A water-based liquid electrode battery based on self-adsorption and self-layering effect

Abstract

The application discloses a water-based liquid electrode battery based on self-adsorption and self-layering effect, which is prepared by dissolving hydrophobic imidazole-containing water-soluble salt and double-trifluoromethyl sulfonimide ion-containing water-soluble salt in deionized water solution respectively, mixing and standing the two water solutions, mixing adsorptive carbon material, conductive carbon black and polyvinylidene fluoride, dispersing in an organic solvent, stirring into a thick mixture with a sugar-like consistency, smearing on a current collector, drying in a vacuum drying box, using commercial zinc foil as an anode of the battery, using Whatman filter membrane soaked by 3 mol / L zinc triflate as a positive and negative electrode diaphragm, and using the prepared ion liquid soaked current collector as a cathode to construct the water-based liquid electrode battery based on self-adsorption and self-layering effect. The self-assembly 1-ethyl-3-methyl imidazole double (trifluoromethyl sulfonic) acyl imidazole liquid electrode realizes liquid self-separation, fixation of redox active material and ion conduction at the same time.

Description

Technical Field

[0001] This application belongs to the field of liquid batteries, and in particular relates to an aqueous liquid electrode battery based on self-adsorption and self-stratification effects. Background Technology

[0002] With the gradual depletion of fossil fuels and the increasing environmental problems caused by their extensive use, scientists and engineers from governments worldwide are intensifying their efforts to convert clean and sustainable new energy sources, such as solar, nuclear, and wind power, into electricity and integrate them into the power grid. This aims to ensure the convenience of modern life while gradually reducing and eliminating dependence on fossil fuels. To better store clean and convenient electricity in various aspects of life and ensure the normal operation of various devices, the development of high-performance energy storage battery technology has become an indispensable and crucial step.

[0003] Current battery technology research primarily focuses on developing high-capacity, long-life, fast-charging, low-cost, pollution-free battery materials, and safe rechargeable batteries. These simultaneous requirements make the development of high-performance batteries analogous to the "barrel principle"—it needs to meet as many practical needs as possible at once.

[0004] The energy storage principle of electrochemical batteries mainly relies on creating a chemical potential difference by selecting appropriate electrode materials. These electrode materials influence the overall output voltage of the battery by storing (or releasing) charged ions. From the earliest discovery of intercalated electrode materials to the design and construction of various composite electrode materials, almost all are based on solid-state materials. However, the charging and discharging principle of electrode materials depends precisely on the absorption (or release) of charged ions by the electrode material. This process inevitably impacts the original microscopic atomic distribution structure of the electrode material. With repeated absorption and release, over time, the microscopic structure of the electrode material collapses, macroscopically causing the battery's charging and discharging capacity to disappear. To maintain its original microscopic atomic structure for as long as possible, thereby achieving an ultra-long battery life, it is crucial that the electrode material's microscopic structure is not impacted, or only minimally impacted, during charging and discharging. It is easy to see that there is a serious contradiction between traditional battery charging and discharging methods and the desired long-life battery. This suggests that further research and development of electrode materials needs to be rethought, and finding a charge-discharge mechanism that does not change the microstructure of the electrode material during the charge-discharge process will theoretically fundamentally meet the needs of long-life batteries.

[0005] Based on the above analysis, liquid electrodes, due to their lack of a fixed microscopic atomic structure, perfectly meet the requirements for zero-lattice-stress electrode materials. Currently, the three main types of liquid electrodes under development are liquid metal electrodes, molten salt electrodes, and liquid organic electrodes. The concept of liquid metal electrodes was first proposed in 2014 by MIT professor Donald R. Sadoway, who also reported on batteries based on high-temperature liquid metal electrodes. In the following years, batteries based on liquid metal electrodes experienced slow development. Similar to molten salt electrodes, liquid metal electrode batteries generally require high operating temperatures to maintain the metal electrode in a liquid state (except for liquid metal electrodes such as sodium-potassium alloys (Na / K) and gallium-indium alloys (Ga / In). Both liquid metal batteries and molten salt electrode batteries generally require ceramic solid electrolytes to achieve isolation between the anode and cathode and to facilitate carrier transport. In summary, batteries based on these two types of liquid electrodes are limited by harsh operating conditions, high large-scale fabrication costs, and serious safety hazards. In contrast, flow batteries are typical liquid electrode batteries that operate at room temperature. Research and development of flow batteries has been underway for over twenty years, but their normal charging and discharging relies on a costly ion-conducting membrane between the positive and negative electrolytes to prevent miscibility and cross-contamination of the active electrolytes. However, the effectiveness of this expensive ion-conducting membrane is limited. Furthermore, although the redox-active molecules (ions) in the liquid electrode have no fixed structural constraints and can ionize freely, their air sensitivity in their oxidation (reduction) states limits the battery's operation to a continuously inert protective gas environment. These stringent operating conditions, the high cost of components such as the membrane, and the large amount of organic matter produced, which contradicts environmental and sustainable development principles, have ultimately limited their large-scale practical application. Summary of the Invention

