Liquid cooling plate assembly

Abstract

The present application discloses a liquid cooling plate assembly, comprising a harmonica-shaped tube, current collectors and nano injection molded parts, wherein the harmonica-shaped tube comprises first connecting ends, and a plurality of nanopores are formed on at least a part of the surface of each first connecting end; each current collector comprises a second connecting end, and the second connecting end is connected to the corresponding first connecting end; each nano injection molded part is arranged at the joint of the first connecting end and the second connecting end, the nano injection molded part fixedly covers the first connecting end and the second connecting end, and the nano injection molded part fills the nanopores formed at the first connecting end. The liquid cooling plate assembly of the present application is used for improving the fixing and sealing effect of the current collectors and the harmonica-shaped tube, and reducing the sealing and fixing cost of the current collectors and the harmonica-shaped tube.

Description

A liquid cooling plate assembly

[0001] This application claims priority to Chinese Patent Application No. 2024207435408, filed on April 11, 2024, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery cooling, for example, to a liquid cooling plate assembly. BACKGROUND

[0003] In related technologies, a battery generates heat when running. To avoid the heat generated by the battery from accumulating and affecting the battery, the battery needs to be cooled. One way to cool the battery in related technologies is to use a liquid cooling plate assembly to cool the battery. The liquid cooling plate assembly generally includes a concertina tube and a current collector. The concertina tube is used to absorb the heat generated by the battery, and the concertina tube is connected to the current collector. The current collector is used to guide the cooling liquid into the concertina tube or guide the cooling liquid out of the concertina tube after absorbing heat. To avoid leakage of the cooling liquid at the connection between the concertina tube and the current collector, the connection between the concertina tube and the current collector needs to be sealed and fixed.

[0004] In related technologies, the connection between the current collector and the concertina tube is fixed by welding. The material cost and processing cost required by the welding fixing method are high. In addition, the yield of conventional welding is low. If the connection between the current collector and the concertina tube is not welded well, the cooling liquid may leak, which will affect the operation of the battery and the cooling effect of the concertina tube. In addition, the leakage of the cooling liquid may also cause thermal runaway of the battery pack, which may cause serious safety hazards.

[0005] SUMMARY

[0006] The purpose of the present application is to provide a liquid cooling plate assembly to improve the sealing and fixing effect between the current collector and the concertina tube and reduce the sealing and fixing cost of the current collector and the concertina tube.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] A liquid cooling plate assembly, comprising:

[0009] The concertina tube includes a first connection end, and at least a portion of the surface of the first connection end is formed with a plurality of nano micropores;

[0010] The current collector includes a second connection end, and the second connection end is connected to the first connection end;

[0011] A nano-injection part is arranged at the connection between the first connecting end and the second connecting end, the nano-injection part is fixed to cover the first connecting end and the second connecting end, and the nano-injection part fills the nano-pores formed by the first connecting end.

[0012] In some optional embodiments, the current collector is a metal current collector, at least a part of the surface of the second connecting end is formed with a plurality of nano-pores, and the nano-injection part fills the nano-pores formed by the second connecting end.

[0013] In some optional embodiments, the second connecting end is provided with at least a part of a liquid supply chamber, and a part of the first connecting end extends into the liquid supply chamber, and the part of the first connecting end exposed from the liquid supply chamber is formed with the nano-pores.

[0014] In some optional embodiments, the current collector comprises a second connecting part and a first connecting part fixedly connected with the second connecting part, the second connecting part forms the second connecting end, and the first connecting part is provided with a connecting port in communication with the outside.

[0015] In some optional embodiments, the current collector further comprises a metal part and a plastic part connected with each other, the plastic part forms the second connecting end adjacent to one end of the harmonica tube, and the plastic part and the nano-injection part form an integrated structure.

[0016] In some optional embodiments, one end of the metal part connected with the plastic part is formed with a plurality of nano-pores, the plastic part fills the nano-pores formed by the metal part and is fixedly connected with the metal part.

[0017] In some optional embodiments, the metal part comprises a first connecting part, and the first connecting part is provided with a connecting port in communication with the outside.

[0018] In some optional embodiments, the current collector is a plastic current collector, a part of the current collector covering the first connecting end forms the second connecting end, and the nano-injection part and the current collector form an integrated structure.

