Solid-state electrolyte membrane, method for preparing the same, and use thereof

Abstract

The application discloses a solid-state electrolyte film and a preparation method and application thereof. The solid-state electrolyte film comprises a base and a solid solution salt. The base is an alginate. The solid solution salt is at least one selected from sodium salt, lithium salt and potassium salt. The solid-state electrolyte has excellent electrochemical performance, and has a very large application prospect as an anode electrolyte of a solid-liquid high-voltage magnesium air battery. Meanwhile, the solid-state electrolyte has a simple and controllable preparation process, and a simple device, and is a method easy to mass produce.

Description

Technical Field

[0001] This application relates to a solid electrolyte membrane, its preparation method and application, belonging to the field of electrolyte preparation and electrochemical technology. Background Technology

[0002] Magnesium-air batteries use oxygen from the air as the positive electrode active material and magnesium metal and its alloys as the negative electrode. They feature simple structure, inherent safety, low cost, and good discharge performance (theoretical voltage of 3.1V and energy density of 6.8 kWh / kg). -1 It has the advantages of [missing information - likely related to energy efficiency]. It has been used as an emergency backup power source and is expected to be applied in electric vehicles, portable power supplies, flexible wearable power supplies, etc. Magnesium anodes have a low density (1.74 g / cm³). -3 High theoretical capacity (2.2 Ah g) -1 Magnesium has the characteristics of a negative potential (2.37V vs. SHE). However, magnesium is an active metal and is easily corroded in commonly used NaCl aqueous electrolytes, which greatly reduces the utilization rate of magnesium anodes and leads to significant mass and energy losses.

[0003] Currently, alloying magnesium metal and adding corrosion inhibitors to aqueous solutions to passivate the magnesium anode surface are common methods to reduce hydrogen evolution corrosion (HEC) on magnesium anodes. However, the utilization rate of magnesium anodes remains low. The accumulation of corrosion product layers and passivation surface films leads to a decrease in battery voltage because they hinder direct contact between the magnesium anode surface and the electrolyte. Furthermore, most researchers focus on non-aqueous electrolyte systems, such as organic electrolytes and ionic liquid electrolytes. Examples include Grignard reagents, magnesium aluminum chloride complexes (MACC), and organic borate / carbonate or non-reducing ether solvents such as tetrahydrofuran (THF), dimethyl ether (DME), and glycine. Some of these strategies have successfully limited the formation of passivation films, while others generate SEI films to achieve reversible magnesium dissolution and deposition. Nevertheless, organic magnesium batteries often suffer from electrochemical oxidation instability and poor conductivity. Summary of the Invention

[0004] The purpose of this application is to avoid the problem of low utilization rate of magnesium anodes and improve the specific energy of batteries by providing a solid electrolyte.

[0005] One aspect of this application provides a solid electrolyte membrane, the solid electrolyte membrane comprising a matrix and a solid solution salt;

[0006] The matrix is ​​alginate;

[0007] The solid salt is selected from at least one of sodium salt, lithium salt, and potassium salt.

[0008] Optionally, the alginate is selected from at least one of sodium alginate, potassium alginate, and magnesium alginate;

[0009] The sodium salt is selected from at least one of sodium chloride, sodium formate, sodium sulfate, sodium acetate, and sodium fluoroborate;

[0010] The lithium salt is selected from at least one of lithium chloride, lithium sulfate, lithium acetate, and lithium formate;

[0011] The potassium salt is selected from at least one of potassium acetate, potassium chloride, potassium sulfate, and potassium fluoroborate.

[0012] Optionally, the thickness of the solid electrolyte membrane is 20 nm to 500 nm.

[0013] Optionally, the thickness of the solid electrolyte membrane is independently selected from any value among 20nm, 50nm, 100nm, 245nm, 350nm, 400nm, and 500nm, or any range between any two of the above.

[0014] Optionally, in the solid electrolyte membrane, the mass ratio of the matrix to the solid solution salt is 1:0.5 to 1:6.

[0015] Optionally, the mass ratio of the matrix to the solid salt is independently selected from any value among 1:0.5, 1:0.8, 1:1, 1:2, 1:3.5, 1:6 or any range between any two of the above.

