Liquid cooling system and battery pack

Abstract

The utility model provides a liquid cooling system and a battery pack, the liquid cooling system at least comprises a liquid cooling assembly, the liquid cooling assembly is used for carrying out liquid cooling on a battery cell group, the liquid cooling assembly comprises a liquid cooling plate and a plastic current collecting piece, the liquid cooling plate is arranged on the side surface of the battery cell group, the liquid cooling plate is hollow, a liquid cooling flow channel is formed in the liquid cooling plate, and the plastic current collecting piece is arranged in the liquid cooling flow channel. A liquid inlet communicated with one end of the liquid cooling flow channel and a liquid outlet communicated with the other end of the liquid cooling flow channel are formed in the liquid cooling plate; the plastic flow collecting piece is formed on the liquid cooling plate in an injection molding mode, the plastic flow collecting piece and the liquid cooling plate are integrally arranged, the plastic flow collecting piece comprises a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel is used for communicating a liquid inlet and a liquid inlet pipeline of the liquid cooling plate, and the liquid outlet flow channel is used for communicating a liquid outlet and a liquid outlet pipeline of the liquid cooling plate.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery pack technical field, concretely relates to a liquid cooling system and battery pack. BACKGROUND

[0002] At present, cylindrical battery cells have been widely applied to electric vehicles due to higher energy density, better safety stability and lower cost, and are expected to become the future development trend of electric vehicle batteries. Large cylindrical battery packs need to be in contact with the liquid cooling plate on the side of the battery cell for thermal management. For example, the contact area between the serpentine tube liquid cooling plate and the battery cell is large, the cooling efficiency is high, and the pressure drop of the parallel liquid cooling system of the serpentine tube is small. However, the current collector at the end of the serpentine tube liquid cooling plate is usually made of metal, and the connection and sealing between the current collector and the serpentine tube liquid cooling plate are achieved by metal welding, which makes the overall weight of the liquid cooling system large and the cost high. SUMMARY

[0003] The embodiments of the utility model provide a liquid cooling system and battery pack, which can improve the technical problems of large overall weight and high cost of the liquid cooling system.

[0004] In a first aspect, the embodiments of the utility model provide a liquid cooling system, at least comprising one liquid cooling assembly, the liquid cooling assembly is used for liquid cooling of one battery cell group, and the liquid cooling assembly comprises:

[0005] A liquid cooling plate is arranged on the side of the battery cell group, the liquid cooling plate is hollow and has a liquid cooling flow channel formed therein, the liquid cooling plate is provided with a liquid inlet communicating with one end of the liquid cooling flow channel and a liquid outlet communicating with the other end of the liquid cooling flow channel; and

[0006] A plastic current collecting piece is injection molded on the liquid cooling plate and integrally arranged with the liquid cooling plate, the plastic current collecting piece comprises a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel is used for connecting the liquid inlet of the liquid cooling plate and a liquid inlet pipeline, and the liquid outlet flow channel is used for connecting the liquid outlet of the liquid cooling plate and a liquid outlet pipeline.

[0007] In an embodiment, the two ends of the liquid cooling flow channel are arranged on the same side;

[0008] The liquid cooling plate is integrally formed with a connecting portion, the connecting portion is hollow, one end of the connecting portion communicates with the two ends of the liquid cooling flow channel respectively, and the other end of the connecting portion is formed with the liquid inlet and the liquid outlet;

[0009] The plastic current collecting piece is injection molded on the other end of the connecting portion.

[0010] In an embodiment, in the length direction of the battery cell group, the liquid cooling plate has a first end portion, and the two ends of the liquid cooling flow channel are arranged close to the first end portion.

[0011] The first end portion is provided with a channel communicating both ends of the liquid cooling flow channel, and the end of the channel forms the liquid inlet and the liquid outlet.

[0012] The connecting portion includes the first end portion, and the plastic current collector is injection molded on the first end portion.

[0013] In an embodiment, one end of the plastic current collector is sleeved outside the first end portion in the length direction of the battery cell group, wherein:

[0014] The insertion length of the first end portion and the plastic current collector is H1, and 2mm≤H1≤200mm; and / or,

[0015] The insertion length of the first end portion and the plastic current collector is H1, the length of the connecting portion is H2, and 1mm≤H2-H1≤50mm.

[0016] In an embodiment, the liquid cooling plate has a first end portion in the length direction of the battery cell group, both ends of the liquid cooling flow channel pass through the first end portion, a connecting pipe is fixedly connected to the first end portion, one end of the connecting pipe communicates with both ends of the liquid cooling flow channel respectively, and the other end of the connecting pipe forms the liquid inlet and the liquid outlet.

[0017] The connecting portion includes the connecting pipe, and the plastic current collector is injection molded on the other end of the connecting pipe.

[0018] In an embodiment, the plastic current collector is sleeved outside the connecting pipe in the length direction of the battery cell group, wherein:

[0019] The insertion length of the connecting pipe and the plastic current collector is H3, and 2mm≤H3≤200mm; and / or,

[0020] The insertion length of the connecting pipe and the plastic current collector is H3, the length of the connecting pipe is H4, and 5mm≤H4-H3≤200mm; and / or,

[0021] The distance between the plastic current collector and the first end portion is H5, and H5 is greater than or equal to 3mm.

[0022] In an embodiment, the outer wall of the connecting pipe is provided with a limiting protruding rib;

[0023] The plastic current collector is sleeved outside the connecting pipe and abuts against the limiting protruding rib.

[0024] In an embodiment, the inner wall of the connecting pipe is provided with a limiting protruding rib;

[0025] The first end is inserted into one end of the connecting tube and abuts against the limiting protrusion.

