Cell stack and manufacturing method thereof

Abstract

To provide a cell stack that can be manufactured at a lower cost and easily.SOLUTION: A cell stack is a rectangular parallelepiped cell stack in which multiple rectangular cells are stacked, and includes multiple inter-cell members inserted between adjacent rectangular cells. The multiple inter-cell members include: a first inter-cell member including a plate-like spacer that absorbs variations in thickness of the rectangular cells, and a second inter-cell member that does not include the plate-like spacer. The plate-like spacer is made of hard plastic and has a uniform thickness, and the first inter-cell member and the second inter-cell member are arranged at irregular intervals.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a cell stack and a manufacturing method thereof. [Background technology]

[0002] In conventional cell stacks, terminals are provided on the top surface of each stacked prismatic cell. In recent years, as disclosed in Patent Document 1, cell stacks 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 prismatic cells stacked in the cell stack have a predetermined dimensional tolerance of ±b with respect to the design thickness a. In other words, the thickness of the prismatic cells is a±b. To date, in order to accommodate variations in the thickness of the prismatic cells, the inventors have selectively inserted two types of plate-shaped spacers with different thicknesses made of an elastic material, such as an elastomer containing synthetic rubber, between all adjacent prismatic cells. However, there are problems in that the elastic material is expensive and the manufacturing process is complicated because two types of plate-shaped spacers with different thicknesses are used.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a cell stack that can be manufactured more cheaply and easily. [Means for solving the problem]

[0006] A cell stack according to one aspect of the present disclosure includes: A rectangular parallelepiped cell stack in which a plurality of rectangular cells are stacked, a plurality of inter-cell members inserted between adjacent rectangular cells; The plurality of inter-cell members include: a first inter-cell member including a plate-like spacer that absorbs variations in thickness of the rectangular cells; a second inter-cell member that does not include the plate-like spacer, The plate-like spacers are made of hard plastic and have the same thickness. The first inter-cell members and the second inter-cell members are irregularly arranged.

[0007] In the cell stack according to the present disclosure, the multiple inter-cell components inserted between adjacent prismatic cells include a first inter-cell component including a plate-shaped spacer that absorbs variations in the thickness of the prismatic cells, and a second inter-cell component that does not include the plate-shaped spacer. The plate-shaped spacers are made of hard plastic and have the same thickness, and the first inter-cell component and the second inter-cell component are arranged irregularly. In other words, by irregularly inserting a single type of plate-shaped spacer of the same thickness made of inexpensive hard plastic between adjacent prismatic cells, variations in the thickness of the prismatic cells are absorbed. This makes it possible to provide a cell stack that is cheaper and easier to manufacture.

[0008] The first and second inter-cell members may each include a heat insulating plate having the same thickness. With this configuration, all adjacent prismatic cells can be insulated from each other.

[0009] The thickness of the plurality of plate-like spacers may be equal to the dimensional tolerance of the thickness of the prismatic cells. With this configuration, variations in the thickness of the prismatic cells can be easily absorbed simply by inserting or not inserting the plate-like spacers.

[0010] A method for manufacturing a cell stack according to one aspect of the present disclosure includes: A cell stack manufacturing method for manufacturing a rectangular parallelepiped cell stack by sequentially stacking prismatic cells and inter-cell members, comprising: Each time prismatic cells are stacked, the thickness of the cells is measured. determining whether or not the total thickness, which is the sum of the thickness of the prismatic cells and inter-cell members already stacked and the measured thickness of the prismatic cells to be stacked, exceeds a predetermined reference value; If the total thickness does not exceed the predetermined reference value, a first inter-cell member including a plate-like spacer that absorbs thickness variations of the prismatic cells is inserted as the inter-cell member, and the prismatic cells are stacked; If the total thickness exceeds the predetermined reference value, a second inter-cell member that does not include the plate-like spacer is inserted as the inter-cell member, and the prismatic cells are stacked; The plate-like spacers are made of hard plastic and have the same thickness.

