Drying device and drying method

Abstract

To provide a drying device and a drying method capable of appropriately drying an inner cavity of an outer container and an electrode group in a short time.SOLUTION: A drying device 1 includes a drying furnace 2, a pressure adjusting mechanism 4, a rotating mechanism 8, a temperature adjusting mechanism 9, and a controller 10. The drying furnace 2 accommodates a battery 100 having an outer container 101 in which a liquid injection port 102 is formed. The pressure adjusting mechanism 4 adjusts the pressure of the drying furnace 2. The rotating mechanism 8 is rotatably provided in the drying furnace, and the battery 100 is arranged in the rotating mechanism 8 with the liquid injection port 102 of the battery 100 facing the outer peripheral side. The temperature adjusting mechanism 9 can maintain the temperature of the battery 100. The controller 10 controls the operation of the pressure adjusting mechanism 4 to set the drying furnace 2 to have a reduced pressure lower than a pressure in an initial state, and controls the operation of the temperature adjusting mechanism 9 to cause the rotating mechanism 8 to rotate in a state where the temperature of the battery 100 is kept.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a drying apparatus and a drying method. [Background technology]

[0002] In the battery manufacturing process, moisture is removed from the inner cavity of the battery outer container, which has a liquid injection port, and from the electrode group housed in the inner cavity, by increasing the temperature and reducing the pressure in a drying furnace installed in the drying device. In removing the moisture as described above, i.e., drying the electrode group, the drying device is required to dry the inner cavity of the outer container and the electrode group appropriately in a short time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-198096 [Patent Document 2] Special Publication No. 2019-533126 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-192390 [Patent Document 4] Special Publication No. 2014-502025 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a drying device and a drying method that can properly dry the inner cavity of an outer container and an electrode group in a short time. [Means for solving the problem]

[0005] According to an embodiment, the drying device includes a drying oven, a pressure adjusting mechanism, a rotation mechanism, and a , warm degree adjustment mechanism ,Ko Controller and deformation mechanismThe drying oven houses a battery having an outer container with a liquid injection port formed therein. The pressure adjustment mechanism adjusts the pressure in the drying oven. The rotation mechanism is rotatably provided within the drying oven, and the battery is placed on the rotation mechanism with the liquid injection port of the battery facing the outer periphery. The temperature adjustment mechanism can maintain the temperature of the battery. The deformation mechanism is attached to the outer container. The controller controls the operation of the pressure adjustment mechanism to place the drying oven in a reduced pressure state where the pressure is lower than the initial state, and controls the operation of the temperature adjustment mechanism to rotate the rotation mechanism while maintaining the temperature of the batteries.The controller controls the operation of the pressure adjustment mechanism to place the drying oven in a reduced pressure state and then in a pressurized state where the pressure is higher than the initial state. The controller controls the operation of the deformation mechanism to deform the outer container. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic view showing an example of a drying device according to an embodiment. [Figure 2] FIG. 2 is a schematic view showing a rotation mechanism in the drying device according to the embodiment. [Figure 3] FIG. 3 is a schematic view showing the rotation mechanism in the drying device according to the embodiment, viewed from a different direction than that in FIG. [Figure 4] FIG. 4 is a graph showing an example of a change in pressure over time in a drying oven during drying in the drying device according to the embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of a process executed by a controller in a state where a battery is placed in a drying furnace in a drying device according to an embodiment. [Figure 6] FIG. 6 is a schematic view showing a deformation mechanism in a drying device according to a modified example of the embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of processing executed by a controller in a drying device according to a modified embodiment when a battery is placed in a drying furnace. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described with reference to the drawings.

[0008] FIG. 1 shows an example of a drying device 1 according to an embodiment. The drying device 1 dries the inside of an outer container 101 of a battery 100. A liquid filling port 102 is formed in the outer container 101 of the battery 100. An electrode group 103 (see FIG. 2) including a positive electrode, a negative electrode, and a separator is housed in the internal cavity of the outer container 101. The battery 100 is, for example, a lithium ion battery.

[0009] The drying apparatus 1 includes a drying oven 2, a pressure adjustment mechanism 4, a rotation mechanism 8, a temperature adjustment mechanism 9, and a controller 10. The pressure adjustment mechanism 4 includes a pressurizing mechanism 5, a decompression mechanism 6, and a pressure release mechanism 7. The pressurizing mechanism 5 is provided in the pressure adjustment mechanism 4 as a separate component from the decompression mechanism 6. The drying oven 2 is defined in a vertical direction (the direction indicated by arrows Z1 and Z2), a first horizontal direction (the direction indicated by arrows X1 and X2) that intersects (is perpendicular or substantially perpendicular to) the vertical direction, and a second horizontal direction (the direction indicated by arrows Y1 and Y2) that intersects (is perpendicular or substantially perpendicular to) both the vertical direction and the first horizontal direction.