[0026] In one embodiment, the plastic manifold is provided with a stepped groove. In the direction away from the opening of the stepped groove, the stepped groove includes a first groove segment and a second groove segment with decreasing groove diameter. The connection between the first groove segment and the second groove segment forms a stepped surface. The second groove segment has two independent cavities to respectively form the liquid inlet channel and the liquid outlet channel.

[0027] The connecting part is inserted into the groove of the step groove and abuts against the step surface.

[0028] In one embodiment, an annular groove is provided on the step surface, and the width of the annular groove is smaller than the wall thickness of the connecting portion.

[0029] In one embodiment, the other end of the connecting portion extends away from the liquid cooling plate, and the outer diameter of the connecting portion is gradually reduced in the direction away from the liquid cooling plate.

[0030] In one embodiment, the side of the liquid cooling plate is at least partially attached to and shaped to the side of the battery cell assembly.

[0031] In one embodiment, the liquid cooling plate is configured as a serpentine tube or a metal harmonica tube.

[0032] In one embodiment, along the length of the cell assembly, the liquid cooling plate includes multiple segments spliced ​​together. The multiple segments include connecting segments at both ends of the liquid cooling plate and multiple liquid cooling segments between two connecting segments. The two connecting segments are configured as straight segments. Each liquid cooling segment is fitted to the side of a cell in the cell assembly and is adapted in shape.

[0033] The liquid inlet and the liquid outlet are located on the same side and on a connecting plate segment, and the plastic manifold is correspondingly injection molded on the connecting plate segment.

[0034] In one embodiment, the liquid cooling system includes a plurality of liquid cooling components arranged side by side, with a battery cell assembly disposed between two adjacent liquid cooling components to liquid cool both sides of the battery cell assembly respectively.

[0035] In one embodiment, the plastic manifold can be made of one of nylon 66+ glass fiber, polyphenylene sulfide, polyphthalamide, and nylon 12.

[0036] Secondly, embodiments of the present invention provide a battery pack, comprising:

[0037] The liquid cooling system comprises a plurality of liquid cooling assemblies arranged side by side, and

[0038] A plurality of battery cell groups are arranged side by side, and each battery cell group is located between two adjacent liquid cooling assemblies.

[0039] The liquid cooling system is the liquid cooling system described above.

[0040] The embodiment of the utility model has the advantages of

[0041] In the embodiment of the utility model, the liquid cooling assembly in the liquid cooling system is used for liquid cooling the side surface of the battery cell group, and the liquid cooling assembly comprises a liquid cooling plate and a plastic current collecting piece; the liquid cooling plate is arranged on the side surface of the battery cell group and comprises a liquid cooling flow channel, the liquid cooling plate is made of metal and has high thermal conductivity, so that the liquid cooling effect of the liquid cooling plate on the side surface of the battery cell group is ensured; meanwhile, the liquid cooling plate is provided with a liquid inlet and a liquid outlet communicating with the liquid cooling flow channel, the plastic current collecting piece is arranged to communicate the liquid inlet and the liquid inlet pipeline and the liquid outlet and the liquid outlet pipeline; that is to say, the cooling liquid flows through the liquid inlet pipeline and the liquid inlet flow channel and flows to the liquid cooling flow channel from the liquid inlet, and heat exchange is carried out between the cooling liquid and the battery cell group in the cooling liquid flow process, so that the side surface of the battery cell group is liquid cooled; the cooling liquid flows through the liquid cooling flow channel and flows to the liquid outlet flow channel from the liquid outlet; in this way, a liquid cooling loop is formed, and the liquid cooling effect is improved; the plastic current collecting piece is injection molded on the liquid cooling plate and is arranged integrally with the liquid cooling plate, so that the weight of the plastic current collecting piece is reduced, the overall weight of the liquid cooling system is reduced, the cost of the plastic current collecting piece is reduced, and the connection strength and the sealing property of the plastic current collecting piece and the liquid inlet interface or the liquid outlet interface are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creating creative labor.

[0043] Figure 1 It is the first kind of three-dimensional schematic view of the liquid cooling system provided by the embodiment of the utility model;

[0044] Figure 2 It is the exploded schematic view of the liquid cooling system in Figure 1 ;

[0045] Figure 3 It is the enlarged schematic view of the local A in Figure 2 ;

[0046] Figure 4 It isFigure 1 a perspective view of the plastic current collector in the liquid cooling system in FIG.

[0047] Figure 5 is Figure 4 a sectional view of B-B in the liquid cooling system in FIG.

[0048] Figure 6 is Figure 1 a front view of the liquid cooling plate and plastic current collector joint in the liquid cooling system in FIG.

[0049] Figure 7 is a second perspective view of the liquid cooling system provided by the embodiment of the utility model;

[0050] Figure 8 is Figure 7 an exploded view of the liquid cooling system in FIG.

[0051] Figure 9 is Figure 8 an enlarged view of local part C in FIG.

[0052] Figure 10 is Figure 8 a perspective view of the plastic current collector in the liquid cooling system in FIG.

[0053] Figure 11 is Figure 10 a sectional view of D-D in the liquid cooling system in FIG.

[0054] Figure 12 is Figure 11 an enlarged view of local part E in FIG.

[0055] Figure 13 is Figure 8 a front view of the liquid cooling plate and plastic current collector joint in the liquid cooling system in FIG.

[0056] Figure 14 is a perspective view of the battery pack provided by the embodiment of the utility model.

