Battery pack and vehicle

Abstract

The present invention relates to a battery pack and a vehicle, the battery pack includes a liquid cooling plate and a battery stack, the battery stack includes at least one battery module; the liquid cooling plate includes a liquid cooling plate body, a water inlet and a water outlet, a liquid cooling circuit is arranged in the liquid cooling plate body, the liquid cooling circuit includes an edge water inlet channel, a water outlet collecting channel and an intermediate channel connected between the edge water inlet channel and the water outlet collecting channel, the water inlet is connected to the liquid cooling plate body and connected to the edge water inlet channel, the water outlet is connected to the liquid cooling plate body and connected to the water outlet collecting channel. The battery pack of the present application can match the heating requirements of different areas under low temperature conditions, giving more heat to the edge area of ​​the battery pack to control the temperature difference of the battery pack.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a battery pack and a vehicle. Background Art

[0002] like Figure 1 As shown, an existing battery pack structure with a thermal management system has the following structures from top to bottom in the height direction: sealing cover 1a-fireproof insulation cotton 2a-battery module 3a-thermal conductive glue 4a-liquid cooling plate 5a-PU (Polyurethane) insulation board 6a-tray 7a. The upper surface of the battery module 3a is insulated and fireproofed by the fireproof insulation cotton 2a for the sealing cover 1a. The thermal conductivity of the fireproof insulation cotton 2a is generally around 0.02W / (mK), and has good high temperature resistance. Thermal conductive glue 4a is filled between the battery module 3a and the liquid cooling plate 5a. The thermal conductive glue 4a is of a single type and is evenly applied to the bottom of the battery module 3a. The thermal conductive glue 4a only has the function of heat conduction and does not have structural strength. The liquid cooling plate 5a is a harmonica tube structure, and the manifold structure requires a certain space to be left between the battery module 3a and the tray 7a frame. The PU heat insulation board 6a is placed between the liquid cooling plate 5a and the tray 7a to reduce the heat transfer loss from the liquid cooling plate 5a to the tray 7a and to support the liquid cooling plate 5a. The battery module 3a is fixed to the cross beam of the tray 7a through the flange surface on the module side plate. The cross beam of the tray 7a is the main heat transfer channel from the battery module 3a to the tray 7a.

[0003] In the existing battery pack structure, the battery module 3a and the tray 7a are not tightly connected, leaving a large insulation distance. Therefore, the temperature field of the battery module 3a is less affected by the external environment, and the heat load between different battery modules 3a and different areas is relatively balanced.

[0004] However, the existing battery pack structure has the following disadvantages:

[0005] (1) The use of space is not compact enough, the space utilization rate is low, the free volume is large, and there are many risk points of condensation.

[0006] (2) There are many thermal management components and the degree of integration is low, which is not conducive to reducing costs.

[0007] (3) The differences in heat loads of different battery modules and different parts are not taken into consideration, which is not conducive to controlling the temperature difference of the battery pack, improving the low-temperature performance of the battery pack, and further obtaining a more compact battery pack. Summary of the invention

[0008] The technical problem to be solved by the present invention is: to provide a battery pack and a vehicle in view of the problem that the existing battery pack structure with a thermal management system is not conducive to controlling the temperature difference of the battery pack.

[0009] To solve the above technical problems, on the one hand, an embodiment of the present invention provides a battery pack, including a liquid cooling plate and a battery stack, wherein the battery stack includes at least one battery module;

[0010] The liquid cooling plate comprises a liquid cooling plate body, a water inlet and a water outlet, a liquid cooling circuit is arranged in the liquid cooling plate body, the liquid cooling circuit comprises an edge water inlet flow channel, a water outlet collection flow channel and an intermediate flow channel connected between the edge water inlet flow channel and the water outlet collection flow channel, the water inlet is connected to the liquid cooling plate body and communicates with the edge water inlet flow channel, the water outlet is connected to the liquid cooling plate body and communicates with the water outlet collection flow channel;

[0011] The edge water inlet channel surrounds the edge of the liquid cooling plate body and covers the edge of the top surface of the battery stack, and the middle channel is located on the inner side of the edge water inlet channel and covers the middle of the top surface of the battery stack.

[0012] Optionally, the middle flow channel includes a plurality of branch flow channels, the inlet of each branch flow channel is connected to the edge water inlet flow channel, the outlet of each branch flow channel is connected to the water outlet converging flow channel, the inlets of the plurality of branch flow channels are arranged at intervals along the edge water inlet flow channel, and the outlets of the plurality of branch flow channels are arranged at intervals along the water outlet converging flow channel.

