A vanadium redox flow battery energy storage device

Abstract

The utility model discloses a kind of all-vanadium redox flow battery energy storage equipment, and it relates to the application field of storage battery.A kind of all-vanadium redox flow battery energy storage equipment, comprising: electrolyte storage tank, electric pile and load;Electric pile includes ion exchange membrane, composite electrode, electrode frame, current collector plate and battery end plate;Ion exchange membrane is set to electric pile center, composite electrode, electrode frame, current collector plate, battery end plate are all provided with two groups, and respectively symmetrically set to the two sides of ion exchange membrane;Composite electrode, electrode frame, current collector plate, battery end plate are sequentially set to the two sides of ion exchange membrane;Electrolyte storage tank is provided with two, and all be connected with electric pile by battery end plate;The two ends of load are connected current collector plate by lead wire.The all-vanadium redox flow battery energy storage equipment provided in the utility model embodiment, by setting composite electrode, can further reduce contact resistance, improve battery energy conversion efficiency.

Description

Technical Field

[0001] This utility model relates to the field of energy storage battery applications, and in particular to an all-vanadium redox flow battery energy storage device. Background Technology

[0002] Compared to short-term energy storage, long-term energy storage is more effective in reducing grid regulation pressure and improving energy utilization efficiency, hence the increasing demand for long-term energy storage. Vanadium redox flow battery long-term energy storage technology, due to its safety, environmental friendliness, and long lifespan, is suitable for large-scale energy storage applications in power generation and transmission. As an infrastructure of the power system, it provides flexible and efficient regulation capabilities. The energy storage medium is an aqueous solution, operating at normal temperature and pressure, eliminating the risk of explosion or combustion. It has an expected lifespan of 25 years, high capacity utilization, environmental friendliness, high residual value, and recyclable electrolyte.

[0003] In a vanadium redox flow battery stack, multiple individual cells are stacked layer by layer under the compaction force of the stack. The electrodes of the individual cells and the bipolar plates come into direct contact, generating contact resistance. Although low contact resistance bipolar plates can effectively reduce the contact resistance between the electrodes and the bipolar plates, the reduction is limited. Utility Model Content

[0004] The purpose of this utility model embodiment is to provide a vanadium redox flow battery energy storage device, which can further reduce contact resistance and improve battery energy conversion efficiency by setting composite electrodes.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: This utility model provides a vanadium redox flow battery energy storage device, including: an electrolyte storage tank, a battery stack, and a load; The fuel cell stack includes an ion exchange membrane, a composite electrode, an electrode frame, a current collector, and a battery end plate. The ion exchange membrane is disposed at the center of the fuel cell stack. The composite electrode, the electrode frame, the current collector, and the battery end plate are each provided in two sets and are symmetrically arranged on both sides of the ion exchange membrane. The composite electrode, the electrode frame, the current collector, and the battery end plate are sequentially arranged on both sides of the ion exchange membrane. Two electrolyte storage tanks are provided, and both are connected to the battery stack through the battery end plate; The two ends of the load are connected to the collector plate via leads.

[0006] In some embodiments, the composite electrode comprises a flexible graphite plate, a conductive adhesive layer, and a graphite felt electrode stacked sequentially.

[0007] In some embodiments, it further includes: a circulation pump; The electrolyte storage tank and the fuel cell stack are connected by a circulation pipe, and the circulation pump is installed on the circulation pipe.

[0008] In some embodiments, it further includes: a control valve; The control valve is located on the circulation pipe.

[0009] In some embodiments, the electrolyte in the electrolyte storage tank is a mixed solution of hydrochloric acid, sulfuric acid, and V2O5.

[0010] In some embodiments, the ion exchange membrane is a fluorinated membrane.

[0011] In some embodiments, a pressure relief valve is provided on the outside of each electrolyte storage tank.

