Liquid cooling system and battery pack

Abstract

The invention 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, and a liquid cooling flow channel is formed in the liquid cooling plate; 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 present invention relates to the technical field of battery packs, and in particular to a liquid cooling system and a battery pack. Background Art

[0002] At present, cylindrical batteries have been widely promoted and applied in electric vehicles because of their higher energy density, better safety and stability, and lower cost, and are expected to become the future development trend of electric vehicle batteries. Large cylindrical battery packs require liquid cooling plates to contact the sides of the battery cells for thermal management. Taking the serpentine tube as an example, the serpentine tube liquid cooling plate has a large contact area with the battery cell and high cooling efficiency. At the same time, the serpentine tube parallel liquid cooling system has a small pressure drop; however, the current collector at the end of the serpentine tube liquid cooling plate is usually made of metal parts, and the current collector and the serpentine tube liquid cooling plate are connected and sealed by metal welding, which makes the overall weight of the liquid cooling system large and the cost high. Summary of the invention

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

[0004] In a first aspect, an embodiment of the present invention provides a liquid cooling system, comprising at least one liquid cooling component, wherein the liquid cooling component is used to liquid cool a battery cell group, and the liquid cooling component comprises:

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

[0006] A plastic current collecting part, which is injection molded on the liquid cooling plate and is integrally arranged with the liquid cooling plate. The plastic current collecting part includes a liquid inlet channel and a liquid outlet channel. The liquid inlet channel is used to connect the liquid inlet and the liquid inlet pipeline of the liquid cooling plate, and the liquid outlet channel is used to connect the liquid outlet and the liquid outlet pipeline of the liquid cooling plate.

[0007] In one embodiment, the two ends of the liquid cooling 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 which is respectively connected to the two ends of the liquid cooling channel, and the other end of which is formed with the liquid inlet and the liquid outlet;

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

[0010] In one embodiment, in the length direction of the battery cell group, the liquid cooling plate has a first end, and both ends of the liquid cooling channel are arranged close to the first end;

[0011] The first end portion is provided with a channel connecting the two ends of the liquid cooling channel, and the ends of the channel form the liquid inlet and the liquid outlet;

[0012] Wherein, the connecting portion includes the first end portion, and the plastic current collecting member is injection molded on the first end portion.

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

[0014] The insertion length between the first end and the plastic current collecting member is set to H1, and 2mm≤H1≤200mm; and / or,

[0015] The plug-in length between the first end and the plastic current collecting member is set to H1, the length of the connecting portion is set to H2, and 1mm≤H2-H1≤50mm.

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

[0017] Wherein, the connecting portion includes the connecting tube, and the plastic current collecting piece is injection molded at the other end of the connecting tube.

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

[0019] The plug-in length between the connecting pipe and the plastic current collecting piece is set to H3, and 2mm≤H3≤200mm; and / or,

[0020] The plug-in length between the connecting tube and the plastic current collecting member is set to H3, the length of the connecting tube is set to H4, and 5mm≤H4-H3≤200mm; and / or,

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

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

[0023] The plastic current collecting piece is sleeved on the outer side of the connecting pipe and abuts against the limiting convex rib.

[0024] In one embodiment, a limiting protrusion is protruded from the inner wall of the connecting pipe;

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

[0026] In one embodiment, the plastic current collecting member is provided with a step groove, and in the direction away from the notch of the step groove, the step groove includes a first groove section and a second groove section with decreasing groove diameters, a step surface is formed at the connection between the first groove section and the second groove section, and two independent cavities are formed in the second groove section to respectively correspond to form the liquid inlet flow channel and the liquid outlet flow channel;

[0027] The connecting portion is inserted into the notch 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 in a direction 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, at least a portion of the side surface of the liquid cooling plate is in contact with the side surface of the battery cell group and has a matching shape.

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

[0032] In one embodiment, in the length direction of the battery cell group, the liquid cooling plate includes a plurality of plate segments spliced ​​to each other, the plurality of plate segments include connecting plate segments located at both ends of the liquid cooling plate, and a plurality of liquid cooling plate segments located between two connecting plate segments, the two connecting plate segments are configured as straight plate segments, and each of the liquid cooling plate segments is in contact with a side surface of a battery cell in the battery cell group and has a matching shape;

[0033] The liquid inlet and the liquid outlet are arranged on the same side and on one of the connecting plate sections, and the plastic current collecting piece is correspondingly injection-molded on the connecting plate section.

[0034] In one embodiment, the liquid cooling system includes a plurality of the liquid cooling components, and the plurality of the liquid cooling components are arranged side by side, and a battery cell group is arranged between two adjacent liquid cooling components to liquid-cool both sides of the battery cell group respectively.

