阅读说明：本技术 一种液流电池 (Flow battery ) 是由 康嘉伦 陈威 树青 于 2019-11-13 设计创作，主要内容包括：本发明公开了一种液流电池,包括：本体,第一双极板、第二双极板；第一双极板和第二双极板结构相同；第一双极板包括：通道、位于通道上的电解液入口、电解液出口；通道包括：多个第一流道；第二流道,其一端与电解液入口相连,其上设置有多个第一连接口,每一个第一连接口分别与第一流道的一端相连；第三流道,其一端与电解液出口相连,其上设置有多个第二连接口,每一个第二连接口分别与第一流道的另一端相连。应用本发明实施例,设置具有周期性交替的波纹型流动通道,在相同的泵功损耗下,使流道内的电解液尽可能多地渗流进入电极参与反应,这将为在最大化传质和最小化压降之间优化设计提供极大的灵活性。(The invention discloses a flow battery, comprising: the bipolar plate comprises a body, a first bipolar plate and a second bipolar plate; the first bipolar plate and the second bipolar plate have the same structure; the first bipolar plate includes: the electrolyte inlet and the electrolyte outlet are positioned on the channel; the channel includes: a plurality of first flow passages; one end of the second flow channel is connected with the electrolyte inlet, a plurality of first connecting ports are arranged on the second flow channel, and each first connecting port is connected with one end of the first flow channel; and one end of the third flow channel is connected with the electrolyte outlet, a plurality of second connecting ports are arranged on the third flow channel, and each second connecting port is respectively connected with the other end of the first flow channel. By applying the embodiment of the invention, the periodically alternating corrugated flow channels are arranged, so that the electrolyte in the flow channel can seep into the electrode to participate in the reaction as much as possible under the same pumping power loss, and great flexibility is provided for the optimal design between the maximization of mass transfer and the minimization of pressure drop.)

1. A flow battery, comprising: the bipolar plate comprises a body, a positive end and a negative end which are positioned in the body, and a first bipolar plate and a second bipolar plate which are respectively positioned at the positive end and the negative end;

the first bipolar plate and the second bipolar plate are identical in structure;

the first bipolar plate includes: the electrolyte inlet and the electrolyte outlet are positioned on the channel;

the channel includes:

a plurality of first flow passages;

one end of the second flow channel is connected with the electrolyte inlet, a plurality of first connecting ports are arranged on the second flow channel, and each first connecting port is connected with one end of the first flow channel;

one end of the third flow channel is connected with the electrolyte outlet, a plurality of second connecting ports are arranged on the third flow channel, and each second connecting port is respectively connected with the other end of the first flow channel; when the electrolyte flows into the electrolyte inlet, the electrolyte flows into the plurality of first flow channels through the second flow channels, then flows through the third flow channels and flows out through the electrolyte outlet;

each of the plurality of first flow channels is a corrugated flow channel.

2. The flow battery of claim 1, wherein the first flow channel comprises: the electrolyte flow-through device comprises a contraction area and an expansion area which are arranged at intervals, wherein a first sectional area is smaller than a second sectional area, the first sectional area is the area of the contraction area, the second sectional area is the sectional area of the expansion area, and the first sectional area and the second sectional area are the areas corresponding to the sections which are perpendicular to the flow direction of the electrolyte.

3. A flow battery as claimed in claim 1 or 2 wherein said body comprises: the ion exchange membrane comprises a first end plate, a first electrode frame, a positive porous electrode, an ion exchange membrane, a negative porous electrode, a second electrode frame and a second end plate;

the first end plate, the first bipolar plate, the first electrode frame, the positive porous electrode, the ion exchange membrane, the negative porous electrode, the second electrode frame, the second bipolar plate and the second end plate are sequentially connected.

4. The flow battery as recited in claim 3, wherein the flow channels of the first bipolar plate or the second bipolar plate are disposed on a side proximate to the positive porous electrode or the negative porous electrode, respectively.

5. A flow battery as claimed in claim 2, wherein the cross-section of the contraction and expansion areas is rectangular in the vertical direction, the contraction and expansion areas are connected to each other by contraction and expansion ports, and the contraction or expansion ports are isosceles trapezoid tapered ports.