[0019] In some optional embodiments, the harmonica tube is provided with a first connecting end at each of opposite ends, a pair of current collectors are arranged, the pair of current collectors are connected with the pair of first connecting ends one by one, and at least one current collector is connected with at least one first connecting end through the nano-injection part.

[0020] In some optional embodiments, the pair of current collectors are of the same type or different types, and the type of the current collector is one of a metal current collector, a plastic current collector, or a combined current collector with a metal part and a plastic part.

[0021] The liquid cooling plate assembly provided by the application has at least the following advantages:

[0022] By connecting the first connecting end and the second connecting end through the nano injection part, the sealing and fixing of the harmonica tube and the current collector are realized, which can effectively improve the sealing effect between the harmonica tube and the current collector; and the material cost and manufacturing cost of the nano injection part are lower than the material cost and manufacturing cost of welding, which can effectively reduce the sealing and fixing cost of the current collector and the harmonica tube. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is a structural schematic diagram of a liquid cooling plate assembly according to an embodiment of the application;

[0024] Fig. 2 is a structural schematic diagram of a liquid cooling plate assembly according to another embodiment of the application;

[0025] Fig. 3 is a partial sectional view of a liquid cooling plate assembly according to an embodiment of the application when a metal current collector is used;

[0026] Fig. 4 is a partial sectional view of a liquid cooling plate assembly according to another embodiment of the application when a metal current collector is used;

[0027] Fig. 5 is a partial sectional view of a liquid cooling plate assembly according to an embodiment of the application when a plastic current collector is used;

[0028] Fig. 6 is a partial sectional view of a liquid cooling plate assembly according to another embodiment of the application when a plastic current collector is used;

[0029] Fig. 7 is a partial sectional view of a liquid cooling plate assembly according to an embodiment of the application when a combined current collector is used;

[0030] Fig. 8 is a partial sectional view of a liquid cooling plate assembly according to another embodiment of the application when a combined current collector is used.

[0031] In the drawings: 1, harmonica tube; 11, first connecting end; 12, flow cavity; 2, current collector; 21, second connecting end; 22, second connecting part; 221, liquid supply chamber; 23, first connecting part; 231, connecting port; 24, metal part; 25, plastic part; 3, nano injection part. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the figures, and thus description of the same will be simplified or omitted.

[0033] The expression of position and direction described in the present application is illustrated by taking the drawings as an example, but changes can also be made as needed, and the changes are included in the protection scope of the present application.

[0034] As shown in FIG. 1 and FIG. 2, the present application provides a liquid cooling plate assembly, which comprises a harmonica tube 1, a current collector 2 and a nano injection molding part 3.

[0035] Referring to FIG. 3, the harmonica tube 1 is provided with a flow cavity 12 for flowing of cooling liquid. At least one end of the flow cavity 12 penetrates the harmonica tube 1, and the end of the flow cavity 12 penetrating the harmonica tube 1 can be used for inputting or outputting cooling liquid. In some optional embodiments, the opposite ends of the flow cavity 12 both penetrate the harmonica tube 1, and the opposite ends of the flow cavity 12 can be used for inputting or outputting cooling liquid, respectively, for example, the cooling liquid can flow into the flow cavity 12 from one end and flow out of the flow cavity 12 from the other end. The harmonica tube 1 can be arranged near or abutting to the battery to be cooled, and the cooling liquid in the harmonica tube 1 can be used to absorb the heat of the battery to achieve cooling of the battery. The harmonica tube 1 is made of a material with good thermal conductivity, for example, the harmonica tube 1 is made of aluminum alloy material. The harmonica tube 1 can be a thin hollow plate structure. The cooling liquid can be cooling liquid, or a liquid with large specific heat capacity such as water.

[0036] The harmonica tube 1 comprises a first connecting end 11. The first connecting end 11 is used for connecting with the current collector 2 to input or output cooling liquid. The first connecting end 11 can be the end of the harmonica tube 1 penetrated by the flow cavity 12, and the first connecting end 11 can be provided as one or more. For example, when the flow cavity 12 only penetrates one end of the harmonica tube 1, the first connecting end 11 can be provided as one; when the opposite ends of the flow cavity 12 both penetrate the harmonica tube 1, the first connecting end 11 can be provided as two, and the two first connecting ends 11 correspond to the opposite ends of the harmonica tube 1 penetrated by the flow cavity 12. At least a part of the surface of the first connecting end 11 can form a plurality of nano micropores. The nano micropore can be a tiny hole with a pore size of tens to hundreds of nanometers, for example, a tiny hole with a pore size of 10-300 μm.

