CN113964420B

CN113964420B - Metal-air battery

Info

Publication number: CN113964420B
Application number: CN202111243583.7A
Authority: CN
Inventors: 宁静
Original assignee: Aluminum Energy Times Energy Co ltd
Current assignee: Aluminum Energy Times Energy Co ltd
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2023-04-14
Anticipated expiration: 2041-10-25
Also published as: CN113964420A; WO2023071803A1

Abstract

The present invention relates to a metal-air battery comprising: a housing; a metal anode including a bottom surface; an electrolyte, at least a bottom surface of the metal anode being in contact with a surface of the electrolyte; an anode support including an upper portion, a middle portion and a lower portion, the upper portion having a width less than a width of the middle portion; an air cathode including an upper surface and a lower surface; wherein the upper portion of the anode support supports the bottom surface of the metal anode such that the spacing between the bottom surface of the metal anode and the upper surface of the air cathode is maintained at 2 to 5mm. The invention can greatly increase the quantity of available metal of the anode, thereby greatly prolonging the working period of the metal-air battery.

Description

Metal-air battery

Technical Field

The present invention relates to a metal-air battery, and particularly, to an aluminum-air battery.

Background

The basic principles and major advantages and disadvantages of metal-air batteries, particularly aluminum-air batteries, are well known in the art. Around the year 2000 of the public yuan, the driving mileage of the electric automobile charged once is seriously insufficient, and the aluminum-air battery is used as a potential feasible scheme to participate in the competition of the vehicle-mounted battery. Heretofore, aluminum-air batteries have been out of date of lithium ion batteries in the competition of on-board power battery packs (capacity of tens to hundreds of kilowatt-hours).

However, in response to the demand for larger capacity applications, such as battery-powered ships sailing across the ocean, not only is the electricity demand thousands of times greater than that of electric vehicles, but there is no charging possibility in a voyage of thousands of kilometers or even tens of thousands of kilometers. Lithium ion batteries clearly do not meet this demand, but the aluminum-air battery technology route is theoretically feasible.

Even such large-to-ultra large-sized metal-air batteries, which have capacities several hundred to several ten thousand times greater than those of on-board batteries, more precisely, are called "(megawatt-level) metal fuel power plants", and should be actually easier to implement than on-board batteries. Because the most important defects of the existing vehicle-mounted aluminum-air battery pack are related to factors such as narrow space, load limit and low power of a car. For example, the vehicle-mounted battery has insufficient power density (< 500 mw/cm) ² ) The power of the aluminum-air battery automobile is not high (less than or equal to 20 kw), so although the aluminum-air battery automobile with the travel of more than thousands of kilometers is reported in the prior art, the acceleration characteristic and the climbing performance are difficult to report. And 300mw/cm in land/ship-borne ultra-large-scale (megawatt) metal-air battery pack with unconstrained volume/weight ² The power density of (2) can be greatly regarded. For another example, the electrolyte circulation system of an aluminum-air battery must include a process for separating impurities and regenerating the electrolyte, which is a work that requires tens of thousands of investments in a workshop, and the workshop is simplified, reduced and then hard plugged into a passenger car with a small volume, and the effect is certainly not as good as that of a super-large-scale metal-air batteryThe actual process plant in the gas cell stack.

The theoretical concept of the aluminum fuel power plant is pushed to be practical, so that the technical problems existing in many past metal-air batteries are solved continuously, and a new technical problem is added: how to perform the addition/replacement of fuel metal aluminum.

There are two main types of fuel addition/replacement in existing power plants. The first type is supplement at any time during the operation process, such as continuous input of coal/oil/gas into a boiler by a thermal power plant; the second type is a reserve, such as a nuclear power plant shutdown for refueling, tens of nuclear fuel assemblies at a time, and a new nuclear fuel assembly can be continuously operated for a long time (e.g., 1 to 2 years).

An aluminum-air battery "aluminum fuel power plant" involves thousands of battery cells, and the continuous input of metal fuel to such cells is much more difficult than the input of fuel to only one or a few boilers of a thermal power plant.

Therefore, the fuel replacement of the metal-air battery is the most feasible scheme that a fuel replacement mode similar to that of a nuclear power station is adopted, and the metal fuel replaced each time can ensure that the battery pack continuously operates for a long time (for example, 3 months to 1 year)

During normal operation of the aluminum-air battery, aluminum on the surface layer of the anode is continuously dissolved in the electrolyte, so that the distance between the two polar plates of the air cathode and the aluminum anode is gradually enlarged, which is an inherent characteristic of the battery. The distance between the two polar plates of the air cathode and the aluminum anode has a great influence on the output power of the aluminum-air battery, the output power of the battery is rapidly reduced due to the increase of the distance, and in order to ensure the stable output power, the distance between the anode and the cathode needs to be kept basically constant.

For this reason, in order to realize an ultra-large capacity metal-air battery (megawatt metal fuel power plant), it is urgently necessary to provide a metal-air battery: firstly, the metal anode is stored with sufficient metal to meet the requirements for long-term operation (continuous operation for more than 3 months), and secondly, appropriate measures are taken to keep the distance between the metal anode and the air cathode substantially constant.

