Flow cell flow channel bipolar plate with conductive center and insulated edge

Abstract

The utility model belongs to the technical field of flow battery bipolar plates, and particularly relates to a flow battery flow channel bipolar plate with a conductive center and an insulated edge. The flow cell flow channel bipolar plate with the conductive center and the insulated edge comprises a conductive substrate which is composed of an electrochemical reaction area and an insulation area; the insulation area is located on the periphery of the electrochemical reaction area, and the electrochemical reaction area and the insulation area are integrally formed; a plurality of runners are arranged on the surface of the electrochemical reaction area; the flow channels of the upper and lower electrochemical reaction areas of the conductive substrate are mutually staggered; the flexible graphite film is adhered to the surface of the non-flow channel of the electrochemical reaction area; the geometric dimension of the flexible graphite film is the same as the surface dimension of the non-flow channel of the electrochemical reaction area; and the corrosion-resistant insulating layer is arranged on the insulating region. According to the bipolar plate, the flow channel is deepened, the thickness of the bipolar plate is not obviously increased, the corrosion resistance is high, electrolyte leakage can be effectively prevented, the sealing performance and safety of the battery are improved, the corrosion risk is reduced, and the service life of the battery is prolonged.

Description

Technical Field

[0001] This utility model belongs to the technical field of flow battery bipolar plates, specifically relating to a flow battery flow channel bipolar plate with a central conductive and edge insulated design. Background Technology

[0002] Flow batteries, as high-performance electrochemical energy storage devices, have been widely used in large-scale energy storage systems due to their advantages such as high energy conversion efficiency, long cycle life, and deep charge / discharge capability. Bipolar plates are one of the key components in flow batteries; they not only separate different electrolytes but also play a crucial role in conducting current and supporting the battery structure.

[0003] Carbon-based composite bipolar plates are one of the main technical routes for flow battery bipolar plates. In these plates, the electrochemical reaction zone and the non-electrochemical reaction zone are mostly made of homogeneous material. The main technical problems are poor conductivity in the electrochemical reaction zone, susceptibility to electrochemical corrosion in the non-electrochemical reaction zone, and increased bipolar plate thickness due to increased channel depth. A traditional method to improve the conductivity of the electrochemical reaction zone is to increase the conductive filler content of the bipolar plate; however, this method reduces the mechanical properties of the bipolar plate. The main methods to improve the corrosion resistance of the non-electrochemical reaction zone are to replace it with an insulating material or to cover it with an insulating film. Replacing it with an insulating material can easily lead to weak bonding between the materials in the electrochemical reaction zone, causing separation during battery operation. Covering it with an insulating film can easily lead to two situations: first, if the insulating film is thin (below 100μm), for welded flow batteries, the insulating film may be damaged during the welding process, directly exposing the conductive substrate; second, if the insulating film is thick, it significantly increases the battery thickness and leads to poorer contact between the bipolar plate and the electrodes. Taking a 100μm insulating film as an example, the overall thickness of the stack increases by 24mm for a standard 60-cell stack. In addition, since the channel depth increases the thickness of the bipolar plate, in practical applications, a trade-off usually needs to be made between increasing the channel depth and reducing the thickness of the bipolar plate.

[0004] Therefore, there is a need for carbon-based composite bipolar plates that not only provide insulation in the non-electrochemical reaction zone, but also are corrosion-resistant, weldable, and do not increase the bipolar plate thickness; improve the conductivity in the electrochemical reaction zone without affecting the mechanical properties of the bipolar plate; and increase the flow channel depth while minimizing the increase in bipolar plate thickness. Utility Model Content

[0005] This invention provides a flow battery bipolar plate with a centrally conductive and edge-insulated flow channel. This invention addresses the shortcomings of existing bipolar plates, such as poor conductivity in the electrochemical reaction zone and susceptibility to electrochemical corrosion in the non-electrochemical reaction zone. This bipolar plate increases the flow channel depth while minimizing the increase in bipolar plate thickness, providing a more reliable solution for the large-scale application of flow batteries.

[0006] To achieve the above objectives, the present invention provides the following technical solution.

[0007] A flow battery bipolar plate with a centrally conductive and edge-insulated flow channel includes:

[0008] The conductive substrate 1 is composed of an electrochemical reaction region 101 and an insulating region 102. The insulating region 102 is located around the electrochemical reaction region 101, and the electrochemical reaction region 101 and the insulating region 102 are integrally formed. Multiple flow channels 103 are provided on the surface of the electrochemical reaction region 101. The flow channels 103 of the upper and lower electrochemical reaction regions 101 of the conductive substrate 1 are interwoven.

