Battery pack and battery pack manufacturing method

Abstract

The invention belongs to the technical field of power batteries, and discloses a battery pack and a battery pack manufacturing method. The battery pack specifically comprises a first liquid cooling plate, a plurality of battery cell groups arranged at intervals along a first direction and a plurality of second liquid cooling plates extending along a second direction, each battery cell group comprises a plurality of single battery cells stacked along the second direction, and the second direction is perpendicular to the first direction; the first liquid cooling plate is arranged at the bottoms of the battery cell groups and is used for bearing the battery cell groups; the second bottom wall of the second liquid cooling plate is communicated with the first liquid cooling plate, and the second liquid cooling plate is attached to at least one of the two first side walls at the two ends of each battery cell group along the first direction, so that the single battery cells are respectively in heat exchange connection with the first liquid cooling plate and the second liquid cooling plate. According to the battery pack, the heat dissipation efficiency and the cooling effect can be improved, reliable and safe operation of the single battery cells is ensured, and the energy density of the battery pack can also be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a battery pack and a method for manufacturing the battery pack. Background Art

[0002] The range of a new energy vehicle (NEV) on a single charge primarily depends on the energy density of its battery system. To meet consumer demand for long-range NEVs, battery systems are designed and developed with high energy density. However, high-energy-density battery systems generate and accumulate more heat during operation. Failure to dissipate this heat in a timely manner to maintain the battery within an optimal temperature range can result in the battery system not being able to fully perform and, in severe cases, can lead to safety accidents.

[0003] In cylindrical battery systems, the traditional solution is to install liquid cooling plates and liquid cooling pipes in the battery system to dissipate heat from the batteries. The flow path of the coolant is "liquid inlet pipe at the side of the battery system (flowing in) - serpentine liquid cooling plate (passing) - liquid outlet pipe at the side of the battery system (flowing out)". Although this heat dissipation method is widely used, it still has defects. First, the coolant preferentially flows in from the side of the battery system for heat exchange. This heat dissipation method will cause the temperature in the center of the battery system to be higher than the two sides, resulting in poor temperature consistency of the batteries in the system, affecting the service life of the battery system; second, a certain amount of space is required in the side area of the battery system to place the liquid inlet and outlet pipes, which has a low internal space utilization rate of the battery system and has a negative impact on the improvement of the overall energy density of the battery system; third, the liquid cooling plates are connected by bellows expansion joints. The interface can withstand limited pressure (about 2Mpa). Long-term high working pressure service has a high risk of failure, causing coolant leakage and safety accidents.

[0004] Therefore, there is an urgent need to provide a new type of battery pack and a battery pack manufacturing method to solve the above technical problems in the prior art. Summary of the Invention

[0005] An object of the present invention is to provide a battery pack that can improve heat dissipation efficiency and cooling effect, ensure reliable and safe operation of single cells, and also improve the energy density of the battery pack.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The battery pack specifically includes a first liquid cooling plate, a plurality of battery cell groups spaced apart along a first direction, and a plurality of second liquid cooling plates extending along the second direction. The battery cell groups include a plurality of single battery cells stacked along the second direction, and the second direction is perpendicular to the first direction. The first liquid cooling plate is arranged at the bottom of the plurality of battery cell groups and is used to support the battery cell groups. The second bottom wall of the second liquid cooling plate is connected to the first liquid cooling plate, and at least one of the two first side walls at both ends of each battery cell group along the first direction is attached with the second liquid cooling plate, so that the single battery cells are respectively connected to the first liquid cooling plate and the second liquid cooling plate for heat exchange.

[0008] Optionally, a first liquid cooling channel is provided in the first liquid cooling plate, a second liquid cooling channel is provided in the second liquid cooling plate, and either the first top wall of the first liquid cooling plate or the second bottom wall of the second liquid cooling plate is provided with a first liquid inlet joint, one end of the first liquid inlet joint is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel; and / or either the first top wall of the first liquid cooling plate or the second bottom wall of the second liquid cooling plate is provided with a first liquid outlet joint, one end of the first liquid outlet joint is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel.

