Surface pressure application mechanism

Abstract

To provide a surface pressure application mechanism which can be miniaturized.SOLUTION: A surface pressure application mechanism for applying a surface pressure to a stack of an all-solid-state battery in a stacking direction includes: first and second support parts which are located in the stacking direction relative to the stack to support the stack; a fixed part for fixing the first and second support parts; and a spring and a hydraulic chamber which are located between the first and second support parts and connect the first and second support parts. When one of the first and second support parts is in a movable state where a load is applied to the one support part and the one support part is movable in the stacking direction, the other of the first and second support parts is in a fixed state where the other support part is fixed so as not to move even if a load is applied thereto. The first and second support parts can be switched between the movable state and the fixed state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface pressure applying mechanism. [Background technology]

[0002] A load-applying device is known that is configured to apply a restraint load to the energy storage module using a predetermined number of elastic bodies in a first form, and to apply a restraint load to the energy storage module using more than the predetermined number of elastic bodies in a second form, and to switch from the first form to the second form depending on deterioration over time, etc. (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-114625 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, in order to apply an appropriate load to the all-solid-state battery over a long period of time, it is necessary to provide another elastic body in the device that is not used before the elastic body deteriorates but is used after the elastic body deteriorates, which causes a problem that the entire device becomes large.

[0005] The problem to be solved by the present invention is to provide a surface pressure applying mechanism that can be made compact. [Means for solving the problem]

[0006] The present invention provides a surface pressure applying mechanism that applies surface pressure to a stack of an all-solid-state battery in a stacking direction, and includes first and second support parts that are positioned relative to the stack in the stacking direction and support the stack, a fixing part for fixing the first and second support parts, and a spring and hydraulic chamber that are positioned between the first and second support parts and connect the first and second support parts, and one of the first and second support parts is in a movable state where it can move in the stacking direction when it receives a load, and the other is in a fixed state where it is fixed to the fixing part so that it will not move even when it receives a load, and the above-mentioned problem is solved by the first and second support parts being switchable between the movable state and the fixed state. [Effects of the Invention]

[0007] According to the present invention, the surface pressure applying mechanism can be made smaller. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view schematically showing a battery module including a surface pressure applying mechanism according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partial front view showing an example of a surface pressure applying mechanism according to this embodiment. [Figure 3] FIG. 3 is a diagram for explaining an example of the movement operation of the first support part in the surface pressure applying mechanism according to the present embodiment. [Figure 4] FIG. 4 is a diagram for explaining an example of the movement operation of the second support part in the surface pressure applying mechanism according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A surface pressure applying mechanism according to an embodiment of the present invention will be described with reference to the drawings. The surface pressure applying mechanism according to this embodiment is provided in a battery module of a lithium deposition-type all-solid-state battery. The battery module is installed as a battery in a vehicle such as an electric vehicle.

[0010] FIG. 1 is a front view schematically showing a battery module including a surface pressure applying mechanism according to an embodiment of the present invention. As shown in FIG. 1, the battery module 1 includes a stack 10 formed by stacking a plurality of all-solid-state batteries, a surface pressure applying mechanism 20, and an exterior member 30. In FIG. 1, the X-axis is the stacking direction in which the all-solid-state batteries are stacked. The Y-axis is the surface direction of the all-solid-state batteries, and is perpendicular to the X-axis. The battery module 1 is not limited to one, and multiple battery modules 1 may be provided.

[0011] The thickness of the laminate 10 in the stacking direction changes as the laminate 10 expands and contracts due to charging and discharging. The all-solid-state battery is not particularly limited, but for example, is configured by stacking a negative electrode layer, a negative electrode current collector foil, a solid electrolyte layer, a positive electrode layer, and a positive electrode current collector foil in the stacking direction (X-axis direction).

[0012] The negative electrode layer is an alkali metal layer mainly composed of alkali metal that is released from the positive electrode layer, reaches the negative electrode current collector foil through the solid electrolyte layer, and deposits thereon as the all-solid-state battery is charged. The negative electrode layer is a layer that deposits on the negative electrode current collector foil during charging of the all-solid-state battery, increasing in volume and decreasing in volume during discharge. The negative electrode layer is, for example, a lithium metal layer. The negative electrode layer may include a layer other than the lithium metal layer, for example, an auxiliary layer that assists the deposition of the lithium metal layer. The negative electrode current collector foil is a foil-like member having electrical conductivity. The negative electrode current collector foil is, for example, a metal foil, and an example of this metal foil is copper foil. The negative electrode current collector foil may be made of an electrically conductive resin. The negative electrode current collector foil is joined to a negative electrode tab (not shown).

[0013] The solid electrolyte layer may be, for example, a sulfide solid electrolyte or an oxide solid electrolyte, with a sulfide solid electrolyte being preferred. The positive electrode layer contains at least a positive electrode active material capable of absorbing and releasing lithium (Li). While not particularly limited, it preferably contains a sulfur-containing positive electrode active material. The sulfur-containing positive electrode active material may be any material capable of absorbing and releasing lithium ions during charging and utilizing the sulfur oxidation-reduction reaction during discharging. The type of sulfur-containing positive electrode active material is not particularly limited, but particles or thin films of elemental sulfur (S), organic sulfur compounds, or inorganic sulfur compounds may be used. The positive electrode current collector foil is a conductive foil-like member. The positive electrode current collector foil is, for example, a metal foil, such as copper foil. The positive electrode current collector foil may be made of a conductive resin. The positive electrode current collector foil is bonded to a positive electrode tab (not shown).