[0057] The name of the component corresponding to the corresponding reference sign in the figure is:

[0058] 1000 battery pack; 100 liquid cooling system; 1 liquid cooling assembly; 11 liquid cooling plate; a liquid cooling flow channel; b liquid inlet; c liquid outlet; d side surface; e passage; 111a first end part; 111b second end part; 112 plate segment; 1121 connecting plate segment; 1122 liquid cooling plate segment; 12 plastic current collector; 121 liquid inlet flow channel; 122 liquid outlet flow channel; 123 first plate segment; 124 second plate segment; 125 limiting step; 13 connecting part; 14 connecting pipe; 141 outer wall; 142 limiting protruding rib; 143 limiting protruding part; 15 communicating part; 200 battery cell group; 201 side surface; 300 external pipeline; F1 length direction. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the utility model will be apparently and completely described in connection with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the person skilled in the art without creative labor belong to the scope of protection of the utility model. In addition, it should be understood that the specific implementation manners described herein are only used for illustration and explanation of the utility model, and are not used for limiting the utility model. In the utility model, the orientation words such as 'upper' and 'lower' are generally used for the upper and lower of the device in the actual use or working state, and the specific is the drawing direction in the drawings; and 'inner' and 'outer' are used for the contour of the device.

[0060] In a first aspect, the utility model provides a kind of liquid cooling system 100. Please refer to Figure 1 、 Figure 3 、 Figure 7 And Figure 14 The liquid cooling system 100 at least includes one liquid cooling assembly 1, the liquid cooling assembly 1 is used to carry out liquid cooling to one electric core group 200, the liquid cooling assembly 1 includes liquid cooling plate 11 and plastic current collector 12, the liquid cooling plate 11 is arranged at the side surface 201 of the electric core group 200, the liquid cooling plate 11 is hollowly arranged, and a liquid cooling flow channel a is formed in it, the liquid cooling plate 11 is provided with liquid inlet b communicating with one end of the liquid cooling flow channel a and liquid outlet c communicating with the other end of the liquid cooling flow channel a;The plastic current collector 12 is injection molded on the liquid cooling plate 11, and is integrally arranged with the liquid cooling plate 11, the plastic current collector 12 includes liquid inlet flow channel 121 and liquid outlet flow channel 122, the liquid inlet flow channel 121 is used to communicate the liquid inlet b of the liquid cooling plate 11 and liquid inlet pipeline 301, and the liquid outlet flow channel 122 is used to communicate the liquid outlet c of the liquid cooling plate 11 and liquid outlet pipeline 302.

[0061] It can be known that, in the related art, the current collector is machined from metal piece, and the machined current collector is welded to the liquid cooling plate 11 to constitute the liquid cooling system 100;Metal current collector not only increases the overall weight of the liquid cooling system 100, but also increases the cost of the liquid cooling system 100 by machining and metal welding process.

[0062] In the embodiments of the utility model, the liquid cooling plate 11 includes a liquid cooling flow channel a, the liquid cooling plate 11 is arranged at the side surface 201 of the electric core group 200, and the liquid cooling plate 11 made of metal has high thermal conductivity, so as to ensure the liquid cooling effect of the liquid cooling plate 11 on the side surface 201 of the electric core group 200.

[0063] Meanwhile, the liquid cooling plate 11 is provided with an inlet port b and an outlet port c communicating with the liquid cooling flow channel a, and the inlet port b and the inlet pipe 301 and the outlet port c and the outlet pipe 302 are communicated by arranging the plastic current collector 12; that is, the cooling liquid flows through the inlet pipe 301 and the inlet flow channel 121 and flows from the inlet port b to the liquid cooling flow channel a, and exchanges heat with the battery cell group 200 in the process of flowing, so as to realize liquid cooling of the side surface 201 of the battery cell group 200; the cooling liquid flows through the liquid cooling flow channel a and flows from the outlet port c to the outlet flow channel 122; thus, a liquid cooling loop is formed, and the liquid cooling effect is improved.

[0064] In the embodiment of the utility model, the plastic current collector 12 is injection molded on the liquid cooling plate 11 and is integrally arranged with the liquid cooling plate 11; the plastic current collector 12 formed by injection molding is lighter than a metal current collector, so as to reduce the overall weight of the liquid cooling system 100; the plastic current collector 12 is directly injection molded on the liquid cooling plate 11, compared with machining and metal welding process, the manufacturing and assembly process of the plastic current collector 12 can be simplified, so as to have lower cost, thereby reducing the overall manufacturing cost of the liquid cooling system 100; and the plastic current collector 12 is integrally arranged with the liquid cooling plate 11 by injection molding, so as to ensure the connection strength and sealing property of the plastic current collector 12 and the liquid cooling plate 11.

[0065] The plastic current collector 12 is provided with an inlet interface 126 and an outlet interface 127, the inlet interface 126 communicates the inlet flow channel 121 and the inlet pipe 301; the outlet interface 127 communicates the outlet flow channel 122 and the outlet pipe 302.

[0066] The number and position of the plastic current collector 12 are not limited in the application. In some embodiments, a single liquid cooling plate 11 cools two battery cell groups 200, the inlet port b and the outlet port c are correspondingly arranged at both ends of the liquid cooling plate 11, and one current collector is correspondingly arranged on the inlet port b and the outlet port c; in another embodiment, a single liquid cooling plate 11 cools two battery cell groups 200, the inlet port b and the outlet port c are arranged on the same side of one end of the liquid cooling plate 11, and one current collector is arranged on the one end of the liquid cooling plate 11; in some other embodiments, a single liquid cooling plate 11 is arranged in a bending manner and can cool more than three battery cell groups 200 at the same time, the inlet port b and the outlet port c are arranged on the same side of both ends of the liquid cooling plate 11, and one current collector is correspondingly arranged on the inlet port b and the outlet port c. The number and position of the plastic current collector are not limited, and the plastic current collector is suitable for various types of liquid cooling plates 11.

