A zinc-based liquid flow battery with movable negative electrode and manufacturing method thereof

Abstract

The present invention relates to the technical field of batteries, and discloses a zinc-based flow battery with a movable negative electrode and a manufacturing method. The zinc-based flow battery with a movable negative electrode comprises a diaphragm, a positive electrode, a positive electrolyte, a positive electrolyte storage tank, a first circulation pump, a negative electrode, a zinc-based negative electrolyte, a second circulation pump and a negative winding assembly. The positive electrode and the negative electrode are respectively arranged on both sides of the diaphragm, and a first cavity for filling the positive electrolyte is provided between the positive electrode and the diaphragm, and a second cavity for filling the zinc-based negative electrolyte is provided between the negative electrode and the diaphragm. The positive electrolyte storage tank and the first cavity are connected by a pipeline to form a connecting loop, and a circulation pump is provided on the pipeline between the positive electrolyte storage tank and the first cavity. The negative electrolyte storage tank and the second cavity are connected by a pipeline to form a connecting loop, and a circulation pump is provided on the pipeline between the negative electrolyte storage tank and the second cavity. The negative winding assembly can drive the negative electrode to move.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a zinc-based liquid flow battery with a movable negative electrode and a manufacturing method thereof. Background Art

[0002] Fossil energy is still the world's main energy source, and the climate change caused by the massive consumption of fossil energy has made humans pay more and more attention to the climate. The international community generally believes that excessive carbon dioxide emissions are the main factor causing climate change. However, renewable energy generation represented by wind and solar energy is discontinuous, which seriously affects the safe and stable operation of smart grids. Large-scale long-term energy storage technology is an effective way to solve this problem. Among them, aqueous flow battery energy storage technology has become one of the preferred technologies for power system energy storage due to its high safety and long cycle life. Zinc-based flow battery with movable negative electrode is one of the three main flow batteries, and others include vanadium flow battery and iron-chromium flow battery. At present, vanadium flow battery has the highest maturity and the fastest commercialization process; other battery systems such as zinc-based flow battery with movable negative electrode are still in the early stages of research and development and commercialization. Compared with other batteries, zinc-based flow battery with movable negative electrode has the advantages of low cost, high energy density, good safety and environmental friendliness, and has good application prospects in the field of large-scale energy storage.

[0003] However, in the cycling process of zinc-based flow batteries with movable negative electrodes, the reactant Zn in the electrolyte 2+ The ions are easily reduced and deposited on the protrusions on the surface of the negative electrode, forming metal zinc dendrites. The continuous growth of zinc dendrites will pierce the diaphragm, eventually causing the battery to short circuit and fail.

[0004] Therefore, there is an urgent need for a zinc-based liquid flow battery with a movable negative electrode and a manufacturing method to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a zinc-based liquid flow battery with a movable negative electrode and a manufacturing method thereof, so as to prevent the zinc metal deposited on the negative electrode from piercing the diaphragm during charging.

[0006] In order to achieve the above-mentioned object, the present invention provides a zinc-based liquid flow battery with a movable negative electrode, characterized in that it includes a diaphragm, a positive electrode, a positive electrolyte, a positive electrolyte storage tank, a first circulation pump, a negative electrode, a zinc-based negative electrolyte, a negative electrolyte storage tank, a second circulation pump and a negative winding assembly;

[0007] The positive electrode and the negative electrode are respectively arranged on both sides of the diaphragm, a first cavity for filling the positive electrolyte is provided between the positive electrode and the diaphragm, a second cavity for filling the zinc-based negative electrolyte is provided between the negative electrode and the diaphragm, the positive electrolyte storage tank is connected to the first cavity through a pipeline to form a communication loop, the first circulation pump is provided on the pipeline between the positive electrolyte storage tank and the first cavity, the negative electrolyte storage tank is connected to the second cavity through a pipeline to form a communication loop, and the second circulation pump is provided on the pipeline between the negative electrolyte storage tank and the second cavity;

[0008] The negative electrode winding assembly is capable of driving the negative electrode to move;

[0009] When the zinc-based liquid flow battery with a movable negative electrode is charged, zinc ions in the zinc-based negative electrode electrolyte are reduced to form zinc metal deposited on the region of the negative electrode opposite to the diaphragm, and the negative electrode winding assembly drives the negative electrode to move toward the first end of the negative electrode, so that the negative electrode with the zinc metal deposited is away from the diaphragm, and a new negative electrode region is transferred to a position opposite to the diaphragm;

[0010] When the zinc-based liquid flow battery with a movable negative electrode is discharged, the negative electrode winding assembly drives the negative electrode to move toward the second end of the negative electrode, so that the area of ​​the negative electrode where the zinc metal is deposited moves to be opposite to the diaphragm, and the zinc metal undergoes an oxidation reaction to generate zinc ions that dissolve in the zinc-based negative electrode electrolyte.