[0010] In the drying oven 2, the batteries 100 to be dried are dried. For example, the batteries 100 are carried into the drying oven 2 through a transport path (not shown). The batteries 100 may be placed on a transport table such as a transport tray and then carried into the drying oven 2. The batteries 100 are carried into the drying oven 2 in an initial state, which will be described later. The pressure inside the drying oven 2 is adjusted by a pressure adjustment mechanism 4, which will be described later. The drying oven 2 can be sealed from the outside. It is preferable that the drying oven 2 has a shape that is resistant to pressure. The shape of the drying oven 2 is, for example, cylindrical or approximately cylindrical, or spherical or approximately spherical. However, the shape of the drying oven 2 is not limited to these. The drying oven 2 may also be placed inside a container that houses the drying oven 2.

[0011] The pressure adjustment mechanism 4 adjusts the pressure inside the drying oven 2. The pressure adjustment mechanism 4 connects the inside and outside of the drying oven 2. In this embodiment, the pressurization mechanism 5 connects the inside and outside of the drying oven 2, the decompression mechanism 6 connects the inside and outside of the drying oven 2, and the pressure release mechanism 7 connects the inside and outside of the drying oven 2.

[0012] The pressurizing mechanism 5 increases the pressure inside the drying oven 2. The configuration of the pressurizing mechanism 5 is not particularly limited as long as it is capable of increasing the pressure inside the drying oven 2. The configuration of the pressurizing mechanism 5 can be appropriately modified depending on, for example, the object to be dried. As shown in an example in FIG. 1 , the pressurizing mechanism 5 of this embodiment includes a pressure booster 51, a pressure sub-tank 52, and a valve 53. Gas for pressurizing the drying oven 2 is supplied to the pressurizing mechanism 5 from outside the pressurizing mechanism 5. The supplied gas is, for example, dry air. Valves 53 are provided between the drying oven 2 and the pressure sub-tank 52, between the pressure sub-tank 52 and the pressure booster 51, and between the pressure booster 51 and an external gas supply source. The pressurizing mechanism 5 forms a pressurization line that increases the pressure inside the drying oven 2. By driving the pressure booster 51 and opening the valve 53, the inside of the drying oven 2 is pressurized, and the pressure inside the drying oven 2 becomes higher than the pressure outside the drying oven 2 (a pressurized state). When the pressure outside the drying furnace 2 is equal to or approximately equal to atmospheric pressure, the pressure inside the drying furnace 2 is higher than atmospheric pressure.

[0013] The pressure reduction mechanism 6 reduces the pressure inside the drying oven 2. The configuration of the pressure reduction mechanism 6 is not particularly limited as long as it is capable of reducing the pressure inside the drying oven 2. The configuration of the pressure reduction mechanism 6 can be appropriately changed depending on, for example, the object to be dried. As shown in an example of FIG. 1 , the pressure reduction mechanism 6 of this embodiment includes a pressure reduction pump 61 and a valve 62. In the pressure reduction mechanism 6, the pressure reduction pump 61 is connected to the drying oven 2 via the valve 62. The pressure reduction pump 61 is connected to a valve (exhaust valve) 62. The pressure reduction mechanism 6 forms a pressure reduction line that reduces the pressure inside the drying oven 2. By driving the pressure reduction pump 61 and opening the valve 62, the pressure inside the drying oven 2 is reduced, thereby achieving a state in which the pressure inside the drying oven 2 is lower than that outside the drying oven 2 (a reduced-pressure state). When the pressure outside the drying oven 2 is equal to or approximately equal to atmospheric pressure, the pressure inside the drying oven 2 is lower than atmospheric pressure.

[0014] The pressure release mechanism 7 releases the pressure inside the drying furnace 2, thereby making the pressure inside the drying furnace 2 equal or substantially equal to the pressure outside the drying furnace 2. The configuration of the pressure release mechanism 7 is not particularly limited as long as it can make the pressure inside the drying furnace 2 equal or substantially equal to the pressure outside the drying furnace 2. The configuration of the pressure release mechanism 7 can be appropriately changed depending on, for example, the object to be dried. As shown in an example in FIG. 1 , the pressure release mechanism 7 of this embodiment includes a leak valve 71. The leak valve 71 is connected to the drying furnace 2. Opening the leak valve 71 connects the inside and outside of the drying furnace 2, so that the pressure inside the drying furnace 2 becomes equal or substantially equal to the outside. The pressure outside the drying furnace 2 is, for example, equal to or substantially equal to atmospheric pressure. In this case, opening the leak valve 71 (opening to the atmosphere) makes the pressure inside the drying furnace 2 equal to or substantially equal to atmospheric pressure (atmospheric pressure state).

[0015] 2 and 3 are schematic diagrams showing the rotation mechanism 8. In FIGS. 2 and 3, the battery 100 to be dried has been completely loaded into the rotation mechanism 8 provided inside the drying oven 2. In FIGS. 2 and 3, the vertical direction, the first horizontal direction, and the second horizontal direction are defined, as in FIG. 1. The battery 100 to be dried is placed (installed) on the rotation mechanism 8. The configuration of the rotation mechanism 8 is not particularly limited as long as it is capable of drying the battery 100 to be dried by applying centrifugal force to the battery 100. The configuration of the rotation mechanism 8 can be changed as appropriate depending on, for example, the object to be dried.

