CN210224178U

CN210224178U - Electrode assembly

Info

Publication number: CN210224178U
Application number: CN201920783623.9U
Authority: CN
Inventors: Jijun Chen; 陈继军; Shengzhi Tang; 唐升智; Lin Wu; 伍林; Shu Zhang; 张庶
Original assignee: Leshan Weili To Energy Co Ltd
Current assignee: Leshan Weili To Energy Co Ltd
Priority date: 2019-05-28
Filing date: 2019-05-28
Publication date: 2020-03-31
Anticipated expiration: 2029-05-28

Abstract

The utility model discloses an electrode assembly, including bipolar plate, bipolar plate is fixed by mated polymer framework centre gripping, and is mated through the fusion welding between the polymer framework. The frame body made of polymer materials is used for clamping and fixing the bipolar plate, the materials on the two sides of the bipolar plate are welded into a whole through melting, the electrolyte is sealed and isolated by the overall structure of the polymer frame body, the sealing ring is removed, and the leakage problem caused by aging of the sealing ring is avoided.

Description

Electrode assembly

Technical Field

The utility model relates to a flow battery field, concretely relates to electrode subassembly.

Background

Flow batteries are a secondary battery technology in which the active material is present in a liquid electrolyte. The flow battery is composed of two liquid electrolytes stored in an external tank, and is conveyed into the battery through a pipeline under the pushing of a circulating pump according to needs, flows through a galvanic pile and generates electrochemical reaction, so that electrons pass through a membrane in the battery back and forth to convert chemical energy and electric energy, and thus, the storage and the release of the electric energy are realized.

The minimum working unit of the flow battery is an electrode assembly taking a bipolar plate as a core, and fixing frames are arranged on two sides of the bipolar plate for clamping and sealing to form the electrode assembly with a multilayer composite structure. After the electrode assemblies are stacked, the electrode assemblies are fixed from the ends by fasteners and sealed plates are punched on the outer peripheral surfaces of the electrode assemblies, so that the electrode stack for performing electrochemical reaction in the flow battery is formed.

The sealing ring is arranged around the bipolar plate at the position between the fixing frames in order to avoid electrolyte leakage of the conventional electrode assembly, and the fixing frames extrude the sealing ring during pile assembly, so that the electrolyte is sealed and isolated. The problem is that the electrolyte is often corrosive, and the sealing ring is easy to age after long-term use; meanwhile, the electrolyte has certain pressure under the action of the circulating pump. When the sealing ring is corroded and aged, the joint of the fixing frame cannot be continuously and stably sealed, and when electrolyte passes through the electrode assembly, the sealing ring is easily broken by pressure applied to the fixing frame structure, so that the sealing ring leaks from a gap of the joint, and the flow battery cannot normally work.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides an electrode assembly, which uses a frame made of a polymer material to clamp and fix a bipolar plate, wherein the materials on two sides of the bipolar plate are welded together by melting, the electrolyte is sealed and isolated by the overall structure of the polymer frame, a sealing ring is removed, and the leakage problem caused by aging of the sealing ring is avoided.

For solving above technical problem, the utility model provides a technical scheme is an electrode subassembly, including bipolar plate, bipolar plate is fixed by mated polymer framework centre gripping, and is mated through the fusion welding between the polymer framework.

Preferably, a first laser welding layer is arranged between the polymer frame bodies and is used for melting the polymer frame bodies in contact with the first laser welding layer; the first laser weld layer is disposed around the bipolar plate.

Preferably, the first laser welding layer is a light absorbing layer in a sheet shape or a light absorbing material coating coated on the polymer frame body.

Preferably, a flow guide frame for guiding the flow of the electrolyte is arranged on one side of the polymer frame body, which faces away from the bipolar plate, and the flow guide frame and the polymer frame body are welded in a melting mode.

Preferably, a second laser welding layer is arranged between the guide frame and the polymer frame body, and the second laser welding layer is used for melting the guide frame and the polymer frame body which are in contact with the second laser welding layer.