[0013] Optionally, the battery module comprises a plurality of battery cells stacked along the front-rear direction of the vehicle, and a plurality of the branch flow channels extend along the front-rear direction of the vehicle;

[0014] The water inlet is connected to the front side of the liquid cooling plate body, the edge water inlet channel is divided into two by the water inlet position to form a left edge water inlet channel and a right edge water inlet channel, the rear sides of the left edge water inlet channel and the right edge water inlet channel are connected to the inlets of the plurality of branch channels, and the water outlet converging channel is located at the front side of the liquid cooling plate body and isolated from the edge water inlet channel;

[0015] After entering the water inlet, the coolant is divided into two and flows through the left edge water inlet channel and the right edge water inlet channel respectively, and merges at the rear side of the left edge water inlet channel and the right edge water inlet channel, and then flows into the water outlet converging channel through multiple branch channels, and then flows out from the water outlet.

[0016] Optionally, the battery pack further comprises a thermally conductive structural adhesive, a bottom structural adhesive and a tray, and the liquid cooling plate, the thermally conductive structural adhesive, the battery stack, the bottom structural adhesive and the tray are stacked in sequence from top to bottom;

[0017] The tray includes a square frame, a front anti-expansion beam arranged on the front frame of the square frame, and a rear anti-expansion beam arranged on the rear frame of the square frame. The front end face of the battery stack is separated from the front anti-expansion beam by a buffer layer capable of absorbing the expansion of the battery cells, and the rear end face of the battery stack is separated from the rear anti-expansion beam by a buffer layer capable of absorbing the expansion of the battery cells.

[0018] Optionally, the thermally conductive structural adhesive includes a front-end structural adhesive and a back-end high thermal conductivity structural adhesive arranged in front and back, the front-end structural adhesive and the back-end high thermal conductivity structural adhesive are bonded between the top surface of the battery stack and the bottom surface of the liquid cooling plate body, and the thermal conductivity coefficient of the front-end structural adhesive is smaller than the thermal conductivity coefficient of the back-end high thermal conductivity structural adhesive.

[0019] Optionally, the battery module comprises a plurality of battery cells stacked along the left-right direction of the vehicle, and a plurality of the branch flow channels extend along the left-right direction of the vehicle;

[0020] The water inlet is connected to the front side of the liquid cooling plate body, the edge water inlet channel is divided into two by the water inlet position to form a left edge water inlet channel and a right edge water inlet channel, the left section of the left edge water inlet channel is connected to the inlets of the plurality of branch channels on the left, the right section of the right edge water inlet channel is connected to the inlets of the plurality of branch channels on the right, the water outlet converging channel is located in the middle position of the front-rear direction of the liquid cooling plate body and is isolated from the edge water inlet channel;

[0021] After entering from the water inlet, the coolant is divided into two and flows through the left edge water inlet channel and the right edge water inlet channel respectively, flows into the water outlet converging channel through the multiple branch channels on the left and right sides, and then flows out from the water outlet.

[0022] Optionally, the branch flow channel is tortuous, and the water outlet converging flow channel is divided into a left water outlet converging flow channel and a right water outlet converging flow channel by a rib plate, the outlets of multiple branch flow channels on the left side are connected to the left water outlet converging flow channel, and the outlets of multiple branch flow channels on the right side are connected to the right water outlet converging flow channel, and the left water outlet converging flow channel and the right water outlet converging flow channel are connected to the water outlet after merging on the front side of the liquid cooling plate body.

[0023] Optionally, the battery pack further comprises a thermally conductive structural adhesive, a bottom structural adhesive and a tray, and the liquid cooling plate, the thermally conductive structural adhesive, the battery stack, the bottom structural adhesive and the tray are stacked in sequence from top to bottom;

[0024] The tray includes a square frame, and the left end face of the battery stack is separated from the inner wall of the left frame of the square frame by a buffer layer capable of absorbing the expansion of the battery cells, and the right end face of the battery stack is separated from the inner wall of the right frame of the square frame by a buffer layer capable of absorbing the expansion of the battery cells.

[0025] Optionally, the thermally conductive structural adhesive includes a left-side high thermal conductivity structural adhesive, a middle low thermal conductivity structural adhesive and a right-side high thermal conductivity structural adhesive arranged in sequence from left to right, the left-side high thermal conductivity structural adhesive, the middle low thermal conductivity structural adhesive and the right-side high thermal conductivity structural adhesive are bonded between the top surface of the battery stack and the bottom surface of the liquid cooling plate body, and the thermal conductivity coefficient of the middle low thermal conductivity structural adhesive is smaller than the thermal conductivity coefficient of the left-side high thermal conductivity structural adhesive and the right-side high thermal conductivity structural adhesive.

[0026] Optionally, the battery pack further includes a heat-insulating layer covering the outer surface of the tray.