[0016] As shown in an example in FIGS. 2 and 3 , the rotation mechanism 8 includes a shaft 81 and plate portions 82 and 83. The shaft 81 extends vertically. The plate portions 82 and 83 are spaced apart from each other in the vertical direction. A gap is formed between the plate portions 82 and 83. Batteries 100 to be dried are placed in this gap. The plate portions 82 and 83 are formed, for example, in a disk or approximately disk shape. In one example, multiple batteries 100 are placed on the plate portion 82, and the plate portion 83 is placed on an outer container 101 for the multiple batteries 100. In this way, the batteries 100 are held on the plate portion 82. The thicknesses of the plate portions 82 and 83 are not particularly limited as long as they can appropriately hold the batteries 100 to be dried. The first horizontal size and the second horizontal size of the plate portions 82 and 83 can be changed as appropriate depending on the size, shape, number, etc. of the batteries 100 to be placed.

[0017] In the rotation mechanism 8, the plate portion 82 and the plate portion 83 are rotatable around the central axis C of the shaft portion 81. In the rotation mechanism 8, the plate portion 82 and the plate portion 83 rotate, for example, in the direction of arrow R1 by driving a driving member (not shown), such as an electric motor. As shown in FIG. 3 , multiple batteries 100 are arranged between the plate portion 82 and the plate portion 83 with the liquid filling ports 102 of the batteries 100 facing the outer periphery of the rotation mechanism 8. In the example shown in FIG. 3 , eight batteries 100 are arranged on the plate portion 82 with the liquid filling ports 102 facing the outer periphery of the rotation mechanism 8. Note that, although one plate portion 82 and one plate portion 83 are provided in FIG. 3 , this is not limiting. That is, multiple pairs of plate portions 82 and 83 may be arranged in the rotation mechanism 8 at positions offset from each other in the vertical direction. In this case, the multiple pairs of plate portions 82 and 83 are rotatable around the central axis C of the shaft portion 81. Therefore, the plurality of pairs of plate portions 82 and plate portions 83 are arranged concentrically or approximately concentrically with one another in the rotation mechanism 8.

[0018] The rotation mechanism 8 applies centrifugal force to the battery 100 by rotating at a predetermined rotation speed. The rotation speed of the rotation mechanism 8 can be adjusted appropriately depending on the object to be dried. In one example, the rotation speed of the rotation mechanism 8 is approximately 10 to 1000 rotations per minute. As described above, the rotation mechanism 8 is arranged such that the liquid filling port 102 of the battery 100 faces the outer periphery of the rotation mechanism 8. Therefore, when the rotation mechanism 8 applies centrifugal force to the battery 100, at least one of the liquid (moisture) present in the internal cavity of the battery 100 and the vaporized gas of the liquid is discharged from the liquid filling port 102.

[0019] As shown in FIG. 1 , the liquid inlet 102 of the battery 100 disposed in the rotation mechanism 8 is connected to a three-way valve 84. The three-way valve 84 is connected to a pressurizing mechanism 5 and a decompression mechanism 6. In this embodiment, the pressure in the internal cavity of the battery 100 is increased by driving the pressure booster 51 and opening the valve 53 and the three-way valve 84, thereby increasing the pressure in the internal cavity of the battery 100. When the pressure in the internal cavity of the drying oven 2 is equal to or substantially equal to atmospheric pressure, the pressure in the internal cavity of the battery 100 is increased by more than atmospheric pressure. Furthermore, the pressure in the internal cavity of the battery 100 is decreased by driving the decompression pump 61 and opening the valve 62 and the three-way valve 84, thereby decreasing the pressure in the internal cavity of the battery 100. When the pressure in the internal cavity of the drying oven 2 is equal to or substantially equal to atmospheric pressure, the pressure in the internal cavity of the battery 100 is decreased by more than atmospheric pressure.

[0020] It is preferable that the pressurization of the internal cavity of the battery 100 by the pressurization mechanism 5 and the depressurization of the internal cavity of the battery 100 by the depressurization mechanism 6 are performed at or below a threshold value that is a criterion for starting plastic deformation of the outer casing 101 of the battery 100. In other words, the pressure adjustment mechanism 4 pressurizes or depressurizes the internal cavity of the battery 100 within a range that causes elastic deformation of the outer casing 101 of the battery 100. The threshold value that is a criterion for starting plastic deformation of the outer casing 101 may be calculated by measurement, may be determined by performing a simulation, or may be determined by analytical calculation.