Disclosure of Invention

In view of the foregoing disadvantages of the prior art, the present invention provides a metal-air battery that satisfies the above need, comprising:

(1) A housing;

(2) A metal anode including a bottom surface;

(3) An electrolyte, at least a bottom surface of the metal anode being in contact with a surface of the electrolyte;

(4) An anode support member including an upper portion, a middle portion and a lower portion, the upper portion having a width less than a width of the middle portion;

(5) An air cathode, the air cathode including an upper surface and a lower surface, the air cathode being positioned below the metal anode and the electrolyte;

wherein the upper portion of the anode support supports the bottom surface of the metal anode such that the spacing between the bottom surface of the metal anode and the upper surface of the air cathode is maintained at 2mm to 5mm.

According to one embodiment of the invention, the metal anode is a thickened metal anode, the thickness H of the metal anode is at least 15mm and at most 1000mm, the metal is selected from the group consisting of aluminium, zinc, magnesium or iron; the area of the upper portion of the anode support contacting the bottom surface of the metal anode is not greater than the area of a circle having a diameter of 2 mm.

According to one embodiment of the invention, the anode support is in the shape of a mushroom, the anode support comprising mushroom heads corresponding to an upper part and a middle part of the anode support and mushroom stems corresponding to a lower part of the anode support, the height h4 of the mushroom heads being between 2mm and 5mm; the air cathode comprises a preformed hole and a supporting column for supporting the air cathode; the mushroom stems are fixed to the support posts through the preformed holes in the air cathode.

According to one embodiment of the present invention, the air cathode comprises, in order from top to bottom, a catalyst layer, a current collection layer, and a gas diffusion layer, the gas comprising air or oxygen; the air cathode divides the shell into a first area and a second area; the first region includes an electrolyte region and a catalyst layer located below the electrolyte region, and the second region includes a gas diffusion region and a gas diffusion layer located above the gas diffusion region.

According to one embodiment of the invention, the electrolyte zone comprises an inlet for the electrolyte and an overflow for the electrolyte, the inlet for the electrolyte being arranged on the air cathode or on the housing of the electrolyte zone.

According to one embodiment of the invention, a stationary sealed balloon, preferably a shock-absorbing sealed balloon, of the metal anode is arranged above the overflow opening of the electrolyte, the height h5 of the overflow opening of the electrolyte from the upper surface of the air cathode being greater than h4 and from 5mm to 10mm.

According to one embodiment of the invention, the gas diffusion zone is a closed space provided with an air or oxygen inlet and an air or oxygen outlet.

According to one embodiment of the invention, the number of anode supports is at least 3.

According to one embodiment of the invention, the material constituting the anode support comprises a silicon carbide ceramic material and a modified product of polytetrafluoroethylene, preferably a silicon carbide ceramic material.

According to one embodiment of the invention, the cross-section of the housing is rectangular or square, preferably square, and the material of the housing comprises corrosion-resistant, impact-resistant, insulating materials, such as ceramics and plastics; the cross-section of the metal anode is rectangular or square, preferably square.

Based on the above, the metal-air battery of the present invention can greatly prolong the normal operation period of the metal anode, and maintain the output power constant during the operation period.

Drawings

The invention is further illustrated, but not limited, by the following specific embodiments in conjunction with the accompanying drawings.

In the drawings:

fig. 1 shows a schematic cross-sectional view of the structure of a metal-air battery according to an embodiment of the present invention.

Fig. 2 is a partially enlarged schematic view of the structure of the metal-air battery shown in fig. 1.

Fig. 3 is a plan view of the structure of the metal-air battery of fig. 1.

Fig. 4 is a top view of the structure of the metal-air cell of fig. 1 after removal of the metal anode.

Fig. 5 shows a schematic cross-sectional view of the structure of a metal-air battery according to another embodiment of the present invention.

Fig. 6 is a plan view of the structure of the metal-air battery shown in fig. 5.

Fig. 7 is a top view of the structure of the metal-air cell of fig. 5 after removal of the metal anode and the shock absorbing sealing bladder.

Fig. 8 is a schematic cross-sectional view showing the structure of the metal-air battery shown in fig. 5 after the addition of an upper cover.

Fig. 9 shows a schematic diagram of an experimental setup for a metal-air battery according to an embodiment of the present invention.

Fig. 10 shows a graph of output power versus time for a metal-air battery of one embodiment of the present invention.

Description of the reference numerals:

1. a case (or battery box);

1a, an electrolyte area;

1b, a gas diffusion region;

2. thickening an aluminum anode;

3. an air cathode;

3.1, a catalyst layer;

3.2, a current collection layer;

3.3, a gas diffusion layer;

4 _N /4 ₁ /4 ₂ /4 ₃ /4 ₄ /4 ₅ /4 ₆ /4 ₇ /4 ₈ aluminum anode supports (or aluminum anode footplates);

4A _N a support column of aluminum anode support (stepping stone) (where N is a positive integer of 1 to 8);

5. an electrolyte;

5a, an inlet of electrolyte;

5b, an overflow outlet of the electrolyte;

6a, air/oxygen inlet;

6b, an air/oxygen outlet;

7. a shock-absorbing sealing air bag;

8. negative wire (coiled in spiral shape to make aluminum anode consume, descend and stretch out);

9. an upper cover;

l1, the side length of the inner wall of the shell (or the battery box);

d1, wall thickness of the case (or battery case);

l2, the side length of the aluminum anode;

d2, the distance between the edge of the aluminum anode and the opposite inner wall of the shell;

h4, height of mushroom head;

h5, the height between the overflow outlet of the electrolyte and the upper surface of the air cathode;

H. the thickness or height of the aluminum anode is increased.

In the above reference numerals, the same or similar reference numerals denote the same or similar elements.