[0011] As an improvement of the above technical solution, it also includes a positive electrode collector and a negative electrode collector, the positive electrode collector is electrically connected to the positive electrode, and the negative electrode collector is electrically connected to the negative electrode.

[0012] As an improvement of the above technical solution, the negative electrode winding assembly includes a first rotating shaft, a second rotating shaft and a driving device, the first rotating shaft and the second rotating shaft are both rotatably arranged on a side of the diaphragm close to the negative electrode, and the rotation axes are parallel to the diaphragm, one end of the negative electrode is wound on the first rotating shaft, and the other end is wound on the second rotating shaft, and the driving device can drive the first rotating shaft to rotate in a first direction, and can drive the second rotating shaft to rotate in a second direction opposite to the first direction;

[0013] When the zinc-based flow battery with a movable negative electrode is charged, the driving device drives the first rotating shaft to rotate along the first direction, so that a part of the first end of the negative electrode is wound around the first rotating shaft, and a part of the second end of the negative electrode is separated from the second rotating shaft;

[0014] When the zinc-based liquid flow battery with a movable negative electrode is discharged, the driving device drives the second rotating shaft to rotate along the second direction, so that a partial area of ​​the second end of the negative electrode is wound around the second rotating shaft, and a partial area of ​​the first end of the negative electrode is separated from the first rotating shaft.

[0015] As an improvement of the above technical solution, it also includes a support component, which is arranged on the side of the diaphragm close to the negative electrode, the first rotating shaft and the second rotating shaft are both arranged on the side of the support component away from the diaphragm, and the negative electrode is wound around the support component.

[0016] As an improvement of the above technical solution, the support assembly includes a third rotating shaft and a fourth rotating shaft arranged at intervals along a third direction, the third direction is parallel to the diaphragm, and the third rotating shaft and the fourth rotating shaft can both rotate around their own axes, and the rotation axes are parallel to the diaphragm.

[0017] As an improvement of the above technical solution, the negative electrode current collector is provided with a strip hole extending along the third direction, and the third rotating shaft and the fourth rotating shaft are both located in the strip hole and are rotatably connected to the negative electrode current collector.

[0018] As an improvement of the above technical solution, it also includes a first cavity and a second cavity, the first cavity and the negative electrode current collecting plate are arranged to form a third cavity, the first rotating shaft and the second rotating shaft are both located in the third cavity, and are both rotatably connected to the first cavity, the second cavity and the negative electrode plate and the diaphragm are arranged to form a second cavity, the third cavity and the first cavity are connected through the strip hole, and the third cavity and the second cavity are both filled with the zinc-based negative electrode electrolyte.

[0019] As an improvement of the above technical solution, the driving device includes:

[0020] A first motor, which is arranged outside the first cavity;

[0021] A first magnetic coupling, wherein a first magnet of the first magnetic coupling is disposed outside the first cavity and is transmission-connected to the first motor, a second magnet of the first magnetic coupling is disposed in the first cavity, and the second magnet of the first magnetic coupling is fixedly connected to the first rotating shaft and is coaxially disposed;

[0022] A second motor, which is arranged outside the first cavity;

[0023] The second magnetic coupling, the first magnet of the second magnetic coupling is arranged outside the first cavity and is connected to the second motor transmission, the second magnet of the second magnetic coupling is arranged in the first cavity, the second magnet of the second magnetic coupling is fixedly connected to the second rotating shaft and is coaxially arranged.

[0024] As an improvement of the above technical solution, the negative electrode is copper foil.

