous and fine-grained structure of the solid-form battery material precursors from the first thermal reactor (= the first thermal treatment stage) a sufficiently high energy input to convert this solid-form sodium-containing battery precursor material into the active solid-form sodium-containing battery material in the second thermal reactor (= second thermal treatment stage).

[0024] Surprisingly, it was discovered that after just thirty minutes of sequential two-stage thermal treatment, in which the moist sodium-containing battery material is dehumidified and, in solid form, first removed from the first thermal reactor and then introduced into the second thermal reactor for further processing, the sodium-containing battery precursor material is completely converted into active sodium-containing battery material. Such a short and complete conversion of sodium-containing battery precursor material, or similar material, with a total residence time of less than six hours, preferably less than two hours, has not been previously mentioned in the literature and is therefore claimed as a significant advancement and indirect evidence of an inventive step.This sequential two-stage handling process with such a short overall residence time enables improved energy efficiency and better control of the thermal treatment conditions in each reactor, resulting in increased phase purity and homogeneity of the final sodium-containing battery material. The separation of the thermal treatment steps also allows for the removal of volatile byproducts and precise adjustment of the reaction parameters, thereby improving the overall quality and performance characteristics of the produced battery material.

[0025] Synthesis and calcination refer specifically to the conversion of the sodium-containing battery material precursor to the sodium-containing battery material, including the formation of the correct crystalline phases. This thermal treatment takes place in the second thermal reactor, which converts the solid-state sodium-containing battery material precursor to the solid-state sodium-containing battery material through synthesis and calcination. Surprisingly, it was found that, due to the homogeneous and finely divided structure of the sodium-containing battery precursor material after the first thermal reactor (step 1 or stage 1), the correct sodium-containing battery material can be obtained in the second thermal reactor with short residence times of 0.5 to 6 hours and relatively low treatment temperatures of 500°C to 900°C.

[0026] In a first possible embodiment, starting with a sodium-containing battery precursor mixture, the conversion to the sodium-containing battery precursor material can be carried out by synthesis and drying in a single step in a hot gas stream in the first thermal reactor, which may be designed, for example, as a spray dryer, pulsation reactor, or the like. This sodium-containing battery precursor material can then be converted to the sodium-containing battery material under moderate conditions in the second thermal reactor, which may be designed, for example, as a furnace, in particular a tunnel furnace, continuous furnace, rotary kiln, or the like.

[0027] The method according to the invention differs significantly from methods known from the prior art in that:

[0028] - the two-stage treatment of sodium-containing material as a sodium-containing battery precursor mixture (in the prior art, sodium is only added after the first step, i.e., after drying and before calcination), in particular without the addition of new or further materials between the two thermal treatment stages and thus without further additives and therefore additive-free,

[0029] - on the one hand, the energy transfer and the conversion process through synthesis and drying by extremely fine dispersion of the starting compound, which is formed as a sodium-containing battery precursor mixture, in the hot gas and its thermal treatment in the hot gas stream with a very short residence time of approximately 0.1 s to 2 s, which allows surprisingly very fine particles to be produced, and

[0030] - on the other hand, the possibility of obtaining the correct active sodium-containing battery material even with short residence times of 0.5 hours to six hours and relatively low treatment temperatures of 500°C to 1,200°C, in particular from 600°C to 1,000°C or 700°C to 900°C, - a very short total residence time or total duration of the thermal treatment of the sodium-containing battery precursor mixture in two separate treatment stages in a range of less than six hours and greater than 30 minutes.

[0031] The advantages achieved with the invention lie particularly in the fact that, compared to conventional methods, the battery material is thermally treated quickly, easily, and in just two steps in an environmentally friendly and energy-efficient manner, specifically through synthesis, drying, and calcination. Furthermore, a higher yield and special properties (such as adjusting the crystallite size, especially homogeneous particle and / or crystallite size distribution, crystal annealing, and reduced sodium losses) are achieved for the thermally treated battery material. In this process, material release into the environment is preferably avoided. Complex precipitation processes (including wastewater and byproducts), grinding, intermediate steps, purification, and lengthy calcination are eliminated.

[0032] In one possible embodiment of step 1, a combustion gas and a fuel are fed into the reactor, particularly into the application chamber, and ignited there. This generates a hot gas stream in which the output compound is introduced into the reactor at a forward injection point, for example, into the application chamber and / or into the reaction chamber near the flow inlet, and is carried and transported by the hot gas stream. The hot gas stream is formed by hot gases produced during combustion. The combustion of the fuel and combustion gases can be flameless or flameless. The hot gas stream can be pulsating, particularly regularly or irregularly pulsating, or uniformly turbulent.

