Active positive pressure oxygen supply system for metal-air battery stack

Abstract

The present invention discloses an active positive pressure oxygen supply system for a metal-air battery stack. A ventilation plate is provided on the outer side of the positive electrode of each battery cell in the stack. The ventilation plate is provided with ventilation windows exposing the positive electrodes, and a plurality of ventilation grooves are provided on the outer surface of the ventilation plate. At least one end of all the ventilation grooves communicates with the ventilation windows; an air inlet and an air outlet communicating with the ventilation grooves are provided on the monomer frame. After the battery cells are stacked and spliced, the air inlets and the air outlets between adjacent battery cells are butt-jointed in pairs, and a continuous air inlet channel and an air outlet channel are formed in the entire stack. A plurality of air flow channels connecting the air inlet channel and the air outlet channel are formed between adjacent battery positive electrodes through the ventilation windows and the ventilation grooves on the ventilation plate. Among them, the air inlet channel is connected to a gas delivery device, and the air outlet channel can be connected to a gas recovery device. The present invention solves the problems such as uneven circulation supply of internal air among multiple battery cells in a metal-air battery stack, and has a simple and compact structure.

Description

Technical Field

[0001] The present invention relates to the technical field of metal-air batteries, and particularly to an active positive pressure oxygen supply system for a metal-air battery stack. Background Art

[0002] A metal-air battery single cell is a chemical power source that uses oxygen in the air as the positive electrode active material, a metal as the negative electrode active material, and a conductive solution as the electrolyte, and generates electrical energy through a discharge reaction under the catalysis of a positive electrode catalyst.

[0003] The outermost layer of the positive electrode material used in a metal-air battery is a waterproof and breathable layer, which has breathability, allowing outside air to enter the positive electrode while the electrolyte inside the reaction cavity does not leak out through the positive electrode. To ensure the continuous and stable discharge reaction of the battery, air needs to be continuously supplied to the positive electrode. Currently, the air supply methods for metal-air batteries are: 1. The natural flow generated by the negative pressure state formed after the positive electrode consumes oxygen in the air; 2. The supply is achieved by using multiple fans on the side of the stack to intake air. The disadvantages of these two non-uniform air intake methods are: (1) The heat dissipation of the positive electrodes of each battery single cell is inconsistent; (2) The consumption of the negative electrodes of each battery single cell is inconsistent, and the consumption of the battery single cell with good ventilation exceeds that of the battery single cell with poor ventilation, resulting in uneven discharge reaction; (3) The volume increases and the energy consumption increases. Summary of the Invention

[0004] Aiming at the defects in the prior art, the present invention provides an active positive pressure oxygen supply system for a metal-air battery stack to solve the problems of low internal air circulation supply efficiency, uneven air intake, complex structure, and positive electrode heat dissipation among multiple battery single cells in the existing stack.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] An active positive pressure oxygen supply system for a metal-air battery stack, the stack is formed by cascading and stacking at least two metal-air battery single cells, the battery single cell includes a single cell frame, positive electrodes symmetrically arranged on both sides of the single cell frame, and a negative electrode inserted into the single cell frame, and the active positive pressure oxygen supply system of the stack includes:

[0007] A ventilation plate arranged outside the positive electrode of the battery single cell, a ventilation window exposing the positive electrode is provided on the ventilation plate, and a plurality of ventilation grooves are provided on the outer surface of the ventilation plate, and at least one end of all the ventilation grooves is communicated with the ventilation window;

[0008] An air inlet and an air outlet communicating with the ventilation groove are arranged through the monomer frame. After the battery monomers are stacked and spliced, the air inlets and the air outlets between adjacent monomer frames are docked in pairs to form an air inlet channel and an air outlet channel for the entire stack. A plurality of air flow channels communicating the air inlet channel and the air outlet channel are formed between the positive electrodes of adjacent battery monomers through the ventilation windows and ventilation grooves on the ventilation plate. Among them, the air inlet channel is connected to a gas delivery device with a gas purification function, and the air outlet channel is connected to a gas recovery device.

[0009] Furthermore, the ventilation windows on the ventilation plate are located within the projection range of the internal discharge reaction area of the battery monomer on the positive electrode.

[0010] Furthermore, partition ribs are arranged in the ventilation windows. The partition ribs divide the ventilation windows into multiple ventilation window units. Ventilation grooves are also arranged on the partition ribs, and adjacent two ventilation window units are communicated through the ventilation grooves on the partition ribs.