[0016] Optionally, the sodium salt, lithium salt, and potassium salt can be in any ratio.

[0017] Another aspect of this application provides a method for preparing the above-mentioned solid electrolyte membrane, the method comprising:

[0018] The solid electrolyte membrane is obtained by coating and drying an aqueous solution containing alginate and solid solution salt.

[0019] Optionally, in the aqueous solution, the mass ratio of alginate to solid salt is 1:0.5 to 1:6;

[0020] The total mass ratio of alginate and dissolved salt to water is 1:0.5 to 1:5;

[0021] Optionally, the drying temperature is 60–90°C;

[0022] The drying time is 6 to 12 hours.

[0023] Optionally, the mass ratio of the alginate to the solid salt is independently selected from any value among 1:0.5, 1:0.8, 1:1, 1:2, 1:3.5, 1:6 or any range between any two of the above.

[0024] Optionally, the mass ratio of the total mass of the alginate and the dissolved salt to the mass of water is independently selected from any value among 1:0.5, 1:1, 1:5, or any range between any two of the above points.

[0025] Optionally, the drying temperature is independently selected from any value among 60°C, 70°C, 80°C, and 90°C, or any range between any two of the above.

[0026] Optionally, the drying time is independently selected from any value among 6h, 8h, 10h, and 12h, or any range between any two of the above.

[0027] In another aspect of this application, a solid-liquid high-voltage magnesium-air battery is provided, the solid-liquid high-voltage magnesium-air battery comprising a magnesium anode, a solid anode electrolyte and a cathode arranged sequentially, wherein a cathode electrolyte is filled between the cathode and the solid anode electrolyte.

[0028] The solid anode electrolyte is selected from the solid electrolyte membrane described above or the solid electrolyte membrane obtained by the preparation method described above.

[0029] Optionally, the cathode is selected from at least one of a porous air electrode supported on a MnO2 / C catalyst, a porous air electrode supported on an Ag / MnO2 catalyst, and a porous air electrode supported on a MnO2 / carbon nanotube.

[0030] Optionally, the magnesium anode is pure magnesium or a magnesium alloy.

[0031] Optionally, the magnesium alloy is selected from at least one of AZ61 magnesium alloy, AZ31 magnesium alloy, and AZ91 magnesium alloy.

[0032] Optionally, the cathode electrolyte is an organic acid.

[0033] Optionally, the organic acid is selected from at least one of formic acid, acetic acid, propionic acid, and butyric acid.

[0034] Optionally, the operating voltage of the solid-liquid high-voltage magnesium-air battery is 0.1–2.8V;

[0035] The power density of the solid-liquid high-voltage magnesium-air battery is 0.2 mW / cm². -2 ~5.9mW cm -2 .

[0036] Optionally, the operating voltage of the solid-liquid high-voltage magnesium-air battery is independently selected from any value among 0.1V, 0.5V, 1.0V, 1.5V, 1.8V, 2.2V, 2.5V, and 2.8V, or any range between any two of the above values.

[0037] Optionally, the power density of the solid-liquid high-voltage magnesium-air battery is independently selected from 0.2 mW / cm².-2 0.5mW cm -2 1.4mW cm -2 2.2mW cm -2 3.6mW cm -2 4.5mW cm -2 5.9mW cm -2 Any value in or any range between any two of the above points.

[0038] This invention provides a solid-liquid high-voltage magnesium-air battery, using acetic acid as the cathode electrolyte, sodium alginate / sodium chloride solid electrolyte as the anode electrolyte, AZ61 alloy as the anode, and a porous air electrode with MnO2 / C as the catalyst as the cathode. In this invention, by using acetic acid as the cathode electrolyte, the theoretical discharge voltage of the battery is 0.6V higher than that using neutral or alkaline electrolyte systems, which can improve the battery's discharge specific energy. In this invention, by using a solid electrolyte as the anode electrolyte, the self-corrosion of the magnesium anode by hydrogen evolution can be reduced, and the anode utilization rate can be improved, further increasing the battery's specific energy. At 0.1 mA cm⁻¹ -2 At the specified current density, the anode utilization rate reached 61.5%, the open-circuit voltage of the battery reached 2.587V, and the average discharge voltage reached 2.2V. However, in a 10% NaCl single electrolyte, the anode utilization rate was only 9.6%, the open-circuit voltage was only 1.892V, and the discharge voltage was only 1.65V. At 0.1mA cm⁻¹ -2 At the specified current density, the discharge specific energy of the solid-liquid high-voltage magnesium-air battery reaches 2976.56 Wh kg. -1 However, in a 10% NaCl single electrolyte solution, the battery's discharge specific energy is only 350.6 Wh / kg. -1 The excellent electrochemical performance indicates that the solid electrolyte and solid-liquid high-voltage magnesium-air battery of this invention have great application prospects. Furthermore, the preparation process of this solid electrolyte and solid-liquid high-voltage magnesium-air battery is simple and controllable, requiring only basic equipment, making it an easy method for large-scale production.

