Side liquid inlet galvanic pile structure and welding device thereof

Abstract

The invention relates to the technical field of flow batteries, in particular to a side liquid inlet galvanic pile structure and a welding device thereof, a flow frame in a galvanic pile comprises a plate body, and a rectangular through hole is formed in the plate body; an electrolyte runner is arranged on each of the upper side and the lower side of the rectangular through hole in the plate surface on one side of the plate body; the electrolyte runners are used for communicating the rectangular through hole with the side edge of the plate body; a group of through grooves are formed in the side edge of the plate body and located on the upper side and the lower side of the electrolyte flow channel, and a group of through grooves are also formed in the opposite positions of the side edge, opposite to the side edge provided with the through grooves, of the plate body; u-shaped grooves are formed in the positions, opposite to the through grooves, of the side edges of the end plates. After the whole stack is packaged, the U-shaped grooves of the end plates on the two sides and the groups of through grooves corresponding in position jointly form a mounting groove with a concentric-square-shaped structure, and the mounting groove is used for mounting a connector; the electrolyte can independently enter and exit from each single battery piece, and the average charging and discharging efficiency of the flow battery is improved; and the electrolyte circulation of other single battery pieces is not influenced by the blockage of the electrolyte flow channel in one single battery piece.

Description

Technical Field

[0001] The invention relates to the technical field of liquid flow batteries, in particular to a side-inlet liquid battery stack structure and a welding device thereof. Background Art

[0002] Liquid flow battery is a battery system that realizes the mutual conversion of electrical energy and chemical energy through the redox reaction of active substances. It has the characteristics of high capacity, wide application field and long cycle life. It is a new energy product at present. Liquid flow battery has broad market prospects in the fields of wind power, solar power and other new energy power generation, smart grid construction, electric vehicle charging stations, power supply in remote areas, etc. The liquid flow battery system includes positive electrolyte storage tank, negative electrolyte storage tank, battery stack unit, electrolyte circulation pipeline, circulation pump, control module and other components.

[0003] In the prior art, such as a flow battery stack structure of application number CN202111489661.1, each stack includes two left and right end plates, and a plurality of single cells are arranged between the two end plates from left to right through the bipolar plate, and each single cell includes a positive electrode located in a through hole in the middle of a positive electrode frame, an ion conductive membrane, and a negative electrode located in a through hole in the middle of a negative electrode frame, which are stacked from left to right; N is respectively opened at the corresponding positions on the left end plate and the bipolar plate. Through holes as the inlet of positive electrode electrolyte, N through holes as the outlet of positive electrode electrolyte, N through holes as the inlet of negative electrode electrolyte, and N through holes as the outlet of negative electrode electrolyte are connected in series to form channels, so that the positive and negative electrode electrolytes enter and exit each single cell through each channel; in the prior art, a main pipeline and a main valve are used to supply liquid to the battery stack, and the electrode liquid is distributed to the electrolyte flow channel of the liquid flow frame of each single cell through the channel to provide electrode liquid for each single cell.

[0004] When using the battery stack structure in the prior art, the electrolyte flow rate and flow velocity of the liquid flow frame where the through holes are located close to the positive electrode liquid pipeline or the negative electrode liquid pipeline are different from those of the liquid flow frame where the through holes are located far away from the positive electrode liquid pipeline or the negative electrode liquid pipeline. The electrolyte pressures applied to each single cell in the battery stack are different, which will lead to uneven electrolyte flow rates of each single cell in the battery stack, thereby reducing the overall power supply and charging efficiency of the liquid flow battery. At the same time, since there will be more or less impurities in the electrode liquid, the through holes in series are prone to blockage during use. Once blockage occurs, the overall electrolyte circulation of the battery stack will be interrupted, affecting the use of the battery stack, and sometimes causing irreparable serious losses to customers. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a side-inlet battery stack structure and a welding device thereof that enable each single cell to independently enter and exit the electrolyte, thereby avoiding the problem of uneven electrolyte flow in each single cell in the battery stack.

[0006] The technical solution adopted by the present invention to solve its technical problem is: A side-inlet liquid battery stack structure includes two left and right end plates, and a plurality of single cells are arranged between the two end plates from left to right through bipolar plates. Each single cell includes a positive electrode, a liquid flow frame for mounting the positive electrode, an ion conductive membrane, a negative electrode, and a liquid flow frame for mounting the negative electrode, which are stacked from left to right. The liquid flow frame includes a plate body, and a rectangular through hole for accommodating the positive electrode or the negative electrode is provided in the middle of the plate body. An electrolyte flow channel is provided on the upper and lower sides of the rectangular through hole on the plate surface on one side of the plate body. The electrolyte flow channel is used to connect the rectangular through hole and the side of the plate body; a group of through grooves are opened on the upper and lower sides of the electrolyte flow channel on the side of the plate body, and a group of through grooves are also opened at the relative position of the opposite side of the plate body with the through groove side; U-shaped grooves are arranged on the side of the end plate relative to each group of through grooves; after the battery stack is packaged as a whole, the U-shaped grooves of the end plates on both sides and the corresponding groups of through grooves together constitute a mounting groove of a U-shaped structure, and the mounting groove is used to install a connector, and the connector cooperates with the electrolyte flow channel to realize the electrolyte circulation of each single battery.