[0011] Furthermore, the ventilation grooves are arranged along the length direction and the width direction of the ventilation plate.

[0012] Furthermore, both the air inlet and the air outlet are arranged through the monomer frame along the stacking direction.

[0013] Furthermore, the air inlet is arranged at the bottom of the monomer frame, and there are two air outlets which are symmetrically arranged on both sides of the top of the monomer frame.

[0014] Furthermore, a diversion groove for respectively conducting the ventilation groove on the ventilation plate to the air inlet and the air outlet is arranged on the outer surface of the monomer frame. One of the diversion grooves is arranged between the air inlet and the bottom edge of the ventilation plate; the other is horizontally arranged above the top edge of the ventilation plate and both ends are connected to the air outlet.

[0015] Furthermore, the ventilation groove has a semi-circular cross-section, an elliptical cross-section or a polygonal cross-section.

[0016] The beneficial effects of the present invention are reflected in:

[0017] In the battery cell of the present invention, the vent plate is a component in contact with the positive electrode, and is overlapped with the vent plate on the adjacent battery cell to form a vent component for supplying air to the positive electrode. Ventilation windows and vent grooves are arranged on the vent plate, and the air intake channel and exhaust channel formed by the air intake port and the exhaust port on the battery cell after being overlapped are formed to form an air flow channel connecting the battery stacks. The air enters the two sides of the battery cell from the internal pipe of the single body frame through the air conveying equipment such as a blower, and the air is passed through the air flow channel formed by the overlap of the vent plates of the adjacent battery cells to provide the positive electrode of the battery with oxygen required for the reaction. The air is discharged from the two sides of the vent groove of the vent plate or from the exhaust ports on the upper sides to realize air circulation between multiple battery cells and improve the efficiency of the air supply required for the metal air battery reaction. If the vent grooves on both sides are closed, only the exhaust ports on the upper sides are used for exhaust or when the oxygen cylinder is used for gas supply, the exhaust gas can be collected and recycled, so that the battery stack can be used in a closed environment.

[0018] In summary, the present invention designs an active positive pressure oxygen supply circulation system structure, which solves the problem of circulating air between multiple battery cells in the battery stack. The air flow channel is combined with the positive electrode fixed structure, which has a simple and compact structure and uniform air intake, reducing the volume of the battery stack after assembly. The air intake channel actively provides flowing circulating air through an independent pipeline, and the required air supply equipment consumes very little energy. The actively positive pressure circulating air not only provides the positive electrode with sufficient oxygen required for the discharge reaction, but also takes away the heat from the surface of the positive electrode, thereby improving the cooling and heat dissipation problem of the positive electrode and increasing the service life of the positive electrode. It can also be connected to an oxygen cylinder for operation under low oxygen or anaerobic conditions, thereby increasing the scope of application of the metal air battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0020] Figure 1 A schematic diagram of a stack structure of multiple metal-air battery cells in an embodiment;

[0021] Figure 2 Schematic diagram of the metal-air battery monomer structure in the embodiment;

[0022] Figure 3 It is a schematic diagram of the exploded installation of the positive electrode of the metal-air battery in the embodiment;

[0023] Figure 4 Schematic diagram of a monomer frame structure in an embodiment;

[0024] Figure 5 Schematic diagram of the ventilation plate structure in the embodiment;

[0025] Figure 6 Side view of the ventilation plate in the embodiment;

[0026] Figure 7 Schematic diagram of the air flow route on the metal-air battery monomer in the embodiment.

[0027] Among them, 1 - monomer frame, 100 - reaction window, 107 - positive electrode sealing groove, 121 - air inlet, 122 - exhaust port, 123 - flow guiding groove, 131 - fixing through hole;

[0028] 2 - positive electrode, 200 - positive electrode lead copper sheet, 21 - positive electrode sealing ring, 22 - ventilation plate, 221 - ventilation window, 222 - ventilation groove, 223 - ventilation plate positioning hole, 23 - partition rib;

[0029] 3 - negative electrode, 300 - negative electrode lead copper sheet. Specific implementation manner

[0030] The embodiments of the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0031] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0032] As Figure 1 shown, the stack shown in the figure is assembled by stacking a number of metal-air battery monomers in a cascade connection manner. During the cascade stacking and assembly process of a number of battery monomers, an air inlet channel, an exhaust channel of the active positive pressure oxygen supply system of the stack, and an air flow channel between each battery monomer are formed between adjacent battery monomers. The outermost air inlet 121 is connected to a gas delivery device to supply air to each metal-air battery monomer of the stack, and the exhaust port 122 realizes the discharge and collection of the air flow, realizing the free circulation of air inside and outside the stack.

