Functional substrate manufacturing apparatus

Abstract

The present invention provides methods for manufacturing functional substrates. [Solution] A method for manufacturing a functional substrate includes a reduction step (S21) in which a reducing gas is brought into contact with a substrate mainly composed of a compound containing at least phosphorus and a transition metal, and a carbonization step (S22) in which a carbonization gas is brought into contact with the substrate that has been in contact with the reducing gas.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a functional base material, a functional base material, a secondary battery, a positive electrode material, and a functional base material manufacturing apparatus.

Background Art

[0002] There are reaction apparatuses for manufacturing a desired product by providing a predetermined atmosphere to a granular processed material. For example, generally, a reaction apparatus called a rotary kiln heats a hollow reaction vessel that rotates around a central axis, and manufactures a desired product by passing a material through the reaction vessel while rolling the material. Also, for example, a reaction apparatus called a roller hearth kiln manufactures a desired product by passing a processed material or a workpiece through a tunnel-shaped reaction vessel. In addition, various other reaction apparatuses have been developed.

[0003] For example, Patent Document 1 discloses the following reaction apparatus. The reaction apparatus includes a screw feeder main body that serves as a pressure reaction vessel, a catalyst supply unit that introduces a catalyst into the screw feeder main body, and a lower hydrocarbon supply unit that introduces a lower hydrocarbon into the screw feeder main body. Further, this reaction apparatus includes a screw that conveys the generated nano-carbon, a solid delivery unit that delivers the catalyst and nano-carbon conveyed by the screw, and a gas delivery unit that delivers the generated hydrogen outside the feeder main body.

[0004] On the other hand, the present inventors have studied a method for manufacturing a functional base material. The functional base material is a base material mainly composed of a compound containing at least phosphorus and a transition metal (for example, lithium iron phosphate), and refers to a functional base material containing nano-carbon (for example, one or more carbon nanotubes) grown starting from the surface of the base material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, the reaction apparatus described in Patent Document 1 does not mention anything about the method for producing the functional substrate.

[0007] Other challenges and novel features will become apparent from the description and accompanying drawings in this specification. [Means for solving the problem]

[0008] A method for producing a functional substrate according to one embodiment includes a reduction step of contacting a substrate mainly composed of a compound containing at least phosphorus and a transition metal with a reducing gas, and a carbonization step of contacting the substrate that has been in contact with the reducing gas with a carbonizing gas. [Effects of the Invention]

[0009] According to this disclosure, a method for manufacturing a functional substrate, a functional substrate, a secondary battery, a cathode material, and an apparatus for manufacturing a functional substrate can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of the reaction apparatus according to Embodiment 1. [Figure 2] This is a block diagram of the reaction apparatus according to Embodiment 1. [Figure 3] This is a flowchart of the processes performed by the reactor. [Figure 4] This is a side view of the reaction apparatus according to Embodiment 2. [Figure 5] This is a side view of the reaction apparatus according to Embodiment 3. [Figure 6] This is a diagram illustrating the manufacturing process of a lithium-ion battery (an example of a secondary battery as described herein). [Modes for carrying out the invention]

[0011] The present invention will be described below through embodiments of the invention, but the invention claimed is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means of solving the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary.

[0012] <Embodiment 1 (Reference Example)> Referring to Figure 1, the main configuration of the reaction apparatus according to Embodiment 1 (reference example) will be described. Figure 1 is a side view of the reaction apparatus 10 according to Embodiment 1. For ease of understanding, the reaction apparatus 10 shown in the figure is shown in a partially cropped state.

[0013] The reaction apparatus 10 is a device for producing a product by applying predetermined physical stimuli or other conditions to a granular material, for example. The reaction apparatus 10 comprises a cylindrical reaction vessel 100, a material supply unit (supply port 101) for supplying the material R10 to the reaction vessel 100, a conveying device (screw 120) for transporting the material R10 supplied to the reaction vessel 100 from the supply side to the discharge side, a fluid supply unit (first fluid inlet 131, first fluid outlet 132, first valve 134, etc.) for supplying fluid in contact with the transported material into the reaction vessel 100, and a temperature control unit (temperature control region 110, etc.) for controlling the temperature of the reaction vessel 100 in each of the different regions along the axis AX100 of the reaction vessel 100. Furthermore, physical stimuli are not particularly limited to any means used in the process of transforming a material into a product, but include, for example, temperature changes such as heating and cooling. Physical stimuli include, for example, stress transfer such as stirring, mixing, kneading, and grinding. Physical stimuli include, for example, reactions involving the transfer of electrons or radicals. Physical stimuli include, for example, contact with a catalyst.

[0014] Within the reaction vessel 100, the material R10 supplied to the supply port 101 side of the reaction vessel 100 is heated while being transported to the outlet port 102 side of the reaction vessel 100, and a predetermined fluid that comes into contact with the transported material R10 is supplied into the reaction vessel 100, thereby continuously processing the material R10 (processing material) at a predetermined temperature. The processing material may be a solid, a fluid, or a mixture of both. In order to stir the processing material while transporting it, the reaction vessel 100 itself may be rotatable, or a rotatable screw 120 may be provided inside the reaction vessel 100.

[0015] Furthermore, the number and configuration of reaction vessels 100 in the reaction apparatus 10 are not limited. For example, two or more reaction vessels may be configured in series or in parallel. In this case, each reaction vessel may be equipped with a material supply unit, a product delivery unit, a drive unit, a conveying unit, a temperature control unit, a fluid supply unit, etc.

[0016] The type and state of the processed material are not particularly limited, but they may be inorganic substances such as metal oxides or metal sulfides containing lithium as one of their components, or organic substances such as hydrocarbons. The processed material may be a solid such as a powder or granules, or a fluid such as a liquid or gas. Furthermore, the processed material may pass through intermediates in the process of transformation to the product. The form and state of the intermediate are not particularly limited. An intermediate may be, for example, the product of each reaction when two or more reactions are carried out stepwise. In that case, the intermediate may be, for example, an anhydrous compound produced by heating a hydrated compound. Alternatively, an intermediate may be a calcined body in which at least a part of the processed material has undergone grain growth or sintering. An intermediate may be in a state in which at least a part of the processed material has been liquefied or vaporized. An intermediate may be in any form or state other than those described above.