[0014] The surface pressure applying mechanism 20 applies a compressive load to the laminate 10 in the stacking direction (X-axis direction) to apply a surface pressure. Specifically, the surface pressure applying mechanism 20 functions to maintain a surface pressure equal to or greater than a predetermined value in accordance with the expansion and contraction of the laminate 10. The surface pressure applying mechanism 20 includes a first support portion 21, a second support portion 22, a fixing portion 23, and a connecting portion 24. The first support portion 21 and the second support portion 22 are positioned relative to the laminate 10 in the stacking direction to support the laminate 10. That is, in the surface pressure applying mechanism 20, the first support portion 21 and / or the second support portion 22 receive a load applied in the stacking direction due to the expansion and contraction of the laminate 10 and maintain the surface pressure applied to the laminate 10. Details of each component constituting the surface pressure applying mechanism 20 will be described later. Note that in this embodiment, the direction in which the first support portion 21 and the second support portion 22 are positioned relative to the laminate 10 in the stacking direction (X-axis direction) is defined as downward, and the direction opposite to downward relative to the laminate 10 is defined as upward. That is, the +X axis direction is upward, and the −X axis direction is downward.

[0015] The exterior member 30 is a member having a substantially rectangular parallelepiped shape, and houses the stack 10 and the surface pressure applying mechanism 20 inside. The stack 10 is compressed and stored inside the exterior member 30 by the surface pressure applying mechanism 20. The exterior member 30 is not particularly limited, but for example, a metal case can be used. The exterior member 30 has an upper surface 31 and a lower surface 32 that face each other in the stacking direction, and surfaces extending from each side of the upper surface 31 in a direction substantially perpendicular to the upper surface 31 (X-axis direction) are defined as side surfaces that constitute the exterior member 30. Of the side surfaces that constitute the exterior member 30, side surfaces 33 and 34 face each other in the Y-axis direction.

[0016] The laminate 10 has an upper surface 11 and a lower surface 12 located opposite the upper surface 11. The laminate 10 is stored so that the upper surface 11 contacts the upper surface 31 on the inside of the exterior member 30. Inside the exterior member 30, a first support portion 21, a second support portion 22, and a connecting portion 24 are stored on the side of the lower surface 12 of the laminate 10. That is, when viewed from the stacking direction, the first support portion 21, the second support portion 22, and the connecting portion 24 overlap with the laminate 10 in the planar direction. The first support portion 21, the second support portion 22, and the connecting portion 24 are arranged side by side in the stacking direction (X-axis direction) in the order of first support portion 21, connecting portion 24, and second support portion 22. The connecting portion 24 is located between the first support portion 21 and the second support portion 22 and connects the first support portion 21 and the second support portion 22. The first support portion 21 has an upper surface 211 facing the lower surface 12 of the stacked body 10. A compression spring 13 extending in the stacking direction (X-axis direction) may be disposed between the first support portion 21 and the stacked body 10. The second support portion 22 has a lower surface 222 facing the lower surface 32 of the exterior member 30. The connecting portion 24 includes a spring 24a and a hydraulic chamber 24b.

[0017] Next, the surface pressure applying mechanism 20 will be described in detail. When the stack 10 expands and contracts, if one of the first support portion 21 and the second support portion 22 is in a movable state, the other support portion is in a fixed state. The movable state is a state in which the support portion can move in the stacking direction when a load is applied in the stacking direction. The fixed state is a state in which the support portion is fixed to the fixing portion 23 so as not to move even when a load is applied in the stacking direction. The fixing portion 23 is a member for fixing the positions of the first support portion 21 and the second support portion 22. The fixing portion 23 is a pair of plate-shaped members and is arranged so as to contact the inner side surface 33 and the inner side surface 34 of the exterior member 30, respectively. The fixing portions 23 are arranged so as to face each other along the side surface 33 and the inner side surface 34. The stack 10, the first support portion 21, the second support portion 22, and the connecting portion 24 are arranged between the left and right fixing portions 23, i.e., so as to be sandwiched between the pair of plate-shaped members. The first support portion 21 and the second support portion 22 are fixed to the fixing portions 23 at predetermined positions in the stacking direction, thereby becoming fixed. Furthermore, the first support portion 21 and the second support portion 22 are movable and can move between the left and right fixing portions 23 along the stacking direction.

[0018] The first support portion 21 and the second support portion 22 can change their positions in the stacking direction in the movable state and can receive the load applied from the laminated body 10 at any position by being fixed in their positions in the fixed state. In this embodiment, the first support portion 21 and the second support portion 22 change the positions at which they receive the load applied from the laminated body 10, thereby adjusting the surface pressure applied to the laminated body 10. For example, when the laminated body 10 is expanding, the positions of the first support portion 21 and / or the second support portion 22 move downward, preventing the surface pressure of the laminated body 10 from becoming excessive. Furthermore, when the laminated body 10 is contracting, the positions of the first support portion 21 and / or the second support portion 22 move upward, preventing the surface pressure of the laminated body 10 from becoming too small.