[0027] Optionally, the coating area of ​​the bottom structural adhesive is not larger than the bottom area of ​​the battery stack;

[0028] The bottom structural adhesive comprises a plurality of structural adhesive strips spaced apart from each other.

[0029] According to the battery pack of an embodiment of the present invention, a liquid cooling circuit is arranged in the liquid cooling plate body, and the liquid cooling circuit includes an edge water inlet channel, a water outlet collecting channel, and an intermediate channel connected between the edge water inlet channel and the water outlet collecting channel. The edge water inlet channel surrounds the edge of the liquid cooling plate body and covers the edge of the top surface of the battery stack. The intermediate channel is located on the inner side of the edge water inlet channel and covers the middle of the top surface of the battery stack. In this way, the coolant enters from the edge of the liquid cooling plate, first flows through the edge area of ​​the battery stack, and then returns from the water outlet collecting channel after being diverted by the intermediate channel. The edge area of ​​the liquid cooling plate has a higher flow rate and stronger heating capacity. Under low temperature conditions, the heating requirements of different areas can be matched, and more heat can be given to the edge area of ​​the battery pack to balance the heat loss and control the temperature difference of the battery pack.

[0030] On the other hand, an embodiment of the present invention provides a vehicle including the above-mentioned battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is an exploded view of an existing battery pack;

[0032] Figure 2 is an exploded view of a battery pack provided in a first embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of a liquid cooling plate of a battery pack provided by a first embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of the distribution of the thermally conductive structural adhesive of the battery pack provided by the first embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of a thermally conductive structural adhesive for a battery pack provided by a first embodiment of the present invention;

[0036] Figure 6 is a schematic diagram of a liquid cooling plate of a battery pack provided in a second embodiment of the present invention;

[0037] Figure 7 is a schematic diagram of the distribution of the thermally conductive structural adhesive of the battery pack provided by the second embodiment of the present invention;

[0038] Figure 8 is a schematic diagram of a thermally conductive structural adhesive for a battery pack provided by a second embodiment of the present invention;

[0039] Fig. 9 Schematic diagram of the bottom structural adhesive of the battery pack provided in an embodiment of the present invention.

[0040] The reference numerals in the specification are as follows:

[0041] 1. Liquid cooling plate; 11. Liquid cooling plate body; 111. Edge water inlet channel; 1111. Left edge water inlet channel; 1112. Right edge water inlet channel; 112. Outlet collecting channel; 1121. Left outlet collecting channel; 1122. Right outlet collecting channel; 113. Middle channel; 1131. Branch channel; 11311. Inlet; 11312. Outlet; 12. Water inlet; 13. Water outlet; 14. Rib plate;

[0042] 2. Thermally conductive structural adhesive; 21. Structural adhesive at the front end of the process; 22. High thermally conductive structural adhesive at the back end of the process; 23. High thermally conductive structural adhesive on the left; 24. Low thermally conductive structural adhesive in the middle; 25. High thermally conductive structural adhesive on the right;

[0043] 3. Battery stack; 31. Battery module; 311. Battery cell;

[0044] 4. Bottom structural adhesive; 41. Structural adhesive strip;

[0045] 5. Tray; 51. Square frame; 52. Front anti-expansion beam; 53. Rear anti-expansion beam;

[0046] 6. Insulation layer. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0048] First embodiment

[0049] like Figures 2 to 5 As shown, the battery pack provided by the first embodiment of the present invention includes a liquid cooling plate 1, a thermal conductive structural adhesive 2, a battery stack 3, a bottom structural adhesive 4 and a tray 5 stacked in sequence from top to bottom, the battery stack 3 includes at least one battery module 31, and the battery module 31 includes a plurality of battery cells 311 stacked along the front and rear direction of the vehicle.

[0050] The liquid cooling plate 1 is preferably a stamped brazed liquid cooling plate.

[0051] The liquid cooling plate 1 includes a liquid cooling plate body 11, a water inlet 12 and a water outlet 13. A liquid cooling circuit is arranged in the liquid cooling plate body 11. The liquid cooling circuit includes an edge water inlet channel 111, a water outlet collecting channel 112 and an intermediate channel 113 connected between the edge water inlet channel 111 and the water outlet collecting channel 112. The water inlet 12 is connected to the liquid cooling plate body 11 and is connected to the edge water inlet channel 111. The water outlet 13 is connected to the liquid cooling plate body 11 and is connected to the water outlet collecting channel 112.

[0052] The edge water inlet channel 111 surrounds the edge of the liquid cooling plate body 1 and covers the top edge of the battery stack 3 , and the middle channel 113 is located inside the edge water inlet channel 111 and covers the middle of the top of the battery stack 3 .

