Battery module

Abstract

The present invention provides a battery module that avoids interference between the wiring and the housing, etc., and facilitates miniaturization, in a battery module equipped with wiring for measuring the voltage of each of the multiple stacked battery cells. [Solution] The device includes a plurality of stacked battery cells 3, a plurality of connecting terminals 4 connected one-to-one to tabs extending from the battery cells 3 or to busbars 33 connecting the tabs, a plurality of insulating connection parts 7 arranged in the same number as the connecting terminals 4 in a direction perpendicular to the stacking direction, a plurality of plug pins 8 supporting the plurality of connection parts 7 and electrically connected to a voltage measuring means (not shown), and a plurality of flexible wirings 5 ​​for voltage measurement that connect the connecting terminals 4 and the connection parts 7 one-to-one, wherein the plurality of plug pins 8 and the plurality of wirings 5 ​​are electrically connected to each other one-to-one, and the wirings 5 ​​are connected to the connecting terminals 4 in a state where they extend from the connection parts 7 in a direction along the stacking direction.

Description

[Technical Field]

[0001] This invention relates to a battery module. [Background technology]

[0002] Patent Document 1 discloses a battery module that includes a plurality of stacked battery cells, a plurality of busbars connecting two battery cells adjacent to each other in the stacking direction of the battery cells, a battery wiring module having the same number of voltage measuring wires as the busbars and arranged adjacent to the busbars and extending in the stacking direction, and a plurality of connecting conductors that individually connect the busbars and the wires. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2015 / 099062 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in Patent Document 1, the busbar is fixed to the housing that contains the battery cells. Therefore, when applied to battery cells such as all-solid-state batteries that expand in the thickness direction when charged and contract in the thickness direction when discharged, stress is applied between the tabs extending from the battery cells and the busbar during charging and discharging, which may cause damage. To resolve this, a configuration in which the busbar is not fixed to the housing and voltage measurement wiring is placed on the busbar or tabs can be considered. In this case, it is necessary to leave enough slack in the wiring to follow the expansion and contraction of the stacked battery cells, but if the slack is too large, it will interfere with the housing (or equipment outside the battery module).

[0005] The present invention aims to provide a battery module that avoids interference between the wiring and the housing, etc., and facilitates miniaturization, in a battery module to which wiring for measuring the voltage of multiple stacked battery cells is attached. [Means for solving the problem]

[0006] The battery module according to the present invention includes a plurality of stacked battery cells, a plurality of connecting terminals connected one-to-one to tabs extending from the battery cells or to busbars connecting two adjacent tabs in the stacking direction of the battery cells, a plurality of insulating connection parts arranged in the same number as the connecting terminals in a direction perpendicular to the stacking direction, a plurality of plug pins supporting the plurality of connection parts in a manner that simultaneously penetrates the plurality of connection parts while being insulated from each other, and electrically connected to an external voltage measuring means, and a plurality of flexible wirings for voltage measurement that connect the connecting terminals and connection parts one-to-one. One of the plurality of plug pins is electrically connected to a wiring connected to one of the plurality of connection parts, and is insulated from the wiring connected to the other connection parts of the plurality of plug pins, so that the plurality of plug pins and the plurality of wirings are electrically connected to each other one-to-one, and the wiring is connected to the connecting terminals while extending from the connection parts in a direction along the stacking direction. [Effects of the Invention]

[0007] According to the present invention, when the thickness of a stacked battery cell formed by stacking multiple battery cells changes in the stacking direction due to charging and discharging, the position of the tabs or busbars changes in the thickness direction. However, since the wiring is connected to the connecting terminals while extended in the stacking direction, the connecting terminals maintain their extended state in the stacking direction while absorbing the change in the position of the tabs or busbars. Therefore, the wiring for measuring the voltage of each battery cell constituting the stacked battery cell can be compactly housed, increasing the volume density of the battery module and reducing interference with the housing or external equipment that houses the stacked battery cell. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a side view of the battery module of the first embodiment when the charge level of the stacked battery cells is approximately zero. [Figure 2] Figure 2 is a plan view of the battery module of the first embodiment when the charge level of the stacked battery cells is approximately zero. [Figure 3] Figure 3 is a side view of the battery module of the first embodiment when the charge level of the stacked battery cells is at the charge level corresponding to full charge. [Figure 4] Figure 4 is a plan view of the battery module of the first embodiment when the charge level of the stacked battery cells is at the charge level corresponding to full charge. [Figure 5] Figure 5 shows the coupling terminal and busbar, where Figure 5(a) shows the coupling terminal before it is attached to the busbar, and Figure 5(b) shows the coupling terminal after it has been attached to the busbar. [Figure 6] Figure 6 is a plan view of the connection section (wiring, without plug pins). [Figure 7] Figure 7 is a cross-sectional view of the first support section, the second support section, the connecting section, and the plug pin. [Figure 8] Figure 8 is an exploded perspective view of the first support section, the connecting section, and the plug pin. [Figure 9] Figure 9 is a cross-sectional view of the wiring. [Figure 10] Figure 10 is a plan view (part 1) showing the arrangement of connection points and wiring. [Figure 11] Figure 11 is a plan view (part 2) showing the arrangement of the connection points and wiring. [Figure 12] Figure 12 is a plan view (part 3) showing the arrangement of the connection points and wiring. [Figure 13] Figure 13 is a plan view showing the arrangement of connecting terminals, connection parts, and wiring. Figure 13(a) shows the arrangement of connecting terminals, connection parts, and wiring when the charge level of the stacked battery cell is approximately zero, and Figure 13(b) shows the arrangement of connecting terminals, connection parts, and wiring when the charge level of the stacked battery cell is at a charge level corresponding to full charge. [Figure 14] Figure 14 shows the relationship between the center position (Pn) of the stacked battery cells in a battery module, specifically the center position (Pn0) when the charge level of the stacked battery cells is approximately zero, the center position (PnF) when the charge level of the stacked battery cells is close to full charge, and the number of stacked battery cells (n). [Figure 15]FIG. 15 is a perspective view of a battery module of a comparative example, FIG. 14(a) is a perspective view when the charge rate of the stacked battery cells is the charge rate corresponding to full charge, and FIG. 14(b) is a perspective view when the charge rate of the stacked battery cells is substantially zero. [Figure 16] FIG. 16 is a view showing a case where a folded structure is provided in the wiring shown in FIG. 15. [Figure 17] FIG. 17 is a cross-sectional view of the wiring of a modification of the first embodiment. [Figure 18] FIG. 18 is a plan view showing the arrangement relationship between the connection terminal, the connection portion, and the wiring of the modification. FIG. 18(a) shows the arrangement relationship between the connection terminal, the connection portion, and the wiring of the modification when the charge rate of the stacked battery cells is substantially zero, and FIG. 18(b) shows the arrangement relationship between the connection terminal, the connection portion, and the wiring of the modification when the charge rate of the stacked battery cells is the charge rate corresponding to full charge. [Figure 19] FIG. 19 is a side view of the battery module of the second embodiment. [Figure 20] FIG. 20 is a plan view of the battery module of the second embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0010] FIG. 1 is a side view of the battery module 1 of the first embodiment when the charge rate of the stacked battery cells is substantially zero. FIG. 2 is a plan view of the battery module 1 of the first embodiment when the charge rate of the stacked battery cells is substantially zero. FIG. 3 is a side view of the battery module 1 of the first embodiment when the charge rate of the stacked battery cells is the charge rate corresponding to full charge. FIG. 4 is a plan view of the battery module 1 of the first embodiment when the charge rate of the stacked battery cells is the charge rate corresponding to full charge. In the figures, the X-axis, Y-axis, and Z-axis are assumed to be orthogonal to each other.

