Flow battery with multiple modules connected in series

Abstract

According to the flow battery, a single battery is divided into a plurality of battery modules which are connected in series, and electrolyte in a liquid storage device enters each battery module simultaneously through a liquid conveying pipeline, so that the distance between liquid feeding and liquid discharging can be reduced, the on-way resistance of the electrolyte is further reduced, and the service life of the battery is prolonged. And the lift of the delivery pump can be reduced. Moreover, the liquid distribution component is arranged on the polar plate of each battery module, so that the electrolyte entering the battery module can be uniformly distributed in the battery module through the liquid distribution component, the electrolyte is prevented from generating a dead zone in the battery module, the mass transfer efficiency can be improved, and the performance of the whole single battery is further improved.

Description

Technical Field

[0001] The present disclosure relates to the field of batteries, and in particular, to a multi-module liquid flow battery connected in series. Background Art

[0002] The main components of a flow battery are electrolyte, battery stack, and pump. The active substances of the battery reaction are stored in a tank outside the battery stack. The electrolyte is injected into the battery stack using a pump. When the electrolyte flows parallel to the electrode surface, a chemical reaction occurs. The diaphragm separates the positive and negative electrolytes on the one hand, and allows ions to pass through on the other hand, forming a circuit. The bipolar plate is used to collect electrons.

[0003] Patent CN101127393A discloses a zinc-nickel liquid flow battery, which is composed of a battery stack formed by multiple battery cells connected in series, an electrolyte, a storage tank, a liquid pump and a pipeline, wherein the battery cell is composed of a nickel electrode positive electrode, a negative electrode current collector deposited with zinc and an electrolyte, wherein the electrolyte is an alkaline solution containing zinc, and the two battery cells are connected in series with a bipolar plate. During the charging and discharging process, the electrolyte flows continuously between the storage tank and the battery stack through the pipeline under the push of the liquid pump. During charging, zinc is deposited from the electrolyte onto the negative electrode current collector to become a negative electrode active material, and during discharging, zinc dissolves from the negative electrode current collector into the electrolyte. The liquid flow battery has the advantages of simple manufacturing process, low cost and high cycle life.

[0004] Patent CN101619465B discloses a method for preparing or regulating the capacity of a vanadium battery solution, wherein the electrolysis device used includes an electrolytic cell group, an anolyte storage tank, a catholyte storage tank, a liquid delivery pipeline and a pump, and a forced convection method is adopted to make the anolyte and catholyte stored in the anolyte storage tank and the catholyte storage tank flow through the anode and cathode of the electrolytic cell group respectively, and a voltage is applied between the anode and cathode of the electrolytic cell group to generate direct current that can generate oxygen and reduce vanadium compounds, and after the electrochemical oxidation and reduction reactions are completed, the anolyte and catholyte flowing through the anode and cathode of the electrolytic cell group are returned to the anolyte storage tank and the catholyte storage tank respectively. The electrolysis method is used to prepare an electrolyte solution for an all-vanadium liquid flow battery, and to restore the capacity of an all-vanadium liquid flow battery system offline or online.

[0005] However, the above patents all use pumps to pump electrolyte into the single cells of the battery stack. According to the fluid simulation results, the electrolyte will form a dead zone inside the battery stack where the electrolyte cannot reach. Therefore, the efficiency of the battery stack will decrease. The single-inlet and single-outlet mode of the battery stack increases the flow resistance of the electrolyte. This increases the lift of the delivery pump and the sealing requirements of the battery stack. Summary of the invention

[0006] The purpose of the present invention is to provide a multi-module liquid flow battery connected in series to solve the problems existing in the prior art such as low efficiency of battery stack, electrolyte flow resistance and large delivery pump head.

