Zinc-nitrate battery electrolyte and preparation method and application thereof

Abstract

The invention relates to the technical field of batteries, in particular to a zinc-nitrate battery electrolyte and a preparation method and application thereof. The electrolyte comprises electrolyte nitrate, alkali and an alkali metal ion additive; the alkali metal ion additive is cesium hydroxide or potassium hydroxide. By adding the alkali metal ion additive into the electrolyte, on one hand, electrostatic interaction between nitrate ions in the electrolyte and a cathode is adjusted, mass transfer of nitrate is promoted, and the efficiency of electrochemical reduction of nitrate is improved; on the other hand, the interaction of an electrode-solution interface is changed, the damage of a hydrogen bond network in interface water is promoted, the hydrogen precipitation side reaction is inhibited, the electrochemical ammonia production efficiency is promoted, and efficient nitrate wastewater ammonia synthesis and electric energy co-production are realized in a zinc-nitrate battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a zinc-nitrate battery electrolyte, its preparation method, and its application. Background Technology

[0002] Ammonia is a promising carbon-free energy carrier with an energy density as high as 4.3 kWh / kg. -1 This technology is expected to provide significant support for achieving future "dual carbon" goals. Ammonia-based nitrogen fertilizer production plays an irreplaceable role in ensuring the growing demand for food. Currently, ammonia production mainly relies on the Haber-Bosch process for thermochemical synthesis. However, the Haber-Bosch process depends on fossil fuels, consuming 1%-2% of global energy and contributing 1% of global energy-related carbon emissions. Furthermore, the large scale of Haber-Bosch ammonia synthesis plants makes it difficult to adapt to the application needs of distributed renewable energy sources.

[0003] Human activities have gradually exacerbated the nitrate pollution problem, with nitrate concentrations in groundwater reaching as high as 15 mg / L in some areas. -1 The levels of nitrates far exceed the World Health Organization's drinking water standards. Therefore, developing efficient nitrate removal technologies is urgently needed. However, existing treatment methods (including ion exchange, reverse osmosis, electrodialysis, and biological denitrification) generally suffer from bottlenecks such as low efficiency, poor environmental adaptability, and the need for subsequent treatment. Currently, electrocatalytic nitrate reduction to ammonia synthesis is considered a green, efficient, and environmentally friendly method. On the one hand, it can utilize surplus electricity generated from renewable energy sources such as solar, wind, or hydropower; on the other hand, the energy required for the dissociation of N=O in nitrates is only 204 kJ / mol. -1 This is far lower than the 941 kJ / mol required for the dissociation of the N≡N triple bond. -1 It is more energy-efficient than the Haber-Bosch process.

[0004] Currently, the electrochemical nitrate reduction reaction for ammonia synthesis faces three main challenges. First, the reaction involves a complex 8-electron transfer process, and byproducts include NO2. - The reaction involves N2, N2H4, and H2, making selectivity crucial. Secondly, the reaction kinetics are slow; although copper-based catalysts exhibit the highest reaction rates among metal catalysts such as copper (Sustainable Energy & Fuels, 2024, 8, 3925-3932.), nickel (Energy & Environmental Science, 2023, 16, 2991-3001.), and ruthenium (ACS Catalysis, 2024, 14, 12152-12162.), further improvements are needed. Finally, the reaction occurs at the cathode, where NO3... -The charge repulsion between the cathode and the electrode hinders mass transfer, while the competitive adsorption of other ions on the electrode further affects the reaction efficiency (Angew Chem Int Ed, 2024, 63, e202408382.). Summary of the Invention

[0005] The purpose of this invention is to provide a zinc-nitrate battery electrolyte, its preparation method and application. By adding alkali metal ion additives to the electrolyte, the electrostatic repulsion of nitrate ions diffusing into the cathode double layer is alleviated on the cathode side, while improving the selectivity and yield of nitrate reduction to ammonia.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: The first aspect of the present invention provides a zinc-nitrate battery electrolyte, the electrolyte comprising an electrolyte nitrate, an alkali, and an alkali metal ion additive; the alkali metal ion additive is cesium hydroxide or potassium hydroxide.

[0007] Preferably, the electrolyte nitrate is at least one of lithium nitrate, sodium nitrate, potassium nitrate, and cesium nitrate.

[0008] Preferably, the alkali is sodium hydroxide.

