Battery pack

Abstract

The present invention is provided with: a plurality of battery modules (210) in which a plurality of plate-shaped battery cells are stacked in the thickness direction of the battery cells, the battery modules (210) being provided in a direction intersecting the thickness direction of the battery cells; and an aggregate terminal (410) that is an end point of an electrical path in which the plurality of battery modules (210) are electrically connected in series. The aggregate terminal (410) extends in a direction along the thickness direction of the battery cells, and the tip of the aggregate terminal (410) protrudes further than the battery modules (210) in the thickness direction of the battery cells. By setting the position of the tip and the orientation of the aggregate terminal (410) in this way, an electrical device connected to the aggregate terminal (410) can be easily disposed relative to the battery pack (400) in the thickness direction of the battery cells.

Description

Battery Pack Cross - reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2024 - 161328 filed in Japan on September 18, 2024, and the content of the base application is incorporated herein by reference in its entirety.

[0002] Regarding a battery pack, particularly regarding terminals for electrically connecting the battery pack to an external device.

[0003] Patent Document 1 discloses a battery pack. A battery pack requires terminals for electrically connecting to an external device. Patent Document 1 does not disclose where to provide the terminals. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.

[0004] Japanese Patent No. 6750117

[0005] Consider a case where a battery pack includes a plurality of battery cells and the plurality of battery cells are connected in series. In this case, the terminal at the end of the electrical path is defined as the main terminal. Electrical devices such as a relay for connecting the battery pack and an external component such as an inverter, or a control circuit for detecting the state of the battery cell and performing charge - discharge control are connected to the main terminal. If the overall length of the battery cells in the thickness direction of the battery pack, including the electrical devices connected to the main terminal, is long, installation may be difficult depending on the installation location.

[0006] The present disclosure has been made based on this situation, and its object is to provide a battery pack capable of suppressing the overall length of the battery cells in the thickness direction from becoming too long when electrical devices connected to the main terminal are added to the battery pack.

[0007] The above object is achieved by the combination of features described in the independent claims, and the dependent claims define further advantageous specific examples. The reference signs in parentheses described in the claims indicate the correspondence relationship with the specific aspects described in the embodiments described later as one aspect, and do not limit the disclosed technical scope.

[0008] One disclosure for achieving the above objective is a battery pack comprising multiple battery modules, each in which multiple plate-shaped battery cells are stacked in the thickness direction of the battery cells, arranged in a direction intersecting the thickness direction of the battery cells, and comprising a total terminal which is the end of an electrical path in which the multiple battery modules are electrically connected in series, wherein the total terminal extends in a direction along the thickness direction of the battery cells, and its tip protrudes beyond the battery module in the thickness direction of the battery cells.

[0009] The terminals on the battery pack extend in the direction of the battery cell's thickness, with their tips protruding beyond the battery module in the same direction. This orientation and positioning of the terminals makes it easier to position electrical devices connected to the terminals in the direction of the battery cell's thickness relative to the battery pack.

[0010] The battery pack comprises multiple battery modules, each consisting of multiple plate-shaped battery cells stacked in the thickness direction of the battery cells, arranged in a direction intersecting the thickness direction of the battery cells. This prevents the battery pack from becoming excessively long in the thickness direction of the battery cells. For example, if multiple battery modules are arranged horizontally, the height of the battery pack can be prevented from becoming excessively long.

[0011] Based on the above, this battery pack makes it easy to position electrical devices connected to the total terminals in the thickness direction of the battery cells relative to the battery pack, and even when such electrical devices are positioned in the thickness direction of the battery cells relative to the battery pack, it is possible to prevent the overall length of the battery pack in the thickness direction of the battery cells, including the electrical devices connected to the total terminals, from becoming too long.

[0012] External perspective view of the battery pack of the first embodiment. Enlarged view of area II in Figure 1. Exploded perspective view of the battery pack. Diagram illustrating the configuration of the battery housing. Diagram showing the state in which the battery modules are housed in the battery housing. Partial enlarged view of Figure 5. Cross-sectional view along line VII-VII in Figure 6. Cross-sectional view along line VIII-VIII in Figure 6. End view of the core material of the second embodiment. Perspective view of the core material of the second embodiment. Cross-sectional view along line XI-XI in Figure 10. Perspective view of the short side wall of the second embodiment. External perspective view of the battery pack of the third embodiment. Diagram illustrating the long side wall and short side wall of the battery pack of the third embodiment. Cross-sectional view along line XV-XV in Figure 13. Cross-sectional view along line XVI-XVI in Figure 13. Side view of the battery pack of the fourth embodiment. Partial enlarged view of Figure 17. Side view of the battery pack of the fifth embodiment. Diagram showing an example of battery module arrangement. Diagram showing the state in which the BBM case is sealed.

[0013] The embodiments will now be described based on the drawings. Figure 1 is an external perspective view of the battery pack 100 of the first embodiment. The battery pack 100 is used, for example, mounted in a vehicle. As shown in Figure 1, the battery pack 100 comprises a battery pack cover 110, a long side wall 120, and a short side wall 130 as its exterior. The base member 140 shown in Figure 3 is also an exterior of the battery pack 100. Furthermore, this battery pack 100 also includes an equipment case 150.

[0014] The battery pack 100 has a flattened shape overall. The battery pack 100 can be installed with the battery pack cover 110 facing upwards and the base member 140 facing downwards.

[0015] This is a roughly rectangular, flat component of the battery pack cover 110. The material of the battery pack cover 110 can be a metal such as an aluminum alloy. The battery pack cover 110 has multiple concave outer surfaces 112 formed on its outer surface 111, which is exposed to the outside when the battery pack 100 is assembled. Note that in Figure 1, only one concave outer surface 112 is labeled with a reference numeral. In other cases, if there are multiple identical elements, only some of the elements may be labeled with a reference numeral. The multiple concave outer surfaces 112 are all the same shape. The concave outer surfaces 112 are recessed portions of the outer surface 111 that are flatter than the outer planar surface 113.