[0011] In the cell stack manufacturing method according to the present disclosure, the thickness of each prismatic cell to be stacked is measured each time prismatic cells are stacked, and a determination is made as to whether the total thickness, calculated by adding the thickness of the prismatic cells and plate-like spacers already stacked to the measured thickness of the prismatic cells to be stacked, exceeds a predetermined reference value. If the total thickness does not exceed the predetermined reference value, the prismatic cells to be stacked are stacked with the plate-like spacers inserted. If the total thickness exceeds the predetermined reference value, the prismatic cells to be stacked are stacked without the plate-like spacers inserted. Here, the plate-like spacers are made of hard plastic and have the same thickness. In other words, by inserting or not inserting a single type of plate-like spacer made of inexpensive hard plastic between adjacent prismatic cells, variations in the thickness of the prismatic cells are compensated for. This allows for the provision of a cell stack that is cheaper and easier to manufacture. [Effects of the Invention]

[0012] The present disclosure makes it possible to provide a cell stack that can be manufactured more cheaply and easily. [Brief explanation of the drawings]

[0013] [Figure 1]FIG. 1 is a perspective view showing a cell stack according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a cell stack according to a first embodiment. [Figure 3] FIG. 2 is a side view showing the cell stack according to the first embodiment. [Figure 4] 4 is a flowchart showing a method for manufacturing a cell stack according to the first embodiment. 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) <Cell stack configuration> First, the configuration of the cell stack according to the first embodiment will be described with reference to Figures 1 to 3. Figures 1 and 2 are both perspective views showing the cell stack according to the first embodiment. Figure 3 is a side view showing the cell stack according to the first embodiment.

[0016] Naturally, the right-handed XYZ Cartesian coordinate system shown in Figures 1 to 3 is for the sake of convenience in explaining the positional relationships of the components. In Figures 1 to 3, the positive direction of the Z axis is normally vertically upward, and the XY plane is the horizontal plane, which is common among the drawings.

[0017] 1 and 2, the cell stack CS according to this embodiment includes rectangular cells C1 to C6 and bus bars B1 to B5. Furthermore, as shown in Fig. 3, the cell stack CS according to this embodiment includes inter-cell members IC1 to IC5, end plates EP1 and EP2, and elastic members EM1 and EM2.

[0018] Note that Fig. 2 does not include inter-cell members IC1 to IC5, end plates EP1 and EP2, and elastic members EM1 and EM2 shown in Fig. 3. Fig. 3 also shows a state before the bus bars B1 to B5 shown in Figs. 1 and 2 are installed.

[0019] The cell stack CS according to this embodiment is used, for example, in an in-vehicle battery. The vehicle in which the cell stack CS according to this 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 cell stack CS.

[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 a cell stack CS. The prismatic cells C1 to C6 are secondary batteries such as lithium-ion batteries or nickel-metal hydride batteries.

[0021] Note that the cell stack CS is shown in a simplified form in Figures 1 and 2. The cell stack CS shown in Figures 1 and 2 is composed of six prismatic cells C1 to C6, but the number of prismatic cells that compose the cell stack CS is not particularly limited. Usually, the cell stack CS is composed of a larger number of prismatic cells.

[0022] As shown in Fig. 1, a positive electrode terminal PT1 is provided on one longitudinal end face (the end face on the negative Y-axis direction) of the prismatic cell C1. Although not particularly limited, the positive electrode terminal PT1 shown in Fig. 1 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 direction) 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] 1, 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.

[0026] On the other hand, as shown in Fig. 2, 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.

[0027] 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.

[0028] 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.

[0029] 2, 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 CS shown in FIGS. 1 and 2, the prismatic cells C1 to C6 are connected in series by the bus bars B1 to B5.

[0030] The negative electrode terminal NT1 of the prismatic cell C1 shown in Fig. 2 is connected to the positive electrode terminal of another cell stack via, for example, a bus bar (not shown), although this is not a limitation. The positive electrode terminal PT6 of the prismatic cell C6 shown in Fig. 2 is connected to the negative electrode terminal of yet another cell stack via, for example, a bus bar (not shown). This configuration allows, for example, multiple cell stacks to be connected in series.

