Battery recycling equipment and method

Abstract

The present disclosure relates to an apparatus for recycling old batteries, in particular lithium iron phosphate (LFP) batteries, and to a method for recovering valuable materials from old batteries.

Description

Technical Field

[0001] This disclosure relates to an apparatus for recycling used batteries, particularly lithium iron phosphate (LFP) batteries, and to a method for recovering valuable materials from used batteries. Background Art

[0002] Lithium iron phosphate battery materials are a complex mixture of various elements and compounds. For example, many lithium iron battery materials contain valuable metals such as lithium, aluminum, and copper. It may be desirable to recover various elements and compounds from lithium iron battery materials. For example, it may be advantageous to recover lithium and / or copper. Accordingly, there is a need for devices and methods for recycling used batteries.

[0003] DE 10 2015 207 843 A1 discloses a recycling device for used batteries. The batteries are pretreated in a complex manner, particularly discharged and disassembled, and then crushed and dried. This increases the operating costs of the device, particularly due to the labor required.

[0004] CN 111 495 925A discloses a method for pyrolysis, defluorination, and dechlorination of waste lithium batteries. The method includes the following steps: discharging and disassembling the waste lithium batteries; performing primary crushing, drying the crushed product, performing primary separation on the dried crushed product, performing secondary crushing and secondary separation, pyrolyzing, defluorinating, dechlorinating, and in-situ fluorine and chlorine absorption on the separated material, scattering and screening the pyrolysis product to obtain black powder, washing and separating the copper foil and aluminum foil to obtain copper and aluminum products, pyrolyzing and drying the exhaust gas, condensing, dust removing, spraying, adsorbing, and igniting the exhaust gas, and then discharging the exhaust gas. Pyrolysis, defluorination, dechlorination, and in-situ fluorine and chlorine absorption are performed in an airtight rotary kiln. The airtight rotary kiln includes three layers, an inner layer including an absorbent, a middle layer including a pyrolysis material layer, and an outer layer including a heating layer.

[0005] ZHENG, Rujuan et al.: "Optimized Li and Fe recovery from spent lithium-ion batteries via a solution-precipitation method", RSC Advances, Volume 6, Issue 49 (2016), pp. 43613-43625 discloses a method for recovering iron phosphate and lithium carbonate from spent lithium iron phosphate batteries. The method comprises the following steps: (1) after crushing the discharged batteries, the membranes, battery cases and copper contents are recycled, (2) the anode is heat-treated at 600 °C and sieved with a 0.5 mm sieve, (3) the powder is dissolved in 2.5 mol / L sulfuric acid, where L / S is equal to 10, the temperature is 60 °C and the time is 4 hours, (4) iron phosphate is precipitated at a pH of 2 with PEG-600 as a surfactant, (5) sodium carbonate and lithium carbonate are precipitated by concentrating the filtrate and heating it to the boiling point, (6) the recycled iron phosphate and lithium carbonate are mixed with sucrose in a molar ratio of lithium, iron and phosphorus of 1.05:1:1, the mixture is ball-milled and dried, (7) the mixture is pre-sintered under argon at 350 °C and calcined at a temperature of 750 °C for 10 hours to obtain a cathode material.

[0006] EP 3 641 036 A1 relates to a device for recycling old batteries, which device comprises a crushing means for crushing old batteries in a crushing space. The device comprises a drying means arranged downstream of the crushing means for drying the crushed batteries. The device comprises an intermediate storage means arranged between the crushing means and the drying means. The device comprises a stirring tool for keeping the crushed batteries received in the intermediate storage space in motion. The device comprises corresponding supply lines for inert gas for each of the crushing space of the crushing means, the intermediate storage space of the intermediate storage means, and the drying space of the drying means.

[0007] The object of the present disclosure is to provide an improved device for recycling old lithium iron phosphate (LFP) batteries and an improved method for recycling old lithium iron phosphate (LFP) batteries. Summary of the Invention

[0008] There is provided a device for recycling lithium iron phosphate (LFP) battery materials, the device including a comminution device for comminuting LFP battery materials in a comminution space. The device includes a drying device arranged downstream of the comminution device for drying the comminuted LFP battery materials. The device includes an intermediate storage device arranged between the comminution device and the drying device. The volume of the intermediate storage space of the intermediate storage device is at least five times, preferably at least ten times, the volume of the comminution space of the comminution device. The intermediate storage device further includes a stirring tool that is designed and intended to keep the comminuted LFP battery materials received in the intermediate storage space in motion. The device includes a pyrolysis device arranged downstream of the drying device and including a pyrolysis space. In some embodiments, the device includes respective supply lines for an inert gas for each of the comminution space of the comminution device, the intermediate storage space of the intermediate storage device, the drying space of the drying device, and the pyrolysis space of the pyrolysis device.

[0009] There is also provided a method for recycling LFP battery materials. The method includes: providing LFP battery materials to a comminution device; comminuting the LFP battery materials in the comminution device; transferring the comminuted LFP battery materials to a drying device; drying the comminuted LFP battery materials; transferring the comminuted and dried LFP battery materials to a pyrolysis device; heating the comminuted and dried LFP battery materials to a temperature of 400 °C to 630 °C while bringing the comminuted and dried LFP battery materials into contact with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the comminuted and dried LFP battery materials to obtain pyrolyzed battery materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic view of an exemplary recycling device according to the present disclosure.

[0011] DEFINITIONS

[0012] In the present disclosure, the term "battery" covers not only non-rechargeable primary battery cells, but also accumulators, i.e., rechargeable energy storage battery cells. In particular, the devices of the present disclosure are suitable for processing rechargeable and non-rechargeable energy storage battery cells that contain lithium, in particular lithium compounds and / or lithium ions, and are very commonly referred to as "LFP batteries" in the present application.

[0013] Furthermore, in the present disclosure, the term "drying" is also used to remove (in particular evaporate) electrolytes such as dimethyl carbonate (DMC), diethyl carbonate (DEC), and / or ethyl methyl carbonate (EMC). Although the term "drying" is related not only to the removal of liquid substances, but may also be related to the removal of solids, it has become common in the technical language used for this purpose.

[0014] Detailed description

[0015] There is provided a device for recycling LFP battery materials, the device including a comminution device for comminuting LFP battery materials in a comminution space. The device includes a drying device arranged downstream of the comminution device for drying the comminuted LFP battery materials.

[0016] The device includes an intermediate storage device arranged between the comminution device and the drying device. The volume of the intermediate storage space of the intermediate storage device is at least five times, preferably at least ten times, the volume of the comminution space of the comminution device. The intermediate storage device further includes a stirring tool which is designed and intended to keep the comminuted LFP battery materials received in the intermediate storage space in motion. The intermediate storage device assumes a plurality of functions in the device according to the present disclosure.