Detailed Description

The present invention will be described in detail below by way of specific embodiments. However, the invention is not limited thereto.

In addition, in order to highlight the features and advantages of the present invention, no reference or detail is made to terms, structures/compositions, components/ingredients, test equipment and methods, etc., which have the meanings commonly understood by those skilled in the art.

In addition, the terms "first" and "second" in the present invention serve only to distinguish terms, and do not have sequential meanings of the ordinal words themselves. In addition, the numerical ranges of the present invention include the end values, any positive integer between the end values, a range composed of the end values and the positive integer, and a range composed of any one of the positive integers and another positive integer.

The term "air battery" used in the present invention is one of chemical batteries. The construction principle is similar to that of a dry cell except that the oxidant is taken from the oxygen in the air. For example, there is an air battery which uses zinc as a negative electrode, sodium hydroxide as an electrolyte, and porous activated carbon as a cathode, and thus can adsorb oxygen in the air to replace an oxidizing agent (e.g., manganese dioxide) in a general dry battery.

The term "metal-air battery" used in the present invention is a metal having a more negative electrode potential, such as aluminum, zinc, magnesium, iron, etc., as a negative electrode, and oxygen or pure oxygen in the air as an active material of a positive electrode. The electrolyte solution of the metal-air battery generally adopts alkaline or neutral electrolyte aqueous solution.

The term "anode" as used herein refers to the electrode at which oxidation occurs. In a galvanic cell, the anode is the negative electrode, electrons flow from the negative electrode to the positive electrode, and current flows from the positive electrode to the negative electrode. The cations in the solution move to the positive electrode and the anions move to the negative electrode. Accordingly, the term "cathode" as used herein refers to the pole where the reduction takes place. In a galvanic cell, the cathode is the positive electrode.

The term "electrolyte" as used herein refers to the medium used by a chemical battery to provide ions for the normal operation of the battery and to ensure that the chemical reactions occurring during the operation of the battery are reversible. In the present invention, the electrolyte commonly used includes potassium hydroxide, sodium chloride, and the like.

The term "housing" as used herein generally refers to a battery compartment.

As used herein, the term "anode support" is used interchangeably with "anode footplate" (e.g., aluminum anode footplate).

According to a preferred embodiment of the present invention, there is provided an aluminum-air cell with a thickened anode, comprising at least the following components:

(1) The cell box is divided into two independent upper and lower regions by the sheet-shaped air cathode, the upper portion is an electrolyte region, and the lower portion is a gas diffusion region.

(2) The anode foot-rest stones are mushroom-shaped, the number of the anode foot-rest stones is N, wherein N is a natural number, and N is more than or equal to 3 and less than or equal to 8; the bottom surface of the thickened anode is supported by the spherical surface of the mushroom head upwards, the lower plane of the mushroom head presses the upper surface of the air cathode, and the mushroom handle penetrates through the N preformed holes of the air cathode and is fixed on the corresponding support column.

(3) And a thickened aluminum anode inserted into the electrolyte region from above, the bottom surface of the anode being held in the air by the N mushroom heads of the stepping stone.

Preferably, the height h4 of the mushroom head of the anode stepping stone is 2mm to 5mm.

Preferably, the thickness H of the aluminum anode is 15mm to 1000mm.

Preferably, the height h5 of the overflow port of the electrolyte (from the upper surface of the air cathode) is 5mm to 10mm.

Preferably, the catalyst layer of the air cathode faces upward and the gas diffusion layer faces the ground.

Specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. These specific embodiments are merely illustrative and explanatory of the invention and do not set forth any limitations of the invention. Various changes, modifications and alterations to these particular embodiments will occur to those skilled in the art, which fall within the spirit and scope of the invention.

The thickened aluminum anode is arranged above and below the air cathode

One of the basic inventive concepts of the present invention is: through the upper and lower arrangement of thickening aluminium anode 2 and air cathode 3 under, after thickening aluminium anode 2 is dissolved by electrolyte 5 with the bottom surface of electrolyte 5 contact, thickening aluminium anode 2 utilizes the effort of its own weight, and automatic downstream keeps with mushroom-shaped aluminium anode foot pad stone 4 with continuation _N Small-area contact (the contact area is not more than the area of a circle with the diameter of 2 mm), thereby solving the inherent defect that the distance between the air cathode and the aluminum anode is gradually enlarged from the beginning of discharge in the prior art. In addition, this small area contact also allows the bottom surface of the entire thickened aluminum anode 2 to be better uniformly dissolved in the electrolyte 5.

Mushroom anode foot pad stone

Anode foot rest stone 4 _N For isolating the thickened aluminum anode 2 from the air cathode 3. "stepping stone" means that the spatial position of the thickened aluminum anode 2 is limited except in the lower direction: none of the anterior-posterior-left-right-superior is fixedly constrained (as shown in figures 1, 2, 5 and 8). The purpose of this design is to ensure the bottom surface of the thickened aluminum anode 2 and the air cathodeThe distance between the upper surfaces of the thickened aluminum anodes 2 is 2mm to 5mm, and the distance between the bottom surfaces of the thickened aluminum anodes 2 and the upper surface of the air cathode 3 can be automatically adjusted by utilizing the self weight of the thickened aluminum anodes 2, so that the thickened aluminum anodes are constant at 2mm to 5mm. This is because, as mentioned earlier, an increase in the pitch will result in a rapid decrease in the output power of the battery. In general, the spacing of 2mm to 5mm has a better power output.