[0009] Optionally, the first top wall of the above-mentioned first liquid cooling plate is provided with multiple above-mentioned first liquid inlet joints and multiple above-mentioned first liquid outlet joints, multiple above-mentioned first liquid inlet joints are arranged at intervals along the above-mentioned first direction, multiple above-mentioned first liquid outlet joints are arranged at intervals along the above-mentioned first direction, and the above-mentioned first liquid inlet joints and the above-mentioned first liquid outlet joints are arranged at intervals in the above-mentioned second direction.

[0010] Optionally, the first liquid cooling plate is provided with the first liquid outlet joint at both ends along the second direction, the first liquid inlet joint is provided between the two first liquid outlet joints spaced apart along the second direction, and the two ends of the second liquid cooling plate along the second direction are connected one-to-one to the two first liquid outlet joints spaced apart along the second direction.

[0011] Optionally, N first liquid inlet connectors are arranged between two of the first liquid outlet connectors arranged at intervals along the second direction, and the middle of each of the second liquid cooling plates is connected to N first liquid inlet connectors, where N is an integer greater than 1.

[0012] Optionally, the second liquid cooling plates are provided at both ends of each of the battery cell groups along the first direction, and one second liquid cooling plate is sandwiched between two adjacent battery cell groups along the first direction.

[0013] Optionally, the single battery cell is a cylindrical battery cell, the second sidewalls of the second liquid cooling plate at both ends along the first direction are wavy, and the single battery cell is adapted to the second sidewalls of the second liquid cooling plate at both ends along the first direction.

[0014] Optionally, a plurality of the battery cell groups are stacked along the second direction, each of the battery cell groups is provided with a second liquid cooling plate, and the second liquid cooling plates provided to two adjacent battery cell groups along the second direction are staggered in the first direction.

[0015] Optionally, a plurality of fixing grooves are evenly spaced apart on the first top wall of the first liquid cooling plate, and the single battery cells are inserted into the fixing grooves one by one. A thermal conductive structural adhesive is sandwiched between the bottom wall of the single battery cell and the fixing groove, and between the circumferential side wall of the single battery cell and the second liquid cooling plate.

[0016] Optionally, the battery pack further comprises a bottom plate, which is spaced apart on the side of the first liquid cooling plate away from the second liquid cooling plate, an explosion-proof valve is provided on the bottom wall of the single cell, a pressure relief hole is provided on the inner bottom wall of the fixing groove through the first liquid cooling plate, a sealing sheet for blocking the pressure relief hole is provided in the pressure relief hole, and the explosion-proof valve is provided corresponding to the pressure relief hole; when the single cell is depressurized, the interior of the single cell can be connected to the pressure relief cavity between the first liquid cooling plate and the bottom plate.

[0017] Another object of the present invention is to provide a battery pack manufacturing method, which is used to manufacture a battery pack as described in any of the above-mentioned schemes, including the steps of: S1, manufacturing the above-mentioned first liquid cooling plate and the above-mentioned second liquid cooling plate; S2, connecting the second bottom walls of multiple above-mentioned second liquid cooling plates to the first top wall of the above-mentioned first liquid cooling plate, and the above-mentioned second liquid cooling plate is extended along the second direction; S3, placing single battery cells on the first top wall of the above-mentioned first liquid cooling plate, so that the above-mentioned single battery cells are stacked along the above-mentioned second direction to form a battery cell group, and at least one of the first side walls at both ends of the above-mentioned battery cell group along the above-mentioned first direction is attached to the second liquid cooling plate, and each of the above-mentioned single battery cells is connected to the above-mentioned first liquid cooling plate and the above-mentioned second liquid cooling plate for heat exchange.

[0018] Beneficial effects:

[0019] The battery pack of the present invention uses a first liquid cooling plate and a second liquid cooling plate to cool a cell group within the battery pack. The cell group comprises a plurality of individual cells stacked along a second direction. The first top wall of the first liquid cooling plate supports the individual cells, thereby cooling the bottom of the individual cells. The second liquid cooling plate is attached to the first side wall of at least one end of the cell group along the first direction, thereby cooling the circumferential side walls of the individual cells, achieving complete cooling of the individual cells. This provides improved cooling and heat dissipation, ensuring safe and reliable operation of the individual cells within the battery pack. Furthermore, the bottom of the second liquid cooling plate is directly connected to the first top wall of the first liquid cooling plate, eliminating the need for additional connecting pipes to connect the second liquid cooling plate to the battery pack's liquid cooling system. This simplifies the battery pack structure and production process steps, increases the space within the battery pack for installing individual cells, improves the battery pack's energy density, and enhances manufacturing efficiency and reduces manufacturing costs. This battery pack improves heat dissipation efficiency and cooling effectiveness, ensuring reliable and safe operation of the individual cells and increasing the battery pack's energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an axonometric view of a partial structure of a battery pack in Example 1 provided in a specific embodiment of the present invention;

