Sealing assembly process of flow battery stack

Abstract

The invention relates to the technical field of flow battery stacks, and discloses a flow battery stack which comprises a plurality of unit modules, and each unit module comprises a bipolar plate, a guide plate A, a guide plate B, an electrode A, an electrode B and an ionic membrane; wherein the front surface of the bipolar plate is connected with the back surface of the flow guide plate A through laser welding, the back surface of the bipolar plate is connected with the back surface of the flow guide plate B through laser welding, central cutting areas of the flow guide plate A and the flow guide plate B are reaction areas and are used for placing an electrode A and an electrode B, and a central shadow area of the front surface of the flow guide plate A is a welding area of an ionic membrane; the electrode A is positioned in the reaction region on the front surface of the guide plate A; the guide plate A, the guide plate B and the bipolar plate are integrally welded through a laser welding technology, and the traditional sealant is replaced, so that the sealing property of the battery stack is greatly improved, the liquid leakage problem is avoided, and the sealing stability of the battery in long-term use is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery stacks, and in particular to a sealing assembly process for a liquid flow battery stack. Background Art

[0002] The power unit of a flow battery stack is composed of a certain number and specifications of battery cells connected in series. The stack is the place where electrochemical reactions occur. Its main structure includes ion exchange membranes, electrodes, bipolar plates, copper current collecting plates, liquid flow frames and end plates, among which ion exchange membranes, electrodes and bipolar plates are core components.

[0003] Patent CN202410120708.4 proposes a flow battery stack assembly process and method, which uses laser melting welding ribs (height 0.1-2mm), which can easily cause glue overflow and uneven weld marks, resulting in differences in single-stage batteries and a risk of leakage during press assembly; the bipolar plate is conductive as a whole, and the positive / negative electrode inlet and outlet holes form a loop, which reduces the system efficiency; the single-stage batteries are sealed with a special sealant, which takes 8-24 hours to cure and has low assembly efficiency.

[0004] Patent CN201110136369.1 proposes a sealing method for a flow battery stack and an integrated stack. The layout of the hot melt lines is too compact, and the hot melt lines overlap at key positions, resulting in the accumulation of hot melt lines and a large gap in the stack press. The frame plate and the guide plate are divided into two parts, which complicates the assembly of parts and processes.

[0005] The working principle of flow batteries determines that they must have good sealing performance. At present, the sealing structure between the components of the battery stack mainly uses sealing gaskets or sealing strips for compression sealing. As the battery stack runs for a long time, the rubber sealing material will gradually age and lose its sealing effect.

[0006] To this end, those skilled in the art provide a sealing assembly process for a flow battery stack to solve the problems raised in the above background technology. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a sealing assembly process for a liquid flow battery stack, which solves the problem that the rubber sealing material of the existing liquid flow battery stack will gradually age and lose its sealing effect after long-term operation.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a liquid flow battery stack, including a plurality of unit modules, wherein the unit modules include a bipolar plate, a guide plate A, a guide plate B, an electrode A, an electrode B and an ion membrane;

[0009] Among them, the front side of the bipolar plate is connected to the back side of the guide plate A by laser welding, and the back side of the bipolar plate is connected to the back side of the guide plate B by laser welding. The central cut-out area of ​​the guide plate A and the guide plate B is the reaction area for placing the electrode A and the electrode B. The central shadow area on the front side of the guide plate A is the welding area of ​​the ion membrane.

[0010] Preferably, the electrode A is located in the reaction zone on the front side of the guide plate A, and the ion membrane is welded to the shadow area at the center of the front side of the guide plate A by laser technology.

[0011] Preferably, the electrode B is located in the second reaction zone between the reverse side of the guide plate B and the reverse side of the bipolar plate, so that the electrode A, the guide plate A, the bipolar plate, the guide plate B and the electrode B together constitute a unit module.