[0067] In the "single liquid cooling plate 11 cools two battery cell groups 200" embodiment, the two ends of the liquid cooling flow channel a can be disposed on the same side or opposite sides; correspondingly, the liquid inlet b and the liquid outlet c on the liquid cooling plate 11 can be disposed on the same side or opposite sides.

[0068] Taking "the two ends of the liquid cooling flow channel a are disposed on the same side" as an example, the structure of the liquid cooling flow channel a is not specifically limited in the present application. In an embodiment, the liquid cooling flow channel a includes a first flow section, a second flow section, and a connecting flow section. The first flow section and the second flow section are disposed in parallel and along the length direction F1 of the battery cell group 200. In the length direction F1 of the battery cell group 200, the two ends of the first flow section and the second flow section on the same side are communicated through the connecting flow section, and the other two ends of the first flow section and the second flow section on the same side correspond to form the two ends of the liquid cooling flow channel a, respectively.

[0069] In another embodiment, the liquid cooling flow channel a includes a third flow section and a fourth flow section. The third flow section and the fourth flow section are disposed in parallel and along the length direction F1 of the battery cell group 200. In the length direction F1 of the battery cell group 200, the two ends of the third flow section and the fourth flow section on the same side penetrate through the liquid cooling plate 11, and the liquid cooling plate 11 is further provided with a communicating piece 15 to communicate the two ends of the third flow section and the fourth flow section on the same side. The other two ends of the third flow section and the fourth flow section on the same side correspond to form the two ends of the liquid cooling flow channel a, respectively.

[0070] Taking "the liquid cooling flow channel a includes a third flow section and a fourth flow section, the two ends of the third flow section and the fourth flow section on the same side penetrate through the liquid cooling plate 11 and are communicated through the communicating piece 15, and the other two ends of the third flow section and the fourth flow section on the same side correspond to form the two ends of the liquid cooling flow channel a" as an example for description. The two ends of the liquid cooling flow channel a are disposed on the same side. The liquid cooling plate 11 is integrally formed with a connecting portion 13. The connecting portion 13 is hollowly disposed. One end of the connecting portion 13 is in communication with the two ends of the liquid cooling flow channel a, respectively. The other end of the connecting portion 13 is formed with the liquid inlet b and the liquid outlet c. The plastic current collector 12 is injection molded on the other end of the connecting portion 13. In this way, only one plastic current collector 12 needs to be provided on each liquid cooling plate 11, which can maximize the number of plastic current collectors 12. At the same time, the plastic current collector 12 is injection molded on the connecting portion 13, which can make the plastic current collector 12 more easily injection molded.

[0071] Based on the above embodiments, please refer to Figure 2 and Figure 3In the length direction F1 of the battery cell group 200, the liquid cooling plate 11 has opposite first and second end portions 111a and 111b, one end of the third flow section penetrates the second end portion 111b, the same side one end of the fourth flow section penetrates the second end portion 111b, and the communication member 15 is arranged at the second end portion 111b to communicate the third and fourth flow sections.

[0072] Referring to Figures 1 to 6 In the first embodiment of the present application, the two ends of the liquid cooling flow channel a are arranged close to the first end portion 111a, the first end portion 111a is provided with a passage e communicating the two ends of the liquid cooling flow channel a, and the end of the passage e forms the liquid inlet b and the liquid outlet c; wherein the connecting portion 13 comprises the first end portion 111a, and the plastic current collector 12 is injection molded on the first end portion 111a.

[0073] In the first embodiment of the present application, the two ends of the liquid cooling flow channel a are arranged close to the first end portion 111a, the first end portion 111a is provided with a passage e communicating the two ends of the liquid cooling flow channel a, and the end of the passage e forms the liquid inlet b and the liquid outlet c; wherein the connecting portion 13 comprises the first end portion 111a, and the plastic current collector 12 is injection molded on the first end portion 111a.

[0074] Specifically, in the first embodiment, when the plastic current collector 12 is injection molded on the first end portion 111a, one end of the plastic current collector 12 is sleeved outside the first end portion 111a, referring to Figure 6 In the length direction F1 of the battery cell group 200, wherein:

[0075] The insertion length of the first end portion 111a and the plastic current collector 12 is H1, and 2mm≤H1≤200mm; when the insertion length H1 of the plastic current collector 12 and the liquid cooling plate 11 is less than 2mm, the connection strength of the plastic current collector 12 and the liquid cooling plate 11 is small, and the plastic current collector 12 is prone to fall off from the liquid cooling plate 11; when the insertion length H1 of the plastic current collector 12 and the liquid cooling plate 11 is greater than 200mm, the size of the plastic current collector 12 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1; by setting the insertion length H1 of the first end portion 111a and the plastic current collector 12 to 2mm-200mm, not only the lap length of the plastic current collector 12 and the liquid cooling plate 11 is ensured to be sufficient, thereby improving the connection strength of the plastic current collector 12 and the liquid cooling plate 11, but also the size of the plastic current collector 12 does not need to be increased, thereby controlling the overall size of the liquid cooling assembly 1.