[0016] In this battery pack 100, twelve concave outer surfaces 112 are formed in a straight line parallel to the long side of the outer surface 111 of the battery pack cover 110, and four concave outer surfaces 112 are formed in a straight line parallel to the short side of the outer surface 111 of the battery pack cover 110. The number and size of the concave outer surfaces 112 can be changed in various ways.

[0017] The long side wall 120 and the short side wall 130 form the side walls of the battery pack 100. The long side wall 120 and the short side wall 130 are rectangular plate shapes. The long side wall 120 forms the long side surface of the battery pack 100, and the short side wall 130 forms the short side surface of the battery pack 100. Metals such as aluminum alloy can be used for these long side wall 120 and short side wall 130.

[0018] The equipment case 150 houses electrical equipment such as relays that connect the battery pack 100 to external components such as inverters, or control circuits that detect the state of the battery cells 230 (see Figure 7) and perform charge and discharge control.

[0019] Figure 2 shows an enlarged view of area II in Figure 1. As shown in Figure 2, the inlet end 161 and outlet end 162 of the refrigerant piping protrude perpendicularly from the short side wall 130. The refrigerant piping extends from the inlet end 161 parallel to the long side of the outer surface 111 of the battery pack cover 110, and folds back near the short side wall 130 on the side opposite to the inlet end 161. The refrigerant piping then extends from the folded portion to the outlet end 162 parallel to the long side of the outer surface 111 of the battery pack cover 110. Refrigerant flows through the refrigerant piping. The refrigerant cools the battery cells 230. Liquid refrigerant can be used as the refrigerant. An example of a liquid refrigerant is water.

[0020] Figure 3 is an exploded perspective view of the battery pack 100. Note that Figure 3 shows the battery pack 100 with some of its components removed. As shown in Figure 3, the battery pack 100 includes a battery module assembly 170. The battery module assembly 170 is sandwiched between a battery pack cover 110 and a base member 140.

[0021] The base member 140 has a rectangular flat plate shape. The base member 140 can also be made of a metal such as an aluminum alloy. Multiple inwardly convex portions 142 are formed on the inner surface 141 of the base member 140, which is the surface facing the battery module assembly 170. The inwardly convex portions 142 are parts that protrude in a convex shape from the inner surface portion 143, which is flat on the inner surface 141. The inwardly convex portions 142 are formed in a position that faces the outer concave portion 112 of the battery pack cover 110, sandwiching the battery module assembly 170 when the battery pack 100 is assembled.

[0022] The battery pack cover 110 and the base member 140 have a common shape. The outer concave portion 112 of the battery pack cover 110 forms a convex portion on the surface of the battery pack cover 110 that faces the battery module assembly 170. This convex portion has the same shape as the inner convex portion 142 of the base member 140.

[0023] The battery module assembly 170 comprises a battery housing 180, a battery pack housing 200, and a battery module 210. A short side wall 130 can also be an element of the battery module assembly 170.

[0024] The configuration of the battery housing 180 will be explained using Figure 4. The battery housing 180 has a configuration in which multiple frame members 190 are fixed to a single core material 181. The materials for these core material 181 and frame members 190 can also be metals such as aluminum alloy. As shown in Figure 3, the battery pack 100 has two battery housings 180.

[0025] The core material 181 is straight. The frame members 190 are also straight, and each frame member 190 extends perpendicularly from the core material 181. The frame members 190 are fixed at equal intervals along the core material 181 from one end, and frame members 190 are also fixed to the other end of the core material 181.

[0026] Furthermore, with respect to one frame member 190, another frame member 190 is positioned symmetrically across the core material 181. Each frame member 190 comprises a main frame portion 191 and a restricting portion 192. The main frame portion 191 has a longitudinal flat plate shape. The main frame portion 191 also has a longitudinal rectangular shape. A pair of restricting portions 192 are provided on either side of the main frame portion 191.

[0027] Figure 5 shows the state in which the battery module 210 is housed in the battery housing 180. The battery module 210 is rectangular in shape, with its side facing the frame member 190. One end face of the battery module 210 faces the core material 181, and the other end face has cell terminals 231, which are the terminals of the battery cells 230.

[0028] Figure 6 is a magnified view of a portion of Figure 5. Unlike Figure 5, Figure 6 shows the battery busbar module case (hereinafter referred to as the BBM case) 220 installed. The BBM case 220 covers the end face of the battery module 210 on the cell terminal 231 side, while exposing the cell terminals 231.

[0029] A Flexible Printed Circuit (FPC) 221 is provided on the outside of the BBM case 220. Multiple voltage detection lines are formed on the FPC 221. The voltage detection lines are connected to the cell terminals 231. A voltage detection circuit is installed in the equipment case 150, and the FPC 221 is connected to the voltage detection circuit.

[0030] Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6. The battery module 210 comprises a plurality of battery cells 230. In this embodiment, one battery module 210 comprises four battery cells 230. The battery cells 230 are flat, and the shape of the battery cell 230 when viewed from the thickness direction is rectangular. The four battery cells 230 are stacked in the thickness direction. In the battery cell 230, the surface on which other battery cells 230 are stacked is the stacking surface, the surface facing the main frame portion 191 of the frame member 190 is the side surface, and the surface on which the cell terminals 231 are provided and the surface facing the core material 181 are the end faces.

[0031] A battery cell 230 refers to a single battery, and the type of battery is a rechargeable battery. Various types of rechargeable batteries can be used as battery cells 230. For example, lithium-ion rechargeable batteries and nickel-metal hydride rechargeable batteries can be used as battery cells 230.

