A zinc-air battery

Abstract

The present invention relates to the technical field of zinc-air batteries, and in particular to a zinc-air battery. The air electrode sheet in the zinc-air battery of the present invention is waterproof and breathable, and the structural design of the zinc-air battery ensures the ingress of more air, maximizing the contact area between the air electrode sheet and the electrolyte, and allowing sufficient reaction on both sides of the negative electrode of the metal zinc paste battery cell. This results in excellent discharge performance for the zinc-air battery with this structure. When the voltage is maintained at a constant voltage of 0.9V, the specific capacity can reach over 700Ah / kg, the discharge energy density reaches over 670Wh / kg, the 24h current is over 3A, and the 72h current is over 1A.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc-air batteries, and in particular to a zinc-air battery. Background Art

[0002] Zinc-air batteries (ZABs) are metal-air batteries that use oxygen from air as the positive electrode and zinc as the negative electrode to generate energy. These batteries maintain a capacity loss of less than 5% per year after storage and exhibit low self-reactivity. Their significant advantages, including high capacity, high safety, low self-discharge, and low cost, have made them a popular battery technology.

[0003] In the current commercialization process, zinc-air batteries primarily utilize a convenient and reliable alkaline aqueous solution as the electrolyte. A key challenge is ensuring the battery's resistance to leakage. Due to their inherently open structure, zinc-air batteries, exposed to air, are prone to electrolyte leakage during use, leading to battery failure and even damage to electrical devices. Furthermore, energy density needs to be further improved. Summary of the Invention

[0004] The object of the present invention is to provide a zinc-air battery, which has a high energy density and is not prone to the problem of electrolyte leakage.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a zinc-air battery, comprising a first air electrode carbon sheet, a first positive electrode sheet, a metal zinc paste battery negative electrode, a second positive electrode sheet, a second air electrode carbon sheet and an electrolyte, which are arranged in sequence;

[0007] The electrolyte is filled in the entire cavity of the zinc-air battery;

[0008] The negative electrode of the metal zinc paste battery cell includes a metal current collector and a first zinc electrode and a second zinc electrode respectively arranged on both sides of the metal current collector;

[0009] The raw material for preparing the first zinc electrode or the second zinc electrode is metal zinc paste; the raw materials for preparing the metal zinc paste are composed of zinc powder, gel and water;

[0010] The electrolyte is a semi-solid electrolyte;

[0011] The first air electrode carbon sheet and the second air electrode carbon sheet each include a waterproof breathable membrane and a support frame with a catalyst on the surface, and the waterproof breathable membrane and the support frame with the catalyst on the surface are press-fitted;

[0012] The negative electrode of the metal zinc paste battery cell is wrapped by a shell with 9 grid windows;

[0013] The negative electrode of the metal zinc paste battery cell has a 9-grid structure, and the 9-grid structure is consistent with the reinforcement ribs of the 9-grid window openings of the shell;

[0014] It also includes a window cover plate, which includes a front cover, a rear cover and an upper cover; the window cover plate is located at the outermost side of the zinc-air battery, and the front cover and the rear cover of the window cover plate are 8-grid windows.

[0015] Preferably, the negative electrode of the metal zinc paste battery cell includes two tabs, and the tabs are not wrapped by the shell with 9-grid windows and extend to the outside of the zinc-air battery.

[0016] Preferably, the inner cross-section of the shell is provided with side steps and positioning posts for fixing the negative electrode of the metal zinc paste battery cell;

[0017] The outer side of the shell is provided with a sunken step for placing the first positive electrode sheet and the second positive electrode sheet.

[0018] Preferably, the first positive electrode sheet and the second positive electrode sheet each include two tabs, and the tabs extend to the outside of the zinc-air battery.

[0019] Preferably, the method for preparing the negative electrode of the metal zinc paste battery cell comprises the following steps:

[0020] Mix zinc powder, gel and water to make zinc paste;

[0021] The zinc paste is coated on both sides of the metal current collector to obtain the metal zinc paste battery negative electrode.

[0022] Preferably, the mass ratio of the zinc powder, gel and water is 30:(1-1.2):(5-6);

[0023] The gel comprises one or more of food starch glue, polyacrylamide, polyvinyl acetate, sodium carboxymethyl cellulose and polyurethane.