Preferably, the middle of the flow guide frame is provided with a hollow area, the flow guide frame is provided with at least two flow channels and an electrolyte conveying port, and the flow channels are respectively communicated with the hollow area and the electrolyte conveying port.

Preferably, the flow passages are symmetrically arranged around the center of the hollow area, and a connecting line of the electrolyte delivery openings passes through the center of the hollow area.

Preferably, the hollow area is rectangular, and the connection position of the flow channel and the hollow area is respectively located at the midpoint of the top edge and the bottom edge of the hollow area.

Preferably, the flow channel positions of the flow guide frames positioned at the two sides of the bipolar plate are in mirror symmetry.

Compared with the prior art, the application has the beneficial effects that:

fusion welding is carried out between the polymer frame bodies to fixedly clamp the bipolar plate, the two polymer frame bodies are welded into a whole, a sealing ring is not required to be arranged to plug a gap, the phenomenon of sealing ring aging and leakage is avoided, and the sealing performance of the electrode assembly is effectively improved.

Set up the laser welding layer between the polymer framework, laser penetrates the polymer framework and shines on the laser welding layer, and the laser welding layer generates heat and makes the polymer framework melt, has guaranteed welding position's accuracy, increases welded structural strength.

The runners are symmetrically arranged relative to the hollow area, so that electrolyte flowing out of the runners can fully pass through the bipolar plate, the contact area is increased, and the electrochemical reaction efficiency of the flow battery is ensured.

Drawings

Fig. 1 is a schematic structural view of an electrode assembly according to the present invention;

fig. 2 is a schematic view of the electrode assembly according to the present invention.

Reference numerals: the bipolar plate comprises a bipolar plate 1, a polymer frame body 2, a first laser welding layer 31, a second laser welding layer 32, a flow guide frame 4, a hollow area 41, a flow channel 42, an electrolyte delivery port 43, an ion exchange membrane 51 and a carbon felt 52.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1, an embodiment of the present invention provides an electrode assembly, including a bipolar plate 1, the bipolar plate 1 is clamped and fixed by paired polymer frames 2, a first laser welding layer 31 is disposed between the paired polymer frames 2, and the first laser welding layer 31 is disposed around the bipolar plate 1. In the present embodiment, the first laser welding layer 31 is a light absorbing layer in a sheet shape for melting the polymer frame body 2 in contact therewith; in other embodiments, a person skilled in the art can also apply a light absorbing material coating on the polymer frame 2 or otherwise dispose the first laser welding layer 31 between the polymer frames 1 based on understanding the present disclosure.

A diversion frame 4 for guiding the electrolyte to flow is arranged on one side of the polymer frame body 2, which is opposite to the bipolar plate 1, a second laser welding layer 32 is arranged between the diversion frame 4 and the polymer frame body 2, and the second laser welding layer 32 is used for melting the diversion frame 4 and the polymer frame body 2 which are in contact with the second laser welding layer. The middle of the flow guide frame 4 is provided with a hollow area 41, the flow guide frame 4 is provided with two flow channels 42 and an electrolyte conveying opening 43, and the flow channels 42 are respectively communicated with the hollow area 41 and the electrolyte conveying opening 43. The flow channels 42 are symmetrically arranged about the center of the hollow area 41, and the connecting line of the electrolyte delivery ports 43 passes through the center of the hollow area 41. The hollow area 41 is rectangular, and the connection point of the flow channel 42 and the hollow area 43 is respectively located at the middle point of the top edge and the bottom edge of the hollow area 43. The flow channels 42 of the flow guiding frames 4 on both sides of the bipolar plate 1 are in mirror symmetry.

In the assembly of the electrode assembly provided in this embodiment, the bipolar plate 1 is sandwiched by the pair of polymer frames 2, and the first laser welding layer 31 is disposed between the polymer frames 2, and the first laser welding layer 31 is disposed around the bipolar plate 1. Near-infrared laser is adopted for welding, the laser penetrates through the polymer frame bodies 2 and then irradiates on the first welding layers 31, the first welding layers 31 absorb energy and generate heat, and adjacent polymer frame bodies 2 are welded into a whole through melting. The first welding layer 31 is arranged around the bipolar plate 1, and after the laser moves along the first welding layer 31 to complete fusion welding, the welding can be completely closed, so that no gap is left between the polymer frame bodies 2 clamping the bipolar plate 1, and a good sealing effect is realized. And arranging the flow guide frame 4 outside the polymer frame body 2 in the same way, and carrying out fusion welding on the polymer frame body 2 and the flow guide frame 4 through the second laser welding layer 32 to finish the preparation of the electrode assembly.