[0007] Compared with the prior art, the present invention adopting the above technical solution has the following outstanding features: The present invention realizes side liquid inlet by designing an electrolyte flow channel to be connected with the side edge of a liquid flow frame plate body, and by arranging a through groove on the plate body and a U-shaped groove on the end plate, after the battery stack is packaged as a whole, a mounting groove with a U-shaped structure is formed on the outside of the electrolyte flow channel, which is convenient for installing a connector. The connector is used to connect an electrolyte circulation pipeline to realize the distribution of electrolyte to each single cell and the reflux of electrolyte in each single cell; the electrolyte can be independently in and out of each single cell sheet, so as to avoid uneven electrolyte flow of each single cell sheet in the battery stack, and improve the average charge and discharge efficiency of the liquid flow battery; at the same time, the blockage of the electrolyte flow channel in one single cell sheet does not affect the electrolyte circulation of other single cell sheets and does not affect the use of the battery stack.

[0008] Preferably, a further technical solution of the present invention is: Preferably, the connector comprises a bottomless shell, and a liquid guide hole for connecting an electrolyte circulation pipeline is provided on the top plate of the shell.

[0009] Preferably, a supporting transverse rib is provided in the middle of the shell, the upper edge of the supporting transverse rib is connected to the top plate of the shell, the left end is connected to the left side wall of the shell, the right end is connected to the right side wall of the shell, and the distance between the lower edge and the bottom of the shell is not less than the depth of the through groove on the plate body; two liquid guide holes are provided, respectively located on both sides of the supporting transverse rib.

[0010] Preferably, the electrolyte flow channel includes a liquid collecting portion connected to the side of the plate body, and a flow guiding portion connected to the liquid collecting portion and the rectangular through hole.

[0011] Preferably, the width of the liquid collecting portion is greater than that of the flow guiding portion.

[0012] Preferably, a guide bar is provided in the liquid collecting portion, and the guide bar is a parallelepiped structure.

[0013] Preferably, the guide strip is arranged centered on the liquid collecting portion in the width direction.

[0014] A welding device for a side-inlet liquid-filled battery stack structure comprises a hot-melt welding machine, on which a heat-conducting plate is provided, and a first die head adapted to a mounting groove and a second die head adapted to a connector are detachably connected on both sides of the heat-conducting plate; the first die head can be used to heat the mounting groove, and the second die head can be used to heat the connector, so that the connector can be hot-melt welded to the mounting groove on the side of the battery stack; welding is simpler and more convenient.

[0015] Preferably, the first die head comprises a plug in the shape of a rectangular cylinder, and supporting longitudinal ribs are arranged in the plug cylinder.

[0016] Preferably, the second die head is a sleeve having a return groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a side-inlet liquid stack structure in an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of the liquid flow frame in an embodiment of the present invention; Figure 3 is a schematic diagram of the structure of the end plate in an embodiment of the present invention; Figure 4 is a schematic structural diagram of a connector in an embodiment of the present invention; Figure 5 It is a schematic diagram of the structure of the first die head in an embodiment of the present invention; Figure 6 It is a schematic diagram of the second die head in an embodiment of the present invention.

[0018] Explanation of the reference numerals: 1. end plate; 101. U-shaped groove; 2. liquid flow frame; 201. rectangular through hole; 202. electrolyte flow channel; 203. through groove; 3. guide bar; 4. mounting groove; 5. shell; 501. liquid guide hole; 6. supporting transverse rib; 7. plug; 8. supporting longitudinal rib; 9. sleeve. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with specific embodiments, the purpose of which is only to provide a better understanding of the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0020] The present embodiment provides a side-inlet liquid battery stack structure, including two left and right end plates 1, and a plurality of single cells are arranged between the two end plates 1 from left to right through the bipolar plate interval, and each single cell includes a positive electrode, a liquid flow frame 2 for mounting the positive electrode, an ion conductive membrane, a negative electrode, and a liquid flow frame 2 for mounting the negative electrode, which are stacked from left to right; the liquid flow frame 2 includes a plate body, and a rectangular through hole 201 for accommodating the positive electrode or the negative electrode is provided in the middle of the plate body; an electrolyte flow channel 202 connected to the rectangular through hole 201 is provided on the upper and lower sides of the rectangular through hole 201 on the plate surface on one side of the plate body, and the electrolyte flow channel 202 is in a long strip shape, and one end of the electrolyte flow channel 202 is connected to the side of the plate body; Figure 2 A group of through grooves 203 are provided on the side of the plate body at the upper and lower sides of the electrolyte flow channel 202, and a group of through grooves 203 are also provided at the opposite side of the plate body where the through grooves 203 are provided; that is, four through grooves 203 are provided on each liquid flow frame 2, two in a group, and the two groups of through grooves 203 are respectively located on the opposite side sides; Figure 3 Correspondingly, a U-shaped groove 101 is provided at a position opposite to each group of through grooves 203 on the side of the end plate 1; Figure 1 After the battery stack is packaged as a whole, the U-shaped grooves 101 of the end plates 1 on both sides and the corresponding through grooves 203 together form a mounting groove 4 of a U-shaped structure, and the mounting groove 4 is used to install Figure 4 The connector shown cooperates with the electrolyte flow channel 202 to realize the electrolyte circulation of each single cell.