[0011] The battery module 1 of the first embodiment is mainly attached to an electric vehicle or a hybrid vehicle.

[0012] As shown in Figure 1 and other figures, the battery module 1 of the first embodiment has a configuration in which battery cells 3 are stacked in the thickness direction (X direction) of the battery cells 3 to form a stacked battery cell, the stacked battery cell is sandwiched between a fixed end plate 21 and a movable end plate 22, and the movable end plate 22 is pressed toward the fixed end plate 21 by a pressurizing mechanism 23.

[0013] The pressurizing mechanism 23 includes multiple pressurizing parts (rod 231, actuator 232) and a fixing part 233.

[0014] The rod 231 has its longitudinal direction oriented in the stacking direction (X direction) of the stacked battery cells, and its end is in contact with the movable end plate 22.

[0015] The actuator 232 presses the rod 231 toward the movable end plate 22 with a predetermined pressing force. Therefore, as described later, when the battery cell 3 contracts in the thickness direction (X direction), the rod 231 (movable end plate 22) moves in the -X direction and stops at a position where the pressing force of the actuator 232 and the repulsive force of the stacked battery cell (battery cell 3) are in equilibrium. Also, as described later, when the stacked battery cell (battery cell 3) expands in the thickness direction, the rod 231 (movable end plate 22) moves in the +X direction and stops at a position where the pressing force of the actuator 232 and the repulsive force of the stacked battery cell (battery cell 3) are in equilibrium.

[0016] The fixed part 233 is fixed to the vehicle and supports the actuator 232 (rod 231).

[0017] The fixed end plate 21 is fixed to the vehicle or is integrated with the fixing part 233. Although not shown in the illustration, a plurality of cylindrical members (not shown) extending in the +X direction are arranged from the periphery of the fixed end plate 21, and these cylindrical members (not shown) are inserted into through holes (not shown) formed in the periphery of the movable end plate 22.

[0018] The movable end plate 22 is slidable along the longitudinal direction (X direction) of the rod (not shown). The movable end plate 22 slides the cylindrical member (not shown) when pressed by the rod 231, and presses against the stacked battery cell (battery cell 3).

[0019] The battery cell 3 is, for example, an all-solid-state battery (or a lithium-ion battery with a liquid electrolyte layer), and is a structure in which a positive electrode current collector foil (not shown), a positive electrode layer (not shown), a solid electrolyte layer (not shown), a negative electrode layer (not shown), and a negative electrode current collector foil (not shown) are stacked in that order and housed in a package. When the battery cell 3 is charged, lithium ions move from the positive electrode layer to the negative electrode layer (not shown), causing the negative electrode layer to expand and the battery cell 3 to expand in the thickness direction. Conversely, when it is discharged, lithium ions accumulated in the negative electrode layer move to the positive electrode layer, causing the battery cell 3 to contract in the thickness direction.

[0020] The battery cell 3 has a positive electrode tab 31 connected to the positive electrode current collector foil and extending to the outside of the package, and a negative electrode tab 32 connected to the negative electrode current collector foil and extending to the outside of the package.

[0021] The positive electrode tab 31 and the negative electrode tab 32 extend from the side of the battery cell 3 (the side facing the Y direction).

[0022] Multiple battery cells 3 are stacked in the X direction with their thickness direction oriented in the X direction to form a stacked battery cell. As shown in Figures 2 and 4, the positive electrode tabs 31 and negative electrode tabs 32 are arranged alternately in the X direction so that they are staggered in a plan view. Here, the battery cells 3 are numbered 3A-3N in order from closest to the fixed end plate 21.

[0023] The positive electrode tab 31 of one of two battery cells 3 adjacent to each other in the X direction and the negative electrode tab 32 of the other battery cell 3 are connected by a busbar 33, and all battery cells 3 are electrically connected in series.

