Battery

Abstract

To provide a battery capable of suppressing an increase in an interval between a plurality of cell stacks arranged side by side.SOLUTION: A battery includes first and second cell stacks each having a rectangular parallelepiped shape in which a plurality of rectangular cells each having a terminal provided on a longitudinal end surface are stacked. The first and second cell stacks are juxtaposed so that a first end and a second end in a stacking direction correspond to each other. A root part of a first end bus bar is fixed to the terminal of the rectangular cells located closest to the first end in the first cell stack, and the root part of a second end bus bar is fixed to the terminal of the rectangular cells located closest to the first end in the second cell stack. A tip end part of the second end bus bar is disposed so as to be shifted downward and toward the first end side with respect to the tip end part of the first end bus bar, and the tip end part of the first end bus bar and the tip end part of the second end bus bar are disposed side by side in the stacking direction of the plurality of rectangular cells.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] In conventional batteries, terminals are provided on the top surface of each stacked prismatic cell. In recent years, as disclosed in Patent Document 1, batteries have been developed in which terminals are provided on the longitudinal end surfaces of each stacked prismatic cell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 0302533 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have developed a battery with multiple cell stacks arranged side by side. In the battery described above, in which terminals are provided on the longitudinal end faces of the prismatic cells, end bus bars for external connection are fixed to the terminals of the prismatic cells located at the ends in the stacking direction. This has led to a problem in which the end bus bars interfere with each other, increasing the gap between the arranged cell stacks.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a battery that can suppress an increase in the gap between a plurality of cell stacks arranged in parallel. [Means for solving the problem]

[0006] A battery according to one aspect of the present disclosure includes: A battery including first and second rectangular parallelepiped cell stacks in which a plurality of rectangular cells having terminals on their longitudinal end faces are stacked, the first and second cell stacks are arranged side by side such that first and second ends in the stacking direction correspond to each other, a root portion of a first end bus bar is fixed to a terminal of a rectangular cell located closest to the first end in the first cell stack; a base portion of a second end bus bar is fixed to a terminal of a rectangular cell located closest to the first end in the second cell stack; a tip end portion of the second end bus bar is disposed below the tip end portion of the first end bus bar and shifted toward the first end, The tip end portion of the first end bus bar and the tip end portion of the second end bus bar are arranged side by side in the stacking direction of the plurality of rectangular cells.

[0007] In the battery of the present disclosure, the root portion of a first end bus bar is fixed to the terminal of the rectangular cell located closest to the first end in the first cell stack, and the root portion of a second end bus bar is fixed to the terminal of the rectangular cell located closest to the first end in the second cell stack, and the tip portion of the second end bus bar is positioned below and offset toward the first end relative to the tip portion of the first end bus bar, and the tip portions of the first end bus bar and the second end bus bar are arranged side by side in the stacking direction of the multiple rectangular cells. Therefore, the opposing first and second end bus bars do not interfere with each other, and an increase in the gap between the first and second cell stacks arranged side by side can be suppressed.

[0008] A tip end portion of the first end bus bar may be placed on a first support base fixed to the first end of the first cell stack, and a tip end portion of the second end bus bar may be placed on a second support base fixed to the first end of the second cell stack. With this configuration, the positions of the tip ends of the first and second end bus bars can be stabilized.

[0009] A threaded rod provided in the first support base may be inserted into a through hole provided in the tip of the first end bus bar, and a threaded rod provided in the second support base may be inserted into a through hole provided in the tip of the second end bus bar. With this configuration, the positions of the tip ends of the first and second end bus bars can be further stabilized.

[0010] The first support base may be fixed to an end plate at the first end of the first cell stack, and the second support base may be fixed to an end plate at the first end of the second cell stack.