[0035] In one embodiment, the material of the plastic current collecting member can be set to be one of nylon 66+glass fiber, polyphenylene sulfide, polyphthalamide and nylon 12.

[0036] In a second aspect, an embodiment of the present invention provides a battery pack, comprising:

[0037] A liquid cooling system, the liquid cooling system comprising a plurality of liquid cooling components, the plurality of liquid cooling components being arranged side by side; and

[0038] A plurality of battery cell groups, wherein the plurality of battery cell groups are arranged side by side, and each of the battery cell groups is located between two adjacent liquid cooling components;

[0039] Wherein, the liquid cooling system is set to be the above-mentioned liquid cooling system.

[0040] Beneficial effects of the embodiments of the present invention:

[0041] In an embodiment of the present invention, a liquid cooling component in a liquid cooling system is used to liquid cool the side of a battery cell group, and the liquid cooling component includes a liquid cooling plate and a plastic current collector; the liquid cooling plate is arranged on the side of the battery cell group and includes a liquid cooling channel, and the liquid cooling plate made of metal has a high thermal conductivity, thereby ensuring the liquid cooling effect of the liquid cooling plate on the side of the battery cell group; at the same time, the liquid cooling plate is provided with a liquid inlet and a liquid outlet connected to the liquid cooling channel, and the liquid inlet and the liquid inlet pipe, as well as the liquid outlet and the liquid outlet pipe are connected by providing a plastic current collector; that is, the coolant flows through the liquid inlet pipe and the liquid inlet channel, and automatically The liquid inlet flows to the liquid cooling channel, and during the circulation of the coolant, heat is exchanged with the battery cell group, thereby achieving liquid cooling of the side of the battery cell group; the coolant flows through the liquid cooling channel and flows from the liquid outlet to the liquid outlet channel; thus, a liquid cooling circuit is formed to improve the liquid cooling effect; by injection molding the plastic collector on the liquid cooling plate and integrally arranging it with the liquid cooling plate, not only the weight of the plastic collector can be reduced, thereby reducing the overall weight of the liquid cooling system; but also the cost of the plastic collector can be reduced; and the connection strength and sealing of the plastic collector and the liquid inlet interface or the liquid outlet interface can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 is a first stereoscopic schematic diagram of a liquid cooling system provided by an embodiment of the present invention;

[0044] Figure 2 for Figure 1 Schematic diagram of the liquid cooling system in the figure;

[0045] Figure 3 for Figure 2 An enlarged schematic diagram of a local A in FIG.

[0046] Figure 4 for Figure 1A three-dimensional schematic diagram of a plastic current collecting member;

[0047] Figure 5 for Figure 4 A cross-sectional view of BB in FIG.

[0048] Figure 6 for Figure 1 A front view of the connection between the liquid cooling plate and the plastic current collector;

[0049] Figure 7 is a second stereoscopic schematic diagram of a liquid cooling system provided by an embodiment of the present invention;

[0050] Figure 8 for Figure 7 Schematic diagram of the liquid cooling system in the figure;

[0051] Fig. 9 for Figure 8 An enlarged schematic diagram of a local C in FIG.

[0052] Fig.10 for Figure 8 A three-dimensional schematic diagram of a plastic current collecting member;

[0053] Fig.11 for Fig.10 A cross-sectional view of DD in FIG.

[0054] Fig.12 for Fig.11 An enlarged schematic diagram of the local E in FIG.

[0055] Fig.13 for Figure 8 A front view of the connection between the liquid cooling plate and the plastic current collector;

[0056] Fig.14 A three-dimensional schematic diagram of a battery pack provided in an embodiment of the present invention.

[0057] The names of the components corresponding to the corresponding reference numerals in the figures are:

[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; e channel; 111a first end; 111b second end; 112 plate segment; 1121 connecting plate segment; 1122 liquid cooling plate segment; 12 plastic 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 rib; 143 limiting protrusion; 15 connecting piece; 200 battery cell group; 201 side; 300 external pipeline; F1 length direction. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the drawings; while "inside" and "outside" refer to the outline of the device.

[0060] In a first aspect, the present invention provides a liquid cooling system 100. Figure 1 , Figure 3 , Figure 7 as well as Fig.14 The liquid cooling system 100 includes at least one liquid cooling component 1, and the liquid cooling component 1 is used to liquid cool a battery cell group 200. The liquid cooling component 1 includes a liquid cooling plate 11 and a plastic current collector 12. The liquid cooling plate 11 is arranged on the side 201 of the battery cell group 200. The liquid cooling plate 11 is hollow and has a liquid cooling channel a formed therein. The liquid cooling plate 11 is provided with a liquid inlet b connected to one end of the liquid cooling channel a, and The liquid outlet c is connected to the other end of the liquid cooling channel a; the plastic collecting part 12 is injection molded on the liquid cooling plate 11 and is integrally arranged with the liquid cooling plate 11, and the plastic collecting part 12 includes a liquid inlet channel 121 and a liquid outlet channel 122, the liquid inlet channel 121 is used to connect the liquid inlet b of the liquid cooling plate 11 and the liquid inlet pipe 301, and the liquid outlet channel 122 is used to connect the liquid outlet c of the liquid cooling plate 11 and the liquid outlet pipe 302.