[0032] As can be seen from Figures 6 and 7, the frame member 190 is positioned relative to the battery module 210 in the lateral direction of the battery cells 230. The restricting portion 192 of the frame member 190 is flat and extends from the longitudinal side of the main frame portion 191 in a direction perpendicular to the main frame portion 191, with the same length in both directions. Due to this configuration, the cross-sectional shape of the frame member 190, as shown in Figure 7, is the letter H. The size of the inward convex portion 142 of the base member 140 is such that it can press against the stacked surface of the battery cells 230 that are exposed between a pair of frame members 190 that house one battery module 210.

[0033] The main frame portion 191 of the frame member 190 faces the side surface of the battery module 210. A gap exists between the main frame portion 191 and the side surface of the battery module 210. In other words, the battery module 210 is not clamped from the side by the frame member 190. A pair of restricting portions 192 on the frame member 190 face the battery module 210 on both sides in the thickness direction of the battery module 210. The distance between the pair of restricting portions 192 is slightly greater than the thickness direction length of the battery module 210. Therefore, the restricting portions 192 restrict the movement of the battery cells 230 in the thickness direction of the battery module 210. Note that the restriction may be such that the battery module 210 prohibits the movement of the battery cells 230 in the thickness direction. However, the regulations may allow the battery module 210 to move slightly in the thickness direction of the battery cell 230, as long as the movement of the battery cell 230 in the thickness direction does not cause the battery module 210 to detach from the frame member 190.

[0034] There are several methods for assembling the battery module 210 so that it is housed in the frame members 190. In one method, four battery cells 230 are stacked on top of each other, and the four battery cells 230 are moved together in a direction parallel to the frame members 190, and then inserted into a pair of frame members 190. In another method, the battery cells 230 are moved one by one in a direction parallel to the frame members 190, and then inserted one by one between a pair of frame members 190. In either method, when inserting the battery cells 230 between a pair of frame members 190, the direction of movement of the battery cells 230 is guided by the frame members 190.

[0035] The cell terminals 231 include a negative cell terminal 231m, which is a negative terminal, and a positive cell terminal 231p, which is a positive terminal. When the negative and positive terminals are not distinguished, they are referred to simply as cell terminals 231. As shown in Figure 6, the negative cell terminal 231m of one battery cell 230 and the positive cell terminal 231p of another battery cell 230 stacked on that battery cell 230 are electrically connected. In addition, the cell terminals 231 of a battery cell 230 at the end of the stacking direction in one battery module 210 and the cell terminals 231 of a battery cell 230 at the end of the stacking direction in an adjacent battery module 210 are electrically connected by a busbar 240. In this way, the multiple battery cells 230 provided in the battery pack 100 are connected in series.

[0036] Figure 8 is a cross-sectional view of the battery pack 100 taken along the line VIII-VIII in Figure 6. Although the battery pack cover 110, base member 140, battery pack housing 200, etc., are not shown in Figure 6, since Figure 8 is a cross-sectional view of the battery pack 100, the battery pack cover 110, base member 140, and battery pack housing 200 are also shown in Figure 8. Furthermore, as shown in Figure 8, the battery pack 100 is equipped with a cooler 250. The battery pack housing 200 and cooler 250 are made of metal such as aluminum alloy.

[0037] The cell terminal 231 is a conductive metal plate that protrudes from the end face of the battery cell 230, and its base extends in a direction perpendicular to the thickness direction of the battery cell 230. The tip of the cell terminal 231 is curved in the thickness direction of the battery cell 230. The battery cells 230 in the battery module 210 are connected in series by the tip of the cell terminal 231 extending in the thickness direction of the battery cell 230 contacting the tip of the cell terminal 231 of an adjacent battery cell 230 in the stacking direction.

[0038] The BBM case 220 is made of resin. As shown in Figure 8, the portion of the BBM case 220 facing the end face of the battery cell 230 is in contact with the end face of the battery cell 230, and the end face of the battery cell 230 and the BBM case 220 form a space for housing the cell terminals 231.

[0039] A cushioning material 260 is provided between the battery module 210 and the outer concave portion 112 of the battery pack cover 110. The cushioning material 260 is, for example, ethylene propylene rubber. In the first embodiment, the battery pack cover 110 and the base member 140 press against the battery cell 230 via the cushioning material 260.

[0040] As shown in Figure 8, the battery pack housing 200 comprises a cover-side flat plate portion 201 that contacts the battery pack cover 110, a base-side flat plate portion 202 that contacts the base member 140, and a side plate portion 203 that is connected to the cover-side flat plate portion 201 and the base-side flat plate portion 202 and perpendicular to them. The side plate portion 203 is flat in shape.

[0041] As shown in Figure 3, the battery pack housing 200 is the same length as the core material 181 of the battery housing 180. Together with the core material 181, the battery pack cover 110, and the base member 140, the battery pack housing 200 forms a housing chamber for housing the battery cells 230. The side plate portion 203 of the battery pack housing 200 is the wall of the housing chamber, i.e., the housing chamber wall portion. The cell terminal 231 side of the battery cells 230 is sealed by the battery pack housing 200, the battery pack cover 110, and the base member 140.

[0042] An insulating heat dissipation member 270 is in contact with the inner surface of the side plate portion 203. For the heat dissipation member 270, a resin sheet having insulation, heat conductivity, and flexibility can be used. The cell terminal 231 is disposed on the inner wall side of the side plate portion 203, and the tip of the cell terminal 231 is in contact with the heat dissipation member 270. The BBM case 220 is also in contact with the heat dissipation member 270. The cell terminal 231 and the BBM case 220 are in contact with the side plate portion 203 via the heat dissipation member 270.

[0043] A cooler 250 is fixed to the outer wall, that is, the outer surface of the side plate portion 203. The cooler 250 includes a flat cooler flat portion 251 and a cooler convex portion 252. The cooler convex portion 252 is a plate-like body including two convex portions protruding in a direction away from the cooler flat portion 251.