[0011] The first support base may be bolted to an end plate at the first end of the first cell stack, and the second support base may be bolted to an end plate at the first end of the second cell stack, and the end plate at the first end of the first cell stack and the end plate at the first end of the second cell stack may be offset in the stacking direction. With this configuration, the bolts fastening the first and second support bases do not interfere with each other, and an increase in the distance between the first and second cell stacks arranged side by side can be suppressed. [Effects of the Invention]

[0012] The present disclosure makes it possible to provide a battery that can suppress an increase in the gap between multiple cell stacks arranged in parallel. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic perspective view showing a battery according to a first embodiment. [Figure 2] 1 is a schematic perspective view showing a battery according to a first embodiment. [Figure 3] FIG. 2 is a schematic side view of the cell stack CS1 on the side opposite to the cell stack CS2. [Figure 4] FIG. 2 is a schematic side view of the cell stack CS2 on the side opposite to the cell stack CS1. [Figure 5]10 is a schematic side view showing the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 on the first end side. FIG. [Figure 6] 10 is a schematic plan view showing the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 on the first end side. FIG. [Figure 7] 10 is a schematic side view showing the positional relationship between the end bus bar EB12 of the cell stack CS1 and the end bus bar EB22 of the cell stack CS2 on the second end side. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, specific embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings have been simplified appropriately for clarity of explanation.

[0015] (First embodiment) <Battery configuration> First, the configuration of the battery according to the first embodiment will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a schematic perspective view showing the battery according to the first embodiment. Fig. 2 is a schematic perspective view showing the battery according to the first embodiment. Fig. 3 is a schematic side view of the cell stack CS1 on the side opposite the cell stack CS2. Fig. 4 is a schematic side view of the cell stack CS2 on the side opposite the cell stack CS1.

[0016] The battery according to the present embodiment is used, for example, in a vehicle. The vehicle in which the battery according to the present embodiment is mounted is not particularly limited, but examples thereof include electric vehicles, hybrid vehicles, fuel cell vehicles, and the like that can be driven by power supplied from the battery. Naturally, the right-handed XYZ Cartesian coordinate system shown in Figures 1 to 4 and other figures is for the convenience of explaining the positional relationships of the components. In Figure 1 and other figures, the positive direction of the Z axis is normally vertically upward, and the XY plane is the horizontal plane, which is common to all figures.

[0017] 1 and 2, the battery according to the first embodiment includes cell stacks CS1 and CS2. As shown in Fig. 1 and 2, the cell stacks CS1 and CS2 extend in the X-axis direction. As shown in Fig. 1 and 2, the cell stacks CS1 and CS2 are arranged side by side in the Y-axis direction inside a case (not shown) so that their first ends (ends on the negative X-axis direction) and second ends (ends on the negative X-axis direction) in the stacking direction (X-axis direction) correspond to each other.

[0018] 1 and 2, the distance between the cell stacks CS1 and CS2 is drawn wider than it actually is to clearly show the configuration of each of the cell stacks CS1 and CS2. Also, in FIG. 1 and 2, the cell stacks CS1 and CS2 are drawn shifted in the X-axis direction from their actual positions.

[0019] As shown in Figures 1 and 2, cell stacks CS1 and CS2 have substantially the same configuration, each including a plurality of rectangular cells C1 to C6 and bus bars B1 to B5. As shown in Figure 3, cell stack CS1 includes end plates EP1 and EP2 and end bus bars EB11 and EB12, which are not shown in Figures 1 and 2. Furthermore, as shown in Figure 4, cell stack CS2 includes end plates EP1 and EP2 and end bus bars EB21 and EB22, which are not shown in Figures 1 and 2.

[0020] 1 and 2, the prismatic cells C1 to C6 are rectangular parallelepiped cells extending in the Y-axis direction. The prismatic cells C1 to C6 are stacked in the thickness direction (X-axis direction) to form cell stacks CS1 and CS2. The prismatic cells C1 to C6 are secondary batteries such as lithium-ion batteries or nickel-metal hydride batteries.

[0021] Note that the cell stacks CS1 and CS2 are shown in a simplified manner in Figures 1 and 2. The cell stacks CS1 and CS2 shown in Figures 1 and 2 are composed of six prismatic cells C1 to C6, but are usually composed of more prismatic cells. On the other hand, the number of prismatic cells that compose the cell stacks CS1 and CS2 is not particularly limited, as long as it is plural. Furthermore, a heat insulating plate or a spacer for adjusting the gap may be inserted between adjacent rectangular cells.

[0022] As shown in Fig. 1, in the cell stacks CS1 and CS2, a positive electrode terminal PT1 is provided on one longitudinal end face (the end face on the negative Y-axis side) of the prismatic cell C1. Although not particularly limited, the positive electrode terminal PT1 shown in Fig. 2 has a rectangular shape when viewed in the XZ plane and is provided so as to protrude outward from the end face of the prismatic cell C1. The positive electrode terminal PT1 shown in Fig. 1 is provided on the upper side (the positive Z-axis side) of the end face of the prismatic cell C1. The positive electrode terminal PT1 is made of a metal material such as copper, which has excellent conductivity.