[0024] Preferably, the method for preparing the semi-solid electrolyte comprises the following steps:

[0025] Mixing potassium hydroxide, water and gel powder and allowing to stand to obtain the semi-solid electrolyte;

[0026] The mass ratio of the potassium hydroxide, water and gel powder is 345:1000:3.

[0027] Preferably, the gel powder comprises one or more of silicon dioxide, water-absorbing resin SAP, agar, potassium alginate, sodium alginate, polyacrylamide and a dispersant.

[0028] Preferably, the method for preparing the first air electrode carbon sheet or the second air electrode carbon sheet comprises the following steps:

[0029] mixing carbon powder, graphite, metal oxide and platinum to obtain a mixed catalyst;

[0030] mixing the mixed catalyst, polytetrafluoroethylene solution and diluent to obtain a catalyst dispersion;

[0031] After the support skeleton is immersed in the catalyst dispersion, it is pressed with the waterproof breathable membrane to obtain the first air electrode carbon sheet or the second air electrode carbon sheet.

[0032] Preferably, the mass ratio of the carbon powder, graphite, metal oxide and platinum is (68-70):(19-20):(10-15):(2-3);

[0033] The carbon powder is one or more of superconductive carbon powder, activated carbon, carbon black and acetylene black;

[0034] The mass ratio of the mixed catalyst, the polytetrafluoroethylene solution and the diluent is (65-70): (5-6): (20-30), and the mass concentration of the polytetrafluoroethylene solution is 45%-60%.

[0035] The present invention provides a zinc-air battery, comprising a first air electrode carbon sheet, a first positive electrode sheet, a metal zinc paste battery negative electrode, a second positive electrode sheet, a second air electrode carbon sheet and an electrolyte which are sequentially stacked; the electrolyte is filled in the entire cavity of the zinc-air battery; the metal zinc paste battery negative electrode comprises a metal current collector and a first zinc electrode and a second zinc electrode respectively arranged on both sides of the metal current collector; the raw material for preparing the first zinc electrode or the second zinc electrode is metal zinc paste; the raw materials for preparing the metal zinc paste are composed of zinc powder, gel and water; the electrolyte is a semi-solid electrolyte; the The first air electrode carbon sheet and the second air electrode carbon sheet both include a waterproof and breathable membrane and a supporting skeleton with a catalyst on the surface, and the waterproof and breathable membrane is pressed together with the supporting skeleton with a catalyst on the surface; the negative electrode of the metal zinc paste battery cell is wrapped by a shell with a 9-grid window; the negative electrode of the metal zinc paste battery cell is a 9-grid grid structure, and the 9-grid grid structure is consistent with the reinforcement ribs of the 9-grid window of the shell; it also includes a window cover, and the window cover includes a front cover, a rear cover and an upper cover; the window cover is located at the outermost side of the zinc-air battery, and the front cover and the rear cover of the window cover are 8-grid windows. The air electrode sheet in the zinc-air battery of the present invention has a waterproof and breathable function, and the structural design of the zinc-air battery can ensure that more air can enter, so that the contact area between the air electrode sheet and the electrolyte is maximized, and both sides of the negative electrode of the metal zinc paste battery cell can fully react. This makes the zinc-air battery with this structure have excellent discharge performance. When the voltage is maintained at a constant voltage of 0.9V, the specific capacity can reach more than 700Ah / kg, the discharge energy density reaches more than 670Wh / kg, the 24h current is more than 3A, and the 72h current is more than 1A. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of the zinc-air battery of the present invention;

[0037] Figure 2 This is a 3D exploded view of the zinc-air battery of the present invention without the negative electrode of the metal zinc paste battery cell;

[0038] Figure 3 This is a schematic diagram of the position structure of the side steps and positioning posts in the housing of the zinc-air battery of the present invention;

[0039] Figure 4 This is a schematic diagram of the position structure of the sunken step in the shell of the zinc-air battery of the present invention;

[0040] Figure 5 This is a partial cross-sectional structural diagram of the zinc-air battery of the present invention (including the front cover, the first air electrode carbon sheet and the first positive electrode sheet);

[0041] Figure 6This is the discharge voltage-current specific energy capacity curve of the zinc-air battery described in Example 1.