[0017] In addition, the type and state of the product are not particularly limited. The product may be a solid such as a powder or granule, or a fluid such as a liquid or gas. The product may be a mixture containing members other than the processed material such as a catalyst or a transport auxiliary member. The product may be a mixture containing two or more compounds, such as a main product and a by-product.

[0018] In addition, the shape and size of the processed material and the product are not particularly limited. However, when the shape is a lump, the diagonal length is preferably 0.01 mm to 50 mm, more preferably 0.5 to 20 mm. Further, when the shape of the processed material and the product is a lump, the ratio (aspect ratio) of the diagonal length is preferably 1 to 10, more preferably 1.3 to 1.8.

[0019] The reaction apparatus 10 mainly includes a reaction vessel 100, a temperature control region 110, a screw 120, a first fluid control region 130, and a second fluid control region 140.

[0020] The reaction vessel 100 is, for example, a cylindrical cylinder and has a supply port 101 for receiving the supplied processed material and a product outlet 102. The supply port 101 is an example of the processed material supply section of the present disclosure. The reaction vessel 100 also has an intermediate section between the supply port side (supply port 101) and the outlet side (outlet 102). Note that the shape and configuration of the reaction vessel 100 are not particularly limited. For example, the cross-sectional shape of the reaction vessel 100 may be circular, elliptical, polygonal such as quadrilateral, or other shapes. For example, the reaction vessel 100 may be composed of one member, or two or more members may be connected. When two or more members are connected, for example, fastening means such as bolts may be used at the location where the members are connected. The reaction vessel 100 is made of a material that can withstand temperature changes that occur when producing products in the furnace, and can withstand contact with substances supplied to the furnace (such as materials to be processed) and substances being produced (such as products). The reaction vessel 100 and the screw 120 can be made of, for example, alloys, ceramics, carbon, and composite materials containing two or more of them. Alloys are metallic components that contain at least one alloying element such as nickel, cobalt, chromium, molybdenum, tungsten, tantalum, titanium, iron, copper, aluminum, silicon, boron, and carbon. Ceramics are ceramic components such as oxides such as alumina and zirconia, carbides such as silicon carbide and titanium carbide, nitrides such as silicon nitride and titanium nitride, and borides such as chromium boride. Carbon is carbon components such as crystalline graphite and fiber-reinforced graphite.

[0021] The reaction apparatus 10 shown in Figure 1 lies horizontally and has a supply port 101 at its upper left end and a discharge port 102 at its lower right end. The reaction vessel 100 shown in Figure 1 receives the material R10 from the supply port 101. The reaction apparatus 10 rotates a screw 120 located inside the reaction vessel 100 to transport the material R10 received by the reaction vessel 100 from the supply port 101 side through the intermediate section A3 to the discharge port 102 side of the reaction vessel 100. The reaction apparatus 10 produces product R11 from the material R10 by passing the material R10 through the intermediate section A3 of the reaction vessel 100. The reaction vessel 100 then discharges the produced product R11 from the discharge port 102.

[0022] The temperature control region 110 includes a temperature control device, i.e., a heating device or a cooling device, and controls the temperature of the reaction vessel at a predetermined position in the intermediate section A3 between the supply port 101 and the outlet port 102. The temperature control region 110 is an example of a temperature control unit in this disclosure. The temperature control region 110 shown in Figure 1 has a heating device that surrounds the cylindrical reaction vessel 100 in the intermediate section A3 of the reaction vessel 100. The heating device includes any temperature-controllable heater, such as a sheath heater, coil heater, or ceramic heater. The heating device heats in a range from room temperature to about 900 degrees Celsius. Furthermore, the temperature control region 110 can set different temperatures for each region of the intermediate section A3 of the reaction vessel 100 along the axis AX120 of the screw 120, which will be described later. For example, the temperature control region 110 can control the temperature applied to the processed material R10 in the first fluid control region 130 and the second fluid control region 140, which will be described later.

[0023] The temperature control region 110 may also include a control device for controlling a heating or cooling device. For example, the temperature control region 110 may have a thermometer at a predetermined location in the reaction vessel 100 for monitoring the temperature. Alternatively, if the heating device in the reaction vessel 100 operates on the principle of heating by passing an electric current, the temperature may be controlled by monitoring the current value.

[0024] The temperature control region 110 may have a configuration that performs heating or cooling by circulating, for example, water or oil. Alternatively, the temperature control region 110 may have a configuration that performs cooling using, for example, a Peltier element. With the above configuration, the temperature control region 110 can set various temperature distributions along the axis AX120 of the screw 120 in the reaction vessel 100.

[0025] As described above, the temperature control region 110 can control the temperature of the reaction vessel 100 (intermediate section A3) for each of the different regions along the axis AX100 of the reaction vessel 100.

[0026] The screw 120 extends from the supply port 101 side to the outlet port 102 side of the reaction vessel 100, thereby rotating to transport the processed material R10 supplied from the supply port 101 toward the outlet port 102. The screw 120 shown in Figure 1 has a spiral projection 121 formed around an axis that extends in the left-right direction. As this projection 121 rotates while in contact with the processed material R10, the screw 120 transports the processed material R10 from left to right in Figure 1. The transport device of this disclosure is not limited in shape or transport method, as long as it is capable of transporting processed material or products. The transport device may be a screw provided inside the reaction vessel 100 so as to extend from the supply port 101 side to the outlet port 102 side of the reaction vessel 100, or the transport device may be a drum provided inside the reaction vessel 100 so as to extend from the supply port 101 side to the outlet port 102 side of the reaction vessel 100. The conveying device may be a belt conveyor installed inside the reaction vessel 100 so as to extend from the supply port 101 side to the discharge port 102 side of the reaction vessel 100. The conveying device may be a blower installed inside the reaction vessel 100. The conveying device may be a vibration generator installed inside the reaction vessel 100. The conveying device may be anything other than those described above.

[0027] The size of the conveying device is not particularly limited and may, for example, be shorter than the total length of the reaction vessel 100. The material used to form the conveying device is not particularly limited, but it is desirable that the conveying device be made of a material that can tolerate temperature changes that occur during product production and contact with the substance supplied into the vessel, similar to the reaction vessel 100. The conveying device may be made of, for example, alloys, ceramics, carbon, and composite materials containing two or more of these.