[0061] It can be known that in the related art, the current collector is machined from a metal part, and then the machined current collector is welded to the liquid cooling plate 11 to form a liquid cooling system 100; the metal current collector not only increases the overall weight of the liquid cooling system 100, but the machining and metal welding processes also increase the cost of the liquid cooling system 100.

[0062] In an embodiment of the present invention, the liquid cooling plate 11 includes a liquid cooling channel a, and the liquid cooling plate 11 is arranged on the side 201 of the battery cell group 200. 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 201 of the battery cell group 200.

[0063] At the same time, the liquid cooling plate 11 is provided with a liquid inlet b and a liquid outlet c connected to the liquid cooling channel a, and the liquid inlet b and the liquid inlet pipe 301, and the liquid outlet c and the liquid outlet pipe 302 are connected by setting a plastic collecting piece 12; that is, the coolant flows through the liquid inlet pipe 301 and the liquid inlet channel 121, and flows from the liquid inlet b to the liquid cooling channel a, and during the circulation of the coolant, heat exchange is performed with the battery cell group 200, thereby realizing liquid cooling of the side 201 of the battery cell group 200; the coolant flows through the liquid cooling channel a and flows from the liquid outlet c to the liquid outlet channel 122; in this way, a liquid cooling circuit is formed to improve the liquid cooling effect.

[0064] In an embodiment of the present invention, 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 the metal current collector, thereby reducing the overall weight of the liquid cooling system 100; and the plastic current collector 12 is directly injection molded on the liquid cooling plate 11, which can simplify the production and assembly process of the plastic current collector 12 compared with machining and metal welding processes, thereby having a lower cost, and further reducing the overall production cost of the liquid cooling system 100; and the plastic current collector 12 is integrally arranged with the liquid cooling plate 11 through injection molding, thereby ensuring the connection strength and sealing of the plastic current collector 12 and the liquid cooling plate 11.

[0065] The plastic current collecting member 12 is provided with a liquid inlet interface 126 and a liquid outlet interface 127 . The liquid inlet interface 126 is connected to the liquid inlet channel 121 and the liquid inlet pipeline 301 ; the liquid outlet interface 127 is connected to the liquid outlet channel 122 and the liquid outlet pipeline 302 .

[0066] The present application does not impose any specific restrictions on the number and position of the plastic current collector 12. In some embodiments, a single liquid cooling plate 11 cools two battery cell groups 200, and the two ends of the liquid cooling plate 11 are respectively provided with a liquid inlet b and a liquid outlet c, and a current collector is respectively provided on the liquid inlet b and the liquid outlet c; in other embodiments, a single liquid cooling plate 11 cools two battery cell groups 200, and the liquid inlet b and the liquid outlet c are provided on the same side of one end of the liquid cooling plate 11, and a current collector is provided on one end of the liquid cooling plate 11; in some other embodiments, a single liquid cooling plate 11 is provided in a bent manner and can cool more than three battery cell groups 200 at the same time, and the two ends of the liquid cooling plate 11 are provided on the same side, and the liquid inlet b and the liquid outlet c are respectively provided, and a current collector is respectively provided on the liquid inlet b and the liquid outlet c. No specific restrictions are imposed here, and the plastic current collector of the present application is applicable to various types of liquid cooling plates 11.

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

[0068] Taking "the two ends of the liquid cooling channel a are arranged on the same side" as an example, the present application does not impose specific restrictions on the structure of the liquid cooling channel a. In one embodiment, the liquid cooling channel a includes a first flow segment, a second flow segment, and a connecting flow segment, the first flow segment and the second flow segment are arranged in parallel and along the length direction F1 of the battery cell group 200, and in the length direction F1 of the battery cell group 200, the two ends of the first flow segment and the second flow segment on the same side are connected through the connecting flow segment, and the other two ends of the first flow segment and the second flow segment on the same side respectively correspond to form the two ends of the liquid cooling channel a.

[0069] In another embodiment, the liquid-cooling channel a includes a third flow segment and a fourth flow segment, the third flow segment and the fourth flow segment are arranged in parallel and along the length direction F1 of the battery cell group 200, and on the length direction F1 of the battery cell group 200, the two ends of the third flow segment and the fourth flow segment on the same side pass through the liquid cooling plate 11, and a connecting piece 15 is also provided on the liquid cooling plate 11 to connect the two ends of the third flow segment and the fourth flow segment on the same side, and the other two ends of the third flow segment and the fourth flow segment on the same side respectively correspond to form the two ends of the liquid cooling channel a.