[0007] In order to achieve the above-mentioned objectives, the present disclosure provides a liquid flow battery with multiple modules connected in series, the liquid flow battery comprising a liquid storage device, a single cell and a liquid infusion pipeline; the single cell is composed of a plurality of battery modules connected in series; the battery module comprises an electrolyte inlet and an electrolyte outlet; the outlet of the liquid storage device is connected to the inlet of the liquid infusion pipeline; the outlet of the liquid infusion pipeline is respectively connected to the electrolyte inlet of each battery module; the electrolyte outlet of each battery module is respectively connected to the inlet of the liquid storage device; a plate with a feed channel and a liquid uniform distribution member is provided inside the battery module; the inlet of the feed channel of the plate extends to the outside of the battery module to form the electrolyte inlet; the liquid uniform distribution member of the plate is arranged on the plate surface opposite to the inlet of the feed channel.

[0008] Optionally, the shape of the liquid uniform distribution member is selected from one or more of a triangular protrusion, a trapezoidal protrusion and an elliptical protrusion, preferably a triangular protrusion.

[0009] Optionally, the battery module includes a diaphragm, an electrode located outside the diaphragm, a polar plate located outside the electrode, and a battery module end plate located outside the polar plate.

[0010] Optionally, a liquid inlet transverse plate is provided between the feed flow channel of the electrode plate and the liquid uniform distribution component; a liquid inlet is provided on the liquid inlet transverse plate; the liquid inlet transverse plate divides the area formed between the electrode and the electrode plate from top to bottom into a liquid confluence area and a liquid distribution area; the liquid confluence area and the liquid distribution area are connected through the liquid inlet of the liquid inlet transverse plate.

[0011] Optionally, the volume ratio of the liquid uniform distribution member to the liquid distribution area is (0.2-0.4):1.

[0012] Optionally, the thickness of the electrode plate is 2 to 8 mm; the thickness of the electrode is 1 to 5 mm.

[0013] Optionally, the ratio of the length of the battery module and the single cell along the direction in which the electrolyte flows in the liquid distribution area is (0.1~0.2):1, the ratio of the length of the battery module and the single cell along the direction in which the electrolyte flows in the liquid confluence area is (0.12~0.18):1, and the ratio of the length of the battery module and the single cell along the direction in which the electrolyte flows in the liquid confluence area is (0.2~0.5):1.

[0014] Optionally, the infusion line is a capillary tube; the length of the capillary tube is 300 to 1000 mm and the diameter is 0.5 to 2 mm.

[0015] Optionally, an electrolyte outlet main channel and an electrolyte outlet branch channel are also provided inside the single battery; the inlet of the electrolyte outlet branch channel is respectively connected to the electrolyte outlet of each battery module; the outlet of the electrolyte outlet branch channel is connected to the inlet of the electrolyte outlet main channel; the outlet of the electrolyte outlet main channel is connected to the inlet of the liquid storage device.

[0016] Optionally, the cross-sections of the electrolyte outlet main channel and the electrolyte outlet branch channel are one or more of rectangular, square and trapezoidal shapes.

[0017] Through the above technical solution, the single battery is divided into multiple battery modules connected in series, and the electrolyte in the liquid storage device enters each battery module through the liquid delivery pipeline at the same time, which can reduce the distance between the liquid inlet and the liquid outlet, thereby reducing the resistance along the electrolyte, and can also reduce the lift of the delivery pump. In addition, a liquid distribution component is provided on the electrode plate of each battery module, which can make the electrolyte entering the battery module be evenly distributed inside the battery module through the liquid distribution component, avoiding the dead zone of the electrolyte inside the battery module, which can improve the mass transfer efficiency, and thus improve the performance of the entire single battery.

[0018] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0020] Figure 1 It is a schematic diagram of a battery module in a multi-module series-connected liquid flow battery disclosed in the present invention.

[0021] Figure 2 It is a schematic diagram of a single cell in a multi-module series-connected liquid flow battery disclosed in the present invention.

[0022] Figure 3 The present invention discloses a schematic diagram of a multi-module flow battery connected in series.

