Battery pack box body and battery pack

Abstract

The utility model provides a battery pack box body and a battery pack, and relates to the technical field of power batteries, the battery pack box body is used for accommodating and cooling a battery module, the battery pack box body comprises a first bottom plate; a mounting cavity is defined by the side plate and the first bottom plate, and the battery module is arranged in the mounting cavity; the second bottom plate is arranged outside the mounting cavity, and a liquid cooling channel is defined by the second bottom plate and the first bottom plate; wherein the liquid cooling channel is used for accommodating a cooling medium so as to cool the battery module. According to the battery module, the first bottom plate is arranged between the battery module and the liquid cooling channel, so that the battery module can uniformly dissipate heat, and meanwhile, the mounting cavity defined by the side plate and the first bottom plate can accommodate the battery module, so that the mounting stability of the battery module is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, and in particular to a battery pack box and a battery pack. Background Art

[0002] Most traditional battery packs use air cooling or passive heat dissipation, which makes it difficult to ensure uniform heat dissipation and the stability of battery operation, affecting the battery's charge and discharge efficiency and cycle life. In contrast, liquid-cooled battery packs can achieve more precise temperature control by setting liquid cooling pipes inside or around the battery pack, using circulating coolant to take away the heat generated by the battery. However, the liquid cooling pipes in the related art are independently set from the battery pack case. On the one hand, this results in a loose structure of the battery pack case and a larger volume of the battery pack case. On the other hand, the battery module is in direct contact with the liquid cooling pipe, resulting in uneven heat dissipation of the battery module, causing a large temperature difference in the battery cell and reducing the operating stability of the battery module.

[0003] Therefore, how to propose a battery pack box that can dissipate heat evenly and has a compact structure has become an urgent problem to be solved. Utility Model Content

[0004] The utility model provides a battery pack box and a battery pack, which solve the problems in the related art that the battery pack box is large in volume and the heat dissipation of the battery module is not uniform.

[0005] To this end, the first object of the present invention is to provide a battery pack case.

[0006] The second object of the present invention is to provide a battery pack.

[0007] In view of this, an embodiment of the first aspect of the utility model provides a battery pack case for accommodating and cooling a battery module, the battery pack case comprising: a first bottom plate; a side plate, which together with the first bottom plate form an installation cavity, and the battery module is arranged inside the installation cavity; a second bottom plate, which is arranged outside the installation cavity and together with the first bottom plate form a liquid cooling channel; wherein the liquid cooling channel is used to accommodate a cooling medium to cool the battery module.

[0008] According to the battery pack box body provided by the present utility model, the battery pack box body can accommodate and cool the battery module. The battery pack box body includes a first bottom plate, a side plate and a second bottom plate. Among them, the side plate and the first bottom plate enclose an installation cavity, the battery module is arranged inside the installation cavity, the second bottom plate is arranged outside the installation cavity. At the same time, the first bottom plate and the second bottom plate enclose a liquid cooling channel, and the liquid cooling channel is used to accommodate a cooling medium to cool the battery module. That is to say, the first bottom plate and the second bottom plate together form the bottom wall of the battery pack box body, a liquid cooling channel is arranged inside the bottom wall, the cooling medium can circulate in the liquid cooling channel, the battery module is arranged in the installation cavity, and the liquid cooling channel is arranged outside the installation cavity. The cooling medium in the liquid cooling channel cools the battery module through the first bottom plate. In the related art, the battery module directly contacts the liquid cooling channel, and the liquid cooling channel contacts some of the battery modules and does not contact the rest of the battery modules, resulting in uneven heat dissipation of the battery module. However, in this application, by contacting the battery module with the first bottom plate, the cold quantity can be evenly transferred to the battery module, avoiding uneven heat dissipation of the battery module and affecting the operation stability of the battery module. That is, in this application, a first bottom plate is arranged between the battery module and the liquid cooling channel, which can enable the battery module to dissipate heat evenly. At the same time, the installation cavity enclosed by the side plate and the first bottom plate can accommodate the battery module, improving the installation stability of the battery module.

[0009] Optionally, in some embodiments, the battery pack box body further includes: a rib, arranged on the second bottom plate and forming a flow channel with the second bottom plate, the rib is connected to the first bottom plate, and the first bottom plate closes the flow channel to form a liquid cooling channel.

[0010] In this embodiment, the battery pack box body further includes a rib. The rib is arranged on the second bottom plate, and the rib and the second bottom plate form a flow channel. The second bottom plate is connected to the first bottom plate through the rib, and the first bottom plate closes the flow channel to form a liquid cooling channel. That is to say, the second bottom plate and the rib form a flow channel for accommodating the cooling medium. The second bottom plate serves as the bottom wall of the flow channel, and the rib serves as the side wall of the flow channel. At the same time, the first bottom plate is connected to the rib, and the first bottom plate serves as the top wall of the flow channel, so as to enclose a liquid cooling channel by using the second bottom plate, the rib and the first bottom plate. In addition, the second bottom plate and the rib are fixedly connected, for example, by friction stir welding. Compared with the way of combining welding and bonding for the second bottom plate and the rib, it not only improves the connection strength between the rib and the second bottom plate, but also can improve the sealing performance and safety of the liquid cooling channel, preventing the leakage of the cooling medium. At the same time, using friction stir welding to connect the rib and the first bottom plate can avoid the problem of piercing the plate body compared with spot welding or other welding methods, improving the product qualification rate.

[0011] It can be understood that the second bottom plate can be formed into a rib and a flow channel by stamping, that is, the second bottom plate and the rib are integrally formed, ensuring the connection reliability between the second bottom plate and the rib. At the same time, it also reduces the preparation difficulty of the battery pack box body and reduces the production cost.