6. The flow battery as claimed in claim 2 wherein the first bipolar plate and/or the second bipolar plate is a non-porous graphite plate, and the non-porous graphite plate has a thickness of 2mm and an area size of 1.2cm x 1.2 cm.

7. The flow battery of claim 2, wherein expansion zones are disposed at the junctions of the first flow channel and the second and third flow channels as an inlet and an outlet.

8. The flow battery of claim 2, wherein the first flow channel is vertically disposed between the second flow channel and the third flow channel, and any one of the flow channels between the first flow channels is disposed in a parallel array.

Technical Field

The invention relates to the technical field of flow batteries in electrochemical energy storage technology, in particular to a flow battery.

Background

The redox flow battery is used as an efficient electrochemical energy storage technology and is applied to the fields related to storage and conversion of renewable energy sources. With the development of flow battery technology, the flow battery structure with the electrolyte distribution flow channels gradually replaces the flow-through type flow-field-free battery structure by virtue of more excellent battery performance.

Current flow field designs mainly include: parallel flow fields, serpentine flow fields and interdigitated flow fields. The current flow field design mainly adopts a straight channel to distribute electrolyte, which has the defects of improving the performance of the battery, and the mass transfer in the flow battery has the possibility of further enhancement.

Disclosure of Invention

The invention aims to provide a flow battery, which aims to provide a flow battery with periodically alternating corrugated flow channels, so that electrolyte in a flow channel can seep into an electrode to participate in reaction as much as possible under the same pumping power loss, and great flexibility is provided for the optimal design between the maximization of mass transfer and the minimization of pressure drop.

In order to achieve the above object, the present invention provides a flow battery including: the bipolar plate comprises a body, a positive end and a negative end which are positioned in the body, and a first bipolar plate and a second bipolar plate which are respectively positioned at the positive end and the negative end;

the first bipolar plate and the second bipolar plate are identical in structure;

the first bipolar plate includes: the electrolyte inlet and the electrolyte outlet are positioned on the channel;

the channel includes:

a plurality of first flow passages;

one end of the second flow channel is connected with the electrolyte inlet, a plurality of first connecting ports are arranged on the second flow channel, and each first connecting port is connected with one end of the first flow channel;

one end of the third flow channel is connected with the electrolyte outlet, a plurality of second connecting ports are arranged on the third flow channel, and each second connecting port is respectively connected with the other end of the first flow channel; when the electrolyte flows into the electrolyte inlet, the electrolyte flows into the plurality of first flow channels through the second flow channels, then flows through the third flow channels and flows out through the electrolyte outlet;

each of the plurality of first flow channels is a corrugated flow channel.

In one implementation, the first flow path includes: the electrolyte flow-through device comprises a contraction area and an expansion area which are arranged at intervals, wherein a first sectional area is smaller than a second sectional area, the first sectional area is the area of the contraction area, the second sectional area is the sectional area of the expansion area, and the first sectional area and the second sectional area are the areas corresponding to the sections which are perpendicular to the flow direction of the electrolyte.

In one implementation, the body includes: the ion exchange membrane comprises a first end plate, a first electrode frame, a positive porous electrode, an ion exchange membrane, a negative porous electrode, a second electrode frame and a second end plate;

the first end plate, the first bipolar plate, the first electrode frame, the positive porous electrode, the ion exchange membrane, the negative porous electrode, the second electrode frame, the second bipolar plate and the second end plate are sequentially connected.

In one implementation, the flow channels of the first bipolar plate or the second bipolar plate are respectively disposed at a side close to the positive porous electrode or the negative porous electrode.

In one implementation, the cross-section of the contraction area and the expansion area is rectangular in the vertical direction, the contraction area and the expansion area are connected with each other through a contraction opening and an expansion opening, and the contraction opening or the expansion opening is an isosceles trapezoid gradual opening.

In one implementation, the first bipolar plate and/or the second bipolar plate is a non-porous graphite plate, and the non-porous graphite plate has a thickness of 2mm and an area size of 1.2cm × 1.2 cm.

In one implementation, expansion zones are arranged at the joints of the first flow passage, the second flow passage and the third flow passage to serve as an inlet and an outlet.

In one implementation, the first flow channel is vertically disposed in the second flow channel and the third flow channel, and any one of the flow channels between the first flow channels is disposed in a parallel array.