[0076] The first end portion 111a is provided with a plug-in length H1 of the plastic current collector 12, the length of the connecting portion 13 is H2, and 1mm≤H2-H1≤50mm. It can be understood that before the plastic current collector 12 is injection molded on the first end portion 111a, the surface of the liquid cooling plate 11 needs to be treated at a position close to the first end portion 111a to form the connecting portion 13. After the first end portion 111a is plugged into the plastic current collector 12, part of the surface treated position is exposed outside the plastic current collector 12, and the exposed size is 1mm-50mm. When the length difference is less than 1mm, based on the process tolerance of the plastic current collector 12, the coverage area of the plastic current collector 12 on the liquid cooling plate 11 will exceed the surface treated area on the liquid cooling plate 11, thereby reducing the connection strength of the plastic current collector 12 and the liquid cooling plate 11. When the length difference is greater than 50mm, the surface treated area on the liquid cooling plate 11 is larger, which will increase the process cost. The length exceeding the plastic current collector 12 is set to 1mm-50mm, which not only ensures that the plastic current collector 12 is overlapped on the surface treated area of the liquid cooling plate 11, but also controls the range of the surface treated area of the liquid cooling plate 11, thereby avoiding process waste.

[0077] It should be noted that the above two technical features can be set separately or simultaneously. Specifically, in an embodiment, the above two technical features are set simultaneously.

[0078] The application does not make specific limitations on the plug-in length H1 of the connecting portion 13 and the plastic current collector 12. The plug-in length H1 of the connecting portion 13 and the plastic current collector 12 can be set to 2mm, 10mm, 20mm, 50mm, 100mm and 200mm.

[0079] The application does not make specific limitations on the length difference H2-H1. The length difference H2-H1 can be set to 1mm, 10mm, 20mm, 30mm, 40mm and 50mm.

[0080] Please refer to Figures 7 to 13 In the second embodiment of the application, the two ends of the liquid cooling channel a are provided on the same side and penetrate the first end portion 111a. The first end portion 111a is fixedly connected with a connecting pipe 14, one end of the connecting pipe 14 is in communication with the two ends of the liquid cooling channel a, and the other end of the connecting pipe 14 forms the liquid inlet b and the liquid outlet c. The connecting portion 13 includes the connecting pipe 14, and the plastic current collector 12 is injection molded on the other end of the connecting pipe 14.

[0081] In the second embodiment of the present application, the connecting pipe 14 is fixedly connected to the first end portion 111a, and the other end of the connecting pipe 14 forms the liquid inlet b and the liquid outlet c; the plastic current collector 12 is injection molded on the other end of the connecting pipe 14. In the actual process, the plastic current collector 12 can be injection molded on the connecting pipe 14, and then the connecting pipe 14 is welded with the liquid cooling plate 11, so that the injection difficulty of the plastic current collector 12 can be further reduced.

[0082] Specifically, in the second embodiment, the plastic current collector 12 is sleeved outside the connecting pipe 14, please refer to Figure 12 In the length direction F1 of the battery cell group 200, wherein:

[0083] The insertion length H3 of the connecting pipe 14 and the plastic current collector 12 is 2mm≤H3≤200mm; when the insertion length H3 of the plastic current collector 12 and the connecting pipe 14 is less than 2mm, the connection strength of the plastic current collector 12 and the connecting pipe 14 is small, and the plastic current collector 12 is easy to fall off from the connecting pipe 14; when the insertion length H3 of the plastic current collector 12 and the connecting pipe 14 is greater than 200mm, the size of the plastic current collector 12 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1; by setting the insertion length H3 of the plastic current collector 12 and the connecting pipe 14 to 2mm-200mm, not only the lap length of the plastic current collector 12 and the connecting pipe 14 is enough, thereby improving the connection strength of the plastic current collector 12 and the connecting pipe 14, but also the size of the plastic current collector 12 does not need to be increased, thereby controlling the overall size of the liquid cooling assembly 1.

[0084] The insertion length of the connecting pipe 14 and the plastic current collector 12 is set to H3, the length of the connecting pipe 14 is set to H4, and 5mm≤H4-H3≤200mm; when the length H4-H3 of the connecting pipe 14 exposed outside the plastic current collector 12 is less than 5mm, the welding space of the connecting pipe 14 and the liquid cooling plate 11 is not enough; when the length H4-H3 of the connecting pipe 14 exposed outside the plastic current collector 12 is greater than 200mm, the size of the connecting pipe 14 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1; by setting the length H4-H3 of the connecting pipe 14 exposed outside the plastic current collector 12 to 5mm-200mm, not only the welding space of the connecting pipe 14 and the liquid cooling plate 11 is enough, but also the size of the connecting pipe 14 can be reasonably controlled.

[0085] The distance between the plastic current collector 12 and the first end portion 111a is H5, and H5 is greater than or equal to 3 mm. It can be understood that one end of the connecting pipe 14 is sleeved on the first end portion 111a, and the plastic current collector 12 is injection molded on the other end of the connecting pipe 14. Generally, the connecting pipe 14 and the first end portion 111a are welded by laser. The distance H5 between the plastic current collector 12 and the first end portion 111a is greater than or equal to 3 mm, so that there is enough distance between the first end portion 111a and the plastic current collector 12, thereby providing enough welding space for the connecting pipe 14.

[0086] It should be noted that the above three technical features can be set by one, two or all of them. Specifically, in an embodiment, the above two technical features are set at the same time.

[0087] The application does not make specific limitations on the insertion length H3 of the connecting pipe 14 and the plastic current collector 12. The insertion length H3 of the connecting pipe 14 and the plastic current collector 12 can be set to 2 mm, 10 mm, 20 mm, 50 mm, 100 mm and 200 mm.

[0088] The application does not make specific limitations on the length H4-H3 of the connecting pipe 14 exposed outside the plastic current collector 12. The length H4-H3 of the connecting pipe 14 exposed outside the plastic current collector 12 can be set to 5 mm, 10 mm, 20 mm, 50 mm, 100 mm and 200 mm.