[0012] Optionally, in some embodiments, the second bottom plate includes: a liquid inlet connected to the liquid cooling channel; a liquid outlet connected to the liquid cooling channel; wherein, the liquid inlet and the liquid outlet are provided on the same side of the second bottom plate.

[0013] In this embodiment, the second bottom plate includes a liquid inlet and a liquid outlet, both of which are connected to the liquid cooling channel, that is, the liquid cooling channel is provided with a liquid inlet and a liquid outlet. The cooling medium can enter the liquid cooling channel through the liquid inlet and discharge from the liquid outlet, so as to ensure that the cooling medium can circulate continuously and improve the cooling effect of the battery module. At the same time, the liquid inlet and the liquid outlet are provided on the same side of the second bottom plate. On the one hand, it improves the convenience for users to connect the liquid inlet and the liquid outlet. On the other hand, compared with the liquid inlet and the liquid outlet being provided on the opposite sides of the second bottom plate, it can increase the length of the liquid cooling channel, thereby improving the cooling effect of the battery module.

[0014] Optionally, in some embodiments, the liquid cooling channel includes: a liquid inlet channel with one end connected to the liquid inlet; a liquid outlet channel with one end connected to the liquid outlet; and a plurality of sub-channels respectively connecting the liquid inlet channel and the liquid outlet channel.

[0015] In this embodiment, the liquid cooling channel includes a liquid inlet channel, a liquid outlet channel and a plurality of sub-channels. One end of the liquid inlet channel is connected to the liquid inlet, one end of the liquid outlet channel is connected to the liquid outlet, and the plurality of sub-channels are arranged in parallel and respectively connect the liquid inlet channel and the liquid outlet channel. That is to say, both the liquid inlet channel and the liquid outlet channel are main channels. The cooling medium enters the liquid inlet channel from the liquid inlet, and then enters the plurality of sub-channels respectively. The cooling medium in the plurality of sub-channels flows independently without interference and converges in the liquid outlet channel and finally discharges from the liquid outlet. That is, the cooling medium in the plurality of sub-channels does not affect each other and exchanges heat with the battery module independently, making the heat dissipation of the battery module more uniform and ensuring the cooling effect of the battery module.

[0016] Optionally, in some embodiments, the rib separates the plurality of sub-channels, and the first bottom plate is connected to the rib, thereby separating out a plurality of independent sub-channels and improving the sealing performance of the plurality of sub-channels. In addition, the first bottom plate and the rib are fixedly connected by friction stir welding. Even when the pressure of the cooling medium is relatively high, the cooling medium in adjacent sub-channels will not leak, and the connection strength is relatively high, and the liquid cooling channel will not deform.

[0017] Optionally, in some embodiments, the installation cavity includes a plurality of installation sub-cavities, the battery module includes multiple groups of battery units, and the installation sub-cavities are used to install the battery units, and the sub-channels are correspondingly arranged with the installation sub-cavities.

[0018] In this embodiment, the installation cavity includes a plurality of installation sub-cavities, the battery module includes multiple groups of battery cells, the installation sub-cavities are used to install the battery cells, and the sub-channels are correspondingly arranged with the installation sub-cavities. That is to say, the battery module includes multiple groups of battery cells, and the installation cavity includes a plurality of installation sub-cavities. The installation sub-cavities are used to install the battery cells. The sub-channels of each liquid cooling channel are arranged in one-to-one correspondence with each installation sub-cavity. That is, the cooling medium in each sub-channel dissipates heat to the corresponding battery cell in a targeted manner. Compared with the related art where the cooling medium first flows through a certain battery cell and then flows to other battery cells, the sub-channels corresponding to the multiple battery cells in this application are independent of each other, and the cooling capacity transferred by the cooling medium in the sub-channels to the multiple battery cells is basically the same, ensuring the cooling effect on the multiple battery cells, making the heat dissipation of the battery module more uniform, reducing the temperature difference of the battery cores inside the battery module, and improving the operating stability of the battery module.

[0019] Optionally, in some embodiments, the battery pack box body further includes: a limiting rib, which is arranged on the first bottom plate and is located inside the installation cavity. The limiting rib is used to limit the sliding of the battery module on the first bottom plate.

[0020] In this embodiment, the battery pack box body further includes a limiting rib. The limiting rib is arranged on the first bottom plate and is located inside the installation cavity. That is to say, the limiting rib is arranged inside the installation cavity, and the bottom wall of the installation cavity is the first bottom plate. The limiting rib is arranged on the first bottom plate, and the battery module is installed inside the installation cavity. The limiting rib can fix and limit the battery module, restricting the relative sliding between the battery module and the first bottom plate, and improving the installation reliability of the battery module.

[0021] Optionally, in some embodiments, the number of the limiting ribs is at least two, and they are all arranged on the first bottom plate. The spacing distance between the multiple limiting ribs is set according to the size of the battery cells. The multiple limiting ribs can just install the corresponding number of battery cells, improving the installation reliability of the battery module.

[0022] Optionally, in some embodiments, the limiting rib is provided with a fixing hole, and the position of the fixing hole corresponds to the convex rib, so as to avoid the position of the liquid cooling channel, prevent the connection between the limiting rib and the first bottom plate from affecting the flow of the cooling medium, and further improve the cooling effect of the battery module.

[0023] Optionally, in some embodiments, the battery pack box body further includes: a support frame body, which is arranged on both sides of the first bottom plate and the second bottom plate, and the support frame body connects the first bottom plate and the second bottom plate. The bottom plate of the support frame body protrudes from the bottom wall of the second bottom plate.

