Flow battery bipolar plate with novel flow channel

Abstract

A flow battery bipolar plate with a novel flow channel relates to the technical field of flow batteries, and comprises a bipolar plate body and two groove areas which are arranged on the bipolar plate body in a central symmetry manner, the groove area comprises an infusion hole, a transverse groove and a plurality of longitudinal grooves; the plurality of longitudinal grooves in the two groove areas are alternately arranged in an interdigital manner and are not communicated with each other; the special-shaped grooves are communicated with the transverse grooves; the infusion hole is formed in the special-shaped groove; a fan-shaped shunting column, a rectangular shunting column and a triangular shunting column are arranged in the special-shaped groove; the longitudinal groove is S-shaped; a first extending part and a second extending part are arranged on the bipolar plate body. According to the utility model, the flow channel structure of the bipolar plate is improved, so that the speed of electrolyte entering the battery is effectively reduced, the electrolyte is distributed more uniformly, the internal concentration polarization is reduced, the overall voltage drop and the pumping power loss are reduced, and the electrochemical performance of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid flow batteries, in particular to a liquid flow battery bipolar plate with a novel flow channel. Background Art

[0002] Liquid flow battery is a high-performance energy storage device, which consists of end plates, bipolar plates, electrode frames, carbon felt and ion exchange membranes. Among them, the bipolar plate is not only one of the key components of the liquid flow battery, responsible for conductivity, but also controls the flow of the electrolyte. The flow channel structure on the bipolar plate directly affects the distribution uniformity and flow mass transfer capacity of the electrolyte, and thus affects the performance of the battery.

[0003] At present, most flow batteries use an interdigitated flow channel structure. Although this structure has certain advantages, it has some problems: the electrolyte is unevenly distributed in the inlet and outlet branches, which easily leads to concentration polarization and forms a large concentration overpotential. This not only increases pump loss and pressure loss inside the battery, but also reduces the overall electrochemical performance of the battery. Utility Model Content

[0004] In order to make up for the above-mentioned deficiencies, the utility model provides a bipolar plate for a liquid flow battery with a novel flow channel, aiming to improve the performance of the liquid flow battery by improving the bipolar plate flow channel structure.

[0005] The utility model is realized through the following technical scheme: a bipolar plate of a liquid flow battery with a novel flow channel, comprising a bipolar plate body and two groove areas centrally symmetrically arranged on one side of the bipolar plate body; the groove area comprises an infusion hole, a transverse groove and a plurality of longitudinal grooves; the plurality of longitudinal grooves in the two groove areas are alternately arranged in a forked finger shape and are not connected to each other, and the technical key points are: the groove area also comprises a special-shaped groove connected to the transverse groove; the infusion hole is arranged inside near one end of the special-shaped groove; a plurality of fan-shaped shunt columns are arranged around the infusion hole in the special-shaped groove; a plurality of rectangular shunt columns are arranged at intervals in the special-shaped groove; a triangular shunt column corresponding to the rectangular shunt column is arranged on one side of the special-shaped groove away from the infusion hole; the longitudinal groove is S-shaped; an expenditure part 1 and an expenditure part 2 are arranged at intervals at an end surface position of the bipolar plate body away from the infusion hole.

[0006] Furthermore, one end of the special-shaped groove close to the infusion hole is a rounded structure.

[0007] Furthermore, one end of the special-shaped groove away from the infusion hole is a bevel structure.

[0008] Furthermore, the number of the fan-shaped diverter columns is six, and the fan-shaped angle of the fan-shaped diverter columns is 30 degrees.

[0009] Furthermore, positioning holes are symmetrically arranged on the edge of the bipolar plate body.

[0010] Furthermore, the heights of the first and second expenditure parts are the same, and the width of the first expenditure part is twice the width of the second expenditure part.