[0070] The following is an example of "the liquid cooling channel a includes a third flow segment and a fourth flow segment, the two ends on the same side of the third flow segment and the fourth flow segment penetrate the liquid cooling plate 11 and are connected through the connecting piece 15, and the other two ends on the same side of the third flow segment and the fourth flow segment respectively form the two ends of the liquid cooling channel a". The two ends of the liquid cooling channel a are arranged on the same side; a connecting portion 13 is integrally formed on the liquid cooling plate 11, and the connecting portion 13 is hollow, one end of which is respectively connected to the two ends of the liquid cooling channel a, and the other end is formed with the liquid inlet b and the liquid outlet c; the plastic collector 12 is injection molded at the other end of the connecting portion 13; in this way, only one plastic collector 12 is provided on each liquid cooling plate 11, which can minimize the number of plastic collectors 12; at the same time, the plastic collector 12 is injection molded on the connecting portion 13, which can make the plastic collector 12 easier to injection mold.

[0071] Following the above examples, please refer to Figure 2 and Figure 3In the length direction F1 of the battery cell group 200, the liquid cooling plate 11 has a first end 111a and a second end 111b opposite to each other, one end of the third flow segment passes through the second end 111b, and one end of the fourth flow segment on the same side passes through the second end 111b, and the connecting piece 15 is arranged at the second end 111b to connect the third flow segment and the fourth flow segment.

[0072] See also Figures 1 to 6 In the first embodiment of the present application, the two ends of the liquid-cooling channel a are arranged close to the first end 111a; the first end 111a is provided with a channel e connecting the two ends of the liquid-cooling channel a, and the ends of the channel e form the liquid inlet b and the liquid outlet c; wherein the connecting portion 13 includes the first end 111a, and the plastic collecting part 12 is injection molded at the first end 111a.

[0073] In the first embodiment of the present application, both ends of the liquid cooling channel a are arranged close to the first end 111a, and the liquid inlet b and the liquid outlet c connected to the liquid cooling channel a are formed on the first end 111a. The first end 111a forms the connecting portion 13, and the plastic collecting part 12 is directly injection molded on the liquid cooling plate 11.

[0074] Specifically, in the first embodiment, when the plastic current collecting member 12 is injection molded on the first end portion 111a, one end of the plastic current collecting member 12 is sleeved on the outer side of the first end portion 111a. Figure 6 , in the length direction F1 of the battery cell group 200, wherein:

[0075] The plug-in length H1 between the first end 111a and the plastic current collecting member 12 is set to H1, and 2mm≤H1≤200mm; when the plug-in length H1 between the plastic current collecting member 12 and the liquid cooling plate 11 is less than 2mm, the connection strength between the plastic current collecting member 12 and the liquid cooling plate 11 is small, and the plastic current collecting member 12 is very easy to fall off from the liquid cooling plate 11; when the plug-in length H1 between the plastic current collecting member 12 and the liquid cooling plate 11 is greater than 200mm, the size of the plastic current collecting member 12 needs to be made larger, thereby increasing the overall size of the liquid cooling component 1; setting the plug-in length H1 between the first end 111a and the plastic current collecting member 12 to 2mm~200mm not only ensures that the overlap length of the plastic current collecting member 12 and the liquid cooling plate 11 is sufficient, thereby improving the connection strength between the plastic current collecting member 12 and the liquid cooling plate 11; and there is no need to increase the size of the plastic current collecting member 12, thereby controlling the overall size of the liquid cooling component 1.

[0076] The plug-in length of the first end 111a and the plastic current collecting member 12 is set to H1, the length of the connecting portion 13 is set to H2, and 1mm≤H2-H1≤50mm; it can be known that before the plastic current collecting member 12 is injection-molded on the first end 111a, it is necessary to first perform surface treatment on the position close to the first end 111a on the outer wall 141 of the liquid cooling plate 11, so as to form the connecting portion 13; after the first end 111a is plugged into the plastic current collecting member 12, the surface-treated position will be partially exposed outside the plastic current collecting member 12, and the exposed size is set to 1mm~50mm; when the length difference is less than 1mm When the length difference is greater than 50 mm, the surface-treated area on the liquid cooling plate 11 is larger, which increases the process cost. The length exceeding the plastic current collector 12 is set to 1 mm to 50 mm, which not only ensures that the plastic current collector 12 overlaps the surface-treated area on 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 either one or at the same time. Specifically, in one embodiment, the above two technical features are set at the same time.