[0021] Figure 2 is an axonometric view of a partial structure of a battery pack in Example 2 provided in a specific embodiment of the present invention;

[0022] Figure 3 is an axonometric diagram of a partial structure of a battery pack in Example 3 provided in a specific embodiment of the present invention;

[0023] Figure 4 This is an axonometric view of the first and second liquid cooling plates after installation in Example 1 provided in a specific embodiment of the present invention;

[0024] Figure 5 1 is an exploded view of the first liquid cooling plate and the second liquid cooling plate in Example 1 provided in a specific embodiment of the present invention;

[0025] Figure 6 is an exploded view of a partial structure of a battery pack in Example 1 provided in a specific embodiment of the present invention;

[0026] Figure 7 It is a cross-sectional view of a single battery cell and a portion of a first liquid cooling plate provided in a specific embodiment of the present invention.

[0027] In the picture:

[0028] 100, battery cell group; 101, first side wall; 110, single battery cell; 111, explosion-proof valve; 112, battery cell bottom wall; 120, thermally conductive structural adhesive;

[0029] 200, first liquid cooling plate; 201, liquid inlet manifold; 202, liquid outlet manifold; 203, first liquid inlet connector; 204, first liquid outlet connector; 205, first liquid cooling channel; 206, first top wall; 210, fixing groove; 211, pressure relief hole; 212, sealing sheet; 220, bottom plate; 221, pressure relief cavity;

[0030] 300, second liquid cooling plate; 301, second liquid cooling channel; 302, second bottom wall; 303, second side wall; 310, mounting protrusion. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0032] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0033] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0035] The first direction described in this embodiment is Figure 1The X direction shown in is the length direction of the second liquid cooling plate 300; the second direction is Figure 1 The Y direction shown in , that is, the thickness direction of the second liquid cooling plate 300 , the first direction and the second direction are perpendicular to each other, and both the first direction and the second direction are perpendicular to the vertical direction.

[0036] like Figures 1 to 3 As shown, the battery pack specifically includes a first liquid cooling plate 200, a plurality of battery cell groups 100 spaced apart along a first direction, and a plurality of second liquid cooling plates 300 extending along the second direction. The battery cell group 100 includes a plurality of single battery cells 110 stacked along the second direction, and the second direction is perpendicular to the first direction. The first liquid cooling plate 200 is arranged at the bottom of the plurality of battery cell groups 100 and is used to support the battery cell groups 100. The second bottom wall 302 of the second liquid cooling plate 300 is connected to the first liquid cooling plate 200, and at least one of the two first side walls 101 at both ends of each battery cell group 100 along the first direction is attached with the second liquid cooling plate 300, so that the single battery cell 110 is respectively connected to the first liquid cooling plate 200 and the second liquid cooling plate 300 for heat exchange.

[0037] The battery pack of this embodiment uses a first liquid cooling plate 200 and a second liquid cooling plate 300 to cool the battery cell group 100 in the battery pack. The battery cell group 100 is composed of a plurality of single battery cells 110 stacked along the second direction. The first top wall 206 of the first liquid cooling plate 200 is used to support the single battery cell 110 so as to cool the bottom of the single battery cell 110. The second liquid cooling plate 300 is attached to the first side wall 101 of at least one end of the battery cell group 100 along the first direction, thereby cooling the circumferential side wall of the single battery cell 110, thereby achieving the cooling of the single battery cell 110. 0, providing improved cooling and heat dissipation, ensuring the safe and reliable operation of the individual cells 110 within the battery pack. Furthermore, the bottom of the second liquid cooling plate 300 is directly connected to the first top wall 206 of the first liquid cooling plate 200, eliminating the need for additional connecting pipes to connect the second liquid cooling plate 300 to the battery pack's liquid cooling system. This simplifies the battery pack structure and production process, thereby increasing the space within the battery pack for installing the individual cells 110, improving the battery pack's energy density, and enhancing manufacturing efficiency and reducing manufacturing costs. This battery pack improves heat dissipation efficiency and cooling effectiveness, ensuring the reliable and safe operation of the individual cells 110 and increasing the battery pack's energy density.