[0025] The present invention also provides a method for charging and discharging a zinc-based liquid flow battery with a movable negative electrode, which is used for manufacturing the zinc-based liquid flow battery with a movable negative electrode as described in any one of the above, comprising:

[0026] S1. preparing the positive electrode electrolyte: weighing a certain amount of iron salt, chromium salt, vanadium salt or cerium salt, and dissolving it in deionized water to form the positive electrode electrolyte;

[0027] S2) preparing the zinc-based negative electrode electrolyte: weighing a certain amount of zinc salt and dissolving it in deionized water to form the zinc-based negative electrode electrolyte;

[0028] S3) assembling the separator, the positive electrode, the positive electrolyte storage tank, the first circulation pump, the negative electrode, the negative electrolyte storage tank, the second circulation pump and the negative electrode winding assembly;

[0029] S4) Injecting the positive electrode electrolyte and the zinc-based negative electrode electrolyte: injecting the prepared positive electrode electrolyte into the positive electrode electrolyte storage tank and the first cavity, and injecting the prepared zinc-based negative electrode electrolyte into the negative electrode electrolyte storage tank and the second cavity.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The zinc-based liquid flow battery with a movable negative electrode of the present invention, when the zinc-based liquid flow battery with a movable negative electrode is charged, the zinc ions in the zinc-based negative electrode electrolyte are reduced to form zinc metal deposited on the area of ​​the negative electrode opposite to the diaphragm, and the negative electrode winding assembly drives the negative electrode to move toward the first end of the negative electrode so that different areas of the negative electrode are opposite to the diaphragm, that is, during the charging process, the area on the negative electrode where zinc metal is deposited is moved away from the diaphragm by the negative electrode winding assembly and no longer opposite to the diaphragm, and the area on the negative electrode where zinc metal is not deposited is moved to the area opposite to the diaphragm, thereby preventing the zinc metal on the negative electrode from growing to the extent that it can pierce the diaphragm, thereby preventing the zinc metal from piercing the diaphragm. When the zinc-based liquid flow battery with a movable negative electrode is discharged, the negative electrode winding assembly drives the negative electrode to move toward the second end of the negative electrode so that the area on the negative electrode where zinc metal is deposited moves to opposite to the diaphragm, and as the discharge proceeds, the zinc metal undergoes an oxidation reaction to become zinc ions again and dissolve in the zinc-based negative electrode electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of a zinc-based liquid flow battery with a movable negative electrode provided by an embodiment of the present invention during charging;

[0033] Figure 2 It is a schematic structural diagram of a zinc-based liquid flow battery with a movable negative electrode provided in an embodiment of the present invention during discharge.

[0034] In the figure:

[0035] 1. Diaphragm; 2. Positive electrode; 3. Negative electrode; 4. First rotating shaft; 5. Second rotating shaft; 6. Third rotating shaft; 7. Fourth rotating shaft; 8. Positive electrolyte storage tank; 9. First circulation pump; 10. Negative electrolyte storage tank; 11. Second circulation pump; 12. Positive electrode cavity; 13. Negative electrode cavity. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0037] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0040] like Figure 1 and Figure 2 As shown, a zinc-based liquid flow battery with a movable negative electrode according to a preferred embodiment of an embodiment of the present invention comprises a diaphragm 1, a positive electrode 2, a positive electrolyte, a positive electrolyte storage tank 8, a first circulation pump 9, a negative electrode 3, a zinc-based negative electrolyte, a negative electrolyte storage tank 10, a second circulation pump 11 and a negative winding assembly.

[0041] The positive electrode 2 and the negative electrode 3 are respectively arranged on both sides of the diaphragm 1, and a first cavity for filling the positive electrode electrolyte is provided between the positive electrode 2 and the diaphragm 1. The positive electrode electrolyte is a neutral solution containing cations, and the cations can be iron ions, chromium ions, vanadium ions or cerium ions, such as 0.1-1 mol / L FeCl3 solution, 0.1-1 mol / L K3Fe(CN)4 solution, 0.1-1 mol / L ferrocene derivative solution, 0.1-1 mol / L CuSO4 solution or 0.1-1 mol / L NiCl2 solution, etc. Specifically, in the present embodiment, the cations are iron ions, that is, the positive electrode electrolyte is an iron salt solution. In this embodiment, the negative electrode 3 is copper foil, and the specific material of the copper foil can be electrolytic copper, phosphor copper, brass or chromium copper, etc. The positive electrode 2 is carbon felt, which is a common positive electrode material for zinc-based liquid flow batteries with movable negative electrodes. The specific arrangement of the carbon felt is common knowledge in the field and will not be repeated here. The diaphragm 1 is a cationic conductive polymer membrane, that is, a cation exchange membrane, and its components can be perfluorosulfonic acid, sulfonated polyetheretherketone, polystyrene or polyethersulfone, etc., or a composite membrane composed of multiple components.