[0009] Preferably, the concentration of the alkali metal ion additive in the electrolyte is 0.005~0.02 mol / L. -1 When the additive content is too high, it will inhibit the water required for the electrocatalytic reduction of nitrate to ammonia, thus inhibiting the efficiency of electrochemical reduction of nitrate and resulting in low ammonia production efficiency and output power in zinc-nitrate batteries.

[0010] Preferably, the concentration of the electrolyte nitrate in the electrolyte is 0.01~0.1 mol L. -1 The concentration of the alkali is 0.5~1.5 mol L. -1 .

[0011] Preferably, the molar ratio of the alkali, electrolyte nitrate, and alkali metal ion additive is 50:1:(0.25~1).

[0012] A second aspect of the present invention provides a method for preparing the above-mentioned electrolyte, wherein an alkali metal ion additive is added to an alkaline solution containing electrolyte nitrate, and the solution is stirred at room temperature until homogeneous to obtain the electrolyte.

[0013] A third aspect of the present invention provides a zinc-nitrate battery, the battery comprising a positive electrode, a negative electrode and a separator, wherein a positive electrolyte is filled in the cavity between the positive electrode and the separator, and a negative electrolyte is filled in the cavity between the negative electrode and the separator, wherein the negative electrolyte is the electrolyte described above.

[0014] Preferably, the positive electrode is made of at least one of copper foam or copper sheet.

[0015] Preferably, the negative electrode material is at least one of zinc foam or zinc sheet.

[0016] Preferably, the membrane is at least one of Nafion 115 membrane, Nafion 117 membrane, porous zirconia membrane, and FAA-3-PK-130 membrane.

[0017] The beneficial effects of this invention are as follows: 1) This invention adds alkali metal ion additives to the electrolyte. On the one hand, alkali metal ions, especially cesium and potassium ions, are easily deformable and have the strongest interaction with the equally deformable nitrate ions. This regulates the electrostatic interaction between nitrate ions and the cathode in the electrolyte, promotes nitrate mass transfer, and improves the efficiency of electrochemical reduction of nitrate. On the other hand, by utilizing the large mismatch between the radii of cesium and potassium ions and water molecules, the hydrogen bond network in the interfacial water is most significantly disrupted. This changes the interaction at the electrode-solution interface, promotes the disruption of the hydrogen bond network in the interfacial water, suppresses the side reaction of hydrogen evolution, and improves the efficiency of electrochemical ammonia production. This enables the efficient synthesis of ammonia from nitrate wastewater and the parallel generation of electricity in a zinc-nitrate battery.

[0018] 2) The zinc-nitrate battery electrolyte of the present invention has a stable process, low cost, and simple operation, and has strong commercialization potential.

[0019] In summary, this invention alleviates the mass transfer barrier between nitrate ions and the cathode by using an electrolyte and improves the selectivity of nitrate ion reduction. Furthermore, it provides a feasible method for improving the selectivity of nitrate ion reduction and ammonia yield by achieving efficient ammonia synthesis and power generation in a zinc-nitrate battery. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a zinc-nitrate battery; In the diagram: 1. Cathode, 2. Anode, 3. Diaphragm, 4. Cathode cell, 5. Anode cell; Figure 2 The X-ray diffraction patterns of the foamed copper electrode in Example 2 before and after testing on an electrochemical workstation are shown below. Figure 3 The images are transmission electron microscope images of the foamed copper electrode of Example 2 before and after testing on an electrochemical workstation. ab represents before the reaction, and cd represents after the reaction. Figure 4 The image shows a scanning transmission electron microscope-energy dispersive spectroscopy (STEM) image of the foamed copper electrode of Example 2 tested on an electrochemical workstation. ad represents the image before the reaction, and eh represents the image after the reaction. Figure 5The polarization curves of the zinc-nitrate batteries in Example 2 and Comparative Example 6 are shown. Figure 6 The graph shows the discharge performance of the zinc-nitrate batteries of Example 2 and Comparative Example 6 at different current densities. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0022] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased commercially. Specifically, lithium nitrate, sodium nitrate, potassium nitrate, cesium nitrate, lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide were purchased from Maclean's. Nafion 117 and Nafion 115 membranes were purchased from Chemours. Porous zirconia membranes and FAA-3-PK-130 membranes were purchased from Shengerno Company; copper foam, copper sheets, zinc foam, and zinc sheets were purchased from Kunshan Shangte New Materials Co., Ltd.