[0017] First, the intermediate storage allows the electrochemical reactions occurring in the comminuted material to weaken to such an extent that they do not cause problems when the comminuted material is supplied to the drying device.

[0018] Furthermore, the intermediate storage device serves as a temporary reservoir for the comminuted material. In this way, the device according to the present disclosure can be operated in a batch mode, such that in each batch only a small amount of LFP battery materials needs to be supplied to the comminution device, while a larger amount of comminuted material can be supplied to the drying device in one go. Since the amount of material to be comminuted in one step is small, the risk of spontaneous combustion can actually be excluded. This is particularly advantageous because the old LFP batteries supplied to the comminution device in the device according to the present disclosure may not have been pre-discharged or at least not fully pre-discharged, and the residual charge driving the electrochemical reaction of the LFP batteries is unknown.

[0019] And finally, the freshly comminuted LFP battery materials entering the intermediate storage space from the comminution device are mixed by the stirring tool with the comminuted material previously introduced into the intermediate storage space (in which the electrochemical reaction has at least partially weakened). This helps to avoid the formation of local volumes with inadmissible high temperatures and an increased risk of spontaneous combustion.

[0020] To further reduce the risk of spontaneous combustion, an inert gas is additionally supplied to the comminution device and the intermediate storage device and the drying device, i.e., a gas that at least hinders (if not even prevents) the spontaneous combustion of the comminuted batteries during the electrochemical reaction. For example, nitrogen and / or carbon dioxide gas can be used as the inert gas.

[0021] All these measures ensure that in the device according to the present disclosure, substantially unprepared LFP batteries, in particular LFP batteries that have not been or at least not fully pre-discharged and disassembled, can be recycled in a substantially automated and thus cost-effective process.

[0022] In an exemplary device, 1 ton of LFP battery material can be recycled per hour. The LFP battery material is supplied to the crushing device in the form of ten batches of 100 kg each and is temporarily stored in an intermediate storage device before being conveyed to the drying device. In one embodiment, the volume of the crushing space of the crushing device is approximately 0.5 m 3 , and / or the volume of the intermediate storage space of the intermediate storage device is approximately 6.0 m 3 , and / or the volume of the drying space of the drying device is approximately 3.0 m 3 . It must be considered that the crushed material is compacted by a conveying device (such as a pipe screw conveyor) that conveys the material from the homogenizing device to the drying device.

[0023] In order to prevent environmentally incompatible or even dangerous gases from escaping from the battery recycling device, in another embodiment of the device, it is proposed that the crushing space and / or the intermediate storage space and / or the drying space are airtight.

[0024] In another embodiment, the transfer device for transferring the crushed LFP battery material from the crushing device to the intermediate storage device and / or the transfer device for transferring the crushed LFP battery material from the intermediate storage device to the drying device are airtight and are connected to the adjacent devices in an airtight manner.

[0025] In another embodiment, an exhaust gas treatment device is provided, which is connected to the crushing space and / or the intermediate storage space and / or the drying space via a gas supply pipeline and is configured to treat the gases formed in the crushing space and / or in the intermediate storage space and / or in the drying space. Those skilled in the art are familiar with the components that the exhaust gas treatment device may or should include depending on the gas components generated. For this reason, a detailed discussion of the design and function of the exhaust gas treatment device can be omitted at this point.

[0026] In order to further reduce the risk from the recycling device, in another embodiment of the device, a cryogenic freezing device is arranged upstream of the crushing device. The cryogenic freezing device includes a feed pipeline for a liquid cryogenic medium and is configured to cryogenically freeze old batteries in the liquid cryogenic medium before crushing them in the crushing device.

[0027] Liquefied inert gases, especially liquid nitrogen and / or liquid carbon dioxide, can be used as the liquid cryogenic medium. In this case, the gas headspace of the cryogenic freezing device can also be connected to a supply pipeline for inert gas. In this way, the cryogenic medium evaporated due to the energy input from the old LFP battery material can be used as an inert gas in the crushing device and / or the intermediate storage device and / or the drying device.

[0028] In order to prevent the oversize pieces of the crushed LFP battery material from leaving the crushing device in the direction of the intermediate storage device, in another embodiment of the device, a sieve unit, such as a perforated sieve, is arranged at the outlet of the crushing device. In one embodiment, the openings of the sieve unit have a diameter of 20 mm. For example, a universal shredder of type NGU 0513 sold by BHS Sonthofen GmbH of Germany can be used as the crushing device.

[0029] In order to ensure that the temperature in the intermediate storage space does not exceed a critical temperature value (e.g., 120 °C), in some embodiments of the device, a cooling device is assigned to the intermediate storage device. In some embodiments, the cooling device takes the form of cooling tubes attached to the wall surrounding the intermediate storage space, these cooling tubes being in thermal exchange contact with the wall, and if necessary, a cooling medium can flow through these cooling tubes.

[0030] In another embodiment, the drying device is a negative pressure drying device and has a pressure control unit that maintains the pressure in the drying space at a value of approximately 50 hPa. In another embodiment, the drying device has a temperature control unit that maintains the temperature in the drying space at a value of approximately 100 °C to approximately 120 °C.

[0031] The pyrolysis device is arranged downstream of the drying device. The pyrolysis device is configured to receive the crushed and dried LFP battery material from the drying device and subject it to heat treatment in the pyrolysis space provided within the pyrolysis device. In some embodiments, the pyrolysis device includes a supply line for supplying an inert gas and / or a reducing gas to the pyrolysis space of the pyrolysis device. In some embodiments of the device, the pyrolysis device includes an oven, such as an electric oven.

[0032] In some embodiments of the device, the pyrolysis device includes a rotary kiln. The rotary kiln is a cylindrical container that is slightly inclined to the horizontal plane and slowly rotates about its longitudinal axis. The process feedstock is fed into the upper end of the cylinder. As the kiln rotates, the material gradually moves downward towards the lower end and may undergo a certain amount of agitation and mixing.

[0033] In some embodiments of the device, the kiln has a length in the range of 12 to 18 m. In some embodiments of the device, the kiln has a length in the range of 15 to 17 m. The kiln length refers to the length of the heating zone of the kiln. Additional elements will make the entire kiln slightly longer. In some embodiments of the device, the inner diameter of the cylindrical tube is in the range of 1.5 m to 2.1 m, such as 1.7 m to 1.9 m.

[0034] In some embodiments of the device, the rotary kiln is characterized by external heating elements that use electricity. In some embodiments, the kiln includes a plurality of heating zones. In some embodiments, each heating zone is configured to operate at a temperature in the range of 400°C to 650°C, such as 520°C to 600°C. In some embodiments, thermoelectric elements are provided in each heating zone for measuring the temperature in the corresponding zone. In one embodiment, each heating zone has a length of 0.5 m to 6 m, such as 1 m to 4 m, such as 1.5 m to 3 m.