[0042] There is a second cavity between the negative electrode 3 and the diaphragm 1 for filling with a zinc-based negative electrode electrolyte. The zinc-based negative electrode electrolyte is a neutral solution containing zinc ions, that is, the zinc-based negative electrode electrolyte is a zinc salt solution. The zinc ions mentioned here are divalent zinc ions. In the present embodiment, the zinc-based negative electrode electrolyte is a 0.1-1 mol / L ZnSO4 solution.

[0043] The positive electrode electrolyte storage tank 8 is connected to the first cavity by a pipeline to form a communication loop. A first circulation pump 9 is provided on the pipeline between the positive electrode electrolyte storage tank 8 and the first cavity. The positive electrode electrolyte storage tank 8 and the first circulation pump 9 cooperate to circulate the positive electrode electrolyte to the first cavity.

[0044] The negative electrode electrolyte storage tank 10 and the second cavity are connected by a pipeline to form a communication loop. A second circulation pump 11 is provided on the pipeline between the negative electrode electrolyte storage tank 10 and the second cavity. The negative electrode electrolyte storage tank 10 and the second circulation pump 11 cooperate to circulate and supply zinc-based negative electrode electrolyte to the second cavity.

[0045] The negative electrode winding assembly can drive the negative electrode 3 to move. When the zinc-based liquid flow battery with a movable negative electrode is charged, the zinc ions in the zinc-based negative electrode electrolyte are reduced to form zinc metal deposited on the area of ​​the negative electrode 3 opposite to the diaphragm 1, and the negative electrode winding assembly drives the negative electrode 3 to move toward the first end of the negative electrode 3, so that the negative electrode 3 with zinc metal deposited is away from the diaphragm, and the new negative electrode 3 area is transferred to the position opposite to the diaphragm 1. When the zinc-based liquid flow battery with a movable negative electrode is discharged, the negative electrode winding assembly drives the negative electrode 3 to move toward the second end of the negative electrode 3, so that the area of ​​the negative electrode 3 with zinc metal deposited moves to the opposite of the diaphragm 1, and the zinc metal undergoes an oxidation reaction to generate zinc ions dissolved in the zinc-based negative electrode electrolyte.

[0046] The present embodiment provides a zinc-based liquid flow battery with a movable negative electrode. When the zinc-based liquid flow battery with a movable negative electrode is charged, zinc ions in the zinc-based negative electrode electrolyte are reduced to form zinc metal deposited on the area of ​​the negative electrode 3 opposite to the diaphragm 1, and the negative electrode winding assembly drives the negative electrode 3 to move toward the first end of the negative electrode 3 so that different areas of the negative electrode 3 are opposite to the diaphragm 1. That is, during the charging process, the area on which zinc metal is deposited on the negative electrode 3 is moved away from the diaphragm 1 and no longer opposite to the diaphragm 1 by the negative electrode winding assembly, while the area on which zinc metal is not deposited on the negative electrode 3 is moved to the area opposite to the diaphragm 1, thereby preventing the zinc metal on the negative electrode 3 from growing to a degree that can pierce the diaphragm 1, thereby preventing the zinc metal from piercing the diaphragm 1. When the zinc-based liquid flow battery with a movable negative electrode is discharged, the negative electrode winding assembly drives the negative electrode 3 to move toward the second end of the negative electrode 3, so that the area of ​​the negative electrode 3 where zinc metal is deposited moves to be opposite to the diaphragm 1. As the discharge proceeds, the zinc metal undergoes an oxidation reaction and turns back into zinc ions that dissolve in the zinc-based negative electrode electrolyte.

[0047] Furthermore, the zinc-based flow battery with a movable negative electrode provided in this embodiment also includes a positive current collector and a negative current collector, the positive current collector is electrically connected to the positive electrode 2, and the negative current collector is electrically connected to the negative electrode 3. The negative current collector and the positive current collector are used to connect an external power-consuming load to supply power to the outside, and to connect an external power source to charge the zinc-based flow battery with a movable negative electrode. Both the negative current collector plate and the positive current collector plate are carbon steel plates, which not only meet the necessary strength for fixing the various components of the zinc-based flow battery with a movable negative electrode, but also can be anti-corrosive, and are easy to process and assemble the various connection ports required, and are also easy to process into various shapes.