[0012] Preferably, a plurality of the unit modules are stacked to form a battery stack, and the unit modules are sealed by a sealing film to form a complete battery stack.

[0013] Preferably, the liquid inlet and the liquid outlet of the guide plate A and the guide plate B are respectively aligned with the inlet channel hole and the outlet channel hole provided on the bipolar plate, and are fixed by laser welding to form an integral structure.

[0014] Preferably, the bipolar plate is divided into a reaction zone and an insulating zone, the reaction zone is in contact with electrode A and electrode B, the insulating zone is welded to guide plate A and guide plate B, and symmetrical outlet holes and inlet holes are arranged along the length direction of the bipolar plate.

[0015] Preferably, the guide plate A and the guide plate B are made of PP / PE, with a light transmittance of 30%-80% and a thickness of 2.5-5 mm.

[0016] Preferably, the sealing film is made of PP / PE with a thickness of 0.1-1 mm and is used for sealing between unit modules.

[0017] Preferably, the ion membrane is a perfluorosulfonic acid ion membrane or a porous membrane, which is welded to the front center shadow area of ​​the guide plate A.

[0018] A sealing assembly process for a flow battery stack, used for a flow battery stack, comprises the following steps:

[0019] S1: placing the back side of the guide plate A on the front side of the bipolar plate, and aligning the liquid inlet and the liquid outlet of the guide plate A with the inlet channel hole and the outlet channel hole of the bipolar plate respectively, and fixing the guide plate A and the bipolar plate by laser welding;

[0020] S2: placing the reverse side of the guide plate B on the reverse side of the bipolar plate, and aligning the liquid inlet and the liquid outlet of the guide plate B with the inlet channel hole and the outlet channel hole of the bipolar plate respectively, and fixing the guide plate B and the bipolar plate by laser welding; at this time, the guide plate A, the bipolar plate and the guide plate B form an integral component;

[0021] S3: placing electrode A in the first reaction zone between the back side of guide plate A and the front side of bipolar plate, placing ion membrane in the central shadow area of ​​the front side of guide plate A, and welding the ion membrane to the shadow area by laser welding;

[0022] S4: placing the guide plate B of the integral component formed in S2 with the front side facing upward, and placing the electrode B in the second reaction zone between the reverse side of the guide plate B and the reverse side of the bipolar plate; at this time, the bipolar plate, the guide plate A, the guide plate B, the electrode A, the electrode B and the ion membrane form a complete unit module;

[0023] S5: Place a sealing membrane on the front side of the guide plate B, avoiding the sealing area of ​​the ion membrane; symmetrically set two groups of sealing holes along the length direction of the sealing membrane, the sealing holes correspond to the liquid inlet and outlet set on the guide plate B, and are aligned; stack and place multiple unit modules as needed, and finally form a complete battery stack by pressing.

[0024] The present invention provides a sealing assembly process for a flow battery stack, which has the following beneficial effects:

[0025] 1. The present invention uses laser welding technology to weld the guide plate A, the guide plate B and the bipolar plate as a whole, replacing the traditional sealant, greatly improving the sealing of the battery stack, avoiding the occurrence of leakage problems, and ensuring the sealing stability of the battery during long-term use.

[0026] 2. The present invention adopts a modular design, and the unit modules can be flexibly stacked according to the power requirements of the battery stack. The assembly process is simplified, and the production efficiency is significantly improved. At the same time, the curing waiting time of the sealant is eliminated, the production cycle is shortened, and the convenience of production and maintenance is further improved.

[0027] 3. The bipolar plate of the present invention is designed with materials that are insulated all around and have a highly conductive central reaction zone, which avoids the problem of loops formed between the positive and negative electrode liquid inlet and outlet holes, significantly improves the conductivity and overall efficiency of the system, and reduces the risk of energy loss and stack performance degradation.

[0028] 4. The present invention uses PP / PE material as the guide plate and sealing film. The material has good light transmittance, heat resistance and mechanical strength, can adapt to various working environments, prolongs the service life of the battery stack, and ensures the stability and reliability of the battery in harsh environments.