[0024] In this embodiment, the battery pack housing further includes a support frame, which is respectively disposed on both sides of the first bottom plate and the second bottom plate. At the same time, the support frame is connected to both the first bottom plate and the second bottom plate. Importantly, the bottom plate of the support frame protrudes from the bottom wall of the second bottom plate, that is to say, the support frame contacts the installation surface, rather than the bottom wall of the second bottom plate contacting the installation surface. Therefore, the support frame can play a role in supporting the battery module. Generally, the weight of the battery module is relatively large, while the thickness of the second bottom plate is relatively thin. The bottom plate of the support frame protruding from the bottom wall of the second bottom plate can prevent the liquid cooling channel from deforming due to bearing weight, ensuring the smooth circulation of the cooling medium, and thus improving the cooling effect of the battery module.

[0025] Optionally, in some embodiments, the support frame includes: a first support body, one end of which is connected to the first bottom plate, and the first support body is a first flange formed by bending the first bottom plate towards the second bottom plate; a second support body, one end of which is connected to the second bottom plate, and the second support body is a second flange formed by bending the second bottom plate away from the first bottom plate, and the other end of the second support body is connected to the other end of the first support body.

[0026] In this embodiment, the support frame includes a first support body and a second support body. Among them, one end of the first support body is connected to the first bottom plate, one end of the second support body is connected to the second bottom plate, and the other end of the second support body is connected to the other end of the first support body. At the same time, the first support body is a first flange formed by bending the first bottom plate towards the second bottom plate, and the second support body is a second flange formed by bending the second bottom plate away from the first bottom plate. That is to say, the first flange on the first bottom plate forms the first support body, the second flange on the second bottom plate forms the second support body, and the first support body and the second support body are connected to form a support frame, using the support frame to bear the weight of the battery pack housing, thereby preventing the flow channel from deforming and improving the smooth circulation of the cooling medium.

[0027] Optionally, in some embodiments, the first flange includes: a first concave-convex portion, which is connected to the second flange; the second flange includes: a second concave-convex portion, which is connected to the first flange; wherein, the first concave-convex portion and the second concave-convex portion are connected in a matching manner.

[0028] In this embodiment, the first flange includes a first concave-convex portion, and the first concave-convex portion is connected to the second flange. The second flange includes a second concave-convex portion, the second concave-convex portion is connected to the first flange, and the first concave-convex portion and the second concave-convex portion are connected in a matching manner. That is to say, a first concave-convex portion is formed at the edge of the first flange, a second concave-convex portion is formed at the edge of the second flange, and the first concave-convex portion and the second concave-convex portion are connected in a matching manner, avoiding relative sliding between the first bottom plate and the second bottom plate. Especially when welding the first bottom plate and the second bottom plate, the first concave-convex portion and the second concave-convex portion can be used for positioning first, improving the connection quality of the first bottom plate and the second bottom plate.

[0029] Optionally, in some embodiments, both the first concave-convex part and the second concave-convex part are dovetail groove structures. Both the first concave-convex part and the second concave-convex part are provided with a concave part and a convex part, and the shapes of the concave part and the convex part of the two are complementary. The shape of the concave part is narrow outside and wide inside, and the shape of the convex part is wide outside and narrow inside. After the first concave-convex part and the second concave-convex part are connected, relative sliding between the first bottom plate and the second bottom plate in any direction can be avoided, and connecting the first bottom plate and the second bottom plate in any way will not affect the connection quality.

[0030] Optionally, in some embodiments, the first bottom plate and the second bottom plate are aluminum alloy plates. The yield strength of the aluminum alloy plate is greater than 180 Mpa, and the thermal conductivity of the aluminum alloy plate is greater than 180 W / m·K.

[0031] In this embodiment, the first bottom plate and the second bottom plate are aluminum alloy plates. The yield strength of the aluminum alloy plate is greater than 180 Mpa, and the thermal conductivity of the aluminum alloy plate is greater than 180 W / m·K. It can be understood that the aluminum alloy plates used in this application include 5-series high-strength aluminum alloy plates and 6-series high-strength aluminum alloy plates. Among them, the 5-series high-strength aluminum alloy plates mainly contain aluminum and magnesium, and the magnesium content is usually between 3% and 5%. The 6-series high-strength aluminum alloy plates mainly contain aluminum, magnesium and silicon. The 5-series high-strength aluminum alloy plates and 6-series high-strength aluminum alloy plates have higher strength than general aluminum alloy plates, which can ensure the strength of the first bottom plate and the second bottom plate, avoid deformation of the liquid cooling channel, and thus improve the service life and reliability of the battery pack box body. At the same time, the aluminum alloy plate has higher heat conduction efficiency, which can further improve the heat exchange efficiency between the cooling medium and the battery module.

[0032] An embodiment of the second aspect of the present invention provides a battery pack, including at least one battery pack box body proposed in the first aspect embodiment. The battery pack further includes: a battery module, disposed in the installation cavity surrounded by the first bottom plate and the side plate, and the battery module is in contact with the first bottom plate.

[0033] According to the battery pack proposed in this application, including at least one battery pack box body proposed in the first aspect embodiment, therefore, it has all the beneficial effects of the battery pack box body proposed in the first aspect embodiment. At the same time, the battery pack further includes a battery module. The battery module is disposed in the installation cavity surrounded by the first bottom plate and the side plate. The liquid cooling channel is arranged outside the installation cavity. The battery module exchanges heat with the liquid cooling channel through the first bottom plate. The battery module is in contact with the first bottom plate, which improves the heat dissipation uniformity of the battery module.

[0034] Optionally, in some embodiments, the battery module is bonded to the first bottom plate through a thermal conductive adhesive, which not only ensures the heat transfer effect but also improves the connection reliability of the battery module.