[0042] Among them, 1 is the first air electrode carbon sheet, 2 is the first positive electrode sheet, 3 is the first zinc electrode, 4 is the negative electrode of the metal zinc paste battery cell, 5 is the second zinc electrode, 6 is the second positive electrode sheet, 7 is the second air electrode carbon sheet, 8 is the electrolyte, 9 is the upper cover, 10 is the front cover including the first air electrode carbon sheet, 11 is the shell package with 9 grid windows, 12 is the back cover including the second air electrode carbon sheet, 13 is the side step, 14 is the battery cell negative electrode positioning column, and 15 is the sunken step. DETAILED DESCRIPTION

[0043] The present invention provides a zinc-air battery, comprising a first air electrode carbon sheet, a first positive electrode sheet, a metal zinc paste battery negative electrode, a second positive electrode sheet, a second air electrode carbon sheet and an electrolyte, which are arranged in sequence;

[0044] The electrolyte is filled in the entire cavity of the zinc-air battery (eg Figure 1 shown);

[0045] The negative electrode of the metal zinc paste battery cell includes a metal current collector and a first zinc electrode and a second zinc electrode (such as Figure 1 shown);

[0046] The raw material for preparing the first zinc electrode or the second zinc electrode is metal zinc paste; the raw materials for preparing the metal zinc paste are composed of zinc powder, gel and water;

[0047] The electrolyte is a semi-solid electrolyte;

[0048] The first air electrode carbon sheet and the second air electrode carbon sheet each include a waterproof breathable membrane and a support frame with a catalyst on the surface, and the waterproof breathable membrane and the support frame with the catalyst on the surface are press-fitted;

[0049] The negative electrode of the metal zinc paste battery cell is wrapped by a shell with 9 grid windows (such as Figure 2 shown);

[0050] The negative electrode of the metal zinc paste battery cell has a 9-grid structure, and the 9-grid structure is consistent with the reinforcement ribs of the 9-grid window openings of the shell;

[0051] It also includes a window cover, which includes a front cover, a back cover and an upper cover; the window cover is located at the outermost side of the zinc-air battery, and the front cover and the back cover of the window cover are 8-grid windows (such as Figure 2 shown).

[0052] In the present invention, the 9-grid structure can greatly increase the contact surface between the electrolyte and the catalyst in the air electrode carbon sheet. The 8-grid window opening can greatly increase the air inlet surface.

[0053] In the present invention, the metal zinc paste battery cell negative electrode preferably includes two tabs, and the tabs are not enclosed by the housing with the nine-grid window openings and extend to the outside of the zinc-air battery. In the present invention, the role of the tabs is to facilitate the series and parallel connection of battery cells.

[0054] In the present invention, the inner side section of the shell is preferably provided with side steps and positioning posts (such as Figure 3 The outer side of the shell is preferably provided with a sunken step (as shown) for placing the first positive electrode sheet and the second positive electrode sheet Figure 4 In the present invention, the sinking height of the sunken step is preferably 2 mm. The sunken step is also preferably provided with a sealing silicone pad.

[0055] In the present invention, the first positive electrode sheet and the second positive electrode sheet preferably each include two tabs, and the tabs extend to the outside of the zinc-air battery.

[0056] In the present invention, the zinc-air battery preferably has a rectangular parallelepiped structure.

[0057] In the present invention, the method for preparing the negative electrode of the metal zinc paste battery cell comprises the following steps:

[0058] Mix zinc powder, gel and water to make zinc paste;

[0059] The zinc paste is coated on both sides of the metal current collector to obtain the metal zinc paste battery negative electrode.

[0060] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art.

[0061] The invention mixes zinc powder, gel and water to obtain zinc paste.

[0062] In the present invention, the mass ratio of the zinc powder, gel and water is preferably 30:(1-1.2):(5-6), more preferably 30:(1-1.1):5, and most preferably 30:1:5.

[0063] In the present invention, the gel preferably comprises one or more of food starch glue, polyacrylamide, polyvinyl acetate, sodium carboxymethyl cellulose, and polyurethane. When the gel comprises two or more of the aforementioned materials, the present invention does not impose any particular restrictions on the ratio of the aforementioned materials; they may be mixed in any ratio. In the present invention, the water is preferably deionized water.