[0089] The application does not make specific limitations on the distance H5 between the plastic current collector 12 and the first end portion 111a. The distance H5 between the plastic current collector 12 and the first end portion 111a is greater than or equal to 3 mm and less than or equal to H4-3 mm. The distance H5 between the plastic current collector 12 and the first end portion 111a can be set to 3 mm, 10 mm, 20 mm, 50 mm, 100 mm and 197 mm.

[0090] In an embodiment, referring to Figure 9 The outer wall 141 of the connecting pipe 14 protrudes a limiting convex rib 142, and the plastic current collector 12 is sleeved on the outer side of the connecting pipe 14 and abuts against the limiting convex rib 142. The limiting convex rib 142 is set to limit the insertion length H3 of the connecting pipe 14 and the plastic current collector 12, thereby avoiding that the plastic current collector 12 exceeds the maximum insertion length during injection molding.

[0091] In an embodiment, the inner wall of the connecting pipe 14 is provided with a limiting protrusion 143, the first end portion 111a is inserted into one end of the connecting pipe 14 and abuts against the limiting protrusion 143; by providing the limiting protrusion 143, the insertion position of the connecting pipe 14 and the first end portion 111a is limited, so as to avoid the first end portion 111a being too close to the plastic current collector 12 due to a large insertion length of the connecting pipe 14 and the plastic current collector 12, thereby ensuring that there is sufficient distance between the first end portion 111a and the plastic current collector 12 and providing sufficient welding space for the connecting pipe 14.

[0092] Based on the first and second embodiments, please refer to Figure 11 and Figure 12 , the plastic current collector 12 is provided with a stepped groove 123, in the direction away from the groove opening 123a of the stepped groove 123, the stepped groove 123 comprises a first groove section 1231 and a second groove section 1232 with decreasing groove diameters, the connection between the first groove section 1231 and the second groove section 1232 forms a stepped surface 1233, and two independent cavities 1234 are formed in the second groove section 1232 to correspond to the liquid inlet flow channel 121 and the liquid outlet flow channel 122 respectively; the connecting portion 13 is inserted into the groove opening 123a of the stepped groove 123 and abuts against the stepped surface 1233. That is, the first groove section 1231 and the second groove section 1232 are formed in the plastic current collector 12, the first groove section 1231 forms the liquid inlet flow channel 121 and the liquid outlet flow channel 122, and the second groove section 1232 is sleeved outside the connecting portion 13, so as to further reduce the injection molding difficulty of the plastic current collector 12.

[0093] Specifically, the connection between the first groove section 1231 and the second groove section 1232 forms a stepped surface 1233, the connecting portion 13 is inserted into the groove opening 123a of the stepped groove 123 and abuts against the stepped surface 1233; by providing the stepped groove 123 and the stepped surface 1233, the insertion length H3 of the connecting pipe 14 and the plastic current collector 12 is limited, so as to avoid the plastic current collector 12 exceeding the maximum insertion length during injection molding.

[0094] In an embodiment, the stepped surface 1233 is provided with an annular groove 1235, and the width of the annular groove 1235 is less than the wall thickness of the connecting portion 13. The annular groove 1235 is provided so that the inside of the plastic current collector 12 is hollow, which can further reduce the weight of the plastic current collector 12 and further reduce the overall weight of the liquid cooling system 100.

[0095] It can be known that in the above first and second embodiments, the plastic current collector 12 is injection molded on the first end 111a of the liquid cooling plate 11, or the plastic current collector 12 is injection molded on the connecting pipe 14; in order to improve the connection strength of the plastic current collector 12, the liquid cooling plate 11 or the connecting pipe 14 needs to be surface treated. The metal surface is usually nano-treated, plasma cleaned, oxidized, passivated or anodized, so as to improve the connection strength of the plastic current collector 12.

[0096] After the surface treatment of the liquid cooling plate 11 or the connecting pipe 14, the other end of the connecting part 13 extends away from the liquid cooling plate 11, and in the direction away from the liquid cooling plate 11, the outer diameter of the connecting part 13 is tapered; the plastic current collector 12 is sleeved on the outside of the connecting part 13; in this way, the connection strength of the plastic current collector 12 and the connecting part 13 can be improved.

[0097] The material of the plastic current collector 12 is not limited in the application, and the material of the plastic current collector 12 can be one of PA66+GF (nylon 66 plus glass fiber), PPS (English full name: Polyphenylene Sulfide, Chinese abbreviation: polyphenylene sulfide), PPE (English full name: Polyphthalamide, Chinese abbreviation: polyphthalamide) and PA12 (nylon 12). Preferably, the material of the plastic current collector 12 is nylon, which can not only reduce the risk of electrical short circuit and the cost of insulation spraying, but also has a smaller density, which can improve the overall energy density of the battery pack 1000.

[0098] In an embodiment, the side d of the liquid cooling plate 11 at least partially abuts and is shaped to fit the side 201 of the battery cell group 200; the side d of the liquid cooling plate 11 is arranged to abut and be shaped to fit the side 201 of the battery cell group 200. Thus, the contact area of the liquid cooling plate 11 and the battery cell group 200 is increased, and the cooling effect of the liquid cooling system 100 is further improved.

[0099] It can be known that the mainstream battery cell types on the market at present include cylindrical battery cells, square battery cells and soft package battery cells, among which the 4680 cylindrical battery has higher energy density, better safety stability and higher economy after grouping, and is expected to become the development trend of electric vehicle batteries.