[0024] As shown in Figures 2 and 4, for example, seven busbars 33 are attached to the left side (+Y direction) of the battery cell 3, and six busbars 33 are attached to the right side (-Y direction) of the battery cell 3, but this changes depending on the number of stacked battery cells 3.

[0025] As shown in Figures 1 and 3, the positive electrode tab 31, the negative electrode tab 32, and the busbar 33 are positioned such that, for example, their length in the Z direction is less than or equal to half the height (Z direction) dimension of the battery cell 3, and they are positioned off-center in the -Z direction on the Y-axis side of the battery cell 3.

[0026] Note that busbars 33 are not attached to the positive terminal tab 31, which is the positive end in the series connection, and the negative terminal tab 32, which is the negative end. The positive terminal tab 31 is connected to the positive terminal on the series side of an inverter (not shown) that controls, for example, a drive motor (not shown) that drives an electric vehicle. Similarly, the negative terminal tab 32 is connected to the negative terminal on the series side of the inverter (not shown).

[0027] Conductive connecting terminals 4 (4LA-4LG) are attached in a one-to-one relationship to the busbar 33 and to the positive and negative terminal tabs 31 and 32, which are the ends of the series connection.

[0028] As shown in Figures 2 and 4, the connecting terminals 4LA-4LG are attached to the left side of the battery cell 3 in order of proximity to the fixed end plate 21, and the connecting terminals 4RA-4RH are attached to the right side of the battery cell 3 in order of proximity to the fixed end plate 21.

[0029] Figure 5 shows the connecting terminal 4 and the busbar 33, where Figure 5(a) shows the state before the connecting terminal 4 is attached to the busbar 33, and Figure 5(b) shows the state after the connecting terminal 4 is attached to the busbar 33.

[0030] As shown in Figure 5(a), the connecting terminal 4 includes a clamping portion 41 and a terminal portion 42. The clamping portion 41 has two arms. As shown in Figure 5(b), the clamping portion 41 is structured to clamp the busbar 33 (or positive electrode tab 31, negative electrode tab 32) from its thickness direction. After the clamping portion 41 is clamped onto the busbar 33, it is fixed to the busbar 33 by welding or the like.

[0031] As shown in Figures 5(a) and 5(b), the terminal portion 42 extends from the base of the arm of the clamping portion 41 in the opposite direction to the arm, and the wiring 5 (Figures 1 to 4), which will be described later, is attached to its tip.

[0032] As shown in Figures 1 and 3, the terminal portion 42 of the connecting terminals 4RA-4RH is configured such that the length in the Z direction becomes shorter the closer it is to the movable end plate 22.

[0033] Flexible wires 5 (5RA-5RH) are connected one-to-one to the ends of each connecting terminal 4RA-4RH (terminal section 42). Each wire 5 (5RA-5RH) is then connected one-to-one to a connecting section 7 (7RA-7RH).

[0034] A plug pin 8 (8RA-8RH) (Figure 7) extends in the Z direction and passes through the connection portion 7 (7RA-7RH). The plug pin 8 (8RA-8RH) is supported at the -Z end by the first support portion 61R and at the +Z end by the second support portion 62R.

[0035] Although not shown in the diagram, similar to the connecting terminals 4RA-4RH, the terminal portion 42 of the connecting terminal 4LA-4LF is configured such that its length in the Z direction becomes shorter the closer it is to the movable end plate 22.

[0036] Each end of the connecting terminal 4LA-4LG (terminal section 42) is connected in a one-to-one relationship to a flexible wire 5 (5LA-5LG). Each wire 5LA-5LG is then connected in a one-to-one relationship to a connecting section 7 (7LA-7LG).

[0037] A cylindrical plug pin 8 (8LA-8LG) extending in the Z direction passes through the connection portion 7 (7LA-7LG). The plug pin 8 (8LA-8LG) is supported at the -Z end by an insulating first support portion 61R and at the +Z end by an insulating second support portion 62R.

[0038] Figure 6 is a plan view of the connection part 7 (without wiring 5 and plug pin 8). Figure 7 is a cross-sectional view of the first support part 61R, the second support part 62R, the connection part 7 (7RA-7RH), and the plug pin 8. Figure 7 is an exploded perspective view of the first support part 61R, the connection part 7 (7RA-7RH), and the plug pin 8 (8RA-8RH).

[0039] The connector 7 is made of an insulating material and has a bobbin shape. The connector 7 includes a cylindrical (pancake-shaped) body 71 around which the wiring 5 is wound, a flange portion 72 (not shown in Figure 6) located at the -Z end of the body 71, and a flange portion 73 located at the +Z end of the body 71.

[0040] The main body 71 has through holes 711 through which the plug pins 8 are inserted. The through holes 711 (711A-711H) are arranged at equal intervals in the circumferential direction, with the same number of holes as the number of plug pins 8 (8RA-8RH) (the same number as the number of wires 5 (5RA-5RH)), so as to circle around the center of the main body 71.

[0041] The first support portion 61R and the second support portion 62R (omitted in Figure 8) have the same number of mounting holes 611 and 621 as there are plug pins 8 (8RA-8RH), respectively, and the plug pins 8 (8RA-8RH), which are inserted through the through holes 711 of the connecting portion 7, are fitted into the mounting holes 611 and 621. As a result, the plug pins 8 (8RA-8RH) are supported by the first support portion 61R and the second support portion 62R, and the connecting portion 7 (7RA-7RH) is supported by the plug pins 8 (8RA-8RH).

[0042] Plug pins 8RA-8RH are formed from a conductive material (e.g., Cu (copper)). Plug pins 8RA-8RH are connected to external wiring 9RA-9RH (Figures 1 and 3), respectively.

[0043] Although not shown in the diagram, plug pins 8RA-8RH are connected to external wiring 9LA-9LF, respectively.

[0044] External wiring 9RA-9RH and external wiring 9LA-9LG are connected to a voltage measuring means (not shown) for measuring the voltage of battery cell 3 (3A-3N).