[0028] Note that the shape of the protrusion 121 shown in Figure 1 is just one example, and the shape of the protrusion 121 is not limited to this. The protrusion 121 may have different shapes in each region of the reaction vessel 100. More specifically, for example, the pitch of the spiral of the protrusion 121 may vary. Also, the spiral shape of the protrusion 121 may have two spirals instead of one. Furthermore, the protrusion 121 may have parts that are not spiral-shaped. This allows the reaction apparatus 10 to set the speed at which objects move and their behavior when moving in each region of the reaction vessel 100. More specifically, for example, the reaction apparatus 10 transports, stirs, mixes, kneads, or grinds objects in the reaction vessel 100.

[0029] The screw 120 is pivotally supported at both ends A1 and A2 of the reaction vessel 100. The screw 120 shown in Figure 1 is connected to a drive unit 150 at one end B1. The drive unit 150 is an example of the drive unit of this disclosure. The drive unit 150 includes a motor 151 provided at one end A1 of the reaction vessel 100, and a reduction gear 152 provided between the motor 151 and one end A1 of the reaction vessel 100. The reduction gear 152 includes an input shaft connected to the rotating shaft of the motor 151 and an output shaft connected to one end B1 of the screw 120, and rotates the screw 120 by reducing the rotation of the rotating shaft of the motor 151 and transmitting it to the screw 120. The drive unit 150 may be set to allow for variable speed control of the rotational speed of the screw 120. In this case, the drive unit 150 may be a motor with a variable rotational speed, or it may be a combination of a motor with a constant rotational speed and a reduction gear with a changeable reduction ratio.

[0030] The first fluid control region 130 includes a first fluid inlet 131 and a first fluid outlet 132 for passing the first fluid into the reaction vessel 100 in a predetermined region in the intermediate section A3. The first fluid control region 130 is located in the reaction vessel 100 between the supply port 101 and the second fluid control region 140. The first fluid inlet 131 is connected to the first fluid supply pipe 133 and supplies the first fluid supplied from the first fluid supply pipe 133 to the reaction vessel 100. The first fluid supply pipe 133 includes a first valve 134 for adjusting the flow rate of the first fluid. The first fluid outlet 132 is a hole for discharging the fluid from the first fluid control region 130 to the outside of the reaction vessel 100.

[0031] With the above configuration, the reaction apparatus 10 reacts the material R10 with the first fluid in the first fluid control region 130 to produce an intermediate product. The reaction apparatus 10 also discharges the fluid after the reaction to the outside of the first fluid control region 130. The reaction apparatus 10 can also promote the reaction with the first fluid by transporting the material R10 or the product with the rotating screw 120 and bringing it into contact with the first fluid. The state and form of the first fluid are not limited as long as it is fluid. That is, the first fluid may be a gas, a liquid, or a slurry in which powders or granules are dispersed in a liquid. The components constituting the first fluid may be one type or two or more types.

[0032] The second fluid control region 140 includes a second fluid inlet 141 and a second fluid outlet 142 for allowing the second fluid to pass through a region different from the first fluid control region 130 in the intermediate section A3. In other words, the second fluid control region 140 may have the same configuration as the first fluid control region 130 in a region different from the first fluid control region 130.

[0033] The second fluid control region 140 is located in the reaction vessel 100 between the first fluid control region 130 and the outlet 102. The second fluid inlet 141 is connected to the second fluid supply pipe 143, supplying the second fluid from the second fluid supply pipe 143 to the reaction vessel 100. The second fluid supply pipe 143 includes a second valve 144 for adjusting the flow rate of the second fluid. The second fluid outlet 142 is a hole for discharging the fluid from the second fluid control region 140 to the outside of the reaction vessel 100.

[0034] With the above configuration, the reactor 10 reacts the intermediate material that has passed through the first fluid control region 130 with the second fluid in the second fluid control region 140 to produce product R11. The reactor 10 also discharges the fluid after the reaction outside the second fluid control region 140. The state and form of the second fluid are not limited as long as it is fluid. That is, the first fluid may be a gas, a liquid, or a slurry in which powders or granules are dispersed in a liquid. The components constituting the first fluid may be one type or two or more types.

[0035] The configuration of the reaction apparatus 10 has been described above, but the reaction apparatus 10 according to Embodiment 1 is not limited to the above configuration. For example, there may be two or more screws 120, as long as there is one or more. That is, the reaction apparatus 10 may have a plurality of screws 120 arranged in parallel.

[0036] The cross-sectional shape of the reaction vessel 100 in a plane perpendicular to the axis of the screw 120 may be a combination defined by a Reuleaux constant width figure. In this case, the cross-sectional shape of the convex portion 121 of the screw 120 has a shape that is a combination of multiple arcs corresponding to a Reuleaux constant width figure. For example, if the cross-sectional shape inside the reaction vessel 100 is circular, the cross-sectional shape of the screw 120 has a Reuleaux constant width figure composed of three arcs.

[0037] The reaction vessel 100 is not limited to being laid horizontally parallel to the horizontal direction; it may also have a predetermined angle with respect to the horizontal plane, and the reaction vessel 100 may have an inclined surface. The reaction apparatus 10 has a first fluid control region 130 and a second fluid control region 140 in the intermediate section A3, but it may also have a configuration for passing another fluid through. That is, the reaction apparatus 10 may have three or more fluid control regions. The above-described reaction apparatus 10 is controlled by a control device described later.

[0038] Next, the functions of the reactor 10 will be described with reference to Figure 2. Figure 2 is a block diagram of the reactor 10 according to Embodiment 1. In addition to the configuration shown in Figure 1, the reactor 10 includes a control device 200, a temperature control device 210, a first fluid control device 230, a second fluid control device 240, and an information input / output unit 250.

[0039] The control device 200 is a circuit board that includes computing devices such as a CPU (Central Processing Unit) and an MCU (Micro Controller Unit). The control device 200 is communicatively connected to the temperature control device 210, the first fluid control device 230, the second fluid control device 240, and the information input / output unit 250, and controls the configuration of each of them. The control device 200 realizes its functions through hardware and software mounted on the circuit board.

[0040] The control device 200 has the following main functional components: an overall control unit 201, a temperature control unit 202, a screw rotation control unit 203, a first fluid control unit 204, a second fluid control unit 205, an IF control unit 206, and a memory unit 207. These functional components of the control device 200 may be integrated or discrete. Furthermore, these functional components of the control device 200 may be realized by the coordinated operation of multiple separate devices.