[0023] In the embodiments of this invention, X-ray powder diffraction phase analysis of the samples was performed using an Empyrean-100 X-ray diffractometer from Panaco (Netherlands), with a Cu target, a Kα radiation source (λ=0.15418nm), a voltage of 40kV, and a current of 40mA. The fine internal structure analysis and energy-dispersive X-ray spectroscopy (EDS) observation of the samples were performed using a JEM-2100 transmission electron microscope from NEC Corporation. The evaluation of the electrochemical reduction of nitrate in a three-electrode system was conducted using a Gamry Instruments Interface 1010E electrochemical workstation.

[0024] The zinc-nitrate battery device in the following embodiments is implemented as follows Figure 1 Assemble the battery according to the structural diagram shown. The battery consists of a positive electrode 2, a negative electrode 1, and a separator 3. The cavity between the positive electrode 3 and the separator 3 is filled with positive electrolyte, and the cavity between the negative electrode 1 and the separator 3 is filled with negative electrolyte. A peristaltic pump is used to pump the electrolyte from the cathode cell 4 and the anode cell 5 into the cathode and anode, respectively. The material of the positive electrode 2 is at least one of foamed copper and copper sheet. The material of the negative electrode 1 is at least one of foamed zinc and zinc sheet. The separator 3 is at least one of Nafion 115 membrane, Nafion 117 membrane, porous zirconia separator, and FAA-3-PK-130 separator.

[0025] Example 1 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 and mix them in the cathode cell. Add 0.0756g of cesium hydroxide monohydrate and dilute with water to 90mL. Take 90mL of solution 1 in the anode cell. The electrolyte is named 1#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:0.25.

[0026] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested using a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 28.16 mW / cm². -2 .

[0027] Example 2 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.1512g of cesium hydroxide monohydrate, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 2#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:0.5.

[0028] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anolyte cells was pumped into the cathode and anolyte cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. Figure 6 As shown, the constant current discharge voltage of the battery is in the range of 10-50 mA cm⁻¹. -2 The range is higher than that of control sample 6, such as Figure 5 As shown, the highest power density of the battery is 30.16 mW cm⁻¹. -2 It is also higher than the control ratio of 6.

[0029] XRD tests were performed on the foamed copper electrode in Example 2 before and after testing on an electrochemical workstation. The results are as follows: Figure 2 As shown, it can be observed that before and after the test, the foamed copper is still elemental copper, and no change was observed.

[0030] SEM and EDS tests were performed on the foamed copper electrode in Example 2 before and after testing on an electrochemical workstation, and the results are as follows: Figure 3 and Figure 4 As shown, it can be seen that before and after the test, the appearance of the foamed copper remains unchanged and it is still a porous material, and the element distribution on the surface does not change.

[0031] Example 3 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.3024g of cesium hydroxide monohydrate, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 3#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:1.

[0032] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 25.30 mW / cm². -2 .

[0033] Example 4 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.025g of potassium hydroxide, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named #4, and the molar ratio of alkali, nitrate, and additive (potassium hydroxide) is 50:1:0.25.

[0034] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 27.59 mW / cm². -2 .

[0035] Example 5 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and dilute to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and dilute to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.0504g of potassium hydroxide, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 5#, and the molar ratio of alkali, nitrate, and additive (potassium hydroxide) is 50:1:0.5.

[0036] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 28.95 mW / cm². -2 .

[0037] Example 6 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.0504g of potassium hydroxide, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 6#, in which the molar ratio of alkali, nitrate, and additive (potassium hydroxide) is 50:1:1.

[0038] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 24.35 mW / cm². -2 .

[0039] Comparative Example 1 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, and dilute them with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 7#, in which the molar ratio of strong base to nitrate is 50:1.

[0040] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 21.89 mW / cm². -2 .

[0041] Comparative Example 2 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.6048g of cesium hydroxide monohydrate, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 8#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:2.

[0042] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery reached 20.27 mW / cm². -2 .

[0043] Comparative Example 3 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 0.9072g of cesium hydroxide monohydrate, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 9#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:3.

[0044] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 15.12 mW / cm². -2 .

[0045] Comparative Example 4 Weigh 360g of sodium hydroxide into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 1. Weigh 17g of sodium nitrate into a beaker, dissolve it in water, transfer it to a volumetric flask, and bring the volume to 2L to obtain solution 2. Take 20mL of solution 1 and 18mL of solution 2 into the cathode cell, add 1.512g of cesium hydroxide monohydrate, and dilute with water to 90mL. Take 90mL of solution 1 into the anode cell. The electrolyte is named 10#, and the molar ratio of alkali, nitrate, and additive (cesium hydroxide) is 50:1:5.