[0033] In a preferred embodiment, the obtained sodium-containing battery precursor material is separated from the hot gas stream at only one separation point, particularly in the outlet region of the first thermal reactor. Specifically, all solid components of the sodium-containing battery precursor material are separated from the hot gas stream at this separation point.

[0034] Preferably, the sodium-containing battery precursor mixture is spray-dried in the first thermal reactor. For this purpose, the first thermal reactor is, for example, designed as a spray dryer. Alternatively, the first thermal reactor can be designed as a pulsation reactor in which the sodium-containing battery precursor mixture is sprayed into the pulsating hot gas stream via a nozzle. Preferably, the hot gas stream in the reaction chamber pulsates or oscillates regularly or irregularly, in particular with a frequency between 5 Hz and 350 Hz. When the first thermal reactor is designed as a pulsation reactor, the thermal treatment is also particularly homogeneous and uniform. The first thermal reactor can also be designed as a fluidized bed reactor. In particular, the battery precursor mixture is introduced into the first thermal reactor by means of a carrier fluid and / or as an aerosol.In combination with the short residence times of less than two seconds in the first thermal reactor, sintering can surprisingly be prevented. For example, the carrier fluid is a gas, particularly ambient air or oxygen, or even an inert gas such as nitrogen. The feedstock can be introduced into the first thermal reactor in the reaction chamber and / or in the combustion chamber of a direct-fired first thermal reactor. The choice of injection point in the first thermal reactor depends on the desired thermal treatment. The choice of injection point, in particular, affects the treatment duration and the temperature exposure.

[0035] In one possible embodiment, the sodium-containing battery precursor material is fed in solid form to the second thermal reactor, which is designed in particular as a furnace, for example as a muffle furnace or rotary kiln or the like.

[0036] Furthermore, it may be provided that the sodium-containing battery material, after thermal treatment in the second thermal reactor, is transferred to a cooling zone and subsequently discharged and separated from the second thermal reactor in solid form, in particular in powder form.

[0037] The sodium-containing battery material can be specifically nickel-free, copper-free, cobalt-free, potassium-free, and / or lithium-free. Alternatively, the sodium-containing battery material can be a sodium material containing nickel, cobalt, manganese, titanium, magnesium, potassium, copper, vanadium, lithium, niobium, aluminum, zirconium, and iron, or an iron phosphate-containing sodium material, a permanganate-containing sodium material, a vanadium phosphate-containing sodium material, or a fluorovanadium phosphate-containing sodium material.

[0038] The obtained and deposited nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material has, in particular, a mean particle size in the range of 10 nm to a few micrometers, especially up to 50 pm. Using the process according to the invention, nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery precursor mixtures and sodium-containing battery precursor materials in solid form can be thermally treated, in particular dried and / or calcined. Such a two-stage thermally treated nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material is particularly suitable for use as an active cathode material.

[0039] The thermal device according to the invention for producing a sodium-containing battery material comprises at least a first thermal reactor, which is configured for the thermal treatment of a sodium-containing battery precursor mixture in a hot gas stream at a temperature of 150°C to 1,200°C and the conversion of this mixture into a solid sodium-containing battery precursor material and for the separation of the solid sodium-containing battery precursor material from the hot gas stream, and a second thermal reactor, which is configured for the thermal treatment and conversion of the solid sodium-containing battery precursor material into the sodium-containing battery material at a temperature of 500°C to 1,200°C and for the separation of the solid sodium-containing battery material.

[0040] The first thermal reactor can, for example, comprise at least a first heating device configured to generate a hot gas stream, and a first thermal treatment chamber adjoining the first heating device, which is configured to thermally treat the sodium-containing battery precursor mixture in the hot gas stream at a temperature of 150°C to 1,200°C, in particular greater than 300°C or 500°C and less than 1,000°C, preferably 700°C to 900°C, as well as a first separation device configured to separate a solid sodium-containing battery precursor material from the hot gas stream.

[0041] The second thermal reactor may, for example, include at least a second heating device designed to heat a second thermal treatment chamber, which in turn is designed for the thermal treatment and conversion of the solid sodium-containing battery precursor material into the sodium-containing battery material in the second thermal treatment chamber at a temperature of 500°C to 1,200°C, and a second separation device designed to separate the solid sodium-containing battery material from the second thermal treatment chamber.