The anode stepping stone of the present invention is not particularly limited in shape as long as it can support a metal anode and keep the distance between the metal anode and an air cathode within a certain range.

As a preferred embodiment, the anode foot stone of the present invention has an overall shape preferably in the form of a mushroom divided into an upper part, a middle part and a lower part, the upper part having a width smaller than that of the middle part, and specifically, including mushroom heads corresponding to the upper part and the middle part of the anode foot stone and mushroom stems corresponding to the lower part of the anode foot stone; the spherical surface of the head part of the mushroom supports the bottom surface of the thickened aluminum anode 2 upwards. The arc shape of the spherical surface of the mushroom head enables the electrolyte 5 to permeate into the aluminum anode foot rest stone 4 from the side surface _N Of the bottom plate. In this way the entire bottom surface of the thickened aluminum anode 2 is better evenly dissolved in the electrolyte 5.

Aluminum anode foot pad stone 4 _N The mushroom head height h4 of (a) is a very important parameter that determines the spacing between the upper surface of the air cathode and the bottom surface of the aluminum anode. Too large a distance reduces the output of the battery, and too small a distance affects the flow of the electrolyte and also the output. The height h4 of the mushroom head of the embodiment of the present invention is preferably 2mm to 5mm.

The aluminum anode foot rest stone 4 of the invention _N The mushroom stem passes through a preformed hole of the air cathode 2 and is fixed on the corresponding aluminum anode foot rest stone 4 _N Support column 4A of _N As shown in figures 1 and 2. The design proposal is that the weight of the thickened aluminum anode 2 is enabled to pass through the aluminum anode foot rest 4 _N And a support column 4A _N And is transferred to the bottom surface of the battery case 1, and ultimately ensures that the air cathode 3 does not bear excessive weight of the thickened aluminum anode 2 or impact due to bumping.

Aluminum anode foot pad stone 4 _N The number of (B) is represented by N, in particular from 4 ₁ Numbered sequentially up to 4 _N Aluminum anode foot pad stone 4 _N The number N of (B) is 3. Ltoreq. N.ltoreq.8, preferably 4. Ltoreq. N.ltoreq.8 (see FIGS. 1, 4 and 7). Aluminum anode foot pad stone 4 _N Is 3 to provide stable support for the aluminum anode, at least 1 should be reserved as a backup to prevent certain aluminum anode stepping stone 4 _N Broken or trapped in the defects of the thickened aluminum anode 2; aluminum anode foot pad stone 4 _N The maximum number of the anode foot stones is not limited in theory, but since the presence of the anode foot stones requires the air cathode 3 to be provided with mounting holes, which deteriorates the performance of the air cathode to some extent, the number of the anode foot stones is not too large, and preferably the maximum number is 10, more preferably 8. In a preferred embodiment of the present invention, 4 aluminum anode stepping stones 4 are used ₁ 、4 ₂ 、4 ₃ And 4 ₄ (ii) a In another preferred embodiment of the present invention, 8 aluminum anode footplates 4 are used ₁ 、4 ₂ 、4 ₃ 、4 ₄ 、4 ₅ 、4 ₆ 、4 ₇ And 4 ₈ 。

Aluminum anode foot pad stone 4 _N The material of (2) needs to meet the conditions of electrical insulation, stable chemical property, corrosion resistance, high hardness, wear resistance and the like. In a preferred embodiment of the invention, an aluminum anode stepping stone 4 _N The material (D) is not particularly limited, but preferably a silicon carbide ceramic material, and a modified product of Polytetrafluoroethylene (PTFE), such as ethylene-tetrafluoroethylene copolymer (ETFE), may suffice.

Thickened aluminum anode

In a preferred embodiment of the present invention, a thickened aluminum anode 2 is inserted into the electrolyte region 1a from above the battery case 1, the bottom surface of the thickened aluminum anode 2 and the anode stepping stone 4 _N The mushroom heads are contacted.

As previously mentioned, in the prior art, aluminum-air cells have adopted a "thinning" strategy to maintain the magnitude of the drop in output power during operation within an acceptable range, where the anode plate thickness is typically 1mm to 3mm. In contrast, the present invention utilizes a "thickened" aluminum anode and the overall structure of the cell designed by the present invention allows the allowable thickness dimension of the aluminum anode to be greatly increased, thereby reducing aluminum anode replacement and making the cell structure simple, efficient and reliable. The range of the thickness of the anode of the present invention depends on the hardness of the anode material and the upper surface area of the anode supporter, and is not particularly limited. The thickness of the aluminium anode of the invention may be, among others, at least 3 times, preferably 100 times, even up to several hundred times or more (e.g. 200 times) the thickness of prior art aluminium anodes (typically less than 5 mm). In particular, the aluminum anodes of the present invention are suitably in the thickness range 15mm to 1000mm, preferably 24mm to 1000mm. In a preferred embodiment of the invention, the thickness H of the thickened aluminum anode 2 is 24mm; in another preferred embodiment of the invention, the thickened aluminum anode 2 has a thickness H of 1000mm.