The flow battery provided by the embodiment of the invention has the following beneficial effects:

(1) by providing corrugated flow channels with periodic alternation, the electrolyte in the flow channels can seep into the electrodes as much as possible to participate in the reaction under the same pumping power loss, which provides great flexibility for optimizing the design between maximizing the mass transfer and minimizing the pressure drop.

(2) Along with the periodic contraction and expansion of the electrolyte in the contraction area and the expansion area, the electrolyte in the flow channel forms flow blockage in the contraction area of the channel, and larger local pressure is caused, so that more electrolyte in the channel is forced to seep into the porous electrode, and the utilization efficiency of single circulation of the electrolyte is improved; in addition, the increase of the local resistance can also effectively increase the apparent speed in the porous region of the electrode, so that the mass transfer in the electrode is obviously enhanced, and the battery performance is obviously improved.

(3) The degree of contraction and expansion of the corrugated channel can be flexibly set by changing the areas of the contraction area and the expansion area, so that the flow mass transfer effect and the cell pressure drop loss reach the optimal balance, and great flexibility is provided for the optimal design between the maximum mass transfer and the minimum pressure drop.

Drawings

FIG. 1 is a schematic diagram of a corrugated channel structure according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a main structure of a flow battery according to an embodiment of the invention.

FIG. 3 is an enlarged schematic view of an expansion zone and a contraction zone in accordance with an embodiment of the present invention.

Fig. 4 is a schematic diagram of a prior art channel structure according to an embodiment of the present invention.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Fig. 1-4 the present invention provides a flow battery comprising: the bipolar plate comprises a body, a positive end and a negative end which are positioned in the body, and a first bipolar plate 12 and a second bipolar plate 22 which are respectively positioned at the positive end and the negative end;

the first bipolar plate 12 and the second bipolar plate 22 are identical in structure;

the first bipolar plate 12 includes: a channel, an electrolyte inlet 31 and an electrolyte outlet 32 on the channel;

the channel includes:

a plurality of first flow channels 100;

a second flow channel 110 having one end connected to the electrolyte inlet 31, and having a plurality of first connection ports, each of which is connected to one end of the first flow channel 100;

a third flow channel 120, one end of which is connected to the electrolyte outlet 32, and on which a plurality of second connection ports are provided, each of which is connected to the other end of the first flow channel 100; when the electrolyte flows into the electrolyte inlet, the electrolyte flows into the plurality of first flow channels 100 through the second flow channels 110, then flows through the third flow channels 120, and flows out through the electrolyte outlet 32;

each of the plurality of first flow channels 100 is a corrugated flow channel.

It should be noted that the corrugated flow field is parallel to the membrane plane and is seamlessly attached to the electrode. The electrolyte is pumped into the flow field inlets, flows into the second flow channels 110 through the electrolyte inlets 31, then flows into each first flow channel 100 through the first connection ports provided on the second flow channels 110, flows into the third flow channels 120 through the second connection ports of the third flow channels 120, and flows out through the electrolyte outlets 32 of the third flow channels 120. In this process, since the first flow channel 100 is a corrugated channel, the electrolyte can be uniformly distributed and forced to penetrate more into the electrode to participate in the reaction, wherein the electrode is the positive porous electrode 14 or the negative porous electrode 24.

As shown in fig. 2, in one implementation, the body includes: the ion exchange membrane comprises a first end plate 11, a first electrode frame 13, a positive porous electrode 14, an ion exchange membrane 5, a negative porous electrode 24, a second electrode frame 23 and a second end plate 21;

the first end plate 11, the first bipolar plate 12, the first electrode frame 13, the positive porous electrode 14, the ion exchange membrane 5, the negative porous electrode 24, the second electrode frame 23, the second bipolar plate 12, and the second end plate 21 are sequentially connected.

Further, for the corrugated flow channel, as shown in fig. 3, in one implementation, the first flow channel 100 includes: the electrolyte solution collector comprises a contraction area 101 and an expansion area 102 which are arranged at intervals, wherein a first sectional area is smaller than a second sectional area, the first sectional area is the area of the contraction area 101, the second sectional area is the sectional area of the expansion area 102, and the first sectional area and the second sectional area are the areas corresponding to the sections which are perpendicular to the flowing direction of the electrolyte solution.