[0100] For example, the liquid cooling plate 11 is set as a serpentine tube or a metal harmonica tube; in this way, the serpentine tube or the metal harmonica tube is in contact with the side surface 201 of the cylindrical battery cell to exchange heat, and the serpentine tube or the metal harmonica tube has a large contact area with the cylindrical battery cell, so that the serpentine tube or the metal harmonica tube has high cooling efficiency, and the liquid cooling system 100 has small pressure drop.

[0101] The liquid cooling plate 11 is not limited in structure in the present application. For example, the liquid cooling plate 11 is set as a serpentine tube, please refer to Figure 2 and Figure 8 In the length direction F1 of the battery cell group 200, the liquid cooling plate 11 includes a plurality of plate segments 112 which are spliced with each other, the plurality of plate segments 112 include a connecting plate segment 1121 at both ends of the liquid cooling plate 11, and a plurality of liquid cooling plate segments 1122 between the two connecting plate segments 1121, the two connecting plate segments 1121 are set as straight plate segments 112, each liquid cooling plate segment 1122 is attached to the side surface 201 of one battery cell in the battery cell group 200 and has a shape adapted thereto; the liquid inlet b and the liquid outlet c are arranged on the same side and on one connecting plate segment 1121, and the plastic current collector 12 is injection molded on the connecting plate segment 1121.

[0102] In the present embodiment, the liquid cooling plate segment 1122 is attached to the side surface 201 of one battery cell in the battery cell group 200 and has a shape adapted thereto, so as to ensure that the liquid cooling plate segment 1122 has a large contact area with the battery cell, and further improve the liquid cooling effect of the liquid cooling plate 11; at the same time, the connecting plate segment 1121 is set as a straight plate segment, so that the plastic current collector 12 is more easily injection molded on the connecting plate segment 1121.

[0103] Generally, the battery cell group 200 is usually provided with a plurality of battery cell groups; in order for the plurality of battery cell groups 200 to be liquid cooled and heat dissipated, in an embodiment, the liquid cooling system 100 includes a plurality of liquid cooling assemblies 1, the plurality of liquid cooling assemblies 1 are arranged side by side, and one battery cell group 200 is arranged between two adjacent liquid cooling assemblies 1 to liquid cool two sides of the battery cell group 200; in this way, the two sides of each battery cell group 200 can be liquid cooled by the liquid cooling assembly 1, which not only makes the structure of the liquid cooling system 100 more reasonable, but also further improves the liquid cooling effect of the liquid cooling system 100.

[0104] It can be understood that the connection mode of the plurality of liquid cooling assemblies 1 is not limited; the plurality of liquid cooling assemblies 1 can be arranged in parallel or in series; preferably, the plurality of liquid cooling assemblies 1 are arranged in parallel, so that the flow resistance of the liquid cooling system 100 can be reduced.

[0105] In a second aspect, the embodiments of the present application also provide a battery pack 1000. Please refer to Figure 14 The battery pack 1000 comprises a liquid cooling system 100 and a plurality of battery cell groups 200; the liquid cooling system 100 comprises a plurality of liquid cooling assemblies 1, and the plurality of liquid cooling assemblies 1 are arranged side by side; the plurality of battery cell groups 200 are arranged side by side, and each battery cell group 200 is located between two adjacent liquid cooling assemblies 1. It should be noted that the liquid cooling system 100 is the liquid cooling system 100 described above, that is, the liquid cooling system 100 has all the technical features of the liquid cooling system 100 described above, that is, the battery pack 1000 comprises all the embodiments of the liquid cooling system 100 described above.

[0106] The liquid cooling assembly 1 comprises a liquid cooling plate 11 and a plastic current collector 12, the liquid cooling plate 11 comprises a liquid cooling flow channel a, the liquid cooling plate 11 is arranged on the side surface 201 of the battery cell group 200, and the liquid cooling plate 11 made of metal has high thermal conductivity, thereby ensuring the liquid cooling effect of the liquid cooling plate 11 on the side surface 201 of the battery cell group 200.

[0107] Meanwhile, the liquid cooling plate 11 is provided with an inlet b and an outlet c communicating with the liquid cooling flow channel a, the inlet b and the inlet pipeline 301 and the outlet c and the outlet pipeline 302 are communicated by arranging the plastic current collector 12; that is, the cooling liquid flows through the inlet pipeline 301 and the inlet flow channel 121, and flows from the inlet b to the liquid cooling flow channel a, and exchanges heat with the battery cell group 200 in the process of flowing, thereby realizing liquid cooling of the side surface 201 of the battery cell group 200; the cooling liquid flows through the liquid cooling flow channel a and flows from the outlet c to the outlet flow channel 122; in this way, a liquid cooling loop is formed, and the liquid cooling effect is improved.

[0108] The plastic current collector 12 is integrally formed on the liquid cooling plate 11 by injection molding, and the plastic current collector 12 is lighter than a metal current collector, thereby reducing the overall weight of the liquid cooling system 100; the plastic current collector 12 is directly formed on the liquid cooling plate 11 by injection molding, thereby simplifying the manufacturing and assembly processes of the plastic current collector 12, reducing the cost, and reducing the overall manufacturing cost of the liquid cooling system 100; and the plastic current collector 12 is integrally formed on the liquid cooling plate 11 by injection molding, thereby ensuring the connection strength and sealing performance of the plastic current collector 12 and the liquid cooling plate 11.