[0035] In some embodiments of the device, the kiln is connected at its lower end to a material discharge hood and a duct for the exhaust gas, and is characterized by being hermetically sealed at both ends of the kiln. Mounting equipment is provided to eliminate hydrocarbons from the exhaust gas stream of the kiln before discharging the exhaust to the atmosphere.

[0036] The oxidation device is arranged downstream of the pyrolysis device. The oxidation device is configured to receive the pyrolyzed LFP battery material from the pyrolysis device and subject it to oxidative roasting in an oxidation space provided within the oxidation device to produce oxidized LFP battery material. In some embodiments, the oxidation device includes a supply line for supplying an oxygen-containing gas to the oxidation space of the oxidation device. In some embodiments of the device, the oxidation device includes an oven, such as a furnace or a kiln.

[0037] In some embodiments of the device, the pyrolysis device includes at least one rotary kiln. In some embodiments of the device, the rotary kiln is a directly heated kiln that includes at least one burner arranged inside the kiln.

[0038] In some embodiments of the device, the filling device is arranged downstream of the oxidation device. The filling device provides the oxidized LFP battery material for further processing. In some embodiments, in the filling device, the oxidized LFP battery material is filled into a transport container.

[0039] In some embodiments, at least one screening device (preferably arranged upstream of the filling device) is arranged downstream of the pulverizing device. In this screening device, the components of the pulverized and dried LFP battery can be separated from each other and thus supplied for more targeted processing. In some embodiments, at least one screening device (preferably arranged upstream of the filling device) is arranged downstream of the oxidation device. In this screening device, the material obtained from the oxidation device can be separated into fractions with different particle sizes, and these fractions can be supplied for more targeted downstream processing. In some embodiments, at least one screening device is arranged upstream of the pyrolysis device, and at least one screening device is arranged downstream of the oxidation device.

[0040] This disclosure also provides a method for recycling LFP battery materials. The method includes:

[0041] a) Provide an LFP battery material to a crushing device,

[0042] b) Crush the LFP battery material in the crushing device,

[0043] c) Transfer the crushed LFP battery material to a drying device,

[0044] d) Dry the crushed LFP battery material,

[0045] e) Transfer the crushed and dried LFP battery material to a pyrolysis device,

[0046] f) While contacting the crushed and dried LFP battery material with an inert gas and with a reducing gas in-situ generated by the thermal decomposition of the crushed and dried LFP battery material, heat the crushed and dried LFP battery material to a temperature in the range of 400 °C to 630 °C to obtain a pyrolyzed LFP battery material;

[0047] g) While contacting the pyrolyzed LFP battery material with an oxygen-containing gas, oxidize the pyrolyzed LFP battery material at a temperature in the range of 400 °C to 600 °C, such as 450 °C to 550 °C, such as 470 °C to 530 °C, to obtain an oxidized LFP battery material.

[0048] At the start of the process, an old LFP battery material is provided to the crushing device and then crushed in the crushing device.

[0049] In some embodiments of the method, the LFP battery material is at least one selected from the following: lithium iron phosphate batteries, lithium iron phosphate battery waste, lithium iron phosphate battery production waste, lithium iron phosphate battery cell production waste, lithium iron phosphate cathode active materials, and combinations thereof.

[0050] The lithium iron phosphate battery can be disassembled, stamped, milled (e.g., in a hammer mill, a rotary mill), and / or shredded (e.g., in an industrial shredder). The active material of the battery electrode can be obtained through such mechanical treatment. The light fractions (such as the housing parts made of organic plastics and aluminum foil or copper foil) can be removed, for example, by forced air flow, air separation, or classification or screening.

[0051] The battery waste can originate from, for example, old LFP batteries or production waste such as defective materials. In some embodiments, the material is obtained from mechanically treated LFP battery waste, for example, from LFP battery waste treated in a hammer mill, a rotary mill, or an industrial shredder.

[0052] A relatively large portion of the LFP battery waste, such as the housing, wiring, and electrode carrier film, can be mechanically separated so that the corresponding materials can be excluded from the used LFP batteries employed in the method disclosed herein. In some embodiments, the separation is accomplished by manual or automatic sorting. For example, magnetic parts can be separated by magnetic separation; non-magnetic metals can be separated by eddy current separators. Other techniques can include jigs and air tables.

[0053] In some embodiments of the method, step b) comprises the following steps:

[0054] I. Feed the material to a first comminution device and comminute the material to obtain first particles having a maximum diameter of 50 mm or less;

[0055] II. Feed the first particles obtained in step I) to a second comminution device and comminute the first particles to obtain second particles having a maximum diameter of 20 mm or less;

[0056] III. Feed the second particles obtained in step II) to a first separation device to remove a first fine fraction consisting of particles having a size of <500 μm from the second particles;

[0057] IV. Feed the second particles obtained in step III) to a third comminution device and comminute the second particles to generate a second fine fraction consisting of particles having a size of <500 μm;

[0058] V. Combine the first fine fraction and the second fine fraction.

[0059] The first and second fine fractions respectively consist of particles having a size of <500 μm. In other words, all the particles of the first and second fine fractions respectively pass through a sieve having a mesh width of 500 μm.

[0060] In some embodiments, step V. involves screening the first fine fraction and the second fine fraction through a sieve having a mesh width of no more than 500 μm (e.g., 250 μm or less). In some embodiments, the particles remaining on the sieve are washed with water to remove the residual fine fraction adhering to the particles remaining on the sieve.

[0061] Transfer the comminuted LFP battery material to a drying device and dry it. In some embodiments of the method, the comminuted and dried LFP battery material includes aluminum foil and cathode active material.

[0062] In some embodiments, the comminuted and dried LFP battery material contains copper, aluminum, lithium, iron, phosphorus, or a combination thereof.

[0063] In some embodiments, the crushed and dried LFP battery material contains 1 to 50 wt.-%, such as 20 to 45 wt.-%, such as 30 to 40 wt.-% of carbon, based on the total weight of the crushed and dried LFP battery material.

[0064] In some embodiments, the crushed and dried LFP battery material contains 0.1 to 10 wt.-%, such as 1 to 7 wt.-%, such as 2 to 4 wt.-% of aluminum, based on the total weight of the crushed and dried LFP battery material.

[0065] In some embodiments, the crushed and dried LFP battery material contains 0.5 to 7 wt.-%, such as 1 to 5 wt.-%, such as 1.5 to 3 wt.-% of copper, based on the total weight of the crushed and dried LFP battery material.

[0066] In some embodiments, the crushed and dried LFP battery material contains 0 to 11 wt.-%, such as 1 to 7 wt.-%, such as 2 to 5 wt.-% of manganese, based on the total weight of the crushed and dried LFP battery material.