[0039] The beneficial effects that this application can produce include:

[0040] 1) The raw materials used in this invention are inexpensive materials such as alginate, sodium salt, or potassium salt. The materials are widely available, green and safe, and low in cost.

[0041] 2) The preparation method of this invention is simple and can be mass-produced.

[0042] 3) When the solid electrolyte obtained by this invention is used as the anode electrolyte of a solid-liquid high-voltage magnesium-air battery, it can effectively improve the anode utilization rate.

[0043] 4) The excellent electrochemical performance of the solid electrolyte in this application indicates that it has great application potential as the anode electrolyte of solid-liquid high-voltage magnesium-air battery. Attached Figure Description

[0044] Figure 1 The images shown are physical photos and SEM images of the solid electrolyte obtained in Example 1 of this application.

[0045] Figure 2 The graphs show the discharge curves of a solid-liquid high-voltage magnesium-air battery with a solid anode electrolyte obtained in Example 1 of this application, and the battery in a 10% NaCl single electrolyte solution.

[0046] Figure 3 The graph shows the anode utilization rate of the solid electrolyte obtained in Example 1 of this application in a solid-liquid high-voltage magnesium-air battery with solid anode electrolyte and in a magnesium-air battery with 10% NaCl single electrolyte.

[0047] Figure 4 The diagram shows the open-circuit voltage of a solid-liquid high-voltage magnesium-air battery with a solid anode electrolyte obtained in Example 1 of this application, and a magnesium-air battery in a 10% NaCl single electrolyte solution. Detailed Implementation

[0048] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0049] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0050] AZ61 was scanned using a JSM-7800F scanning electron microscope.

[0051] Electrochemical performance was tested using the Xinwei Battery Testing System.

[0052] This invention relates to a method for preparing an alginate / solid salt solid electrolyte, comprising the following steps:

[0053] Weigh out the appropriate proportions of sodium alginate / potassium alginate / magnesium alginate, NaCl / Li2SO4 / K2(COOH)2 and deionized water, stir well, and then coat it onto a glass plate. Dry it at 60℃ for 6 hours before use.

[0054] The mass ratio of alginate to solid salt is 1:0.5 to 1:6, the mass ratio of all salts to deionized water is 1:0.5 to 1:5, and the thickness of the solid electrolyte is 20 nm to 500 nm.

[0055] The solid electrolyte prepared in the above steps was used as the anolyte. An AZ61 anode and an air electrode with MnO2 / C as the catalyst were used as the cathode, and an organic acid was used as the cathode electrolyte to assemble a solid-liquid high-voltage magnesium-air battery. The prepared battery was then subjected to electrochemical performance testing using a Newway battery testing system.

[0056] Preparation Example

[0057] The preparation method of the air electrode using MnO2 / C supported catalyst is as follows: The MnO2 / C catalyst is prepared by a hydrothermal method. First, 3g of KMnO4 is dissolved in 60mL of deionized water, 6mL of anhydrous ethanol is added dropwise, followed by 0.8g of activated carbon. After stirring evenly, the mixture is transferred to a 100mL reaction vessel and kept at 130℃ for 24h. Then, it is allowed to cool naturally to room temperature. The brown precipitate is filtered, washed, and dried at 80℃ for 10h. Next, 1g of the prepared MnO2 / C catalyst is mixed with polytetrafluoroethylene (PTFE) emulsion (60% mass concentration) at a mass ratio of 7:3, and 1mL of deionized water is added and stirred for 1h. The mixed slurry is then brushed onto nickel foam with a catalyst loading of 10mg / cm³. -2 Subsequently, nickel foam coated with MnO2 / C catalyst was laminated together with a commercial diffusion layer to finally prepare a porous air cathode.