[0038] The single battery cell 110 in this embodiment is a large cylindrical battery of the 46XXX series, which will not be described in detail here.

[0039] The first top wall 206 of the first liquid cooling plate 200 described here is the outer wall of the first liquid cooling plate 200 close to the second liquid cooling plate 300 along its own thickness direction, and the first top wall 206 corresponds to the bottom wall of the first liquid cooling plate 200; the second bottom wall 302 of the second liquid cooling plate 300 is the outer wall of the second liquid cooling plate 300 close to the first liquid cooling plate 200 along its own height direction, and the second bottom wall 302 corresponds to the top wall of the second liquid cooling plate 300; wherein, the first top wall 206 and the second bottom wall 302 are arranged opposite to each other and abut against each other to achieve a fixed connection between the first liquid cooling plate 200 and the second liquid cooling plate 300.

[0040] Furthermore, a first liquid cooling channel is provided in the first liquid cooling plate 200, a second liquid cooling channel is provided in the second liquid cooling plate 300, and either the first top wall 206 of the first liquid cooling plate 200 or the second bottom wall 302 of the second liquid cooling plate 300 is provided with a first liquid inlet joint 203, one end of the first liquid inlet joint 203 is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel; and / or either the first top wall 206 of the first liquid cooling plate 200 or the bottom of the second liquid cooling plate 300 is provided with a first liquid outlet joint 204, one end of the first liquid outlet joint 204 is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel. In this embodiment, the first liquid inlet connector 203 and the first liquid outlet connector 204 are both pagoda connectors. A pagoda connector is a mechanical component used to connect two cylindrical parts. It is usually composed of two parts: a conical large end and a conical small end. The two parts can be fixed together by threads or other sealing devices after docking. Specifically, the ends of the pagoda connector in this embodiment are fixed to the first liquid cooling plate 200 and the second liquid cooling plate 300 by expansion joints. The pagoda connector mainly consists of a connector body, bolts, and a sealing ring. Its structure is simple, compact, easy to install, and suitable for various pipe connection situations. The material of the pagoda connector is usually stainless steel, carbon steel, copper, etc. The specific material selection should be determined according to the corrosiveness, oxidizing properties, etc. of the liquid or gas being transported. In this embodiment, the first liquid inlet connector 203 and the first liquid outlet connector 204 are made of stainless steel and fixed to the alloy first liquid cooling plate 200 by quick plugging, thereby achieving a quick connection between the first liquid cooling plate 200 and the second liquid cooling plate 300, while also improving the connection stability.

[0041] It should be noted that in order to improve the stability of the connection, sealing and reinforcement can be achieved by applying a filling thermal conductive structural adhesive 120 at the connection between the first liquid inlet joint 203 and the first liquid outlet joint 204 and the first liquid cooling plate 200 and the second liquid cooling plate 300 respectively, which will not be repeated here.

[0042] Specifically, a liquid inlet and a liquid outlet are provided at one end of the first top wall 206 of the first liquid cooling plate 200 along the first direction. The liquid inlet and the liquid outlet are respectively connected to the liquid inlet main pipe 201 and the liquid outlet main pipe 202 through CQC connectors (China Quality Certification Center). The CQC connector is a quick connector used for water pipe connection or water cooling system, usually made of metal or plastic, and has various models such as straight head, elbow and tee, which are suitable for different installation requirements.

[0043] Preferably, the height of the second liquid cooling plate 300 is 80 mm, the total thickness is 3.5 mm, the wall thickness is 0.3 mm, the channel reinforcement rib thickness of the second liquid cooling channel is 0.3 mm, and the second liquid cooling channel is serpentine. Each serpentine channel has the same cross-sectional size and good flow uniformity. The shape is a rounded rectangle with low flow resistance. At the same time, it has a certain mechanical strength to avoid deformation caused by squeezing the channel.