[0042] The first thermal reactor could be, for example, a pulsation reactor, a spray dryer, or a similar type of dryer. The second thermal reactor could be, for example, a rotary kiln, a muffle furnace, a fluidized bed reactor, or the like.

[0043] The invention further provides for the use of the thermal device to carry out the previously described method. Furthermore, the described method can be used to produce active sodium-containing battery material.

[0044] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. These show:

[0045] Figure 1 shows a block diagram of a device for producing particles with a reactor,

[0046] Figures 2 to 4 show different X-ray diffraction analyses (powder X-ray diffraction patterns) for various examples (SEM images after the second process step in the muffle furnace), and

[0047] Figure 5 shows a diagram illustrating the curves of discharge capacities of various

[0048] Half-cells.

[0049] Corresponding parts are marked with the same reference symbols in all figures.

[0050] Figure 1 shows a block diagram of a device V for producing a solid sodium-containing battery material BM, comprising at least a first thermal reactor 1 and a second thermal reactor 2. The first thermal reactor 1 and the second thermal reactor 2 can be coupled to each other in the system, for example via a material line 3. Alternatively, they can be designed as separate units.

[0051] The first thermal reactor 1 can be, for example, a pulsation reactor, a spray dryer, a fluidized bed reactor, or a similar dryer. The second thermal reactor 2 can be, for example, a rotary kiln, a muffle furnace, a fluidized bed reactor, or the like.

[0052] The first thermal reactor 1 is set up to perform a first thermal treatment of a sodium-containing battery precursor mixture BVM and to convert it into a solid sodium-containing battery precursor material fBVM.

[0053] The second thermal reactor 2 is set up to perform a second thermal treatment of the solid sodium-containing battery precursor material fBVM and convert it into the solid sodium-containing battery material BM.

[0054] The first thermal reactor 1 is specifically designed for the thermal treatment of the sodium-containing battery precursor mixture BVM in a hot gas stream 1.1 at a temperature of 150°C to 1,200°C, in particular greater than 300°C or 500°C and less than 1,000°C, preferably 700°C to 900°C, and for converting this into the solid sodium-containing battery precursor material fBVM and for separating the solid sodium-containing battery precursor material fBVM from the hot gas stream 1.1 and from the first thermal reactor 1.

[0055] The second thermal reactor 2 is specifically designed for the thermal treatment and conversion of the solid sodium-containing battery precursor material fBVM from the first thermal reactor 1 into the sodium-containing battery material BM at a temperature of 500°C to 1,200°C, in particular from 600°C to 1,000°C or 700°C to 900°C, and for the separation of the solid sodium-containing battery material BM from the second thermal reactor 2.

[0056] The first thermal reactor 1 can, for example, comprise at least a first heating device 1.2, in particular a burner with a combustion chamber or an electric heater or the like, which is configured to generate the hot gas stream 1.1, and a first thermal treatment chamber 1.3 adjoining the first heating device 1.2, which is configured to thermally treat the sodium-containing battery precursor mixture BVM in the hot gas stream 1.1 at a temperature of 150°C to 1,200°C, in particular from 200°C to 1,000°C or 300°C or 500°C, preferably from 700°C to 900°C, as well as a first separation device 1.4, which is configured to separate the solid sodium-containing battery precursor material fBVM from the hot gas stream 1.1.

[0057] The second thermal reactor 2 can, for example, comprise at least a second heating device 2.1, which is configured to heat a second thermal treatment chamber 2.2, which in turn is configured for the thermal treatment and conversion of the solid sodium-containing battery precursor material fBVM into the sodium-containing battery material BM in the second thermal treatment chamber 2.2 at a temperature of 500°C to 1,200°C, and a second separation device 2.3, which is configured to separate the solid sodium-containing battery material BM from the second thermal treatment chamber 2.2.

[0058] The first thermal reactor 1 is characterized by the thermal treatment of droplets or particles of the at least moist sodium-containing battery precursor mixture BVM or of solid powder in a hot, flowing gas or a hot, flowing and pulsating gas (= hot gas stream 1.1), which simultaneously carries the particles and thus transports them through the first thermal reactor 1, in particular, depending on the feed point, through the first thermal treatment chamber 1.3 (also called application chamber or reaction chamber). Specifically, this first thermal reactor 1 can be a fluidized-flow reactor, a pulsation reactor, a dryer, a calciner, or another suitable system or container for the thermal treatment of the at least moist or solid battery precursor mixture BVM in the hot gas stream 1.1, in particular in the pulsating or oscillating hot gas stream 1.1.The battery precursor mixture (BVM), which is at least moist or solid, is introduced into the first thermal reactor 1, for example, as a starting compound in the form of a suspension, a solution, a slurry, or optionally a moist, solid material. The battery precursor mixture (BVM) can, for example, be introduced into the first heating unit 1.2 and / or the first thermal treatment chamber 1.3.