[0046] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 10.65 mW / cm². -2 .

[0047] Comparative Example 5 Compared to Example 1, sodium hydroxide was used as an additive. The specific method was as follows: 360g of sodium hydroxide was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 1; 17g of sodium nitrate was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 2; 20.1mL of solution 1 and 18mL of solution 2 were mixed in the cathode cell and diluted with water to 90mL; 90mL of solution 1 was then added to the anode cell. The electrolyte was named 11#, and the molar ratio of alkali, nitrate, and additive (sodium hydroxide) was 50:1:0.25.

[0048] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 20.35 mW / cm². -2 .

[0049] Comparative Example 6 Compared to Example 2, sodium hydroxide was used as an additive. The specific method was as follows: 360g of sodium hydroxide was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 1; 17g of sodium nitrate was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 2; 20.2mL of solution 1 and 18mL of solution 2 were placed in the cathode cell and diluted with water to 90mL; 90mL of solution 1 was placed in the anode cell. The electrolyte was named 12#, and the molar ratio of strong alkali, nitrate, and additive (sodium hydroxide) was 50:1:0.5.

[0050] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 18.72 mW / cm². -2 .

[0051] Comparative Example 7 Compared to Example 3, sodium hydroxide was used as an additive. The specific method was as follows: 360g of sodium hydroxide was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 1; 17g of sodium nitrate was weighed into a beaker, dissolved in water, and transferred to a volumetric flask, then diluted to 2L to obtain solution 2; 20.4mL of solution 1 and 18mL of solution 2 were placed in the cathode cell and diluted with water to 90mL; 90mL of solution 1 was placed in the anode cell. The electrolyte was named 13#, and the ratio of strong alkali, nitrate, and additive (sodium hydroxide) was 50:1:1.

[0052] The battery device was assembled using Nafion 115 as the diaphragm, copper foam electrode as the cathode, and zinc foam electrode as the anode, and pumped at 100 mL / min using a peristaltic pump. -1 The electrolyte in the cathode and anode cells was pumped into the cathode and anode cells at different rates. Polarization curves were scanned and the galvanostatic discharge capability was tested on a Gamry Instruments Interface 1010E electrochemical workstation. The highest power density of the battery was 15.45 mW / cm². -2 .

[0053] The above description is merely a few preferred embodiments of the present invention and is not intended to limit the present invention in any way. It should be noted that any modifications or alterations made by those skilled in the art without departing from the scope of the present invention using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A zinc-nitrate battery electrolyte, characterized in that, The electrolyte comprises an electrolyte nitrate, an alkali, and an alkali metal ion additive; the alkali metal ion additive is cesium hydroxide or potassium hydroxide.

2. The zinc-nitrate battery electrolyte according to claim 1, characterized in that, The electrolyte nitrate is at least one of lithium nitrate, sodium nitrate, potassium nitrate, and cesium nitrate.

3. The zinc-nitrate battery electrolyte according to claim 1, characterized in that, The alkali is sodium hydroxide.

4. The zinc-nitrate battery electrolyte according to claim 1, characterized in that, The concentration of the alkali metal ion additive in the electrolyte is 0.005~0.02 mol / L. -1 .

5. The zinc-nitrate battery electrolyte according to claim 1, characterized in that, The molar ratio of the alkali, electrolyte nitrate and alkali metal ion additive is 50:1:(0.25~1).

6. A method for preparing the zinc-nitrate battery electrolyte according to any one of claims 1-5, characterized in that, An alkali metal ion additive is added to an alkaline solution containing electrolyte nitrate, and the solution is stirred until homogeneous at room temperature to obtain an electrolyte.

7. A zinc-nitrate battery, the battery comprising a positive electrode, a negative electrode, and a separator, wherein the cavity between the positive electrode and the separator is filled with a positive electrolyte, and the cavity between the negative electrode and the separator is filled with a negative electrolyte, characterized in that, The negative electrode electrolyte is the electrolyte according to any one of claims 1-5.

8. The zinc-nitrate battery according to claim 7, characterized in that, The positive electrode material is at least one of copper foam or copper sheet.

9. The zinc-nitrate battery according to claim 7, characterized in that, The negative electrode material is at least one of zinc foam or zinc sheet.

10. The zinc-nitrate battery according to claim 7, characterized in that, The membrane is at least one of Nafion 115 membrane, Nafion 117 membrane, porous zirconia membrane, and FAA-3-PK-130 membrane.

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