[0009] A flexible graphite film 2 is adhered to the surface of the non-flow channel 103 of the electrochemical reaction zone 101; the geometric dimensions of the flexible graphite film 2 are the same as the surface dimensions of the non-flow channel 103 of the electrochemical reaction zone 101.

[0010] A corrosion-resistant insulating layer 3 is disposed on the insulating area 102.

[0011] Furthermore, the conductive substrate 1 obtains the insulating region 102 by thinning the edge layers on both sides; the thinning depth is the difference in thickness between the corrosion-resistant insulating layer 3 and the flexible graphite film 2; the thinning width is consistent with the width of the corrosion-resistant insulating layer 3.

[0012] Furthermore, the height of the corrosion-resistant insulating layer 3 on the insulating region 102 is consistent with the height of the flexible graphite film 2 adhered to the electrochemical reaction region 101.

[0013] Furthermore, the depth of the flow channel 103 is greater than half the thickness of the conductive substrate 1.

[0014] Furthermore, the flow channels 103 are parallel to each other.

[0015] Furthermore, the conductive substrate 1 is a carbon composite material with high strength and low electrical conductivity.

[0016] Furthermore, the carbon composite material is composed of thermoplastic resin and carbon-based conductive filler.

[0017] Furthermore, the flexible graphite film 2 is a natural graphite paper or artificial graphite film with low strength and high electrical conductivity.

[0018] Furthermore, the corrosion-resistant insulating layer 3 is made of thermoplastic resin without the addition of conductive fillers.

[0019] Compared with the prior art, the present invention has the following beneficial effects.

[0020] 1. The bipolar plates adopt a partitioned design. The electrochemical reaction zone has high conductivity, which helps to improve the charge and discharge efficiency of the flow battery. The non-electrochemical reaction zone adopts an insulating design to improve corrosion resistance and maintains the same thickness as the electrochemical reaction zone.

[0021] 2. The composite structure design of the bipolar plate and the supporting role of the non-electrochemical reaction zone ensure the mechanical strength and structural stability of the bipolar plate, enabling it to maintain good performance during high-power charging and discharging and long-term operation, and reducing mechanical deformation and poor contact problems.

[0022] 3. The non-electrochemical reaction zone of the bipolar plate meets the requirements for welding and sealing, has high corrosion resistance, can effectively prevent electrolyte leakage, improve battery sealing performance and safety, reduce corrosion risk, and extend battery life.

[0023] 4. The bipolar plate adopts an interlaced flow channel design on both sides, which allows the flow channel depth to be greater than half the thickness of the conductive substrate, thus achieving the goal of deepening the flow channel without significantly increasing the thickness of the bipolar plate. Attached Figure Description

[0024] Figure 1 This is a top view of the conductive substrate of Embodiment 1 of this utility model.

[0025] Figure 2 This is a simplified cross-sectional view of the bipolar plate in Embodiment 1 of this utility model.

[0026] Figure 3 This is a top view of the bipolar plate of Embodiment 1 of this utility model.

[0027] Among them: 1. conductive substrate, 101. electrochemical reaction zone, 102. insulating zone, 103. flow channel, 2. flexible graphite film, 3. corrosion resistant insulating layer. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example 1.

[0030] like Figures 1-3 As shown, this embodiment provides a flow battery bipolar plate with a centrally conductive and edge-insulated flow channel, comprising:

[0031] The conductive substrate 1 consists of an electrochemical reaction area 101 and an insulating area 102; the insulating area 102 is located around the electrochemical reaction area 101, and the electrochemical reaction area 101 and the insulating area 102 are integrally formed; multiple flow channels 103 are arranged on the surface of the electrochemical reaction area 101; the flow channels 103 of the electrochemical reaction areas 101 on the upper and lower sides of the conductive substrate 1 are staggered with each other; the flexible graphite film 2 is adhered to the surface of the electrochemical reaction area 101 that is not the flow channel 103; the geometric size of the flexible graphite film 2 is the same as the surface size of the non-flow channel 103 of the electrochemical reaction area 101; the corrosion-resistant insulating layer 3 is arranged on the insulating area 102 and is in a "return" shape. The size of the bipolar plate is 52 cm × 32 cm × 1 mm, the size of the conductive substrate 1 is 52 cm × 32 cm × 0.8 mm, the area of the electrochemical reaction area 101 is 50 cm × 30 cm, and the width of the insulating area 102 is 1 cm. The bipolar plate adopts a partition design. The electrochemical reaction area has high conductivity, which helps to improve the charge and discharge efficiency of the flow battery; the insulating area (non-electrochemical reaction area) adopts an insulating design to improve corrosion resistance.