[0023] Similarly, as shown in FIG. 1, a negative electrode terminal NT2 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of prismatic cell C2 adjacent to prismatic cell C1. A positive electrode terminal PT3 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of prismatic cell C3 adjacent to prismatic cell C2. A negative electrode terminal NT4 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of prismatic cell C4 adjacent to prismatic cell C3. A positive electrode terminal PT5 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of prismatic cell C5 adjacent to prismatic cell C4. A negative electrode terminal NT6 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of prismatic cell C6 adjacent to prismatic cell C5.

[0024] As shown in FIG. 1, the negative electrode terminal NT2 of the prismatic cell C2, the positive electrode terminal PT3 of the prismatic cell C3, the negative electrode terminal NT4 of the prismatic cell C4, the positive electrode terminal PT5 of the prismatic cell C5, and the negative electrode terminal NT6 of the prismatic cell C6 have the same shape as the positive electrode terminal PT1 of the prismatic cell C1 and are arranged in the same manner.

[0025] On the other hand, as shown in Fig. 2, in the cell stacks CS1 and CS2, a negative electrode terminal NT1 is provided on the other longitudinal end face (end face on the Y-axis positive side) of the prismatic cell C1. Although not particularly limited, the negative electrode terminal NT1 shown in Fig. 2 has a rectangular shape in the XZ plane, similar to the positive electrode terminal PT1 shown in Fig. 1, and is provided so as to protrude outward from the end face of the prismatic cell C1. Furthermore, similar to the positive electrode terminal PT1 shown in Fig. 1, the negative electrode terminal NT1 shown in Fig. 2 is provided on the upper side (Z-axis positive side) of the end face of the prismatic cell C1. Similar to the positive electrode terminal PT1, the negative electrode terminal NT1 is made of a metal material such as copper, which has excellent conductivity.

[0026] Similarly, as shown in FIG. 2, a positive electrode terminal PT2 is provided on the other longitudinal end surface (the end surface on the positive Y-axis direction) of prismatic cell C2 adjacent to prismatic cell C1. A negative electrode terminal NT3 is provided on the other longitudinal end surface (the end surface on the positive Y-axis direction) of prismatic cell C3 adjacent to prismatic cell C2. A positive electrode terminal PT4 is provided on the other longitudinal end surface (the end surface on the positive Y-axis direction) of prismatic cell C4 adjacent to prismatic cell C3. A negative electrode terminal NT5 is provided on the other longitudinal end surface (the end surface on the positive Y-axis direction) of prismatic cell C5 adjacent to prismatic cell C4. A positive electrode terminal PT6 is provided on the other longitudinal end surface (the end surface on the positive Y-axis direction) of prismatic cell C6 adjacent to prismatic cell C5.

[0027] As shown in FIG. 2, the positive electrode terminal PT2 of the prismatic cell C2, the negative electrode terminal NT3 of the prismatic cell C3, the positive electrode terminal PT4 of the prismatic cell C4, the negative electrode terminal NT5 of the prismatic cell C5, and the positive electrode terminal PT6 of the prismatic cell C6 have the same shape as the negative electrode terminal NT1 of the prismatic cell C1 and are arranged in the same manner.

[0028] As shown in FIG. 1, on one end face (the end face on the negative Y-axis direction) of the cell stack CS1, the positive electrode terminal PT1 of adjacent prismatic cell C1 and the negative electrode terminal NT2 of adjacent prismatic cell C2 are electrically connected by a plate-shaped bus bar B1. Similarly, the positive electrode terminal PT3 of adjacent prismatic cell C3 and the negative electrode terminal NT4 of adjacent prismatic cell C4 are electrically connected by a plate-shaped bus bar B3. Similarly, the positive electrode terminal PT5 of adjacent prismatic cell C5 and the negative electrode terminal NT6 of adjacent prismatic cell C6 are electrically connected by a plate-shaped bus bar B5.