[0059] In the first thermal reactor 1, particularly in a treatment zone, the battery precursor mixture BVM, carried in the hot gas stream 1.1, is thermally treated at a temperature of 150°C to 1,200°C, particularly above 300°C or 500°C and below 1,000°C, preferably from 700°C to 900°C, with a residence time of 0.1 s to 2 s. During this process, the starting compound, in particular the battery precursor mixture BVM, is converted into the solid battery precursor material fBVM with complete phase formation by synthesis and / or drying, and in particular without sintering, in a single step within the first thermal reactor 1. Such a single-step synthesis and / or drying process for the thermal treatment of the battery precursor mixture BVM is particularly environmentally friendly and resource-efficient. The synthesis and / or drying takes place in direct contact with the hot gas stream 1.1 in a single operation within the first thermal reactor 1.

[0060] The hot gas stream 1.1 is generated by supplying and igniting a fuel and a combustion gas in the first thermal reactor 1. The hot gas stream 1.1 is formed by the hot gases produced during the combustion of the fuel and combustion gases. This combustion can occur, for example, without a flame. Combustion with a flame is also possible. The generated hot gas stream 1.1 can flow in the first thermal reactor 1 in a regular or irregular pulsating manner, or in a uniformly turbulent flow.

[0061] The frequency of the pulsating hot gas flow 1.1 is in the Hertz range, specifically in the range of a few Hertz, for example, greater than 5 Hz, particularly greater than 50 Hz, for example, in the range of 5 Hz to 350 Hz, particularly from 10 Hz to 150 Hz. Parameters of the hot gas flow 1.1, such as amplitude and / or frequency of the oscillation, can be adjusted particularly easily by means of a generator, in particular by means of the first heating device 1.2 and / or a pulsator. Furthermore, this can be achieved via the combustion parameters, such as fuel quantity, air quantity, air temperature, fuel temperature and / or flame temperature, the location of the fuel-air injection, and / or via proportions and / or changes to components of the first thermal reactor 1, in particular the first heating device 1.2 and / or the first treatment chamber 1.3.

[0062] The first thermal treatment chamber 1.3 (also called reaction chamber) can, for example, be designed as a resonance tube. If, for example, a flame from the first heating device 1.2 burns in the first thermal treatment chamber 1.3, then this first thermal treatment chamber 1.3 is also partially designed as a combustion chamber. The combustion chamber is then designed as a combustion space whose dimensions, in particular its diameter, are larger than the dimensions, in particular the diameter, of the wider area of ​​the first thermal treatment chamber 1.3.

[0063] The starting compound of the sodium-containing battery precursor mixture BVM is introduced into the first thermal reactor 1, for example, by means of a carrier fluid and / or as an aerosol, for example in atomized form. The carrier fluid is, for example, a gas, in particular ambient air, oxygen, or nitrogen.

[0064] The battery precursor mixture BVM, in particular in the form of a solution, slurry, suspension, or in a solid state, is introduced into the first thermal reactor 1 and thermally treated there in a treatment zone by means of a pulsating hot gas flow HGS at a temperature of 150°C to 1,000°C, particularly above 300°C or 500°C and below 1,000°C, preferably from 700°C to 900°C, in particular dried and / or calcined. The battery precursor mixture BVM contains sodium and is therefore also referred to as sodium-containing battery precursor mixture BVM. The sodium-containing battery precursor mixture BVM is boron-free, phosphate-free, and carbon-free.

[0065] The sodium-containing battery material BM obtained in powder form is then separated from reactor 1. The solid battery precursor material fBVM obtained from the first thermal treatment is discharged from the first thermal reactor 1.

[0066] To separate the thermally treated solid battery precursor material fBVM as an end product from the hot gas stream 1.1, a suitable first separation device 1.4 is connected to the first thermal treatment chamber 1.3. After the first thermal treatment in a treatment zone within the first thermal treatment chamber 1.3, the solid battery precursor material fBVM can be transferred to a cooling zone of this treatment chamber 1.3 and subsequently discharged and separated in solid form, particularly in powder form, by the first separation device 1.4. The first separation device 1.4 can, for example, be designed as a filter or centrifugal separator.