[0019] The first support portion 21 and the second support portion 22 can be switched between a movable state and a fixed state. Here, the operation of switching the states of the first support portion 21 and the second support portion 22 will be described using FIG. 2 . FIG. 2 is a partial front view showing an example of a surface pressure applying mechanism according to this embodiment. The X- and Y-axis indications in FIG. 2 correspond to the X- and Y-axis indications in FIG. 1 . FIG. 2 also shows a portion of the surface pressure applying mechanism 20 of the battery module 1 shown in FIG. 1 . In the example of FIG. 2 , the stack 10 is not shown, but a load P1 of the stack 10 is applied from above the first support portion 21 along the stacking direction (X-axis direction). Below, the configuration and operation of the support portions will be described using the first support portion 21 as an example. However, since the second support portion 22 has a configuration similar to the first support portion 21 and operates similarly to the first support portion 21, a description of the second support portion 22 will be omitted and the description of the first support portion 21 will be used as appropriate.

[0020] The first support portion 21 is a member including a substantially rectangular parallelepiped main body portion 21a, a locking mechanism portion 21b, a protrusion portion 21c, and a restriction portion 21d. The main body portion 21a has an upper surface 211 and a lower surface 212 located opposite the upper surface 211, and surfaces extending from each side of the upper surface 211 in a direction (X-axis direction) substantially perpendicular to the upper surface 211 are defined as side surfaces constituting the first support portion 21. Of the side surfaces constituting the first support portion 21, the side surface 213 and the side surface 214 are surfaces facing each other in the planar direction (Y-axis direction). The side surface 213 and the side surface 214 are arranged so as to face the left and right fixing portions 23, respectively. The side surface 213 and the side surface 214 are provided with through holes penetrating from the inside to the outside of the main body portion 21a.

[0021] The locking mechanism 21b, the protrusion 21c, and the restricting portion 21d are provided inside the main body 21a. The locking mechanism 21b is a mechanism for switching the first support portion 21 between a movable state and a fixed state. The locking mechanism 21b is disposed in the center of the main body 21a. The protrusions 21c are provided so as to connect to the left and right ends of the locking mechanism 21b in the planar direction (Y-axis direction). The protrusions 21c switch between a stored state in which they are stored in the main body 21a and a protruding state in which they protrude from the main body 21a. In the protruding state, the protrusions 21c disposed on the left and right protrude from the main body 21a through through holes in both side surfaces (side surface 213 and side surface 214) of the main body 21a. The first support portion 21 is fixed to the fixing portion 23 by fitting the protrusions 21c in the protruding state into recesses 23a provided in the fixing portion 23. That is, the movement of the first support portion 21 in the stacking direction is restricted by the protrusion 21c that fits into the recess 23a, and the position in the stacking direction is fixed at the position of the recess 23a. In this embodiment, a plurality of recesses 23a are arranged on the side of the fixing portion 23 so as to be aligned in the stacking direction. In the example of FIG. 2, four recesses 23a are arranged along the stacking direction on each of the left and right fixing portions 23. Each recess 23a is arranged so as to face the corresponding recess 23a on the opposite side. The position of the first support portion 21 in the stacking direction can be fixed at the position of each recess 23a in the stacking direction.

[0022] The locking mechanism 21b includes a spring 211b and a hydraulic chamber 212b that switch the state of the protrusion 21c. The spring 211b is a tension spring that connects the pair of protrusions 21c and is disposed within the hydraulic chamber 212b so as to extend in the Y-axis direction. The hydraulic chamber 212b is a hollow, tubular member, and both ends are sealed by the protrusions 21c. The hydraulic chamber 212b is a so-called cylinder. The protrusion 21c is disposed within the hydraulic chamber 212b so as to be slidable along the inner side surface. The protrusion 21c is a so-called piston. The hydraulic chamber 212b is filled with oil, and the hydraulic pressure can be adjusted by supplying and discharging the oil. By increasing the hydraulic pressure within the hydraulic chamber, the hydraulic chamber 212b pushes the protrusion 21c so that the protrusion 21c protrudes from the side surface of the main body 21a toward the fixed portion 23. This places the protrusion 21c in a protruding state. Furthermore, by reducing the hydraulic pressure inside the hydraulic chamber 212b, the spring 211b can bias the pair of protrusions 21c so that they approach each other. As a result, the protrusions 21c are pulled by the spring and stored inside the main body 21a, becoming the stored state. As described above, the locking mechanism 21b switches the state of the protrusions 21c between the stored state and the protruding state by adjusting the hydraulic pressure inside the hydraulic chamber 212b.

[0023] Furthermore, restricting portion 21d restricts movement of protrusion 21c so that tip 211d of protrusion 21c does not contact bottom 233a of recess 23a when protrusion 21c is engaged with recess 23a. Restricting portion 21d is installed at the connection between locking mechanism 21b and protrusion 21c. Restricting portion 21d restricts movement of protrusion 21c by coming into contact with side surfaces 213 and 214 of main body 21a, thereby restricting movement even when protrusion 21c is pressed toward fixing portion 23 by hydraulic pressure in a hydraulic chamber provided in locking mechanism 21b.

[0024] As described above, the first support portion 21 switches between a movable state and a fixed state by switching the state of the protruding portion 21c between the stored state and the protruding state. The first support portion 21 and the second support portion 22 support the stacked body 10 in the fixed state and apply surface pressure in accordance with the expansion and contraction of the stacked body 10. For example, when the first support portion 21 is in the fixed state, the first support portion 21 applies surface pressure to the stacked body 10. When the first support portion 21 is in the movable state, the load applied from the stacked body 10 is applied to the second support portion 22 via the first support portion 21.