[0011] Beneficial effects and features of the utility model:

[0012] Compared with the prior art, the utility model increases special-shaped grooves, rectangular diverter columns, triangular diverter columns and fan-shaped diverter columns, so that the electrolyte generates a certain resistance after flowing in and then is evenly diverted, thereby reducing the flow rate of the electrolyte; the contact area between the electrolyte and the carbon felt is increased by changing the longitudinal grooves into S-shaped flow channels; the internal concentration polarization is effectively reduced, while the pressure drop and pump power loss are reduced, the redox reaction is promoted, and the electrochemical performance of the battery is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a main schematic diagram of the utility model;

[0014] Figure 2 for Figure 1 A magnified schematic diagram of part A;

[0015] Figure 3 It is a schematic diagram of the main view of a conventional interdigitated channel bipolar plate;

[0016] Figure 4 A comparison diagram of pressure drop and pump loss between the utility model and the prior art;

[0017] Figure 5 A comparison diagram of polarization curves and power densities of the utility model and the prior art;

[0018] Figure 6 It is a three-dimensional schematic diagram of the utility model.

[0019] The main parts serial number description in the figure is as follows: 1. Bipolar plate body; 2. Special-shaped groove; 201. Rectangular diverter column; 202. Triangular diverter column; 203. Fan-shaped diverter column; 204. Rounded corner structure; 205. Bevel structure; 3. Infusion hole; 4. Horizontal groove; 5. Longitudinal groove; 6. Exit part one; 7. Exit part two; 8. Positioning hole.

[0020] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the drawings required for use in the embodiment will be briefly introduced below. Obviously, the drawings described below are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work. The other drawings obtained are all within the protection scope required by the utility model. DETAILED DESCRIPTION

[0021] The following combination Figure 1-6 , the contents of the utility model are described in detail through specific embodiments. Example

[0022] The liquid flow battery bipolar plate of the novel flow channel comprises a bipolar plate body 1 and two groove areas centrally symmetrically arranged on one side of the bipolar plate body; the groove area comprises an infusion hole 3, a transverse groove 4 and a plurality of longitudinal grooves 5; the plurality of longitudinal grooves in the two groove areas are alternately arranged in a forked finger shape and are not interconnected, wherein: the groove area also comprises a special-shaped groove 2 connected to the transverse groove; the infusion hole is arranged inside the special-shaped groove near one end; a plurality of fan-shaped diversion columns 203 are arranged around the infusion hole in the special-shaped groove; a plurality of rectangular diversion columns 201 are arranged at intervals in the special-shaped groove; a triangular diversion column 202 corresponding to the rectangular diversion column is arranged on the side of the special-shaped groove away from the infusion hole, the rectangular diversion column and the triangular diversion column are arranged at equal intervals in the horizontal direction, and the rectangular diversion column and the triangular diversion column divide the special-shaped groove into a plurality of flow channel grooves with the same width, the purpose of which is to make the electrolyte evenly diverted after a certain resistance is generated, thereby reducing the flow rate of the electrolyte. The longitudinal groove is S-shaped, the purpose is to make the electrolyte flow rate more consistent, while increasing the contact area with the carbon felt. An outlet part 1 6 and an outlet part 2 7 are arranged at intervals at one end of the bipolar plate body away from the infusion hole, and the outlet part 1 and the outlet part 2 are used to connect with the battery detection system.

[0023] Preferably, one end of the special-shaped groove close to the infusion hole is a rounded structure 204 .

[0024] Preferably, one end of the special-shaped groove away from the infusion hole is a bevel structure 205 .

[0025] Preferably, the number of the fan-shaped diverter columns is six, and the fan-shaped angle of the fan-shaped diverter columns is 30 degrees.

[0026] Preferably, positioning holes 8 are symmetrically arranged on the edge of the bipolar plate body, and the positioning holes are used to connect and fix the bipolar plate to the electrode frame by bolts.

[0027] Preferably, the heights of the first and second outgoing portions are the same, and the width of the first outgoing portion is twice the width of the second outgoing portion.

[0028] The depths of the special-shaped grooves, the transverse grooves and the longitudinal grooves are the same; the rectangular diverter columns, the triangular diverter columns and the fan-shaped diverter columns are in the same horizontal plane as the side surfaces of the bipolar plate body.

[0029] The bipolar plate body is a graphite composite bipolar plate, and its length-to-width ratio is 4:3.