[0029] 2 and 3, on the other end face (the end face on the positive side of the Y axis) of the cell stack CS1, the positive electrode terminal PT2 of adjacent prismatic cell C2 and the negative electrode terminal NT3 of adjacent prismatic cell C3 are electrically connected by a plate-shaped bus bar B2. Similarly, the positive electrode terminal PT4 of adjacent prismatic cell C4 and the negative electrode terminal NT5 of adjacent prismatic cell C5 are electrically connected by a plate-shaped bus bar B4. In this way, in the cell stack CS1 shown in FIGS. 1 and 2, the prismatic cells C1 to C6 are connected in series by the bus bars B1 to B5.

[0030] As shown in Fig. 3, the base of the end bus bar EB11 is fixed to the negative terminal NT1 of the prismatic cell C1 of the cell stack CS1. Also, as shown in Fig. 3, the base of the end bus bar EB12 is fixed to the positive terminal PT6 of the prismatic cell C6 of the cell stack CS1. The end bus bars EB11 and EB12 of the cell stack CS1 will be described in detail later.

[0031] 1 and 4, on one end surface (the end surface on the negative Y-axis direction) of cell stack CS2, unlike cell stack CS1, the negative electrode terminal NT2 of adjacent prismatic cell C2 and the positive electrode terminal PT3 of adjacent prismatic cell C3 are electrically connected by a plate-shaped bus bar B2. Similarly, the negative electrode terminal NT4 of adjacent prismatic cell C4 and the positive electrode terminal PT5 of adjacent prismatic cell C5 are electrically connected by a plate-shaped bus bar B4.

[0032] As shown in FIG. 2, at the other end surface (the end surface on the positive side of the Y axis) of the cell stack CS2, unlike the cell stack CS1, the negative electrode terminal NT1 of adjacent prismatic cell C1 and the positive electrode terminal PT2 of adjacent prismatic cell C2 are electrically connected by a plate-shaped bus bar B1. Similarly, the negative electrode terminal NT3 of adjacent prismatic cell C3 and the positive electrode terminal PT4 of adjacent prismatic cell C4 are electrically connected by a plate-shaped bus bar B3. Similarly, the negative electrode terminal NT5 of adjacent prismatic cell C5 and the positive electrode terminal PT6 of adjacent prismatic cell C6 are electrically connected by a plate-shaped bus bar B5. In this way, in the cell stack CS2 shown in FIGS. 1 and 2, the prismatic cells C1 to C6 are also connected in series by the bus bars B1 to B5.

[0033] As shown in Fig. 4, the base of the end bus bar EB21 is fixed to the positive terminal PT1 of the prismatic cell C1 of the cell stack CS2. Also, as shown in Fig. 4, the base of the end bus bar EB22 is fixed to the negative terminal NT6 of the prismatic cell C6 of the cell stack CS2. The end bus bars EB21 and EB22 of the cell stack CS2 will be described in detail later.

[0034] 1 and 2 are bus bars that connect the rectangular cells C1 to C6 to each other. The bus bars B1 to B5 have the same configuration, so only the bus bar B1 will be described. 1 and 2, the busbar B1 is a plate-like member that electrically connects the terminals (positive terminal PT1 or negative terminal NT1) of adjacent prismatic cells C1 and C2 (negative terminal NT2 or positive terminal PT2). The busbar B1 is made of a metal material such as copper, which has excellent electrical conductivity.

[0035] 1 and 2, the busbar B1 is, for example, a rectangular plate-like member when viewed in the XZ plane. The busbar B1 is provided so as to cover substantially the entire terminals of the prismatic cell C1 (positive electrode terminal PT1 or negative electrode terminal NT1) and the terminals of the prismatic cell C2 (negative electrode terminal NT2 or positive electrode terminal PT2). The busbar B1 has a pair of welds WP1 and WP2 welded to the terminals of the adjacent prismatic cell C1 and the prismatic cell C2, respectively.

[0036] Although not particularly limited, the welded portions WP1 and WP2 shown in FIGS. 1 and 2 are provided on both ends in the X-axis direction on the lower side (negative Z-axis side) of the bus bar B1. Here, FIGS. 1 and 2 show the welded portions WP1 and WP2 before welding. The welded portions WP1 and WP2 shown in FIGS. 1 and 2 are countersunk and have a thinner plate thickness than other regions. Furthermore, the welded portions WP1 and WP2 shown in FIGS. 1 and 2 have a circular shape when viewed in the XZ plane and have a through-hole in the center.