[0044] By being surrounded by the cooler flat portion 251 and the cooler convex portion 252, two refrigerant flow paths 253 are formed. One refrigerant flow path 253 is connected to the inlet side end portion 161, and the other refrigerant flow path 253 is connected to the outlet side end portion 162. The two refrigerant flow paths 253 extend along the longitudinal direction of the cooler flat portion 251 and are connected near the short side wall 130 on the side where the inlet side end portion 161 and the outlet side end portion 162 are not provided.

[0045] As described above, the battery pack 100 of the first embodiment includes a battery module 210, and the battery module 210 is accommodated in the frame member 190 in a direction facing the side surface direction of the battery cell 230. Since the battery module 210 is not sandwiched by the frame member 190, the battery module 210 can be easily accommodated in the space formed by the frame member 190. Therefore, the work of assembling the battery pack 100 becomes easy.

[0046] Further, the frame member 190 includes a regulating portion 192 that regulates the movement of the battery module 210 in the thickness direction of the battery cell 230. Therefore, when an external force is applied to the battery pack 100, it is possible to suppress the battery module 210 from moving in the thickness direction of the battery cell 230 and easily falling off from the battery pack 100, and there is no need to improve the rigidity of the battery pack cover 110 more than necessary. Therefore, the battery pack 100 can be miniaturized.

[0047] Further, the frame member 190 includes a main frame portion 191. Since the main frame portion 191 faces the side surfaces of the battery module 210 and the battery cell 230, when the battery module 210 or the battery cell 230 is inserted between the pair of frame members 190, it is possible to prevent the battery module 210 or the battery cell 230 from shifting in a direction orthogonal to the main frame portion 191. Also in this regard, the assembly work of the battery pack 100 becomes easier.

[0048] The battery pack 100 includes a plurality of battery modules 210, and each battery module 210 is accommodated between a pair of frame members 190. Since all the frame members 190 are fixed to the linear core material 181, all the frame members 190 are arranged on the same plane. Therefore, all the battery modules 210 are also arranged on the same plane. Thus, the battery pack 100 can be made into a shape close to flat.

[0049] Further, since the core material 181 to which the plurality of frame members 190 are fixed is linear, the directions in which the battery module 210 or the battery cell 230 is inserted between the pair of frame members 190 can all be the same. This also makes the assembly work of the battery pack 100 easier.

[0050] The frame member 190 has an H-shaped cross-section, and restricting portions 192 are connected to two longitudinal sides of the main frame portion 191, respectively. In addition, each restricting portion 192 extends from the main frame portion 191 in both directions in a direction orthogonal to the main frame portion 191. Such a configuration of the frame member 190 is easy to manufacture, and the movement of four battery cells 230 can be restricted by one frame member 190.

[0051] The battery housing section 180 includes a core material 181 to which multiple frame members 190 are connected. This core material 181 faces the end faces of multiple battery modules 210. Therefore, one battery housing section 180 can accommodate multiple battery modules 210, and the core material 181 can restrict the movement of the multiple battery modules 210 in a direction perpendicular to the end faces of the battery modules 210.

[0052] The battery pack 100 includes a battery pack housing 200. This battery pack housing 200 includes side plate portions 203 that form the walls of the housing chamber in which the battery cells 230 are housed. A cooler 250 is in contact with the outer surface of this side plate portion 203. The cooler 250 is in contact with the cell terminals 231 via the side plate portion 203 and the heat dissipation member 270. Therefore, the cooler 250 can cool the battery cells 230.

[0053] Furthermore, while the battery cells 230 are housed in a housing chamber, the cooler 250 is located outside the housing chamber. The housing chamber is sealed by the battery pack housing 200, the battery pack cover 110, and the base member 140. Therefore, even if the refrigerant flowing through the cooler 250 leaks out, it is possible to prevent the leaked refrigerant from coming into contact with the battery cells 230.

[0054] The cell terminals 231 are in contact with the inner surface of the side plate portion 203 via the heat dissipation member 270. Therefore, the cell terminals 231 can be cooled by the cooler 250 while heat is dissipated from the cell terminals 231 via the heat dissipation member 270. Furthermore, if a flexible resin sheet is used for the heat dissipation member 270, the contact between the cell terminals 231 and the side plate portion 203 can be improved. As a result, the battery cell 230 can be efficiently cooled by the cooler 250.

[0055] The cooler 250 is equipped with a refrigerant flow path 253, through which the refrigerant flows. This configuration allows the cooler 250 to have a higher cooling capacity compared to a system that cools by heat dissipation without using a refrigerant.

[0056] <Second Embodiment> Next, a second embodiment will be described. In this second embodiment and subsequent descriptions, elements having the same reference numerals as those used up to that point are the same as the elements with the same reference numerals in the previous embodiments, unless otherwise specified. Also, when only a part of the configuration is described, the previously described embodiments can be applied to the other parts of the configuration.

[0057] In the second embodiment, the core material 281 shown in Figure 9 is provided instead of the core material 181 of the first embodiment. Figure 9 is an end view of the core material 281. The core material 281 is provided with a fluid passage 282. The core material 281 is the same as the core material 181 except that the fluid passage 282 is formed inside.

[0058] The fluid passages 282 open to both end faces of the core material 281. Because of the fluid passages 282, the core material 281 can be said to be hollow. As shown in Figure 10, the fluid passages 282 also open to the sides of the core material 281. The sides of the core material 281 are the faces of the end faces of the battery cells 230. Therefore, the fluid passages 282 open toward the end faces of the battery cells 230. On the sides of the core material 281, openings of the fluid passages 282 are formed between each pair of frame members 190.

[0059] Figure 11 is a cross-sectional view taken along line XI-XI in Figure 10. As shown in Figure 11, in the fluid passage 282, the portion that opens to the side surface of the core material 281 is connected to the portion that penetrates both end faces of the core material 281.