[0029] 5. The bipolar plate of the present invention is insulated on all sides and has a highly conductive material in the central reaction area to avoid the formation of a loop between the positive / negative electrode inlet and outlet holes, which reduces the system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the exploded structure of the unit module of the present invention;

[0031] Figure 2 This is a schematic diagram of the front structure of the guide plate A of the present invention;

[0032] Figure 3 This is a schematic diagram of the reverse structure of the guide plate A of the present invention;

[0033] Figure 4 This is a schematic diagram of the front structure of the bipolar plate of the present invention;

[0034] Figure 5 This is a schematic diagram of the stacking structure of the present invention;

[0035] Figure 6 It is a schematic diagram of the process steps of the present invention.

[0036] Among them, 1. unit module; 2. electrode A; 3. electrode B; 4. ion membrane; 5. sealing membrane; 10. guide plate A; 11. guide plate B; 20. bipolar plate; 101. center shadow; 102. sealing area; 103. liquid outlet; 104. liquid inlet; 201. reaction area; 202. insulation area; 203. outlet channel hole; 204. inlet channel hole. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings 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 of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] Reference Figure 1-Figure 4 As shown, the present invention provides a flow battery stack unit, including an electrode A2, an electrode B3, an ion membrane 4, a guide plate A10, a guide plate B11, and a bipolar plate 20. The specific steps are as follows:

[0040] S1, firstly, the reverse side of the guide plate A10 and the front side of the bipolar plate 20 are laser welded, and then the reverse side of the guide plate B11 and the reverse side of the bipolar plate 20 are laser welded, and the three are formed into a whole. By aligning the liquid inlet 104 and the liquid outlet 103 of the guide plate A10 and the bipolar plate 20 with the flow channel holes 203, 204, and using laser welding, the sealing and tight connection of the overall structure are ensured.

[0041] S2, then put the electrode A2 into the reaction tank on the front side of the guide plate A10, and then weld the ion membrane 4 to the central shadow area 101 on the front side of the guide plate A10 by laser technology to ensure the sealing of the area and the stability of the electrochemical reaction.

[0042] S3, place the guide plate B11 of the integral component in S2 with the front side facing upward, and place the electrode B3 in the second reaction tank between the back side of the guide plate B11 and the back side of the bipolar plate 20, so that the above 6 components form a unit module 1. According to the required assembled stack power, the appropriate number of unit modules 1 are assembled and stacked. Through this structure, the power output of the stack can be flexibly adjusted according to actual needs.

[0043] S4, finally, the unit modules 1 are sealed with a sealing film 5 to form a complete battery stack. The sealing film 5 is symmetrically provided with two sets of sealing holes along the length direction, which are aligned with the liquid inlet 104 and the liquid outlet 103 provided on the guide plate B11, thereby ensuring the sealing of the battery stack and the stability of fluid conduction.

[0044] In the guide plate A10 and the guide plate B11, the guide plate A10 is divided into a front side and a back side, and the guide plate B11 is also divided into a front side and a back side. The central cut-out area of ​​the guide plate A10 and the guide plate B11 is the reaction area 201 for placing electrodes, and the central shadow area 101 of the front side of the guide plate A10 is the welding area of ​​the ion membrane 4.

[0045] The bipolar plate 20 is divided into a front side and a back side, and the bipolar plate 20 is provided with two regions, a reaction region 201 and an insulating region 202. The reaction region 201 is in contact with the electrode, and the insulating region 202 is welded to the guide plate A10 and the guide plate B11. The insulating region 202 is symmetrically provided with two groups of flow channel holes 203 and 204 along the length direction of the bipolar plate 20, and the guide plate A10 and the guide plate B11 are both provided with a liquid inlet 104 and a liquid outlet 103 corresponding to the two groups of flow channel holes.