[0037] While the welding method is not particularly limited, for example, in the case of the bus bar B1 of the cell stack CS1 shown in Fig. 1, a laser beam is applied to the weld WP1 from the negative side of the Y axis, thereby welding the bus bar B1 to the positive terminal PT1 of the prismatic cell C1 at the weld WP1. Similarly, a laser beam is applied to the weld WP2 from the negative side of the Y axis, thereby welding the bus bar B1 to the negative terminal NT2 of the prismatic cell C2 at the weld WP2.

[0038] 3 and 4, end plate EP1 is disposed at the end of the stacked prismatic cells C1 to C6 on the negative X-axis direction side. End plate EP2 is disposed at the end of the stacked prismatic cells C1 to C6 on the positive X-axis direction side. In other words, end plates EP1 and EP2 press and restrain the stacked prismatic cells C1 to C6 from both ends in the stacking direction (X-axis direction). The end plates EP1 and EP2 are made of a metal material such as aluminum.

[0039] 3, a support base SS1 that supports the tip ends of end bus bars EB11 and EB12 is fixed to the Y-axis positive end faces of end plates EP1 and EP2 of cell stack CS1 with bolts BT1 via connecting members CM1. More specifically, the base of connecting member CM1 is fixed to end plates EP1 and EP2 with bolts BT1, and the support base SS1 is fixed to the tip of connecting member CM1.

[0040] 4, a support base SS2 that supports the tip ends of the end bus bars EB21 and EB22 is fixed to the Y-axis negative end faces of the end plates EP1 and EP2 of the cell stack CS2 with bolts BT2 via connecting members CM2. More specifically, the base of the connecting member CM2 is fixed to the end plates EP1 and EP2 with bolts BT1, and the support base SS1 is fixed to the tip of the connecting member CM2.

[0041] 4, the support base SS2 is provided so as to protrude outside the cell stack CS2, that is, further toward the negative X-axis direction than end plate EP1 or further toward the positive X-axis direction than end plate EP2. Therefore, connecting members CM2 that connect the support base SS2 to the end plates EP1 and EP2 are provided so as to protrude in the X-axis direction from the end plates EP1 and EP2.

[0042] Here, the end bus bars EB11 and EB12 included in the cell stack CS1 shown in FIG. 3 and the end bus bars EB21 and EB22 included in the cell stack CS2 shown in FIG. 4 have different shapes. The number of cell stacks included in the battery according to this embodiment may be any number, and is not limited to 2. For example, the battery according to this embodiment may include multiple pairs of cell stacks CS1, CS2.

[0043] <Detailed configuration of end bus bars> Next, with reference to FIGS. 3 and 4, the detailed configurations of the end bus bars (first end bus bars) EB11 and EB12 of the cell stack CS1 and the end bus bars (second end bus bars) EB21 and EB22 of the cell stack CS2 will be described. Although FIGS. 3 and 4 are side views, for ease of understanding, the end bus bars EB11 and EB12 of the cell stack CS1 and the end bus bars EB21 and EB22 of the cell stack CS2 are displayed as dots.

[0044] While the bus bars B1 to B5 shown in Figures 1 and 2 are bus bars that connect the rectangular cells C1 to C6 to one another, the end bus bars EB11 and EB12 shown in Figure 3 are bus bars that connect the cell stack CS1 to the outside. Similarly, the end bus bars EB21 and EB22 shown in Figure 4 are bus bars that connect the cell stack CS2 to the outside. Like the bus bars B1 to B5, the end bus bars EB11, EB12, EB21, and EB22 are all plate-like members made of a metal material such as copper that has excellent conductivity.

[0045] First, the end bus bars EB11 and EB12 of the cell stack CS1 will be described with reference to Fig. 3. As described above, Fig. 3 shows the side surface of the cell stack CS1 facing the cell stack CS2. In other words, the end bus bars EB11 and EB12 are provided on the side surface of the cell stack CS1 facing the cell stack CS2.

[0046] 3, the base of the end bus bar EB11 is fixed to the terminal of the rectangular cell C1 located closest to the first end (negative side of the X-axis) in the cell stack (first cell stack) CS1, that is, the negative terminal NT1. The fixing method is not particularly limited, but may be, for example, welding.