[0031] The bus bars B1 to B5 shown in FIGS. 1 and 2 have the same configuration, so only the bus bar B1 will be described. 1, the busbar B1 is a plate-shaped member that electrically connects the positive electrode terminal PT1 of the adjacent prismatic cell C1 and the negative electrode terminal NT2 of the adjacent prismatic cell C2. The busbar B1 is made of a metal material such as copper, which has excellent electrical conductivity.

[0032] 1, the busbar B1 is, for example, a plate-like member having a rectangular shape when viewed in the XZ plane. The busbar B1 is provided so as to cover substantially the entire positive electrode terminal PT1 of the prismatic cell C1 and the negative electrode terminal NT2 of the prismatic cell C2. The busbar B1 has a pair of welds WP1 and WP2 welded to the positive electrode terminal PT1 of the prismatic cell C1 and the negative electrode terminal NT2 of the prismatic cell C2, respectively, which are arranged adjacent to each other.

[0033] Although not particularly limited, the welded portions WP1 and WP2 shown in FIG. 1 are provided on both ends in the X-axis direction on the lower side (negative Z-axis side) of the bus bar B1. Here, FIG. 1 shows the welded portions WP1 and WP2 before welding. The welded portions WP1 and WP2 shown in FIG. 1 are countersunk and have a thinner plate thickness than other regions. Furthermore, the welded portions WP1 and WP2 shown in FIG. 1 have a circular shape when viewed in the XZ plane and have a through hole in the center.

[0034] The welding method is not particularly limited, but for example, by irradiating a laser beam onto welded portion WP1 from the negative Y-axis direction side, the bus bar B1 is welded to the positive electrode terminal PT1 of prismatic cell C1 at welded portion WP1. Similarly, by irradiating a laser beam onto welded portion WP2 from the negative Y-axis direction side, the bus bar B1 is welded to the negative electrode terminal NT2 of prismatic cell C2 at welded portion WP2.

[0035] As shown in Fig. 3, inter-cell members IC1 to IC5 are plate-like members inserted between adjacent prismatic cells C1 to C6. As shown in Fig. 3, for example, inter-cell member IC1 is inserted between adjacent prismatic cells C1 and C2. Inter-cell member IC1 insulates adjacent prismatic cells C1 and C2 from each other and adjusts the distance between adjacent prismatic cells C1 and C2.

[0036] More specifically, each of the inter-cell components IC1 to IC5 is either a first inter-cell component including a plate-like spacer that absorbs variations in the thickness of the prismatic cells C1 to C6, or a second inter-cell component that does not include a plate-like spacer. Here, the plate-like spacers are made of hard plastic and have the same thickness.

[0037] The prismatic cells C1 to C6 have a predetermined dimensional tolerance of ±b with respect to the designed thickness a. That is, the thickness of the prismatic cells C1 to C6 is a±b. Each of the inter-cell members IC1 to IC5 (that is, the first inter-cell member and the second inter-cell member) may include a heat insulating plate having the same thickness.

[0038] Whether the first inter-cell components or the second inter-cell components are used for the inter-cell components IC1 to IC5 is determined when the cell stack CS is manufactured. When stacking the prismatic cells C1 to C6 in order, the thickness of the prismatic cell to be stacked is measured each time a prismatic cell is stacked, and it is determined whether the total thickness, obtained by adding the thickness of the prismatic cell and inter-cell components already stacked to the measured thickness of the prismatic cell to be stacked, exceeds a predetermined reference value.

[0039] For example, when stacking prismatic cell C3, it is determined whether the total thickness, calculated by adding the measured thickness of prismatic cell C3 to the thicknesses of the already stacked prismatic cells C1, C2, and inter-cell component IC1, exceeds a predetermined reference value. The reference value for the total thickness is determined in advance for each of the prismatic cells C2 to C6 to be stacked second or later. For example, the reference value is determined appropriately based on the designed thickness a of the prismatic cells, the dimensional tolerance ±b, the designed thickness of the heat insulating boards, etc.