[0023] Description of Reference Numerals

[0024] 1. Battery module; 2. Feed channel; 3. Liquid uniform distribution component; 4. Liquid inlet horizontal plate; 5. Liquid confluence area; 6. Liquid distribution area; 11. Liquid storage device; 12. Single battery; 13. Infusion pipeline. DETAILED DESCRIPTION

[0025] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0026] In the present disclosure, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of a device in normal use. Figure 1 In the drawing direction, "inside" and "outside" refer to the outline of the device. In addition, the term "plurality" means two or more, unless otherwise clearly and specifically defined.

[0027] The present disclosure provides a multi-module liquid flow battery connected in series, the liquid flow battery comprising a liquid storage device 11, a single battery 12 and a liquid infusion line 13; the single battery 12 is composed of a plurality of battery modules 1 connected in series; the battery module 1 comprises an electrolyte inlet and an electrolyte outlet; the outlet of the liquid storage device 11 is connected to the inlet of the liquid infusion line 13 so that the electrolyte in the liquid storage device 11 can enter the liquid infusion line 13; the outlet of the liquid infusion line 13 is connected to the electrolyte inlet of each battery module 1 respectively ... The electrolyte can enter the battery module 1 through the infusion pipeline 13; the electrolyte outlet of each battery module 1 is respectively connected to the inlet of the liquid storage device 11, so that the electrolyte participating in the reaction can return to the liquid storage device 11; a plate with a feed channel 2 and a liquid distribution component 3 is provided inside the battery module 1; the inlet of the feed channel 2 of the plate extends to the outside of the battery module 1 to form the electrolyte inlet; the liquid distribution component 3 of the plate is arranged on the plate surface opposite to the inlet of the feed channel 2.

[0028] Through the above technical solution, the single cell 12 is divided into a plurality of battery modules 1 connected in series, and the electrolyte in the liquid storage device 11 enters each battery module 1 simultaneously through the liquid delivery pipeline 13, which can reduce the distance between the liquid inlet and the liquid outlet, thereby reducing the resistance along the electrolyte, and can also reduce the lift of the delivery pump. In addition, a liquid distribution component is provided on the pole plate of each battery module 1, which can make the electrolyte entering the battery module 1 be evenly distributed inside the battery module 1 through the liquid distribution component, avoiding the dead zone of the electrolyte inside the battery module 1, and can improve the mass transfer efficiency, thereby improving the performance of the entire single cell 12.

[0029] In one embodiment, the battery module 1 includes a diaphragm, electrodes located on both sides of the diaphragm, the electrode plates located outside the electrodes, and the battery module 1 end plates located outside the electrode plates; specifically.

[0030] The diaphragm used in the present disclosure is conventionally selected in the art, and this application does not make any special requirements.

[0031] The materials of the plates and electrodes used in the present disclosure are conventionally selected in the art, and this application does not make any special requirements. In order to match the technical solution of the present disclosure, the thickness of the plates and electrodes is limited. Specifically, the thickness of the plates is 2 to 8 mm; the thickness of the electrodes is 1 to 5 mm.

[0032] In this embodiment, the active components in the electrolyte react with the positive and negative electrodes of the battery respectively, and the electrolyte after the reaction flows through the pipeline into the corresponding electrolyte storage tank. + Ions or other ions enter the opposite electrode through the diaphragm material, connecting the internal circuit of the battery. The diaphragm has the function of isolating electrons and blocking ions and molecules that are not responsible for connecting the circuit. According to the external circuit power supply or load requirements, the battery can work in the charging state or the discharging state, and can switch between the two states. This reciprocating process realizes the continuous operation of the energy storage system.