[0047] The end bus bar EB11 extends above the negative terminal NT1 (positive Z-axis direction) and bends below the upper surface of the prismatic cell C1 toward the positive Y-axis direction so that its main surface is parallel to the XY plane. The tip of the end bus bar EB11 extending toward the end plate EP1 (negative X-axis direction) is placed on a support base (first support base) SS1 fixed to the end plate EP1. The first end of the cell stack CS1 may be the positive X-axis side, and the second end may be the negative X-axis side.

[0048] Here, Fig. 5 is a schematic side view showing the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 at the first end side, and Fig. 6 is a schematic plan view showing the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 at the first end side. In FIG. 5, the end bus bar EB11 and other components that make up the cell stack CS1 are indicated by two-dot chain lines.

[0049] As shown in Fig. 6, the support surface of the support base SS1 is, for example, rectangular in shape when viewed in the XY plane. As shown in Fig. 3 and Fig. 6, a stud (threaded rod) ST1 extending in the Z-axis direction is provided in the center of the support surface of the support base SS1. The stud ST1 provided in the support base SS1 is inserted into a through-hole provided in the tip of the end bus bar EB11 placed on the support base SS1.

[0050] As shown in Fig. 3, the end bus bar EB12 has a shape that is mirror-symmetrical to the end bus bar EB11 with respect to the YZ plane. Specifically, as shown in Fig. 3, the base portion of the end bus bar EB12 is fixed to the terminal of the rectangular cell C6 located closest to the second end side (the positive side of the X axis) in the cell stack CS1, i.e., the positive terminal PT6.

[0051] The end bus bar EB12 extends above the positive electrode terminal PT6 (positive Z-axis direction) and bends below the upper surface of the rectangular cell C6 toward the positive Y-axis direction so that its main surface is parallel to the XY plane. The tip of the end bus bar EB12 extending toward the end plate EP2 (positive X-axis direction) is placed on a support base SS1 fixed to the end plate EP2.

[0052] Here, the support base SS1 fixed to the end plate EP2 has the same shape as the support base SS1 fixed to the end plate EP1, and is arranged in a mirror-symmetrical relationship with the support base SS1 fixed to the end plate EP1 in the YZ plane. As with the end bus bar EB11, a stud ST1 provided on the support base SS1 is inserted into a through hole provided at the tip of the end bus bar EB12 placed on the support base SS1.

[0053] Next, the end bus bars EB21 and EB22 of the cell stack CS2 will be described with reference to Fig. 4. As described above, Fig. 4 shows the side surface of the cell stack CS2 facing the cell stack CS1. In other words, the end bus bars EB21 and EB22 are provided on the side surface of the cell stack CS2 facing the cell stack CS1.

[0054] As shown in Fig. 4, the base of the end bus bar EB21 is fixed to the terminal of the rectangular cell C1 located closest to the first end (negative X-axis side) in the cell stack (second cell stack) CS2, i.e., the positive terminal PT1. The end bus bar EB21 is bent downward (negative Z-axis side) from the positive terminal PT1 so that its main surface is parallel to the XY plane. The tip of the end bus bar EB21, which extends toward the end plate EP1 (negative X-axis side), is placed on a support base (second support base) SS2 fixed to the end plate EP1.

[0055] As shown in Fig. 4, the support base SS2 is provided outside the cell stack CS2, i.e., protruding further in the negative X-axis direction than the end plate EP1. Therefore, a connecting member CM2 that connects the support base SS2 to the end plate EP1 extends from the end plate EP1 in the negative X-axis direction. In contrast, the support base SS1 shown in Fig. 3 is provided inside the cell stack CS1, i.e., on the end plate EP1.

[0056] As shown in Fig. 6, the support surface of the support base SS2 is also rectangular in the XY plane. As shown in Fig. 4 and Fig. 6, a stud ST2 extending in the Z-axis direction is provided in the center of the support surface of the support base SS2. The stud ST2 provided in the support base SS2 is inserted into a through-hole provided in the tip of the end bus bar EB21 placed on the support base SS2.