[0067] The separated solid battery precursor material fBVM is then fed to the second thermal reactor 2 for the second thermal treatment via material line 3 or optionally by other means. No other materials are added.

[0068] The second thermal reactor 2 is set up for the thermal treatment and conversion of the solid sodium-containing battery precursor material fBVM into the sodium-containing battery material BM at a temperature of 500°C to 1,200°C and for the separation of the solid sodium-containing battery material BM from the second thermal reactor 2.

[0069] The solid battery precursor material fBVM can also be introduced into the second thermal reactor 2 as an aerosol and / or by means of a carrier fluid. The solid battery precursor material fBVM is then thermally treated in the second thermal treatment chamber 2.2, in particular a hot oven, at a temperature of 500°C to 1,200°C with a residence time of 0.5 hours to 6 hours and converted to the solid sodium-containing battery material BM, which is separated in solid form, in particular powder form, at the end of the second thermal reactor 2 from the second separator device 2.3. The thermal treatment of the sodium-containing battery precursor mixture BVM via the solid battery precursor material fBVM to the solid sodium-containing battery material BM in the first reactor 1 at temperatures greater than 500°C and less than 1,200°C, in particular from 700°C to 900°C, and in the second reactor 2 at temperatures greater than 500°C to 1.The process takes place at 200°C with a total residence time of more than 30 minutes up to 6 hours. This very short total residence time or treatment time surprisingly offers advantages in terms of complete phase formation already in the first thermal reactor, conversion efficiency, material properties (particle size, crystallinity), reduced sodium losses, purity, process speed, and energy efficiency.

[0070] The primary particle sizes of the battery material BM after the second thermal reactor 2 are of the same order of magnitude as those of the solid battery precursor material fBVM after the first thermal reactor 1 and are, for example, between 100 nm and 50 pm, preferably between 1 pm and 10 pm. Depending on the reactor type, particularly the second thermal reactor 2, these primary particles agglomerate into millimeter-sized spheres, which, however, separate back into the primary particles in the particle size analyzer. It is not entirely clear whether the resulting battery material BM consists of single-crystal or polycrystalline products, as the definition is not unambiguous. Classical precipitation processes preferentially produce polycrystalline products, which would indicate a difference in properties. Under certain conditions, clearly definable single crystals (hexagons in the SEM images) are also likely to form.

[0071] Examples of powders based on manufactured solid sodium-containing battery material BM demonstrate that particularly fine powders can be produced using the previously described two-stage thermal treatment process. Example 1 - Two-stage thermal treatment for the production of a compound, especially one that is potassium-free and lithium-free.

[0072] - Production of the compound NaojMnCh (called NMO for short) in a 2-stage process

[0073] 1. Precursor production (= production of a solid battery precursor material fBVM (also called precursor) in a first thermal reactor designed as a pulsation reactor 1):

[0074] A mixed metal oxide powder with the nominal composition NaOjMnCh, specifically boron-free, phosphate-free, and / or carbon-free, was provided as a sodium-containing battery precursor mixture (BVM). For this purpose, an aqueous solution of manganese(II) nitrate and sodium nitrate in the appropriate stoichiometric ratio and a total product concentration of 20 wt.% (calculated as NaOjMnCh) was fed into a pulsation reactor as the sodium-containing battery precursor mixture (BVM) and reacted in the pulsation reactor to form the solid sodium-containing battery precursor material (fBVM). The aqueous solution of the sodium-containing battery precursor mixture (BVM) was introduced into the combustion chamber of the pulsation reactor at a rate of 20 kg / h via a two-fluid nozzle at a temperature of 800°C. The fuel gas volume was 8 m³. 3 Natural gas / h and combustion air volume 190 m³ 3 / h. The solid battery precursor material fBVM (= product of the first thermal treatment) was separated from the cooled gas stream by filter cassettes as the first separation device 1.4. The chemical analysis (ICP-OES) of the separated material (= separated solid battery precursor material fBVM) yielded 14.1 wt.% sodium and 46.0 wt.% manganese. The product stoichiometry corresponds to the composition set in the battery precursor mixture BVM.