[0021] In this embodiment, the threshold value that serves as the reference for when the pressure adjustment mechanism 4 starts to plastically deform the outer container 101 is set, for example, as follows: First, the initial dimensions of the outer container 101 are measured. Next, the pressurizing mechanism 5 is activated, and the internal cavity of the outer container 101 is continuously pressurized for 10 seconds at a pressure of 0 MPa or more and 0.3 MPa or less. After the pressurization is completed, the post-deformation dimensions of the outer container 101 are measured. Next, the initial and post-deformation dimensions of the outer container 101 are measured in the same manner, except that the internal cavity of the outer container 101 is continuously pressurized for 20 seconds. Next, the initial and post-deformation dimensions of the outer container 101 are measured in the same manner, except that the internal cavity of the outer container 101 is continuously pressurized for 30 seconds. From these initial and post-deformation dimensions, a threshold value that serves as the reference for when the outer container 101 starts to plastically deform is set. 。

[0022] The temperature adjustment mechanism 9 adjusts the temperature of the drying oven 2. The configuration of the temperature adjustment mechanism 9 is not particularly limited as long as it is configured to adjust the temperature inside the drying oven 2. The configuration of the temperature adjustment mechanism 9 can be changed appropriately depending on, for example, the object to be dried. The temperature adjustment mechanism 9 is, for example, a heater. In this embodiment, the temperature adjustment mechanism 9 adjusts the temperature of the drying oven 2 to a temperature that promotes the removal of moisture contained in the internal cavity of the battery 100 from the internal cavity. In one example, the temperature adjustment mechanism 9 adjusts the temperature of the drying oven 2 to about 95°C. By adjusting the temperature of the drying oven 2 by the temperature adjustment mechanism 9, the temperature of the battery 100 placed inside the drying oven 2 also becomes approximately the same as the temperature of the drying oven 2.

[0023] The controller 10 is, for example, a computer. The controller 10 includes a processor or integrated circuit (control circuit) including a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), and a storage medium such as a memory. The controller 10 may include one integrated circuit or a plurality of integrated circuits. The controller 10 performs processing by executing a program stored in a storage medium or the like. The controller 10 controls pressurization, depressurization, and pressure release by the pressure adjustment mechanism 4 (pressurization mechanism 5, depressurization mechanism 6, and pressure release mechanism 7), operation of the rotation mechanism 8, operation of the temperature adjustment mechanism 9, etc.

[0024] The drying device 1 may be provided with a user interface. The user interface includes an operating member. An operator or the like inputs commands related to the operation of the drying device 1 through the operating member. Examples of the operating member include a button, a dial, and a touch panel. The user interface may also include a notification unit that notifies the operator or the like of information. The notification unit notifies the operator or the like by displaying a screen, emitting a sound, turning on a light, etc. The notification unit notifies, for example, information that needs to be recognized by the operator, warning information to the operator, etc.

[0025] Fig. 4 is a schematic diagram showing an example of the change over time (pressure profile) of the pressure in the drying oven 2 during drying. In Fig. 4, the horizontal axis represents the elapsed time from the start of pressure adjustment of the drying oven 2 by the pressure adjustment mechanism 4, and the vertical axis represents the pressure in the drying oven 2. Line α represents the change over time of the pressure in the drying oven 2, i.e., the pressure profile.

[0026] In the example of FIG. 4 , pressures p0, p1, and p2 are defined. Pressure p0 is the pressure in the drying oven 2 when the pressure adjustment mechanism 4 begins to adjust the pressure in the drying oven 2 (initial state). Pressure p0, which is the pressure in the initial state, is, for example, the pressure at the time when the battery 100 is carried in through a transport path (not shown) (or placed on a transport table such as a transport tray) and housed in the drying oven 2, i.e., atmospheric pressure. Pressure p1 is the lower limit pressure of the drying oven 2 when adjusted by the pressure adjustment mechanism 4. The lower limit pressure is preferably, for example, −98 kPa or more and −10 kPa or less, based on pressure p0. When pressure p0 is atmospheric pressure, the lower limit pressure is preferably −98 kPa or more and −10 kPa or less in gauge pressure. Pressure p2 is the upper limit pressure of the drying oven 2 when adjusted by the pressure adjustment mechanism 4. The upper limit pressure is preferably, for example, 0.2 MPa or more and 4.0 MPa or less. The upper limit pressure is equal to or less than the design pressure of the drying furnace 2. A state in which the pressure in the drying furnace 2 is higher than pressure p0 is defined as a pressurized state, and a state in which the pressure in the drying furnace 2 is lower than pressure p0 is defined as a reduced pressure state.

[0027] 4, before time t0, the battery 100 is carried into the drying oven 2, the rotation mechanism 8 with the battery 100 placed in a predetermined position starts to rotate, and the temperature adjustment mechanism 9 starts to adjust the temperature of the drying oven 2. That is, after time t0, the battery 100 continues to be rotated by the rotation mechanism 8, and the temperature of the drying oven 2 is adjusted to a predetermined temperature by the temperature adjustment mechanism 9.

[0028] At time t0, the pressure adjustment mechanism 4 begins adjusting the pressure in the drying oven 2. The pressure in the drying oven 2 is reduced to pressure p1 by the pressure adjustment mechanism 4 (pressure reduction mechanism 6) between time t0 and time t1. For example, the pressure in the drying oven 2 monotonically decreases between time t0 and time t1. When the pressure in the drying oven 2 reaches p1 at time t1, the pressure in the drying oven 2 is released to pressure p0 by the pressure adjustment mechanism 4 (pressure release mechanism 7) between time t1 and time t2. For example, the pressure in the drying oven 2 monotonically increases between time t1 and time t2. Thus, in the pressure profile shown in FIG. 4, the drying oven 2 is maintained in a reduced-pressure state between time t0 and time t2.