[0060] Figure 12 shows the short side wall 290 of the second embodiment. The short side wall 290 is used in place of the short side wall 130. The short side wall 290 is provided with a communication hole 291. The communication hole 291 penetrates the short side wall 290 at a position opposite the fluid passage 282. Therefore, the fluid passage 282 communicates with the outside of the battery pack through the communication hole 291.

[0061] In the second embodiment, the core material 281 is provided with a fluid passage 282 inside. This fluid passage 282 communicates with the outside of the battery pack and opens toward the end face of the battery cell 230. By providing such a fluid passage 282, even if gas is generated from the battery cell 230, the gas can be discharged through the fluid passage. Since the gas discharge path can be defined in this way, if the battery pack is mounted in a vehicle and gas is generated from the battery cell 230, it is possible to suppress the release of that gas into the passenger compartment. In addition, the fluid passage 282 can also maintain the air pressure in the housing chamber that houses the battery cell 230 at the same air pressure as the outside of the battery pack.

[0062] <Third Embodiment> Figure 13 shows an external perspective view of the battery pack 300 according to the third embodiment. The battery pack cover 310 of the battery pack 300 is a substantially rectangular flat plate shape. The battery pack cover 310 has a plurality of outer concave portions 314 formed on its outer surface 311. The outer concave portions 314 are parts that are recessed from the outer flat portion 315 on the outer surface 311 of the battery pack cover 310. The material of the battery pack cover 310 is the same as that of the battery pack cover 110.

[0063] Figure 14 illustrates the long side wall 320 and short side wall 330 of the battery pack 300. The long side wall 320 and short side wall 330 not only cover the end face and sides of the battery module assembly 170, but also cover a portion of the cover-side flat plate portion 201 and the base-side flat plate portion 202 of the battery pack housing 200 from their thickness direction. Note that Figure 14 shows the battery module 210 not yet assembled. When actually assembling the battery pack 300, the long side wall 320 and short side wall 330 are attached to the battery module assembly 170 after the battery housing portion 180 has housed the battery module 210. Bolts 302 connect the equipment case 150, the battery pack cover 310, and the short side wall 330.

[0064] Figure 15 is a cross-sectional view taken along the line XV-XV in Figure 13. The battery pack cover 310 has a pressing portion 312 on its inner surface facing the battery module 210. The inner surface of the battery pack cover 310 also has an inner flat portion 313 that is in contact with the frame member 190. The pressing portion 312 is a convex shape that protrudes from the inner flat portion 313 toward the battery module 210, with the inner flat portion 313 as the reference plane. In addition, the pressing portion 312 may be formed by forming an outer concave surface portion, as in the first embodiment.

[0065] Two pressing portions 312 are formed between one frame member 190 and another frame member 190 adjacent to that frame member 190. Therefore, two pressing portions 312 are provided for one battery module 210. The length of the pressing portion 312 in the direction along the short side wall 130 is the same as that of the outer concave portion 112.

[0066] The pressing portion 312 presses against the battery module 210. Since the pressing portion 312 is in contact with the battery module 210, the pressing portion 312 directly presses against the battery module 210 from the thickness direction of the battery cells 230. The battery pack cover 310 equipped with the pressing portion 312 is a pressing member. In the battery pack cover 310, the region where the pressing portion 312 is formed is the pressing region that presses against the battery module 210.

[0067] The base member 340 has a pressing portion 342 and an inner flat portion 343 on its inner surface facing the battery module 210. The inner flat portion 343 is in contact with the frame member 190. The pressing portion 342 protrudes further toward the battery module 210 than the inner flat portion 343. The pressing portion 342 is formed in correspondence with the pressing portion 312, and the number and shape of the pressing portion 342 are the same as those of the pressing portion 312. The position where the pressing portion 342 is formed on the base member 340 is the same as the position where the pressing portion 312 is formed on the battery pack cover 310. The pressing portion 342 is in contact with the battery module 210 and directly presses the battery module 210.

[0068] The inner flat surface 313 of the battery pack cover 310 is in contact with the restricting portion 192 of the frame member 190. The inner flat surface 343 of the base member 340 is also in contact with the restricting portion 192 of the frame member 190. The frame member 190 is positioned between the battery pack cover 310 and the base member 340 and is in contact with them. The frame member 190 is a side member that seals the lateral space on the longitudinal side of the battery module 210.

[0069] Between the two pressing portions 312 that press against one battery module 210, there is a relative recess due to the formation of the pressing portions 312. A connecting refrigerant pipe 350 is provided in this portion. A connecting refrigerant pipe 350 is also provided between the two pressing portions 342 that press against one battery module 210. The connecting refrigerant pipe 350 is in contact with the battery module 210.

[0070] The connecting refrigerant piping 350 has an inlet end 161 and an outlet end 162, and is connected to the refrigerant piping that extends along the long side wall 120. Hereinafter, the refrigerant piping that has an inlet end 161 and an outlet end 162 and extends along the long side wall 120 may be referred to as the main refrigerant piping. One end of the connecting refrigerant piping 350 is connected to the main refrigerant piping which is close to the long side wall 120, and the other end is connected to the main refrigerant piping which is located in the longitudinal center of the short side wall 130. Therefore, the inside of the connecting refrigerant piping 350 becomes a refrigerant flow path 351 through which the refrigerant flows. Furthermore, the connecting refrigerant piping 350 is arranged along the longitudinal direction of the battery module 210.

[0071] Figure 16 is a cross-sectional view taken along line XVI-XVI in Figure 13. The long side wall 320 comprises a long side wall portion 321, a cover-side flat plate portion 322, and a base-side flat plate portion 323. The long side wall portion 321 has the same shape as the long side wall 120. The cover-side flat plate portion 322 extends from the longitudinal side of the long side wall portion 321 in a direction perpendicular to the long side wall portion 321 and is in contact with the inner flat surface portion 313 of the battery pack cover 310. The base-side flat plate portion 323 extends from the longitudinal side of the long side wall portion 321 in a direction perpendicular to the long side wall portion 321 and is in contact with the inner flat surface portion 343 of the base member 340. The long side wall 320 is a side member that seals the lateral space of the end face (short side surface) of the battery module 210.