[0078] The present application does not impose any specific limitation on the plug-in length H1 between the connection portion 13 and the plastic current collecting member 12 . The plug-in length H1 between the connection portion 13 and the plastic current collecting member 12 can be set to 2 mm, 10 mm, 20 mm, 50 mm, 100 mm, and 200 mm.

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

[0080] See also Figures 7 to 13 In the second embodiment of the present application, the two ends of the liquid-cooling channel a are arranged on the same side and penetrate the first end 111a; a connecting tube 14 is fixedly connected to the first end 111a, one end of the connecting tube 14 is respectively connected to the two ends of the liquid-cooling channel a, and the other end of the connecting tube 14 forms the liquid inlet b and the liquid outlet c; wherein, the connecting portion 13 includes the connecting tube 14, and the plastic collecting part 12 is injection molded at the other end of the connecting tube 14.

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

[0082] Specifically, in the second embodiment, the plastic current collecting member 12 is sleeved on the outer side of the connecting pipe 14, see Fig.12 , in the length direction F1 of the battery cell group 200, wherein:

[0083] The plug-in length H3 of the connecting tube 14 and the plastic current collecting part 12 is 2mm≤H3≤200mm; when the plug-in length H3 of the plastic current collecting part 12 and the connecting tube 14 is less than 2mm, the connection strength between the plastic current collecting part 12 and the connecting tube 14 is small, and the plastic current collecting part 12 is very easy to fall off from the connecting tube 14; when the plug-in length H3 of the plastic current collecting part 12 and the connecting tube 14 is greater than 200mm, the size of the plastic current collecting part 12 needs to be made larger, thereby increasing the overall size of the liquid cooling component 1; setting the plug-in length H3 of the plastic current collecting part 12 and the connecting tube 14 to 2mm~200mm not only ensures that the overlap length of the plastic current collecting part 12 and the connecting tube 14 is sufficient, thereby improving the connection strength between the plastic current collecting part 12 and the connecting tube 14; and there is no need to increase the size of the plastic current collecting part 12, thereby controlling the overall size of the liquid cooling component 1.

[0084] The plug-in length of the connecting tube 14 and the plastic current collecting member 12 is set to H3, the length of the connecting tube 14 is set to H4, and 5mm≤H4-H3≤200mm; when the length H4-H3 of the connecting tube 14 exposed outside the plastic current collecting member 12 is less than 5mm, the welding space between the connecting tube 14 and the liquid cooling plate 11 is insufficient; when the length H4-H3 of the connecting tube 14 exposed outside the plastic current collecting member 12 is greater than 200mm, the size of the connecting tube 14 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1; setting the length H4-H3 of the connecting tube 14 exposed outside the plastic current collecting member 12 to 5mm~200mm not only ensures that there is enough welding space between the connecting tube 14 and the liquid cooling plate 11, but also can reasonably control the size of the connecting tube 14.

[0085] The distance between the plastic current collecting part 12 and the first end 111a is set to H5, and H5 is greater than or equal to 3 mm. It can be known that one end of the connecting tube 14 is sleeved on the first end 111a, and the plastic current collecting part 12 is injection molded at the other end of the connecting tube 14. Usually, the connecting tube 14 and the first end 111a are laser welded, and the distance H5 between the plastic current collecting part 12 and the first end 111a is set to be greater than or equal to 3 mm, so that there is a sufficient distance between the first end 111a and the plastic current collecting part 12, thereby providing sufficient welding space for the connecting tube 14.

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

[0087] The present application does not impose any specific limitation on the plug-in length H3 between the connecting tube 14 and the plastic current collecting member 12 . The plug-in length H3 between the connecting tube 14 and the plastic current collecting member 12 can be set to 2 mm, 10 mm, 20 mm, 50 mm, 100 mm and 200 mm.

[0088] The present application does not impose any specific limitation on the length H4-H3 of the connecting tube 14 exposed outside the plastic current collecting member 12. The length H4-H3 of the connecting tube 14 exposed outside the plastic current collecting member 12 can be set to 5 mm, 10 mm, 20 mm, 50 mm, 100 mm and 200 mm.

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

[0090] In one embodiment, see Fig. 9 The outer wall 141 of the connecting tube 14 is provided with a limiting rib 142, and the plastic current collecting part 12 is sleeved on the outer side of the connecting tube 14 and abuts against the limiting rib 142; the limiting rib 142 is provided to limit the plug-in length H3 between the connecting tube 14 and the plastic current collecting part 12, thereby preventing the plastic current collecting part 12 from exceeding the maximum plug-in length during injection molding.