[0058] Example 1

[0059] Weigh 1g sodium alginate, 1g NaCl and 6g deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0060] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0061] Figure 1 The image shows a physical sample of the prepared solid electrolyte. (From...) Figure 1 As can be seen, the prepared solid electrolyte has a uniform and dense texture, with NaCl dissolved in the sodium alginate matrix. During discharge, the AZ61 magnesium alloy anode reaction equation is as follows: The prepared solid electrolyte conducts Na between the positive and negative electrodes. + Ions connect the circuit and act as a diaphragm to separate the positive and negative electrodes and prevent them from directly contacting each other and short-circuiting.

[0062] Figure 2 For 0.1mA cm -2The discharge curves of a solid-liquid high-voltage magnesium-air battery using acetic acid as the cathode electrolyte and sodium alginate / sodium chloride as the solid anode electrolyte, and a battery in a 10% NaCl single electrolyte, are shown in Figure 2. It can be clearly seen from Figure 2 that at a current density of 0.1 mA cm⁻¹, the discharge curves of the battery are shown in Figure 2. -2 At a current density of 10%, the average discharge voltage of a solid-liquid high-voltage magnesium-air battery can reach 2.2V, while the average discharge voltage of the battery in a 10% NaCl single electrolyte is only 1.65V.

[0063] Figure 3 For 0.1mA cm -2 The graph shows the anode utilization rates of a solid-liquid high-voltage magnesium-air cell using acetic acid as the cathode electrolyte and sodium alginate / sodium chloride as the solid anode electrolyte at a given current density, and a magnesium-air cell in a 10% NaCl single electrolyte. Figure 3 As can be seen, at 0.1 mA cm -2 At a current density of [value missing], the anode utilization rate of the solid-liquid high-voltage magnesium-air battery can reach 61.5%, and the anode discharge specific energy is 2976.56 Wh / kg. -1 However, in a magnesium-air battery with a 10% NaCl single electrolyte, the anode utilization rate is only 9.6%, and the anode utilization rate is only 350.6 Wh / kg. -1 .

[0064] Figure 4 Open-circuit voltage diagrams are shown for a solid-liquid high-voltage magnesium-air cell using acetic acid as the cathode electrolyte and sodium alginate / sodium chloride as the solid anode electrolyte, and for a magnesium-air cell in a 10% NaCl single electrolyte. From... Figure 4 As can be seen, the open-circuit voltage of the solid-liquid high-voltage magnesium-air battery can reach 2.587V, while the open-circuit voltage of the magnesium-air battery in 10% NaCl single electrolyte is only 1.892V.

[0065] Example 2

[0066] Weigh 1g of potassium alginate, 1g of NaCl and 6g of deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0067] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0068] Example 2 uses essentially the same method as Example 1, except that the alginate used in the solid electrolyte is replaced with potassium alginate instead of sodium alginate. The prepared solid electrolyte is similar to that of Example 1, exhibiting the same uniform and dense texture, with NaCl dissolved in the potassium alginate matrix. Electrochemical performance tests show that the assembled battery performance is essentially the same as that of Example 1, with the same anode utilization rate. The open-circuit voltage is 0.05V lower than that of Example 1, and the average discharge voltage is 0.01V lower. This is because the potassium alginate matrix used in the solid electrolyte has similar properties to sodium alginate, except that potassium alginate conducts NaCl more readily than sodium alginate. + Its ionizing ability is slightly weak.