[0072] The cover-side flat plate portion 201 of the battery pack housing 200 is in contact with the cover-side flat plate portion 322 of the long lateral wall 320. Therefore, the cover-side flat plate portion 201 is in contact with the battery pack cover 310 via the cover-side flat plate portion 322. The base-side flat plate portion 202 of the battery pack housing 200 is in contact with the base-side flat plate portion 323 of the long lateral wall 320. Therefore, the base-side flat plate portion 202 is in contact with the base member 340 via the base-side flat plate portion 323. With this configuration, in addition to the long lateral wall 320, the battery pack housing 200 also serves as a side member that seals the lateral space of the battery module 210. The BBM case 220 has a potted internal space. This point will be explained using Figure 21.

[0073] As shown in Figure 16, the core material 181 is also in contact with the inner flat surface 313 of the battery pack cover 310 and the inner flat surface 343 of the base member 340. Therefore, the core material 181 is also a side member that seals the lateral space of the end face (short side) of the battery module 210.

[0074] Although not shown in Figure 16, the short side wall 330 has the same configuration as the long side wall 320. That is, the short side wall 330 comprises a short side wall portion having the same shape as the short side wall 130, a cover-side flat plate portion that contacts the inner surface portion 313 of the battery pack cover 310, and a base-side flat plate portion that contacts the inner surface portion 343 of the base member 340. The short side wall 330 is a side member that seals the lateral space on the longitudinal side of the battery module 210.

[0075] The battery pack 300 configured in this way includes a battery pack cover 310 that presses the battery module 210 from the thickness direction of the battery cells 230. Therefore, the expansion of the battery cells 230 can be effectively suppressed. In addition, the battery pack cover 310 also suppresses displacement of the battery module 210 by pressing it from the thickness direction of the battery cells 230.

[0076] Furthermore, the battery pack 300 has a refrigerant flow path 351 positioned between the battery pack cover 310 and the battery module 210. The refrigerant flow path 351 allows the battery cells 230 to be cooled from the thickness direction of the battery cells 230. Therefore, the battery cells 230 can be cooled efficiently.

[0077] The pressing portion 312 has a convex shape that protrudes from the inner flat portion 313 toward the battery module 210, and the refrigerant flow path 351 is formed between the two pressing portions 312. This allows the battery module 210 to be pressed by the pressing portions 312 while being cooled by the refrigerant flowing through the refrigerant flow path 351.

[0078] The following can be said about the cooling effect: The pressing portion 312 of the battery pack cover 310 presses against the battery module 210. There is no rubber or anything similar between the battery pack cover 310 and the battery module 210. Therefore, the connecting refrigerant piping 350 is also in direct contact with the battery module 210, and the refrigerant flowing through the connecting refrigerant piping 350 can effectively cool the battery module 210.

[0079] The inside of the connected refrigerant piping 350 forms a refrigerant flow path 351. Therefore, liquid refrigerants such as water can flow through the refrigerant flow path 351. By flowing liquid refrigerant through the refrigerant flow path 351, the battery module 210 can be effectively cooled.

[0080] The battery pack 300 includes a base member 340. The base member 340 is positioned on the opposite side of the battery pack cover 310 from the battery module 210, and presses against the battery module 210 from the opposite side of the battery pack cover 310, forming the outer casing of the battery pack 300. By including this base member 340, the expansion of the battery cells 230 can be further suppressed, and the displacement of the battery module 210 can also be further suppressed. In addition, a refrigerant flow path 351 is also arranged between the base member 340 and the battery module 210, so the battery module 210 can be cooled more effectively.

[0081] The side members positioned between the battery pack cover 310 and the base member 140 and in contact with the battery pack cover 310 and the base member 140 include a core material 181, a frame member 190, a battery pack housing 200, a long side wall 320, and a short side wall 330. These side members can seal the internal space of the battery pack 300.

[0082] <Fourth Embodiment> Figure 17 shows a battery pack 400 of the fourth embodiment. The battery pack 400 comprises a plurality of battery modules 210. It also comprises a battery pack cover 310, which is included in the battery pack 300 of the third embodiment, and a base member 140, which is included in the battery pack 100 of the first embodiment. The battery pack 400 comprises a long side wall 120 and a battery pack housing 200, but Figure 17 shows the battery pack with these long side wall 120 and battery pack housing 200 removed.

[0083] The battery pack 400, as in previous embodiments, has four rows of battery modules 210, with 12 battery modules 210 in each row. These battery modules 210 are arranged in a direction intersecting the thickness direction of the battery cells 230. More specifically, these battery modules 210 are arranged in a direction perpendicular to the thickness direction of the battery cells 230. Therefore, all the battery modules 210 in the battery pack 400 are arranged on a single plane.

[0084] As can be seen from Figures 17 and 1, the overall shape of the battery module 210, in which multiple battery modules 210 are arranged, is a rectangular parallelepiped shape in which both the short side and the long side are longer than the thickness of the battery module 210.

[0085] The battery pack cover 310 is connected to other components of the battery pack 400, such as the frame member 190, by bolts 402. The base member 140 is also connected to the frame member 190 by bolts 402. In addition, in the previous embodiment, the battery pack covers 110, 310 and the base members 140, 340 can also be connected to the frame member 190, etc., by bolts. A total terminal 410 is provided at the longitudinal end of the battery pack 400.