[0033] like Figure 1 As shown, a liquid inlet transverse plate 4 is provided between the feed channel 2 of the electrode plate and the liquid uniform distribution component 3; a liquid inlet is provided on the liquid inlet transverse plate 4; the liquid inlet transverse plate 4 divides the area formed between the electrode and the electrode plate from top to bottom into a liquid confluence area 5 and a liquid distribution area 6; the liquid confluence area 5 and the liquid distribution area 6 are connected through the liquid inlet of the liquid inlet transverse plate 4.

[0034] In order to evenly distribute the electrolyte in the liquid distribution area 6, a plurality of liquid inlets are arranged on the liquid inlet transverse plate 4, and no liquid inlet is arranged below the outlet of the feed channel 2, so that the electrolyte can be evenly distributed in the liquid confluence area 5 through the liquid inlet transverse plate 4.

[0035] Among them, in order to further improve the uniformity of the distribution of the electrolyte in the liquid confluence area 5, the diameter of the liquid inlet on the liquid inlet horizontal plate 4 is limited. The diameter of the liquid inlet on the liquid inlet horizontal plate 4 is selected according to the horizontal distance between the liquid inlet and the feed channel 2. Specifically, the greater the horizontal distance from the feed channel 2, the larger the diameter.

[0036] The cross-sectional area of ​​the liquid inlet increases by 2 to 8 mm for every 1 mm increase in the horizontal distance between the liquid inlet and the feed channel 2. 2 .

[0037] In this embodiment, if Figure 1As shown, after the electrolyte enters the liquid confluence area 5 through the feed flow channel 2, the liquid moves to both ends under the action of the liquid inlet horizontal plate 4. When the electrolyte moves to both ends, the electrolyte flows into the liquid distribution area 6 through the liquid inlets with gradually larger diameters in sequence, and the flow rate of the electrolyte gradually decreases and the flow rate gradually increases, thereby further improving the uniformity of the electrolyte distribution in the liquid confluence area 5 and further improving the uniformity of the liquid distribution.

[0038] In one embodiment, the shape of the liquid uniform distribution member 3 used in the present disclosure is selected from one or more of a triangular protrusion, a trapezoidal protrusion and an elliptical protrusion, preferably a triangular protrusion.

[0039] The liquid evenly distributing member 3 is evenly distributed in the liquid distribution area 6, and the volume ratio of the liquid evenly distributing member 3 to the liquid distribution area 6 is (0.2-0.4):1, preferably (0.28-0.32):1.

[0040] In this embodiment, by evenly arranging a plurality of liquid distribution components in the liquid distribution area 6, the uniformity of the electrolyte distribution can be further improved. In addition, by arranging liquid distribution components over a large area inside the liquid distribution area 6, dead zones of the electrolyte can be avoided inside the liquid distribution area 6, thereby further improving the electrochemical activity of the battery module 1.

[0041] In one embodiment, in order to further improve the uniformity of electrolyte distribution, the electrode plate feed channel 2 is arranged at the center of the liquid confluence area 5 .

[0042] like Figure 2 As shown, the single cell 12 is composed of a plurality of battery modules 1 arranged in series. In order to reduce the distance between the inlet and outlet, and thereby reduce the resistance along the electrolyte and the lift of the delivery pump, the present application defines the specifications of the battery module 1. Specifically, the ratio of the length of the battery module 1 to the single cell 12 along the direction in which the electrolyte flows in the liquid distribution area 6 is (0.1-0.2):1, the ratio of the length of the electrolyte along the direction in which the electrolyte flows in the liquid confluence area 5 is (0.12-0.18):1, and the ratio of the length of the electrolyte along the direction in which the electrolyte flows in the feed flow channel 2 is (0.2-0.5):1.

[0043] Among them, at least the separator in the single cell 12 is consistent with the size of the single cell 12 to avoid the problem of electrolyte contamination caused by mixing the electrolyte used in the positive electrode and the electrolyte used in the negative electrode.

[0044] The outermost sides of the electrodes of all battery modules 1 are in close contact with the end plates of the single cells 12 .