[0041] The overall control unit 201 connects to each functional configuration of the control device 200 and controls the overall operation of these functions. For example, the overall control unit 201 may issue operation instructions to the screw rotation control unit 203 according to the temperature state supplied by the temperature control unit 202.

[0042] The temperature control unit 202 is connected to the temperature control device 210 and controls the temperature of the reaction vessel 100 in the temperature control region 110. The temperature control unit 202 has at least one of a heating device and a cooling device. The temperature control unit 202 may also have one or more thermometers for controlling the temperature.

[0043] The screw rotation control unit 203 is connected to the drive unit 150 and controls the operation of the drive unit 150. The screw rotation control unit 203 may have, for example, a motor drive circuit for driving the motor (motor 151) of the drive unit 150. The screw rotation control unit 203 may also have a rotation sensor for monitoring the rotation speed of the motor (motor 151).

[0044] The first fluid control unit 204 controls the flow of the first fluid in the first fluid control region 130. More specifically, the first fluid control unit 204 is connected to the first fluid control device 230 and controls the operation of the first fluid control device 230. The first fluid control device 230 includes a first valve 134 for pumping the first fluid. The second fluid control unit 205 controls the flow of the second fluid in the second fluid control region 140. More specifically, the second fluid control unit 205 is connected to the second fluid control device 240 and controls the operation of the second fluid control device 240. The second fluid control device 240 includes a second valve 144 for pumping the second fluid.

[0045] The IF control unit 206 (IF = Interface) is connected to the information input / output unit 250 and serves as an interface for exchanging information with the user via the information input / output unit 250. In other words, the IF control unit 206 receives operations from the user via the information input / output unit 250 and appropriately supplies information related to the received operations to each component of the control device 200. The IF control unit 206 also controls the state of the display unit of the information input / output unit 250.

[0046] The storage unit 207 is a storage device that includes non-volatile memory such as flash memory or an SSD (Solid State Drive). The storage unit 207 stores a program for the reaction device 10 to realize the functions described in this disclosure. The storage unit 207 also includes volatile memory and temporarily stores predetermined information when the control device 200 is operating. The information input / output unit 250 has, for example, buttons, switches, or a touch panel for receiving operations from the user. The information input / output unit 250 also includes a display device for presenting information to the user.

[0047] The functional blocks of the reaction apparatus 10 have been described above. With the above configuration, the reaction apparatus 10 transports the received material R10 by screw 120, controls the temperature of the reaction vessel 100, and controls the atmosphere in the first fluid control region 130 and the second fluid control region 140.

[0048] Next, with reference to Figure 3, the method for producing the product (product production method) performed by the reactor 10 will be described. Figure 3 is a flowchart of the process performed by the reactor 10. The flowchart shown in Figure 3 starts, for example, by starting the supply of the material R10 to the reactor 10.

[0049] First, the reaction apparatus 10 receives a predetermined material R10 from the supply port 101 (step S11).

[0050] Next, the control device 200 of the reaction apparatus 10 controls the temperature by driving a heating or cooling device in the temperature control region 110 of the reaction vessel 100 via the temperature control unit 202 (step S12).

[0051] Next, the control device 200 of the reaction apparatus 10 drives the drive device 150 via the screw rotation control unit 203. This causes the drive device 150 to rotate the screw 120. The screw 120 then transports the received material R10 toward the discharge port 102 (step S13).

[0052] Next, the control device 200 of the reaction apparatus 10 controls the flow of the first fluid that flows through the first fluid control region 130 via the first fluid control unit 204 (step S14).

[0053] Next, the control device 200 of the reaction apparatus 10 controls the flow of the second fluid that flows through the second fluid control region 140 via the second fluid control unit 205 (step S15).

[0054] Next, the reactor 10 discharges the product R11 that has passed through the second fluid control region 140 from the outlet 102 (step S16).

[0055] The reaction method performed by the reactor 10 has been described above. The method described above follows the flow from when the reactor 10 produces product R11 from the material R10 to when it discharges the produced product R11. However, the reactor 10 may perform temperature control in step S12, for example, before step S11. Also, the reactor 10 may start steps S14 and S15 simultaneously.

[0056] The first embodiment (reference example) has been described above. In the reaction apparatus 10 described above, the reaction apparatus 10 has two fluid control regions (first fluid control region 130 and second fluid control region 140), but the number of fluid control regions in the reaction apparatus 10 may be one or three or more. The reaction apparatus 10 may also have multiple temperature control regions 110 along the axis AX120 direction of the screw 120. In the reaction apparatus 10 described above, multiple fluids are brought into contact separately with the material R10 received from the supply port 101 in the intermediate section A3. The reaction apparatus 10 also controls the temperature of the reaction vessel 100 along the axis AX120 direction of the screw 120 in the intermediate section A3. Furthermore, the reaction apparatus 10 can apply predetermined physical stimulation to the material supplied to the reaction vessel 10 while transporting it. In addition, the reaction apparatus 10 may be configured to connect multiple reaction apparatuses 10 in series or in parallel in order to apply predetermined physical stimulation to the material. The reaction apparatus 10 can perform the aforementioned atmosphere control, temperature control, and physical control simultaneously and with high precision. Therefore, according to Embodiment 1, it is possible to provide a reaction apparatus that can efficiently manufacture a desired product.

[0057] <Embodiment 2> Next, as Embodiment 2, a reaction apparatus 10A used for the manufacture of a functional substrate (functional active material) will be described with reference to Figure 4. Figure 4 is a side view of the reaction apparatus according to Embodiment 2. Hereinafter, the reaction apparatus 10A will be described focusing on the differences from the reaction apparatus 10 of Embodiment 1 (reference example). Note that components identical to those in the reaction apparatus 10 of Embodiment 1 (reference example) will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0058] As shown in Figure 4, the first fluid control region 130A is provided in the upstream region of the intermediate section A3, and includes a reducing gas inlet 131A and a reducing gas outlet 132A for passing reducing gas into the reaction vessel 100 within this upstream region (first fluid control region 130A). In this disclosure, upstream and downstream are defined as follows: At point A, which is any position in the path from the supply port 101 to the outlet port 102, the position closer to the supply port 101 as seen from point A is defined as the upstream position, and the position closer to the outlet port 102 as seen from point A is defined as the downstream position. Furthermore, the upstream side refers to the direction upstream as seen from point A, and the downstream side refers to the direction downstream as seen from point A. The first fluid control region 130A is provided in the reaction vessel 100 between the supply port 101 and the second fluid control region 140A. The reducing gas inlet 131A is connected to the reducing gas supply pipe 133A, to which the reducing gas supply source is connected, and the reducing gas supplied from the reducing gas supply pipe 133A is supplied to the reaction vessel 100. The reducing gas supply pipe 133A includes a first valve (not shown) for adjusting the flow rate of the reducing gas. The reducing gas outlet 132A is a hole for discharging the reducing gas from the first fluid control region 130A to the outside of the reaction vessel 100, and is connected to the reducing gas suction pipe 134A.