[0048] Further, the negative electrode winding assembly includes a first rotating shaft 4, a second rotating shaft 5 and a driving device. The first rotating shaft 4 and the second rotating shaft 5 are both rotatably arranged on the side of the diaphragm 1 close to the negative electrode 3, and the rotation axis is parallel to the diaphragm 1. One end of the negative electrode 3 is wound on the first rotating shaft 4, and the other end is wound on the second rotating shaft 5. The driving device can drive the first rotating shaft 4 to rotate in a first direction, and can drive the second rotating shaft 5 to rotate in a second direction opposite to the first direction. When the zinc-based liquid flow battery with a movable negative electrode is charged, the driving device drives the first rotating shaft 4 to rotate in the first direction, so that a part of the first end of the negative electrode 3 is wound on the first rotating shaft 4, and a part of the second end of the negative electrode 3 is separated from the second rotating shaft 5, that is, the negative electrode 3 is driven to move toward the first end of the negative electrode 3 by the driving device driving the first rotating shaft 4 to rotate in the first direction. When the zinc-based liquid flow battery with a movable negative electrode is discharging, the driving device drives the second rotating shaft 5 to rotate in the second direction, so that a partial area of ​​the second end of the negative electrode 3 is wound around the second rotating shaft 5, and a partial area of ​​the first end of the negative electrode 3 is separated from the first rotating shaft 4, that is, the driving device drives the second rotating shaft 5 to rotate in the second direction to drive the negative electrode 3 to move toward the second end of the negative electrode 3.

[0049] Furthermore, if Figure 1 and Figure 2 As shown, the zinc-based flow battery with movable negative electrode further comprises a support assembly, which is arranged on the side of the diaphragm 1 close to the negative electrode 3, and the first rotating shaft 4 and the second rotating shaft 5 are arranged on the side of the support assembly away from the diaphragm 1, and the negative electrode 3 is wound on the support assembly. Thus, the area where the negative electrode 3 is opposite to the diaphragm 1 can be close enough to the diaphragm 1 to facilitate charging and discharging, and the first rotating shaft 4 and the second rotating shaft 5 are prevented from being too close to the diaphragm 1 to affect the arrangement of the negative electrode current collector.

[0050] Furthermore, if Figure 1 and Figure 2 As shown, the support assembly includes a third rotating shaft 6 and a fourth rotating shaft 7 arranged at intervals along a third direction, the third direction is parallel to the diaphragm 1, and the third rotating shaft 6 and the fourth rotating shaft 7 can both rotate around their own axes, and the rotation axes are parallel to the diaphragm 1. The rotation of the third rotating shaft 6 and the fourth rotating shaft 7 facilitates the movement of the negative electrode 3 relative to the support assembly.

[0051] Furthermore, the third rotating shaft 6 and the fourth rotating shaft 7 are made of metal, and the negative electrode 3 and the negative electrode collector are electrically connected through the third rotating shaft 6 and the fourth rotating shaft 7. In this embodiment, the negative electrode collector is a metal wire, such as a copper wire, and the negative electrode collector is connected to the third rotating shaft 6 or the fourth rotating shaft 7, and can also be connected to both the third rotating shaft 6 and the fourth rotating shaft 7, so as to achieve electrical connection between the negative electrode 3 and the negative electrode collector. Specifically, the third rotating shaft 6 and the fourth rotating shaft 7 are made of one or more of 304 stainless steel and titanium alloy, and these materials have good corrosion resistance to prevent the third rotating shaft 6 and the fourth rotating shaft 7 from being corroded by the zinc-based negative electrode electrolyte. The connection method between the positive electrode 2 and the positive electrode collector is the same as the prior art, which will not be repeated here.