[0045] Figure 9 is a cross-sectional view of wiring 5. Figure 10 is a plan view (1) showing the arrangement of connection part 7RA and wiring 5RA. Figure 11 is a plan view (2) showing the arrangement of connection part 7RB and wiring 5RB. Figure 12 is a plan view (3) showing the arrangement of connection part 7RH and wiring 5RH.

[0046] As shown in Figure 9, the wiring 5 includes a flat conductive portion 51 made of a conductive material (metal such as Cu (copper)) and an insulating covering portion 52 that covers the conductive portion 51. As shown in Figure 9, the cross-sectional shape of the wiring 5 is rectangular, but as shown in Figure 17, it may be circular (concentric).

[0047] As shown in Figures 10 to 12, the wiring 5 is wrapped around the side of the main body 71 of the connection part 7, in a position sandwiched between the flange portion 72 and the flange portion 73. Furthermore, the wiring 5 has a tendency to curl (restoring force) in the direction that it wraps around the main body 71.

[0048] On the other hand, among the multiple through holes 711 formed in the main body 71, a notch 712 (Figures 6 and 10-12) is formed on the side of the main body 71 opposite to the through hole 711 through which the plug pin 8 connected to the wiring 5 wrapped around the main body 71 is inserted, and the main body 71 and the through hole 711 are in communication through the notch 712.

[0049] The end of the wiring 5 on the connection part 7 side is introduced into the through hole 711 from the side of the main body 71 via the notch 712. At the end of the wiring 5 introduced into the through hole 711, the covering part 52 is removed and the conductive part 51 is exposed, and the wiring 5 and the plug pin 8 are electrically connected when the conductive part 51 comes into contact with the plug pin 8. The conductive part 51 at the end of the wiring 5 is positioned to contact the inner side of the through hole 711, but it is preferable that the direction in which the conductive part 51 circulates and the direction in which the wiring 5 wraps around the side of the main body 71 are opposite to each other. This increases the frictional force between the wiring 5 and the main body 71 at the notch 712 and reduces the likelihood of the wiring 5 coming out of the main body 71.

[0050] On the other hand, at the end of the wiring 5 on the connecting terminal 4 side, the covering portion 52 is also removed, exposing the conductive portion 51, and the connecting terminal 4 and the wiring 5 are electrically connected when the conductive portion 51 comes into contact with the connecting terminal 4 (terminal portion 42).

[0051] For example, as shown in Figure 10, a notch 712 is positioned opposite the through hole 711A (first through hole) of the main body 71 of the connection part 7RA. The wiring 5RA is introduced into the through hole 711A via the notch 712, and the conductive part 51 exposed at the end of the wiring 5RA comes into contact with the plug pin 8RA that is inserted through the through hole 711A. The conductive part 51 is electrically connected to the plug pin 8RA, but is insulated from the plug pins 8RB-8RH that are inserted through the through holes 711B-711H (second through holes). On the other hand, the conductive part 51 exposed at the end of the wiring 5RA on the side of the connecting terminal 4RA is wrapped around the tip of the connecting terminal 4RA (terminal part 42) and fixed by welding or the like.

[0052] For example, as shown in Figure 11, a notch 712 is positioned opposite the through hole 711B (first through hole) of the main body 71 of the connection part 7RB. The wiring 5RB is introduced into the through hole 711B via the notch 712, and the conductive part 51 exposed at the end of the wiring 5RB comes into contact with the plug pin 8RB inserted through the through hole 711B. The conductive part 51 is electrically connected to the plug pin 8RB, but is insulated from the plug pins 8RBA, 8RC-8RH inserted through the through holes 711A, 711C-711H (second through holes). On the other hand, the conductive part 51 exposed at the end of the wiring 5RB on the side of the connecting terminal 4RB is wrapped around the tip of the connecting terminal 4RB (terminal part 42) and fixed by welding or the like.

[0053] For example, as shown in Figure 12, a notch 712 is positioned opposite the through hole 711H (first through hole) of the main body 71 of the connection part 7RH. The wiring 5RH is introduced into the through hole 711H via the notch 712, and the conductive part 51 exposed at the end of the wiring 5RH comes into contact with the plug pin 8RH that is inserted through the through hole 711H. The conductive part 51 is electrically connected to the plug pin 8RH, but is insulated from the plug pins 8RBA-8RG that are inserted through the through holes 711A-711G (second through holes). On the other hand, the conductive part 51 exposed at the end of the wiring 5RH on the side of the connecting terminal 4RH is wrapped around the tip of the connecting terminal 4RH (terminal part 42) and fixed by welding or the like.

[0054] Figure 13 is a plan view showing the arrangement of the connecting terminal 4, the connection part 7, and the wiring 5. Figure 13(a) shows the arrangement of the connecting terminal 4, the connection part 7, and the wiring 5 when the charge level of the stacked battery cell (battery cell 3) is approximately zero, and Figure 13(b) shows the arrangement of the connecting terminal 4, the connection part 7, and the wiring 5 when the charge level of the stacked battery cell (battery cell 3) is at a charge level corresponding to full charge.

[0055] As described above, the wiring 5 has a tendency to coil (restoring force) in the direction of wrapping around the connection part 7. Therefore, as shown in Figure 13(a), the portion of the wiring 5 that is unwound from the connection part 7, that is, the portion of the wiring 5 between the connecting terminal 4 and the connection part 7, is pulled in the X direction (the stacking direction of the battery cells 3).

[0056] On the other hand, as shown in Figure 13(b), when the stacked battery cell (battery cell 3) is charged, the stacked battery cell (battery cell 3) expands in the thickness direction (X direction), and the connecting terminal 4 fixed to the battery cell 3 moves toward the connection part 7 (+X direction). As a result, the portion of the wiring 5 that has been unwound from the connection part 7 is wound onto the connection part 7 by the amount that the connecting terminal 4 has moved toward the connection part 7, and the remaining portion continues to be pulled in approximately the X direction.