[0064] The present invention does not have any special limitation on the mixing process, and the mixing process may be carried out using a process well known to those skilled in the art.

[0065] After obtaining the zinc paste, the present invention applies the zinc paste on both sides of the metal current collector to obtain the negative electrode of the metal zinc paste battery.

[0066] In the present invention, the metal current collector is preferably made of 304 stainless steel sheet. In the present invention, the metal current collector preferably includes two tabs.

[0067] The present invention does not have any special limitation on the coating process. It can be carried out using a process well known to those skilled in the art and ensuring that the tabs in the metal current collector are not coated during the coating.

[0068] In the present invention, the coating thickness is preferably 1 to 2 mm, more preferably 1 to 1.5 mm, and most preferably 1.5 mm.

[0069] After the coating is completed, the present invention further preferably includes drying, wherein the drying temperature is preferably 70° C. and the drying time is preferably 2 hours. In the present invention, the drying is preferably carried out in an oven.

[0070] In the present invention, the first positive electrode sheet and the second positive electrode sheet are preferably 304 stainless steel sheets, which are cut into 9-square grids using laser, and the 9-square grids are consistent with the shell, leaving two tabs.

[0071] In the present invention, the method for preparing the first air electrode carbon sheet and the second air electrode carbon sheet comprises the following steps:

[0072] mixing carbon powder, graphite, metal oxide and platinum to obtain a mixed catalyst;

[0073] mixing the mixed catalyst, polytetrafluoroethylene solution and diluent to obtain a catalyst dispersion;

[0074] After the support skeleton is immersed in the catalyst dispersion, it is pressed with the waterproof breathable membrane to obtain the first air electrode carbon sheet and the second air electrode carbon sheet.

[0075] The present invention mixes carbon powder, graphite, metal oxide and platinum to obtain a mixed catalyst.

[0076] In the present invention, the mass ratio of the carbon powder, graphite, metal oxide and platinum is preferably (68-70):(19-20):(10-15):(2-3), more preferably (68-70):19:(10-12):3, and most preferably 68:19:10:3.

[0077] In the present invention, the carbon powder is preferably one or more of superconducting carbon powder, activated carbon, carbon black and acetylene black. When the carbon powder is two or more of the above specific selections, the present invention has no special restrictions on the ratio of the above specific substances, and they can be mixed in any ratio.

[0078] In the present invention, the metal oxide preferably includes one or more of manganese dioxide, copper oxide, silver oxide and cobalt oxide. When the metal oxide is two or more of the above-mentioned specific selections, the present invention has no special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0079] The present invention does not have any special limitation on the mixing process, and the mixing process may be carried out using a process well known to those skilled in the art.

[0080] After obtaining the mixed catalyst, the present invention mixes the mixed catalyst, polytetrafluoroethylene solution and diluent to obtain a catalyst dispersion.

[0081] In the present invention, the concentration of the polytetrafluoroethylene solution is preferably 45% to 60%, more preferably 50% to 60%, and most preferably 60%.

[0082] In the present invention, the diluent is preferably ethanol and / or ethyl acetate. When the diluent is ethanol and ethyl acetate, the present invention has no special limitation on the ratio of the ethanol and ethyl acetate, and they can be mixed in any ratio.

[0083] In the present invention, the mass ratio of the mixed catalyst, polytetrafluoroethylene solution and diluent is preferably (65-70): (5-6): (20-30), more preferably (65-68): (5.5-6) ​​(24-26), and most preferably 70:5.2:24.8.

[0084] In the present invention, the mixing is preferably carried out under stirring conditions, and the stirring speed is preferably 300-500 r / min, more preferably 450-500 r / min, and most preferably 500 r / min; the stirring time is preferably 10-30 min, more preferably 20-30 min, and most preferably 30 min.

[0085] After obtaining the catalyst dispersion, the present invention immerses the support frame in the catalyst dispersion and then presses the support frame with the waterproof breathable membrane to obtain the first air electrode carbon sheet and the second air electrode carbon sheet.

[0086] In the present invention, the support skeleton is preferably nickel foam or stainless steel mesh; the thickness of the nickel foam is preferably 2.5 mm, the pore size of the nickel foam is preferably 75 ppi, the surface density is preferably 480 g, and the thickness is preferably 2.5 mm; the thickness of the stainless steel mesh is preferably 1 mm.