[0021] As an implementation method, Figure 2 The two electrolyte flow channels 202 may be connected to the same side of the plate body, that is, when the electrolyte flows into and out of the liquid flow frame 2, it flows in and out on the same side; as another embodiment, the two electrolyte flow channels 202 may be respectively connected to the two opposite sides of the plate body, that is, when the electrolyte flows into and out of the liquid flow frame 2, it flows in on one side of the liquid flow frame 2 and flows out on the other side.

[0022] In general, the electrolyte flow channel 202 is designed to be connected to the side of the liquid flow frame 2 plate to achieve side liquid inlet, and by providing a through groove 203 on the plate body and a U-shaped groove 101 on the end plate 1, after the battery stack is packaged as a whole, a mounting groove 4 with a U-shaped structure is formed on the outside of the electrolyte flow channel 202 to facilitate the installation of a connector, and the connector is used to connect the electrolyte circulation pipeline to achieve the distribution of electrolyte to each single cell and the reflux of electrolyte in each single cell; to achieve independent entry and exit of electrolyte for each single cell sheet, to avoid uneven electrolyte flow of each single cell sheet in the battery stack, and to improve the average charging and discharging efficiency of the liquid flow battery; at the same time, the blockage of the electrolyte flow channel 202 in a single cell sheet does not affect the electrolyte circulation of other single cell sheets, and does not affect the use of the battery stack.

[0023] The specific structure of the connector is as follows Figure 4 As shown, it includes a bottomless shell 5 adapted to the mounting groove 4 of the Chinese-shaped structure, and a liquid guide hole 501 for connecting the electrolyte circulation pipeline is provided on the top plate of the shell 5. The electrolyte circulation pipeline flows the electrolyte into or out of the connector from the liquid guide hole 501; taking the inflow of positive electrode electrolyte as an example, the positive electrode electrolyte flows into the connector from the positive electrode electrolyte circulation pipeline, and then enters the electrolyte flow channel 202 through the electrolyte flow channel 202 entrance on the side of the liquid flow frame 2, flows to the rectangular through hole 201 through the electrolyte flow channel 202, and is transported to the positive electrode; taking the output of positive electrode electrolyte as an example, the positive electrode electrolyte flows from the positive electrode to the electrolyte flow channel 202, flows out from the side of the liquid flow frame 2, is collected in the mounting groove 4, and is sent to the positive electrode electrolyte circulation pipeline by the connector for circulation; the same is true for the negative electrode electrolyte.

[0024] In order to prevent the top plate of the connector from completely resting on the electrolyte flow channel 202 during hot melt welding and the electrolyte from entering the electrolyte flow channel 202, a supporting transverse rib 6 is provided in the middle of the shell 5, and the upper edge of the supporting transverse rib 6 is connected to the top plate of the shell 5, the left end is connected to the left side wall of the shell 5, the right end is connected to the right side wall of the shell 5, and the distance between the lower edge and the bottom of the shell 5 is not less than the depth of the through groove 203 on the plate body; the supporting transverse rib 6 can, on the one hand, prevent the connector from deforming after heating; on the other hand, it can serve as a limiter to prevent the pressure from being too long or too high when hot-melt welding the connector and the battery stack, thereby damaging the electrolyte flow channel 202 and affecting the electrolyte transportation.

[0025] like Figure 2 The electrolyte flow channel 202 includes a liquid collecting portion connected to the side of the plate body, and a guide portion connecting the liquid collecting portion and the rectangular through hole 201; the width of the liquid collecting portion is greater than the guide portion; a guide bar 3 is also arranged in the liquid collecting portion, and the guide bar 3 is a parallelepiped structure, and the guide bar 3 is arranged in the center of the liquid collecting portion in the width direction; the electrolyte flow channel 202 is an overall Y-shaped structure, which can increase the flow rate of the electrolyte, strengthen the mass transfer inside the battery stack unit, and improve the reaction rate.