[0109] The above detailed description of the embodiments of the present application is provided, and the principles and implementation modes of the present application are described by using specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation modes and application ranges will be changed according to the idea of the present application. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A liquid cooling system, characterized in that, It includes at least one liquid cooling assembly for liquid cooling a battery cell assembly, the liquid cooling assembly comprising: A liquid cooling plate is disposed on the side of the battery cell assembly. The liquid cooling plate is hollow and has a liquid cooling channel formed therein. The liquid cooling plate is provided with an inlet communicating with one end of the liquid cooling channel and an outlet communicating with the other end of the liquid cooling channel; and, A plastic manifold is injection molded onto the liquid cooling plate and integrally formed with the liquid cooling plate. The plastic manifold includes an inlet channel and an outlet channel. The inlet channel is used to connect the liquid inlet and the liquid inlet pipe of the liquid cooling plate, and the outlet channel is used to connect the liquid outlet and the liquid outlet pipe of the liquid cooling plate.

2. The liquid cooling system according to claim 1, characterized in that, The two ends of the liquid cooling channel are arranged on the same side; A connecting part is integrally formed on the liquid cooling plate. The connecting part is hollow and one end is connected to both ends of the liquid cooling channel. The other end forms the liquid inlet and the liquid outlet. The plastic manifold is injection molded at the other end of the connecting portion.

3. The liquid cooling system according to claim 2, characterized in that, Along the length of the battery cell assembly, the liquid cooling plate has a first end, and the two ends of the liquid cooling channel are disposed close to the first end; The first end is provided with a channel connecting the two ends of the liquid cooling channel, and the end of the channel forms the liquid inlet and the liquid outlet; The connecting portion includes the first end portion, and the plastic manifold is injection molded at the first end portion.

4. The liquid cooling system according to claim 3, characterized in that, One end of the plastic current collector is sleeved on the outside of the first end, along the length of the battery cell assembly, wherein: The insertion length between the first end and the plastic manifold is set to H1, and 2mm ≤ H1 ≤ 200mm; and / or, The insertion length between the first end and the plastic manifold is set to H1, and the length of the connecting part is set to H2, with 1mm≤H2-H1≤50mm.

5. The liquid cooling system according to claim 2, characterized in that, Along the length of the battery cell assembly, the liquid cooling plate has a first end, and both ends of the liquid cooling channel pass through the first end. A connecting pipe is fixedly connected to the first end, one end of the connecting pipe is connected to both ends of the liquid cooling channel, and the other end of the connecting pipe forms the liquid inlet and the liquid outlet. The connecting part includes the connecting pipe, and the plastic manifold is injection molded at the other end of the connecting pipe.

6. The liquid cooling system according to claim 5, characterized in that, The plastic current collector is sleeved on the outside of the connecting tube, along the length of the battery cell assembly, wherein: The insertion length between the connecting pipe and the plastic manifold is set to H3, and 2mm ≤ H3 ≤ 200mm; and / or, The insertion length between the connecting pipe and the plastic manifold is set to H3, and the length of the connecting pipe is set to H4, where 5mm ≤ H4 - H3 ≤ 200mm; and / or, The distance between the plastic manifold and the first end is set to H5, where H5 is greater than or equal to 3mm.

7. The liquid cooling system according to claim 5, characterized in that, The outer wall of the connecting pipe is provided with a limiting rib; The plastic manifold is sleeved on the outside of the connecting pipe and abuts against the limiting rib.

8. The liquid cooling system according to claim 5, characterized in that, The inner wall of the connecting pipe is provided with a limiting protrusion; The first end is inserted into one end of the connecting tube and abuts against the limiting protrusion.

9. The liquid cooling system according to claim 2, characterized in that, The plastic manifold is provided with a stepped groove. In the direction away from the groove opening, the stepped groove includes a first groove segment and a second groove segment with decreasing groove diameter. The connection between the first groove segment and the second groove segment forms a stepped surface. The second groove segment has two independent cavities to respectively form the liquid inlet channel and the liquid outlet channel. The connecting part is inserted into the groove of the step groove and abuts against the step surface.

10. The liquid cooling system according to claim 9, characterized in that, An annular groove is provided on the step surface, and the width of the annular groove is less than the wall thickness of the connecting part.

11. The liquid cooling system according to claim 2, characterized in that, The other end of the connecting part extends away from the liquid cooling plate, and the outer diameter of the connecting part is gradually reduced in the direction away from the liquid cooling plate.

12. The liquid cooling system according to any one of claims 2-11, characterized in that, The side of the liquid cooling plate is at least partially attached to the side of the battery cell assembly and its shape is adapted to it.

13. The liquid cooling system according to claim 12, characterized in that, The liquid cooling plate is configured as a serpentine tube or a metal harmonica tube.

14. The liquid cooling system according to claim 12, characterized in that, Along the length of the cell assembly, the liquid cooling plate includes multiple segments spliced ​​together. The multiple segments include connecting segments at both ends of the liquid cooling plate and multiple liquid cooling segments between two connecting segments. The two connecting segments are configured as straight segments. Each liquid cooling segment is fitted to the side of a cell in the cell assembly and is adapted in shape. The liquid inlet and the liquid outlet are located on the same side and on a connecting plate segment, and the plastic manifold is correspondingly injection molded on the connecting plate segment.

15. The liquid cooling system according to any one of claims 2-11, characterized in that, The liquid cooling system includes multiple liquid cooling components arranged side by side, with a battery cell assembly positioned between two adjacent liquid cooling components to liquid cool both sides of the battery cell assembly.

16. The liquid cooling system according to claim 1, characterized in that, The material of the plastic manifold can be one of nylon 66+ glass fiber, polyphenylene sulfide, polyphthalamide, and nylon 12.

17. A battery pack, characterized in that, include: A liquid cooling system, comprising multiple liquid cooling components arranged side-by-side; and, Multiple battery cell groups are arranged side by side, with each battery cell group located between two adjacent liquid cooling components; The liquid cooling system is configured as described in any one of claims 1-16.

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