[0030] To summarize, the electrolyte enters the infusion hole of one of the groove areas and is then decelerated and diverted to the transverse grooves through the fan-shaped diversion column, the rectangular diversion column, and the triangular diversion column, and then enters multiple S-shaped longitudinal grooves through the transverse grooves, and finally flows out through the longitudinal grooves, transverse grooves, and infusion holes of another groove area in sequence, completing a cycle.

[0031] Experimental data

[0032] In order to verify the effect of the utility model, the following experiments were carried out:

[0033] The all-vanadium liquid flow battery is assembled using the new flow channel bipolar plate of the utility model and the traditional interdigital flow channel bipolar plate. The all-vanadium liquid flow battery includes an end plate, a bipolar plate, an electrode frame, an electrode (carbon felt) placed in the middle of the electrode frame, and an exchange membrane. The test was carried out using the Xinwei battery detection system, and the current density was set to 160mA / cm².

[0034] Table 1: Performance comparison between the new channel bipolar plate and the traditional interdigitated channel bipolar plate

[0035] As shown in Table 1: The coulombic efficiency (CE), energy efficiency (EE), and voltage efficiency (VE) of the new flow channel bipolar plate are significantly higher than those of the traditional interdigitated flow channel bipolar plate. The voltage efficiency is increased by about 2.5%, the energy efficiency is increased by about 4%, and the coulombic efficiency is increased by about 2%, proving that the new flow channel effectively improves the electrochemical performance.

[0036] like Figure 5 It is described that: under the same flow rate, the pressure drop and pump loss of the new flow channel are significantly lower than those of the traditional interdigitated flow channel. The new flow channel effectively reduces the internal concentration polarization, promotes the redox reaction on the electrode surface, and improves the electrochemical performance of the battery.

[0037] like Figure 6 It is described that: under the same current density, the voltage and power density of the new flow channel are significantly better than those of the traditional interdigitated flow channel, and the increase in voltage and power density effectively improves the electrochemical performance.

[0038] The results of the experimental data show that the structural design of the new flow channel liquid flow battery bipolar plate effectively reduces the speed at which the electrolyte enters the battery compared to the traditional interdigitated flow channel bipolar plate structure, making the electrolyte distribution more uniform, reducing internal concentration polarization, and at the same time reducing the overall pressure drop and pump power loss, thereby improving the electrochemical performance of the battery.

Claims

1. A new type of flow channel liquid flow battery bipolar plate, comprising a bipolar plate body and two groove areas centrally symmetrically arranged on one side of the bipolar plate body; the groove area comprises a liquid infusion hole, a transverse groove and a plurality of longitudinal grooves; the plurality of longitudinal grooves in the two groove areas are alternately arranged in a forked shape and are not interconnected, characterized in that: The groove area also includes a special-shaped groove connected to the transverse groove; the infusion hole is arranged inside the special-shaped groove near one end; a plurality of fan-shaped diversion columns are arranged around the infusion hole in the special-shaped groove; a plurality of rectangular diversion columns are arranged at intervals in the special-shaped groove; a triangular diversion column corresponding to the rectangular diversion column is arranged on the side of the special-shaped groove away from the infusion hole; the longitudinal groove is S-shaped; and an expenditure portion 1 and an expenditure portion 2 are arranged at intervals at an end surface of the bipolar plate body away from the infusion hole.

2. The bipolar plate for a flow battery with a novel flow channel according to claim 1, characterized in that: One end of the special-shaped groove close to the infusion hole is a rounded structure.

3. The bipolar plate for a liquid flow battery with a novel flow channel according to claim 1, characterized in that: The end of the special-shaped groove away from the infusion hole is a bevel structure.

4. The bipolar plate for a flow battery with a novel flow channel according to claim 1, characterized in that: The number of the fan-shaped diverter columns is six, and the fan-shaped angle of the fan-shaped diverter columns is 30 degrees.

5. The bipolar plate for a flow battery with a novel flow channel according to claim 1, characterized in that: Positioning holes are symmetrically arranged on the edge of the bipolar plate body.

6. The bipolar plate for a liquid flow battery with a novel flow channel according to claim 1, characterized in that: The first and second outgoing portions have the same height, and the first outgoing portion has a width that is twice the width of the second outgoing portion.

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