[0035] Additional aspects and advantages of the present utility model will become apparent in the following description section, or be learned through the practice of the present utility model. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0037] Figure 1 is a schematic structural diagram of a battery pack box body according to an embodiment provided by the present utility model;

[0038] Figure 2 is a schematic structural diagram of the interior of a battery pack according to an embodiment provided by the present utility model;

[0039] Figure 3 is one of the schematic structural diagrams of a first bottom plate and a second bottom plate according to an embodiment provided by the present utility model;

[0040] Figure 4 is a schematic structural diagram of a battery pack according to an embodiment provided by the present utility model;

[0041] Figure 5 is a schematic structural diagram of a second bottom plate according to an embodiment provided by the present utility model;

[0042] Figure 6 is the second of the schematic structural diagrams of a first bottom plate and a second bottom plate according to an embodiment provided by the present utility model;

[0043] Figure 7 is a schematic structural diagram of a first bottom plate according to an embodiment provided by the present utility model.

[0044] Among them, Figures 1 to 7 the corresponding relationship between the reference numerals and the component names in

[0045] 1 battery pack box body, 11 first bottom plate, 111 first flanging, 1111 first concave-convex part, 12 side plate, 13 installation cavity, 131 installation sub-cavity, 14 second bottom plate, 141 flow channel, 142 liquid inlet, 143 liquid outlet, 144 second flanging, 1441 second concave-convex part, 15 liquid cooling channel, 151 liquid inlet channel, 152 liquid outlet channel, 153 sub-channel, 16 convex rib, 17 limit rib, 171 fixing hole, 18 support frame body, 181 first support body, 182 second support body, 2 battery module, 21 battery cell, 3 battery pack. Detailed Embodiments

[0046] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0047] An embodiment of the first aspect of the present utility model provides a battery pack housing 1, as Figure 1 and Figure 2 shown, the battery pack housing 1 can accommodate and cool the battery module 2. The battery pack housing 1 includes a first bottom plate 11, a side plate 12, and a second bottom plate 14. Among them, the side plate 12 and the first bottom plate 11 enclose an installation cavity 13, the battery module 2 is disposed inside the installation cavity 13, and the second bottom plate 14 is disposed outside the installation cavity 13. At the same time, as Figure 3 shown, the first bottom plate 11 and the second bottom plate 14 enclose a liquid cooling channel 15. The liquid cooling channel 15 is used to accommodate a cooling medium to cool the battery module 2. That is to say, the first bottom plate 11 and the second bottom plate 14 jointly form the bottom wall of the battery pack housing 1, and the liquid cooling channel 15 is provided inside the bottom wall. The cooling medium can circulate in the liquid cooling channel 15. The battery module 2 is disposed in the installation cavity 13, and the liquid cooling channel 15 is provided outside the installation cavity 13. The cooling medium in the liquid cooling channel 15 cools the battery module 2 through the first bottom plate 11. In the related art, the battery module is in direct contact with the liquid cooling channel, and the liquid cooling channel is in contact with some battery modules and not in contact with the rest of the battery modules, resulting in uneven heat dissipation of the battery module. In this application, by contacting the battery module 2 with the first bottom plate 11, the cold quantity can be evenly transferred to the battery module 2, avoiding uneven heat dissipation of the battery module 2 and affecting the operation stability of the battery module 2. That is, in this application, the first bottom plate 11 is provided between the battery module 2 and the liquid cooling channel 15, which can enable the battery module 2 to dissipate heat evenly. At the same time, the installation cavity 13 enclosed by the side plate 12 and the first bottom plate 11 can accommodate the battery module 2, improving the installation stability of the battery module 2.

[0048] Optionally, in some embodiments, as Figure 3 shown, the battery pack housing 1 further includes: a rib 16, disposed on the second bottom plate 14 and forming a flow channel 141 with the second bottom plate 14. The rib 16 is connected to the first bottom plate 11, and the first bottom plate 11 closes the flow channel 141 to form the liquid cooling channel 15.

[0049] In this embodiment, the battery pack housing 1 further includes a rib 16 provided on the second bottom plate 14. The rib 16 and the second bottom plate 14 form a flow channel 141. The second bottom plate 14 is connected to the first bottom plate 11 through the rib 16, and the first bottom plate 11 closes the flow channel 141 to form a liquid cooling channel 15. That is to say, the second bottom plate 14 and the rib 16 form a flow channel 141 for accommodating the cooling medium. The second bottom plate 14 serves as the bottom wall of the flow channel 141, and the rib 16 serves as the side wall of the flow channel 141. At the same time, the first bottom plate 11 is connected to the rib 16, and the first bottom plate 11 serves as the top wall of the flow channel 141, so as to enclose the liquid cooling channel 15 by using the second bottom plate 14, the rib 16 and the first bottom plate 11. In addition, the second bottom plate 14 and the rib 16 are fixedly connected, for example, by friction stir welding. Compared with the way of combining welding and bonding for the second bottom plate 14 and the rib 16, it not only improves the connection strength between the rib 16 and the second bottom plate 14, but also can improve the sealing performance and safety of the liquid cooling channel 15 to prevent the leakage of the cooling medium. At the same time, connecting the rib 16 and the first bottom plate 11 by friction stir welding can avoid the problem of piercing the plate body compared with spot welding or other welding methods, and improve the product qualification rate.

[0050] It can be understood that the second bottom plate 14 can be formed into the rib 16 and the flow channel 141 by stamping, that is, the second bottom plate 14 and the rib 16 are integrally formed, which ensures the connection reliability between the second bottom plate 14 and the rib 16. At the same time, it also reduces the preparation difficulty of the battery pack housing 1 and the production cost.

[0051] Optionally, in some embodiments, as Figure 4 shown, the second bottom plate 14 includes: an inlet 142 communicating with the liquid cooling channel 15; an outlet 143 communicating with the liquid cooling channel 15; wherein, the inlet 142 and the outlet 143 are provided on the same side of the second bottom plate 14.