[0033] Specifically as Figures 2 - 4As shown in the figure, the metal-air battery cell in this embodiment includes a cell frame 1, a positive electrode 2, and a negative electrode 3. A reaction cavity is provided inside the cell frame 1. Reaction windows 100 are respectively arranged at positions corresponding to the two side surfaces of the cell frame 1. The negative electrode 3 is fixedly inserted inside the reaction cavity. The positive electrode 2 is pressed and fixed on the laminated side surface of the cell frame 1 through a ventilation plate 22, covering and sealing the reaction window 100 provided on this side surface and communicating with the reaction cavity, forming a channel for electrolyte circulation in parallel with the negative electrode 3 inside the reaction cavity. The ventilation plate 22 is attached to the outside of the positive electrode 2, and the positive electrode 2 is pressed and assembled on the side surface of the cell frame 1 through the ventilation plate 22, covering and closing the reaction window 100. A positive electrode sealing ring 21 is assembled in a circle between the positive electrode 2 and the cell frame 1 around the periphery of the reaction window 100. The cell frame 1 is provided with a positive electrode sealing groove 107 for embedding the positive electrode sealing ring around the periphery of the reaction window 100, realizing the sealing of the electrolyte inside the reaction cavity at the reaction window 100. The positive electrode 2 can achieve the sealing of the electrolyte, and at the same time, air can enter the positive electrode of the reaction window 100 to provide oxygen for the discharge reaction inside the reaction cavity. The cell frame 1 is respectively provided with a positive electrode lead copper sheet 200 and a negative electrode lead copper sheet 300 for leading out the wiring of the positive electrode 2 and the negative electrode 3. The purpose of this embodiment is to specifically illustrate the air supply method of the battery positive electrode. The positive electrode and negative electrode of the metal-air battery are both conventional technologies in this field, and this embodiment will not elaborate on the positive electrode material, negative electrode material, and the power generation principle of the metal-air battery here.

[0034] With reference to Figure 5 and Figure 6 , after the positive electrode 2 and the ventilation plate 22 are assembled and fixed, the catalytic layer on the inner side surface of the positive electrode 2 contacts the internal discharge reaction area of the cell frame 1. The ventilation plate 22 is provided with a ventilation window 221 exposing the positive electrode 2. A plurality of ventilation grooves 222 are provided on the outer surface of the ventilation plate 22, and at least one end of all the ventilation grooves 222 communicates with the ventilation window. A circle of ventilation plate positioning holes 223 is provided on the outside of the ventilation plate 22. The ventilation plate 22 is fixed to the cell frame 1 through the ventilation plate positioning holes 223 to realize the pressing and assembly of the positive electrode 2.

[0035] The inner surface of the ventilation plate 22 in close contact with the positive electrode 2 is a smooth plane to ensure the flattening of the surface of the positive electrode 2. The ventilation window 221 on the ventilation plate 22 is located within the projection range of the internal discharge reaction area of the battery on the positive electrode 2. In order to avoid the excessive vacancy area of the ventilation window 221 causing the positive electrode to bulge and deform outward, a partition rib 23 is provided in the ventilation window 221. The partition rib 23 divides the ventilation window 221 into multiple ventilation window units. The partition rib 23 is also provided with ventilation grooves 222, and adjacent two ventilation window units are connected through the ventilation grooves 222 on the partition rib 23.

[0036] The ventilation grooves 222 arranged on the ventilation plate 22 in the figure of this embodiment are semicircular grooves or grooves with elliptical or polygonal cross-sections, and the ventilation grooves 222 are arranged along the length direction and the width direction of the ventilation plate 22, that is, the ventilation grooves 222 arranged along the width direction are arranged between the ventilation window 221 and the length side of the ventilation plate 22, and the ventilation grooves 222 arranged along the length direction are arranged between the ventilation window 221 and the width side of the ventilation plate 22, and the ventilation grooves are all arranged through the side edges of the ventilation plate and the side edges of the ventilation windows, so that all the ventilation grooves 222 are connected to the ventilation windows at one end and extend to the end face of the ventilation plate 22 at the other end. In a battery stack with multiple battery cells cascaded and stacked, the cell frames of adjacent battery cells are pressed and contacted through the ventilation plate 22, and the corresponding ventilation grooves 222 and ventilation windows 221 on the ventilation plate 22 form an air flow channel connecting the positive electrode of the battery and the outside of the battery.