[0029] While the drying oven 2 is maintained in a reduced pressure state, the pressure in the internal cavity of the battery 100 is varied by the pressure adjustment mechanism 4. That is, the pressure in the internal cavity of the battery 100 is adjusted to a pressure different from the pressure in the drying oven 2. In one example, the three-way valve 84 connected to the pressurizing mechanism 5 is opened and the internal cavity of the battery 100 is pressurized by the pressurizing mechanism 5, thereby increasing the pressure in the internal cavity of the battery 100. In another example, the three-way valve 84 connected to the decompression mechanism 6 is opened and the internal cavity of the battery 100 is decompressed by the decompression mechanism 6, thereby decreasing the pressure in the internal cavity of the battery 100. As a result, the air in the internal cavity of the battery 100 is replaced with the air in the drying oven 2.

[0030] After the pressure in the drying oven 2 reaches pressure p0 at time t2, the pressure in the drying oven 2 is increased to pressure p2 by the pressure adjustment mechanism 4 (pressurization mechanism 5) between time t2 and time t3. Between time t2 and time t3, for example, the pressure in the drying oven 2 increases monotonically. Between time t2 and time t3, the internal cavity of the battery 100 is dried, similar to the period between time t1 and time t2. Between time t2 and time t3, the pressure inside the drying oven 2 is higher than between time t1 and time t2.

[0031] When the pressure in the drying oven 2 reaches p2 at time t3, the pressure adjustment mechanism 4 begins to reduce the pressure in the drying oven 2. The pressure inside the drying oven 2 is reduced to pressure p0 by the pressure adjustment mechanism 4 (pressure release mechanism 7) between time t3 and time t4. For example, the pressure inside the drying oven 2 monotonically decreases between time t3 and time t4. At time t4, the pressure inside the drying oven 2 reaches p0. Thus, in the pressure profile shown in FIG. 4 , the drying oven 2 is maintained in a pressurized state between time t2 and time t4. Even when the drying oven 2 is maintained in a pressurized state, the pressure in the internal cavity of the battery 100 is varied by the pressure adjustment mechanism 4, similar to the state when the drying oven 2 is maintained in a reduced pressure state. This causes the air in the internal cavity of the battery 100 to be replaced with the air in the drying oven 2.

[0032] As described above, in the pressure profile shown in Fig. 4, the drying oven 2 is first depressurized using the pressure adjustment mechanism 4 (pressurization mechanism 5, depressurization mechanism 6, and pressure release mechanism 7), the rotation mechanism 8, and the temperature adjustment mechanism 9, and then pressurized beyond the initial pressure p0, and then returned to the initial state. Furthermore, the pressure adjustment mechanism 4 varies the pressure in the internal cavity of the battery 100 in both the depressurized and pressurized states. This allows moisture to sufficiently evaporate from the battery 100 placed inside the drying oven 2, for example, thereby drying the battery 100.

[0033] Thus, in the pressure profile of the drying apparatus 1, the pressure in the drying oven 2 is reduced from the initial pressure p0 and then returned to the initial pressure p0 by releasing the pressure. Thereafter, the pressure in the drying oven 2 is increased from the initial pressure p0 and then returned to the initial pressure p0 by releasing the pressure. In other words, the pressure profile includes a reduced pressure state transition in which the pressure transitions from the initial pressure state to the initial pressure state via a reduced pressure state, and a pressurized state transition in which the pressure transitions from the initial pressure state to the initial pressure state via a pressurized state. Note that the pressure profile may include one or more reduced pressure state transitions and one or more pressurized state transitions.

[0034] In one example, the controller 10 may control the pressure adjustment mechanism 4 (the pressurization mechanism 5, the depressurization mechanism 6, and the pressure release mechanism 7) based on the elapsed time in the reduced pressure state and the elapsed time in the pressurized state. In this case, the time during which the pressure inside the drying oven 2 is in the reduced pressure state and / or the pressurized state is a predetermined time that has been set in advance. The controller 10 maintains the pressure at which the drying oven 2 is in the reduced pressure state for a predetermined time. The controller 10 also maintains the pressure at which the drying oven 2 is in the pressurized state for a predetermined time. In either the reduced pressure state or the pressurized state, the controller 10 appropriately changes the pressure in the drying oven 2 after the predetermined time has elapsed.

[0035] 5 shows a process executed by the controller 10 when the battery 100 to be dried is transported to the drying oven 2. FIG. 5 is an example of a process executed by the controller 10 in the pressure profile shown in FIG. 4. The process in FIG. 5 is executed by the controller 10 every time a drying operation is performed in the drying device 1. Therefore, the process in FIG. 5 shows an example of a process executed in one drying operation by the drying device 1.

[0036] In the case of the process shown in FIG. 5, i.e., the process corresponding to the pressure profile shown in FIG. 4, in the drying apparatus 1, the controller 10 controls the drive unit that drives the rotation mechanism 8 to rotate the rotation mechanism 8 at a predetermined rotation speed (S101). The controller 10 also controls the temperature adjustment mechanism 9 to adjust the temperature of the drying oven 2 to a predetermined temperature (S101). The controller 10 controls the pressure adjustment mechanism 4 (depressurization mechanism 6) to transition the drying oven 2 to a depressurized state (S102). The controller 10 controls the pressure adjustment mechanism 4 (pressurization mechanism 5 and depressurization mechanism 6) and the three-way valve 84 to vary the pressure in the internal cavity of the battery 100 (S103). The controller 10 controls the pressure adjustment mechanism 4 (pressure release mechanism 7) to transition the drying oven 2 to the start state (S104).