[0037] The current collector 2 is connected with the harmonica tube 1 and is used for inputting cooling liquid to the harmonica tube 1 or receiving cooling liquid flowing out of the harmonica tube 1. The current collector 2 can comprise a second connecting part 22 and a first connecting part 23 fixedly connected with the second connecting part 22. In some specific embodiments, as shown in FIG. 2, the axial direction of the first connecting part 23 can be perpendicular to the thickness direction of the second connecting part 22. In some specific embodiments, as shown in FIG. 1, the axial direction of the first connecting part 23 can be parallel to the thickness direction of the second connecting part 22.

[0038] The first connecting part 23 is formed with a connecting port 231 in communication with the outside, and the second connecting part 22 is formed with a liquid supply chamber 221 for communicating with the flow cavity 12 of the harmonica tube 1. The inside of the current collector 2 is hollow, and the connecting port 231 can be in communication with the liquid supply chamber 221. The connecting port 231 can be in communication with the pipeline outside for the flow of the cooling liquid to receive the cooling liquid in the pipeline outside or output the cooling liquid to the pipeline outside. When the cooling liquid enters the harmonica tube 1, the cooling liquid flows into the current collector 2 from the connecting port 231, and flows into the flow cavity 12 of the harmonica tube 1 from the liquid supply chamber 221 of the current collector 2 to absorb the heat emitted by the battery; when the cooling liquid is output from the harmonica tube 1, the cooling liquid after absorbing heat flows into the liquid supply chamber 221 of the current collector 2 from the harmonica tube 1, and flows to the pipeline outside from the connecting port 231 of the current collector 2 to discharge the cooling liquid from the liquid cooling plate assembly.

[0039] The current collector 2 can be provided with a second connecting end 21. The second connecting end 21 is connected with the first connecting end 11 to realize the connection of the current collector 2 with the harmonica tube 1. In addition, the number of current collectors 2 can be one or more, and each current collector 2 is formed with a second connecting end 21. When the first connecting end 11 of the harmonica tube 1 is provided as one, the current collector 2 can be provided as one and connected with the first connecting end 11; when the first connecting end 11 of the harmonica tube 1 is provided as a plurality, the current collector 2 can be provided as a plurality, and the number of the plurality of current collectors 2 can be the same as the number of the plurality of first connecting ends 11, and can be connected one by one.

[0040] The second connecting end 21 can be formed on the second connecting part 22 of the current collector 2, and therefore the second connecting end 21 has at least part of the liquid supply chamber 221. The first connecting end 11 can extend into the liquid supply chamber 221 at the second connecting end 21, and the part of the first connecting end 11 exposed to the liquid supply chamber 221 is formed with a plurality of nano-micro-holes. It should be noted that the nano-micro-holes provided on the first connecting end 11 can all be located on the part of the first connecting end 11 exposed to the liquid supply chamber 221; or part of the nano-micro-holes provided on the first connecting end 11 are located on the part of the first connecting end 11 exposed to the liquid supply chamber 221, and the other part of the nano-micro-holes are located on the part of the first connecting end 11 extending into the liquid supply chamber 221.

[0041] The nano-injection part 3 is arranged at the connection between the first connecting end 11 and the second connecting end 21, and the nano-injection part 3 can fixedly cover the first connecting end 11 and the second connecting end 21 to realize the sealed fixed connection of the first connecting end 11 and the second connecting end 21. When the nano-injection part 3 covers the first connecting end 11, the nano-injection part 3 can fill the nano-micro-holes formed on the first connecting end 11 to enhance the bonding force between the nano-injection part 3 and the first connecting end 11, enhance the connection stability of the nano-injection part 3 and the first connecting end 11, and improve the sealing and fixing effect of the nano-injection part 3.