[0052] In this embodiment, the second bottom plate 14 includes an inlet 142 and an outlet 143. Both the inlet 142 and the outlet 143 are connected to the liquid cooling channel 15, that is, the liquid cooling channel 15 is provided with an inlet 142 and an outlet 143. The cooling medium can enter the liquid cooling channel 15 through the inlet 142 and discharge from the liquid cooling channel 15 through the outlet 143, so as to ensure the continuous circulation of the cooling medium and improve the cooling effect of the battery module 2. At the same time, the inlet 142 and the outlet 143 are provided on the same side of the second bottom plate 14. On the one hand, it improves the convenience for users to connect the inlet 142 and the outlet 143. On the other hand, compared with the inlet 142 and the outlet 143 being provided on the opposite sides of the second bottom plate 14, it can increase the length of the liquid cooling channel 15, thereby improving the cooling effect of the battery module 2.

[0053] Optionally, in some embodiments, as Figure 5As shown, the liquid cooling channel 15 includes: an inlet channel 151 with one end communicating with the inlet port 142; an outlet channel 152 with one end communicating with the outlet port 143; and a plurality of sub-channels 153 respectively communicating with the inlet channel 151 and the outlet channel 152.

[0054] In this embodiment, the liquid cooling channel 15 includes an inlet channel 151, an outlet channel 152 and a plurality of sub-channels 153. One end of the inlet channel 151 communicates with the inlet port 142, one end of the outlet channel 152 communicates with the outlet port 143, and the plurality of sub-channels 153 are arranged in parallel and respectively communicate with the inlet channel 151 and the outlet channel 152. Figure 5 The arrow direction in shows the flow direction of the cooling medium. That is to say, both the inlet channel 151 and the outlet channel 152 are main channels. The cooling medium enters the inlet channel 151 from the inlet port 142, and then enters into the plurality of sub-channels 153 respectively. The cooling medium in the plurality of sub-channels 153 flows independently without interference, and converges in the outlet channel 152 and finally discharges from the outlet port 143. That is, the cooling medium in the plurality of sub-channels 153 does not affect each other, independently exchanges heat with the battery module 2, making the heat dissipation of the battery module 2 more uniform and ensuring the cooling effect of the battery module 2.

[0055] Optionally, in some embodiments, as Figure 3 and Figure 5 shown, the rib 16 isolates the plurality of sub-channels 153, and the first bottom plate 11 is connected to the rib 16, thereby separating out a plurality of independent sub-channels 153 and improving the sealing performance of the plurality of sub-channels 153. In addition, the first bottom plate 11 and the rib 16 are fixedly connected by friction stir welding. Even when the pressure of the cooling medium is relatively large, the cooling medium in the adjacent plurality of sub-channels 153 will not be communicated, and the connection strength is relatively high, and the liquid cooling channel 15 will not be deformed.

[0056] Optionally, in some embodiments, as Figure 1 and Figure 2 shown, the installation cavity 13 includes a plurality of installation sub-cavities 131, the battery module 2 includes multiple groups of battery cells 21, the installation sub-cavities 131 are used for installing the battery cells 21, and the sub-channels 153 are arranged corresponding to the installation sub-cavities 131.

[0057] In this embodiment, the installation cavity 13 includes a plurality of installation sub-cavities 131. The plurality of sub-cavities 131 are arranged longitudinally or transversely. The battery module 2 includes multiple groups of battery cells 21. The installation sub-cavities 131 are used to install the battery cells 21. The multiple groups of battery cells 21 are also arranged longitudinally or transversely. The arrangement directions of the plurality of sub-cavities 131 and the multiple groups of battery cells 21 are the same. The sub-channels 153 are correspondingly arranged with the installation sub-cavities 131. That is to say, the battery module 2 includes multiple groups of battery cells 21, and the installation cavity 13 includes a plurality of installation sub-cavities 131. The installation sub-cavities 131 are used to install the battery cells 21. The sub-channels 153 of each liquid cooling channel 15 are arranged in one-to-one correspondence with each installation sub-cavity 131. That is, the cooling medium in each sub-channel 153 conducts directional heat dissipation to the corresponding battery cell 21. Compared with the related art where the cooling medium first flows through a certain battery cell and then flows to other battery cells. In this application, the sub-channels 153 corresponding to the multiple battery cells 21 are independent of each other, and the cooling capacity transferred by the cooling medium in the sub-channels 153 to the multiple battery cells 21 is basically the same, ensuring the cooling effect on the multiple battery cells 21, making the heat dissipation of the battery module 2 more uniform, reducing the temperature difference of the battery cores inside the battery module 2, and improving the operation stability of the battery module 2.

[0058] Optionally, in some embodiments, such as Figure 3 shown, the battery pack housing 1 further includes: a limiting rib 17, which is arranged on the first bottom plate 11 and is located inside the installation cavity 13. The limiting rib 17 is used to limit the sliding of the battery module 2 on the first bottom plate 11.

[0059] In this embodiment, the battery pack housing 1 further includes a limiting rib 17. The limiting rib 17 is arranged on the first bottom plate 11 and is located inside the installation cavity 13. That is to say, the limiting rib 17 is arranged inside the installation cavity 13, and the bottom wall of the installation cavity 13 is the first bottom plate 11. The limiting rib 17 is arranged on the first bottom plate 11, and the battery module 2 is installed inside the installation cavity 13. The limiting rib 17 can fix and limit the battery module 2, restricting the relative sliding between the battery module 2 and the first bottom plate 11, and improving the installation reliability of the battery module 2.