[0059] The second fluid control region 140A is provided in a manner corresponding to the downstream region of the intermediate section A3, and includes a carbonization gas inlet 141A and a carbonization gas outlet 142A for passing the carbonization gas to the reaction vessel 100 within this downstream region (second fluid control region 140A). In other words, the second fluid control region 140A may have a configuration equivalent to that of the first fluid control region 130A, but in a different region from that of the first fluid control region 130A.

[0060] The second fluid control region 140A is located in the reaction vessel 100 between the first fluid control region 130A and the outlet 102. The carbonization gas inlet 141A is connected to the carbonization gas supply pipe 143A, and the carbonization gas supplied from the carbonization gas supply pipe 143A is supplied to the reaction vessel 100. The carbonization gas supply pipe 143A includes a second valve (not shown) for adjusting the flow rate of the carbonization gas. The carbonization gas outlet 142A is a hole for discharging the carbonization gas from the second fluid control region 140A to the outside of the reaction vessel 100, and is connected to the carbonization gas suction pipe 144A.

[0061] Furthermore, a reduction gas outlet 160 is provided between the first fluid control region 130A and the second fluid control region 140A. The reduction gas outlet 160 is a hole for discharging the reduction gas from the first fluid control region 130A and the reduction gas from the second fluid control region 140A to the outside of the reaction vessel 100, and is connected to a reduction gas suction pipe 161.

[0062] The reduction gas inlet 131A is an example of the reduction gas supply unit of this disclosure. Similarly, the carbonization gas inlet 141A is an example of the carbonization gas supply unit of this disclosure.

[0063] Next, we will explain the pathway for the reducing gas.

[0064] In the reaction apparatus 10A with the above configuration, a portion of the reducing gas supplied from the reducing gas inlet 131A is drawn to the reducing gas outlet 132A, to which the reducing gas suction pipe 134A is connected, and is forcibly discharged outside the reaction vessel 100 via the reducing gas outlet 132A and the reducing gas suction pipe 134A connected thereto. As a result, a reducing gas flow (see arrow AR1 in Figure 4) is generated in the first fluid control region 130A, flowing from the reducing gas inlet 131A to the reducing gas outlet 132A.

[0065] Furthermore, a portion of the reducing gas supplied from the reducing gas inlet 131A is drawn towards the reducing gas outlet 160, to which the reducing gas suction pipe 161 is connected, and is forcibly discharged outside the reaction vessel 100 via the reducing gas outlet 160 and the reducing gas suction pipe 161 connected thereto. As a result, a reducing gas flow (see arrow AR2 in Figure 4) is generated in the first fluid control region 130A from the reducing gas inlet 131A towards the reducing gas outlet 160.

[0066] The reduction gas flow described above (see arrows AR1 and AR2 in Figure 4) is controlled to a predetermined temperature by the temperature control region 110 heating the reaction vessel 100. This reduction gas flow, controlled to the predetermined temperature, then comes into contact with the material being processed (for example, LiFePO4) passing through the first fluid control region 130A, as described later.

[0067] Next, we will explain the pathway for the carbonization gas.

[0068] In the reaction apparatus 10A with the above configuration, a portion of the carbonization gas supplied from the carbonization gas inlet 141A is drawn to the carbonization gas outlet 142A, to which the carbonization gas suction pipe 144A is connected, and is forcibly discharged outside the reaction vessel 100 via the carbonization gas outlet 142A and the carbonization gas suction pipe 144A connected thereto. As a result, a carbonization gas flow (see arrow AR3 in Figure 4) is generated in the second fluid control region 140A, flowing from the carbonization gas inlet 141A to the carbonization gas outlet 142A.

[0069] Furthermore, a portion of the carbonization gas supplied from the carbonization gas inlet 141A is drawn towards the reduction gas outlet 160, to which the reduction gas suction pipe 161 is connected, and is forcibly discharged outside the reaction vessel 100 via the reduction gas outlet 160 and the reduction gas suction pipe 161 connected thereto. As a result, a carbonization gas flow (see arrow AR4 in Figure 4) is generated in the second fluid control region 140A, flowing from the carbonization gas inlet 141A towards the reduction gas outlet 160.

[0070] The carbonization gas flow described above (see arrows AR3 and AR4 in Figure 4) is controlled to a predetermined temperature by the temperature control region 110 heating the reaction vessel 100. This carbonization gas flow, controlled to the predetermined temperature, then comes into contact with the material being processed (for example, LiFePO4 after the reduction process described later) as it passes through the second fluid control region 140A.

[0071] Furthermore, as described later, the reducing gas (hydrogen) generated in the carbonization process in the second fluid control region 140A is drawn to the reducing gas outlet 160, to which the reducing gas suction pipe 161 is connected, and is forcibly discharged outside the reaction vessel 100 via the reducing gas outlet 160 and the reducing gas suction pipe 161 connected thereto. As a result, a reducing gas flow (see arrow AR4 in Figure 4) is generated in the second fluid control region 140A from the carbonization gas inlet 141A toward the reducing gas outlet 160. The reducing gas discharged from this reducing gas outlet 160 may be reused by supplying it back into the reaction vessel 100 from the reducing gas inlet 131A.