[0042] It should be noted that the specific structure and shape of the harmonica tube 1 and the current collector 2 are only part of the possible structures and shapes of the harmonica tube 1 and the current collector 2 selected for ease of description. The harmonica tube 1 and the current collector 2 in this application are not limited to the above structures and shapes. Other structures and shapes of the harmonica tube 1 can be used to form the first connecting end 11, and other structures and shapes of the current collector 2 can be used to form the second connecting end 21. Then, the nano-injection part 3 is arranged at the connection between the first connecting end 11 and the second connecting end 21, so as to realize the sealed and fixed connection of the harmonica tube 1 and the current collector 2 with other structures and shapes.

[0043] The nano-injection part 3 can be formed at the connection between the first connecting end 11 and the second connecting end 21 in the form of nano-injection. The material of the nano-injection part 3 can be one or more of PPS (Polyphenylene sulfide, polyphenylene sulfide) plastic, LCP (Liquid Crystal Polymer, liquid crystal polymer) plastic, PEEK (Polyetheretherketone, polyether ether ketone) plastic, PBT (Polybutylene Terephthalate, polybutylene terephthalate) plastic, and PI (Polyimide, polyimide) plastic. When the harmonica tube 1 is provided with only one first connecting end 11, the first connecting end 11 is sealed and fixedly connected to the second connecting end 21 through the nano-injection part 3. When the harmonica tube 1 is provided with two first connecting ends 11, only one first connecting end 11 can be sealed and fixedly connected to the second connecting end 21 through the nano-injection part 3, and the other first connecting end 11 can be connected to the second connecting end 21 in other sealed and fixed manner, such as being sealed and fixedly connected to the second connecting end 21 by welding. In some optional embodiments, when the harmonica tube 1 is provided with two first connecting ends 11, the two first connecting ends 11 are respectively sealed and fixedly connected to the corresponding second connecting ends 21 through one nano-injection part 3.

[0044] By using the nano-injection part 3 to be injection molded at the connection between the first connecting end 11 and the second connecting end 21, the sealing between the first connecting end 11 and the second connecting end 21 can be effectively improved. The nano-injection process has excellent sealing performance, and the material strength of the nano-injection part 3 formed is high, which can form an excellent sealing and fixing effect between the first connecting end 11 and the second connecting end 21, and further realize a better sealing and fixing between the current collector 2 and the harmonica tube 1, thereby improving the yield of the liquid cooling plate assembly. Moreover, the nano-injection process has lower cost than the welding process, which can reduce the sealing and fixing cost of the current collector 2 and the harmonica tube 1.

[0045] Referring to FIGS. 3 and 4, in some embodiments, the current collector 2 can adopt a metal current collector, for example, the current collector 2 is an aluminum alloy current collector 2. To improve the connection effect of the second connecting end 21 of the current collector 2 and the nano-injection part 3, at least a part of the surface of the second connecting end 21 can form a plurality of nano-pores. The nano-injection part 3 can fill the nano-pores formed by the second connecting end 21 to enhance the bonding force between the nano-injection part 3 and the second connecting end 21, enhance the connection stability of the nano-injection part 3 and the second connecting end 21, and improve the sealing and fixing effect of the nano-injection part 3.

[0046] When it is necessary to connect the current collector 2 and the mouthpiece tube 1, the surface treatment can be performed on the mouthpiece tube 1 and the current collector 2, so that the surface of the first connecting end 11 of the mouthpiece tube 1 forms a plurality of nano-pores, and the surface of the second connecting end 21 of the current collector 2 forms a plurality of nano-pores. The first connecting end 11 of the mouthpiece tube 1 is inserted into the second connecting end 21 of the current collector 2, and then the connected mouthpiece tube 1 and current collector 2 are buried in a prefabricated injection mold for nano-injection, so as to form a nano-injection part 3 at the connection between the first connecting end 11 and the second connecting end 21. The injection mold has a cavity adapted to the size and shape of the liquid cooling plate assembly, so that when the connected mouthpiece tube 1 and current collector 2 are placed in the cavity of the injection mold, the mouthpiece tube 1 and current collector 2 occupy part of the cavity, and the space corresponding to the nano-injection part 3 in the cavity of the injection mold is not occupied. Therefore, when nano-injection is performed, the liquid plastic flows into the cavity of the injection mold, and then fills the space corresponding to the nano-injection part 3 in the cavity, and after the plastic cools down, the nano-injection part 3 is formed, which is fixedly attached to the current collector 2 and the mouthpiece tube 1, fills the nano-pores on the second connecting end 21 of the current collector 2 and the first connecting end 11 of the mouthpiece tube 1, and seals and fixes the current collector 2 and the mouthpiece tube 1.