[0052] Optionally, the zinc-based liquid flow battery with a movable negative electrode further includes a first cavity, a mounting plate and a second cavity. The mounting plate is arranged between the first cavity and the second cavity, the first cavity and the mounting plate are arranged to form a third cavity, the first rotating shaft 4 and the second rotating shaft 5 are located in the third cavity, and are both rotatably connected to the first cavity. The second cavity, the mounting plate and the diaphragm 1 are arranged to form a second cavity. A strip hole extending along a third direction is arranged on the mounting plate, the third cavity and the third cavity are connected through the strip hole, and the third cavity and the second cavity are both filled with zinc-based negative electrode electrolyte. The third rotating shaft 6 and the fourth rotating shaft 7 are both located in the strip hole and are rotatably connected to the mounting plate, so that the mounting plate is close to the area where the negative electrode 3 and the diaphragm 1 are opposite. Both ends of the third rotating shaft 6 and both ends of the fourth rotating shaft 7 are rotatably connected to the mounting plate through bearings. Specifically, two first mounting grooves are respectively arranged on the hole walls on both sides of the extending direction of the strip-shaped hole, and a bearing is installed in each of the four first mounting grooves. The two ends of the third rotating shaft 6 are respectively installed on the bearings on both sides of the strip-shaped hole of the mounting plate. Similarly, the two ends of the fourth rotating shaft 7 are also respectively installed on the bearings on both sides of the strip-shaped hole of the mounting plate. The specific installation method between the rotating shaft and the bearing, and between the bearing and the mounting groove is common knowledge in the field and will not be repeated here. The material of the first cavity, the mounting plate and the second cavity are all one or more of organic glass, 304 stainless steel and titanium alloy. The first rotating shaft 4 and the second rotating shaft 5 are also made of one or more of organic glass, 304 stainless steel and titanium alloy. These materials have good corrosion resistance to prevent the third rotating shaft 6 and the fourth rotating shaft 7 from being corroded by the zinc-based negative electrode electrolyte.

[0053] Further, the driving device includes a first motor, a first magnetic coupling, a second motor and a second magnetic coupling. The first motor is arranged outside the first cavity. The first magnet of the first magnetic coupling is arranged outside the first cavity and is connected to the first motor by transmission, the second magnet of the first magnetic coupling is arranged in the first cavity, the second magnet of the first magnetic coupling is fixedly connected to the first rotating shaft 4 and is coaxially arranged. The second motor is arranged outside the first cavity. The first magnet of the second magnetic coupling is arranged outside the first cavity and is connected to the second motor by transmission, the second magnet of the second magnetic coupling is arranged in the first cavity, the second magnet of the second magnetic coupling is fixedly connected to the second rotating shaft 5 and is coaxially arranged. The power of the first motor is transmitted to the first rotating shaft 4 through the first magnetic coupling, and the power of the second motor is transmitted to the second rotating shaft 5 through the second magnetic coupling. The magnetic coupling is an existing product in this field, and its structure and principle are not repeated here. Specifically, two second mounting grooves are arranged on the inner wall of the first cavity, and two third mounting grooves corresponding to the second mounting grooves are arranged on the outer wall of the first cavity. The second mounting groove is coaxially arranged with the corresponding third mounting groove, and the distance between the bottom of the second mounting groove and the bottom of the corresponding third mounting groove is 1 mm, that is, the thickness of the first cavity in this area is 1 mm. Bearings are arranged in both second mounting grooves, one end of the first rotating shaft 4 and the second rotating shaft 5 are respectively inserted into the second mounting grooves and are rotatably connected to the first cavity through bearings, the second magnet of the first magnetic coupling is arranged in one of the second mounting grooves and is fixedly connected to the first rotating shaft 4, the first magnet of the first magnetic coupling is arranged in the corresponding third mounting groove, the second magnet of the second magnetic coupling is arranged in the other second mounting groove and is fixedly connected to the second rotating shaft 5, and the first magnet of the second magnetic coupling is arranged in the corresponding third mounting groove. In this embodiment, the first motor and the second motor are adjustable speed reduction motors.

[0054] Optionally, the zinc-based liquid flow battery with a movable negative electrode also includes a third cavity, which is surrounded by the diaphragm 1 and the positive plate to form a first cavity, and the first cavity is filled with a positive electrode electrolyte. The materials of the first cavity and the second cavity are one or more of organic glass, 304 stainless steel and titanium alloy. The first cavity, the mounting plate, the second cavity and the third cavity can be a whole, or three or two independent parts, and the specific setting method is selected according to actual needs. Specifically, in this embodiment, the second cavity is an independent part, that is, the positive electrode cavity 12, and the first cavity and the third cavity are a whole, that is, the negative electrode cavity 13.

[0055] Optionally, the zinc-based liquid flow battery with a movable negative electrode provided in this embodiment also includes a rubber sealing pad. A rubber sealing pad can be arranged between each two adjacent parts of the zinc-based liquid flow battery with a movable negative electrode to improve the sealing effect, such as between the diaphragm 1 and the second cavity and between the diaphragm 1 and the third cavity. The material of the rubber sealing pad can be a silicone pad, a nitrile rubber pad or a fluororubber pad, etc.

[0056] Optionally, the zinc-based liquid flow battery with a movable negative electrode further comprises a control system, which is capable of controlling the charging process and the discharging process of the zinc-based liquid flow battery with a movable negative electrode.