[0044] like Figure 4 and Figure 5 As shown, optionally, the first top wall 206 of the first liquid cooling plate 200 is provided with a plurality of the first liquid inlet joints 203 and a plurality of the first liquid outlet joints 204. The plurality of the first liquid inlet joints 203 are spaced apart along the first direction, the plurality of the first liquid outlet joints 204 are spaced apart along the first direction, and the first liquid inlet joints 203 and the first liquid outlet joints 204 are spaced apart in the second direction. In this embodiment, by providing the first liquid inlet joint 203 and the first liquid outlet joint 204 on the first liquid cooling plate 200, the first liquid inlet joint 203 and the second liquid outlet joint can be easily installed. After installation is completed, the second liquid cooling plate 300 can also be easily installed, thereby improving installation efficiency.

[0045] In this embodiment, the first liquid cooling plate 200 is provided with the first liquid outlet connector 204 at both ends along the second direction. The first liquid inlet connector 203 is provided between the two first liquid outlet connectors 204 spaced apart along the second direction. The second liquid cooling plate 300 is connected to the two first liquid outlet connectors 204 spaced apart along the second direction at both ends along the second direction. Thus, after flowing into the first liquid cooling plate 200, the coolant flows from the middle portion of the first liquid cooling plate 200 into the middle portion of the second liquid cooling plate 300, then flows along the second direction to both ends of the second liquid cooling plate 300, and finally flows into the interior of the first liquid cooling plate 200, achieving uniform cooling of the battery cells 110 stacked along the second direction. This ensures that the cooling effect is consistent across the battery cells 110 stacked along the second direction, both in the middle and at both ends, eliminating temperature differences and improving cooling and heat dissipation.

[0046] Optionally, N first liquid inlet connectors 203 are disposed between two first liquid outlet connectors 204 spaced apart along the second direction, and the middle portion of each second liquid cooling plate 300 is connected to N first liquid inlet connectors 203 , where N is an integer greater than 1. In this embodiment, N=3, meaning that each second liquid cooling plate 300 receives coolant through three first liquid inlet connectors 203 , improving coolant flow uniformity and ensuring smoother flow.

[0047] like Figure 5 and Figure 6 As shown, the first top wall 206 of the first liquid cooling plate 200 is evenly spaced with a plurality of fixing grooves 210. The individual battery cells 110 are inserted into these fixing grooves 210 one by one. Thermally conductive structural adhesive 120 is sandwiched between the bottom wall 112 of the individual battery cells 110 and the fixing grooves 210, and between the circumferential side walls of the individual battery cells 110 and the second liquid cooling plate 300. The thermally conductive structural adhesive 120 secures and seals the connection between the first liquid cooling plate 200 and the individual battery cells 110, and secures the individual battery cells 110 and the second liquid cooling plate 300. This not only enhances heat exchange efficiency but also improves the reliability of the connection between the first liquid cooling plate 200 and the second liquid cooling plate 300 and the individual battery cells 110.

[0048] Specifically, the thermal conductive structural adhesive 120 is formed by spraying 8 mm to 10 mm of liquid adhesive after placing the single battery cell 110 on the first liquid cooling plate 200 and then cooling and solidifying it, which will not be described in detail here.

[0049] In this embodiment, the thermal conductive structural adhesive 120 between the single battery cell 110 and the fixing groove 210 is annular, and the thermal conductive structural adhesive 120 between the single battery cell 110 and the second liquid cooling plate 300 is sheet-shaped. This is determined by the shapes of the single battery cell 110, the fixing groove 210 and the second liquid cooling plate 300, and will not be repeated here.