[0037] See again Figure 4 An air inlet 121 and an exhaust port 122 are also provided on the monomer frame 1, and the air inlet 121 and the exhaust port 122 are respectively connected to the ventilation groove 222 on the ventilation plate 22 assembled on the monomer frame 1. The air inlets 121 and the exhaust ports 122 of the battery main body 1 of adjacent monomers in the battery stack are connected one by one after the battery monomers are cascaded, overlapped and spliced, so as to form a continuous air inlet channel and exhaust channel inside the battery stack. The air inlet channel and the exhaust channel are independently separated and respectively connected to the air flow channel formed by the ventilation windows and the ventilation grooves between the ventilation plates 22 between adjacent monomers, so as to form an air supply channel network inside the entire battery stack. The air inlet of the outermost monomer is connected to the gas conveying equipment, such as an air pump, through the pipeline, and the air flow is conveyed to the air flow channel between each battery monomer through the air inlet channel, and then discharged and collected through the exhaust channel, so as to realize the free flow of air inside the battery stack and improve the utilization efficiency of the oxygen required by the positive electrode of the battery; improve the cooling and heat dissipation problem of the positive electrode and increase the service life of the positive electrode.

[0038] See also Figure 4 and Figure 7 In this embodiment, the air inlet 121 and the exhaust port 122 are respectively located at the upper and lower parts of the battery cell frame 1, wherein the air inlet 121 is located on the cell frame 1 below the vent plate 22, and the exhaust port 122 is located on the cell frame 1 above the vent plate 22. Since the vent plate 22 only covers the area where the positive electrode is located, in this embodiment, a guide groove 123 is provided on the outer surface of the cell frame between the air inlet 121 and the bottom edge of the vent plate 22 and between the exhaust port 122 and the top edge of the vent plate 22, so as to connect the vent groove on the vent plate 22 with the air inlet 121 and the exhaust port 122 respectively. The air flow entering from the air inlet 121 is as follows: Figure 7As shown by the arrows in the figure, they enter into the ventilation grooves 222 on the ventilation plate 22 respectively through the diversion grooves 123 at the bottom, and pass through the ventilation windows 221 along the ventilation grooves 222 to enter the positive electrode 2, ensuring the continuous supply of oxygen required for the discharge reaction of the positive electrode 2. Part of the flowing air flow is directly discharged from the fuel cell stack through the ventilation grooves 222 on both sides of the ventilation plate 22, or enters the exhaust port 122 through the ventilation grooves 222 on the upper part of the ventilation plate 22 through the upper diversion grooves 123 when the ventilation grooves 222 on both sides are closed, and the excess oxygen is recovered through the exhaust passage.

[0039] The fuel cell stack is composed of multiple battery monomers cascaded and stacked. Along the stacking direction on the monomer frame 1 of the battery monomer, there are fixed through holes 131 for cascading and connecting the battery monomers in series. At the same time, the air inlet 121 and the exhaust port 122 on the monomer frame 1 are both arranged through the monomer frame 1 along the stacking direction of the battery monomer. After being cascaded and stacked into a fuel cell stack, the fixed through holes 131, the air inlet 121 and the exhaust port 122 are coaxially docked to form a complete channel. Among them, the fixed through holes 131 position and lock the fuel cell stack through guide rods and connectors. The air inlet 121 and the exhaust port 122 form an air supply intake channel and an exhaust channel. Between the positive electrodes 2 of adjacent battery monomers, several air flow channels connecting the intake channel and the exhaust channel are formed through the ventilation windows 221 and the ventilation grooves 222 on the ventilation plate 22.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and the description of the present invention.