[0053] The middle flow channel 113 includes a plurality of branch flow channels 1131, an inlet 11311 of each branch flow channel 1131 is connected to the edge water inlet flow channel 111, an outlet 11312 of each branch flow channel 1131 is connected to the water outlet converging flow channel 112, a plurality of inlets 11312 of the branch flow channels 1131 are arranged at intervals along the edge water inlet flow channel 111, and a plurality of outlets 11312 of the branch flow channels 1131 are arranged at intervals along the water outlet converging flow channel 112.

[0054] The number of the battery modules 31 and the number of the battery cells 311 in each battery module 31 are set according to the voltage and current requirements. Preferably, only one battery module 31 is used, so that the assembly space between multiple battery modules 31 can be reduced to stack more battery cells 311, thereby increasing the energy density per unit volume of the battery pack and increasing the vehicle's endurance.

[0055] The battery cell 311 is a square thin-film battery cell, i.e., a blade battery. The length of a blade battery is much greater than its width, and its thickness is much less than its width. The blade battery can maximize the space in the battery pack. The blade battery stacking structure has a high strength, and the reinforcing beam structure at the bottom of the tray 5 can be omitted, further improving the energy density per unit volume of the battery pack and increasing the vehicle's endurance.

[0056] In this embodiment, the front and rear and left and right directions of the vehicle refer to Figure 3 , Figure 4 direction sign.

[0057] In this embodiment, the branch flow channel 1131 extends along the front-rear direction of the vehicle, that is, the branch flow channel 1131 is perpendicular to the battery cell 311. Preferably, the intervals between the plurality of branch flow channels 1131 are the same, so as to improve the temperature balance of the battery pack.

[0058] The water inlet 12 is connected to the front side of the liquid cooling plate body 1, and the edge water inlet channel 111 is divided into two by the position of the water inlet 12 to form a left edge water inlet channel 1111 and a right edge water inlet channel 1112. The rear sides of the left edge water inlet channel 1111 and the right edge water inlet channel 1112 are connected to the inlets 11311 of the plurality of branch channels 1131, and the water outlet converging channel 112 is located at the front side of the liquid cooling plate body 1 and isolated from the edge water inlet channel 111. That is, the edge water inlet channel 111 and the water outlet converging channel 112 are located on the same side of the liquid cooling plate body 1, but are not directly connected to each other, but are connected through the plurality of branch channels 1131.

[0059] The edge area of ​​the liquid cooling plate 1 is preferentially allocated with flow, and the main circuit of the liquid cooling plate 1 is fed with water from the edge area, that is, the coolant enters from the water inlet 12 and is divided into two parts, respectively flowing through the left edge water inlet channel 1111 and the right edge water inlet channel 1112, and merges at the rear of the left edge water inlet channel 1111 and the right edge water inlet channel 1112, and then flows into the water outlet converging channel 112 through a plurality of the branch channels 1131, and then flows out from the water outlet 13. Since the edge water inlet channel 111 surrounds the edge of the liquid cooling plate body 1 and covers the top edge of the battery stack 3, the liquid cooling plate 1 can preferentially heat (or cool) the edge area of ​​the battery stack 3.

[0060] Figure 3 The number of the middle branch flow channels 1131 is 6, however, other numbers may be set according to the size of the battery stack.

[0061] The tray 5 includes a square frame 51, a front anti-expansion beam 52 arranged on the front side frame of the square frame 51, and a rear anti-expansion beam 53 arranged on the rear side frame of the square frame 51. The front end face of the battery stack 3 is separated from the front anti-expansion beam 52 by a buffer layer capable of absorbing the expansion of the battery cell, and the rear end face of the battery stack 3 is separated from the rear anti-expansion beam 53 by a buffer layer capable of absorbing the expansion of the battery cell. The buffer layer can be, for example, an aerogel or a plastic gasket. The buffer layer can absorb the expansion of the battery cell and can partially reduce the heat transfer between the battery stack 3 and the tray 5.

[0062] The front anti-expansion beam 52 and the rear anti-expansion beam 53 are respectively separated from the large surfaces of the first and last battery cells 311 of the battery stack 3 by a buffer layer (the buffer layer is not shown in the figure), which plays a role in suppressing the expansion of the battery pack. The main mass of the tray 5 is concentrated on the square frame 51. The battery cells 311 generate heat loss to the environment through the tray 5. While increasing the temperature of the battery pack, it is also necessary to increase the temperature of the square frame 51 of the tray 5, especially the presence of the front anti-expansion beam 52 and the rear anti-expansion beam 53, which needs to absorb more heat. Through the above analysis, the battery cells 311 with the front anti-expansion beam 52 and the rear anti-expansion beam 53 have greater heat loss and lower temperature. In order to balance the temperature difference, more heat needs to be given to the battery cells 311 on the front and rear sides.