[0037] 4, the drying oven 2 transitions to the pressurized state following the transition to the initial state. Therefore, the controller 10 controls the pressure adjustment mechanism 4 (pressurization mechanism 5) to transition the drying oven 2 to the pressurized state (S105). The controller 10 controls the pressure adjustment mechanism 4 (pressurization mechanism 5 and depressurization mechanism 6) and the three-way valve 84 to vary the pressure in the internal cavity of the battery 100 (S106). The controller 10 controls the pressure adjustment mechanism 4 (pressure release mechanism 7) to transition the drying oven 2 to the initial state (S107).

[0038] After the process of S107, the controller 10 determines whether the drying device 1 satisfies the termination condition (S108). If the drying device 1 does not satisfy the termination condition (S108-No), the controller 10 sequentially performs the processes from S102 onwards. If the drying device 1 satisfies the termination condition (S108-Yes), the controller 10 controls the drive unit that drives the rotation mechanism 8 to stop the rotation of the rotation mechanism 8 (S109). The controller 10 also controls the temperature adjustment mechanism 9 to end the temperature adjustment of the drying oven 2 (S109). This completes the drying of the battery 100 by the drying device 1. The pressure profile shown in FIG. 4 corresponds to the pressure profile when the process progresses from S101 and the controller 10 determines in the process of S108 that the termination condition is satisfied. In one example, the termination condition is that the pressurized state continues for a predetermined time.

[0039] As described above, in this embodiment, the drying apparatus 1 includes a drying furnace 2, a pressure adjustment mechanism 4, a rotation mechanism 8, a temperature adjustment mechanism 9, and a controller 10. The drying furnace 2 accommodates an outer container 101 having a liquid inlet 102 and a battery 100 including an electrode group 103 housed in the internal cavity of the outer container 101. The pressure adjustment mechanism 4 adjusts the pressure in the drying furnace 2. The rotation mechanism 8 is rotatably provided within the drying furnace 2, and the battery 100 is placed on the rotation mechanism 8 with the liquid inlet 102 of the battery 100 facing the outer periphery. The temperature adjustment mechanism 9 can maintain the temperature of the battery 100. The controller 10 controls the operation of the pressure adjustment mechanism 4 to place the drying furnace 2 in a reduced pressure state lower than the initial state, and controls the operation of the temperature adjustment mechanism 9 to rotate the rotation mechanism 8 while maintaining the temperature of the battery 100, thereby applying centrifugal force to the battery 100. As a result, the internal cavity of the outer container 101 of the battery 100 is appropriately dried as described above. Therefore, the drying device 1 of this embodiment can appropriately dry the inner cavity of the outer container 101 and the electrode group 103 arranged in the inner cavity in a short time.

[0040] In this embodiment, the controller 10 preferably controls the operation of the pressure adjustment mechanism 4 to place the drying furnace 2 in a reduced pressure state and then in a pressurized state where the pressure is higher than the initial state. This causes the pressure inside the drying furnace 2 to fluctuate as described above, and also causes the pressure in the internal cavity of the battery 100 placed inside the drying furnace 2 to fluctuate. This widens the gap between the positive electrode, negative electrode, and separator that constitute the electrode group 103 placed in the internal cavity, thereby accelerating drying of the electrode group 103. Therefore, the drying device 1 can achieve high drying efficiency, and can appropriately dry the internal cavity of the outer container 101, which is the target to be dried, and the electrode group 103 placed in the internal cavity, in a short period of time.

[0041] In this embodiment, the pressure adjustment mechanism 4 preferably adjusts the pressure inside the outer container. Furthermore, the controller 10 preferably controls the operation of the pressure adjustment mechanism 4 to adjust the pressure inside the outer container 101 to a pressure different from the pressure inside the drying furnace 2. This generates a pressure difference between the pressure inside the drying furnace 2 and the pressure inside the outer container 101, as described above. This promotes gas exchange between the internal cavity of the outer container 101 and the inside of the drying furnace 2. Therefore, the drying device 1 can achieve high drying efficiency, and can appropriately dry the internal cavity of the outer container 101 and the electrode group 103 arranged in the internal cavity, which are the drying targets, in a short period of time.

[0042] (Variation) FIG. 6 is a schematic diagram showing an example of a deformation mechanism 11 that deforms the outer casing 101 of the battery 100. In this modification, instead of or in addition to varying the pressure in the internal cavity of the battery 100 via the three-way valve 84, the deformation mechanism 11 varies the size of the internal cavity of the battery 100. The operation of the deformation mechanism 11 is controlled by a controller 10. The deformation mechanism 11 is attached to the outer casing 101 of the battery 100 and includes pads 12 and 13 that apply an external force to the outer casing 101 of the battery 100. The pads 12 and 13 are attached to the outer casing from the outside with the outer casing sandwiched between them. The outer casing 101 is deformed by the pads 12 and 13, thereby changing the size of the internal cavity of the battery 100. A force toward the internal cavity of the outer container 101, i.e., a force pushing the outer container 101 inward, is applied to the outer container 101 from the pads 12 and 13, thereby reducing the size of the internal cavity of the battery 100. A force pulling the outer container 101 outward is applied to the outer container 101, thereby increasing the size of the internal cavity of the battery 100.