[0091] In one embodiment, a limiting protrusion 143 is protrudingly provided on the inner wall of the connecting tube 14, and the first end portion 111a is inserted into one end of the connecting tube 14 and abuts against the limiting protrusion 143; by providing the limiting protrusion 143, the plug-in position of the connecting tube 14 and the first end portion 111a is limited, thereby preventing the first end portion 111a from being too close to the plastic current collecting component 12 due to the large plug-in length with the connecting tube 14, thereby ensuring that there is a sufficient distance between the first end portion 111a and the plastic current collecting component 12, thereby providing sufficient welding space for the connecting tube 14.

[0092] Based on the above first and second embodiments, please refer to Fig.11 and Fig.12 A step groove 123 is provided on the plastic current collecting part 12. In the direction away from the notch 123a of the step groove 123, the step groove 123 includes a first groove section 1231 and a second groove section 1232 with decreasing groove diameters. A step surface 1233 is formed at the connection between the first groove section 1231 and the second groove section 1232. Two independent cavities 1234 are formed in the second groove section 1232 to respectively correspond to form the liquid inlet channel 121 and the liquid outlet channel 122; the connecting portion 13 is inserted into the notch 123a of the step groove 123 and abuts against the step surface 1233. That is to say, the first groove section 1231 and the second groove section 1232 are formed in the plastic current collecting part 12, the first groove section 1231 forms the liquid inlet channel 121 and the liquid outlet channel 122, and the second groove section 1232 is sleeved on the outer side of the connecting part 13, which can further reduce the difficulty of injection molding of the plastic current collecting part 12.

[0093] Specifically, a step surface 1233 is formed at the connection between the first groove section 1231 and the second groove section 1232, and the connecting portion 13 is inserted into the notch 123a of the step groove 123 and abuts against the step surface 1233; by setting the step groove 123 and the step surface 1233, the plug-in length H3 of the connecting tube 14 and the plastic current collecting part 12 is limited, thereby preventing the plastic current collecting part 12 from exceeding the maximum plug-in length during injection molding.

[0094] Furthermore, in one embodiment, an annular groove 1235 is provided on the step surface 1233, and the width of the annular groove 1235 is smaller than the wall thickness of the connecting portion 13. The provision of the annular groove 1235 makes the interior of the plastic current collecting member 12 hollow, which can further reduce the weight of the plastic current collecting member 12, thereby further reducing the overall weight of the liquid cooling system 100.

[0095] It can be known that in the first and second embodiments described above, 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 tube 14; in order to improve the connection strength of the plastic current collector 12, it is necessary to perform surface treatment on the liquid cooling plate 11 or the connecting tube 14. Usually, the metal surface is subjected to nano-processing, plasma cleaning, oxidation treatment, passivation or anodization, so as to improve the connection strength of the plastic current collector 12.

[0096] After the liquid cooling plate 11 or the connecting tube 14 is surface treated, the other end of the connecting portion 13 extends in a direction away from the liquid cooling plate 11, and in the direction away from the liquid cooling plate 11, the outer diameter of the connecting portion 13 is gradually reduced; the plastic current collecting member 12 is sleeved on the outside of the connecting portion 13; in this way, the connection strength between the plastic current collecting member 12 and the connecting portion 13 can be improved.

[0097] The present application does not impose any specific restrictions on the material of the plastic current collector 12. The material of the plastic current collector 12 can be set to one of PA66+GF (nylon 66 plus glass fiber), PPS (full name in English: Polyphenylene Sulfide, Chinese abbreviation: polyphenylene sulfide), PPE (full name in English: 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 the density of nylon material is relatively small, which can improve the overall energy density of the battery pack 1000.

[0098] In one embodiment, at least part of the side d of the liquid cooling plate 11 is in contact with the side 201 of the battery cell group 200 and the shape is adapted thereto; the side d of the liquid cooling plate 11 is in contact with the side 201 of the battery cell group 200 and the shape is adapted thereto. Thus, the contact area between 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 increased.

[0099] What we know is that the mainstream types of battery cells on the market currently include cylindrical cells, square cells and soft-pack cells. Among them, the 4680 cylindrical battery has higher energy density, better safety and stability, and higher economy after grouping, and is expected to become the development trend of electric vehicle batteries.

[0100] Taking "the battery cells in the battery cell group 200 are configured as cylindrical battery cells" as an example, the liquid cooling plate 11 is configured as a serpentine tube or a metal harmonica tube; in this way, the serpentine tube or the metal harmonica tube contacts the side surface 201 of the cylindrical battery cell for heat exchange, and the contact area between the serpentine tube or the metal harmonica tube and the cylindrical battery cell is large, so that the cooling efficiency of the serpentine tube or the metal harmonica tube is high, thereby making the pressure drop of the liquid cooling system 100 small.