Claims

1. An active positive pressure oxygen supply system for a metal-air battery stack, the stack being formed by cascading and stacking at least two metal-air battery monomers, each battery monomer including a monomer frame (1), a positive electrode (2) symmetrically arranged on both sides of the monomer frame (1), and a negative electrode (3) inserted into the monomer frame (1), characterized in that, The active positive pressure oxygen supply system of the stack comprises: A vent plate (22) disposed on the outside of the positive electrode (2) of the battery cell, the vent plate (22) being provided with a vent window (221) exposing the positive electrode (2), a plurality of vent grooves (222) being provided on the outer surface of the vent plate (22), and at least one end of all the vent grooves (222) being in communication with the vent window (221); The monomer frame (1) is provided with an air inlet (121) and an exhaust port (122) connected to the ventilation groove (222); the air inlets (121) of adjacent monomer frames (1) are connected one by one after the battery monomers are stacked and spliced to form an air inlet channel of the entire battery stack; the exhaust ports (122) of adjacent monomer frames (1) are connected one by one after the battery monomers are stacked and spliced to form an exhaust channel of the entire battery stack; a plurality of air flow channels connecting the air inlet channel and the exhaust channel are formed between the positive electrodes (2) of adjacent battery monomers through the ventilation windows (221) and the ventilation grooves (222) on the ventilation plate (22); wherein the air inlet channel is connected to a gas conveying device, and the exhaust channel is connected to a gas recovery device; the air inlet (121) is provided at the bottom of the monomer frame (1), and two exhaust ports (122) are provided, and the two exhaust ports (122) are symmetrically arranged on both sides of the top of the monomer frame (1); The outer surface of the single body frame (1) is provided with a guide groove (123) for connecting the ventilation groove (222) on the ventilation plate (22) with the air inlet (121) and the exhaust port (122) respectively, wherein one of the guide grooves (123) is arranged between the air inlet (121) and the bottom edge of the ventilation plate (22); the other is arranged horizontally above the top edge of the ventilation plate (22), and both ends of the guide grooves are connected with the exhaust port (122); Wherein, a ventilation groove (222) arranged along the width direction is provided between the ventilation window (221) and the length side of the ventilation plate (22); a ventilation groove (222) arranged along the length direction is provided between the ventilation window (221) and the width side of the ventilation plate (22); and the ventilation grooves (222) are all provided through the side of the ventilation plate (22) and the side of the ventilation window (221); one end of all the ventilation grooves (222) is connected to the ventilation window (221), and the other end extends to the end face of the ventilation plate (22); in a battery stack with multiple battery cells cascaded and stacked, the cell frames of adjacent battery cells are pressed and contacted through the ventilation plate (22); and the corresponding ventilation grooves (222) and the ventilation windows (221) on the ventilation plate (22) form an air flow channel connecting the positive electrode of the battery and the outside of the battery; The air flow entering through the air inlet (121) enters the ventilation grooves (222) on the ventilation plate (22) through the diversion grooves (123) at the bottom respectively, and enters the positive electrode (2) along the ventilation grooves (222) through the ventilation windows (221), ensuring the continuous supply of oxygen required for the discharge reaction of the positive electrode (2). Part of the flowing air flow is directly discharged from the fuel cell stack through the ventilation grooves (222) on both sides of the ventilation plate (22), or enters the exhaust port (122) through the upper diversion grooves (123) from the ventilation grooves (222) on the upper part of the ventilation plate (22) when the ventilation grooves (222) on both sides are closed.

2. The active positive pressure oxygen supply system of the metal-air battery stack according to claim 1, characterized in that: The ventilation windows (221) on the ventilation plate (22) are located within the projection range of the internal discharge reaction area of the battery cell on the positive electrode (2).

3. The active positive pressure oxygen supply system for a metal-air battery stack according to claim 1, characterized in that: Partition ribs (23) are arranged in the ventilation windows (221). The partition ribs (23) divide the ventilation windows (221) into a plurality of ventilation window units. Ventilation grooves (222) are also arranged on the partition ribs (23). Adjacent two ventilation window units are communicated through the ventilation grooves (222) on the partition ribs (23).

4. The active positive pressure oxygen supply system for a metal-air battery stack according to claim 3, characterized in that: The ventilation grooves (222) are arranged along the length direction and the width direction of the ventilation plate (22).

5. The active positive pressure oxygen supply system for a metal-air battery stack according to claim 1, wherein: Both the air inlet (121) and the exhaust port (122) are arranged to penetrate along the cascading direction of the single cell frame (1).

6. The active positive pressure oxygen supply system for the metal-air battery stack according to any one of claims 1-5, characterized in that: The ventilation grooves (222) have a semi-circular cross-section, an elliptical cross-section or a polygonal cross-section.

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