[0043] The deformation mechanism 11 is preferably formed from a material having the same or approximately the same thermal conductivity as the outer container 101. In one example, the thermal conductivity of the material forming the deformation mechanism 11 is 16.0 W / m·K or higher. By forming the deformation mechanism 11 from a material with such thermal conductivity, a decrease in the temperature of the outer container 101 due to the deformation mechanism 11 being attached to the outer container 101 can be suppressed.

[0044] In this modification, the pads 12 and 13 are, for example, suction pads. The pads 12 and 13 are connected to a pressure adjustment mechanism 4 (a pressurizing mechanism 5, a decompression mechanism 6, and a pressure release mechanism 7). When the pressure acting on the pads 12 and 13 is increased by the pressurizing mechanism 5, a force that pushes the outer container 101 inward is applied, thereby reducing the size of the internal cavity of the battery 100. When the pressure acting on the pads 12 and 13 is reduced by the decompression mechanism 6, a force that pulls the outer container 101 outward is applied, thereby increasing the size of the internal cavity of the battery 100. The pads 12 and 13 may be driven by a driving unit (not shown) to deform the outer container 101.

[0045] The magnitude of the force applied to the outer container 101 by the deformation mechanism 11 is equal to or less than a threshold value that serves as a criterion for the start of plastic deformation of the outer container 101. In other words, it is preferable that the deformation mechanism 11 applies to the outer container 101 a force that deforms the outer container 101 within a range in which the outer container 101 elastically deforms. The threshold value that serves as a criterion for the start of plastic deformation of the outer container 101 can be set appropriately depending on the material of the outer container 101, etc. The threshold value that serves as a criterion for the start of plastic deformation of the outer container 101 may be calculated by measurement, may be determined by performing a simulation, or may be determined by analytical calculation.

[0046] In this modified example, the threshold value that serves as the reference for when the pads 12, 13 begin to plastically deform the outer container 101 is set, for example, as follows: First, the initial dimensions of the outer container 101 are measured. Next, the pads 12, 13 are attached to the outer container 101. The pressure reducing mechanism 6 is activated to set the pressure acting on the pads 12, 13 to between 0 MPa and 0.3 MPa, and the outer container 101 is pulled outward for 10 seconds. After the pads 12, 13 are removed from the outer container 101, the post-deformation dimensions of the outer container 101 are measured. Next, the initial and post-deformation dimensions of the outer container 101 are measured in the same manner, except that the outer container 101 is pulled outward for 20 seconds. Next, the initial and post-deformation dimensions of the outer container 101 are measured in the same manner, except that the outer container 101 is pulled outward for 30 seconds. From these initial and post-deformation dimensions, a threshold value that serves as the reference for when the outer container 101 begins to plastically deform is set. 。

[0047] Fig. 7 shows the process executed by the controller 10 in the modified example. In the process shown in Fig. 7, the processes of S201, S202, S204, S205, and S207 to S209 are the same as the processes of S101, S102, S104, S105, and S107 to S109 shown in Fig. 5. That is, in the process shown in Fig. 7, the processes of S203 and S206 are different from the process shown in Fig. 5.

[0048] In the process shown in FIG. 7, after completing the process of S202, the controller 10 controls the deformation mechanism 11 to deform the outer container 101 within a range that does not cause plastic deformation, as described above (S203). The controller 10 sequentially performs the processes of S204 and S205. After completing the process of S205, the controller 10 controls the deformation mechanism 11 to deform the outer container 101 within a range that does not cause plastic deformation, as described above (S206). The controller 10 performs the processes from S207 onwards, as described above. This completes the drying of the battery 100 by the drying device 1.

[0049] In this modified example, the drying apparatus 1 preferably includes a deformation mechanism 11. The deformation mechanism 11 is attached to the outer container 101, and in particular, preferably includes pads attached to the outer container 101 from the outside while sandwiching the outer container 101. The controller 10 preferably controls the operation of the deformation mechanism 11 to deform the outer container 101 to a value equal to or less than a threshold value at which the outer container 101 begins to undergo plastic deformation. This causes the outer container 101 to deform within a range that does not cause plastic deformation. As a result, the size of the internal cavity of the outer container 101 fluctuates. This promotes gas exchange between the internal cavity of the outer container 101 and the interior of the drying furnace 2. Therefore, the drying apparatus 1 can achieve high drying efficiency, thereby appropriately drying the internal cavity of the outer container 101 and the electrode group 103 arranged in the internal cavity, which are the drying targets, in a short period of time. Furthermore, in this modified example, the drying apparatus 1 has the same configuration as the above-described embodiment, and therefore achieves the same effects as the above-described embodiment.