[0086] Figure 18 is a magnified view of the area around the total terminals 410 of the battery pack 400. The BBM case 420 has the same function as the BBM case 220 of the first embodiment, except that the spacing between adjacent BBM cases 420 is different. Therefore, the BBM case 420 covers the end face of the battery module 210 on the cell terminal 231 side while exposing the cell terminals 231.

[0087] Figure 18 shows three busbars 240a, 240b, and 240c. Busbar 240b connects the battery module 210a closest to the total terminal 410 in series with the second battery module 210b from the total terminal 410 side. Busbar 240b directly connects the second battery module 210b from the total terminal 410 side with the third battery module 210 from the total terminal 410 side. In this way, the multiple battery modules 210 of the battery pack 400 are connected in series by multiple busbars 240.

[0088] The busbar 240a closest to the total terminal 410 is bent at a right angle toward the battery pack cover 310 at the portion that protrudes longitudinally from the BBM case 420 toward the base member 140. This busbar 240a is electrically connected to the terminal block 430. The total terminal 410 is connected to the terminal block 430. Therefore, the total terminal 410 is the end of the electrical path in which multiple battery modules 210 are electrically connected in series.

[0089] As shown in Figure 18, the terminal block 430 is positioned adjacent to the end battery module 210 in an array of multiple battery modules 210. The terminal block 430 is positioned in the direction of the array with respect to the end battery module 210 in the array. The total terminal 410 is coupled to the terminal block 430 and extends in a direction along the thickness direction of the battery cell 230. The direction along the thickness direction of the battery cell 230 includes the direction parallel to the thickness direction of the battery cell 230. The tip of the total terminal 410 protrudes beyond the battery module 210.

[0090] The total terminal 410 of the battery pack 400 configured in this way extends in a direction along the thickness direction of the battery cell 230, and its tip protrudes beyond the battery module 210 in the thickness direction of the battery cell 230. This configuration makes it easier to position electrical equipment connected to the total terminal 410 in the thickness direction of the battery cell 230 relative to the battery pack 400.

[0091] The battery pack 400 is equipped with multiple battery modules 210 arranged in a direction intersecting the thickness direction of the battery cells 230. This prevents the length of the battery pack 400 in the thickness direction of the battery cells from becoming excessive. For example, if the multiple battery modules 210 are arranged horizontally, the length of the battery pack 400 in the height direction can be prevented from becoming excessive.

[0092] This battery pack 400 makes it easy to position electrical equipment connected to the total terminals 410 in the thickness direction of the battery cells 230 relative to the battery pack 400. Therefore, as shown in Figure 18, the equipment case 150 can be positioned at one end of the longitudinal direction of the battery pack cover 310, in contact with the battery pack cover 310. In addition, even if electrical equipment is positioned in the thickness direction of the battery cells 230 relative to the battery pack 400, it is possible to prevent the overall length in the thickness direction of the battery cells, including the electrical equipment connected to the total terminals 410, from becoming too long.

[0093] Since the total terminal 410 is provided adjacent to the battery module 210a which is at the end of the array of multiple battery modules 210, the arrangement of the total terminal 410 and the electrical equipment connected to the total terminal 410 becomes easier.

[0094] The overall shape of the battery module, in which multiple battery modules 210 are arranged, is a rectangular parallelepiped shape in which both the short and long sides are longer than the thickness of the battery modules 210. Therefore, as shown in Figure 17, the battery pack 400 can be made thin.

[0095] <Fifth Embodiment> Figure 19 shows the battery pack 500 of the fifth embodiment. Figure 19 is a magnified view of the vicinity of the total terminals 410 in the battery pack 500, similar to Figure 18. The battery pack 500 includes a BBM case 520. Although the shape is different, the BBM case 520, like the BBM cases 220 and 420, covers the end face of the battery module 210 on the cell terminal 231 side while exposing the cell terminals 231.

[0096] In addition to the cell terminals 231, a temperature sensor 530 is exposed through an opening in the BBM case 520. The temperature sensor 530 is a sensor that detects the temperature of the battery module 210. A temperature sensor 530 can be provided for each battery module 210. Figure 19 shows two temperature sensors 530.

[0097] Similar to the FCP221 in the first embodiment, the FPC521 has multiple voltage detection lines. The voltage detection lines are connected to the cell terminals 231. Furthermore, the FPC521 also has temperature sensor lines. The temperature sensor lines are connected to the temperature sensor 530. The FPC521 is connected to the cell terminals 231 of the multiple battery modules 210 and to the multiple temperature sensors 530. The end 521a of the FPC521 on the total terminal 410 side extends parallel to the thickness direction of the battery cell 230. The tip of the end 521a protrudes beyond the battery module 210 towards the tip of the total terminal 410. The end 521a of the FPC521 is positioned in the same direction as the total terminal 410 with respect to the arrangement of the battery modules 210, and is positioned close to the total terminal 410.

[0098] Similar to the main terminal 410, the end of the FPC 521 extends parallel to the thickness direction of the battery cell 230, and the tip of its end 521a protrudes beyond the battery module 210 towards the tip of the main terminal 410. Therefore, it is easy to position devices connected to the wires formed on the FPC 521 in the thickness direction of the battery cell 230 relative to the battery pack 400.

[0099] Although embodiments have been described above, the disclosed technology is not limited to the embodiments described above. The following modifications are also included within the scope of disclosure, and further modifications can be made in various ways without departing from the gist of the invention.

[0100] <Modification 1> Figure 20 shows a frame member 690 that is different from the frame member 190 of the first embodiment. The frame member 690 has the same main frame portion 191 as the frame member 190. A pair of restricting portions 692 provided by the frame member 690 extend from the longitudinal side of the main frame portion 191 in a direction intersecting the main frame portion 191. However, unlike the restricting portion 192 of the first embodiment, the restricting portion 692 is bent at the portion connected to the main frame portion 191. The restricting portion 692 has a configuration that includes a flat plate portion extending to one side from the portion connected to the main frame portion 191 and a flat plate portion extending to the other side. The core material to which this frame member 690 is fixed has a curved shape. The battery pack also has a curved shape as a whole.