[0069] Example 3

[0070] Weigh 1g sodium alginate, 1g Li2SO4 and 6g deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0071] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0072] Example 3 used essentially the same method as Example 1, except that the solid electrolyte was prepared using Li₂SO₄ instead of NaCl. The prepared solid electrolyte was similar to that of Example 1, exhibiting a uniform and dense texture, with Li₂SO₄ dissolved in the potassium alginate matrix. Electrochemical performance tests showed that the assembled battery performed essentially the same as in Example 1, with the same anode utilization rate. The open-circuit voltage was 0.15V lower than in Example 1, and the average discharge voltage was 0.05V lower. The 0.15V lower open-circuit voltage compared to Example 1 was due to the SO₄²⁻. 2- ion ratio Cl - The ability of ions to destroy the oxide passivation layer on the magnesium anode surface is slightly weaker; the average discharge voltage is only 0.05V lower than in Example 1 due to the Li-conducting solid electrolyte. + Ionizing ability compared to Na + The ion-carrying capacity is slightly stronger, resulting in the battery discharge voltage not decreasing as much as the open-circuit voltage.

[0073] Example 4

[0074] Weigh 1g sodium alginate, 1g NaCl and 6g deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0075] Using the solid electrolyte prepared according to the above steps as the anolyte, propionic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0076] Example 4 used essentially the same method as Example 1, except that the cathode electrolyte was changed from acetic acid to propionic acid. Electrochemical performance tests showed that the assembled battery's performance was essentially the same as in Example 1, with the same anode utilization rate. The open-circuit voltage was 0.08V lower than in Example 1, and the average discharge voltage was 0.12V lower. The 0.08V lower open-circuit voltage is due to the propionic acid ions ionizing H+ more readily than acetic acid ions. + The ionization ability is slightly weaker; the average discharge voltage is 0.12V lower than that of Example 1 because propionic acid has a higher viscosity and slightly lower conductivity than acetic acid, resulting in a greater reduction in battery discharge voltage compared to open circuit voltage.

[0077] Example 5

[0078] Weigh 1g sodium alginate, 1g NaCl and 6g deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 200nm.

[0079] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0080] Example 5 used essentially the same method as Example 1, except that the thickness of the solid electrolyte was changed from 100 nm to 200 nm. Electrochemical performance tests showed that the assembled battery performance was essentially the same as in Example 1, with the same anode utilization rate and open-circuit voltage. The average discharge voltage was 0.02 V lower than in Example 1. This 0.02 V decrease in average discharge voltage was due to the doubling of the solid electrolyte thickness, resulting in increased Na... + The increased ion transport distance leads to greater polarization during battery discharge, resulting in a 0.02V decrease in the average discharge voltage of the battery compared to Example 1.

[0081] Example 6

[0082] Weigh 1g sodium alginate, 1g NaCl and 6g deionized water, stir well and then coat it onto the surface of a glass plate. Dry at 60℃ for 6 hours and then set aside for use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0083] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ31 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0084] Example 6 uses essentially the same method as Example 1, except that the anode is changed from AZ61 to AZ31. Electrochemical performance tests show that the assembled battery performance is basically the same as that of Example 1, with the anode utilization rate only 0.5% lower than that of Example 1, and the open-circuit voltage being the same. The average discharge voltage is 0.03V lower than that of Example 1. This is because the properties of AZ31 alloy and AZ61 alloy are similar, and under the same conditions of cathode, cathodic electrolyte, and solid anode electrolyte, the various discharge performance characteristics of the battery are similar to those of Example 1.

[0085] Comparative Example 1

[0086] Weigh 1g of sodium alginate and 6g of deionized water, stir well, and then coat the mixture onto the surface of a glass plate. Dry at 60℃ for 6 hours before use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0087] Using the solid electrolyte prepared according to the above steps as the anode electrolyte, acetic acid as the cathode electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode, a solid-liquid high-voltage magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0088] Comparative Example 1 used essentially the same method as Example 1, except that the solid electrolyte used was only sodium alginate matrix, without any added solid solution salts. Electrochemical performance tests showed that the assembled battery performance differed significantly from that of Example 1. The anode utilization rate was the same as in Example 1, but the open-circuit voltage was 0.5V lower. The average discharge voltage was 1V lower than in Example 1. The 0.5V lower open-circuit voltage is due to the fact that alginate is much less effective than solid solution salts at damaging the oxide passivation layer on the magnesium anode surface. The 1V lower average discharge voltage is due to the fact that the solid electrolyte, without added solid solution salts, has significantly reduced conductivity, leading to much greater polarization during battery discharge, resulting in a 1V lower average discharge voltage compared to Example 1.