[0075] 2. Post-calcination in the muffle furnace (= production of the solid battery material BM (also called active battery material) in a second thermal reactor 2 designed as a muffle furnace):

[0076] The gray-black powder of solid battery precursor material fBVM obtained from the pulsation reactor (= first thermal reactor 1) was calcined for phase formation in a stationary muffle furnace process in the second thermal reactor 2 (= muffle furnace) under atmospheric air at 700°C, 800°C, and 900°C, specifically at 900°C, for one hour. No additional materials, in particular no additional sodium material, were introduced. The solid battery precursor material fBVM (= powder) deposited from the pulsation reactor was transferred directly into the preheated muffle furnace (= second thermal reactor 2), for example, via material line 3, thus resulting in no additional residence time due to the furnace's heating rate. The total residence time in the apparatus V, with the pulsation reactor as the first thermal reactor 1 and the muffle furnace as the second thermal reactor 2, at the corresponding temperature was therefore one hour.After the appropriate residence time, the calcined material, and thus the solid battery material BM, was transferred to a desiccator or placed outside to prevent absorption of atmospheric moisture. Regardless of the calcination temperature, the solid battery material BM had a specific surface area (BET) of 1 m². 2 / g up to 2 m 2 / g and a mean particle size D50 of 3 pm. The X-ray diffraction analysis for Example 1 (powder X-ray diffractogram and SEM image after the second process step in the muffle furnace), as shown in Figure 2, revealed the presence of beta NaojMnO₄ without any other relevant side phases. The chemical analysis (ICP-OES) of the solid battery material BM calcined at 900°C with the compound NaojMnO₄ (abbreviated NMO) yielded 14.8 wt.% sodium and 50.0 wt.% manganese. The product stoichiometry corresponds to the composition set in the battery material precursor compound (= solid battery precursor material fBVM).

[0077] Example 2 - two-stage thermal treatment for the production of a compound, in particular a lithium-free compound

[0078] Production of the compound Nao,62Ko,os6MnOi (shortened to NKMO) in a 2-stage process

[0079] 1. Precursor production (= production of a solid battery precursor material fBVM (also called precursor) in a first thermal reactor designed as a pulsation reactor): A mixed metal oxide powder with the nominal composition Na0.62Ko,o56MnO2, in particular boron-free, phosphate-free and / or carbon-free, was provided as the sodium-containing battery precursor mixture BVM. For this purpose, an aqueous solution of manganese(II) nitrate, sodium nitrate and potassium nitrate in the corresponding stoichiometric ratio and a total product concentration of 20 wt.% (calculated as Na0.62Ko,o56MnO2) was fed into a pulsation reactor as the sodium-containing battery precursor mixture BVM and reacted in the pulsation reactor to form the solid sodium-containing battery precursor material fBVM. The aqueous solution was introduced into the combustion chamber of the pulsation reactor at a temperature of 800°C via a two-fluid nozzle at a rate of 3 kg / h. The fuel gas volume was 4 m³.3 Natural gas / h and the combustion air volume 43 m³ 3 / h. The solid battery precursor material fBVM (= product of the first thermal treatment) was separated from the cooled gas stream by filter cassettes as the first separation device 1.4. The chemical analysis (ICP-OES) of the separated material (= separated solid battery precursor material fBVM) yielded 12.2 wt.% sodium, 1.5 wt.% potassium, and 46.4 wt.% manganese. The product stoichiometry corresponds to the composition established in the precursor or in the battery precursor mixture BVM.

[0080] 2. Post-calcination in the muffle furnace (= production of the solid battery material BM (also called active battery material) in a second thermal reactor 2 designed as a muffle furnace):

[0081] The gray-black powder obtained from the pulsation reactor (first thermal reactor 1) was calcined for phase formation in a stationary muffle furnace process in the second thermal reactor 2 (muffle furnace) under atmospheric air at 700°C, 800°C, and 900°C, for example at 900°C for one hour. The solid battery precursor material fBVM (powder) separated from the pulsation reactor was transferred directly into the preheated muffle furnace (second thermal reactor 2), for example via material line 3, thus resulting in no additional residence time due to the furnace's heating rate. The total residence time in the apparatus V, with the pulsation reactor as the first thermal reactor 1 and the muffle furnace as the second thermal reactor 2, at the corresponding temperature was therefore one hour.After the appropriate residence time, the calcined material, and thus the solid battery material BM, was transferred to a desiccator or placed outside to prevent absorption of atmospheric moisture. Regardless of the calcination temperature, the solid battery material BM had a specific surface area (BET) of 1–2 m². 2 / g and a mean particle size D50 of 4 pm. The X-ray diffraction analysis for Example 2 (powder X-ray diffractogram and SEM image after the second process step in the muffle furnace), as shown in Figure 3, revealed the presence of beta NaojMnCh and an unidentifiable potassium-containing crystalline phase. The chemical analysis (ICP-OES) of the solid battery material BM calcined at 900°C yielded 13.0 wt.% sodium, 1.2 wt.% potassium, and 50.8 wt.% manganese. The product stoichiometry corresponds to the composition established in the battery material precursor compound (= solid battery precursor material fBVM).