[0063] like Figure 4 and Figure 5 As shown, the thermally conductive structural adhesive 2 includes a front-end structural adhesive 21 and a back-end high thermal conductive structural adhesive 22 arranged front and back, the front-end structural adhesive 21 and the back-end high thermal conductive structural adhesive 22 are glued between the top surface of the battery stack 3 and the bottom surface of the liquid cooling plate body 11, and the thermal conductivity of the front-end structural adhesive 21 is less than the thermal conductivity of the back-end high thermal conductive structural adhesive 22. That is, the front-end structural adhesive 21 is non-thermal conductive or has low thermal conductivity.

[0064] like Figure 4 As shown, the left and right sides of the battery stack 3 are the priority flow areas of the liquid cooling circuit, which have strong heating capabilities. The second section of the battery cell 311 is the return section of the liquid cooling circuit, where the water temperature and flow rate are low and the heating capacity is weak. In order to avoid excessive heat exchange in the front section of the liquid cooling circuit, the top surface of the battery stack 3 corresponds to the front section of the liquid cooling circuit and is coated with black structural glue (process front section structural glue 21). In order to improve the heat exchange capacity of the rear section of the liquid cooling circuit, the rear section of the liquid cooling circuit is coated with high thermal conductivity thermal conductive structural glue (process rear section high thermal conductive structural glue 22). Apply thermal conductive structural glue with different thermal conductivity coefficients in different regions, and apply glue differently in the edge area and the center area. Control according to the needs of thermal management is conducive to controlling the temperature difference of the battery pack.

[0065] In addition, the battery pack also includes a heat preservation layer 6 covering the outer surface of the tray 5. Specifically, the heat preservation layer 6 covers the outer surface of the square frame 51 of the tray 5. The application of the external heat preservation layer 6 integrates the original internal heat preservation layer to the outside of the tray 5, and increases the temperature of the edge area of ​​the battery stack 3 by increasing the temperature of the tray 5. The thickness and specific fixing area of ​​the heat preservation layer 6 depend on the space of the whole vehicle and the heat preservation requirements.

[0066] In addition, the coating area of ​​the bottom structural adhesive 4 is not larger than the bottom area of ​​the battery stack 3. That is, the fixing method of the battery cell 311 and the tray 5 by not completely coating the structural adhesive can reduce the heat exchange between the battery cell 311 and the tray by reducing the coating area of ​​the bottom structural adhesive 4, thereby increasing the temperature of the battery cell 311.

[0067] For example, Fig. 9 As shown, the bottom structural adhesive 4 includes a plurality of mutually spaced structural adhesive strips 41. The shape, quantity, area and arrangement of the structural adhesive strips 41 can be adjusted as required.

[0068] According to the battery pack of the first embodiment of the present invention, the coolant enters from the edge of the liquid cooling plate 1, flows through the edge area of ​​the battery stack 3, and returns from the outlet and collection channel 112 after being diverted through the intermediate flow channel 113. The edge area of ​​the liquid cooling plate 1 has a higher flow rate and stronger heating capacity. Under low temperature conditions, the heating requirements of different areas can be matched, and more heat can be given to the edge area of ​​the battery pack to balance the heat loss and control the temperature difference of the battery pack.

[0069] In addition, relative to Figure 1 The prior art shown in the figure eliminates the sealing cover and the fireproof and heat-insulating cotton, reduces the number of parts, makes the parts flatter and more regular, improves the space utilization, and helps to reduce the cost.

[0070] In addition, in terms of thermal management effect, the coolant enters from the edge of the liquid cooling plate, flows through the edge area of ​​the battery stack first, and then returns from the outlet collecting channel after being diverted through the middle flow channel. The edge area of ​​the liquid cooling plate has a higher flow rate and stronger heating capacity, which distinguishes the difference in heat load between the edge and middle areas of the battery pack, which is beneficial to managing the temperature difference of the battery and improving the low-temperature performance of the battery.

[0071] In addition, in terms of design, the liquid cooling circuit layout of the liquid cooling plate and the different layouts of the thermal conductive structural adhesive make the battery pack of the present application have more flexible temperature regulation means, which can better control the temperature difference of the battery.

[0072] Second embodiment

[0073] like Figures 6 to 8As shown, the battery pack provided by the second embodiment of the present invention is different from that of the first embodiment in that the battery module 31 includes a plurality of battery cells 311 stacked along the left-right direction of the vehicle.

[0074] In this embodiment, the front and rear and left and right directions of the vehicle refer to Figure 6 , Figure 7 direction sign.

[0075] In this embodiment, the plurality of branch flow channels 1131 extend along the left-right direction of the vehicle. That is, the branch flow channels 1131 are perpendicular to the battery cells 311. Preferably, the plurality of branch flow channels 1131 are spaced at the same intervals to improve the temperature balance of the battery pack.