[0025] The surface pressure applying mechanism 20 also includes a connecting portion 24 between the first support portion 21 and the second support portion 22. The connecting portion 24 includes a spring 24a and a hydraulic chamber 24b. The spring 24a is a tension spring located within the hydraulic chamber 24b and extending in the stacking direction, connecting the first support portion 21 and the second support portion 22. The spring 24a biases the first support portion 21 and the second support portion 22 toward each other, as indicated by arrow D2. The hydraulic chamber 24b is a hollow, tubular member, and both ends are sealed by the lower surface 212 of the first support portion 21 and the upper surface 221 of the second support portion 22, respectively. The hydraulic chamber 24b is surrounded by the lower surface 212 of the first support portion 21, the upper surface 221 of the second support portion 22, the side wall of the fixing portion 23, and the side wall of the exterior member 30. The hydraulic chamber 24b is a so-called cylinder. When in a movable state, the first support portion 21 and the second support portion 22 are arranged slidably along the inner side surface of the hydraulic chamber 24b. The first support portion 21 and the second support portion 22 are so-called pistons. The hydraulic chamber 24b is filled with oil, and the hydraulic pressure is adjusted by supplying and discharging the oil. For example, the hydraulic chamber 24b adjusts the internal hydraulic pressure by supplying and discharging oil through an opening provided in the recess 23a of the fixed portion 23. The hydraulic chamber 24b increases the internal hydraulic pressure by supplying oil, thereby biasing the first support portion 21 and the second support portion 22 away from each other, as indicated by arrow D3. When the hydraulic chamber 24b reduces the internal hydraulic pressure by discharging oil, the pressure that moves the first support portion 21 and the second support portion 22 away from each other weakens, and the tensile force by the spring 24a that moves the first support portion 21 and the second support portion 22 toward each other strengthens. In this embodiment, by adjusting the hydraulic pressure in the hydraulic chamber 24b, the first support portion 21 or the second support portion 22 in the movable state moves in the stacking direction due to hydraulic pressure or spring force. Specifically, when one of the first support portion 21 and the second support portion is in the movable state and the other support portion is in the fixed state, the greater the hydraulic pressure in the hydraulic chamber 24b, the more the hydraulic pressure in the hydraulic chamber 24b moves the one support portion in the movable state in the stacking direction away from the other support portion in the fixed state. Furthermore, the smaller the hydraulic pressure in the hydraulic chamber 24b, the more the spring 24a moves the one support portion in the movable state in the stacking direction toward the other support portion in the fixed state.

[0026] In this embodiment, the first support portion 21 may include an abutment portion 21e on the lower surface 212 of the first support portion 21. The lower surface 212 of the first support portion 21 faces the upper surface 221 of the second support portion 22. The lower surface 212 of the first support portion 21 and the upper surface 221 of the second support portion 22 are examples of the "main surface of the first support portion" and the "main surface of the second support portion" described in the claims. The lower surface 212 of the first support portion 21 has a first joint portion 212a that joins with one end of the spring 24a. The upper surface 221 of the second support portion 22 has a second joint portion 221a that joins with the other end of the spring 24a. The abutment portion 21e is located on a portion of the lower surface 212 of the first support portion 21 other than the first joint portion 212a. The lower surface 212 of the first support portion 21 and the upper surface 221 of the second support portion 22 are urged toward each other by the spring 24a as the hydraulic pressure in the hydraulic chamber 24b decreases. The abutting portion 21e is a portion where the lower surface 212 of the first support portion 21 and the upper surface 221 of the second support portion 22 abut against each other when the first support portion 21 and the second support portion 22 are brought closer by the spring 24a. The abutting portion 21e is formed to protrude from the lower surface 212 of the first support portion 21. In a state where the lower surface 212 of the first support portion 21 and the upper surface 221 of the second support portion 22 abut against each other at the abutting portion 21e, the first joint portion 212a and the second joint portion 221a are spaced apart by a predetermined length or more. The predetermined length is the minimum length of the spring 24a (the length at maximum compression). The contact portion 21e may be provided at a portion other than the second joint portion 221a on the upper surface 221 of the second support portion 22. The contact portion 21e may be provided at either one of the first support portion 21 and the second support portion 22, or at both.

[0027] In this embodiment, the adjustment of the hydraulic pressure in the hydraulic chambers of the first support portion 21, the second support portion 22, and the connecting portion 24 may be controlled by a controller (not shown). The controller is configured with a memory such as a ROM or a RAM, and a processor such as a CPU. The controller acquires the state of the stack body 10 and controls the hydraulic pressure in the hydraulic chambers of each portion according to the state of the stack body 10. The state of the stack body 10 includes, for example, the state of expansion and contraction or the state of the surface pressure of the stack body 10. The first support portion 21, the second support portion 22, and the connecting portion 24 adjust the hydraulic pressure according to commands from the controller. The controller may collectively control the first support portion 21, the second support portion 22, and the connecting portion 24, or may be provided for each of the first support portion 21, the second support portion 22, and the connecting portion 24.

[0028] In this embodiment, by switching between a movable state and a fixed state of the first support portion 21 and the second support portion, it is possible to prevent an excessive load from continuously acting on only one of the support portions, thereby increasing the durability of the surface pressure applying mechanism and appropriately maintaining the surface pressure of the laminate 10 for a long period of time. Furthermore, even when the thickness of the laminate 10 varies greatly in the stacking direction, it is possible to accommodate changes in the thickness of the laminate 10 by making the positions of the support portions variable. Therefore, there is no need to increase the size of the surface pressure applying mechanism so that it can accommodate the maximum variation in the thickness of the laminate 10, and the surface pressure applying mechanism can be made smaller.