[0057] In this embodiment, the amount of wiring 5 wound onto the connection part 7 is maximized when the charge level of the stacked battery cell (battery cell 3) reaches the charge level corresponding to full charge (for example, 80%). However, the further a battery cell 3 is from the fixed end plate 21, the greater the change in its position in the X direction during charging. Therefore, when the charge level of the stacked battery cell (battery cell 3) is changed from approximately zero to the charge level corresponding to full charge, the amount of movement of the connecting terminal 4 is in the order of connecting terminal 4RA < connecting terminal 4RB < ... < connecting terminal 4RH, and the amount of wiring 5 wound onto the connection part is also in the order of wiring 5RA < wiring 5Rb < ... < wiring 5RH.

[0058] The voltage measuring means (not shown) detects the output voltage of battery cell 3A based on the voltage difference between external wiring 9LA (connecting terminal 4LA) and external wiring 9RA (connecting terminal 4RA) (see Figures 1 and 3, and the same applies hereafter).

[0059] The voltage measuring means (not shown) detects the output voltage of the battery cell 3B based on the voltage difference between the external wiring 9RB (connecting terminal 4RB) and the external wiring 9LA (connecting terminal 4LA).

[0060] The voltage measuring means (not shown) detects the output voltage of battery cell 3C based on the voltage difference between external wiring 9LB (connecting terminal 4LB) and external wiring 9RB (connecting terminal 4RB).

[0061] The voltage measuring means (not shown) detects the output voltage of the battery cell 3D based on the voltage difference between the external wiring 9RC (connecting terminal 4RC) and the external wiring 9LB (connecting terminal 4LB).

[0062] The voltage measuring means (not shown) detects the output voltage of the battery cell 3E based on the voltage difference between the external wiring 9LC (connecting terminal 4LC) and the external wiring 9RC (connecting terminal 4RC).

[0063] The voltage measuring means (not shown) detects the output voltage of battery cell 3F based on the voltage difference between external wiring 9RD (connecting terminal 4RD) and external wiring 9LC (connecting terminal 4LC).

[0064] The voltage measuring means (not shown) detects the output voltage of battery cell 3G based on the voltage difference between external wiring 9LD (connecting terminal 4LD) and external wiring 9RD (connecting terminal 4RD).

[0065] The voltage measuring means (not shown) detects the output voltage of the battery cell 3H based on the voltage difference between the external wiring 9RE (connecting terminal 4RE) and the external wiring 9LD (connecting terminal 4LD).

[0066] The voltage measuring means (not shown) detects the output voltage of the battery cell 3I based on the voltage difference between the external wiring 9LE (connecting terminal 4LE) and the external wiring 9RE (connecting terminal 4RE).

[0067] The voltage measuring means (not shown) detects the output voltage of the battery cell 3J based on the voltage difference between the external wiring 9RF (connection terminal 4RF) and the external wiring 9LE (connection terminal 4LE).

[0068] The voltage measuring means (not shown) detects the output voltage of the battery cell 3K based on the voltage difference between external wiring 9LF (connecting terminal 4LF) and external wiring 9RF (connecting terminal 4RF).

[0069] The voltage measuring means (not shown) detects the output voltage of the battery cell 3L based on the voltage difference between the external wiring 9RG (connecting terminal 4RG) and the external wiring 9LF (connecting terminal 4LF).

[0070] The voltage measuring means (not shown) detects the output voltage of battery cell 3M based on the voltage difference between external wiring 9LG (connecting terminal 4LG) and external wiring 9RG (connecting terminal 4RG).

[0071] The voltage measurement means (not shown) detects the output voltage of the battery cell 3N based on the voltage difference between the external wiring 9RH (connection terminal 4RH) and the external wiring 9LG (connection terminal 4LG).

[0072] [Center position of the laminated battery cell] Figure 14 shows the center position (Pn Δ , 0 , Δ ,

[0075] , 0 , , , , F , 0 , F , 0 , ,

[0076] ,

[0074] , ) of the laminated battery cell (battery cell 3) when the charge rate of the laminated battery cell (battery cell 3) is substantially zero and the center position (Pn F ) of the laminated battery cell (battery cell 3) when the charge rate of the laminated battery cell (battery cell 3) is the charge rate corresponding to full charge, and the relationship with the number of laminations (n) of the battery cell 3 in the laminated battery cell.

[0073] Here, for example, when the charge rate of the laminated battery cell (battery cell 3) is substantially zero, the thickness of the battery cell 3 is set to 20 [mm], and when the charge rate of the laminated battery cell (battery cell 3) is the charge rate corresponding to full charge, the thickness of the battery cell 3 is calculated as 24 [mm].

[0074] For example, when the number of laminations (n) of the battery cell 3 in the laminated battery cell is 10, regarding the center position (Pn) in the X direction of the laminated battery cell based on the position of the main surface on the laminated battery cell side of the fixed end plate 21, the center position (Pn 0 ) is 100 [mm] when the charge rate of the laminated battery cell (battery cell 3) is substantially zero, and the center position (PnF) is 120 [mm] when the charge rate of the laminated battery cell (battery cell 3) is the charge rate corresponding to full charge. Therefore, the difference (Pn Δ = Pn F - Pn<00000​​​​​​​​​​​​​​​ Therefore, it is difficult to apply the configuration in which the busbar 33 is fixed to the housing (for example, the housing that houses the battery cell 3), as in Patent Document 1, to a stacked battery cell related to an all-solid-state battery in which the center position (Pn) changes significantly, as in this embodiment.