[0046] In step S1, the reverse side of the guide plate A10 and the front side of the bipolar plate 20 are laser welded to form a first reaction tank for placing the electrode A2, and then the reverse side of the guide plate B11 and the reverse side of the bipolar plate 20 are laser welded to form a second reaction tank for placing the electrode B3. Through these steps, a double reaction zone is formed, so that the battery stack has higher sealing performance and electrochemical reaction efficiency.

[0047] The guide plate is made of PP / PE with a transmittance of 30%-80% and a thickness of 2.5-5mm; the sealing film 5 is made of PP / PE with a thickness of 0.1-1mm; the bipolar plate 20 is made of a material with insulation all around and high conductivity in the central reaction area to ensure the overall efficiency and durability of the battery stack.

[0048] Embodiment 2:

[0049] Reference Figure 5-Figure 6 As shown, the embodiment of the present invention provides a sealing assembly process for a flow battery stack unit according to the above-mentioned unit module 1, and the steps are as follows:

[0050] The reverse side of the guide plate A10 is placed on the front side of the bipolar plate 20, and the liquid inlet 104 and the liquid outlet 103 of the guide plate A10 are respectively aligned with the flow channel holes 203 and 204 of the bipolar plate 20, and the guide plate A10 and the bipolar plate 20 are fixed by laser welding;

[0051] The reverse side of the guide plate B11 is placed on the reverse side of the bipolar plate 20, and the liquid inlet 104 and the liquid outlet 103 of the guide plate B11 are respectively aligned with the flow channel holes 203 and 204 of the bipolar plate 20, and the guide plate B11 and the bipolar plate 20 are fixed by laser welding, so that the guide plate A10, the bipolar plate 20 and the guide plate B11 form an integral component;

[0052] The electrode A2 is placed in the first reaction tank between the back side of the guide plate A10 and the front side of the bipolar plate 20, the ion membrane 4 is placed in the central shadow area 101 on the front side of the guide plate A10, and the ion membrane 4 is welded to the central shadow area 101 by laser welding;

[0053] Place the guide plate B11 of the integral component in S2 with the front side facing upward, and place the electrode B3 in the second reaction tank between the reverse side of the guide plate B11 and the reverse side of the bipolar plate 20. The bipolar plate 20, the guide plate A10, the guide plate B11, the electrode A2, the electrode B3 and the ion membrane 4 form a unit module 1;

[0054] On the front of the guide plate B11, avoiding the sealing area 102 of the ion membrane 4, a sealing membrane 5 is placed, and two groups of sealing holes are symmetrically arranged along the length direction of the sealing membrane 5, corresponding to and aligned with the liquid inlet 104 and the liquid outlet 103 set on the guide plate B11. The unit modules 1 are stacked and placed as needed, and finally pressed together to form a complete battery stack.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid flow battery stack, comprising a plurality of unit modules (1), characterized in that: The unit module (1) comprises a bipolar plate (20), a guide plate A (10), a guide plate B (11), an electrode A (2), an electrode B (3) and an ion membrane (4); The front side of the bipolar plate (20) is connected to the back side of the guide plate A (10) by laser welding, and the back side of the bipolar plate (20) is connected to the back side of the guide plate B (11) by laser welding. The central cut-out areas of the guide plate A (10) and the guide plate B (11) are reaction areas (201) for placing the electrode A (2) and the electrode B (3). The central shadow area (101) of the front side of the guide plate A (10) is a welding area of ​​the ion membrane (4).

2. A liquid flow battery stack according to claim 1, characterized in that: The electrode A (2) is located in a reaction zone (201) on the front side of the guide plate A (10), and the ion membrane (4) is welded to a shadow area (101) at the center of the front side of the guide plate A (10) by laser technology.