[0029] Here, the movement of each support unit in a movable state will be described with reference to Figs. 3 and 4. Fig. 3 is a diagram illustrating an example of the movement of the first support unit in the surface pressure applying mechanism according to this embodiment. Fig. 4 is a diagram illustrating an example of the movement of the second support unit in the surface pressure applying mechanism according to this embodiment. Although the illustration of the stack 10 is omitted in Figs. 3 and 4 for the sake of explanation, a load P1 of the stack 10 is applied to the first support unit 21 from above. Fig. 3 shows a state in which the second support unit 22 supports the stack 10 in a fixed state. Fig. 4 shows a state in which the first support unit 21 supports the stack 10 in a fixed state.

[0030] First, the movement of the first support portion 21 in the movable state will be described with reference to FIG. 3. In FIG. 3, the state of the first support portion 21 transitions in the order of states (a), (b), (c), and (d). While the state of the first support portion 21 transitions from state (a) to state (d), the second support portion 22 receives a load P1 applied from the stacked body 10 while being fixed to the bottom recessed portion 23a. In state (a), the first support portion 21 is fixed to the top recessed portion 23a of the fixing portion 23. Both the first support portion 21 and the second support portion 22 support the stacked body 10. For example, in state (a), assume that the stacked body 10 expands and the surface pressure applied to the stacked body 10 becomes excessive. At this time, the position of the first support portion 21 in the stacking direction moves downward to adjust and reduce the surface pressure of the stacked body 10.

[0031] First, in state (b), the hydraulic pressure in the hydraulic chamber of the locking mechanism 21b is reduced to switch the state of the protrusion 21c to the housed state, and the first support portion 21 becomes movable. In states (a) and (b), the hydraulic pressure in the hydraulic chamber 24b is set to be high in order to support the position of the first support portion 21 so that the position of the first support portion 21 in the stacking direction is the same as the top recessed portion 23a. By reducing the hydraulic pressure in the hydraulic chamber 24b from state (b), the position of the first support portion 21, which was supported by the hydraulic chamber 24b, in the stacking direction moves downward D4.

[0032] In state (c), the first support portion 21 has moved downward to a position where the first support portion 21 and the second support portion 22 abut at the abutment portion 21e. In state (c), the first support portion 21 is located below the position of the second recessed portion 23a from the top of the fixed portion 23. From state (c), by increasing the hydraulic pressure in the hydraulic chamber 24b, the first support portion 21 is urged upward, and the position of the first support portion 21 in the stacking direction moves to the same position as the second recessed portion 23a from the top of the fixed portion 23. In state (d), the hydraulic pressure in the hydraulic chamber of the locking mechanism portion 21b is increased at the position of the second recessed portion 23a from the top of the fixed portion 23, and the state of the protruding portion 21c of the first support portion 21 is switched to the protruding state. The protruding portion 21c in the protruding state engages with the recessed portion 23a, and the first support portion 21 is fixed. As described above, the first support portion 21 moves in the stacking direction.

[0033] Next, the movement of the second support portion 22 in the movable state will be described with reference to FIG. 4. In FIG. 4, the state of the second support portion 22 transitions in the order of (a), (b), (c), and (d). While the state of the second support portion 22 transitions from (a) to (d), the first support portion 21 receives a load P1 applied from the stacked body 10 while being fixed to the second recessed portion 23a from the top of the fixed portion 23. The state (a) in FIG. 4 is the same state as the state (d) in FIG. 3. In the state (a) in FIG. 4, the first support portion 21 is fixed to the second recessed portion 23a from the top of the fixed portion 23, and the second support portion 22 is fixed to the fourth recessed portion 23a from the top of the fixed portion 23. In other words, both the first support portion 21 and the second support portion 22 support the stacked body 10 in a fixed state. FIG. 4 illustrates an example in which the position of the first support portion 21 in the stacking direction is moved downward in the example of FIG. 3, and then the position of the second support portion 22 is moved downward in the stacking direction.

[0034] In state (b), the second support portion 22 is movable by reducing the hydraulic pressure in the hydraulic chamber of the locking mechanism portion 21b, switching the state of the protrusion 21c to the retracted state. At this time, by reducing the hydraulic pressure in the hydraulic chamber 24b, the second support portion 22 is pulled by the spring 24a and moves upward to a position where the first support portion 21 and the second support portion 22 abut at the abutment portion 21e. By increasing the hydraulic pressure in the hydraulic chamber 24b from state (b), the position of the second support portion 22 in the stacking direction moves downward D4 due to the hydraulic pressure. In state (c), the second support portion 22 is lower than the position of the fifth recessed portion 23a from the top of the fixed portion 23. By reducing the hydraulic pressure in the hydraulic chamber 24b from state (c), the second support portion 22 is pulled by the spring 24a and moves in the stacking direction to the same position as the fifth recessed portion 23a from the top of the fixed portion 23. In the state (d), the second support portion 22 switches the state of the protruding portion 21c to the protruding state by increasing the hydraulic pressure in the hydraulic chamber of the locking mechanism portion 21b at the position of the fifth recessed portion 23a from the top of the fixed portion 23. The second support portion 22 is fixed by the protruding portion 21c engaging with the recessed portion 23a. As described above, the second support portion 22 moves in position in the stacking direction.