[0045] Among them, Figure 2In the direction of use, two adjacent battery modules 1 on the same horizontal line are tightly combined, and a certain gap is left between the two adjacent rows of battery modules 1 above and below, and the gap forms an electrolyte outlet branch channel between the diaphragm and the end plate; there is a gap between the rightmost column of battery modules 1 and the side of the segment single cell 12, and the gap forms an electrolyte outlet main channel between the diaphragm and the end plate. In this embodiment, an electrolyte outlet main channel and an electrolyte outlet branch channel are also provided inside the single cell 12; wherein the inlet of the electrolyte outlet branch channel is respectively connected to the electrolyte outlet of each battery module 1, so that the electrolyte in each battery module 1 can enter the electrolyte outlet branch channel; the outlet of the electrolyte outlet branch channel is connected to the inlet of the electrolyte outlet main channel, so that the electrolyte collected through the electrolyte outlet branch channel can enter the electrolyte outlet main channel; the outlet of the electrolyte outlet main channel is connected to the inlet of the liquid storage device 11, so that the electrolyte in the single cell 12 can return to the liquid storage device 11.

[0046] In order to further improve the battery performance, the cross-sections of the electrolyte outlet main channel and the electrolyte outlet branch channel can be one or more of rectangular, square and trapezoidal shapes.

[0047] The battery power of each single battery 12 can be selected according to actual use requirements. Preferably, the battery power of each single battery 12 is 0.15 to 0.3 KW.

[0048] like Figure 3 As shown, the infusion line 13 is a capillary; the length of the capillary is 300 to 1000 mm, preferably 350 to 500 mm, and the diameter is 0.5 to 2 mm, preferably 0.8 to 1 mm. In this embodiment, the present disclosure divides the single cell 12 into 30 to 50 battery modules 1. By setting the same number of capillaries as the number of battery modules 1 and connecting each capillary to each battery module 1, the distance between the inlet and outlet can be reduced, thereby reducing the resistance of the electrolyte along the way, and can also reduce the head of the delivery pump. In addition, by selecting the length and diameter of the capillary, the resistance of the electrolyte along the way can be further shortened, and the head of the delivery pump can also be reduced.

[0049] Wherein, a circulation pump and a flow regulating valve are arranged on the outlet pipeline of the electrolyte outlet main channel.

[0050] In one embodiment, a temperature detection device is further provided in the liquid storage device 11 for detecting the temperature of the electrolyte therein.

[0051] A method for operating a multi-module flow battery in series disclosed herein includes: connecting the positive electrolyte inlet of each battery module 1 in a single cell 12 to the outlet of a positive electrode storage device through a positive electrode infusion pipeline, and connecting the negative electrolyte inlet to the outlet of a negative electrode storage device through a negative electrode infusion pipeline, so that the positive electrolyte and negative electrolyte stored in the positive electrolyte storage tank and the negative electrolyte storage tank, respectively, flow through the positive and negative electrodes of the battery pack through an electrolyte delivery system; connecting the outlet of the electrolyte outlet main channel of the single cell 12 on the positive electrode side to the inlet of the positive electrode storage device, and connecting the outlet of the electrolyte outlet main channel of the single cell 12 on the negative electrode side to the inlet of the negative electrode storage device; so that after the electrolyte completes the electrochemical oxidation and reduction reaction, the positive electrolyte and negative electrolyte flowing through the positive and negative electrodes of the electrolytic cell group return to the positive electrolyte storage tank and the negative electrolyte storage tank, respectively. This process is repeated to achieve continuous operation of the energy storage system.