[0072] <Method for manufacturing functional materials> Next, a method for producing a functional substrate using the reaction apparatus 10A described above will be explained with reference to Figure 4. A functional substrate is a substrate mainly composed of a compound containing at least phosphorus and a transition metal (for example, lithium iron phosphate), and contains nanocarbon (for example, one or more carbon nanotubes) grown starting from at least a part of the surface of the substrate. In this disclosure, the transition metal is not particularly limited to any element belonging to the transition metals in the periodic table, that is, an element belonging to groups 3 to 11 of the periodic table. The transition metal may be, for example, iron, cobalt, or nickel. The compound may contain one or more types of transition metals. That is, the compound may contain, for example, iron and nickel in a predetermined ratio.

[0073] Furthermore, in this disclosure, "nanocarbon" refers to a material whose main component is carbon, and whose diameter or short side is 1000 nanometers or less. Nanocarbon may be, for example, carbon nanotubes, carbon fibers, graphene, carbon black, fullerene, etc.

[0074] The following describes a method for producing a functional substrate (C~LiFePO4) that is primarily composed of lithium iron phosphate and contains carbon nanotubes grown starting from its surface.

[0075] In C~LiFePO4, "C~" represents one or more carbon nanotubes that grew starting from the surface of LiFePO4 (mainly the surface activated through the reduction process described later) (mainly grown through the carbonization process described later) (see "Products" in the lower right of Figure 4). In other words, the notation C~LiFePO4 is used for convenience in explaining this disclosure to represent the state in which carbon nanotubes have grown on the surface of a substrate mainly composed of lithium iron phosphate. The substrate is not particularly limited in shape, form, chemical composition, and crystal structure, as long as nanocarbon can be generated on its surface. The shape of the substrate may be spherical, a lump, or a plate. The form of the substrate may be granular, for example. The substrate may be in the form of multiple materials joined together. Furthermore, the substrate may have the same chemical composition and chemical composition as a compound containing at least phosphorus and a transition metal. In other words, the substrate may be a compound containing at least phosphorus and a transition metal. The substrate may be LiFePO4, for example.

[0076] First, we will explain the prerequisites for carrying out the manufacturing method of the functional substrate (C~LiFePO4).

[0077] In the following, a substrate mainly composed of lithium iron phosphate (e.g., lithium iron phosphate with an olivine-type crystal structure) is used as the processing material. Hereinafter, this will be referred to as LiFePO4 or LFP. The shape of the substrate is not particularly limited, but it is preferably in powder or granular form. When the substrate is in powder or granular form, the average particle size is preferably 500 μm or less, more preferably 1 to 200 μm, and even more preferably 10 to 50 μm. By having the average particle size of the substrate within the above range, the carbonization reaction can proceed efficiently. The average particle size may be the value measured by, for example, a laser diffraction / scattering particle size distribution analyzer (e.g., Partica LA-960V2 manufactured by Horiba, Ltd.).

[0078] Furthermore, it is preferable to use hydrogen as the reducing gas. Hereafter, hydrogen will be referred to as H2. Note that the reducing gas is not limited to hydrogen as long as it has reducing properties. For example, carbon monoxide may also be used as the reducing gas.

[0079] Furthermore, it is preferable to use methane, a lower hydrocarbon, as the carbonization gas. Hereinafter, it will be referred to as CH4. Note that the carbonization gas is not limited to methane as long as it has carbonizing properties. For example, propane may also be used as the carbonization gas.

[0080] The H2 supply flow rate (space velocity: SV value) from the reducing gas inlet 131A to the reaction vessel 100 (first fluid control region 130A) should preferably be 80,000 NL / kg / h or less, and more preferably 40,000 to 80,000 NL / kg / h. Hereinafter, NL represents the volume of hydrogen supplied (normal cubic meter), / kg represents the unit weight (per kilogram) of the base material mainly composed of lithium iron phosphate, and / h represents the unit time (per hour) of hydrogen supply.

[0081] The preferred heating temperature for the upstream region (first fluid control region 130A) of the intermediate section A3 is 300 to 1000°C. To facilitate the reaction in the upstream region (first fluid control region 130A), a more preferred heating temperature for the upstream region (first fluid control region 130A) of the intermediate section A3 is 500 to 700°C, and even more preferably 650°C. In this disclosure, heating temperature refers to the temperature of the heating device in the temperature control region, and the temperature of the heating device refers to the temperature measured by a temperature measuring means such as a thermocouple attached to the heating device.

[0082] On the other hand, the supply flow rate (space velocity: SV value (Space Velocity)) of lower hydrocarbons (here, CH4) from the carbonization gas inlet 141A to the reaction vessel 100 (second fluid control region 140A) should preferably be 80,000 NL / kg / h or less in methane equivalent, and more preferably 40,000 to 80,000 NL / kg / h. Here, NL represents the volume of methane supplied (normal cubic meter), / kg represents the unit weight of lithium iron phosphate (per kilogram), and / h represents the unit time (per hour) that methane is supplied. If the SV value is less than 40,000 NL / kg / h, the carbonization reaction will not be sufficiently achieved. Also, if the SV value exceeds 80,000 NL / kg / h, the conversion rate will decrease and the reaction efficiency will worsen.

[0083] The preferred heating temperature for the downstream region (second fluid control region 140A) of the intermediate section A3 is 300 to 1000°C. To facilitate the reaction in the downstream region (second fluid control region 140A), a more preferred heating temperature for the downstream region (second fluid control region 140A) of the intermediate section A3 is 600 to 800°C, and even more preferably 750°C.

[0084] The manufacturing method for C~LiFePO4 is carried out based on the above premise.

[0085] First, a substrate (in this case, LiFePO4 in powder form) mainly composed of a compound containing at least phosphorus and a transition metal is prepared as the material to be processed, and it is supplied from the supply port 101 to the supply port 101 side of the reaction vessel 100 (step S20). The LiFePO4 supplied to the supply port 101 side of the reaction vessel 100 is transported by a rotating screw 120 from the supply port 101 side of the reaction vessel 100 through the intermediate section A3 to the outlet port 102 side of the reaction vessel 100. From the viewpoint of carrying out the reaction sufficiently, it is desirable to set the transport speed to a slow speed that does not impair productivity. For example, the transport speed is preferably 10 meters per hour or less, more preferably 5 meters per hour or less, and even more preferably 1 meter per hour or less. Furthermore, LiFePO4 may be subjected to a predetermined pretreatment. Pretreatment may include, for example, mechanical milling. Pretreatment may include, for example, jet milling. Pretreatment may include, for example, electroless plating. Pretreatment may include a process that amorphousizes at least a portion of the LiFePO4, other than the above. Pretreatment may include a process that deposits a transition metal onto at least a portion of the LiFePO4, other than the above. For example, mechanical milling may be performed using a planetary ball mill apparatus, where LiFePO4 and 5 mm diameter chrome steel balls are placed in a chrome steel container, argon gas is filled as an inert gas, and then the planetary rotation is performed at a rotation speed of 500 rpm for 24 hours. For example, jet milling may be performed using a wet jet mill apparatus, where a slurry in which LiFePO4 and a small amount of iron powder are dispersed in isopropyl alcohol is circulated 10 times in the jet mill flow path. By performing the predetermined pretreatment on LiFePO4 in this way, a substrate mainly composed of LiFePO4 may be produced.