[0076] The water inlet 12 is connected to the front side of the liquid cooling plate body 11, and the edge water inlet channel 111 is divided into two parts by the position of the water inlet 12 to form a left edge water inlet channel 1111 and a right edge water inlet channel 1112. The left section of the left edge water inlet channel 1111 is connected to the inlet 11311 of the plurality of branch channels 1131 on the left side, and the right section of the right edge water inlet channel 1112 is connected to the inlet 11311 of the plurality of branch channels 1131 on the right side. The water outlet converging channel 112 is located in the middle position of the front-to-back direction of the liquid cooling plate body 11 and is isolated from the edge water inlet channel 111. That is, the edge water inlet channel 111 and the water outlet converging channel 112 are not directly connected to each other, but are connected through the plurality of branch channels 1131.

[0077] The edge area of ​​the liquid cooling plate 1 is preferentially allocated with flow, and the main circuit of the liquid cooling plate 1 takes in water from the edge area. After the coolant enters from the water inlet 12, it is divided into two and flows through the left edge water inlet channel 1111 and the right edge water inlet channel 1112 respectively, and then flows into the water outlet converging channel 12 through the multiple branch channels 1131 on the left and right sides, and then flows out from the water outlet 13.

[0078] The branch channel 1131 is in a tortuous shape, such as a Z-shape, a W-shape, an S-shape, etc. The tortuous branch channel 1131 can ensure that the temperature of the battery cell 311 is uniform, and at the same time ensure that the coolant returns from the middle area.

[0079] like Figure 6 As shown, there are 5 branch channels 1131 on the left and right sides, however, according to different requirements, other numbers of branch channels 1131 may be provided. Moreover, in some embodiments, the branch channels 1131 on the left and right sides do not need to be completely symmetrical, and the shapes and numbers may be different.

[0080] like Figure 6As shown, the water outlet collecting channel 112 is divided into a left water outlet collecting channel 1121 and a right water outlet collecting channel 1122 by a rib plate 14, the outlets 11312 of the multiple branch channels 1131 on the left are connected to the left water outlet collecting channel 1121, and the outlets 11312 of the multiple branch channels 1131 on the right are connected to the right water outlet collecting channel 1122, and the left water outlet collecting channel 1121 and the right water outlet collecting channel 1122 are connected to the water outlet 13 after merging at the front side of the liquid cooling plate body 1.

[0081] For the stamped brazed liquid cooling plate, the welding surface of the stamped brazed liquid cooling plate divides the liquid cooling circuit to form an edge water inlet channel 111, a water outlet converging channel 112, and an intermediate channel 113 connected between the edge water inlet channel 111 and the water outlet converging channel 112. The rib plate 14 is a part of the welding surface.

[0082] In the second embodiment, the tray 5 includes a square frame 51, and the left end face of the battery stack 3 is separated from the inner wall of the left frame of the square frame 51 by a buffer layer that can absorb the expansion of the battery cell, and the right end face of the battery stack 3 is separated from the inner wall of the right frame of the square frame 51 by a buffer layer that can absorb the expansion of the battery cell. The buffer layer can be, for example, an aerogel or a plastic gasket. The buffer layer can absorb the expansion of the battery cell and can partially reduce the heat transfer between the battery stack 3 and the tray 5. That is, in the second embodiment, the left and right side frames of the tray 5 act as anti-expansion beams, which play a role in suppressing the expansion of the battery. The main mass of the tray 5 is also concentrated on the square frame 51. The battery cell 311 generates heat loss to the environment through the tray 5. While increasing the temperature of the battery pack, it is also necessary to increase the temperature of the square frame 51 of the tray 5.

[0083] Different from the first embodiment, in the second embodiment, the height of the square frame 51 of the tray 5 is significantly higher than that of the first embodiment, and more heating is required. The battery cells 311 on the left and right sides have greater heat loss and lower temperature. In order to balance the temperature difference, more heat needs to be given to the battery cells 311 on the left and right sides.

[0084] like Figure 7 and Figure 8 As shown, the thermally conductive structural adhesive 2 includes a left high thermal conductive structural adhesive 23, a middle low thermal conductive structural adhesive 24 and a right high thermal conductive structural adhesive 25 arranged from left to right, the left high thermal conductive structural adhesive 23, the middle low thermal conductive structural adhesive 24 and the right high thermal conductive structural adhesive 25 are glued between the top surface of the battery stack 3 and the bottom surface of the liquid cooling plate body 11, and the thermal conductivity of the middle low thermal conductive structural adhesive 24 is less than the thermal conductivity of the left high thermal conductive structural adhesive 23 and the right high thermal conductive structural adhesive 25. Preferably, the thermal conductivity of the left high thermal conductive structural adhesive 23 is the same as that of the right high thermal conductive structural adhesive 25, and the coating shape and area are consistent.