In a preferred embodiment of the invention, the aluminium anode is square in cross-section.

Air cathode

A significant feature of the present invention is that the battery case 1 is divided into two independent functional areas, upper and lower, by a sheet-like air cathode 3, and strictly divided into: the upper part is an electrolyte region 1a and the lower part is a gas diffusion region 1b. In contrast, in the prior art, the sheet-shaped air cathode generally divides the battery case into left and right portions, and the electrolyte region (or gas diffusion region) is left or right, and there is no specific direction requirement.

In addition, in the prior art, the basic shape of the air cathode is a multilayer sheet structure: so-called multilayers, generally comprising at least a catalyst layer 3.1, a current collection layer 3.2 and a gas diffusion layer 3.3; the sheet-like shape means that the catalyst layer 3.1, the current collecting layer 3.2 and the gas diffusion layer 3.3 are laminated together to form a sheet having a thickness of less than 2 mm. In sharp contrast thereto, in the preferred embodiment of the invention, the basic shape of the air cathode 3 is also preferably a multilayer sheet structure, but the directions of use are specified in particular, i.e., the catalyst layer 3.1 is oriented upward, constitutes the electrolyte region 1a together with the upper half of the battery case 1, the gas diffusion layer 3.3 is oriented downward (i.e., in the direction of the ground), and constitutes the gas diffusion region 1b together with the lower half of the battery case 1 (as shown in fig. 2). The layout scheme that the upper part is the electrolyte area 1a and the lower part is the gas diffusion area 1b provides a simple and reliable scheme for the anode to automatically adjust/maintain the distance between the anode and the cathode by utilizing the self weight, thereby realizing the invention.

Electrolyte/gas diffusion zone

The electrolyte 5 of the present invention is not particularly limited, and may be an electrolyte commonly used in the field of batteries, such as an alkaline or neutral electrolyte, for example, potassium hydroxide, sodium hydroxide or sodium chloride.

The electrolyte region 1a contains an inlet 5a for the electrolyte 5 and an overflow 5b for the electrolyte 5. Preferably, the inlet 5a of the electrolyte 5 is arranged on the air cathode 3, and one of the advantages of this arrangement is that when the battery is shut down, the inlet 5a of the electrolyte 5 can be used as a discharge port of the electrolyte 5, so that the electrolyte 5 in the battery can be conveniently emptied, and thus, the thickened aluminum anode 2 is separated from contact with the electrolyte 5 during the shut down process to avoid the thickened aluminum anode 2 being dissolved by the electrolyte 5 during the shut down process, thereby prolonging the service life of the thickened aluminum anode 2; another advantage is that it facilitates the evacuation of contaminants present between the thickened aluminum anode 2 and the air cathode 3 during cleaning.

In the present invention, the height h5 of the overflow opening 5b of the electrolyte 5 from the upper surface of the air cathode 3 is another important parameter. First, as shown in fig. 2, the height h5 must be greater than the height h4 of the mushroom head to ensure that the bottom surface of the thickened aluminum anode 2 is immersed in the electrolyte 5; secondly, the difference between the height h5 and the height h4 is the height at which the side of the thickened aluminum anode 2 is immersed in the electrolyte 5, and unnecessary loss occurs on the surface of the thickened aluminum anode 2 immersed in the electrolyte 5, so that the height h5 cannot be too much higher than the height h 4. In a preferred embodiment of the present invention, the height h5 of the overflow outlet 5b of the electrolyte 5 from the upper surface of the air cathode 3 is 5mm to 10mm, so that the thickened aluminum anode 2 can obtain higher output power of the battery at lower cost and maximally extend the service life of the thickened aluminum anode 2.

The gas diffusion zone 1b is a closed space provided with an air/oxygen inlet 6a and an air/oxygen outlet 6b, which enables air/oxygen to be cyclically replenished.

Fixed sealing air bag

As described above, the anode position can be automatically adjusted by the own weight of the thickened aluminum anode 2. However, in many cases, such as the application of batteries to ships, airplanes, and automobiles, severe sloshing and bumping conditions are encountered. If the position of the aluminum anode is not constrained at this time, it is highly likely to collide with other parts of the cell and cause damage.

For this purpose, in a preferred embodiment of the present invention, a fixed sealing air bag, preferably a shock-absorbing sealing air bag 7 (shown in fig. 5 and 6) is provided above the overflow port 5b of the electrolyte 5 in the battery case 1. Before inserting the thickened aluminum anode 2 to make the battery work, the shock-absorbing sealing air bag 7 is contracted in a special groove in the battery box 1 by air suction, so that the shock-absorbing sealing air bag 7 is not influenced when the thickened aluminum anode 2 is inserted. When the battery works, the damping sealed air bag 7 is inflated to expand, the thickened aluminum anode 2 is hooped tightly, and the first effect is to generate a sealing effect so as to prevent the electrolyte 5 from leaking during bumping; the second function is to provide an adjustable constraint force, which can prevent the thickened aluminum anode 2 from colliding with the inner wall of the battery box 1 below or around, and can also relax the tightening degree in due time, so that the bottom surface of the thickened aluminum anode 2 and the anode foot rest 4 can be ensured _N And (4) automatically leveling.