[0082] 3. Electrochemical investigations

[0083] The battery material precursor compound (fBVM), post-calcined at 700°C, 800°C, and 900°C, and its direct use as active cathode material were subsequently investigated electrochemically in half-cell setups (button cells). For this purpose, slurries consisting of 70 wt% cathode active material, 20 wt% conductive carbon black, and 10 wt% PVDF (polyvinylidene fluoride as binder) dissolved in NMP (N-methyl-2-pyrrolidone as solvent) were prepared and used. A 1 molar NaClO4 solution was used as the electrolyte.

[0084] Metallic sodium was used as the anode. At a charge / discharge rate of the IC at 25°C room temperature, consistent specific capacities of approximately 90 mAh / g were obtained for all three materials over 50 cycles, as shown in Figure 5. This demonstrates that even the materials calcined at 700°C contain the electrochemically active phases and can be used as cathode materials. Example 3 - two-stage thermal treatment for the production of a compound that is particularly potassium-free and lithium-free.

[0085] - Production of the compound Nao,7Mno,sFeo,sO2 (NFMO) in a 2-stage process

[0086] 1. Precursor production (= production of a solid battery precursor material fBVM (also called precursor) in a first thermal reactor designed as a pulsation reactor 1):

[0087] A metal oxide powder with the composition Na0.67Mno.5FeO.5O2 was provided as a sodium-containing battery precursor mixture (BVM). For this purpose, an aqueous solution of iron(III) nitrate nonahydrate, sodium nitrate, and manganese(II) nitrate in the corresponding stoichiometric ratio and a total product concentration of 20 wt.% (calculated as Na0.67Mno.5FeO.5O2) was fed into a pulsation reactor as the sodium-containing battery precursor mixture (BVM) and reacted in the pulsation reactor to form the solid sodium-containing battery precursor material (fBVM). The aqueous solution was introduced into the combustion chamber of the pulsation reactor at a rate of 20 kg / h via a two-fluid nozzle at a temperature of 650°C. The fuel gas volume was 5.5 m³. 3 Natural gas / h and the combustion air volume 155 m³ 3 / h. The solid battery precursor material fBVM (= product of the first thermal treatment) was separated from the cooled gas stream by filter cassettes as the first separation device 1.4. The chemical analysis (ICP-OES) of the separated material (= separated solid battery precursor material fBVM) yielded 12.2 wt.% sodium, 17.3 wt.% iron, and 27.1 wt.% manganese. The product stoichiometry shows a lower iron content than was set in the raw material solution and thus in the battery precursor mixture BVM.

[0088] 2. Post-calcination in the muffle furnace (= production of the solid battery material BM (also called active battery material) in a second thermal reactor 2 designed as a muffle furnace):

[0089] The gray-black powder of solid battery precursor material fBVM obtained from the pulsation reactor (first thermal reactor 1) was calcined for one hour in a stationary muffle furnace process in the second thermal reactor 2 (muffle furnace) under atmospheric pressure at 900°C for one hour to achieve phase formation. The solid battery precursor material fBVM (powder) separated from the pulsation reactor was transferred directly into the preheated muffle furnace (second thermal reactor 2), for example, via material line 3, thus eliminating any additional residence time due to the furnace's heating rate. The total residence time in the apparatus V, with the pulsation reactor as the first thermal reactor 1 and the muffle furnace as the second thermal reactor 2, at the corresponding temperature was therefore one hour.After the appropriate residence time, the calcined material, and thus the solid battery material BM, was transferred to a desiccator to prevent absorption of atmospheric moisture. The solid battery material BM had a specific surface area (BET) of 1–2 m². 2 / g and a mean particle size D50 of 10 pm. X-ray diffraction analysis for Example 3, as shown in Figure 4 (powder X-ray diffractogram and SEM image after the second process step in the muffle furnace), revealed the presence of a sodium-iron-manganese oxide phase. Chemical analysis (ICP-OES) of the calcined solid battery material BM yielded 19.2 wt.% iron, 13.5 wt.% sodium, and 30.3 wt.% manganese. The product stoichiometry corresponds to the composition established in the battery material precursor compound (= solid battery precursor material fBVM).