[0085] That is, in the second embodiment, the left and right edge areas of the battery stack 3 are coated with a thermally conductive structural glue with a high thermal conductivity coefficient (the high thermal conductive structural glue 23 on the left and the high thermal conductive structural glue 25 on the right), and the remaining areas are coated with a thermally conductive structural glue with a low thermal conductivity coefficient (the low thermal conductive structural glue 24 in the middle). Compared with the first embodiment, the difference mainly lies in the design of the liquid cooling circuit and the difference in heat loss. There is a diversion in the process of the liquid cooling circuit flowing along the edge area, and the heating capacity is slightly weaker than that of the first embodiment. However, the arrangement of the thermally conductive structural glue 2 in the second embodiment makes the heat loss at the edge of the battery pack stronger than that in the first embodiment, so it is necessary to strengthen the heat exchange in the edge area, that is, to apply a thermally conductive structural glue with a higher thermal conductivity coefficient to the edge.

[0086] According to the battery pack of the second embodiment of the present invention, the coolant enters from the edge of the liquid cooling plate 1, flows through the edge area of ​​the battery stack 3, and returns from the outlet and collection channel 112 after being diverted through the intermediate flow channel 113. The edge area of ​​the liquid cooling plate 1 has a higher flow rate and stronger heating capacity. Under low temperature conditions, the heating requirements of different areas can be matched, and more heat can be given to the edge area of ​​the battery pack to balance the heat loss and control the temperature difference of the battery pack.

[0087] In addition, relative to Figure 1 The prior art shown in the figure eliminates the sealing cover and the fireproof and heat-insulating cotton, reduces the number of parts, makes the parts flatter and more regular, improves the space utilization, and helps to reduce the cost.

[0088] In addition, in terms of thermal management effect, the coolant enters from the edge of the liquid cooling plate, flows through the edge area of ​​the battery stack first, and then returns from the outlet collecting channel after being diverted through the middle flow channel. The edge area of ​​the liquid cooling plate has a higher flow rate and stronger heating capacity, which distinguishes the difference in heat load between the edge and middle areas of the battery pack, which is beneficial to managing the temperature difference of the battery and improving the low-temperature performance of the battery.

[0089] In addition, in terms of design, the liquid cooling circuit layout of the liquid cooling plate and the different layouts of the thermal conductive structural adhesive make the battery pack of the present application have more flexible temperature regulation means, which can better control the temperature difference of the battery.

[0090] In addition, an embodiment of the present invention provides a vehicle, comprising the battery pack of the above embodiment.

[0091] The vehicle may be a hybrid vehicle or a pure electric vehicle.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: It includes a liquid cooling plate and a battery stack, wherein the battery stack includes at least one battery module; The liquid cooling plate comprises a liquid cooling plate body, a water inlet and a water outlet, a liquid cooling circuit is arranged in the liquid cooling plate body, the liquid cooling circuit comprises an edge water inlet flow channel, a water outlet collection flow channel and an intermediate flow channel connected between the edge water inlet flow channel and the water outlet collection flow channel, the water inlet is connected to the liquid cooling plate body and communicates with the edge water inlet flow channel, the water outlet is connected to the liquid cooling plate body and communicates with the water outlet collection flow channel; The edge water inlet channel surrounds the edge of the liquid cooling plate body and covers the edge of the top surface of the battery stack, and the middle channel is located inside the edge water inlet channel and covers the middle of the top surface of the battery stack; The coolant enters from the edge of the liquid cooling plate, flows through the edge area of ​​the battery stack, is diverted through the middle flow channel, and then returns to the water outlet and collection channel.

2. The battery pack according to claim 1, characterized in that: The middle flow channel includes a plurality of branch flow channels, the inlet of each branch flow channel is connected to the edge water inlet flow channel, the outlet of each branch flow channel is connected to the water outlet converging flow channel, the inlets of the plurality of branch flow channels are arranged at intervals along the edge water inlet flow channel, and the outlets of the plurality of branch flow channels are arranged at intervals along the water outlet converging flow channel.

3. The battery pack according to claim 2, characterized in that: The battery module includes a plurality of battery cells stacked along the front-rear direction of the vehicle, and a plurality of branch flow channels extend along the front-rear direction of the vehicle; The water inlet is connected to the front side of the liquid cooling plate body, the edge water inlet channel is divided into two by the water inlet position to form a left edge water inlet channel and a right edge water inlet channel, the rear sides of the left edge water inlet channel and the right edge water inlet channel are connected to the inlets of the plurality of branch channels, and the water outlet converging channel is located at the front side of the liquid cooling plate body and isolated from the edge water inlet channel; After entering the water inlet, the coolant is divided into two and flows through the left edge water inlet channel and the right edge water inlet channel respectively, and merges at the rear side of the left edge water inlet channel and the right edge water inlet channel, and then flows into the water outlet converging channel through multiple branch channels, and then flows out from the water outlet.