[0040] If the total thickness does not exceed the reference value, a first inter-cell component including a plate-like spacer is inserted as the inter-cell component IC2, and prismatic cell C3 is stacked. On the other hand, if the total thickness exceeds the reference value, a second inter-cell component not including a plate-like spacer is inserted as the inter-cell component IC2, and prismatic cell C3 is stacked. The same applies when stacking the other prismatic cells C2, C4 to C6.

[0041] As a result, in the cell stack CS according to this embodiment, first inter-cell components including plate-shaped spacers and second inter-cell components not including plate-shaped spacers are irregularly arranged as inter-cell components IC1 to IC5.

[0042] Here, by appropriately setting the reference value for the total thickness and making the thickness of the plate-like spacer equal to the dimensional tolerance width 2b of the prismatic cells, the deviation of the center positions of the prismatic cells C1 to C6 shown in Figure 3 from the target position can be made equal to or less than the absolute value b of the dimensional tolerance ±b. Also, the length of the prismatic cells C1 to C6 stacked via the inter-cell components IC1 to IC5 can be made closer to the target value.

[0043] As shown in Fig. 3, end plate EP1 is arranged via elastic member EM1 at the end of the stacked prismatic cells C1 to C6 on the negative X-axis direction side, with inter-cell members IC1 to IC5 sandwiched between them. End plate EP2 is arranged via elastic member EM2 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.

[0044] The elastic members EM1 and EM2 are plate-like members made of an elastic material such as elastomer containing synthetic rubber. 3, the length L of the cell stack CS is the distance between the inner surfaces of the end plates EP1 and EP2, and is a fixed value. Any deviation from the target length of the prismatic cells C1 to C6 stacked via inter-cell members IC1 to IC5 can be absorbed by the elastic members EM1 and EM2.

[0045] As explained above, in the cell stack CS according to this embodiment, one type of plate-shaped spacer of the same thickness made of inexpensive hard plastic is inserted irregularly between adjacent prismatic cells C1 to C6 to absorb variations in the thickness of the prismatic cells C1 to C6. Therefore, the cell stack CS according to this embodiment can be manufactured more cheaply and easily than a cell stack in which two types of plate-shaped spacers made of elastic material but with different thicknesses are selectively inserted between all adjacent prismatic cells.

[0046] <Cell stack manufacturing method> Next, a method for manufacturing a cell stack according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the method for manufacturing a cell stack according to the first embodiment. Specifically, a rectangular parallelepiped cell stack CS is manufactured by sequentially stacking prismatic cells C1 to C6 and inter-cell members IC1 to IC5 shown in Fig. 3.

[0047] First, as shown in Fig. 4, the thickness of the prismatic cells to be stacked is measured (step ST1). Specifically, the thickness of the prismatic cell C1 to be stacked is measured. Next, as shown in FIG. 4, if it is the first prismatic cell, the process returns to step ST1 as an exception. If it is not the first prismatic cell, the total thickness is calculated by adding the thickness of the measured prismatic cell to the thicknesses of the prismatic cells and inter-cell components already stacked (step ST2).

[0048] Specifically, after measuring the thickness of the first prismatic cell C1, the process returns to step ST1 to measure the thickness of prismatic cell C2, and then proceeds to step ST2, where the total thickness is calculated by adding the measured thickness of prismatic cell C2 to the thickness of the prismatic cells C1 already stacked.

[0049] Next, as shown in FIG. 4, it is determined whether the total thickness exceeds a predetermined reference value (step ST3). If the total thickness does not exceed the predetermined reference value (NO in step ST3), first inter-cell components including plate-like spacers that absorb variations in the thickness of the prismatic cells are inserted as inter-cell components, and the prismatic cells are stacked (step ST4). Specifically, first inter-cell components including plate-like spacers are inserted as inter-cell components IC1, and the prismatic cells C2 are stacked. Here, the plate-like spacers are made of hard plastic and have the same thickness.

[0050] On the other hand, if the total thickness exceeds the predetermined reference value (YES in step ST3), a second inter-cell component that does not include a plate-like spacer is inserted as the inter-cell component, and the prismatic cells are stacked (step ST5). Specifically, a second inter-cell component that does not include a plate-like spacer is inserted as the inter-cell component IC1, and the prismatic cells C2 are stacked.