Battery box

In a preferred embodiment of the invention, the shape of the battery case 1 is a simple geometric structure, such as a rectangular parallelepiped of rectangular cross section or a cube of square cross section, preferably a cube of square cross section; the material of the battery case 1 is a corrosion-resistant, impact-resistant insulating material such as ceramic, plastic, or the like. As shown in fig. 1 and 3, L1 represents the side length of the inner wall of the battery case 1, d1 represents the wall thickness of the battery case 1, L2 represents the side length of the aluminum anode, and d2 represents the distance between the edge of the aluminum anode and the corresponding inner wall of the battery case 1.

According to the aluminum-air battery provided by the invention, the normal working period of the aluminum anode can be greatly prolonged to 10-200 times of the prior art, and the fluctuation rate of the output power is ensured to be less than 10% in the working period.

Examples

The present invention will be described and illustrated below with reference to specific examples, but the present invention is not limited thereto. Other parts related to the aluminum-air battery, such as the composition and efficiency of the air cathode, the composition and storage and circulation system of the electrolyte, the air circulation system, the circuit connection device, etc., are all considered as known in the art, and those skilled in the art can conventionally understand and determine their corresponding specific technical contents, which are omitted herein and will not be described in detail. In addition, the following materials and experimental equipment and experimental parameters thereof are not specifically described and are routinely available to those skilled in the art.

Example 1: thickened anode aluminum air battery lighting device

Example 1 an experimental lighting fixture was constructed using 8 (B1-B8) identical home-made thickened anode aluminum-air cells in series, as shown in fig. 9. Wherein each part is respectively:

1. a plastic battery case: a battery shell with the inner wall L1 being 54mm in side length and the wall thickness D1 being 10mm in thickness is printed by a Snapmaker three-D Printer of Chengdui three-dimensional science and technology Limited company by using a 3D Printer fiber 1.75ABS (namely acrylonitrile-butadiene-styrene copolymer) material of an Amazon online shopping printing consumable MECH.

2. Thickening an aluminum anode: ordinary industrial-grade aluminum bars are purchased in local metal markets, and are cut into 4 different specifications of thicknesses (heights) of 24mm (B1-B4), 100mm (B5-B6), 500mm (B7) and 1000mm (B8) by selecting square sections with the specification of 2X 2 (inches, 50.8mm long and 50.8mm wide).

3. Air cathode (self-made)

(a) Preparing materials: 2g of 95% multi-walled carbon nanotube, 5g of activated carbon (analytically pure, particle size of 200 meshes), 1g of alpha manganese dioxide (battery grade, particle size less than or equal to 50 nm), 700ml of distilled water, (99.9%) of anhydrous ethanol 200ml, and 2g of PTFE (namely polytetrafluoroethylene) (calculated by 60% aqueous dispersion); 2g of polyethylene glycol (PEG). ( The above distilled water and absolute ethyl alcohol are obtained from local places, and others are obtained from Taobao network purchase, wherein: manganese dioxide was purchased from "nannocai wood"; PTFE is purchased from "yoyo new energy"; 95% multi-walled carbon nanotubes were purchased from "suzhou carbofeng graphene"; activated carbon was purchased from "Shanghai chemical reagents"; polyethylene glycol purchased from 'Yatai combined chemical engineering' )

(b) Dispersing and mixing;

(c) 1g of alpha manganese dioxide and 200ml of distilled water are added into a mixing container, and the mixture is subjected to ultrasonic and stirring combined treatment for more than or equal to 60 minutes, wherein the ultrasonic power is more than or equal to 10w/cm ² Stirring at 180 rpm;

(d) 2g of dispersing agent (polyethylene glycol PEG), 200ml of absolute ethyl alcohol and 500 ml of distilled water are added into the container, and the ultrasonic and stirring combined treatment is carried out for more than or equal to 15 minutes;

(e) 5g of activated carbon is added into the container, and the ultrasonic and stirring combined treatment is carried out for more than or equal to 60 minutes;

(f) 2g of carbon nano tube is added into the container, and the ultrasonic and stirring combined treatment is carried out for more than or equal to 60 minutes;

(g) Adding 2g of PTFE into the container, and carrying out ultrasonic and stirring combined treatment for more than or equal to 120 minutes;

(h) Placing the dilute slurry and the container in an electric pressure cooker, opening the cover, heating to 100 ℃ (centigrade)/60 minutes, heating the dilute slurry container in water bath to eliminate ethanol components in the slurry, closing the cover of the cooker, heating to 120 ℃/3 hours, and accelerating the agglomeration-precipitation process of the catalyst slurry;

(i) Taking out the slurry container from the pressure cooker, wherein the slurry is in a layered state with a clear upper layer and a dark lower layer, skimming the clarified liquid and retaining the concentrated liquid → stirring again → standing and clarifying again → skimming the clarified liquid and retaining the more concentrated slurry, and circulating for a plurality of times until the slurry becomes thick paste → stirring and kneading to form non-sticky catalyst mud mass;

(j) Rolling the non-sticky catalyst mud into sheets of about 5mm, and cutting into catalyst green bodies of 54mm by 54 mm;

(k) The current collecting layer is a 40-mesh pure nickel net (Taobao net is purchased from Kanwei wire gauze), cut into a square block of 64mm multiplied by 64mm, and provided with a foot stone preformed hole and an electrolyte overflow hole according to the designed position;

(l) Taking a nickel sheet with the width of 5mm and the thickness of 0.5 mm, welding a circle along the edge of a nickel screen to be used as the limit of the height of a catalyst layer, wherein the length of one nickel sheet exceeds 100mm, and the part which exceeds the nickel screen is used as the anode lead of a battery;

(m) placing a catalyst green-pressing body with the thickness of 54mm multiplied by 54mm in the middle of a current-collecting layer nickel net, drying at the low temperature of 120 ℃ for 60 minutes, taking out, placing under a press, applying the pressure of 20MP and keeping the pressure for 5 minutes, and combining the current-collecting layer and the catalyst layer into a whole;

(n) taking out the air cathode semi-finished product after pressure relief, brushing 5-10% of PTFE emulsion on the back of the catalyst layer for several times, and forming a PTFE thin layer with the thickness of 50-100 microns as a gas diffusion layer.