[0060] Optionally, in some embodiments, the number of the limiting ribs 17 is at least two, and they are all arranged on the first bottom plate 11. The interval distance between the multiple limiting ribs 17 is set according to the size of the battery cells 21. The multiple limiting ribs 17 can just install the corresponding number of battery cells 21, improving the installation reliability of the battery module 2.

[0061] Optionally, in some embodiments, such as Figure 3As shown, the limiting rib 17 is provided with a fixing hole 171, and the position of the fixing hole 171 corresponds to the convex rib 16, so as to avoid the position of the liquid cooling channel 15, prevent the connection between the limiting rib 17 and the first bottom plate 11 from affecting the flow of the cooling medium, and further improve the cooling effect of the battery module 2.

[0062] Optionally, in some embodiments, as Figure 2 and Figure 4 shown, the battery pack housing 1 further includes: a support frame 18, which is provided on both sides of the first bottom plate 11 and the second bottom plate 14, and the support frame 18 connects the first bottom plate 11 and the second bottom plate 14, and the bottom plate of the support frame 18 protrudes from the bottom wall of the second bottom plate 14.

[0063] In this embodiment, the battery pack housing 1 further includes a support frame 18. The support frame 18 is respectively arranged on both sides of the first bottom plate 11 and the second bottom plate 14. At the same time, the support frame 18 not only connects the first bottom plate 11 but also connects the second bottom plate 14. Importantly, the bottom plate of the support frame 18 protrudes from the bottom wall of the second bottom plate 14, that is to say, the support frame 18 contacts the installation surface, rather than the bottom wall of the second bottom plate 14 contacting the installation surface. Therefore, the support frame 18 can play a role in supporting the battery module 2. Generally, the weight of the battery module 2 is relatively large, and the thickness of the second bottom plate 14 is relatively thin. The bottom plate of the support frame 18 protruding from the bottom wall of the second bottom plate 14 can avoid the liquid cooling channel from bearing weight and deforming, ensuring the smooth circulation of the cooling medium, and further improving the cooling effect of the battery module 2.

[0064] Optionally, in some embodiments, as Figure 5 、 Figure 6 and Figure 7 shown, the support frame 18 includes: a first support body 181, one end of which is connected to the first bottom plate 11, and the first support body 181 is a first flanging 111 formed by bending the first bottom plate 11 in the direction of the second bottom plate 14; a second support body 182, one end of which is connected to the second bottom plate 14, and the second support body 182 is a second flanging 144 formed by bending the second bottom plate 14 in the direction away from the first bottom plate 11, and the other end of the second support body 182 is connected to the other end of the first support body 181.

[0065] In this embodiment, the support frame 18 includes a first support body 181 and a second support body 182. One end of the first support body 181 is connected to the first bottom plate 11, one end of the second support body 182 is connected to the second bottom plate 14, and the other end of the second support body 182 is connected to the other end of the first support body 181. At the same time, the first support body 181 is a first flanging 111 formed by bending the first bottom plate 11 in the direction of the second bottom plate 14, and the second support body 182 is a second flanging 144 formed by bending the second bottom plate 14 in the direction away from the first bottom plate 11. That is to say, the first flanging 111 on the first bottom plate 11 forms the first support body 181, the second flanging 144 on the second bottom plate 14 forms the second support body 182, and the first support body 181 and the second support body 182 are connected to form the support frame 18. The support frame 18 is used to bear the weight of the battery pack box body 1, thereby preventing the flow channel 141 from deforming and improving the circulation smoothness of the cooling medium.

[0066] Optionally, in some embodiments, such as Figure 5 and Figure 7 shown, the first flanging 111 includes: a first concave-convex portion 1111, which is connected to the second flanging 144; the second flanging 144 includes: a second concave-convex portion 1441, which is connected to the first flanging 111; wherein, the first concave-convex portion 1111 is connected to the second concave-convex portion 1441 in a matching manner.

[0067] In this embodiment, the first flanging 111 includes a first concave-convex portion 1111, and the first concave-convex portion 1111 is connected to the second flanging 144. The second flanging 144 includes a second concave-convex portion 1441, the second concave-convex portion 1441 is connected to the first flanging 111, and the first concave-convex portion 1111 is connected to the second concave-convex portion 1441 in a matching manner. That is to say, a first concave-convex portion 1111 is formed at the edge of the first flanging 111, a second concave-convex portion 1441 is formed at the edge of the second flanging 144, and the first concave-convex portion 1111 is connected to the second concave-convex portion 1441 in a matching manner, avoiding relative sliding between the first bottom plate 11 and the second bottom plate 14. Especially when welding the first bottom plate 11 and the second bottom plate 14, the first concave-convex portion 1111 and the second concave-convex portion 1441 can be used for positioning first, improving the connection quality between the first bottom plate 11 and the second bottom plate 14.

[0068] Optionally, in some embodiments, both the first concavo-convex portion 1111 and the second concavo-convex portion 1441 are dovetail groove structures. Both the first concavo-convex portion 1111 and the second concavo-convex portion 1441 are provided with a concave portion and a convex portion. The concave and convex portions of the two are complementary in shape. The shape of the concave portion is narrow outside and wide inside, and the shape of the convex portion is wide outside and narrow inside. After the first concavo-convex portion 1111 and the second concavo-convex portion 1441 are connected, relative sliding between the first bottom plate 11 and the second bottom plate 14 in any direction can be avoided, and connecting the first bottom plate 11 and the second bottom plate 14 in any way will not affect the connection quality.

[0069] Optionally, in some embodiments, the first bottom plate 11 and the second bottom plate 14 are aluminum alloy plates. The yield strength of the aluminum alloy plate is greater than 180 Mpa, and the thermal conductivity of the aluminum alloy plate is greater than 180 W / m·K.