[0050] Optionally, the battery pack further comprises a bottom plate 220, which is spaced apart on a side of the first liquid cooling plate 200 away from the second liquid cooling plate 300, and an explosion-proof valve 111 is provided on the bottom wall 112 of the single cell 110. The inner bottom wall of the fixing groove 210 penetrates the first liquid cooling plate 200 to provide a pressure relief hole 211, and a sealing sheet 212 for blocking the pressure relief hole 211 is provided in the pressure relief hole 211. The explosion-proof valve 111 is provided corresponding to the pressure relief hole 211; when the single cell 110 is depressurized, the interior of the single cell 110 can communicate with the pressure relief cavity 221 between the first liquid cooling plate 200 and the bottom plate 220. The size of the fixing groove 210 matches the bottom size of the single battery cell 110, and the diameter of the pressure relief hole 211 is smaller than the diameter of the single battery cell 110 but larger than the diameter of the explosion-proof valve 111, so that the fixing groove 210 can support and fix the single battery cell 110, so as to ensure that the explosion-proof valve 111 can open normally and relieve pressure when the single battery cell 110 thermally runs away. The high-temperature and high-pressure gas generated by thermal runaway breaks through the sealing plate 212 and is introduced into the pressure relief cavity 221 between the first liquid cooling plate 200 and the bottom plate 220, and is finally discharged to the battery box outside the battery pack, thereby realizing explosion-proof pressure relief of the single battery cell 110; the first liquid cooling plate 200 can also cool the high-temperature gas ejected during thermal runaway, reduce the probability of heat spread, and has higher reliability.

[0051] Furthermore, the positive and negative poles of the single cell 110 are both arranged at the top, which is away from the first liquid cooling plate 200, ensuring that the coolant is away from the positive and negative poles of the single cell 110, and the battery pack is safer.

[0052] In this embodiment, the surfaces of the first liquid cooling plate 200 and the second liquid cooling plate 300 are coated with an insulating high-temperature resistant coating, which is used to achieve insulation between the single battery cell 110 and the first liquid cooling plate 200 and the second liquid cooling plate 300. At the same time, it prevents the coating from being damaged by high temperature after the single battery cell 110 has a thermal runaway, and prevents the thermal runaway from being converted into heat propagation and heat diffusion, thereby improving the safety and reliability of the battery pack. It will not be repeated here.

[0053] Example 1

[0054] like Figure 1 As shown, each cell group 100 is provided with the second liquid cooling plate 300 at both ends along the first direction, and one second liquid cooling plate 300 is sandwiched between two adjacent cell groups 100 along the first direction. This allows for three-sided cooling of a single cell 110, resulting in better cooling and ensuring high temperature consistency across the cells 110. However, this comes at a higher cost and will not be further elaborated here.

[0055] Optionally, the individual battery cells 110 are cylindrical, and the second sidewalls 303 of the second liquid cooling plate 300 along the first direction are wavy, so that the individual battery cells 110 are aligned with the second sidewalls 303 of the second liquid cooling plate 300 along the first direction. This configuration of the second liquid cooling plate 300 can increase the contact area with the individual battery cells 110, improve the connection reliability between the individual battery cells 110 and the second liquid cooling plate 300, and enhance the cooling effect of the second liquid cooling plate 300 on the individual battery cells 110. It can also reduce the size of the individual battery cells 110 along the second direction after assembly with the second liquid cooling plate 300, thereby increasing the energy density of the battery pack.

[0056] like Figure 6 As shown, the second sidewalls 303 of the second liquid cooling plate 300 at both ends along the first direction are wavy, and it has a plurality of mounting protrusions 310. The mounting protrusions 310 extend in the vertical direction and are arranged corresponding to the first liquid inlet connector 203, so as to facilitate the plug-in fixation of the first liquid inlet connector 203 and the second liquid cooling plate 300. The mounting protrusions 310 are located between two adjacent single battery cells 110, that is, located on the crest of the second liquid cooling plate 300. The mounting protrusions 310 have a hollow inner cavity, which is connected to the second liquid cooling flow channel of the second liquid cooling plate 300. In this way, the second liquid cooling plate 300 can be connected to the first liquid cooling plate 200.

[0057] Example 2

[0058] like Figure 2 As shown, the only difference between this second embodiment and the above-mentioned first embodiment is that each battery cell group 100 is only attached to one second liquid cooling plate 300, which can save materials, reduce costs, reduce production process steps, and improve manufacturing efficiency, but the heat dissipation effect is poor, and the temperature consistency of the single battery cell 110 is poor, which will not be repeated here.