[0032] In this embodiment, the conductive substrate 1 obtains the insulating area 102 by thinning the edge layers on both the front and back sides; the thinning depth is the thickness difference between the corrosion-resistant insulating layer 3 and the flexible graphite film 2; the thinning width is consistent with the width of the corrosion-resistant insulating layer 3; the height of the corrosion-resistant insulating layer 3 arranged on the insulating area 102 is the same as the height of the flexible graphite film 2 adhered to the electrochemical reaction area 101. The thickness of the corrosion-resistant insulating layer 3 is 0.3 mm, and the thickness of the flexible graphite film 2 is 0.1 mm. The composite structure design of the bipolar plate and the supporting effect of the non-electrochemical reaction area (the bipolar plates have the same height) ensure the mechanical strength and structural stability of the bipolar plate, enabling it to maintain good performance during high-power charge and discharge and long-term operation, and reducing mechanical deformation and poor contact problems.

[0033] In this embodiment, the flow channels 103 are parallel to each other, the depth of the flow channels 103 is greater than half of the thickness of the conductive substrate 1, and the depth of the flow channels 103 is 0.5 mm. The flow channels on both sides of the bipolar plate adopt a staggered design, so that the depth of the flow channels can be greater than half of the thickness of the conductive substrate, thus achieving the deepening of the flow channels without significantly increasing the thickness of the bipolar plate.

[0034] In this embodiment, the conductive substrate 1 is made of a composite of thermoplastic PP resin and carbon-based conductive fillers, with high strength and low conductivity, and is used to maintain the good mechanical properties of the bipolar plate. Further, the flexible graphite film 2 is an artificial graphite film with low strength and high conductivity, and is used to increase the conductivity of the bipolar plate. The corrosion-resistant insulating layer 3 is made of PP material without adding conductive fillers.

Claims

1. A bipolar plate for a flow battery with a centrally conductive and edge-insulated flow channel, characterized in that, include: The conductive substrate (1) is composed of an electrochemical reaction region (101) and an insulating region (102); the insulating region (102) is located around the electrochemical reaction region (101), and the electrochemical reaction region (101) and the insulating region (102) are integrally formed; a plurality of flow channels (103) are provided on the surface of the electrochemical reaction region (101); the flow channels (103) of the upper and lower electrochemical reaction regions (101) of the conductive substrate (1) are intersected with each other; A flexible graphite film (2) is adhered to the surface of the non-channel (103) of the electrochemical reaction zone (101); the geometric dimensions of the flexible graphite film (2) are the same as the surface dimensions of the non-channel (103) of the electrochemical reaction zone (101); A corrosion-resistant insulating layer (3) is disposed on the insulating area (102).

2. The bipolar plate of the flow battery with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The conductive substrate (1) obtains an insulating region (102) by thinning the edge layers on both sides; the thinning depth is the difference in thickness between the corrosion-resistant insulating layer (3) and the flexible graphite film (2); the thinning width is consistent with the width of the corrosion-resistant insulating layer (3).

3. The bipolar plate of the flow battery with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The corrosion-resistant insulating layer (3) is positioned at the same height as the flexible graphite film (2) adhered to in the electrochemical reaction zone (101) on the insulating area (102).

4. The flow battery bipolar plate with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The depth of the flow channel (103) is greater than half the thickness of the conductive substrate (1).

5. The flow battery bipolar plate with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The flow channels (103) are parallel to each other.

6. The flow battery bipolar plate with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The conductive substrate (1) is a high-strength, low-conductivity carbon composite material.

7. The flow battery bipolar plate with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The flexible graphite film (2) is a natural graphite paper or an artificial graphite film with low strength and high electrical conductivity.

8. The flow battery bipolar plate with a centrally conductive and edge-insulated flow channel according to claim 1, characterized in that, The corrosion-resistant insulating layer (3) is made of thermoplastic resin without added conductive fillers.

Images