[0052] In one embodiment, the liquid flow battery disclosed in the present invention includes an end plate and a battery stack, wherein the battery stack is composed of a plurality of single cells 12 connected in series, wherein the electrolyte flow channels of the plurality of single cells 12 can be connected in series or in parallel. In this embodiment, when the electrolyte flow channels of the plurality of single cells 12 are connected in series, the liquid storage device 11 is connected to the electrolyte inlet of the battery module 1 of the outermost single cell 12 through a capillary; the outlet of the electrolyte outlet main channel of the single cell 12 is connected to the electrolyte inlet of the battery module 1 of the next level single cell 12 through a capillary. When the electrolyte flow channels of the plurality of single cells 12 are connected in parallel, the capillary is divided into a capillary main line and a capillary branch line, the outlet of the liquid storage device 11 is connected to the inlet of the capillary main line, and the outlet of the capillary main line is connected to the electrolyte inlet of the battery module 1 of each single cell 12 through a capillary branch line.

[0053] The battery module 1 between two adjacent single cells 12 may be connected via a capillary tube so that the two adjacent single cells 12 are connected.

[0054] A method for measuring the battery efficiency of a multi-module series-connected flow battery disclosed herein comprises:

[0055] S1. After charging the battery system to 100% SOC, the battery system is discharged at rated power until the discharge cut-off condition is reached;

[0056] S2, after charging the battery system at rated power until the charging cut-off condition, discharging the battery system at rated power until the discharging cut-off condition, measuring the energy Ed1 released by the battery stack during the charging and discharging process and the energy Ec1 consumed by the battery stack during the charging and discharging process;

[0057] S3, repeating the operation of step S2 for n times, obtaining the energy Edn released by the battery stack during the n times of charge and discharge and the energy Ecn consumed by the battery stack during the n times of charge and discharge;

[0058] S4. Calculate the battery efficiency η of the battery stack according to formula 1:

[0059]

[0060] Among them, Ed1 is the energy released by the battery stack during the first charge and discharge process, Ed2 is the energy released by the battery stack during the second charge and discharge process, and Edn is the energy released by the battery stack during the nth charge and discharge process; Ec1 is the energy consumed by the battery stack during the first charge and discharge process, Ec2 is the energy consumed by the battery stack during the second charge and discharge process, and Ecn is the energy consumed by the battery stack during the nth charge and discharge process; the units are all watt-hours (W·h).

[0061] Among them, the measurement method of the energy consumed and released during the charging and discharging process of the battery stack is a conventional choice in this field, and this application does not make any special requirements.

[0062] The present disclosure is further described in detail by way of examples. The raw materials used in the examples can all be obtained through commercial sources.

[0063] Example 1

[0064] like Figure 1 , Figure 2 , Figure 3 As shown, the multi-module series flow battery includes: a battery stack with a power of 5KW, 200 capillaries with a length of 40mm and an inner diameter of 1mm, a positive electrode liquid storage device and a negative electrode liquid storage device; wherein the single cell 12 is divided into 50 battery modules 1; the ratio of the length of the battery module 1 to the single cell 12 along the direction of the electrolyte flowing in the liquid distribution area 6 is 0.1:1, the ratio of the length along the direction of the electrolyte flowing in the liquid confluence area 5 is 0.12:1, and the ratio of the length along the direction of the electrolyte flowing in the feed flow channel 2 is 0.2:1. wherein the shape of the liquid uniform distribution member 3 is a triangular protrusion; the volume ratio of the liquid uniform distribution member 3 to the liquid distribution area 6 is 0.3:1.

[0065] The operation method of the multi-module series flow battery includes: connecting the positive electrolyte inlet of each battery module 1 in the single battery 12 with the outlet of the positive electrode storage device through the positive electrode infusion pipeline, and connecting the negative electrolyte inlet with the outlet of the negative electrode storage device through the negative electrode infusion pipeline, so that the positive electrolyte and the negative electrolyte stored in the positive electrolyte storage tank and the negative electrolyte storage tank flow through the positive and negative electrodes of the battery group through the electrolyte delivery system; connecting the outlet of the electrolyte outlet main channel of the single battery 12 on the positive electrode side with the inlet of the positive electrode storage device, and connecting the outlet of the electrolyte outlet main channel of the single battery 12 on the negative electrode side with the inlet of the negative electrode storage device; so that after the electrolyte completes the electrochemical oxidation and reduction reaction, the positive electrolyte and the negative electrolyte flowing through the positive and negative electrodes of the electrolytic cell group return to the positive electrolyte storage tank and the negative electrolyte storage tank respectively. This process is repeated to achieve continuous operation of the energy storage system.