[0087] Prior to the soaking, the present invention further preferably includes sequentially cleaning and drying the support frame. In the present invention, the cleaning is preferably performed using an organic solvent, preferably ethanol. The present invention does not have any particular limitations on the drying process, and the drying process may be performed using a process well known to those skilled in the art.

[0088] The present invention has no special limitation on the soaking process, and a process well known to those skilled in the art can be used to soak for 15 minutes.

[0089] After the soaking is completed, the present invention further preferably includes drying. The present invention does not have any special limitation on the drying process, and the process well known to those skilled in the art can be used.

[0090] In the present invention, the waterproof and breathable membrane is preferably a polytetrafluoroethylene membrane.

[0091] In the present invention, the pressing pressure is preferably 1-4 MPa, more preferably 1-2 MPa, and most preferably 1 MPa.

[0092] Preferably, the method for preparing the semi-solid electrolyte comprises the following steps:

[0093] Mixing potassium hydroxide, water and gel powder and allowing to stand to obtain the semi-solid electrolyte;

[0094] The mass ratio of the potassium hydroxide, water and gel powder is 345:1000:3.

[0095] In the present invention, the purity of the potassium hydroxide is preferably 95%. In the present invention, the water is preferably deionized water. In the present invention, the gel powder preferably includes one or more of silicon dioxide, a water-absorbing resin (SAP), agar, potassium alginate, sodium alginate, polyacrylamide, and a dispersant. When the gel powder comprises two or more of the above-mentioned specific selections, the present invention does not have any particular restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0096] In the present invention, the mixing is preferably carried out under stirring conditions, the stirring speed is preferably 1000-1500 rpm, more preferably 1200-1500 rpm, most preferably 1500 rpm, and the stirring time is preferably ≥45 min.

[0097] In the present invention, the standing time is preferably 24 hours.

[0098] In the present invention, the preparation method of the zinc-air battery preferably comprises the following steps:

[0099] Take two air electrode carbon sheets (respectively serving as the first air electrode carbon sheet and the second air electrode carbon sheet), with the waterproof and breathable membranes of the air electrode carbon sheets facing outward, and glue the air electrode carbon sheets to the front cover and the back cover (8-grid window cover) of the zinc-air battery with glue, and dry them in the shade for 1 hour;

[0100] Take two positive electrode sheets (serving as the first positive electrode sheet and the second positive electrode sheet, respectively) and two sealing gaskets and glue them to the front and back outer sides of the housing (9-grid structure) of the zinc-air battery, and dry them in the shade for 1 hour.

[0101] The negative electrode of the metal zinc paste battery cell is placed into the housing of the zinc-air battery and fixed in the slot position to obtain a housing with a positive electrode and a negative electrode;

[0102] The zinc-air battery is obtained by sequentially assembling a front cover with an air electrode carbon sheet, a shell with a positive electrode and a negative electrode, and a rear cover with an air electrode carbon sheet, injecting electrolyte, and covering with an upper cover.

[0103] The zinc-air battery provided by the present invention is described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0104] Example 1