[0057] As shown in Fig. 4, the end bus bar EB22 has a shape that is mirror-symmetrical to the end bus bar EB21 with respect to the YZ plane. Specifically, as shown in Fig. 4, the base of the end bus bar EB22 is fixed to the terminal of the rectangular cell C6 located closest to the second end (the positive X-axis side) in the cell stack CS2, i.e., the negative terminal NT6. The end bus bar EB22 is bent below the negative terminal NT6 toward the negative Y-axis so that its main surface is parallel to the XY plane. The tip of the end bus bar EB21, which extends toward the end plate EP2 (the negative X-axis side), is placed on a support base SS2 fixed to the end plate EP2.

[0058] Here, the support base SS2 fixed to the end plate EP2 has the same shape as the support base SS2 fixed to the end plate EP1, and is arranged in a mirror-symmetrical relationship with the support base SS2 fixed to the end plate EP1 with respect to the YZ plane.

[0059] 4, the support base SS2 fixed to the end plate EP2 is provided so as to protrude outward from the cell stack CS2, i.e., further in the positive direction of the X-axis than the end plate EP2. Therefore, a connecting member CM2 that connects the support base SS2 to the end plate EP2 extends from the end plate EP2 in the positive direction of the X-axis. Similarly to the end bus bar EB21, an end bus bar EB22 is placed on the support base SS2, and a stud ST2 provided on the support base SS2 is inserted into a through-hole provided at the tip of the end bus bar EB22.

[0060] <Arrangement relationship between end bus bar EB11 and end bus bar EB21 on the first end side> Here, with reference to FIGS. 5 and 6, the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 on the first end side (X-axis negative direction side) will be described.

[0061] As shown in Fig. 5, the tip of end bus bar EB21 is arranged below and shifted toward the first end (negative X-axis direction) with respect to the tip of end bus bar EB11. Also, as shown in Fig. 6, the tip of end bus bar EB11 and the tip of end bus bar EB21 are arranged side by side in the stacking direction of rectangular cells C1 to C6. Therefore, the opposing end bus bars EB11 and EB21 do not interfere with each other, and it is possible to prevent an increase in the gap between the juxtaposed cell stacks CS1 and CS2.

[0062] 5 and 6, the tip of end bus bar EB11 is placed on a support base SS1 fixed to end plate EP1 of cell stack CS1. The tip of end bus bar EB21 is placed on a support base SS2 fixed to end plate EP1 of cell stack CS2. The support bases SS1 and SS2 stabilize the positions of the tip of end bus bars EB11 and EB21. The support bases SS1 and SS2 are not essential.

[0063] As described above, the stud ST1 provided on the support base SS1 is inserted into a through hole provided at the tip of the end bus bar EB11. Also, the stud ST2 provided on the support base SS2 is inserted into a through hole provided at the tip of the end bus bar EB21. This configuration further stabilizes the positions of the tips of the end bus bars EB11 and EB21.

[0064] 5 and 6, the end plate EP1 of the cell stack CS1 and the end plate EP1 of the cell stack CS2 are arranged with a deviation in the stacking direction (X-axis direction). In the illustrated example, the end plate EP1 of the cell stack CS1 is arranged with a deviation toward the positive side of the X-axis relative to the end plate EP1 of the cell stack CS2.

[0065] With this configuration, the bolt BT1 that fixes the support base SS1 to the end plate EP1 and the bolt BT2 that fixes the support base SS2 to the end plate EP1 do not interfere with each other, thereby preventing an increase in the distance between the side-by-side arranged cell stacks CS1 and CS2. The end plates EP1 of the cell stacks CS1 and CS2 may be arranged without being shifted in the stacking direction.

[0066] <Arrangement relationship between end bus bar EB12 and end bus bar EB22 on the second end side> Next, the positional relationship between the end bus bar EB11 of the cell stack CS1 and the end bus bar EB21 of the cell stack CS2 on the second end side (X-axis positive direction side) will be described with reference to Fig. 7. Fig. 7 is a schematic side view showing the positional relationship between the end bus bar EB12 of the cell stack CS1 and the end bus bar EB22 of the cell stack CS2 on the second end side.

[0067] 7, the tip of the end bus bar EB22 is positioned below and shifted toward the second end (positive X-axis direction) relative to the tip of the end bus bar EB12. The tip of the end bus bar EB12 and the tip of the end bus bar EB22 are also positioned side by side in the stacking direction of the rectangular cells C1 to C6. Therefore, just like the first end side, the opposing end bus bars EB12 and EB22 do not interfere with each other on the second end side, and an increase in the gap between the juxtaposed cell stacks CS1 and CS2 can be suppressed.