(o) using a blue sky SXQC-5-16 programmable atmosphere protection box furnace, carrying out heat treatment on the air cathode for 12 hours under the protection of nitrogen at 270 ℃, eliminating residual ineffective (harmful) components, stabilizing the fine structure of each layer, and obtaining the final finished product of the air cathode.

4. Anode support/anode footpad; using 4 anode supports, reference 4 ₁ -4 ₄ "95 zirconia ceramic balls" 6 mm in diameter as support/stepping stone (available from "two-star mill mills on elutriation net");

supporting the foot stone 4A ₁ -4A ₄ Considered as part of the housing, is formed simultaneously when the battery housing is 3D printed. The top of the supporting seat is printed to form a circular hole recess with the diameter of 6 mm and the depth of 3mm. And the air cathode is arranged in a clamping groove of the battery shell, the lower hemisphere of the ceramic ball is bonded and fixed in the clamping groove, and the upper hemisphere of the zirconia ceramic ball becomes a support piece with the height h4= 2-3 mm.

5. Electrolyte and electrolyte circulation branch; wherein "5" represents an electrolytic solution. This example used distilled water and sodium hydroxide (commercially available from Amazon, belle Chemical food grade) to formulate a 4M molar solution of sodium hydroxide by itself.

5a, electrolyte inlet: the battery shell is reserved and formed during 3D printing, and the embodiment also takes the electrolyte input plastic hose as an electrolyte inlet;

5b, an electrolyte overflow outlet: 3D printing is performed, and the electrolyte overflow pipeline is also taken as an electrolyte outlet;

5c, a flow control valve; the flow rate of the drip quantity per minute is adjusted by adopting a common medical disposable transfusion controller;

5s, a new electrolyte storage tank 10L-20L plastic barrel;

5g, used electrolyte recycling tank after use.

In fig. 9, the 6a air inlet and the 6b air outlet form an air circulation branch, and both the 6a air inlet and the 6b air outlet are formed when the 3D printing housing is formed.

And T, a test unit for testing and recording the voltage, the current and the power output by the battery, wherein the test unit is provided with a data storage card.

C: the DC/AC inverter converts a 12V DC to a 110V AC, which may be a conventional type for a vehicle.

U1 is an oxygenation pump which provides an air source for the aluminum air battery; amazon's on-line general fish bowl oxygenation pump EcoPlus XS10010 380GPH, nominal power consumption 13w.

U2 is a lighting bulb used for visually detecting the power output condition of a power supply, and is selected from Philips 110V and an LED common lighting bulb with nominal power consumption of 14w.

System connections (see experimental setup of figure 9):

1. electrical connection

The battery interior follows B1 (+) → B2 (-); b2 (+) → B3 (-); (ii) B7 (+) → B8 (-) connection; the negative electrode (aluminum bar) of the battery exterior B1 and the positive electrode of B8 were connected to the inlets E (-) and E (+) of the test cell T with leads.

2. Electrolyte (circulation) system

In the aluminum-air battery formed in series, since the electrolytes of different batteries are at different potentials, independent channels which are isolated from each other must be adopted, so that 8 independent electrolyte branches are required in embodiment 1.

The discharge product of aluminum must be carried away from the electrolyte region 1a by the electrolyte in time, otherwise, insoluble precipitate is formed after accumulation and adheres to the surface of the catalyst layer, thereby causing the output power to be reduced, which will interfere with the "output power characteristic" of the key index tested in this embodiment. Example 1a simple measure was taken of "fresh + appropriate amount" of electrolyte. The so-called "fresh" is a single use of the electrolyte, avoiding the recycling of the used electrolyte containing the discharge products. The electrolyte box 5s is arranged above the battery packs B1-B8 (more than or equal to 1 meter) to form a self-flow by using a fall, and finally enters the old electrolyte collecting box 5g, in order to control the proper flow of the electrolyte, pipelines of 8 disposable medical infusion bags and a flow regulating valve 5c are intercepted and connected to the outlet of the electrolyte box 5s, and the flow of each branch is regulated to be 300 milliliters per hour; another measure adopted in this embodiment is that the electrolyte overflow opening 5b is at the lower part, and bypasses to the upper part through the pipeline to form a liquid level control height h5 (h 5= 6-7 mm is set in this embodiment), which facilitates the discharge product to be discharged from the electrolyte region 5b to the outside of the battery.

3. Air/oxygen system: 4 output ports of the oxygenation pump are connected with 4 connectors of 1-to-2 connectors, and 8 branches are connected to the gas inlets 6a of the B1-B8 batteries through 10mm gas pipes.