4. The battery pack according to claim 1, characterized in that: The battery pack further comprises a thermally conductive structural adhesive, a bottom structural adhesive and a tray, wherein the liquid cooling plate, the thermally conductive structural adhesive, the battery stack, the bottom structural adhesive and the tray are stacked in order from top to bottom; The tray includes a square frame, a front anti-expansion beam arranged on the front frame of the square frame, and a rear anti-expansion beam arranged on the rear frame of the square frame. The front end face of the battery stack is separated from the front anti-expansion beam by a buffer layer capable of absorbing the expansion of the battery cells, and the rear end face of the battery stack is separated from the rear anti-expansion beam by a buffer layer capable of absorbing the expansion of the battery cells.

5. The battery pack according to claim 4, characterized in that: The thermally conductive structural adhesive includes a front-end structural adhesive and a back-end high thermal conductivity structural adhesive arranged front and back, the front-end structural adhesive and the back-end high thermal conductivity structural adhesive are bonded between the top surface of the battery stack and the bottom surface of the liquid cooling plate body, and the thermal conductivity coefficient of the front-end structural adhesive is smaller than the thermal conductivity coefficient of the back-end high thermal conductivity structural adhesive.

6. The battery pack according to claim 2, characterized in that: The battery module includes a plurality of battery cells stacked along the left-right direction of the vehicle, and a plurality of branch flow channels extend along the left-right direction of the vehicle; The water inlet is connected to the front side of the liquid cooling plate body, the edge water inlet channel is divided into two by the water inlet position to form a left edge water inlet channel and a right edge water inlet channel, the left section of the left edge water inlet channel is connected to the inlets of the plurality of branch channels on the left, the right section of the right edge water inlet channel is connected to the inlets of the plurality of branch channels on the right, the water outlet converging channel is located in the middle position of the front-rear direction of the liquid cooling plate body and is isolated from the edge water inlet channel; After entering from the water inlet, the coolant is divided into two and flows through the left edge water inlet channel and the right edge water inlet channel respectively, flows into the water outlet converging channel through the multiple branch channels on the left and right sides, and then flows out from the water outlet.

7. The battery pack according to claim 6, characterized in that: The branch flow channel is circuitous, and the water outlet and collecting flow channel is divided into a left water outlet and collecting flow channel and a right water outlet and collecting flow channel by a rib plate. The outlets of the multiple branch flow channels on the left are connected to the left water outlet and collecting flow channel, and the outlets of the multiple branch flow channels on the right are connected to the right water outlet and collecting flow channel. The left water outlet and collecting flow channel and the right water outlet and collecting flow channel are connected to the water outlet after merging on the front side of the liquid cooling plate body.

8. The battery pack according to claim 1, characterized in that: The battery pack further comprises a thermally conductive structural adhesive, a bottom structural adhesive and a tray, wherein the liquid cooling plate, the thermally conductive structural adhesive, the battery stack, the bottom structural adhesive and the tray are stacked in order from top to bottom; The tray includes a square frame, and the left end face of the battery stack is separated from the inner wall of the left frame of the square frame by a buffer layer capable of absorbing the expansion of the battery cells, and the right end face of the battery stack is separated from the inner wall of the right frame of the square frame by a buffer layer capable of absorbing the expansion of the battery cells.

9. The battery pack according to claim 8, characterized in that: The thermally conductive structural adhesive includes a left-side high thermal conductivity structural adhesive, a middle low thermal conductivity structural adhesive and a right-side high thermal conductivity structural adhesive arranged from left to right in sequence, the left-side high thermal conductivity structural adhesive, the middle low thermal conductivity structural adhesive and the right-side high thermal conductivity structural adhesive are bonded between the top surface of the battery stack and the bottom surface of the liquid cooling plate body, and the thermal conductivity coefficient of the middle low thermal conductivity structural adhesive is smaller than the thermal conductivity coefficient of the left-side high thermal conductivity structural adhesive and the right-side high thermal conductivity structural adhesive.

10. The battery pack according to claim 4, 5, 8 or 9, characterized in that: The battery pack also includes a heat-insulating layer covering the outer surface of the tray.

11. The battery pack according to claim 4, 5, 8 or 9, characterized in that: The coating area of ​​the bottom structural adhesive is not larger than the bottom area of ​​the battery stack; The bottom structural adhesive comprises a plurality of structural adhesive strips spaced apart from each other.

12. A vehicle, characterized in that: A battery pack comprising any one of claims 1-11.

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