[0086] Next, a reduction process is performed in the upstream region (first fluid control region 130A) of the intermediate section A3 (step S21). In this reduction process, H2 (see arrows AR1 and AR2 in Figure 4) supplied from the reducing gas inlet 131A to the first fluid control region 130A comes into direct contact with the substrate (here, a substrate mainly composed of LiFePO4) passing through the first fluid control region 130A, thereby reducing at least a portion of the substrate passing through the first fluid control region 130A. In addition, the atmosphere surrounding the substrate (here, a substrate mainly composed of LiFePO4) is reduced by the H2 (see arrows AR1 and AR2 in Figure 4) supplied from the reducing gas inlet 131A, and the substrate may also be indirectly reduced through this reduced atmosphere. Thus, the "reduction process of bringing a reducing gas into contact with the substrate" in this disclosure includes not only cases in which the substrate is directly reduced by the reducing gas (here, H2), but also cases in which the substrate is indirectly reduced by the reducing gas (here, H2).

[0087] Subsequently, a carbonization process is carried out in the downstream region (second fluid control region 140A) of the intermediate section A3 (step S22). In this carbonization process, CH4 supplied from the carbonization gas inlet 141A to the second fluid control region 140A (see arrows AR3 and AR4 in Figure 4) comes into contact with the substrate after the reduction process (in this case, a substrate mainly composed of LiFePO4) that passes through the second fluid control region 140A, causing the reaction LiFePO4 + CH4 → C~LiFePO4 + 2H2 to occur, generating C~LiFePO4 and H2.

[0088] The product C~LiFePO4 generated by these steps is discharged to the outside of the reaction vessel 100 through the outlet 102 and recovered. Meanwhile, the H2 generated in step S22 is discharged to the outside of the reaction vessel 100 through the reducing gas outlet 160 and supplied back into the reaction vessel 100 through the reducing gas inlet 131A.

[0089] As described above, according to Embodiment 2, a functional substrate can be manufactured, that is, a substrate mainly composed of a compound containing at least phosphorus and a transition metal (for example, lithium iron phosphate), and containing nanocarbon (for example, one or more carbon nanotubes) grown starting from its surface.

[0090] <Embodiment 3> Next, as Embodiment 3, a reactor 10B used for manufacturing functional substrates will be described with reference to Figure 5. Figure 5 is a side view of the reactor according to Embodiment 3. Hereinafter, the reactor 10B will be described focusing on the differences from the reactor 10A of Embodiment 2. Components identical to those of the reactor 10A of Embodiment 2 will be given the same reference numerals, and their descriptions will be omitted as appropriate. For the sake of explanation, the reactor 10A of Embodiment 2 and the second reactor 10A of Embodiment 3 are depicted in a simplified manner in Figure 5.

[0091] As shown in Figure 5, the reactor 10B is constructed by combining the reactor 10 of Embodiment 1 and the reactor 10A of Embodiment 2. Hereinafter, the reactor 10 of Embodiment 1 will be referred to as the first reactor 10, and the reactor 10A of Embodiment 2 will be referred to as the second reactor 10A. Specifically, the outlet 102 of the first reactor 10 and the supply port 101 of the second reactor 10A are connected.

[0092] The first reactor 10 produces the intermediate LiFePO4.

[0093] Next, we will explain a method for producing the intermediate LiFePO4 using this reaction apparatus 10A.

[0094] First, we will explain the prerequisites for carrying out the manufacturing method of the intermediate LiFePO4.

[0095] In the following, Li3PO4 and Fe3(PO4)2·8H2O will be used as the processed materials. However, the processed materials are not limited to the above, as long as they are compounds that can produce the intermediate LiFePO4.

[0096] The heating temperature of the intermediate section A3 of the first reactor 10 is, for example, 400°C. Furthermore, H2 is supplied into the reaction vessel 100 of the first reactor 10.

[0097] The method for producing the intermediate LiFePO4 is carried out based on the above premise.

[0098] First, the materials to be processed, Li3PO4 and Fe3(PO4)2·8H2O, are supplied from the supply port 101 of the first reactor 10 to the supply port 101 side of the reaction vessel 100 of the first reactor 10. The Li3PO4 and Fe3(PO4)2·8H2O supplied to the supply port 101 side of the reaction vessel 100 are then transported by the rotating screw 120 of the first reactor 10 from the supply port 101 side of the reaction vessel 100 through the intermediate section A3 to the outlet port 102 side of the reaction vessel 100.

[0099] At that time, in the intermediate section A3 of the first reactor 10, the H2 supplied into the reaction vessel 10 of the first reactor 10 comes into contact with Li3PO4 and Fe3(PO4)2·8H2O passing through the intermediate section A3, causing a predetermined reaction to occur and generating the intermediate LiFePO4.

[0100] The generated intermediate LiFePO4 is supplied from the outlet 102 of the first reactor 10 and the supply port 101 of the second reactor 10A to the supply port 101 side of the reaction vessel 100 of the second reactor 10A.

[0101] Subsequently, the method for producing C~LiFePO4 as described in Embodiment 2 above is carried out in the second reactor 10B. This generates the product C~LiFePO4. This generated product C~LiFePO4 is discharged from the outlet 102 of the second reactor 10B to the outside of the reaction vessel 100 of the second reactor 10B and collected in the recovery unit.

[0102] As described above, according to Embodiment 3, a functional substrate can be manufactured, that is, a substrate mainly composed of a compound containing at least phosphorus and a transition metal (for example, lithium iron phosphate), and containing nanocarbon (for example, one or more carbon nanotubes) grown starting from its surface.