Referring to fig. 2, when the electrode assemblies provided in this embodiment are used, they are stacked in sequence, and a carbon felt 52, an ion exchange membrane 51, and a carbon felt 52 are sequentially disposed between adjacent electrode assemblies. In order to facilitate the display of the laminated structure, the electrode assembly, the ion exchange membrane 51 and the carbon felt 52 are separately arranged, and in actual use, the laminated structures are closely attached to each other. The layer structure between the bipolar plates 1 of two adjacent electrode assemblies and the two opposite electrodes on the two bipolar plates 1 form a single cell structure of the flow battery. The electrolyte is injected through the flow guide frame 4 and generates electric energy through electrochemical reaction on the ion exchange membrane 51, so that the power generation function of the flow battery is realized.

In this embodiment, the polymer frame 2 is made of a thermoplastic polymer resin material, preferably high-density polyethylene, and the laser has a good transmission capability to the material, so that the first welding layer 31 can absorb a large amount of laser energy, thereby improving welding efficiency and quality. On the basis of understanding the technical scheme, the technical scheme can also adopt thermoplastic organic materials such as polyester, polyolefin, polyketone, ABS, PBT and the like, without influencing the implementation of the technical scheme.

According to the electrode assembly provided by the embodiment, gapless sealing is realized between the polymer frame bodies 2 and between the polymer frame bodies and the flow guide frame 4 through fusion welding, the problem of aging and leakage of the sealing ring is avoided, and the use stability of the liquid flow electrode assembly is effectively improved. Set up the laser welding layer as welded heat source, guaranteed the accuracy nature of heating position, reduced the restriction to 2 materials of polymer framework, the structure of fusion welding department is more stable firm. The symmetrically arranged flow channels 42 communicating with the hollowed-out area 41 enable better coverage of the electrolyte over the bipolar plate, thus ensuring higher electrochemical reaction efficiency.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and enhancements can be made without departing from the spirit and scope of the invention, and such modifications and enhancements are intended to be within the scope of the invention.

Claims

1. An electrode assembly comprising a bipolar plate, wherein the bipolar plate is clamped and fixed by a pair of polymer frame bodies, and the pair of polymer frame bodies are welded by fusion; a first laser welding layer is arranged between the polymer frame bodies and is used for melting the polymer frame bodies in contact with the first laser welding layer; the first laser welded layer is disposed around the bipolar plate; the first laser welding layer is a flaky light absorption layer or a light absorption material coating coated on the polymer frame body.

2. The electrode assembly of claim 1, wherein a side of the polymer frame body facing away from the bipolar plate is provided with a flow guiding frame for guiding the flow of the electrolyte, and the flow guiding frame and the polymer frame body are welded by fusion.

3. The electrode assembly of claim 2, wherein a second laser welded layer is disposed between the leadframe and the polymer frame for melting the leadframe and the polymer frame in contact therewith.

4. The electrode assembly of claim 2, wherein the flow frame has a hollow area in the middle, and the flow frame has at least two flow channels and an electrolyte delivery port, and the flow channels are respectively connected to the hollow area and the electrolyte delivery port.

5. The electrode assembly of claim 4, wherein the flow channels are symmetrically arranged about a center of the hollowed-out region, and the connection line of the electrolyte delivery ports passes through the center of the hollowed-out region.

6. The electrode assembly of claim 5, wherein the hollowed-out region is rectangular, and the junction between the flow channel and the hollowed-out region is located at the midpoint of the top edge and the bottom edge of the hollowed-out region, respectively.

7. The electrode assembly of claim 4, wherein the flow channel positions of the flow frames on both sides of the bipolar plate are mirror images.