3. A liquid flow battery stack according to claim 1, characterized in that: The electrode B (3) is located in a second reaction zone (201) between the reverse side of the guide plate B (11) and the reverse side of the bipolar plate (20), so that the electrode A (2), the guide plate A (10), the bipolar plate (20), the guide plate B (11) and the electrode B (3) together constitute a unit module (1).

4. A liquid flow battery stack according to claim 1, characterized in that: A plurality of the unit modules (1) are stacked and arranged to form a battery stack, and the unit modules (1) are sealed by a sealing film (5) to form a complete battery stack.

5. A liquid flow battery stack according to claim 1, characterized in that: The liquid inlet (104) and the liquid outlet (103) of the guide plate A (10) and the guide plate B (11) are respectively aligned with the inlet channel hole (204) and the outlet channel hole (203) provided on the bipolar plate (20), and are fixed by laser welding to form an integral structure.

6. A liquid flow battery stack according to claim 1, characterized in that: The bipolar plate (20) is divided into a reaction zone (201) and an insulating zone (202), the reaction zone (201) is in contact with an electrode A (2) and an electrode B (3), the insulating zone (202) is welded to a guide plate A (10) and a guide plate B (11), and symmetrical outlet holes (203) and inlet holes (204) are provided along the length direction of the bipolar plate (20).

7. A liquid flow battery stack according to claim 1, characterized in that: The guide plate A (10) and the guide plate B (11) are made of PP / PE, with a light transmittance of 30%-80% and a thickness of 2.5-5 mm.

8. A liquid flow battery stack according to claim 4, characterized in that: The sealing film (5) is made of PP / PE and has a thickness of 0.1-1 mm, and is used for sealing between unit modules (1).

9. A liquid flow battery stack according to claim 1, characterized in that: The ion membrane (4) is a perfluorosulfonic acid ion membrane or a porous membrane, and is welded to the front center shadow area (101) of the guide plate A (10).

10. A sealing assembly process for a liquid flow battery stack, used for a liquid flow battery stack as claimed in claim 1, characterized in that: The following steps are involved: S1: placing the back side of the guide plate A (10) on the front side of the bipolar plate (20), and aligning the liquid inlet (104) and the liquid outlet (103) of the guide plate A (10) with the inlet channel hole (204) and the outlet channel hole (203) of the bipolar plate (20), respectively, and fixing the guide plate A (10) and the bipolar plate (20) by laser welding; S2: placing the reverse side of the guide plate B (11) on the reverse side of the bipolar plate (20), and aligning the liquid inlet (104) and the liquid outlet (103) of the guide plate B (11) with the inlet channel hole (204) and the outlet channel hole (203) of the bipolar plate (20), respectively, and fixing the guide plate B (11) and the bipolar plate (20) by laser welding; at this time, the guide plate A (10), the bipolar plate (20) and the guide plate B (11) form an integral component; S3: placing an electrode A (2) in a first reaction zone (201) between the back surface of the guide plate A (10) and the front surface of the bipolar plate (20), placing an ion membrane (4) in a central shadow area (101) on the front surface of the guide plate A (10), and welding the ion membrane (4) to the shadow area (101) by laser welding; S4: placing the guide plate B (11) of the integral component formed in S2 with its front side facing upward, and placing the electrode B (3) in the second reaction zone (201) between the reverse side of the guide plate B (11) and the reverse side of the bipolar plate (20); at this time, the bipolar plate (20), the guide plate A (10), the guide plate B (11), the electrode A (2), the electrode B (3) and the ion membrane (4) form a complete unit module (1); S5: On the front side of the guide plate B (11), avoiding the sealing area (102) of the ion membrane (4), a sealing membrane (5) is placed; along the length direction of the sealing membrane (5), two groups of sealing holes are symmetrically arranged, and the sealing holes correspond to the liquid inlet (104) and the liquid outlet (103) arranged on the guide plate B (11), and are aligned and placed; multiple unit modules (1) are stacked and placed as needed, and finally a complete battery stack is formed by pressing.

Images