[0035] In this embodiment, the positions of the first support portion 21 and the second support portion 22 in the stacking direction can be changed by alternately performing a moving operation in which one support portion is fixed and the other support portion is moved in a movable state in the stacking direction on the first support portion 21 and the second support portion 22. As shown in FIGS. 3 and 4, the surface pressure applying mechanism 20 can switch from a state in which the first support portion 21 is fixed and supports the stacked body 10 (FIG. 4) to a state in which the second support portion 22 is fixed and supports the stacked body 10 (FIG. 3). Conversely, the surface pressure applying mechanism 20 can switch from a state in which the second support portion 22 is fixed and supports the stacked body 10 (FIG. 3) to a state in which the first support portion 21 is fixed and supports the stacked body 10 (FIG. 4). In each switching process, the movable support portion can move its position in the stacking direction, so the distance between the first support portion 21 and the second support portion 22 changes. For example, in the example of Fig. 3, the distance between the first support portion 21 and the second support portion 22 in state (c) is smaller than the distance between the first support portion 21 and the second support portion 22 in state (b). Also, in the example of Fig. 4, the distance between the first support portion 21 and the second support portion 22 in state (c) is larger than the distance between the first support portion 21 and the second support portion 22 in state (b).

[0036] Furthermore, the stroke amount (movement amount) by which one of the movable support parts moves in the stacking direction in one switching step is smaller than the maximum stroke amount by which one of the movable support parts can move in the stacking direction. In this embodiment, when the series of movement operations shown in FIGS. 3 and 4 are considered to be one switching step, the movable support part moves between adjacent recesses 23a among the multiple recesses 23a in one switching step. That is, the stroke amount of the support part in one switching step is the distance between adjacent recesses 23a. Furthermore, for example, when three or more recesses 23a are provided as shown in FIGS. 3 and 4, one switching step can be repeated multiple times, and therefore the maximum stroke amount of the support part is greater than the stroke amount of the support part in one switching step.

[0037] Furthermore, the direction in which the first support portion 21 moves when the second support portion 22 is fixed and supporting the stacked body 10 is the same as the direction in which the second support portion 22 moves when the first support portion 21 is fixed and supporting the stacked body 10. For example, as shown in FIGS. 3 and 4, when the first support portion 21 moves downward, the second support portion 22 also moves downward following it. Furthermore, although an example in which the first support portion 21 and the second support portion 22 move downward has been described in FIGS. 3 and 4, the first support portion 21 and the second support portion 22 may move upward. Even in this case, the first support portion 21 and the second support portion 22 move in the same direction.

[0038] 3 and 4 , one switching cycle includes the steps of: moving the position of the second support 22 relative to the first support 21 in the stacking direction while the first support 21 is supporting the stacked body 10 in a fixed state; switching from a state in which the first support 21 is supporting the stacked body 10 in a fixed state to a state in which the second support 22 is supporting the stacked body 10 in a fixed state; moving the position of the first support 21 relative to the second support 22 in the stacking direction while the second support 22 is supporting the stacked body 10 in a fixed state; and switching from a state in which the second support 22 is supporting the stacked body 10 in a fixed state to a state in which the first support 21 is supporting the stacked body 10 in a fixed state.

[0039] For example, in the example of FIG. 3 , the process of transitioning from state (b) to state (c) in FIG. 3 is a process of moving the position of the first support member 21 relative to the second support member 22 in the stacking direction while the second support member 22 supports the stacked body 10 in a fixed state. Furthermore, the process of transitioning from state (c) in FIG. 3 to state (b) in FIG. 4 is a process of switching from a state in which the second support member 22 supports the stacked body 10 in a fixed state to a state in which the first support member 21 supports the stacked body 10 in a fixed state. In the example of FIG. 4 , the process of transitioning from state (b) to state (c) in FIG. 4 is a process of moving the position of the second support member 22 relative to the first support member 21 in the stacking direction while the first support member 21 supports the stacked body 10 in a fixed state. Furthermore, the process of transitioning from state (c) in FIG. 4 to state (b) in FIG. 3 is a process of switching from a state in which the first support member 21 supports the stacked body 10 in a fixed state to a state in which the second support member 22 supports the stacked body 10 in a fixed state.

[0040] Furthermore, the switching step of switching between a state in which the first support portion 21 supports the stack body 10 in a fixed state and a state in which the second support portion 22 supports the stack body 10 in a fixed state includes a step of supporting the stack body 10 with both the first support portion 21 and the second support portion 22 in a fixed state. For example, in Figures 3 and 4, states (a) and (d) in Figure 3 and states (a) and (d) in Figure 4 correspond to the step of supporting the stack body 10 with both the first support portion 21 and the second support portion 22 in a fixed state.

[0041] As described above, the surface pressure applying mechanism according to this embodiment applies a compressive load to a stack of an all-solid-state battery to apply a surface pressure, and includes first and second support members positioned relative to the stack in the stack direction to support the stack, a fixing member for fixing the positions of the first and second support members, and a spring and hydraulic chamber positioned between the first and second support members to connect the first and second support members. When the stack expands or contracts, when one of the first and second support members is in a movable state, the other support member is in a fixed state. The movable state is a state in which the first and second support members can move in the stack direction when subjected to a load from the stack direction, and the fixed state is a state in which the first and second support members are fixed to the fixing member so as not to move even when subjected to a load from the stack direction. The first and second support members can be switched between the movable state and the fixed state. This allows the surface pressure applying mechanism to be miniaturized.