[0059] Example 3

[0060] like Figure 3 The second embodiment shown differs from the first embodiment only in that multiple cell groups 100 are stacked along the second direction, each cell group 100 is attached to a second liquid cooling plate 300, and the second liquid cooling plates 300 attached to two adjacent cell groups 100 along the second direction are staggered in the first direction. This allows for single-sided cooling of the circumferential sidewalls of each individual cell 110. Compared to the first embodiment, the third embodiment offers lower costs but poorer heat dissipation and temperature consistency. However, compared to the second embodiment, the third embodiment offers higher temperature consistency for the individual cells 110, but its structure is more complex and more expensive, which will not be discussed further here.

[0061] This embodiment also provides a battery pack manufacturing method, which is used to manufacture the battery pack as described in any of the above solutions, including the following steps: S1, manufacturing the above-mentioned first liquid cooling plate 200 and the above-mentioned second liquid cooling plate 300; S2, connecting the second bottom walls 302 of the plurality of the above-mentioned second liquid cooling plates 300 to the first top wall 206 of the above-mentioned first liquid cooling plate 200, and the above-mentioned second liquid cooling plate 300 is extended along the second direction; S3, placing single battery cells 110 on the first top wall 206 of the above-mentioned first liquid cooling plate 200, so that the single battery cells 110 are stacked along the second direction to form a battery cell group 100, and at least one of the first side walls 101 at both ends of the battery cell group 100 along the first direction is attached to the second liquid cooling plate 300, and each single battery cell 110 is connected to the above-mentioned first liquid cooling plate 200 and the above-mentioned second liquid cooling plate 300 for heat exchange.

[0062] The battery pack manufactured by the battery pack manufacturing method in this embodiment can cool the circumferential side walls and bottom of the single battery cell 110, thereby achieving complete cooling of the single battery cell 110, and has better cooling and heat dissipation effects, thereby ensuring the safe and reliable operation of the single battery cell 110 in the battery pack; at the same time, the bottom of the second liquid cooling plate 300 is directly connected to the first top wall 206 of the first liquid cooling plate 200, and there is no need to use additional connecting pipes to connect the second liquid cooling plate 300 to the liquid cooling system of the battery pack, which simplifies the structure of the battery pack and the production process steps, thereby increasing the space in the battery pack for installing the single battery cell 110, improving the energy density of the battery pack, and also improving manufacturing efficiency and reducing manufacturing costs.

[0063] After completing the assembly of the first liquid cooling plate 200, the second liquid cooling plate 300 and the battery cell group 100, it is necessary to spray and fill 8mm to 10mm of liquid glue between the first liquid cooling plate 200 and the battery cell group 100, and then cool and solidify to form a thermal conductive structural glue 120, which is used to fix the single battery cell 110 and the first liquid cooling plate 200 and the second liquid cooling plate 300, while improving the heat exchange efficiency. It will not be repeated here.

[0064] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A battery pack, characterized in that: include: A plurality of battery cell groups (100) spaced apart along a first direction, the battery cell group (100) comprising a plurality of single battery cells (110) stacked along a second direction, the second direction being perpendicular to the first direction; a first liquid cooling plate (200), the first liquid cooling plate (200) being arranged at the bottom of the plurality of battery cell groups (100) and being used to support the battery cell groups (100); A plurality of second liquid cooling plates (300) are arranged extending along the second direction, the second bottom wall (302) of the second liquid cooling plate (300) is connected to the first liquid cooling plate (200), and at least one of the two first side walls (101) at both ends of each battery cell group (100) along the first direction is provided with the second liquid cooling plate (300), so that the single battery cell (110) is respectively connected to the first liquid cooling plate (200) and the second liquid cooling plate (300) for heat exchange.

2. The battery pack according to claim 1, wherein: A first liquid cooling channel is provided in the first liquid cooling plate (200), a second liquid cooling channel is provided in the second liquid cooling plate (300), and a first liquid inlet joint (203) is provided on either the first top wall (206) of the first liquid cooling plate (200) or the second bottom wall (302) of the second liquid cooling plate (300), one end of the first liquid inlet joint (203) is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel; and / or any one of the first top wall (206) of the first liquid cooling plate (200) and the second bottom wall (302) of the second liquid cooling plate (300) is provided with a first liquid outlet joint (204), one end of the first liquid outlet joint (204) is connected to the first liquid cooling channel, and the other end is connected to the second liquid cooling channel.