[0067] In some embodiments, the crushed and dried LFP battery material contains 1 to 7 wt.-%, such as 1.5 to 5 wt.-%, such as 2 to 4 wt.-% of lithium, based on the total weight of the crushed and dried LFP battery material.

[0068] In some embodiments, the crushed and dried LFP battery material contains 10 to 35 wt.-%, such as 12.5 to 25 wt.-%, such as 15 to 20 wt.-% of iron, based on the total weight of the crushed and dried LFP battery material.

[0069] In some embodiments, the crushed and dried LFP battery material contains 1 to 7 wt.-%, such as 1.5 to 5.5 wt.-%, such as 2 to 4 wt.-% of fluorine, based on the total weight of the crushed and dried LFP battery material.

[0070] In some embodiments, the crushed and dried LFP battery material contains 5 to 20 wt.-%, such as 7 to 16 wt.-%, such as 9 to 12 wt.-% of phosphorus, based on the total weight of the crushed and dried LFP battery material.

[0071] The sum of the weight fractions of C, Al, Cu, Mn, Li, Fe, P, and F in the crushed and dried LFP battery material is less than or equal to 100 wt.-%.

[0072] Transfer the crushed and dried LFP battery material to a pyrolysis device and then heat it to a temperature of 400 °C to 630 °C while bringing the crushed and dried LFP battery material into contact with an inert gas and a reducing gas in-situ generated by the thermal decomposition of the crushed and dried LFP battery to obtain a pyrolyzed LFP battery material.

[0073] In some embodiments, the method of the present disclosure includes providing a crushed and dried LFP battery material at a first temperature; heating the crushed and dried LFP battery material at a second temperature in the range of 400 °C to 630 °C, such as 520 °C to 630 °C, such as 550 °C to 600 °C; bringing the crushed and dried LFP battery material into contact with an inert gas and a reducing gas in-situ generated by the thermal decomposition of the crushed and dried LFP battery material to obtain a pyrolyzed LFP battery material; oxidizing the pyrolyzed LFP battery material at a temperature in the range of 400 °C to 600 °C, such as 450 °C to 550 °C, to obtain an oxidized LFP battery material, and optionally cooling the oxidized LFP battery material to a third temperature in the range of 10 °C to 100 °C, such as 20 °C to 70 °C.

[0074] In some embodiments, the method of the present disclosure includes providing a crushed and dried LFP battery material at a first temperature. In some embodiments of the method, the first temperature ranges from -50 °C to 50 °C, for example, -10 °C to 40 °C, for example, 0 °C to 30 °C. In a specific embodiment, the first temperature is the ambient temperature.

[0075] In some embodiments of the method, calcium carbonate is added to the crushed and dried LFP battery material before transferring the crushed and dried LFP battery material to a heat treatment device. In some embodiments, calcium carbonate is added in a stoichiometric amount relative to the total fluorine content of the crushed and dried LFP battery material. For every mol of fluorine present, 0.5 mol of calcium carbonate is added. During the heat treatment of the crushed and dried LFP battery material, calcium carbonate reacts with the fluorine present in the crushed LFP battery material, thereby capturing the fluorine and preventing the formation of corrosive and toxic gases (such as hydrogen fluoride).

[0076] In some embodiments of the method, a mixture of calcium carbonate and magnesium carbonate is added to the crushed and dried LFP battery material before transferring the crushed and dried LFP battery material to a heat treatment device. In some embodiments, a calcium carbonate / magnesium carbonate mixture is added in a stoichiometric amount relative to the total fluorine content of the crushed and dried LFP battery material. For every mol of fluorine present, the total molar amount of calcium carbonate and magnesium carbonate added is 0.5 mol (x mol CaCO 3 + y mol MgCO 3= 0.5 mol (CaCO 3 + MgCO 3 ))。In some embodiments, before transferring the pulverized and dried LFP battery material to the heat treatment device, dolomite (CaMg(CO 3 )) 2 ) is added to the pulverized and dried LFP battery material. During the heat treatment of the pulverized and dried LFP battery material, the calcium carbonate / magnesium carbonate mixture reacts with the fluorine present in the pulverized and dried LFP battery material, thereby capturing the fluorine and preventing the formation of corrosive and toxic gases (such as hydrogen fluoride). It has been found that using a mixture of calcium carbonate and magnesium carbonate further improves the leaching efficiency of lithium and reduces the amount of iron in the leaching solution.

[0077] In some embodiments, the method disclosed herein includes heating the pulverized and dried LFP battery material at a second temperature in the range of 400 °C to 630 °C, such as 520 °C to 630 °C. In some embodiments of the method, the second temperature ranges from 530 °C to 600 °C. In further embodiments, the second temperature ranges from 550 °C to 580 °C.

[0078] In some embodiments of the method, the heating step includes a temperature ramp from the first temperature to the second temperature over a period of 10 minutes to 2 hours. In some embodiments of the method, the heating step includes a temperature ramp from the first temperature to the second temperature over a period of 30 minutes to 1 hour.

[0079] In some embodiments, the temperature ramp has an average rate of temperature increase of at least 5 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 10 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 15 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 20 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 25 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase as high as 50 K per minute.

[0080] In some embodiments, the temperature ramp has an average rate of temperature increase in the range of 5 K per minute to 50 K per minute. In some embodiments, the temperature ramp has an average rate of temperature increase in the range of 10 K per minute to 50 K per minute.

[0081] In some embodiments of the method, the heating step includes a dwell at the second temperature for a period ranging from 0 minutes to 1 hour, such as 10 minutes to 45 minutes, or 15 minutes to 30 minutes.

[0082] In some embodiments of the method, the heating step includes dwelling at one or more intermediate temperatures in a range from a first temperature to a second temperature.

[0083] In some embodiments, the method of the present disclosure includes: providing a comminuted and dried LFP battery material at a first temperature in a range from -50 °C to 50 °C; heating the comminuted and dried LFP battery material at a second temperature in a range from 520 °C to 600 °C; wherein the heating step includes a temperature ramp from the first temperature to the second temperature over a period of time in a range from 10 minutes to 1 hour; dwelling at the second temperature for a time in a range from 0 minutes to 1 hour; and optionally, cooling the material to a third temperature in a range from 50 °C to 70 °C.

[0084] The method of the present disclosure includes contacting a comminuted and dried LFP battery material with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the comminuted and dried LFP battery material to obtain a pyrolyzed LFP battery material.

[0085] In some embodiments, the flow rate of the inert gas is in the range of 100 to 300 Sm 3 / h, such as 150 to 250 Sm 3 , for example 200 Sm 3 / h (standard cubic meters per hour).