The testing process comprises the following steps: after starting up, the system is continuously operated for 5 days for 120 hours, during which fresh electrolyte is replenished for the electrolyte storage barrel 5s as the case may be, and used electrolyte is recovered. The electrolyte bypass "flush" operation is performed once a day for 10 minutes, and the control valve 5c is adjusted to increase the electrolyte flow rate from about hourly-300 ml for normal operation to hourly-1500 ml.

And (3) testing results: visually observing each thickened aluminum anode, and stably sitting on the supporting piece/the foot stone under the action of the self weight of each thickened aluminum anode, wherein the thickness (height) of each anode is slowly reduced; the illumination lamp is on for a long time during the test period, and the naked eye can not feel the intensity change of the light.

At the end of 120 hours, the thickness of each aluminum anode was measured to decrease by 17.7mm. The power output-time curve shows a fluctuation rate of the output power of 7% over the entire operating period, wherein the fluctuation rate = (maximum output power 30.7-minimum output power 28.6)/nominal output power value 30w (see fig. 10). The aluminum-air battery of the present embodiment achieves a great extension of the normal operating cycle of the aluminum anode to 120 hours while keeping the output power constant during this operating cycle, since the fluctuation rate of the output power is only 7%, which ensures that the fluctuation rate of the output power is less than 10% during this operating cycle.

An ultra-large capacity metal-air battery is essentially a metal fuel power plant, and examples include, but are not limited to, a huge ship sailing across the ocean, and the application scenario can cover the needs of many consumers. The invention provides a simple and reliable solution for the problem of supplementing metal fuel for the ultra-large capacity metal-air battery pack.

The metal-air battery of the invention is used as a new energy with completely renewable fuel and zero carbon emission, and the perfection, popularization and popularization of the product have great economic value and environmental significance.

The basic concepts, features and advantages of the present invention have been described above in detail by way of specific embodiments and specific examples. However, various modifications, changes, substitutions and variations based on the specific embodiments and specific examples described above will be apparent to those skilled in the art and fall within the scope of the appended claims.

Claims

1. A metal-air battery, comprising:

(1) A housing;

(2) A metal anode including a bottom surface;

(3) An electrolyte, at least the bottom surface of the metal anode being in contact with a surface of the electrolyte;

(4) An anode support comprising an upper portion, a middle portion, and a lower portion, the upper portion having a width less than a width of the middle portion;

(5) An air cathode comprising an upper surface and a lower surface, the air cathode being positioned below the metal anode and the electrolyte;

wherein the upper portion of the anode support supports the bottom surface of the metal anode, the anode support maintains a spacing between the bottom surface of the metal anode and the upper surface of the air cathode of 2mm to 5mm, the anode support is shaped like a mushroom, the anode support includes a mushroom head and a mushroom stem, the mushroom head corresponds to the upper portion and the middle portion of the anode support, the mushroom stem corresponds to the lower portion of the anode support, a height h4 of the mushroom head is 2mm to 5mm; the air cathode comprises a preformed hole and a supporting column for supporting the air cathode; the mushroom stems are fixed to the support posts through the prepared holes in the air cathode,

the air cathode comprises a catalyst layer, a current collection layer and a gas diffusion layer from top to bottom in sequence, and the gas comprises air and oxygen; the air cathode divides the housing into a first region and a second region; the first region includes an electrolyte region and the catalyst layer positioned below the electrolyte region, and the second region includes a gas diffusion region and the gas diffusion layer above the gas diffusion region.

2. The metal-air cell of claim 1, wherein the metal anode is a thickened metal anode having a thickness H of at least 15mm and at most 1000mm, the metal being selected from aluminum, zinc, magnesium, or iron; the area of the upper portion of the anode support contacting the bottom surface of the metal anode is no greater than the area of a circle having a diameter of 2 mm.

3. The metal-air battery of claim 1, wherein the electrolyte region includes an electrolyte inlet and an electrolyte overflow outlet, the electrolyte inlet being disposed on the air cathode or on a housing of the electrolyte region.

4. The metal-air battery of claim 3, wherein a fixed sealed bladder of the metal anode is disposed above an overflow outlet of the electrolyte, a height h5 of the overflow outlet of the electrolyte from the upper surface of the air cathode being greater than a height h4 of the mushroom head and being 5mm to 10mm.

5. The metal-air battery of claim 4, wherein a shock absorbing sealed bladder of the metal anode is disposed over the overflow outlet of the electrolyte.

6. A metal-air battery according to any of claims 1-5, wherein the gas diffusion region is an enclosed space provided with an air or oxygen inlet and an air or oxygen outlet.

7. A metal-air battery according to any of claims 1-5, wherein the number of anode supports is at least 3.

8. A metal-air battery according to any of claims 1-5, wherein the material comprising the anode support comprises a modified product of a silicon carbide ceramic material and polytetrafluoroethylene.

9. A metal-air battery according to any of claims 1-5, wherein the material comprising the anode support comprises a silicon carbide ceramic material.

10. The metal-air battery of any of claims 1-5, wherein the housing is rectangular or square in cross-section, the material of the housing comprising a corrosion-resistant, impact-resistant insulating material; the section of the metal anode is rectangular or square.

11. The metal-air battery according to any one of claims 1 to 5, wherein the casing is square in cross section, and the material of the casing includes ceramics and plastics; the section of the metal anode is square.