3. The battery pack according to claim 2, wherein: The first top wall (206) of the first liquid cooling plate (200) is provided with a plurality of first liquid inlet joints (203) and a plurality of first liquid outlet joints (204), the plurality of first liquid inlet joints (203) are arranged at intervals along the first direction, the plurality of first liquid outlet joints (204) are arranged at intervals along the first direction, and the first liquid inlet joints (203) and the first liquid outlet joints (204) are arranged at intervals in the second direction.

4. The battery pack according to claim 3, wherein: The first liquid outlet joints (204) are provided at both ends of the first liquid cooling plate (200) along the second direction, the first liquid inlet joint (203) is provided between the two first liquid outlet joints (204) spaced apart along the second direction, and the two ends of the second liquid cooling plate (300) along the second direction are connected to the two first liquid outlet joints (204) spaced apart along the second direction in a one-to-one correspondence.

5. The battery pack according to claim 4, characterized in that: N first liquid inlet connectors (203) are arranged between two first liquid outlet connectors (204) arranged at intervals along the second direction, and the middle portion of each second liquid cooling plate (300) is connected to N first liquid inlet connectors (203), where N is an integer greater than 1.

6. The battery pack according to any one of claims 1 to 5, characterized in that: The second liquid cooling plates (300) are provided at both ends of each battery cell group (100) along the first direction, and a second liquid cooling plate (300) is sandwiched between two adjacent battery cell groups (100) along the first direction.

7. The battery pack according to claim 6, characterized in that: The single battery cell (110) is a cylindrical battery cell, the second side walls (303) of the second liquid cooling plate (300) at both ends along the first direction are wavy, and the single battery cell (110) is adapted to the second side walls (303) of the second liquid cooling plate (300) at both ends along the first direction.

8. The battery pack according to claim 3, wherein: A plurality of the battery cell groups (100) are stacked along the second direction, each of the battery cell groups (100) is attached with a second liquid cooling plate (300), and the second liquid cooling plates (300) attached to two adjacent battery cell groups (100) along the second direction are staggered in the first direction.

9. The battery pack according to claim 1, wherein: The first top wall (206) of the first liquid cooling plate (200) is evenly spaced with a plurality of fixing grooves (210), the single battery cells (110) are inserted into the fixing grooves (210) one by one, and a heat-conducting structural adhesive (120) is sandwiched between the bottom wall (112) of the single battery cell (110) and the fixing grooves (210), and between the circumferential side wall of the single battery cell (110) and the second liquid cooling plate (300).

10. The battery pack according to claim 9, characterized in that: The battery pack further comprises a bottom plate (220), the bottom plate (220) being spaced apart and arranged on a side of the first liquid cooling plate (200) facing away from the second liquid cooling plate (300), an explosion-proof valve (111) being arranged on the bottom wall (112) of the single battery cell (110), a pressure relief hole (211) being arranged on the inner bottom wall of the fixing groove (210) penetrating the first liquid cooling plate (200), a sealing sheet (212) for blocking the pressure relief hole (211) being arranged in the pressure relief hole (211), and the explosion-proof valve (111) being arranged corresponding to the pressure relief hole (211); when the single battery cell (110) is depressurized, the interior of the single battery cell (110) can communicate with the pressure relief cavity (221) between the first liquid cooling plate (200) and the bottom plate (220).

11. A method for manufacturing a battery pack, characterized in that: For making a battery pack according to any one of claims 1 to 10, comprising the steps of: S1. Manufacturing the first liquid cooling plate (200) and the second liquid cooling plate (300); S2, connecting the second bottom walls (302) of the plurality of second liquid cooling plates (300) to the first top wall (206) of the first liquid cooling plate (200), wherein the second liquid cooling plates (300) are extended along a second direction; S3. Single cells (110) are placed on the first top wall (206) of the first liquid cooling plate (200), so that the single cells (110) are stacked along the second direction to form a cell group (100), and at least one of the first side walls (101) at both ends of the cell group (100) along the first direction is attached to the second liquid cooling plate (300), and each of the single cells (110) is connected to the first liquid cooling plate (200) and the second liquid cooling plate (300) for heat exchange.

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