[0086] In some embodiments, the inert gas comprises at least one gas selected from the group consisting of argon (Ar), nitrogen (N 2 ), helium (He), and mixtures thereof.

[0087] In some embodiments, the reducing gas comprises at least one gas selected from the group consisting of hydrocarbons, hydrogen (H 2 ), carbon monoxide (CO), and mixtures thereof.

[0088] In some embodiments of the method, the reducing gas comprises: 5 vol% to 70 vol% of C 1 to C 10 hydrocarbons, 5 vol% to 95 vol% of carbon dioxide (CO 2 ), 0.1 vol% to 10 vol% of carbon monoxide (CO), and 0.1 vol% to 15 vol% of H 2 ; wherein each vol% is based on the total volume of the reducing gas, and the vol% of C 1 to C 10 hydrocarbons plus the vol% of CO 2 plus the vol% of H 2 is less than or equal to 100%.

[0089] In some embodiments of the method, the reducing gas comprises: 5 vol% to 70 vol% of C1 to C 10 hydrocarbons, 5 vol% to 45 vol% of C 1 to C 10 oxohydrocarbons, and 0.1 vol% to 15 vol% of H 2 ; where each vol% is based on the total volume of the reducing gas, and the vol% of C 1 to C 10 hydrocarbons plus the vol% of C 1 to C 10 oxohydrocarbons plus the vol% of H 2 is less than or equal to 100%.

[0090] In some embodiments of the method, the heating step is carried out in a rotary kiln. In some embodiments of the method, the kiln is filled with 5% to 20%, such as 7% to 16%, such as 9% to 12% of the total volume of the kiln of crushed and dried LFP battery material.

[0091] In some embodiments of the method, at least one screw conveyor is used to feed the crushed and dried LFP battery material into the kiln.

[0092] In some embodiments of the method, the kiln rotates at 0.5 rpm to 3 rpm. In some embodiments of the method, the kiln rotates at 1.4 rpm to 2.6 rpm. In some embodiments of the method, the kiln rotates at 1.8 rpm to 2.2 rpm.

[0093] In some embodiments of the method, an overpressure is maintained in the kiln during operation to prevent air from entering the kiln.

[0094] In some embodiments of the method, hot gas passes through the kiln in the same direction as the process material (cocurrent). In some embodiments of the method, the crushed and dried LFP battery material and an inert gas are fed into the rotary kiln in cocurrent flow. Cocurrent flow ensures that no dust escapes from the upper end of the kiln.

[0095] In some embodiments of the method, the rotary kiln is heated by external heating elements using electricity. In some embodiments of the method, the kiln includes a number of heating zones. In some embodiments of the method, each heating zone operates at a temperature in the range of 400 °C to 630 °C, such as 520 °C to 600 °C.

[0096] The pyrolyzed LFP battery material is transferred to an oxidation device and then heated at a temperature in the range of 400 °C to 600 °C, such as 450 °C to 550 °C, such as 470 °C to 530 °C, while contacting the pyrolyzed battery material with an oxygen-containing gas to obtain an oxidized LFP battery material.

[0097] In some embodiments, the pyrolyzed LFP battery material is directly transferred from the outlet of the pyrolysis device to the inlet of the oxidation device, such that the temperature of the pyrolyzed battery material does not decrease significantly, for example, by no more than 150 K, for example, by no more than 100 K.

[0098] In the oxidation device, the pyrolyzed LFP battery material is heated at a temperature in the range of 400 °C to 600 °C, for example, 450 °C to 550 °C, for example, 470 °C to 530 °C. In some embodiments of the method, the oxidation step includes a residence time at this temperature in the range of 0 minutes to 2 hours, for example, 10 minutes to 90 minutes, or 15 minutes to 45 minutes.

[0099] During the treatment in the oxidation device, the pyrolyzed LFP battery material is contacted with an oxygen-containing gas. In some embodiments of the method, the oxygen-containing gas is air. In some embodiments of the method, the oxygen-containing gas is lean oxygen air, i.e., a mixture of nitrogen and oxygen having an oxygen content of less than 20.95 vol%. In some embodiments of the method, lean oxygen air having an oxygen content of less than 8 vol%, for example, less than 5 vol%, for example, 1 to 3 vol% is used. In some embodiments of the method, the oxygen-containing gas has an oxygen content of more than 21 vol%.

[0100] In some embodiments, the flow rate of the oxygen-containing gas is in the range of 200 to 3000 Sm 3 / h, for example, 700 to 900 Sm 3 / h, or 2000 to 2500 Sm 3 / h (standard cubic meters per hour).

[0101] In some embodiments, the oxidized LFP battery material contains Li 3 Fe 2 (PO 4 ) 3 and Fe 2 O 3 .

[0102] In some embodiments, the method of the present disclosure involves cooling the obtained oxidized LFP battery material to a third temperature in the range of 10 °C to 100 °C, for example, 20 °C to 50 °C. In some embodiments, the cooling is carried out in a rotary cooler located at the lower end of the rotary kiln. In some embodiments, the rotary cooler has the same diameter as the rotary kiln and is cooled by a water jacket.

[0103] As provided herein, different process parameters can produce oxidized LFP battery materials having different compositions and / or properties. Oxidized LFP battery materials having, for example, favorable compositions, mechanical properties, surface hydrophilicity, and / or porosity can, for example, result in improved processability and / or recyclability in subsequent downstream processing steps.

[0104] This disclosure also provides the use of the oxidized LFP battery materials of this disclosure in the recovery of valuable materials from spent LFP batteries. In some embodiments, the oxidized LFP battery materials are used as intermediates in downstream leaching processes.

[0105] For example, the oxidized LFP battery materials can be leached with an acidic aqueous solution containing, for example, sulfuric acid (H 2 SO 4 ) to obtain a solution containing one or more valuable metal ions. The solution containing one or more valuable metal ions can be further purified via, for example, solvent exchange, ion exchange, precipitation, extraction, and / or electrolysis.

[0106] Without wishing to be bound by theory, it is believed that the oxidized LFP battery materials have beneficial properties for improving one or more downstream processes, such as leaching. For example, it is believed that the brittleness of the oxidized LFP battery materials can result in smaller particles, which have a more beneficial surface area to volume ratio, thereby facilitating dissolution during acid leaching. Additionally, the smaller particle size can facilitate subsequent transport steps, such as conveyance.

[0107] Examples

[0108] The present disclosure will be explained in more detail below based on embodiments with reference to the accompanying drawings.

[0109] Figure 1 is a schematic diagram of an embodiment of an apparatus for recycling LFP battery materials of this disclosure. The apparatus for recycling LFP battery materials is denoted by reference numeral 100. Apparatus 100 includes a pulverizing device 120, an intermediate storage device 130, a drying device 140, a pyrolysis device 150, and an oxidation device 170.