[0089] Comparative Example 2

[0090] Weigh 1g of sodium alginate and 6g of deionized water, stir well, and then coat the mixture onto the surface of a glass plate. Dry at 60℃ for 6 hours before use. Control the thickness of the solid electrolyte membrane to be 100nm.

[0091] Using the solid electrolyte prepared according to the above steps as the electrolyte, the electrode obtained in the preparation example as the cathode, and AZ61 as the anode, a magnesium-air battery was assembled. The prepared battery was then subjected to electrochemical performance testing using the Xinwei Battery Testing System.

[0092] Comparative Example 2 used essentially the same method as Example 1, except that the solid electrolyte used was a single-electrolyte battery. Electrochemical performance tests showed that the assembled battery could not discharge normally. This was because no reaction occurred at the cathode in the prepared solid electrolyte, resulting in the battery's inability to discharge normally.

[0093] Comparative Example 3

[0094] A magnesium-air battery was assembled using acetic acid as the electrolyte, the electrode prepared in the preparation example as the cathode, and AZ61 as the anode. The electrochemical performance of the prepared battery was then tested using a Newway battery testing system.

[0095] Comparative Example 3 used essentially the same method as Example 1, except that the electrolyte used was acetic acid as a single electrolyte. Electrochemical performance tests showed that the anode utilization rate of the assembled battery was only 4.6%. This is because acetic acid accelerates hydrogen evolution corrosion of the magnesium anode, resulting in low anode utilization.

[0096] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A solid electrolyte membrane, characterized in that, The solid electrolyte membrane comprises a matrix and a solid solution salt; The matrix is ​​alginate; The solid salt is selected from at least one of sodium salt, lithium salt, and potassium salt; The solid electrolyte membrane is used in solid-liquid high-voltage magnesium-air batteries; The solid-liquid high-voltage magnesium-air battery includes a magnesium anode, a solid anode electrolyte, and a cathode arranged in sequence, with a cathode electrolyte filling the space between the cathode and the solid anode electrolyte.

2. The solid electrolyte membrane according to claim 1, characterized in that, The alginate is selected from at least one of sodium alginate, potassium alginate, and magnesium alginate; The sodium salt is selected from at least one of sodium chloride, sodium formate, sodium sulfate, sodium acetate, and sodium fluoroborate; The lithium salt is selected from at least one of lithium chloride, lithium sulfate, lithium acetate, and lithium formate; The potassium salt is selected from at least one of potassium acetate, potassium chloride, potassium sulfate, and potassium fluoroborate.

3. The solid electrolyte membrane according to claim 1, characterized in that, The thickness of the solid electrolyte membrane is 20 nm to 500 nm.

4. The solid electrolyte membrane according to claim 1, characterized in that, In the solid electrolyte membrane, the mass ratio of the matrix to the solid salt is 1:0.5 to 1:

6.

5. The solid-state electrolyte film of claim 1, wherein, Its preparation methods include: The solid electrolyte membrane is obtained by coating and drying an aqueous solution containing alginate and solid solution salt.

6. The solid electrolyte membrane according to claim 5, characterized in that, In the aqueous solution, the mass ratio of alginate to solid salt is 1:0.5 to 1:6; The total mass ratio of alginate and dissolved salt to water is 1:0.5 to 1:

5.

7. The solid-state electrolyte film of claim 5, wherein, The drying temperature is 60~90℃; The drying time is 6-12 hours.

8. A solid electrolyte membrane according to claim 1, characterized in that, The cathode is selected from at least one of the following: a porous air electrode supported on MnO2 / C catalyst, a porous air electrode supported on Ag / MnO2 catalyst, and a porous air electrode supported on MnO2 / carbon nanotubes.

9. A solid electrolyte membrane according to claim 1, characterized in that, The cathode electrolyte is an organic acid.

10. A solid electrolyte membrane according to claim 9, characterized in that, The organic acid is selected from at least one of formic acid, acetic acid, propionic acid, and butyric acid.

11. A solid electrolyte membrane according to claim 1, characterized in that, The operating voltage range of the solid-liquid high-voltage magnesium-air battery is 0.1~2.8 V; The power density of the solid-liquid high-voltage magnesium air battery is 0.2 mW cm -2 5.9 mW cm -2 .

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