[0047] Referring to FIG. 5 and FIG. 6, in some embodiments, the current collector 2 can be made of plastic. For example, the current collector 2 and the nano-injection part 3 can be integrally formed by nano-injection molding. The current collector 2 covers part of the first connecting end 11 to form the second connecting end 21. Specifically, when the current collector 2 needs to be connected to the reed pipe 1, the surface of the first connecting end 11 of the reed pipe 1 can be treated to form a plurality of nano-pores. Then the reed pipe 1 is placed in a prefabricated injection mold. The reed pipe 1 occupies part of the cavity of the injection mold, while the part of the cavity of the injection mold corresponding to the current collector 2 and the nano-injection part 3 is not occupied. When nano-injection molding is performed, the plastic fluid will fill the part of the cavity corresponding to the current collector 2 and the nano-injection part 3, and after the plastic fluid cools, an integrated plastic current collector and nano-injection part 3 are formed. The nano-injection part 3 and the second connecting end 21 of the current collector 2 are fixedly attached to the first connecting end 11 of the reed pipe 1, and the nano-injection part 3 fills the nano-pores on the first connecting end 11 to achieve a sealed and fixed connection between the current collector 2 and the reed pipe 1.

[0048] Referring to FIG. 7 and FIG. 8, in some embodiments, the current collector 2 can be a combined current collector having a metal part 24 and a plastic part 25. The plastic part 25 is adjacent to one end of the reed pipe 1 to form the second connecting end 21, and the plastic part 25 can be integrally formed with the nano-injection part 3. The metal part 24 is connected to the plastic part 25. The metal part 24 can be made of aluminum alloy. The metal part 24 can include the first connecting part 23 and form a connecting port 231 that is in communication with the outside. To improve the bonding force between the metal part 24 and the plastic part 25, the surface of the end of the metal part 24 connected to the plastic part 25 can form a plurality of nano-pores. The plastic part 25 can be formed by nano-injection molding, and the plastic part 25 can fill the nano-pores formed on the metal part 24. The metal part 24 and the plastic part 25 together form the current collector 2. The connection position of the metal part 24 and the plastic part 25 can be selected at different positions of the current collector 2 as needed. Specifically, the connection position of the metal part 24 and the plastic part 25 is at the position where the step structure is formed in the current collector 2. For example, the connection position of the second connecting part 22 and the first connecting part 23 in the current collector 2 forms a step structure. The second connecting part 22 forms the plastic part 25, and the first connecting part 23 forms the metal part 24. Alternatively, the connection position of the metal part 24 and the plastic part 25 can be formed on the second connecting part 22. Part of the second connecting part 22 forms the metal part 24 with the first connecting part 23, and another part of the second connecting part 22 forms the plastic part 25. Alternatively, the connection position of the metal part 24 and the plastic part 25 can be formed on the first connecting part 23. Part of the first connecting part 23 forms the plastic part 25 with the first connecting part 23, and another part of the first connecting part 23 forms the metal part 24.

[0049] When it is needed to connect the current collector 2 with the mouthpiece tube 1, the metal part 24 and the mouthpiece tube 1 can be surface treated first, so that the metal part 24 forms nano micro-holes at the end for connecting with the plastic part 25, and the first connecting end 11 of the mouthpiece tube 1 forms nano micro-holes. The metal part 24 and the mouthpiece tube 1 are placed into a prefabricated injection mold, the mouthpiece tube 1 and the metal part 24 occupy part of the cavity in the injection mold, and the part of the cavity in the injection mold corresponding to the plastic part 25 and the nano injection part 3 is not occupied. When nano injection is performed, the plastic fluid will fill the part of the cavity corresponding to the plastic part 25 and the nano injection part 3, and after the plastic fluid cools, the plastic part 25 and the nano injection part 3 are formed in one piece. The plastic part 25 is fixedly attached to the metal part 24 and fills the nano micro-holes on the metal part 24 to achieve sealed and fixed connection of the plastic part 25 with the metal part 24; the nano injection part 3 is fixedly attached to the first connecting end 11 and fills the nano micro-holes on the first connecting end 11 to achieve sealed and fixed connection of the plastic part 25 integrally connected with the nano injection part 3 with the mouthpiece tube 1.