[0110] Apparatus 100 is designed for batch operation. In other words, a predetermined amount of LFP battery materials (e.g., 100 kg of spent LFP batteries) is supplied to pulverizing device 120 via an upstream metering feeder 110, which is used to divide the delivered spent LFP battery materials into predetermined separate portions.

[0111] The comminution device 120 may be equipped with a sieve device 122 on the outlet side, for example a perforated plate with holes having a diameter of approximately 20 mm. In order to prevent environmentally incompatible gases from escaping from the comminution device 120, the device is preferably airtight. In addition, the comminution device 120 may be equipped with a supply line 124 for an inert gas, via which the inert gas can be supplied to the comminution space 120a of the comminution device 120, which reduces (if not completely eliminates) the risk of spontaneous combustion of the comminuted LFP battery material.

[0112] After a predetermined residence time in the comminution device 120, the comminuted battery is conveyed to an intermediate storage device 130. This intermediate storage device 130 is also preferably airtight. In addition, an inert gas can also be supplied to the intermediate storage device 130 via a feed line 132 in order to be able to reduce (if not completely eliminate) the risk of spontaneous combustion of the comminuted battery. The intermediate storage device 130 also has a stirring tool 134, which continuously mixes the received and comminuted battery in the intermediate storage space 130a in order to prevent the formation of local volumes with too high a temperature. In the case where the temperature in the intermediate storage space 130a rises too much, the intermediate storage device 130 also has a cooling device 136 (for example a cooling coil) through which a cooling medium flows, which is attached to and in thermal exchange contact with the outer boundary wall of the intermediate storage space 130a.

[0113] After the comminuted LFP battery material from a predetermined number of comminution processes has been received in the intermediate storage device 130, the intermediate storage space 130a is emptied in the direction of a drying device 140, the drying space 140a of which is preferably also airtight and which may also include a stirring tool 144. In addition, an inert gas can also be supplied to the drying space 140a via a line 146.

[0114] In the illustrated embodiment, the drying device 140 is a negative pressure drying device, which dries the comminuted LFP battery material at a pressure of 50 hPa and at a temperature of at least 120 °C. The pressure control and temperature control unit required for this purpose is Figure 1 denoted by the reference numeral 148 in

[0115] After the comminuted battery has been dried in the drying device 140, the drying space 140a is emptied in the direction of a pyrolysis device 150.

[0116] The screening device 160 can be arranged downstream of the drying device 140, in which the components of the comminuted and dried LFP battery material can be separated from one another and thus be supplied for more targeted processing. In principle, a plurality of screening stages can be arranged one after the other. In some embodiments, one of the screening stages comprises a simple sieve.

[0117] The pyrolysis device 150 receives the comminuted, dried and optionally screened LFP battery material in a pyrolysis space 150a, in which they are subjected to a heat treatment under reducing conditions to obtain pyrolyzed LFP battery material. An inert gas can also be supplied to the pyrolysis space 150a via line 152.

[0118] The oxidation device 170 receives the pyrolyzed LFP battery material in an oxidation space 170a, in which it is subjected to a heat treatment under oxidation conditions to obtain oxidized LFP battery material. An oxygen-containing gas can be supplied to the oxidation space 170a via line 172.

[0119] The screening device 160 can be arranged downstream of the oxidation device 170, in which the components of the oxidized LFP battery material can be separated from one another and thus be supplied for more targeted processing. In principle, a plurality of screening stages can be arranged one after the other. In some embodiments, one of the screening stages comprises a sieve. In some embodiments, the sieve is a vibrating sieve or a vibrating screen mesh.

[0120] Finally, the oxidized LFP battery material can be filled into a transport container 182 in a filling device 180.

[0121] It should also be noted that not only can the comminution device 120, the intermediate storage device 130, the drying device 140, and the pyrolysis device 150 be made airtight, but also the transfer devices for transferring the comminuted battery from the comminution device 120 to the intermediate storage device 130, from the intermediate storage device 130 to the drying device 140, and from the drying device 140 to the pyrolysis device 150 can be made airtight.

[0122] It should also be noted that potentially environmentally harmful gases formed in the comminution device 120, the intermediate storage device 130, the drying device 140, and the pyrolysis device 150 can be supplied via lines 184, 185, 186, 187 to an exhaust gas treatment device 190 of a known type, in which they are treated in an environmentally friendly manner.

[0123] Examples

[0124] Examples 1 - 5

[0125] Mix the LFP battery waste with a single-component or two-component alkaline earth F scavenger (SCV) system at a stoichiometric ratio of fluoride to alkaline earth metal (F:M) of 1.6:1 - 2.1:1. The compositions of the starting materials used are shown in Tables 1 and 2. EA )

[0126] Table 1

[0127] BM C F Al Cu Fe Li Mg P 1 28.50％ 3.50％ 2.10％ 5.40％ 17.20％ 2.40％ 0.01％ 12.0％ 2 41.40％ 3.60％ 1.90％ 2.40％ 13.70％ 2.20％ 0.03％ 8.30％

[0128] Table 2

[0129]

[0130] * Comparative example

[0131] Place the material in a quartz glass reaction vessel and first heat-treat it under inert conditions at a temperature of 300 °C - 550 °C for 1 - 2 h, and then calcine it under aerobic conditions at 500 °C - 550 °C for 1 - 2 h.

[0132] In Tests I - III, the fluoride is quantitatively retained in the solid (>95%). Keep the conditions of Test IV similar, except that no additional scavenger is added. In Test V, no scavenger is added, and the LFP battery waste material is heat-treated under inert conditions at a temperature of 500 °C for 2 h. All products obtained are red-brown solids.

[0133] Leaching Example A

[0134] Disperse 20 g of Product I in 92.5 g of deionized water and heat it to 100 °C with stirring. Slowly add 7.5 g of 96% sulfuric acid within 15 minutes. After 2 h at 100 °C, allow the mixture to cool to ambient temperature and then filter to remove the solid. After washing with deionized water and drying under reduced pressure, 18.8 g of solid residue and 105.1 g of leaching solution can be obtained.

[0135] Leaching Example B

[0136] Disperse 20 g of Product II in 92.5 g of deionized water and heat it to 100 °C with stirring. Slowly add 7.5 g of 96% sulfuric acid within 15 minutes. After 8 h at 100 °C, allow the mixture to cool to ambient temperature and then filter to remove the solid. After washing with deionized water and drying under reduced pressure, 20 g of solid residue and 103.8 g of leaching solution can be obtained.

[0137] Leaching Example C

[0138] Disperse 20 g of Product III in 110 g of deionized water and heat to 100 °C with stirring. Slowly add 10 g of 96% sulfuric acid within 15 minutes. After 3 h at 100 °C, allow the mixture to cool to ambient temperature and then filter to remove the solid. After washing with deionized water and drying under reduced pressure, 19 g of solid residue and 117.6 g of leaching solution can be obtained.