[0077] Furthermore, even in configurations where the busbar 33 is not fixed to the enclosure, if the center position (Pn) moves significantly as described above, the voltage measurement wiring 5 connected to the busbar 33 needs to be set to a longer length to accommodate this movement. For this reason, the longer wiring 5 needs to be positioned so as not to interfere with the enclosure or external equipment.

[0078] However, in this embodiment, even when the stacked battery cell (battery cell 3) is expanded in the thickness direction (X direction) or contracted in the thickness direction as described above, the wiring 5 (the portion between the connecting terminal 4 and the connection part 7) is pulled in the stacking direction (X direction) of the stacked battery cell and maintains a linearly extended state, thus reducing interference with the housing or external equipment.

[0079] [Comparative Example] Figure 15 is a perspective view of the comparative example battery module 1A, where Figure 15(a) is a perspective view when the charge level of the stacked battery cell (battery cell 3) is at the charge level related to full charge, and Figure 15(b) is a perspective view when the charge level of the stacked battery cell (battery cell 3) is approximately zero. Figure 16 shows the case where a folded structure is provided to the wiring 5 shown in Figure 15.

[0080] As shown in Figure 15(a), the comparative example battery module 1A does not include the connection portion 7 (plug pin 8) of this embodiment. Also, the wiring 5 is connected to the tip of the connecting terminal 4, as in this embodiment, but is further fixed to the movable end plate 22. In the comparative example, the length of the connection portion of the wiring 5 to the connecting terminal 4 and the connection portion to the movable end plate 22 is set based on the distance between the tip of the connecting terminal 4 and the movable end plate 22 when the stacked battery cell (battery cell 3) is fully charged.

[0081] Therefore, as shown in Figure 15(b), when the stacked battery cell (battery cell 3) discharges and shrinks in the thickness direction, the wiring 5 bends so that it protrudes in a direction away from the side surface where the busbar 33 of the battery cell 3 (positive electrode tab 31, negative electrode tab 32 (Figure 1-4)) is located (Y direction). Therefore, in the comparative example, it is necessary to arrange other equipment in the adjacent space in the width direction (Y direction) of the battery cell 3 so as not to interfere with the bent wiring 5.

[0082] Therefore, as shown in Figure 16, it is also possible to apply a folding structure to the wiring 5 that folds in the stacking direction (X direction) of the stacked battery cells. However, when applying this folding structure, the wiring 5 needs to be made longer by the amount of the folding structure in the portion between the connecting terminal 4 of the wiring 5 and the movable end plate 22.

[0083] However, in this case, for example, when the stacked battery cell contracts, the wiring 5 is folded by the folded structure, but when the stacked battery cell expands, the folded structure is unfolded, and at that time the wiring 5 protrudes in the Y direction, which may interfere with the housing or other equipment.

[0084] On the other hand, in this embodiment, regardless of the expansion and contraction of the stacked battery cells, the wiring 5 (the portion between the connecting terminal 4 and the connection part 7) is pulled in a direction along the stacking direction (X direction) and maintains a linearly extended state, thereby reducing interference with the housing or other equipment.

[0085] [Differentiation] Figure 17 is a cross-sectional view of the wiring 5 of a modified example of the first embodiment. Figure 18 is a plan view showing the arrangement of the connecting terminal 4, the connecting part 7, and the modified wiring 5, where Figure 18(a) shows the arrangement of the connecting terminal 4, the connecting part 7, and the modified wiring 5 when the charge level of the stacked battery cell (battery cell 3) is approximately zero, and Figure 18(b) shows the arrangement of the connecting terminal 4, the connecting part 7, and the modified wiring 5 when the charge level of the stacked battery cell (battery cell 3) is at a charge level related to full charge.

[0086] As shown in Figure 17, the cross-sectional shape of the modified wiring 5 is circular, and it is composed of a conductive part 51 with a circular cross-sectional shape and a covering part 52 that covers its periphery, with the conductive part 51 and the covering part 52 being concentric.

[0087] As shown in Figure 18(a), the wiring 5 is attached to the connector 7. In Figures 18(a) and 18(b), the wiring 5 is wrapped around the connector 7 (main body 71), but it is not necessary to wrap it around the connector 7; it may be fixed with adhesive or the like at a position where it contacts the connector 7.

[0088] Furthermore, although the flange portions 72 and 73 of the connection portion 7 are not shown in Figures 18(a) and (b), they may be omitted if the wiring 5 is not wrapped around the connection portion 7.

[0089] The wiring 5 is introduced into the through hole 711 via the notch 712, and the covering portion 52 is removed at the end introduced into the through hole 711, exposing the conductive portion 51. The plug pin 8, which is inserted through the through hole 711, then comes into contact with the conductive portion 51, thereby electrically connecting the wiring 5 and the plug pin 8. In addition, the covering portion 52 is removed at the end of the wiring 5 on the side of the connecting terminal 4, exposing the conductive portion 51, which is then connected to the connecting terminal 4 by welding or the like.

[0090] A spring structure 5S is provided between the connecting terminal 4 and the connection part 7 of the wiring 5. The spring structure 5S has a spring-like coil shape relative to the wiring 5 and expands and contracts in the X direction. Furthermore, the natural length of the spring structure 5S in the X direction is set to be shorter than the length of the spring structure 5S in the X direction as shown in Figures 18(a) and 18(b).

[0091] Therefore, the spring structure 5S is constantly pulled in the X direction, constantly generating a restoring force that shortens the X-direction length of the portion between the connecting terminal 4 and the connection part 7 of the wiring 5, and the portion between the connecting terminal 4 and the connection part 7 of the wiring 5 maintains a state in which it is linearly extended along the X direction as a whole.

[0092] Therefore, as shown in Figure 18(b), even if the stacked battery cell is charged and the connecting terminal 4 moves in the +X direction, the spring structure 5S absorbs this movement, so the portion of the wiring 5 between the connecting terminal 4 and the connection part 7 continues to maintain a state of linear extension along the X direction as a whole. Therefore, interference of the wiring 5 with the housing or other equipment can be reduced in the same way as described above.