[0101] The present application does not impose any specific restrictions on the structure of the liquid cooling plate 11. For example, "the liquid cooling plate 11 is configured as a serpentine tube". 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 spliced ​​with each other, the plurality of plate segments 112 include connecting plate segments 1121 located at both ends of the liquid cooling plate 11, and a plurality of liquid cooling plate segments 1122 located between the two connecting plate segments 1121, the two connecting plate segments 1121 are configured as straight plate segments 112, each of the liquid cooling plate segments 1122 is in contact with the side surface 201 of a battery cell in the battery cell group 200, and the shape thereof is adapted; the liquid inlet b and the liquid outlet c are configured on the same side and are configured on one of the connecting plate segments 1121, and the plastic current collecting member 12 is correspondingly injection molded on the connecting plate segment 1121.

[0102] In this embodiment, the liquid cooling plate segment 1122 is in contact with the side surface 201 of a battery cell in the battery cell group 200 and has a matching shape, thereby ensuring that the liquid cooling plate segment 1122 has a larger contact area with the battery cell, thereby improving 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 collector 12 is easier to be injection molded on the connecting plate segment 1121.

[0103] Usually, there are multiple battery cell groups 200. In order to ensure that all the battery cell groups 200 can be liquid-cooled, in one embodiment, the liquid cooling system 100 includes multiple liquid cooling components 1. The multiple liquid cooling components 1 are arranged side by side, and one battery cell group 200 is arranged between two adjacent liquid cooling components 1 to liquid-cool the two sides of the battery cell group 200 respectively. With this arrangement, both sides of each battery cell group 200 can be liquid-cooled by the liquid cooling component 1, which not only makes the structural arrangement of the liquid cooling system 100 more reasonable, but also can further improve the liquid cooling effect of the liquid cooling system 100.

[0104] It can be understood that the present invention does not limit the connection method of the multiple liquid cooling components 1; the multiple liquid cooling components 1 can be arranged in parallel or in series; preferably, the multiple liquid cooling components 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 further provide a battery pack 1000. Fig.14 , the battery pack 1000 includes a liquid cooling system 100 and a plurality of battery cell groups 200; the liquid cooling system 100 includes a plurality of liquid cooling components 1, and the plurality of liquid cooling components 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 components 1. It should be noted that the liquid cooling system 100 is configured as the above-mentioned liquid cooling system 100, that is, the liquid cooling system 100 has all the technical features of the above-mentioned liquid cooling system 100, that is, the battery pack 1000 includes all the embodiments of the above-mentioned liquid cooling system 100.

[0106] The liquid cooling assembly 1 includes a liquid cooling plate 11 and a plastic current collecting part 12. The liquid cooling plate 11 includes a liquid cooling channel a. The liquid cooling plate 11 is arranged on the side 201 of the battery cell group 200. 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 201 of the battery cell group 200.

[0107] At the same time, the liquid cooling plate 11 is provided with a liquid inlet b and a liquid outlet c connected to the liquid cooling channel a, and the plastic collecting piece 12 is provided to connect the liquid inlet b and the liquid inlet pipe 301, and the liquid outlet c and the liquid outlet pipe 302; that is, the coolant flows through the liquid inlet pipe 301 and the liquid inlet channel 121, and flows from the liquid inlet b to the liquid cooling channel a, and during the circulation of the coolant, heat exchange is performed with the battery cell group 200, thereby achieving liquid cooling of the side 201 of the battery cell group 200; the coolant flows through the liquid cooling channel a and flows from the liquid outlet c to the liquid outlet channel 122; in this way, a liquid cooling circuit is formed to improve the liquid cooling effect.

[0108] 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 the metal current collector, thereby reducing the overall weight of the liquid cooling system 100; and the plastic current collector 12 is directly injection molded on the liquid cooling plate 11, which can simplify the production and assembly process of the plastic current collector 12 compared with machining and metal welding processes, thereby having a lower cost, and further reducing the overall production cost of the liquid cooling system 100; and the plastic current collector 12 is integrally arranged with the liquid cooling plate 11 through injection molding, thereby ensuring the connection strength and sealing between the plastic current collector 12 and the liquid cooling plate 11.

[0109] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A liquid cooling system, characterized in that: At least one liquid cooling component is included, and the liquid cooling component is used to liquid cool a battery cell group, and the liquid cooling component includes: A liquid cooling plate, the liquid cooling plate is arranged on the side of the battery cell group, the liquid cooling plate is hollow and has a liquid cooling channel formed therein, and the liquid cooling plate is provided with a liquid inlet connected to one end of the liquid cooling channel and a liquid outlet connected to the other end of the liquid cooling channel; and, A plastic current collecting part, which is injection molded on the liquid cooling plate and is integrally arranged with the liquid cooling plate. The plastic current collecting part includes a liquid inlet channel and a liquid outlet channel. The liquid inlet channel is used to connect the liquid inlet and the liquid inlet pipeline of the liquid cooling plate, and the liquid outlet channel is used to connect the liquid outlet and the liquid outlet pipeline 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; The liquid cooling plate is integrally formed with a connecting portion, the connecting portion is hollow, one end of which is respectively connected to the two ends of the liquid cooling channel, and the other end of which is formed with the liquid inlet and the liquid outlet; The plastic current collecting piece is injection molded at the other end of the connecting portion.