[0139] Leaching Example D

[0140] Disperse 20 g of Product IV in 110 g of deionized water and heat to 100 °C with stirring. Slowly add 10 g of 96% sulfuric acid within 15 minutes. After 3 h at 100 °C, allow the mixture to cool to ambient temperature and then filter to remove the solid. After washing with deionized water and drying under reduced pressure, 18 g of solid residue and 115.9 g of leaching solution can be obtained.

[0141] The measured leaching efficiency is shown in Table 3, and the composition of the obtained leaching solution is shown in Table 4.

[0142] Table 3

[0143] Test Li - LE Fe - LE P - LE F - LE Mg - LE A 95.6％ 5.7％ 8.1％ / 41.3％ B 91.8％ 14.1％ 5.5％ / / C 96.8％ 4.3％ 6.4％ 47.3％ 25.3％ D 92.3％ 7.5％ 8.2％ 77.9％ /

[0144] Table 4

[0145] Test Li Fe P Cu F Ca Mg A 0.51％ 0.22％ 0.18％ 0.49％ n.d. n.d. 0.20％ B 0.46％ 0.55％ 0.13％ 0.83％ n.d. n.d. n.d. C 0.39％ 0.11％ 0.10％ 0.48％ 0.29％ 0.049％ 0.064％ D 0.41％ 0.21％ 0.14％ 0.53％ 0.47％ n.d. n.d.

[0146] Analysis Method

[0147] Determination of Leaching Efficiency

[0148] The leaching efficiency (LE) is determined using the elemental content measured by ICP-OES. Unless otherwise stated, the leaching efficiency is determined using the elemental content measured in the mother liquor.

[0149] Using the following formula:

[0150]

[0151] Where

[0152] E represents a given element,

[0153] ML represents the mother liquor,

[0154] E ICP-ML is the percentage-based content measured in the mother liquor,

[0155] m(E ML ) is the weight content of the element in the mother liquor,

[0156] m(E Max ) is the maximum yield of the element, which is based on the amount of the element in the solid before leaching, and

[0157] LE E is the leaching efficiency of the corresponding element.

[0158] In Examples 2c, 2d, and 6b, the leaching efficiency was determined from the filter residue.

[0159] All calculations were similar to Equations (1) and (2), except for each instance where FC (filter cake) was used instead of ML. The corresponding LE E is:

[0160]

[0161] Proportion of fluorine volatilized

[0162] All calculations were performed using the element contents determined by ICP - OES. Fluoride volatilization was detected by analyzing the fluorine content of the solid before and after heat treatment, or alternatively by analyzing the fluorine content of the 10% KOH scrubber liquid.

[0163]

[0164] F% is the percentage of fluoride in the solid or scrubber liquid, respectively.

[0165] Elemental analysis

[0166] This section describes the analytical methods for quantitatively determining the composition of the composite materials disclosed herein.

[0167] Fluorine content

[0168] The determination of fluorine uses a combination of combustion and measurement by a fluoride - selective electrode.

[0169] Combustion

[0170] Approximately 1 - 100 mg of the sample was weighed into a combustion boat. Capsules made of gelatin or tin could be used for sample weighing and transfer. Add V 2 O 5To promote combustion. The boat is introduced into a combustion tube heated to approximately 1,000 °C - 1,100 °C via a sample application device. The sample is combusted in an oxygen stream containing water vapor. During combustion, fluorine-containing components form hydrogen fluoride. The combustion gas containing the formed hydrogen fluoride is absorbed in an absorption solution. A total ion strength adjustment buffer (e.g., TISAB IV buffer solution (ASTM D1179)) is used as the absorption solution. The solution is transferred to an ion-sensitive measuring cell and filled to 50 mL with TISAB and ultrapure water (1:1).

[0171] The combustion system used is a Mitsubishi AQF-2100H automatic rapid furnace (a1-envirosciences GmbH, Düsseldorf 40595, Germany).

[0172] · Oven inlet temperature: approximately 1,000 °C

[0173] · Oven outlet temperature: approximately 1,100 °C

[0174] · Combustion gas (oxygen): approximately 200 mL / min

[0175] · Carrier gas (argon): approximately 100 mL / min

[0176] · Water flow rate: 0.2 mL / min

[0177] Detection by fluoride ion selective electrode

[0178] In the absorption solution, fluoride is measured by a fluoride ion-selective electrode (e.g., ISE 6.0502.150, Deutsche Metrohm GmbH & Co. KG, Villingen-Schwenningen 70794, Germany). For quantification, external calibration of the electrode is performed using fluoride standard solutions of different concentrations (e.g., 0.1, 1.0, 10, and 100 mg / L fluoride). The calibration solutions are automatically prepared by diluting a fluoride stock solution with TISAB solution and ultrapure water (1:1).

[0179] Metal content

[0180] Elemental analysis is performed using a combination of acid digestion and alkaline borate fusion digestion and analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) on an inductively coupled plasma optical emission spectrometer (e.g., Agilent 5110 ICP-OES, Agilent Technologies Germany GmbH & Co. KG, Waldbronn 76337, Germany).

[0181] Weigh an aliquot of the sample material (e.g., about 0.2 g) into a volumetric flask and dissolve it in 30 ml of HCl under gentle heating. After cooling, filter out the insoluble residue and incinerate it together with the filter paper in a Pt crucible above an open flame. Subsequently, calcine the residue in a muffle furnace at about 600 °C and then mix it with 1.0 g of K 2 CO 3 -Na 2 CO 3 / Na 2 B 4 O 7 flux mixture (4:1), and melt it above an open flame until a clear melt is obtained. After cooling, dissolve the melt cake in deionized (DI) water under gentle heating and add 12 ml of HCl. Finally, add this solution to the initial filtered solution in the volumetric flask and make up the volume to its final volume with DI water. Each sample is prepared in triplicate. Prepare blank samples in a similar manner.

[0182] The digestion solution is analyzed by inductively coupled plasma - optical emission spectrometry (ICP - OES) using external calibration. For some samples, the digestion solution can be diluted before analysis, for example, diluted to suit the concentration and calibration range of the corresponding analyte.

[0183] Phosphorus content

[0184] The phosphorus content is determined by a combination of acid digestion and alkaline - borate fusion digestion followed by measurement via inductively coupled plasma optical emission spectrometry (ICP - OES).