[0093] [Second Embodiment] Figure 19 is a side view of the battery module 1 of the second embodiment. Figure 20 is a top view of the battery module 1 of the second embodiment.

[0094] The battery module 1 of the second embodiment has a configuration in which the busbar 33 of the first embodiment is omitted. Also, except for the negative electrode tab 32 of battery cell 3A and the positive electrode tab 31 of battery cell 3N, the positive electrode tab 31 and negative electrode tab 32 of the stacked battery cells are bent into an L shape in plan view. Furthermore, one positive electrode tab 31 of two battery cells 3 that are adjacent to each other in the thickness direction and the other negative electrode tab 32 of two battery cells 3 that are adjacent to each other in the thickness direction are connected to each other by welding or the like and become one unit.

[0095] The connecting terminal 4 is connected to either the positive or negative tab 32 of the integrated positive and negative tabs 31 and negative tabs 32. By omitting the busbar 33 in this way, the number of parts can be reduced and costs can be controlled.

[0096] [Effects of this embodiment] The battery module 1 of this embodiment comprises a plurality of stacked battery cells 3, a plurality of connecting terminals 4 connected one-to-one to a busbar 33 that connects tabs (positive electrode tab 31, negative electrode tab 32) extending from the battery cells 3, or two adjacent tabs (positive electrode tab 31, negative electrode tab 32) in the stacking direction of the battery cells 3, a plurality of insulating connection parts 7 arranged in the same number as the connecting terminals 4 in a direction perpendicular to the stacking direction, and a plurality of connection parts 7 that are supported by simultaneously passing through the plurality of connection parts 7 while being insulated from each other, and are electrically connected to an external voltage measuring means (not shown). The device includes a plurality of plug pins 8, a coupling terminal 4 and a coupling portion 7, and a plurality of flexible wiring 5 for voltage measurement, wherein one of the plug pins 8 is electrically connected to a wiring 5 connected to one of the coupling portions 7, and is insulated from the wiring 5 connected to the other coupling portions 7, so that the plurality of plug pins 8 and the plurality of wiring 5 are electrically connected to each other on a one-to-one basis, and the wiring 5 is connected to the coupling terminal 4 in a state where it extends from the coupling portion 7 in a direction along the stacking direction.

[0097] With the above configuration, when the thickness of a stacked battery cell formed by stacking multiple battery cells 3 changes in the stacking direction due to charging and discharging, the position of the tabs (positive electrode tab 31, negative electrode tab 32) or busbars 33 changes in the thickness direction. However, since the wiring 5 is connected to the connecting terminal 4 in an extended state in the stacking direction, the connecting terminal 4 maintains an extended state in the stacking direction while absorbing the change in the position of the tabs (positive electrode tab 31, negative electrode tab 32) or busbars 33. Therefore, the wiring 5 for measuring the voltage of each battery cell 3 constituting the stacked battery cell can be compactly housed, increasing the volume density of the battery module 1 and reducing interference with the housing or external equipment that houses the stacked battery cell.

[0098] In this embodiment, the battery cell 3 is an all-solid-state battery that expands in the stacking direction (X direction) during charging and contracts in the stacking direction during discharge, and the wiring 5 is connected to the connecting terminal 4 in an extended state along the stacking direction from the connection part 7 after charging and after discharging of the battery cell 3.

[0099] With the above configuration, even when using a solid-state battery with a large expansion and contraction amount as the battery cell 3, the wiring 5 can be compactly arranged, increasing the volume density of the battery module 1 and reducing interference with the housing that houses the stacked battery cells or with external equipment.

[0100] In this embodiment, the wiring 5 is wrapped around the side of the connection part 7 (body 71), and the connection part 7 has a first through hole (through hole 711 (e.g., through hole 711A)) through which a plug pin 8 (e.g., plug pin 8RA) that is electrically connected to the wiring 5 (e.g., wiring 5RA) connected to the connection part 7 (e.g., connection part 7RA) passes, and a plug pin 8 (plug pins 8RB-8RH) that insulates the wiring 5 (wiring 5RA) connected to the connection part 7 (connection part 7RA) passes through. The wiring 5 (wiring 5RA) is electrically connected to the plug pin 8 (plug pin 8RA) by being introduced into the first through hole (through hole 711 (through hole 711B-711H)) via the notch 712, and the end of the wiring 5 (wiring 5RA) on the side of the connection part 7 (connection part 7RA) is introduced into the first through hole (through hole 711 (through hole 711A)) via the notch 712, and the conductive part 51 comes into contact with the plug pin 8 (plug pin 8RA).

[0101] With the above configuration, the connection part 7 and the plug pin 8 are reliably electrically connected on a one-to-one basis, and the support structure of the connection part 7 by the plug pin 8 can be compactly housed.

[0102] In this embodiment, the wiring 5 is connected to the connecting terminal 4 in a manner that it is unwound from the connection part 7 and has a restoring force in a direction that causes it to wrap around the side surface of the connection part 7 (main body 71).

[0103] With the above configuration, after charging and discharging the battery cell 3, the wiring 5 that connects to the connecting terminal 4 in a state where it extends from the connection part 7 in a direction along the stacking direction can be constructed in a simple manner.