It should be noted that the electrolyte in the flow channels will form flow obstructions in the constricted region 101 of the channels, and the electrolyte is forced to deflect more into the porous electrode to participate in the reaction in these regions by the formation of localized high pressure in the constricted region 101, and the superficial velocity in the electrode is significantly increased, and based on these two effects, the mass transfer of the electrolyte is significantly enhanced, which provides great flexibility in optimizing the design between maximizing mass transfer and minimizing pressure drop. The design of the invention can obviously improve the maximum current density and the maximum output power of the battery.

It can be understood that the corrugated channel flow field is processed on the surface of the first bipolar plate 12 or the second bipolar plate 22, unlike the conventional straight channel flow field, as shown in fig. 4, in the electrolyte delivery of a single cycle period, as much as possible more electrolyte seepage enters the electrode to participate in the reaction, so that the utilization efficiency of the single electrolyte can be improved, but this is balanced by the power loss from the pump. The corrugated channels alternate periodically between contracting and expanding from the electrolyte inlet to the outlet. The electrolyte is distributed to each corrugated branch channel pipe from the inlet main channel pipe and is gathered and recovered at the outlet main channel pipe, and when the electrolyte flows through the contraction port of the corrugated branch channel pipe, the electrolyte is forced to enter the positive porous electrode 14 and/or the negative porous electrode 24, so that more electrolyte is deflected to the electrodes to participate in reaction.

As shown in fig. 3, the cross section of the contraction area 101 and the expansion area 102 is rectangular in the vertical direction, the contraction area 101 and the expansion area 102 are connected with each other through a contraction opening and an expansion opening, and the contraction opening or the expansion opening is an isosceles trapezoid tapered opening. Where w is the flow path width of the constriction region 101, d is the flow path width of the expansion region 102, and L is the horizontal length of the constriction region 101 and the expansion region 102. In a specific implementation manner, the corrugated first channels 100 all have the same structural dimensions, and the channel width w of the contraction region 101 and the channel width d of the expansion region 102 can be appropriately adjusted according to actual conditions, for example, w is 400 μm, d is 600 μm, or w is 200 μm, d is 800 μm.

In this embodiment, the number of contraction and expansion cycles of the corrugated first flow channel 100 and the total area size of the corrugated flow field should be reasonably matched with the size of other relevant components of the battery structure, such as the electrode size and the bipolar plate size, and can be adjusted appropriately.

The flow channels of the first or second bipolar plate are disposed on a side near the positive or negative porous electrode 14 or 24, respectively.

The bipolar plate 2 is a non-porous graphite plate having a thickness of 2mm and an area size of 1.2cm × 1.2 cm. The corrugated flow channel flow field structure mainly comprises an inlet main channel pipe (a second flow channel 110), a plurality of corrugated branch channel pipes (a first flow channel 100) and an outlet main channel pipe (a third flow channel 120). Wherein the inlet main channel tube functions to distribute the electrolyte to each of the corrugated branch channel tubes, and the outlet main channel tube functions to collect and recover the reacted electrolyte, and the main channel tube channels (the second flow channel 110 and the third flow channel 120) have a depth of 600 μm and a width of 700 μm. Unlike conventional straight-branched channels, corrugated-type branched channels periodically alternate between contracting and expanding, wherein each corrugated-type branched channel functions to permeate the electrolyte into the porous electrode as much as possible to participate in the reaction, and the corrugated-type channel (first channel 100) has a wall thickness of 250 μm and a depth of 600 μm. According to the partially enlarged structure diagram of the corrugated flow channel shown in fig. 3, the flow channel width d of the expansion region 102 is set to 700 μm, the flow channel width w of the contraction region 101 is set to 300 μm, and the horizontal length L of the contraction region 101 and the expansion region 102 is set to 500 μm; the porous electrode 4 is made of carbon felt with a thickness of 2 mm.

In one implementation, the expansion region 102 is provided as an inlet and an outlet at the junction of the first flow passage 100 with the second flow passage 110 and the third flow passage 120.

In one implementation, the first flow channel 100 is vertically disposed on the second flow channel 110 and the third flow channel 120, and any one of the flow channels between the first flow channels 100 is disposed in a parallel array.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.