[0185] Weigh an aliquot of the sample material between 0.13 g and 0.18 g into a volumetric flask and dissolve it in HCl (about 6 mol / l) under gentle heating. After cooling, filter out the insoluble residue and incinerate it together with the filter paper in a Pt crucible above an open flame. Subsequently, calcine the residue in a muffle furnace at about 600 °C and then mix it with 1.0 g of K 2 CO 3 -Na 2 CO 3 / Na 2 B 4 O 7 flux mixture (4:1), and melt it above an open flame until a clear melt is obtained. After cooling, dissolve the melt cake in DI water under gentle heating and add 12 ml of HCl. Finally, add this solution to the initial filtered solution in the volumetric flask and make up the volume to 100 ml with DI water. Each sample is prepared in triplicate. Prepare blank samples in a similar manner.

[0186] The digestion solution was analyzed by inductively coupled plasma - optical emission spectrometry (ICP - OES) using an ICP - OES spectrometer (Agilent 5110 ICP - OES, Agilent Technologies Deutschland GmbH, Waldbronn 76337, Germany) under the following conditions: wavelength: P(R) 178.222 nm, internal standard: Sc(R) 361.383 nm, calibration: external, dilution factor: 1 (direct measurement).

[0187] Carbon content

[0188] The carbon content was determined by elemental analysis in an automatic analyzer (vario EL Cube, Elementar Analysensysteme GmbH, Langenselbold 63505, Germany). The sample (2 - 3 mg) was weighed into a tin capsule. Using copper oxide as a combustion catalyst, the capsule with the sample was burned in a helium / oxygen atmosphere at approximately 1100 °C. After separating the combustion gases by chromatography, the carbon was determined as CO 2 and measured. Detection and quantification were carried out by measuring the thermal conductivity using a TCD.

Claims

1. An apparatus (100) for recycling lithium iron phosphate battery materials, the apparatus comprises: - a comminution device (120) configured to comminute lithium iron phosphate battery materials in a comminution space (120a); - an intermediate storage device (130) arranged downstream of the comminution device (120) and including an intermediate storage space (130a) having a stirring tool (134); - a drying device (140) arranged downstream of the intermediate storage device (130) and including a drying space (140a) having a stirring tool (144); - a pyrolysis device (150) arranged downstream of the drying device (140) and configured to pyrolyze the comminuted and dried lithium iron phosphate battery materials in a pyrolysis space (150a); - an oxidation device (170) arranged downstream of the pyrolysis device (150) and configured to oxidize the pyrolyzed lithium iron phosphate battery materials in an oxidation space (170a); - at least one screening device (160) configured to separate the components of the comminuted lithium iron phosphate battery materials from each other.

2. The apparatus according to claim 1, wherein, the comminution device (120) is equipped with a screening device (122).

3. The apparatus according to claim 1 or 2, wherein, the intermediate storage device (130) is equipped with a cooling device (136).

4. The apparatus according to any one of claims 1 to 3, wherein, the screening device (160) configured to separate the components of the comminuted lithium iron phosphate battery materials from each other is arranged upstream of the pyrolysis device (150).

5. The apparatus according to any one of claims 1 to 4, wherein, the screening device (160) configured to separate the components of the comminuted and pyrolyzed lithium iron phosphate battery materials from each other is arranged downstream of the oxidation device (170).

6. The apparatus according to any one of the preceding claims, further comprising an exhaust gas treatment device (190) which is connected to one or more of the comminution space (120a), the intermediate storage space (130a), the drying space (140a), and the pyrolysis space (150a) via corresponding gas supply pipelines (184, 185, 186, 187) and is configured to treat the gas formed in one or more of the comminution space (120a), the intermediate storage space (130a), the drying space (140a), and the pyrolysis space (150a).

7. The apparatus according to any one of the preceding claims, further comprising a filling device (180) arranged downstream of the oxidation device (170).

8. The apparatus according to any one of the preceding claims, wherein, the pyrolysis device (150) includes a rotary kiln.

9. The apparatus according to any one of the preceding claims, wherein, the oxidation device (170) includes a rotary kiln.

10. A method for recycling lithium iron phosphate battery materials, the method comprising a) providing lithium iron phosphate battery materials to a comminution device, b) Pulverize the lithium iron phosphate battery material in the pulverizing device, c) Transfer the pulverized lithium iron phosphate battery material to a drying device, d) Dry the pulverized lithium iron phosphate battery material, e) Transfer the pulverized and dried lithium iron phosphate battery material to a pyrolysis device, f) While bringing the pulverized and dried lithium iron phosphate battery material into contact with an inert gas and a reducing gas in-situ generated by the thermal decomposition of the pulverized and dried lithium iron phosphate battery material, heat the pulverized and dried lithium iron phosphate battery material to a temperature of 400 °C to 630 °C to obtain a pyrolyzed lithium iron phosphate battery material; g) While bringing the pyrolyzed lithium iron phosphate battery material into contact with an oxygen-containing gas, oxidize the pyrolyzed lithium iron phosphate battery material at a temperature in the range of 500 °C to 700 °C to obtain an oxidized lithium iron phosphate battery material.

11. The method according to claim 10, wherein, Step b) includes the following steps: I. Feed the material into a first pulverizing device and pulverize the material to obtain first particles having a maximum diameter of 50 mm or less; II. Feed the first particles obtained in step I) into a second pulverizing device and pulverize the first particles to obtain second particles having a maximum diameter of 20 mm or less; III. Feed the second particles obtained in step II) into a first separating device to remove a first fine fraction composed of particles having a size of <500 μm from the second particles; IV. Feed the second particles obtained in step III) into a third pulverizing device and pulverize the second particles to generate a second fine fraction composed of particles having a size of <500 μm; V. Combine the first fine fraction and the second fine fraction.

12. The method according to claim 10 or 11, wherein, The lithium iron phosphate battery material includes at least one selected from the following: lithium iron phosphate batteries, lithium iron phosphate battery waste, lithium iron phosphate battery production waste, lithium iron phosphate battery cell production waste, lithium iron phosphate cathode active material, and combinations thereof.

13. The method according to any one of claims 10 to 12, wherein, The lithium iron phosphate battery material contains copper, aluminum, lithium, iron, phosphorus, or combinations thereof.

14. The method according to any one of claims 10 to 13, wherein, The pulverized and dried lithium iron phosphate battery material contains 1 wt.-% to 50 wt.-% of carbon, and / or 0.1 wt.-% to 10 wt.-% of aluminum, and / or 0.5 wt.% to 7 wt.-% of copper, and / or 0 wt.-% to 11 wt.-% of manganese, and / or 1 wt.-% to 7 wt.-% of lithium, and / or 10 wt.-% to 35 wt.-% of iron, and / or 5 wt.-% to 20 wt.-% of phosphorus based on the total weight of the pulverized and dried lithium iron phosphate battery material.

15. Use of the pyrolyzed lithium iron phosphate battery material produced by the method according to any one of claims 10 to 14 in recovering lithium and / or copper from lithium iron phosphate battery materials.

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