[0090]

[0091] 1 First thermal reactor

[0092] 1.1 Hot gas flow

[0093] 1.2 First heating system

[0094] 1.3 First thermal treatment room

[0095] 1.4 First separation device

[0096] 2 second thermal reactor

[0097] 2.1 Second heating system

[0098] 2.2 Second thermal treatment room

[0099] 2.3 Second separation device

[0100] 3 Material Management

[0101] BVM battery precursor mixture fBVM solid battery precursor material

[0102] BM Battery Material

Claims

P A T E N T A N S P R Ü C H E 1. A process for producing a sodium-containing battery material (BM), comprising the following steps: a) providing a sodium-containing battery precursor mixture (BVM) as a starting compound in the form of a solution, slurry, suspension, or in a solid state; b) introducing the sodium-containing battery precursor mixture (BVM) into a first thermal reactor (1) with a hot gas stream (1.1); c) thermally treating the sodium-containing battery precursor mixture (BVM) carried by the hot gas stream (1.1) at a temperature of 150°C to 1200°C in the first thermal reactor (1); d) extracting the sodium-containing battery precursor material (fBVM) in solid form from the first thermal reactor (1); e) introducing the sodium-containing battery precursor material (fBVM) from step d) into a second thermal reactor (2); f) thermally treating the sodium-containing battery precursor material (fBVM) at a temperature of 500°C to 1.200°C in the second thermal stage. Reactor (2) and conversion of the sodium-containing battery precursor material (fBVM) into the sodium-containing battery material (BM), and g) discharge of the obtained sodium-containing battery material (BM) in solid form from the second thermal reactor (2).

2. Method according to claim 1, wherein the sodium-containing battery precursor mixture (BVM) is thermally treated in the first thermal reactor (1) for a residence time of 0.1 s to 2 s.

3. Method according to claim 1 or 2, wherein the sodium-containing battery precursor mixture (BVM) is spray-dried in the first thermal reactor (1).

4. Method according to any of the preceding claims, wherein the sodium-containing battery precursor mixture (BVM) is introduced into the first thermal reactor (1) by means of a carrier fluid and / or as an aerosol.

5. Method according to one of the preceding claims, wherein the sodium-containing battery precursor material (fBVM) is thermally treated in the second thermal reactor (2) for a residence time of 0.5 hours to 6 hours.

6. Method according to one of the preceding claims, wherein the sodium-containing battery precursor material (fBVM) is thermally treated in the first thermal reactor (1) and in the second thermal reactor (2) for a total residence time of less than 6 hours and greater than 30 minutes.

7. Method according to one of the preceding claims, wherein the sodium-containing battery precursor material (fBVM) is introduced into the second thermal reactor (2) as an aerosol and / or by means of a carrier fluid.

8. Method according to any of the preceding claims, wherein the sodium-containing battery material (BM) is a nickel-free, lithium-free, copper-free and / or cobalt-free sodium-containing battery material (BM).

9. Thermal device (V) for producing a sodium-containing battery material (BM), wherein the device (V) operates according to a method according to any of the preceding claims, comprising at least: - a first thermal reactor (1) for the thermal treatment of a sodium-containing battery precursor mixture (BVM) in a hot gas stream (1.1) at a temperature of 150°C to 1,200°C and for the conversion of this into a solid sodium-containing battery precursor material (fBVM) and for the separation of the solid sodium-containing battery precursor material (fBVM) from the hot gas flow (1.1) is set up, and - a second thermal reactor (2) which is set up for the thermal treatment and conversion of the solid sodium-containing battery precursor material (fBVM) into the sodium-containing battery material (BM) at a temperature of 500°C to 1,200°C and for the separation of the solid sodium-containing battery material (BM).

10. Device (V) according to claim 9, wherein the first thermal reactor (1) is a pulsation reactor or a spray dryer.

11. Device (V) according to claim 9 or 10, wherein the second thermal reactor (2) is a rotary kiln, a muffle furnace or a fluidized bed reactor.

12. Use of a thermal device (V) according to any one of claims 9 to 11 for carrying out the method according to any one of claims 1 to 8.

13. Use of the method according to any one of claims 1 to 8 for the production of nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material (BM).

14. Nano- and / or microscale or nano- and / or microcrystalline sodium-containing battery material (BM), in particular NaaMn c O2 or NaaKbMn cO2, with 0 <a<l, 0<b<l, 0<c<l,5 und a+c > 1 or a+b+c > 1, exhibiting an average particle size in the range of 10 nm to a few micrometers, in particular up to 50 pm.

15. Use of the nano- and / or microscale or nano- and / or microcrystalline battery material (BM) according to claim 14 as a cathode material.

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