[0026] A welding device for a side-inlet liquid battery stack structure includes a hot melt welding machine, on which a heat conducting plate is provided, and a first die head adapted to a mounting groove 4 and a second die head adapted to a connector are detachably connected on both sides of the heat conducting plate; the first die head includes a plug 7 in the shape of a rectangular cylinder, and a supporting longitudinal rib 8 is provided in the plug cylinder, and the supporting longitudinal rib 8 serves to prevent the plug cylinder from being heated and deformed; the second die head is a sleeve 9 with a return groove.

[0027] When in use, the first die head and the second die head are heated by the heat conduction plate, the U-shaped mounting groove 4 in the battery stack body is heated by the first die head, the connector is inserted into the second die head, the outer surface, inner surface and bottom surface of the four sides of the connector are heated by the second die head, and then the connector is placed in the mounting groove 4, a pressure of 80-120 kg is applied for 3-5 seconds, and then the welding is completed after cooling; welding is simpler and more convenient.

[0028] The above description is only the preferred embodiment of the present invention, and does not limit the scope of rights of the present invention. All equivalent changes made by using the contents of the present invention specification and its drawings are included in the scope of rights of the present invention.

Claims

1. A side-inlet liquid battery stack structure, comprising two left and right end plates (1), a plurality of single cells being arranged in sequence from left to right through bipolar plates between the two end plates (1), each single cell comprising a positive electrode, a liquid flow frame (2) for mounting the positive electrode, an ion conductive membrane, a negative electrode, and a liquid flow frame (2) for mounting the negative electrode, which are stacked in sequence from left to right; the liquid flow frame (2) comprising a plate body, a rectangular through hole (201) for accommodating the positive electrode or the negative electrode being provided in the middle of the plate body; Features: An electrolyte flow channel (202) is provided on the plate surface on one side of the plate body, on both upper and lower sides of the rectangular through hole (201), respectively, and the electrolyte flow channel (202) is used to connect the rectangular through hole (201) and the side of the plate body; A group of through grooves (203) are provided on the side of the plate body at the upper and lower sides of the electrolyte flow channel (202), and a group of through grooves (203) are also provided at the opposite position of the side of the plate body opposite to the side of the through groove (203); A U-shaped groove (101) is provided on the side of the end plate (1) at a position opposite to each group of through grooves (203); After the battery stack is packaged as a whole, the U-shaped grooves (101) of the end plates (1) on both sides and the corresponding groups of through grooves (203) together form a mounting groove (4) of a U-shaped structure, and the mounting groove (4) is used to install a connector, and the connector cooperates with the electrolyte flow channel (202) to realize the circulation of electrolyte in each single battery.

2. The side-inlet liquid stack structure according to claim 1 is characterized in that: The connector comprises a bottomless shell (5), and a liquid guide hole (501) for connecting an electrolyte circulation pipeline is provided on the top plate of the shell (5).

3. The side-inlet liquid stack structure according to claim 2 is characterized in that: A supporting transverse rib (6) is provided in the middle of the shell (5); the upper edge of the supporting transverse rib (6) is connected to the top plate of the shell (5); the left end is connected to the left side wall of the shell (5); the right end is connected to the right side wall of the shell (5); the distance between the lower edge and the bottom of the shell (5) is not less than the depth of the through groove (203) on the plate body; two liquid guide holes (501) are provided, respectively located on both sides of the supporting transverse rib (6).

4. The side-inlet liquid stack structure according to claim 1, characterized in that: The electrolyte flow channel (202) comprises a liquid collecting portion connected to the side of the plate body, and a flow guiding portion connected to the liquid collecting portion and the rectangular through hole (201).

5. The side-inlet liquid stack structure according to claim 4 is characterized in that: The width of the liquid collecting portion is greater than that of the flow guiding portion.

6. The side-inlet liquid stack structure according to claim 5, characterized in that: A guide bar (3) is arranged in the liquid collecting portion, and the guide bar (3) is a parallelepiped structure.

7. The side-inlet liquid stack structure according to claim 6, characterized in that: The guide strip (3) is arranged in the center of the liquid collecting portion in the width direction.

8. A welding device for a side-inlet liquid stack structure, comprising a hot melt welding machine, on which a heat conducting plate is provided, characterized in that: A first die head adapted to the mounting groove (4) and a second die head adapted to the connector are detachably connected to both sides of the heat conducting plate.

9. The welding device for the side-inlet liquid stack structure according to claim 8 is characterized in that: The first die head comprises a plug (7) in the shape of a rectangular cylinder, and a supporting longitudinal rib (8) is arranged in the plug cylinder.

10. The welding device for side-inlet liquid stack structure according to claim 8, characterized in that: The second die head is a sleeve (9) having a return groove.

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