[0101] <Modification 2> As shown in Figure 21, the internal space of the BBM case 220 may be potted. That is, the internal space of the BBM case 220 may be sealed with resin. The internal space of the BBM case 420 may also be potted. Doing so improves the rigidity around the cell terminal 231 and also improves thermal conductivity.

[0102] <Modification 3> The battery pack 300 is equipped with a connecting refrigerant pipe 350, and liquid refrigerant flows through the refrigerant passage 351 inside the connecting refrigerant pipe 350. However, the connecting refrigerant pipe 350 may be omitted, and the space between the two pressing parts 312 may be used as the refrigerant passage, with gaseous refrigerant flowing through that passage.

[0103] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where paragraphs refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas. (Technical Idea 1) A battery pack comprising a plurality of battery modules (210), each comprising a plurality of plate-shaped battery cells stacked in the thickness direction of the battery cells, in a direction intersecting the thickness direction of the battery cells, and comprising a total terminal (410) which is the end of an electrical path in which the plurality of battery modules are electrically connected in series, wherein the total terminal extends in a direction along the thickness direction of the battery cells, and its tip protrudes beyond the battery module in the thickness direction of the battery cells. (Technical Idea 2) The battery pack according to Technical Idea 1, wherein the total terminal is provided adjacent to the battery module that is at the end of the array of the plurality of battery modules. (Technical Idea 3) The battery pack according to Technical Idea 1 or 2, wherein a plurality of battery modules, each having plate-shaped battery cells stacked in the thickness direction of the battery cells, are arranged in a direction intersecting the thickness direction of the battery cells, and the overall shape of the battery module formed by the arrangement of the plurality of battery modules is a rectangular parallelepiped, where both the short and long sides are longer than the thickness direction length of the battery module. (Technical Idea 4) The battery pack according to any one of Technical Ideas 1 to 3, comprising a connecting wire that is electrically connected to the plurality of battery modules, extends parallel to the thickness direction of the battery cells, and whose tip protrudes further toward the tip side of the total terminal than the battery module. (Technical Idea 5) The battery pack according to any one of Technical Ideas 1 to 4, comprising a pressing member (310) that presses the battery module from the thickness direction of the battery cells.(Technical Idea 6) The battery pack according to any one of Technical Ideas 1 to 5, wherein the battery cell is provided with cell terminals (231), and the battery pack comprises a housing chamber wall portion (203) which is the wall of a housing chamber in which the battery cell is housed, and the cell terminals are arranged on the inner wall side, and a cooler (250) which is in contact with the outer surface of the housing chamber wall portion. (Technical Idea 7) The battery pack according to any one of Technical Ideas 1 to 6, wherein the battery pack comprises a frame member (190) which is arranged in the lateral direction of the battery cell with respect to the battery module and houses the battery module, and the frame member is provided with a restricting portion (192) which faces the battery module in the thickness direction of the battery cell and restricts the movement of the battery module in the thickness direction of the battery cell. (Technical Idea 8) A battery pack according to any one of Technical Ideas 1 to 6, comprising: a frame member (190) arranged in the lateral direction of the battery cell relative to the battery module and housing the battery module; and a core member (281) to which a plurality of the frame members are connected and which faces the end faces of a plurality of the battery modules, wherein the core member has a fluid passage (282) inside, and the fluid passage communicates with the outside of the battery pack and opens toward the end faces of the battery cells.

Claims

1. A battery pack comprising a plurality of battery modules (210) in which a plurality of plate-shaped battery cells are stacked in the thickness direction of the battery cells, arranged in a direction intersecting the thickness direction of the battery cells, and comprising a total terminal (410) which is the end of an electrical path in which the plurality of battery modules are electrically connected in series, wherein the total terminal extends in a direction along the thickness direction of the battery cells, and its tip protrudes beyond the battery module in the thickness direction of the battery cells.

2. The battery pack according to claim 1, wherein the total terminal is provided adjacent to the battery module that is at the end of the array of the plurality of battery modules.

3. A battery pack according to claim 1, wherein a plurality of battery modules, each in which plate-shaped battery cells are stacked in the thickness direction of the battery cells, are arranged in a direction intersecting the thickness direction of the battery cells, and the overall shape of the battery module formed by the arrangement of the plurality of battery modules is a rectangular parallelepiped, where both the short side and the long side are longer than the length in the thickness direction of the battery module.

4. The battery pack according to claim 1, comprising a wire electrically connected to a plurality of the battery modules, the connecting wire extending parallel to the thickness direction of the battery cell, and the tip of which protrudes further toward the tip of the total terminal than the battery module.

5. The battery pack according to claim 1, further comprising a pressing member (310) for pressing the battery module from the thickness direction of the battery cell.

6. The battery pack according to claim 1, wherein the battery cell is provided with cell terminals (231), and the battery pack comprises a housing chamber wall portion (203) which is the wall of the housing chamber in which the battery cell is housed, and the cell terminals are arranged on the inner wall side, and a cooler (250) which is in contact with the outer surface of the housing chamber wall portion.

7. The battery pack according to claim 1, comprising a frame member (190) arranged in the lateral direction of the battery cell with respect to the battery module and housing the battery module, wherein the frame member faces the battery module in the thickness direction of the battery cell and comprises a restricting portion (192) that restricts the movement of the battery module in the thickness direction of the battery cell.

8. The battery pack according to claim 1, comprising: a frame member (190) arranged in the lateral direction of the battery cells with respect to the battery module and housing the battery module; and a core member (281) to which a plurality of the frame members are connected and which faces the end faces of a plurality of the battery modules, wherein the core member has a fluid passage (282) inside, the fluid passage communicates with the outside of the battery pack and opens toward the end faces of the battery cells.

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