[0105] The zinc-air battery structure (rectangular structure) includes: a first air electrode carbon sheet, a first positive electrode sheet (type 304 stainless steel), a metal zinc paste battery negative electrode, a second positive electrode sheet (type 304 stainless steel), a second air electrode carbon sheet and an electrolyte arranged in sequence; the electrolyte is filled in the entire cavity of the zinc-air battery (such as Figure 1 The negative electrode of the metal zinc paste battery cell includes a metal current collector and a first zinc electrode and a second zinc electrode (as shown in FIG. Figure 1 As shown); the raw material for preparing the first zinc electrode or the second zinc electrode is metal zinc paste; the raw material for preparing the metal zinc paste is composed of zinc powder, gel and water; the electrolyte is a semi-solid electrolyte; the first air electrode carbon sheet and the second air electrode carbon sheet both include a waterproof breathable membrane and a support skeleton containing a catalyst on the surface, and the waterproof breathable membrane and the support skeleton containing a catalyst on the surface are pressed together; the negative electrode of the metal zinc paste battery cell is wrapped by a shell with 9 grid windows (as shown Figure 2As shown); the negative electrode of the metal zinc paste battery cell is a 9-grid grid structure, and the 9-grid grid structure is consistent with the reinforcement ribs of the 9-grid window opening of the shell; it also includes a window cover, the window cover includes a front cover, a back cover and an upper cover; the window cover is located at the outermost side of the zinc-air battery, and the front cover and the back cover of the window cover are 8-grid windows (as shown Figure 2 As shown); the negative electrode of the metal zinc paste battery cell includes two tabs, and the tabs are not wrapped by the shell with 9 grid windows and extend to the outside of the zinc-air battery; the inner section of the shell is provided with side steps and positioning columns (as shown) for fixing the negative electrode of the metal zinc paste battery cell Figure 3 The outer side of the shell is provided with a sunken step (as shown) for placing the first positive electrode sheet and the second positive electrode sheet Figure 4 The sinking height of the step is 2 mm. A sealing silicone pad is also placed on the step. The first positive electrode sheet and the second positive electrode sheet each include two tabs, and the tabs extend to the outside of the zinc-air battery.

[0106] Preparation method of the first air electrode carbon sheet and the second air electrode carbon sheet: 75ppi 2.5mm thick nickel foam is cleaned with an organic solvent and dried for use; 68wt% superconducting carbon powder, 19wt% graphite, 10wt% manganese dioxide and 3wt% platinum are mixed and stirred for 5 minutes to obtain a catalyst mixture; the catalyst mixture, a polytetrafluoroethylene solution with a mass concentration of 60% and a diluent (ethanol and ethyl acetate with a mass ratio of 1:1) are stirred at a speed of 500r / min for 10 minutes according to a mass ratio of 70:5.2:24.8 to obtain a mixed solution; the pretreated nickel foam is immersed in the mixed solution for 15 minutes, lifted and dried for 10 minutes, and then pressed with a waterproof and breathable membrane (polytetrafluoroethylene membrane) at a pressure of 1MPa to obtain the first air electrode carbon sheet and the second air electrode carbon sheet;

[0107] Preparation method of the metal zinc paste battery negative electrode: According to the mass ratio of 30:1:5, metal zinc powder, gel (type is polyacrylamide) and deionized water are mixed to obtain zinc paste; 130g of zinc paste is evenly coated on the front and back sides of the metal current collector (type is 304 stainless steel sheet) with a thickness of 1.5mm, without coating the two electrode tabs of the metal current collector, and then placed in a 70° oven for 2h to obtain the metal zinc paste battery negative electrode;

[0108] Preparation method of the semi-solid electrolyte: 345 g of 95% pure potassium hydroxide, 1 L of deionized water, and 3 g of gel (agar) are placed in a magnetic stirrer and stirred at 1500 rpm for 45 minutes, then poured into a glass bottle and allowed to stand for 24 hours to obtain the semi-solid electrolyte;

[0109] The preparation process of the zinc-air battery comprises the following steps: taking two air electrode carbon sheets (respectively serving as the first air electrode carbon sheet and the second air electrode carbon sheet), with the waterproof and breathable membranes of the air electrode carbon sheets facing outward, and gluing the air electrode carbon sheets to the front cover and the back cover (8-grid window cover) of the zinc-air battery, and drying them in the shade for 1 hour for later use; taking two positive electrode sheets (respectively serving as the first positive electrode sheet and the second positive electrode sheet) and two sealing gaskets, gluing them to the front and back outer sides of the zinc-air battery shell (9-grid structure), and drying them in the shade for 1 hour for later use; placing the negative electrode of the metal zinc paste battery cell into the zinc-air battery shell and fixing it in a slot position to obtain a shell with a positive electrode and a negative electrode; assembling the front cover with the air electrode carbon sheet, the shell with the positive electrode and the negative electrode, and the back cover with the air electrode carbon sheet in sequence, injecting electrolyte, and covering the upper cover to obtain the zinc-air battery.

[0110] Figure 6 The discharge voltage-current-specific energy capacity curve of the zinc-air battery is tested using a newwear tester at room temperature at a constant voltage of 0.9V to observe the changes in current and specific capacity. Figure 6 As can be seen, the voltage curve remains constant at 0.9V, while the current curve slowly rises at first, reaching a maximum of 5A. After reaching the peak, it very slowly decreases to 0.15A before the test stops. The entire test lasts 150 hours, and the specific capacity is 720mAh / g.