[0042] Furthermore, in the surface pressure applying mechanism according to this embodiment, the distance between the first support part and the second support part changes in a switching process of switching from a state in which the first support part supports the stack in a fixed state to a state in which the second support part supports the stack in a fixed state, and in a switching process of switching from a state in which the second support part supports the stack in a fixed state to a state in which the first support part supports the stack in a fixed state. As a result, while one support part is supporting the stack, the position of the other support part can be moved, thereby changing the position at which the other support part is fixed.

[0043] Furthermore, in the surface pressure applying mechanism according to this embodiment, the stroke amount of one of the movable support parts in the stacking direction during the switching process between a state in which the first support part is fixed and supporting the stack body and a state in which the second support part is fixed and supporting the stack body is switched is smaller than the maximum stroke amount that the movable support part can move in the stacking direction. This reduces the stroke amount during one switching process, allowing the size of the surface pressure applying mechanism to be reduced, and the number of stacked layers in the stack body to be increased, thereby increasing battery capacity.

[0044] Furthermore, in the surface pressure applying mechanism according to this embodiment, the direction in which the first support part moves when the second support part is fixed and supporting the stack is the same as the direction in which the second support part moves when the first support part is fixed and supporting the stack, which allows a predetermined distance to be maintained between the support parts, and therefore allows the movement of each support part to be repeated.

[0045] Furthermore, in the surface pressure applying mechanism according to this embodiment, the first support member and the second support member repeatedly execute a switching cycle, which includes the steps of: moving the second support member in the stacking direction relative to the first support member while the first support member is supporting the stack in a fixed state; switching from a state in which the first support member supports the stack in a fixed state to a state in which the second support member supports the stack in a fixed state; moving the first support member in the stacking direction relative to the second support member while the second support member is supporting the stack in a fixed state; and switching from a state in which the second support member supports the stack in a fixed state to a state in which the first support member supports the stack in a fixed state. This configuration, which repeatedly executes the switching cycle, allows the maximum stroke amount to be increased beyond the stroke amount in a single switching step. By reducing the stroke amount in a single switching step, the size of the surface pressure applying mechanism can be reduced, allowing the number of stacked layers to be increased, thereby increasing battery capacity.

[0046] Furthermore, in the surface pressure applying mechanism according to this embodiment, the load applied from the laminated body is applied to the second support portion via the first support portion, which allows a large stroke to be achieved by repeating small strokes.

[0047] Furthermore, in the surface pressure applying mechanism according to this embodiment, the first support portion and the second support portion are provided with a locking mechanism portion for switching between a movable state and a fixed state, thereby making it possible to switch between the movable state and the fixed state of the support portions.

[0048] Furthermore, in the surface pressure applying mechanism according to this embodiment, the first support part and the second support part each include a main body part and a protruding part that switches between a stored state in which it is stored in the main body part and a protruding state in which it protrudes from the main body part, and the protruding part is fixed to the fixed part by fitting into a recess provided in the fixed part in the protruding state, and the locking mechanism part includes a spring and a hydraulic chamber that switch the state of the protruding part, thereby making it possible to switch the state of the protruding part on the support part.

[0049] Furthermore, in the surface pressure applying mechanism according to this embodiment, the first support part and the second support part include a restricting part that restricts movement of the protrusion so that the tip of the protrusion does not contact the bottom of the recess when the protrusion is engaged with the recess, thereby preventing excessive surface pressure from being applied to the locking mechanism.

[0050] Furthermore, in the surface pressure applying mechanism according to this embodiment, when one of the first support part and the second support part is in a movable state and the other support part is in a fixed state, the greater the hydraulic pressure in the hydraulic chamber, the more the hydraulic pressure causes the one support part in the movable state to move in the stacking direction away from the other support part in the fixed state, and the smaller the hydraulic pressure, the more the spring causes the one support part in the movable state to move in the stacking direction toward the other support part in the fixed state. This allows the positions of the support parts in the stacking direction to be adjusted.

[0051] Furthermore, in the surface pressure applying mechanism according to this embodiment, the main surfaces of the first support portion and the second support portion are arranged to face each other, the main surface of the first support portion has a first joint portion that joins with one end of the spring, the main surface of the second support portion has a second joint portion that joins with the other end of the spring, the main surfaces of the first support portion and / or the second support portion have abutment portions that abut against each other when the first support portion and the second support portion are brought closer by the spring, the abutment portions are located on a portion of the main surface of the first support portion other than the first joint portion and / or a portion of the main surface of the second support portion other than the second joint portion, and are formed to protrude from the main surface of the first support portion and / or the main surface of the second support portion so that the first joint portion and the second joint portion are spaced apart by a predetermined distance or more when the main surfaces of the first support portion and the second support portion abut at the abutment portions, thereby preventing damage to the spring.

[0052] Furthermore, in the surface pressure applying mechanism according to this embodiment, the switching step of switching between a state in which the first support unit supports the stack in a fixed state and a state in which the second support unit supports the stack in a fixed state includes a step of supporting the stack with both the first support unit and the second support unit in a fixed state, thereby preventing the surface pressure on the stack from being lost.