[0104] In this embodiment, the connection part 7 has a first through hole (through hole 711 (e.g., through hole 711A)) through which a plug pin 8 (e.g., plug pin 8RA) that is electrically connected to the wiring 5 (e.g., wiring 5RA) connected to the connection part 7 (e.g., connection part 7RA) passes, and a plurality of second through holes (through holes 711 (through holes 711B-711H)) through which plug pins 8 (plug pins 8RB-8RH) that are insulated from the wiring 5 (wiring 5RA) connected to the connection part 7 (connection part 7RA) pass, and the connection part 7 (connection part 7RA) (main body) The wiring 5 (wiring 5RA) includes a notch 712 that connects the side of 71) and the first through hole (through hole 711 (through hole 711A)), and the end of the wiring 5 (wiring 5RA) on the side of the connection part 7 (connection part 7RA) is introduced into the first through hole (through hole 711 (through hole 711A)) via the notch 712, and the conductive part 51 comes into contact with the plug pin 8 (plug pin 8RA), thereby electrically connecting the wiring 5 (wiring 5RA) with the plug pin 8 (plug pin 8RA), and the portion of the wiring 5 between the connecting terminal 4 and the connection part 7 has a spring shape (spring structure 5S) that expands and contracts in the stacking direction.

[0105] With the above configuration, after charging and discharging the battery cell 3, the wiring 5 that connects to the connecting terminal 4 in a state where it extends from the connection part 7 in a direction along the stacking direction can be constructed in a simple manner.

[0106] In this embodiment, the multiple connection parts 7 (connection parts 7RA-7RH) are arranged to be perpendicular to the stacking direction (X direction) and aligned in the lateral direction (Z direction) along the side surface to which the tabs (positive electrode tab 31, negative electrode tab 32) of the battery cell 3 extend. The connection position between the connecting terminal 4 and the wiring 5 is located in the same position in the lateral direction (Z direction) as the connection part 7 to which the wiring 5 is connected.

[0107] With the above configuration, the battery module 1 can be made more compact by avoiding the connection part 7 (connection parts 7RA-7RH) protruding in the direction perpendicular to the stacking direction (X direction) and the lateral direction (Z direction) (Y direction). In addition, since the longitudinal directions of the multiple wires 5 are arranged parallel to the X direction, entanglement of the multiple wires 5 can be prevented.

[0108] In this embodiment, the pressurizing mechanism 23 further includes a pressurizing section (rod 231, actuator 232) that pressurizes a plurality of battery cells 3 from the stacking direction (X direction), and a fixing section 233 to which the pressurizing section (rod 231, actuator 232) is fixed, and the plug pin 8 is supported by the fixing section 233 (via the first support section 61 and the second support section 62).

[0109] With the above configuration, the plug pin 8 and the connection part 7 can be supported with a simple structure.

[0110] Although embodiments of the present invention have been described above, these embodiments represent only a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. Furthermore, the above embodiments can be combined as appropriate. [Explanation of Symbols]

[0111] 1 Battery module, 3 Battery cells, 31 Positive tab, 32 Negative tab, 33 Busbar, 4 Connector terminal, 5 Wiring, 7 Connection part, 8 Plug pins

Claims

1. Multiple stacked battery cells, Multiple connecting terminals connected one-to-one to a busbar that connects two adjacent tabs in the stacking direction of the battery cells, Multiple insulating connection parts are arranged in the same number as the connecting terminals in a direction perpendicular to the stacking direction, Multiple plug pins are supported such that multiple of the aforementioned connection parts are simultaneously penetrated while being insulated from each other, and are electrically connected to an external voltage measuring means. The connecting terminals and the connecting portion are connected one-to-one, and the wiring includes a plurality of flexible wirings for voltage measurement, One of the multiple plug pins is electrically connected to the wiring connected to one of the multiple connection parts, and is insulated from the wiring connected to the other connection parts of the multiple plug pins, so that the multiple plug pins and the multiple wirings are electrically connected to each other on a one-to-one basis. The aforementioned wiring is connected to the connecting terminal of the battery module, extending from the connection portion in a direction along the stacking direction.

2. The aforementioned battery cell is an all-solid-state battery that expands in the stacking direction during charging and contracts in the stacking direction during discharge. The battery module according to claim 1, wherein the wiring is connected to the connecting terminal in a state that extends from the connection portion in a direction along the stacking direction after the battery cell has been charged and discharged.

3. The wiring is wrapped around the connection part so as to encircle the side of the connection part. The aforementioned connection part is A first through-hole through which a plug pin, among a plurality of plug pins, is electrically connected to the wiring connected to the connection part, A plurality of second through holes through which each of the plug pins, which is insulated from the wiring connected to the connection part, passes, The connection portion includes a notch that connects the side surface of the connection portion and the first through hole, The battery module according to claim 1 or claim 2, wherein the end of the wiring on the connection side is introduced into the first through hole through the notch and comes into contact with the plug pin, thereby electrically connecting the wiring to the plug pin.

4. The battery module according to claim 3, wherein the wiring is connected to the connecting terminal in a manner that it is unwound from the connection part and has a restoring force in a direction that causes it to wrap around the side surface of the connection part.

5. The aforementioned connection part is A first through-hole through which a plug pin, among a plurality of plug pins, is electrically connected to the wiring connected to the connection part, A plurality of second through holes through which each of the plug pins, which is insulated from the wiring connected to the connection part, passes, The connection portion includes a notch that connects the side surface of the connection portion and the first through hole, The end of the wiring on the connection side is introduced into the first through-hole through the notch and comes into contact with the plug pin, thereby electrically connecting the wiring to the plug pin. The battery module according to claim 1 or claim 2, wherein the portion of the wiring between the connecting terminal and the connection portion has a spring shape that expands and contracts in the stacking direction.

6. The multiple connection portions are arranged so as to be perpendicular to the stacking direction and aligned in a lateral direction along the side surface from which the tabs of the battery cell extend. The battery module according to claim 1 or 2, wherein the connection position between the connecting terminal and the wiring is located at the same position in the lateral direction as the connection portion to which the wiring is connected.

7. The pressurizing mechanism further includes a pressurizing section for pressurizing a plurality of battery cells from the stacking direction, and a fixing section to which the pressurizing section is fixed. The battery module according to claim 1 or claim 2, wherein the plug pin is supported by the fixed portion.

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