[0103] <Embodiment 4> Next, as Embodiment 4, the manufacturing process of a lithium-ion battery (an example of a secondary battery of this disclosure) will be described with reference to Figure 6. Figure 6 is a diagram showing the manufacturing process of a lithium-ion battery (an example of a secondary battery of this disclosure).

[0104] As shown in Figure 6, the lithium-ion battery manufacturing process includes a C-LiFePO4 manufacturing process, a mixing process, a coating process, and a lamination process, through which the lithium-ion battery is ultimately manufactured.

[0105] The C~LiFePO4 manufacturing process is a process of manufacturing C~LiFePO4 using the reaction apparatus 10A of Embodiment 2 or the reaction apparatus 10B of Embodiment 3.

[0106] The kneading process involves adding a binder to the C-LiFePO4 produced in the C-LiFePO4 process and kneading it using a twin-screw extruder or the like to produce a slurry (dispersion) containing C-LiFePO4.

[0107] The coating process involves applying a slurry containing C-LiFePO4, produced in the mixing process, to the current collector using a die coater or similar device. The current collector coated with this slurry containing C-LiFePO4 becomes the positive electrode (positive electrode material).

[0108] The lamination process involves laminating together the positive electrode (positive electrode material), electrolyte, negative electrode, etc., manufactured in the coating process, using a lamination press or similar machine.

[0109] Lithium-ion batteries are manufactured through the processes described above.

[0110] Next, we will explain the advantages of using C~LiFePO4.

[0111] Generally, in secondary batteries, carbon nanotubes are used in addition to LiFePO4 to facilitate the transfer of electrons. However, since carbon nanotubes are usually separate from LiFePO4, there are many gaps between them. Therefore, it is difficult to further facilitate the transfer of electrons.

[0112] In contrast, the C~LiFePO4 produced by the reactor 10A of Embodiment 2 or the reactor 10B of Embodiment 3 contains one or more carbon nanotubes that have grown (mainly through the carbonization process) starting from its surface (mainly the surface activated through the reduction process) (see "Products" in the lower right of Figure 4). In other words, in the C~LiFePO4 produced by the reactor 10A of Embodiment 2 or the reactor 10B of Embodiment 3, one or more carbon nanotubes are in close contact with the surface of the LiFePO4, and there is no gap between them. Therefore, when this C~LiFePO4 is used in a secondary battery, electron transfer can be made even smoother. This makes it possible to further improve the performance of the secondary battery. For example, it becomes possible to further miniaturize and increase the capacity of the secondary battery.

[0113] Furthermore, C~LiFePO4 may be applied not only as a positive electrode material for liquid-based lithium-ion batteries, but also to at least a part of the positive electrode, solid electrolyte, and intermediate layer between the positive electrode and electrolyte of all-solid-state batteries (e.g., sulfide-based all-solid-state lithium-ion batteries).

[0114] Next, I will explain some variations.

[0115] In embodiments 2 and 3 described above, examples using lithium iron phosphate as the treated material were explained, but the invention is not limited to this. For example, sodium iron phosphate may be used as the treated material. In other words, the treated material can be any base material mainly composed of a compound containing at least phosphorus and a transition metal (for example, a positive electrode active material).

[0116] The present invention has been described in detail above based on embodiments, but it goes without saying that the present invention is not limited to the embodiments already described, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0117] 10…Reaction apparatus (First reaction apparatus) 10A…Reaction apparatus (second reaction apparatus) 100…Reaction vessel 101... Supply port 102…Outlet port 110...Temperature control range 120... Screw 121... protruding part 130...First fluid control region 130A...First fluid control region 131...1st fluid inlet 131A... Gas inlet for reduction 132…1st fluid outlet 132A... Gas outlet for reduction 133...First fluid supply pipe 133A... Gas supply pipe for reduction 134...First valve 134A... Gas suction tube for reduction 140...Second fluid control region 140A...Second fluid control region 141…Second fluid inlet 141A...Gas inlet for carbonization 142…Second fluid outlet 142A...Gas outlet for carbonization 143…Second fluid supply pipe 143A...Gas supply pipe for carbonization 144...2nd valve 144A...Gas suction tube for carbonization 150…Drive unit 151...motor 152...Reducer 160... Gas outlet for reduction 161... Gas suction tube for reduction 200... Control device 201... Overall Control Unit 202...Temperature Control Unit 203...Screw rotation control unit 204...First Fluid Control Unit 205...Second Fluid Control Unit 206...IF Control Unit 207...Storage section 210...Temperature control device 230...First fluid control device 240...Second fluid control device 250... Information Input / Output Unit R10...Processed material R11...Product

Claims

1. A functional material manufacturing apparatus for producing a functional substrate in which nanocarbon is grown starting from at least a portion of the surface of a powder or granular material having an average particle diameter of 10 to 50 mm, comprising a compound containing at least phosphorus and a transition metal, A supply port for receiving the powder and granular material, and a discharge port for discharging the functional substrate, A cylindrical reaction vessel including an intermediate section between the supply port and the outlet, The aforementioned intermediate section is A reduction unit that brings the powdered material into contact with a reducing gas while conveying it from the supply port toward the discharge port, Between the reduction unit and the outlet, there is a first carbonization unit that brings the carbonization gas into contact with the granular material while flowing the carbonization gas in the opposite direction to the direction in which the granular material is conveyed, Between the first carbonization section and the outlet, there is a second carbonization section that brings the carbonization gas into contact with the powder while flowing the carbonization gas in the same direction as the direction in which the powder is conveyed, A functional substrate manufacturing apparatus comprising a reuse unit that recirculates the hydrogen generated in the first carbonization unit to the reduction unit.

2. The reduction unit is A first reduction unit that brings the reducing gas into contact with the powder while flowing the reducing gas in the opposite direction to the direction in which the powder is conveyed, The functional substrate manufacturing apparatus according to claim 1, comprising: a second reduction unit located between the first reduction unit and the outlet, which brings the reducing gas into contact with the powder or granules while flowing the reducing gas in the same direction as the direction in which the powder or granules are conveyed.

3. The aforementioned compound is lithium iron phosphate (LiFePO) 4 ) including at least, The apparatus for producing a functional substrate according to claim 1 or 2, wherein the reducing gas is hydrogen and the carbonizing gas is a lower hydrocarbon.

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