[0053] It should be noted that the above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above-described embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Explanation of symbols]

[0054] 1...Battery module 10...Laminate 20...Surface pressure applying mechanism 21...First support part 22…Second support part 23…Fixed part 24...Connection part 24a...Spring 24b...Hydraulic chamber 30...Exterior material

Claims

1. A surface pressure applying mechanism that applies a compressive load in a stacking direction to a stack of all-solid-state batteries to apply surface pressure, a first support portion and a second support portion positioned in the stacking direction relative to the stack to support the stack; a fixing portion for fixing the positions of the first support portion and the second support portion; a spring and hydraulic chamber located between the first support portion and the second support portion and connecting the first support portion and the second support portion, When the stacked body expands and contracts, when one of the first support portion and the second support portion is in a movable state, the other support portion is in a fixed state; The movable state is a state in which the stacking member is movable in the stacking direction when a load is applied from the stacking direction, The fixed state is a state in which the sheet is fixed to the fixing portion so as not to move even when a load is applied from the stacking direction, The first support portion and the second support portion are a surface pressure applying mechanism that can be switched between the movable state and the fixed state.

2. The surface pressure applying mechanism according to claim 1, a surface pressure applying mechanism in which a distance between the first support portion and the second support portion changes during a switching process of switching from a state in which the first support portion supports the stack in the fixed state to a state in which the second support portion supports the stack in the fixed state, and during a switching process of switching from a state in which the second support portion supports the stack in the fixed state to a state in which the first support portion supports the stack in the fixed state.

3. 3. The surface pressure applying mechanism according to claim 1 or 2, a surface pressure applying mechanism in which, in a switching process for switching between a state in which the first support portion supports the stack in the fixed state and a state in which the second support portion supports the stack in the fixed state, the stroke amount by which the one support portion in the movable state moves in the stacking direction is smaller than the maximum stroke amount by which the one support portion in the movable state can move in the stacking direction.

4. 3. The surface pressure applying mechanism according to claim 1 or 2, A surface pressure applying mechanism in which a moving direction of the first support part when the second support part is supporting the stack in the fixed state is the same as a moving direction of the second support part when the first support part is supporting the stack in the fixed state.

5. 3. The surface pressure applying mechanism according to claim 1 or 2, The first support portion and the second support portion repeatedly perform a switching cycle, The switching cycle comprises: a step of moving a position of the second support portion relative to the first support portion in the stacking direction while the first support portion supports the stack in the fixed state; a step of switching from a state in which the first support portion supports the stack in the fixed state to a state in which the second support portion supports the stack in the fixed state; a step of moving a position of the first support portion relative to the second support portion in the stacking direction while the second support portion supports the stack in the fixed state; and switching from a state in which the second support portion supports the stack in the fixed state to a state in which the first support portion supports the stack in the fixed state.

6. 3. The surface pressure applying mechanism according to claim 1 or 2, a surface pressure applying mechanism that applies a load applied from the stack to the second support portion via the first support portion;

7. 3. The surface pressure applying mechanism according to claim 1 or 2, The surface pressure applying mechanism includes a locking mechanism for switching the first support portion and the second support portion between the movable state and the fixed state.

8. The surface pressure applying mechanism according to claim 7, The first support portion and the second support portion are a main body; a protrusion that switches between a stored state in which it is stored in the main body and a protruding state in which it protrudes from the main body, The protruding portion is fixed to the fixing portion by fitting into a recess provided in the fixing portion in the protruding state, The locking mechanism is a surface pressure applying mechanism including a spring and a hydraulic chamber that switches the state of the protrusion.

9. The surface pressure applying mechanism according to claim 8, The first support portion and the second support portion are a surface pressure applying mechanism including a restricting portion that restricts movement of the protrusion so that the tip of the protrusion does not come into contact with the bottom of the recess when the protrusion is engaged with the recess;

10. 3. The surface pressure applying mechanism according to claim 1 or 2, The first support portion and the second support portion are A surface pressure applying mechanism in which, when one of the support parts is in the movable state and the other support part is in the fixed state, the greater the oil pressure in the hydraulic chamber, the more the oil pressure causes the one support part in the movable state to move in the stacking direction away from the other support part in the fixed state, and the smaller the oil pressure, the more the spring causes the one support part in the movable state to move in the stacking direction toward the other support part in the fixed state.

11. The surface pressure applying mechanism according to claim 10, a main surface of the first support portion and a main surface of the second support portion are arranged to face each other, a main surface of the first support portion has a first joining portion that joins with one end of the spring; a main surface of the second support portion has a second joining portion that joins with the other end of the spring; a main surface of the first support portion and / or a main surface of the second support portion have an abutment portion that abuts against each other when the first support portion and the second support portion are brought closer by the spring, The abutment portion is located in a portion of the main surface of the first support portion other than the first joint portion and / or in a portion of the main surface of the second support portion other than the second joint portion, a surface pressure applying mechanism formed to protrude from the main surface of the first support portion and / or the main surface of the second support portion so that the first joint portion and the second joint portion are spaced apart by a predetermined length or more when the main surface of the first support portion and the main surface of the second support portion are in contact at the contact portion.

12. 3. The surface pressure applying mechanism according to claim 1 or 2, A surface pressure applying mechanism in which a switching process for switching between a state in which the first support portion supports the stack in the fixed state and a state in which the second support portion supports the stack in the fixed state includes a process in which both the first support portion and the second support portion support the stack in the fixed state.

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