[0051] As shown in Fig. 4, after stacking the prismatic cells in step ST4 or step ST5, if the stacked prismatic cell is not the last prismatic cell, the process returns to step ST1. On the other hand, if the stacked prismatic cell is the last prismatic cell, the process ends. Specifically, since the stacked prismatic cell C2 is not the last prismatic cell, the process returns to step ST1 and measures the thickness of the prismatic cell C3 to be stacked.

[0052] Next, the process proceeds to step ST2 as shown in Fig. 4. Specifically, the total thickness is calculated by adding the measured thickness of the prismatic cell C3 to the thicknesses of the prismatic cells C1, C2 and the inter-cell component IC1 that have already been stacked.

[0053] Next, as shown in FIG. 4, if the total thickness does not exceed a predetermined reference value (NO in step ST3), the process proceeds to step ST4. Specifically, a first inter-cell component including a plate-like spacer is inserted as the inter-cell component IC2, and prismatic cells C3 are stacked. On the other hand, if the total thickness exceeds the predetermined reference value (YES in step ST3), the process proceeds to step ST5. Specifically, a second inter-cell component not including a plate-like spacer is inserted as the inter-cell component IC2, and prismatic cells C3 are stacked.

[0054] Then, as shown in FIG. 4, after stacking the prismatic cells C3 in step ST4 or step ST5, the process returns to step ST1 and the thickness of the prismatic cells C4 to be stacked is measured. In this way, steps ST1 to ST5 described above are repeated up to the last prismatic cell C6, thereby sequentially stacking the prismatic cells C1 to C6 and the inter-cell members IC1 to IC5 to manufacture the cell stack CS.

[0055] As described above, the stack manufacturing method according to this embodiment absorbs variations in the thickness of the prismatic cells by inserting or not inserting one type of plate-shaped spacer made of inexpensive hard plastic and having the same thickness between adjacent prismatic cells. Therefore, the stack manufacturing method according to this embodiment can manufacture a cell stack more cheaply and easily than a method in which two types of plate-shaped spacers made of elastic material but with different thicknesses are selectively inserted between all adjacent prismatic cells.

[0056] 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]

[0057] B1~B5 bus bar C1~C6 Prismatic cells CS Cell Stack EM1, EM2 elastic members EP1, EP2 end plates IC1~IC5 Inter-cell components NT1~NT6 Negative terminal PT1~PT6 Positive terminal WP1, WP2 welds

Claims

1. A rectangular parallelepiped cell stack in which a plurality of rectangular cells are stacked, a plurality of inter-cell members inserted between adjacent rectangular cells; The plurality of inter-cell members include: a first inter-cell member including a plate-like spacer that absorbs variations in thickness of the rectangular cells; a second inter-cell member that does not include the plate-like spacer, The plate-like spacers are made of hard plastic and have the same thickness. the first inter-cell members and the second inter-cell members are irregularly arranged; Cell stack.

2. each of the first and second inter-cell members includes an insulating board having the same thickness; The cell stack according to claim 1 .

3. The thickness of the plate-like spacer is equal to the dimensional tolerance width of the thickness of the rectangular cell. The cell stack according to claim 1 or 2.

4. A cell stack manufacturing method for manufacturing a rectangular parallelepiped cell stack by sequentially stacking prismatic cells and inter-cell members, comprising: Each time prismatic cells are stacked, the thickness of the cells is measured. determining whether or not the total thickness, which is the sum of the thickness of the prismatic cells and inter-cell members already stacked and the measured thickness of the prismatic cells to be stacked, exceeds a predetermined reference value; If the total thickness does not exceed the predetermined reference value, a first inter-cell member including a plate-like spacer that absorbs thickness variations of the prismatic cells is inserted as the inter-cell member, and the prismatic cells are stacked; If the total thickness exceeds the predetermined reference value, a second inter-cell member that does not include the plate-like spacer is inserted as the inter-cell member, and the prismatic cells are stacked; The plate-like spacers are made of hard plastic and have the same thickness. A method for manufacturing a cell stack.

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