3. The liquid cooling system according to claim 2, characterized in that: In the length direction of the battery cell group, the liquid cooling plate has a first end, and both ends of the liquid cooling channel are arranged close to the first end; The first end portion is provided with a channel connecting the two ends of the liquid cooling channel, and the ends of the channel form the liquid inlet and the liquid outlet; Wherein, the connecting portion includes the first end portion, and the plastic current collecting member is injection molded on 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 portion in the length direction of the battery cell group, wherein: The insertion length between the first end and the plastic current collecting member is set to H1, and 2mm≤H1≤200mm; and / or, The plug-in length between the first end and the plastic current collecting member is set to H1, the length of the connecting portion is set to H2, and 1mm≤H2-H1≤50mm.

5. The liquid cooling system according to claim 2, characterized in that: In the length direction of the battery cell group, the liquid cooling plate has a first end, both ends of the liquid cooling channel pass through the first end, a connecting tube is fixedly connected to the first end, one end of the connecting tube is respectively connected to both ends of the liquid cooling channel, and the other end of the connecting tube forms the liquid inlet and the liquid outlet; Wherein, the connecting portion includes the connecting tube, and the plastic current collecting piece is injection molded at the other end of the connecting tube.

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 in the length direction of the battery cell group, wherein: The plug-in length between the connecting pipe and the plastic current collecting piece is set to H3, and 2mm≤H3≤200mm; and / or, The plug-in length between the connecting tube and the plastic current collecting member is set to H3, the length of the connecting tube is set to H4, and 5mm≤H4-H3≤200mm; and / or, The distance between the plastic current collecting member and the first end is set to H5, and H5 is greater than or equal to 3 mm.

7. The liquid cooling system according to claim 5, characterized in that: The outer wall of the connecting pipe is provided with a limiting convex rib; The plastic current collecting piece is sleeved on the outer side of the connecting pipe and abuts against the limiting convex 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 portion is inserted into one end of the connecting pipe and abuts against the limiting protrusion.

9. The liquid cooling system according to claim 2, characterized in that: The plastic current collecting member is provided with a step groove, and in the direction away from the notch of the step groove, the step groove includes a first groove section and a second groove section with decreasing groove diameters, a step surface is formed at the connection between the first groove section and the second groove section, and two independent cavities are formed in the second groove section to respectively correspond to form the liquid inlet flow channel and the liquid outlet flow channel; The connecting portion is inserted into the notch of the step groove and abuts against the step surface.

10. The liquid cooling system according to claim 9, characterized in that: The step surface is provided with an annular groove, and the width of the annular groove is smaller than the wall thickness of the connecting portion.

11. The liquid cooling system according to claim 2, characterized in that: The other end of the connecting portion extends in a direction 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.

12. The liquid cooling system according to any one of claims 2 to 11, characterized in that: The side surface of the liquid cooling plate is at least partially in contact with the side surface of the battery cell group and has a matching shape.

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: In the length direction of the battery cell group, the liquid cooling plate includes a plurality of plate segments spliced ​​with each other, the plurality of plate segments include connecting plate segments located at both ends of the liquid cooling plate, and a plurality of liquid cooling plate segments located between two connecting plate segments, the two connecting plate segments are configured as straight plate segments, and each of the liquid cooling plate segments is in contact with the side surface of a battery cell in the battery cell group and has a matching shape; The liquid inlet and the liquid outlet are arranged on the same side and on one of the connecting plate sections, and the plastic current collecting piece is correspondingly injection-molded on the connecting plate section.

15. The liquid cooling system according to any one of claims 2 to 11, characterized in that: The liquid cooling system comprises a plurality of the liquid cooling components, and the plurality of the liquid cooling components are arranged side by side. A battery cell group is arranged between two adjacent liquid cooling components to respectively liquid cool the two sides of the battery cell group.

16. The liquid cooling system according to claim 1, characterized in that: The material of the plastic current collecting member can be set to 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, the liquid cooling system comprising a plurality of liquid cooling components, the plurality of liquid cooling components being arranged side by side; and A plurality of battery cell groups, wherein the plurality of battery cell groups are arranged side by side, and each of the battery cell groups is located between two adjacent liquid cooling components; Wherein, the liquid cooling system is configured as a liquid cooling system as described in any one of claims 1-16.

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