[0012] This invention provides a vanadium redox flow battery energy storage device that integrates bipolar plates and electrodes into a single unit by using a composite electrode. This effectively reduces the contact resistance between the bipolar plates and electrodes, improves the overall charge-discharge performance of the battery, increases the battery energy conversion efficiency, and saves time and effort in stack assembly. Furthermore, this composite electrode is lighter and less expensive. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual process of the method, etc. involved in the embodiments of this disclosure.

[0014] Figure 1 This is a schematic diagram of the structural state of an all-vanadium redox flow battery energy storage device according to some embodiments of this disclosure; Figure 2 This is a schematic diagram of the structural state of a composite electrode according to some embodiments of the present disclosure. Detailed Implementation

[0015] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0016] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0017] This utility model embodiment provides an all-vanadium redox flow battery energy storage device, such as... Figure 1-2 As shown, it includes: electrolyte storage tank 1, fuel cell stack 2 and load 3.

[0018] In some embodiments, the fuel cell stack 2 includes an ion exchange membrane 21, a composite electrode 22, an electrode frame 23, a current collector 24, and a battery end plate 25.

[0019] In some embodiments, the ion exchange membrane 21 is disposed at the center of the fuel cell stack 2. Two sets of composite electrodes 22, electrode frames 23, current collectors 24, and battery end plates 25 are each provided, symmetrically arranged on both sides of the ion exchange membrane 21. The composite electrodes 22, electrode frames 23, current collectors 24, and battery end plates 25 are sequentially arranged on both sides of the ion exchange membrane 21. That is, the composite electrodes 22, electrode frames 23, current collectors 24, and battery end plates 25 are sequentially arranged on both sides of the ion exchange membrane 21 along a direction away from the ion exchange membrane 21.

[0020] The electrode frame 23 is used to fix the composite electrode 22; the current collector 24 is used to collect current, distribute the reactive material evenly on the electrode surface, and separate the anode active material and the cathode active material; the battery end plate 25 is used to assemble the current collector 24.

[0021] In some embodiments, two electrolyte storage tanks 1 are provided, and both are connected to the battery stack 2 via battery end plates 25.

[0022] For example, the two electrolyte storage tanks 1 are respectively an anode electrolyte storage tank 1 and a cathode electrolyte storage tank 1. The anode electrolyte storage tank 1 is used to store the anode electrolyte, and the cathode electrolyte storage tank 1 is used to store the cathode electrolyte.

[0023] For example, the composite electrode 22 is divided into a positive composite electrode and a negative composite electrode, and the positive composite electrode and the negative composite electrode are respectively equipped with V 3+ / V 2+ and V 5+ / V 4+As the charging medium, the positive and negative vanadium electrolytes are separated by an ion exchange membrane 21 to prevent internal short circuits in the vanadium redox flow battery. During charging and discharging, the cathode and anode electrolytes flow through the surfaces of the positive and negative composite electrodes respectively, resulting in electrochemical reactions. The battery can operate within a temperature range of 5–60°C.

[0024] The battery reaction is as follows: Positive electrode: VO 2+ +2H + +e→VO 2+ +H₂O E₀=+1.00V Negative electrode: V 3+ +e→V 2+ E0 = -0.26V Overall battery reaction: VO 2+ +V 2+ +2H + →VO 2+ +V 3+ +H₂O E₀=1.26V In some embodiments, the two ends of the load 3 are connected to the current collector 24 via leads.

[0025] This invention provides a vanadium redox flow battery energy storage device that integrates bipolar plates and electrodes into a single unit by using a composite electrode. This effectively reduces the contact resistance between the bipolar plates and electrodes, improves the overall charge-discharge performance of the battery, increases the battery energy conversion efficiency, and saves time and effort in stack assembly. Furthermore, this composite electrode is lighter and less expensive.

[0026] In some embodiments, the composite electrode 22 includes a flexible graphite plate 221, a conductive adhesive layer 222, and a graphite felt electrode 223 stacked sequentially.