[0111] 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 modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A zinc-air battery, characterized in that: It includes a first air electrode carbon sheet, a first positive electrode sheet, a metal zinc paste battery negative electrode, a second positive electrode sheet, a second air electrode carbon sheet and an electrolyte which are arranged in sequence; The electrolyte is filled in the entire cavity of the zinc-air battery; The negative electrode of the metal zinc paste battery cell includes a metal current collector and a first zinc electrode and a second zinc electrode respectively arranged on both sides of the metal current collector; The raw material for preparing the first zinc electrode or the second zinc electrode is metal zinc paste; the raw materials for preparing the metal zinc paste are composed of zinc powder, gel and water; The electrolyte is a semi-solid electrolyte; The first air electrode carbon sheet and the second air electrode carbon sheet each include a waterproof breathable membrane and a support frame with a catalyst on the surface, and the waterproof breathable membrane and the support frame with the catalyst on the surface are press-fitted; The negative electrode of the metal zinc paste battery cell is wrapped by a shell with 9 grid windows; The negative electrode of the metal zinc paste battery cell has a 9-grid structure, and the 9-grid structure is consistent with the reinforcement ribs of the 9-grid window openings of the shell; Also includes a window cover, the window cover includes a front cover, a rear cover and an upper cover; the window cover is located at the outermost side of the zinc-air battery, and the front cover and the rear cover of the window cover are 8-grid windows; The inner section of the shell is provided with side steps and positioning posts for fixing the negative electrode of the metal zinc paste battery cell; The outer side of the housing is provided with a sunken step for placing the first positive electrode sheet and the second positive electrode sheet; The method for preparing the negative electrode of the metal zinc paste battery cell comprises the following steps: Mix zinc powder, gel and water to make zinc paste; Applying the zinc paste on both sides of the metal current collector to obtain the negative electrode of the metal zinc paste battery; The method for preparing the first air electrode carbon sheet or the second air electrode carbon sheet comprises the following steps: mixing carbon powder, graphite, metal oxide and platinum to obtain a mixed catalyst; mixing the mixed catalyst, polytetrafluoroethylene solution and diluent to obtain a catalyst dispersion; After the support skeleton is immersed in the catalyst dispersion, it is pressed with the waterproof breathable membrane to obtain the first air electrode carbon sheet or the second air electrode carbon sheet.

2. The zinc-air battery according to claim 1, wherein The negative electrode of the metal zinc paste battery cell includes two tabs, and the tabs are not wrapped by the shell with 9-grid windows and extend to the outside of the zinc-air battery.

3. The zinc-air battery according to claim 1, wherein The first positive electrode sheet and the second positive electrode sheet each include two tabs, and the tabs extend to the outside of the zinc-air battery.

4. The zinc-air battery according to claim 1, wherein The mass ratio of the zinc powder, gel and water is 30: (1-1.2): (5-6); The gel comprises one or more of food starch glue, polyacrylamide, polyvinyl acetate, sodium carboxymethyl cellulose and polyurethane.

5. The zinc-air battery according to claim 1, wherein The preparation method of the semi-solid electrolyte comprises the following steps: mixing potassium hydroxide, water and gel powder, and allowing the mixture to stand to obtain the semi-solid electrolyte; The mass ratio of the potassium hydroxide, water and gel powder is 345:1000:

3.

6. The zinc-air battery according to claim 5, wherein The gel powder comprises one or more of silicon dioxide, water-absorbing resin SAP, agar, potassium alginate, sodium alginate, polyacrylamide and a dispersant.

7. The zinc-air battery according to claim 1, wherein The mass ratio of the carbon powder, graphite, metal oxide and platinum is (68-70): (19-20): (10-15): (2-3); The carbon powder is one or more of superconductive carbon powder, activated carbon, carbon black and acetylene black; The mass ratio of the mixed catalyst, polytetrafluoroethylene solution and diluent is (65-70): (5-6): (20-30), and the mass concentration of the polytetrafluoroethylene solution is 45%-60%.

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