[0070] In this embodiment, the first bottom plate 11 and the second bottom plate 14 are aluminum alloy plates. The yield strength of the aluminum alloy plate is greater than 180 Mpa, and the thermal conductivity of the aluminum alloy plate is greater than 180 W / m·K. It can be understood that the aluminum alloy plates used in this application include 5-series high-strength aluminum alloy plates and 6-series high-strength aluminum alloy plates. Among them, the 5-series high-strength aluminum alloy plates mainly contain aluminum and magnesium, and the magnesium content is usually between 3% and 5%. The 6-series high-strength aluminum alloy plates mainly contain aluminum, magnesium and silicon. The 5-series high-strength aluminum alloy plates and 6-series high-strength aluminum alloy plates have higher strength than ordinary aluminum alloy plates, which can ensure the strength of the first bottom plate 11 and the second bottom plate 14, avoid deformation of the liquid cooling channel 15, and thus improve the service life and reliability of the battery pack housing 1. At the same time, the aluminum alloy plate has higher thermal conductivity, which can further improve the heat exchange efficiency between the cooling medium and the battery module 2.

[0071] An embodiment of the second aspect of the present invention provides a battery pack 3, as Figure 4 shown, including at least one battery pack housing 1 proposed in the first aspect embodiment. The battery pack 3 further includes: a battery module 2, disposed in the installation cavity 13 surrounded by the first bottom plate 11 and the side plate 12, and the battery module 2 is in contact with the first bottom plate 11.

[0072] According to the battery pack 3 proposed in this application, including at least one battery pack housing 1 proposed in the first aspect embodiment, therefore, it has all the beneficial effects of the battery pack housing 1 proposed in the first aspect embodiment. At the same time, the battery pack 3 further includes a battery module 2. The battery module 2 is disposed in the installation cavity 13 surrounded by the first bottom plate 11 and the side plate 12. The liquid cooling channel 15 is arranged outside the installation cavity 13. The battery module 2 exchanges heat with the liquid cooling channel 15 through the first bottom plate 11. The battery module 2 is in contact with the first bottom plate 11, which improves the heat dissipation uniformity of the battery module 2.

[0073] Optionally, in some embodiments, the battery module 2 is adhesively bonded to the first bottom plate 11 with thermal conductive adhesive, which not only ensures the heat transfer effect but also improves the connection reliability of the battery module 2.

[0074] In a specific application, the present utility model relates to a battery pack housing (battery pack box body 1), a battery pack 3, and a power device, such as Figure 1 , Figure 2 and Figure 3 As shown, the battery pack housing includes: a liquid-cooled bottom case (the first bottom plate 11 and the second bottom plate 14), disposed at the bottom of the battery pack 3, in contact with the battery module 2 through thermal conductive adhesive; a battery pack housing (side plate 12), disposed around the battery pack 3; the battery module 2 is disposed on the liquid-cooled bottom case; the temperature equalizing upper plate (the first bottom plate 11) is the upper plate structure of the liquid-cooled bottom case, having the function of evenly transferring the temperature of the fluid and the flow channel 141 to the battery cells and carrying the battery module 2; the stamping bottom plate (the second bottom plate 14) is the lower layer of the liquid-cooled bottom case, and the stamping bottom plate is a stamping-formed flow channel structure. The coolant (cooling medium) flows in from the liquid inlet 142 and flows out from the liquid outlet 143. It is connected to the temperature equalizing upper plate by friction stir welding to form a sealed and reliable flow channel cavity. Load-bearing structures are designed on both sides to jointly bear the weight of the battery pack 3 with the temperature equalizing upper plate; the liquid inlet 142 is the coolant inlet; the liquid outlet 143 is the coolant outlet; the module fixing beam (limiting rib 17) is used to fix the battery module 2.

[0075] The battery pack housing, the battery pack 3, and the power device of the present utility model include: a liquid-cooled bottom case, a battery pack housing, a battery module 2, a temperature equalizing upper plate, a stamping bottom plate, a liquid inlet 142, a liquid outlet 143, and a module fixing beam. The liquid-cooled bottom case is made of 5-series or 6-series aluminum alloy with high strength and high thermal conductivity (the yield strength is required to be > 180 Mpa, and the thermal conductivity is > 180 W / m·K).

[0076] As Figure 1 , Figure 2 and Figure 4 As shown, the liquid-cooled bottom case and the battery pack housing form a complete cavity to enclose the battery module 2 therein. Among them, the liquid inlet 142 and the liquid outlet 143 are disposed outside the cavity of the battery pack 3. The battery module 2 is installed on the liquid-cooled bottom case and is in direct contact with the temperature equalizing upper plate. The coolant flows through the internal flow channel (liquid cooling channel 15) of the liquid-cooled bottom case, and the heat transfer between the coolant and the battery module 2 is completed by using the aluminum bottom case with high thermal conductivity.

[0077] As Figure 3 shown, the liquid-cooled housing mainly consists of a temperature equalizing upper plate, a stamping bottom plate, a liquid inlet 142, a liquid outlet 143, and a module fixing beam. The liquid inlet 142 and the liquid outlet 143 are welded to the temperature equalizing upper plate. There are two front and rear module fixing beams. The module fixing beams avoid the flow channel structure and are riveted to the temperature equalizing upper plate to play the role of fixing the battery module 2. As Figure 5, Figure 6 and Figure 7 As shown, the upper temperature - equalizing plate and the stamping bottom plate are respectively designed with an upper - plate bearing structure (the first support body 181) and a bottom - plate bearing structure (the second support body 182). The height of this structure exceeding the flow channel 141 contacts the installation and fixing surface of the battery pack 3. The two upper and lower aluminum plates jointly bear the weight of the entire battery pack 3. Among them, the stamping bottom plate and the upper temperature - equalizing plate on the contact surface are designed with a dovetail groove structure that interlocks with each other. This structure does not affect the forming process of the liquid - cooled bottom shell. After the liquid - cooled bottom shell is installed, the two plates are limited to each other and will not shift or misalign. This is beneficial to the mutual positioning between the two aluminum plates during the process and also beneficial to the uniform stress of the bearing structure.