[0050] In some possible ways, when the opposite two ends of the mouthpiece tube 1 are both provided with the first connecting end 11, the mouthpiece tube 1 is connected with a pair of current collectors 2, which can be the same type of current collector 2, for example, a pair of current collectors 2 are both metal current collectors, plastic current collectors, or combined current collectors; or, the pair of current collectors 2 can be different types of current collectors 2, for example, one current collector 2 is a metal current collector, and the other current collector 2 is a plastic current collector; or, one current collector 2 is a metal current collector, and the other current collector 2 is a combined current collector; or, one current collector 2 is a combined current collector, and the other current collector 2 is a plastic current collector.

Claims

1. A liquid cooling plate assembly, wherein: include: A harmonica tube (1) comprises a first connecting end (11), wherein at least a portion of the surface of the first connecting end (11) is formed with a plurality of nano-micropores; A current collector (2) comprising a second connection end (21), wherein the second connection end (21) is connected to the first connection end (11); A nano-injection molding part (3) is provided at the connection between the first connection end (11) and the second connection end (21); the nano-injection molding part (3) fixedly covers the first connection end (11) and the second connection end (21); and the nano-injection molding part (3) fills the nano-micropores formed by the first connection end (11).

2. The liquid cooling plate assembly according to claim 1, wherein: The current collector (2) is a metal current collector, a plurality of nanopores are formed on at least a portion of the surface of the second connection end (21), and the nano-injection molding part (3) fills the nanopores formed by the second connection end (21).

3. The liquid cooling plate assembly according to claim 2, wherein: The second connecting end (21) is provided with at least a portion of a liquid supply chamber (221), a portion of the first connecting end (11) extends into the liquid supply chamber (221), and the portion of the first connecting end (11) exposed from the liquid supply chamber (221) is formed with the nanopore.

4. The liquid cooling plate assembly according to claim 2, wherein: The current collector (2) comprises a second connecting portion (22) and a first connecting portion (23) fixedly connected to the second connecting portion (22), the second connecting portion (22) forming the second connecting end (21), and the first connecting portion (23) is provided with a connecting port (231) communicating with the outside.

5. The liquid cooling plate assembly according to claim 1, wherein: The current collector (2) further comprises a metal portion (24) and a plastic portion (25) connected to each other, wherein the plastic portion (25) is adjacent to one end of the harmonica tube (1) to form the second connection end (21), and the plastic portion (25) forms an integrated structure with the nano-injection molding portion (3).

6. The liquid cooling plate assembly according to claim 5, wherein: A plurality of nano-micropores are formed at one end of the metal part (24) connected to the plastic part (25); the plastic part (25) fills the nano-micropores formed by the metal part (24) and is fixedly connected to the metal part (24).

7. The liquid cooling plate assembly according to claim 5, wherein: The metal part (24) includes a first connecting part (23), and the first connecting part (23) is provided with a connecting port (231) communicating with the outside.

8. The liquid cooling plate assembly according to claim 1, wherein: The current collector (2) is a plastic current collector, and the portion of the current collector (2) covering the first connection end (11) forms the second connection end (21); the nano-injection molding portion (3) and the current collector (2) form an integrated structure.

9. The liquid cooling plate assembly according to claim 1, wherein: The opposite ends of the harmonica tube (1) are respectively provided with first connecting ends (11), a pair of current collectors (2) are provided, a pair of the current collectors (2) are connected to a pair of the first connecting ends (11) in a one-to-one correspondence, and at least one of the current collectors (2) is connected to at least one of the first connecting ends (11) via the nano-injection molding part (3).

10. The liquid cooling plate assembly according to claim 9, wherein: The pair of current collectors (2) are of the same or different types, and the type of the current collector (2) is one of a metal current collector, a plastic current collector, or a combined current collector having a metal portion (24) and a plastic portion (25).

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