[0068] As described above, the end plate EP1 of the cell stack CS1 is positioned offset in the positive direction of the X-axis relative to the end plate EP1 of the cell stack CS2. Therefore, the amount of offset in the X-axis direction of the tips of the end bus bars EB12 and EB22 shown in Fig. 7 is smaller than the amount of offset in the X-axis direction of the tips of the end bus bars EB11 and EB21 shown in Fig. 5.

[0069] Although the connection destinations of the tip ends of the end bus bars EB11 and EB21 shown in FIGS. 5 and 6 and the tip ends of the end bus bars EB12 and EB22 shown in FIG. 7 are not shown, they are not particularly limited. For example, the tips of the end bus bars EB11 and EB21 shown in Figures 5 and 6 may be connected to each other by another bus bar (not shown) or the like to connect the cell stacks CS1 and CS2 in series. In that case, the tips of the end bus bars EB12 and EB22 shown in Figure 7 are not connected to each other, but are connected to, for example, a power supply destination or another cell stack (not shown).

[0070] On the other hand, the tips of the end bus bars EB12 and EB22 shown in Fig. 7 may be connected to each other by another bus bar (not shown) or the like to connect the cell stacks CS1 and CS2 in series. In this case, the tips of the end bus bars EB11 and EB21 shown in Fig. 5 and Fig. 6 are not connected to each other, but are connected to, for example, a power supply destination or another cell stack (not shown).

[0071] As described above, in the battery according to this embodiment, the tip of the end bus bar EB21 is arranged below and shifted toward the first end (negative X-axis direction) relative to the tip of the end bus bar EB11, as shown in Fig. 5. Also, as shown in Fig. 6, the tip of the end bus bar EB11 and the tip of the end bus bar EB21 are arranged side by side in the stacking direction of the rectangular cells C1 to C6. Therefore, the opposing end bus bars EB11 and EB21 do not interfere with each other, and an increase in the gap between the juxtaposed cell stacks CS1 and CS2 can be suppressed.

[0072] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0073] B1~B5 bus bar BT1, BT2 bolts C1~C6 Prismatic cells CM1, CM2 connecting member CS1, CS2 cell stack EB11, EB12 End bus bar (first end bus bar) EB21, EB22 End bus bar (second end bus bar) EP1, EP2 end plates NT1~NT6 Negative terminal PT1~PT6 Positive terminal SS1, SS2 support stand ST1, ST2 studs WP1, WP2 welds

Claims

1. A battery including first and second rectangular parallelepiped cell stacks in which a plurality of rectangular cells having terminals on their longitudinal end faces are stacked, the first and second cell stacks are arranged side by side such that first and second ends in a stacking direction correspond to each other, a base portion of a first end bus bar is fixed to a terminal of a rectangular cell located closest to the first end in the first cell stack; a base portion of a second end bus bar is fixed to a terminal of a rectangular cell located closest to the first end in the second cell stack; a tip end portion of the second end bus bar is disposed below the tip end portion of the first end bus bar and shifted toward the first end, a tip end portion of the first end bus bar and a tip end portion of the second end bus bar are arranged side by side in a stacking direction of the plurality of rectangular cells; Battery.

2. a tip end portion of the first end bus bar is placed on a first support base fixed to the first end of the first cell stack, a tip end portion of the second end bus bar is placed on a second support base fixed to the first end of the second cell stack; 10. The battery of claim 1.

3. a threaded rod provided on the first support base is inserted into a through hole provided at a tip end of the first end bus bar, a threaded rod provided on the second support base is inserted into a through hole provided at a tip end of the second end bus bar; 3. The battery of claim 2.

4. the first support base is fixed to an end plate at the first end of the first cell stack, the second support base is fixed to an end plate at the first end of the second cell stack.

4. The battery according to claim 2 or 3.

5. the first support base is bolted to an end plate at the first end of the first cell stack, the second support base is bolted to an end plate at the first end of the second cell stack, an end plate at the first end of the first cell stack and an end plate at the first end of the second cell stack are arranged to be shifted in the stacking direction; 5. The battery of claim 4.

Images