[0078] As Figure 5 shown, the coolant is divided into four parts after entering from the inlet in the liquid - cooling channel 15, corresponding to the four battery cells 21 in the battery pack 3 respectively, and finally flows out from the outlet after confluence. Each battery cell 21 has a hot - cold winding design for the flow channel to balance the temperature between the flow channels (sub - channels 153 and sub - channels 153). The shaded area around the flow channel is the welding area (rib 16) of friction stir welding. Friction stir welding is used to form a sealed coolant cavity (liquid - cooling channel 15) between the two aluminum plates, and welding is also carried out along the flow channel on the inner side. On the one hand, it isolates the liquid between the flow channels to prevent the liquid from flowing through each other and affecting the thermal management effect. On the other hand, if the flow channels with a large distance are not welded to connect the two aluminum plates together, the stress area will be too large under the action of the coolant pressure, resulting in bulging and deformation of a single flow channel. Taking the aluminum plate thickness of 2.0 mm as an example, through simulation calculation and a large number of experimental tests, the interval distance of the welding area of friction stir welding should be ≤ 55 mm under the normal working pressure of the flow channel. If the plate thickness increases, this interval distance can be relaxed. If the plate thickness decreases, the interval distance of the friction stir welding area should be reduced to avoid the deformation of the flow channel and the thermal management not reaching the design expectation, or even the flow channel being deformed and torn.

[0079] The utility model optimizes the layout of the liquid - cooling pipeline to reduce the temperature difference between the battery cores in the battery pack 3, uses materials with higher thermal conductivity to improve the heat - transfer efficiency between the battery cores and the coolant, and uses a safer and more reliable welding method, such as friction stir welding (FSW), to seal - connect the flow - channel cavity, preventing the penetration of the flow channel, reducing the risk of coolant leakage from the flow channel, reducing the number of structural parts and the material thickness in the design to improve the energy density of the battery pack 3, and comprehensively improving the thermal management performance, safety and economy of the liquid - cooled battery pack.

[0080] In addition, in the present utility model, descriptions such as "first", "second", etc. are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0081] In the present utility model, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0082] In addition, the technical solutions between various embodiments of the present utility model can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0083] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A battery pack box, characterized in that: Used to accommodate and cool the battery module, the battery pack box includes: First base plate; The side plate and the first bottom plate enclose a mounting cavity, and the battery module is arranged inside the mounting cavity; A second bottom plate is arranged outside the installation cavity and forms a liquid cooling channel with the first bottom plate; Wherein, the liquid cooling channel is used to accommodate a cooling medium to cool the battery module.

2. The battery pack case according to claim 1, characterized in that: Also includes: The convex rib is provided on the second bottom plate and forms a flow channel with the second bottom plate. The convex rib is connected to the first bottom plate, and the first bottom plate closes the flow channel to form the liquid cooling channel.

3. The battery pack case according to claim 1, characterized in that: The second bottom plate comprises: a liquid inlet, connected to the liquid cooling channel; a liquid outlet, connected to the liquid cooling channel; Wherein, the liquid inlet and the liquid outlet are arranged on the same side of the second bottom plate.

4. The battery pack case according to claim 3, characterized in that: The liquid cooling channel comprises: A liquid inlet channel, one end of which is connected to the liquid inlet; A liquid outlet channel, one end of which is connected to the liquid outlet; A plurality of sub-channels are respectively connected to the liquid inlet channel and the liquid outlet channel.

5. The battery pack case according to claim 4, characterized in that: The mounting cavity includes a plurality of mounting sub-cavities, the battery module includes a plurality of battery cells, the mounting sub-cavities are used to mount the battery cells, and the sub-channels are arranged corresponding to the mounting sub-cavities.

6. The battery pack case according to claim 1, characterized in that: Also includes: The limiting ribs are arranged on the first bottom plate and located inside the installation cavity, and the limiting ribs are used to limit the battery module from sliding on the first bottom plate.

7. The battery pack case according to claim 1, characterized in that: Also includes: The support frame is arranged on both sides of the first bottom plate and the second bottom plate, and the support frame connects the first bottom plate and the second bottom plate, and the bottom plate of the support frame protrudes from the bottom wall of the second bottom plate.

8. The battery pack case according to claim 7, characterized in that: The support frame comprises: A first support body, one end of which is connected to the first bottom plate, and the first support body is a first flange formed by bending the first bottom plate toward the second bottom plate; The second support body has one end connected to the second bottom plate. The second support body is a second flange formed by bending the second bottom plate in a direction away from the first bottom plate. The other end of the second support body is connected to the other end of the first support body.

9. The battery pack case according to claim 8, characterized in that: The first flange comprises: a first concave-convex portion connected to the second flange; The second flange comprises: a second concave-convex portion connected to the first flange; Wherein, the first concave-convex portion is cooperatively connected with the second concave-convex portion.

10. The battery pack case according to any one of claims 1 to 9, characterized in that: The first bottom plate and the second bottom plate are aluminum alloy plates, the yield strength of the aluminum alloy plates is greater than 180 MPa, and the thermal conductivity of the aluminum alloy plates is greater than 180 W / m·K.

11. A battery pack, characterized in that: The battery pack comprises at least one battery pack case according to any one of claims 1 to 10, wherein the battery pack further comprises: The battery module is arranged in the installation cavity surrounded by the first bottom plate and the side plate, and the battery module is in contact with the first bottom plate.

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