[0066] The operating conditions and related data of the battery are shown in Table 1.

[0067] Example 2

[0068] The multi-module flow battery is the same as that in Example 1, except that the volume ratio of the liquid uniform distribution member 3 to the liquid distribution area 6 is 0.25:1. The operating conditions and related data of the battery are shown in Table 1.

[0069] Example 3

[0070] The multi-module flow battery is the same as in Example 1, except that the power of the battery stack is 10KW. The operating conditions and related data of the battery are shown in Table 1.

[0071] Comparative Example 1

[0072] The multi-module flow battery is the same as in Example 1, except that the power of the battery stack is 5KW, wherein the single cell 12 in the battery stack is not divided into a plurality of battery modules 1 and no liquid distribution member is provided inside the single cell 12. The operating conditions and related data of the battery are shown in Table 1.

[0073] Comparative Example 2

[0074] The multi-module flow battery is the same as the comparative example 1, except that the power of the battery stack is 10KW. The operating conditions and related data of the battery are shown in Table 1.

[0075] Comparative Example 3

[0076] The single cell in this embodiment includes a perfluorosulfonic acid diaphragm, and a positive half-cell and a negative half-cell respectively located on both sides of the perfluorosulfonic acid diaphragm. Among them, the plate of the positive (or negative) half-cell is 10mm thick and made of graphite. The surface in contact with the electrode is a surface with a roughness grade of N7 and an electrode with a thickness of 8mm and a size of 200mm×200mm, and the material is graphite felt. One side of the electrode is engraved with an electrolyte flow channel with a square cross-section of 1mm wide and 1mm deep, with a total area of ​​200mm×200mm; the side engraved with the electrolyte flow channel is in contact with the perfluorosulfonic acid diaphragm, and the other opposite side is embedded in the plate with an embedding depth of 2mm. In addition, polytetrafluoroethylene sealing materials and end plates are placed around the electrode. The single cells connected in series constitute a battery stack, and the battery stack also includes a liquid distributor, and the end plate is placed outside the one-way liquid distributor, and the above components are fastened with bolts through preset holes.

[0077] The operating conditions and related data of the battery are shown in Table 1.

[0078] Table 1 Operating conditions and related data of the batteries in the embodiments and comparative examples

[0079] Ambient temperature Electrolyte temperature rise Run time Battery power Battery efficiency Electrolyte flow rate Example 1 26℃ 3℃ 10 hours 5KW 77.5％ <![CDATA[2m 3 / h]]> Example 2 26℃ 3℃ 10 hours 5KW 77.1％ <![CDATA[2m 3 / h]]> Example 3 26℃ 4℃ 10 hours 10KW 76％ <![CDATA[2m 3 / h]]> Comparative Example 1 26℃ 10℃ 10 hours 5KW 71％ <![CDATA[2m 3 / h]]> Comparative Example 2 26℃ 14℃ 10 hours 10KW 68％ <![CDATA[2m 3 / h]]> Comparative Example 3 26℃ 7℃ 10 hours 5KW 74％ 2m3 / h

[0080] As shown in Table 1, by comparing the data in Examples 1 to 3 and Comparative Examples 1 to 3, it can be seen that dividing a single cell into multiple battery modules connected in series and allowing the electrolyte in the liquid storage device to enter each battery module simultaneously through the liquid infusion pipeline can reduce the distance between the liquid inlet and the liquid outlet, thereby reducing the resistance along the electrolyte and reducing the temperature rise of the electrolyte. In addition, a liquid distribution member is provided on the electrode plate of each battery module, so that the electrolyte entering the battery module can be evenly distributed inside the battery module through the liquid distribution member, avoiding the dead zone of the electrolyte inside the battery module, and improving the mass transfer efficiency, thereby improving the efficiency of the entire system.