[0027] For example, the conductive adhesive layer 222 is made of thermoplastic phenolic resin, carbon black and graphite powder. The conductive adhesive layer 222 is coated on the surface of the flexible graphite plate 221, and then the graphite felt electrode 223 is thermally bonded to the conductive adhesive layer 222 to form a composite electrode 22.

[0028] In some embodiments, the vanadium redox flow battery energy storage device further includes: a circulation pump 4, wherein the electrolyte storage tank 1 and the stack 2 are connected by a circulation pipe 5, and the circulation pump 4 is disposed on the circulation pipe 5.

[0029] The electrolyte storage tank 1, the circulation pipe 5, and the battery stack 2 constitute the pathway for electrolyte circulation, enabling the redox reaction of the vanadium redox flow battery energy storage device.

[0030] The circulating pump 4 is used to extract electrolyte from the electrolyte storage tank 1, drive the electrolyte to circulate between the circulating pipe 5 and the stack 2, and complete the charging or discharging process in the stack 2.

[0031] In some embodiments, the vanadium redox flow battery energy storage device further includes a control valve (not shown in the figure), which is disposed on the circulation pipe 5. The control valve is used to control the flow rate of the circulation pump 4.

[0032] In some embodiments, the electrolyte in the electrolyte storage tank 1 is a mixed solution of hydrochloric acid, sulfuric acid, and V₂O₅. Based on the original sulfuric acid aqueous solution, hydrochloric acid and sulfuric acid are mixed to increase saturation, while the corrosive vanadium ions are discarded. V₂O₅ can completely replace the role of vanadium ions, and can also improve conductivity and reduce corrosion.

[0033] In some embodiments, the ion exchange membrane 21 is a fluorinated membrane.

[0034] The fluorine-coated membrane is formed by coating a layer of fluorine onto the outer layer of the ion exchange membrane 21. This reduces the amount of fluorine used, reduces environmental pollution, lowers corrosion resistance, and reduces electrolyte leakage.

[0035] In some embodiments, a pressure relief valve (not shown in the figure) is provided on the outside of the electrolyte storage tank 1.

[0036] The pressure relief valve is located on the top and bottom of the side of the electrolyte storage tank 1. It is shaped like a screw. In actual use, if the pressure in the electrolyte storage tank 1 is too high, the pressure can be released through the pressure relief valve to ensure safety.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A vanadium redox flow battery energy storage device, characterized in that: include: Electrolyte storage tank, fuel cell stack, and load; The fuel cell stack includes an ion exchange membrane, a composite electrode, an electrode frame, a current collector, and a battery end plate. The ion exchange membrane is disposed at the center of the fuel cell stack. The composite electrode, the electrode frame, the current collector, and the battery end plate are each provided in two sets and are symmetrically arranged on both sides of the ion exchange membrane. The composite electrode, the electrode frame, the current collector, and the battery end plate are sequentially arranged on both sides of the ion exchange membrane. Two electrolyte storage tanks are provided, and both are connected to the battery stack through the battery end plate; The two ends of the load are connected to the current collector via leads.

2. The all-vanadium redox flow battery energy storage device as described in claim 1, characterized in that, The composite electrode comprises a flexible graphite plate, a conductive adhesive layer, and a graphite felt electrode stacked in sequence.

3. The all-vanadium redox flow battery energy storage device as described in claim 1, characterized in that, Also includes: Circulating pump; The electrolyte storage tank and the fuel cell stack are connected by a circulation pipe, and the circulation pump is installed on the circulation pipe.

4. The all-vanadium redox flow battery energy storage device as described in claim 3, characterized in that, Also includes: Control valve; The control valve is located on the circulation pipe.

5. The all-vanadium redox flow battery energy storage device as described in claim 1, characterized in that, The ion exchange membrane is a fluorinated membrane.

6. The all-vanadium redox flow battery energy storage device as described in claim 1, characterized in that, Each electrolyte storage tank is equipped with a pressure relief valve on its outer side.

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