[0057] This embodiment also provides a method for assembling a zinc-based flow battery with a movable negative electrode, comprising the following steps:

[0058] S1 prepares the positive electrode electrolyte: weighs a certain amount of iron salt, chromium salt, vanadium salt or cerium salt, and completely dissolves it in deionized water to form a positive electrode electrolyte for standby use.

[0059] S2: preparing zinc salt negative electrode electrolyte: weighing a certain amount of zinc salt, and completely dissolving it in deionized water to form a zinc-based negative electrode electrolyte for standby use.

[0060] S3 assembles the positive electrode cavity 12, the negative electrode cavity 13, the negative electrode winding assembly, the separator 1, the positive electrode 2, the positive electrode electrolyte storage tank 8, the first circulation pump 9, the negative electrode 3, the negative electrode electrolyte storage tank 10, the second circulation pump 11, the positive electrode collector and the negative electrode collector, etc.

[0061] S4 injects positive electrode electrolyte and zinc salt negative electrode electrolyte: connect the pipeline on the positive electrode side, and use a high-pressure water pump to pump the prepared positive electrode electrolyte into the positive electrode side, that is, the positive electrode electrolyte storage tank 8 and the first cavity; inject the prepared zinc-based negative electrode electrolyte into the negative electrode side, that is, the negative electrode electrolyte storage tank 10, the second cavity and the third cavity, and then control the zinc-based liquid flow battery with movable negative electrode to charge and discharge through the control system.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A zinc-based liquid flow battery with a movable negative electrode, characterized in that: It comprises a diaphragm (1), a positive electrode (2), a positive electrolyte, a positive electrolyte storage tank (8), a first circulation pump (9), a negative electrode (3), a zinc-based negative electrolyte, a negative electrolyte storage tank (10), a second circulation pump (11) and a negative electrode winding assembly; The positive electrode (2) and the negative electrode (3) are respectively arranged on both sides of the diaphragm (1); a first cavity for filling the positive electrolyte is provided between the positive electrode (2) and the diaphragm (1); a second cavity for filling the zinc-based negative electrolyte is provided between the negative electrode (3) and the diaphragm (1); the positive electrolyte storage tank (8) and the first cavity are connected via a pipeline to form a communication loop; the first circulation pump (9) is provided on the pipeline between the positive electrolyte storage tank (8) and the first cavity; the negative electrolyte storage tank (10) and the second cavity are connected via a pipeline to form a communication loop; the second circulation pump (11) is provided on the pipeline between the negative electrolyte storage tank (10) and the second cavity; The negative electrode winding assembly is capable of driving the negative electrode (3) to move; When the zinc-based liquid flow battery with a movable negative electrode is charged, zinc ions in the zinc-based negative electrode electrolyte are reduced to form zinc metal which is deposited on the area of ​​the negative electrode (3) opposite to the diaphragm (1), and the negative electrode winding assembly drives the negative electrode (3) to move toward the first end of the negative electrode (3), so that the negative electrode (3) with the zinc metal deposited is away from the diaphragm, and a new negative electrode (3) area is transferred to a position opposite to the diaphragm (1); When the zinc-based liquid flow battery with a movable negative electrode is discharged, the negative electrode winding assembly drives the negative electrode (3) to move toward the second end of the negative electrode (3), so that the area of ​​the negative electrode (3) where the zinc metal is deposited moves to be opposite to the diaphragm (1), and the zinc metal undergoes an oxidation reaction to generate zinc ions that dissolve in the zinc-based negative electrode electrolyte.

2. The zinc-based liquid flow battery with a movable negative electrode according to claim 1, characterized in that: It also includes a positive electrode collector and a negative electrode collector, wherein the positive electrode collector is electrically connected to the positive electrode, and the negative electrode collector is electrically connected to the negative electrode.

3. The zinc-based liquid flow battery with a movable negative electrode according to claim 2, characterized in that: The negative electrode winding assembly comprises a first rotating shaft (4), a second rotating shaft (5) and a driving device, wherein the first rotating shaft (4) and the second rotating shaft (5) are both rotatably arranged on a side of the diaphragm (1) close to the negative electrode (3), and the rotation axes are both parallel to the diaphragm (1), one end of the negative electrode (3) is wound on the first rotating shaft (4), and the other end is wound on the second rotating shaft (5), and the driving device can drive the first rotating shaft (4) to rotate in a first direction, and can drive the second rotating shaft (5) to rotate in a second direction opposite to the first direction; When the zinc-based liquid flow battery with a movable negative electrode is charged, the driving device drives the first rotating shaft (4) to rotate along the first direction, so that a part of the first end of the negative electrode (3) is wound around the first rotating shaft (4), and a part of the second end of the negative electrode (3) is separated from the second rotating shaft (5); When the zinc-based liquid flow battery with a movable negative electrode is discharged, the driving device drives the second rotating shaft (5) to rotate along the second direction, so that a partial area of ​​the second end of the negative electrode (3) is wound around the second rotating shaft (5), and a partial area of ​​the first end of the negative electrode (3) is separated from the first rotating shaft (4).