[0081] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0082] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0083] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A multi-module flow battery, characterized in that: The liquid flow battery comprises a liquid storage device (11), a single battery (12) and a liquid infusion pipeline (13); The single battery (12) is composed of a plurality of battery modules (1) connected in series; the battery module (1) comprises an electrolyte inlet and an electrolyte outlet; The outlet of the liquid storage device (11) is in communication with the inlet of the liquid infusion line (13); the outlet of the liquid infusion line (13) is in communication with the electrolyte inlet of each battery module (1); the electrolyte outlet of each battery module (1) is in communication with the inlet of the liquid storage device (11); A pole plate with a feed channel (2) and a liquid uniform distribution member (3) is provided inside the battery module (1); the inlet of the feed channel (2) of the pole plate extends to the outside of the battery module (1) to form the electrolyte inlet; the liquid uniform distribution member (3) of the pole plate is arranged on the plate surface opposite to the inlet of the feed channel (2).

2. The flow battery according to claim 1, characterized in that: The shape of the liquid uniform distribution member (3) is selected from one or more of a triangular protrusion, a trapezoidal protrusion and an elliptical protrusion, preferably a triangular protrusion.

3. The liquid flow battery according to claim 1, characterized in that: The battery module (1) comprises a diaphragm, an electrode located outside the diaphragm, the electrode plate located outside the electrode, and an end plate of the battery module (1) located outside the electrode plate.

4. The flow battery according to claim 3, characterized in that: A liquid inlet transverse plate (4) is provided between the feed flow channel (2) of the electrode plate and the liquid uniform distribution member (3); a liquid inlet is provided on the liquid inlet transverse plate (4); The liquid inlet transverse plate (4) divides the area formed between the electrode and the electrode plate from top to bottom into a liquid confluence area (5) and a liquid distribution area (6); The liquid confluence area (5) and the liquid distribution area (6) are connected via the liquid inlet of the liquid inlet transverse plate (4).

5. The flow battery according to claim 4, characterized in that: The volume ratio of the liquid uniform distribution component (3) to the liquid distribution area (6) is (0.2-0.4):

1.

6. The flow battery according to claim 3, characterized in that: The thickness of the polar plate is 2-8 mm; the thickness of the electrode is 1-5 mm.

7. The flow battery according to claim 4, characterized in that: The ratio of the length of the battery module (1) to the length of the single cell (12) along the direction in which the electrolyte flows in the liquid distribution area (6) is (0.1-0.2):1, the ratio of the length of the battery module (1) to the length of the single cell (12) along the direction in which the electrolyte flows in the liquid confluence area (5) is (0.12-0.18):1, and the ratio of the length of the battery module (1) to the length of the single cell (12) along the direction in which the electrolyte flows in the feed channel (2) is (0.2-0.5):

1.

8. The flow battery according to claim 1, characterized in that: The infusion pipeline (13) is a capillary tube; the length of the capillary tube is 300 to 1000 mm, and the diameter is 0.5 to 2 mm.

9. The flow battery according to claim 1, characterized in that: The single cell (12) is also provided with an electrolyte outlet main channel and an electrolyte outlet branch channel; The inlet of the electrolyte outlet branch channel is respectively connected to the electrolyte outlet of each battery module (1); the outlet of the electrolyte outlet branch channel is connected to the inlet of the electrolyte outlet main channel; and the outlet of the electrolyte outlet main channel is connected to the inlet of the liquid storage device (11).

10. The liquid flow battery according to claim 9, characterized in that: The cross-sections of the electrolyte outlet main channel and the electrolyte outlet branch channel are one or more of rectangular, square and trapezoidal shapes.

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