[0050] In another example, gas present inside the drying furnace 2 may be injected into the internal cavity of the outer container 101 through a liquid inlet 102 formed in the outer container 101, or gas may be discharged from the internal cavity of the outer container 101 into the drying furnace 2. For example, the size of the internal cavity of the outer container 101 is increased by forcibly injecting dry air into the internal cavity of the outer container 101 through the liquid inlet 102. Meanwhile, the size of the internal cavity of the outer container 101 is reduced by forcibly discharging gas present in the internal cavity of the outer container 101 through the liquid inlet 102. This makes it possible to change the size of the internal cavity of the outer container 101 and to replace the gas in the internal cavity of the outer container 101 with the injected dry air. Therefore, the internal cavity of the outer container 101 to be dried and the electrode group 103 arranged in the internal cavity can be appropriately dried in a short time.

[0051] The drying apparatus of at least one of these embodiments includes a drying oven, a pressure adjustment mechanism, a rotation mechanism, a temperature adjustment mechanism, and a controller. The rotation mechanism is rotatably provided within the drying oven, and batteries are placed on the rotation mechanism with their electrolyte inlets facing the outer periphery. The controller controls the operation of the pressure adjustment mechanism to reduce the pressure in the drying oven to a reduced pressure state lower than the initial state, and controls the operation of the temperature adjustment mechanism to rotate the rotation mechanism while maintaining the temperature of the batteries. This provides a drying apparatus and a drying method that can properly dry the internal cavity of the outer container and the electrode group in a short period of time.

[0052] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. The following are additional notes. [1] A drying furnace that accommodates a battery having an outer container formed with a liquid injection port; a temperature adjustment mechanism capable of maintaining the temperature of the battery; a pressure adjustment mechanism for adjusting the pressure of the drying oven; a rotation mechanism that is rotatably provided in the drying furnace and on which the battery is placed with the liquid injection port of the battery facing the outer periphery; a controller that controls the operation of the pressure adjustment mechanism to place the drying furnace in a reduced pressure state lower than the initial state, and controls the operation of the temperature adjustment mechanism to rotate the rotation mechanism while maintaining the temperature of the battery; A drying device comprising: [2] The controller controls the operation of the pressure adjustment mechanism to bring the drying furnace into the reduced pressure state and then into a pressurized state in which the pressure is higher than the initial state. [1] The drying device according to the present invention. [3] The pressure adjustment mechanism adjusts the pressure inside the outer container, the controller controls the operation of the pressure adjustment mechanism to adjust the pressure inside the outer container to a pressure different from the pressure inside the drying oven. [1] or [2]. The drying device according to [1] or [2]. [4] A deformation mechanism attached to the outer container is provided, the controller controls the operation of the deformation mechanism to deform the outer container. The drying device according to any one of [1] to [3]. [5] Placing a battery having an outer container formed with a liquid injection port in a drying oven; placing the battery in the drying furnace with the injection port facing the outer periphery; rotating the battery with the injection port facing the outer periphery while maintaining the temperature of the battery and adjusting the pressure of the drying furnace to a reduced pressure state lower than the initial state; A drying method comprising: [Explanation of symbols]

[0053] 1...drying device, 2...drying furnace, 4...pressure adjustment mechanism, 5...pressurization mechanism, 6...decompression mechanism, 7...pressure release mechanism, 8...rotation mechanism, 9...temperature adjustment mechanism, 10...controller, 11...deformation mechanism, 12, 13...pad, 100...battery, 101...outer container, 102...filling port, electrode group...103.

Claims

1. a drying furnace that accommodates a battery having an outer container formed with a liquid filling port; a temperature adjustment mechanism capable of maintaining the temperature of the battery; a pressure adjustment mechanism for adjusting the pressure of the drying oven; a rotation mechanism that is rotatably provided in the drying furnace and on which the battery is placed with the liquid injection port of the battery facing the outer periphery; a controller that controls the operation of the pressure adjustment mechanism to place the drying furnace in a reduced pressure state lower than the initial state, and controls the operation of the temperature adjustment mechanism to rotate the rotation mechanism while maintaining the temperature of the battery; a deformation mechanism attached to the outer container; Equipped with the controller controls the operation of the pressure adjustment mechanism to bring the drying furnace into the reduced pressure state and then into a pressurized state in which the pressure is higher than the initial state, and controls the operation of the deformation mechanism to deform the outer container. drying equipment.

2. the pressure adjustment mechanism adjusts the pressure inside the outer container; the controller controls the operation of the pressure adjustment mechanism to adjust the pressure inside the outer container to a pressure different from the pressure inside the drying oven. The drying device according to claim 1 .

3. placing a battery having an outer container formed with a liquid filling port in a drying oven; placing the battery in the drying furnace with the injection port facing the outer periphery; rotating the battery with the injection port facing the outer periphery while maintaining the temperature of the battery and adjusting the pressure of the drying furnace to a reduced pressure state lower than the initial state; After the drying furnace is brought into the reduced pressure state, the pressure is adjusted to a pressurized state higher than the initial state; deforming the outer container by controlling the operation of a deformation mechanism attached to the outer container; A drying method comprising:

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