4. The zinc-based liquid flow battery with a movable negative electrode according to claim 3, characterized in that: It also includes a support assembly, which is arranged on a side of the diaphragm (1) close to the negative electrode (3), the first rotating shaft (4) and the second rotating shaft (5) are both arranged on a side of the support assembly away from the diaphragm (1), and the negative electrode (3) is wound around the support assembly.

5. The zinc-based liquid flow battery with a movable negative electrode according to claim 4, characterized in that: The support assembly comprises a third rotating shaft (6) and a fourth rotating shaft (7) which are arranged at intervals along a third direction, wherein the third direction is parallel to the diaphragm (1), and the third rotating shaft (6) and the fourth rotating shaft (7) are both capable of rotating around their own axes, and the rotation axes are both parallel to the diaphragm (1).

6. The zinc-based liquid flow battery with a movable negative electrode according to claim 5, characterized in that: The negative electrode current collector is provided with a strip-shaped hole extending along the third direction, and the third rotating shaft (6) and the fourth rotating shaft (7) are both located in the strip-shaped hole and are rotationally connected to the negative electrode current collector.

7. The zinc-based liquid flow battery with a movable negative electrode according to claim 6, characterized in that: The invention also comprises a first cavity and a second cavity, wherein the first cavity and the negative electrode current collecting plate are arranged to form a third cavity, the first rotating shaft (4) and the second rotating shaft (5) are both located in the third cavity and are both rotatably connected to the first cavity, the second cavity and the negative electrode plate and the diaphragm (1) are arranged to form a second cavity, the third cavity and the first cavity are connected via the strip-shaped hole, and the third cavity and the second cavity are both filled with the zinc-based negative electrode electrolyte.

8. The zinc-based liquid flow battery with a movable negative electrode according to claim 7, characterized in that: The driving device comprises: A first motor, which is arranged outside the first cavity; A first magnetic coupling, wherein a first magnet of the first magnetic coupling is arranged outside the first cavity and is transmission-connected to the first motor, a second magnet of the first magnetic coupling is arranged in the first cavity, and the second magnet of the first magnetic coupling is fixedly connected to the first rotating shaft (4) and is coaxially arranged; A second motor, which is arranged outside the first cavity; A second magnetic coupling, wherein the first magnet of the second magnetic coupling is arranged outside the first cavity and is transmission-connected to the second motor, the second magnet of the second magnetic coupling is arranged inside the first cavity, and the second magnet of the second magnetic coupling is fixedly connected to the second rotating shaft (5) and is coaxially arranged.

9. The zinc-based liquid flow battery with a movable negative electrode according to any one of claims 1 to 8, characterized in that: The negative electrode (3) is copper foil.

10. A method for manufacturing a zinc-based liquid flow battery with a movable negative electrode, characterized in that: The method for manufacturing a zinc-based liquid flow battery with a movable negative electrode according to any one of claims 1 to 9 comprises: S1. preparing the positive electrode electrolyte: weighing a certain amount of iron salt, chromium salt, vanadium salt or cerium salt, and dissolving it in deionized water to form the positive electrode electrolyte; S2) preparing the zinc-based negative electrode electrolyte: weighing a certain amount of zinc salt and dissolving it in deionized water to form the zinc-based negative electrode electrolyte; S3) assembling the separator (1), the positive electrode (2), the positive electrolyte storage tank (8), the first circulation pump (9), the negative electrode (3), the negative electrolyte storage tank (10), the second circulation pump (11) and the negative electrode winding assembly; S4) injecting the positive electrode electrolyte and the zinc-based negative electrode electrolyte: injecting the prepared positive electrode electrolyte into the positive electrode electrolyte storage tank (8) and the first cavity, and injecting the prepared zinc-based negative electrode electrolyte into the negative electrode electrolyte storage tank (10) and the second cavity.

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