[0006] Technical problem solved: This application provides an aqueous liquid electrode battery based on self-adsorption and self-stratification effects, which solves the technical problems in the prior art such as the collapse and disintegration of the microstructure of the electrode material, which macroscopically causes the battery to lose its charging and discharging capabilities.

[0007] Technical solution:

[0008] An aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0009] The first step is to prepare a self-assembled ionic liquid electrode: Take a water-soluble salt containing a hydrophobic imidazole derivative and a water-soluble salt containing bis(trifluoromethanesulfonyl)imide ions in a 1:1 molar ratio, and dissolve each in deionized water to prepare a 10 mol / L aqueous solution, stirring until completely dissolved. Then, pour both aqueous solutions directly into the same container, mix, and let stand for 8-24 hours to allow for ionic self-assembly. This will result in a layered state, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The relative positions of the two liquid substances depend on their densities. The ionic liquid layer is then set aside.

[0010] The second step is the assembly of the current collector: the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 4-7:2-5:1, then dispersed in an organic solvent and stirred into a syrupy viscous mixture; the prepared viscous mixture is coated onto the current collector to a thickness of 50-100 micrometers; the coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours;

[0011] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 3 moles per liter of zinc trifluoromethanesulfonate electrolyte is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0012] Furthermore, the water-soluble salt containing hydrophobic imidazoles is 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium bromide, or 1-ethyl-3-methylimidazolium chloride.

[0013] Furthermore, the water-soluble salt containing bis(trifluoromethanesulfonyl)imide is lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, or zinc bis(trifluoromethanesulfonyl)imide.

[0014] Furthermore, the organic solvent is methylpyrrolidone. The total weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride powder is calculated, and each gram of total powder weight is dispersed in 4 ml of organic solvent.

[0015] Furthermore, the adsorbent carbon material is activated carbon powder, single-walled carbon nanotubes, multi-walled carbon nanotubes, or reduced graphene, wherein unlimited amounts of zinc iodide or zinc bromide are added or not added.

[0016] Furthermore, the current collector is a carbon material, including but not limited to carbon cloth, conductive carbon paper, and carbon felt.

[0017] Furthermore, the aqueous liquid electrode battery based on self-adsorption and self-stratification effects is a zinc-iodine aqueous liquid electrode battery or a zinc-bromine aqueous liquid electrode battery.

[0018] Furthermore, in the zinc-iodine aqueous liquid electrode battery, the current collector wetted by the 1-ethyl-3-methylimidazolium iodide-bis(trifluoromethanesulfonyl)imide ionic liquid serves as the cathode, and the cation source in the ionic liquid cathode is 1-ethyl-3-methylimidazolium iodide.

[0019] Furthermore, the electrolyte in the zinc-bromine aqueous liquid electrode battery is 3 mol / L zinc trifluoromethanesulfonate and 20 mol / L lithium bis(trifluoromethanesulfonyl)imide; the cathode is a current collector wetted by 1-ethyl-3-methylimidazolium bromide-bis(trifluoromethanesulfonyl)imide ionic liquid, and the cation source in the ionic liquid cathode is 1-ethyl-3-methylimidazolium bromide.

[0020] Furthermore, in the third step, 20 moles of lithium bis(trifluoromethanesulfonyl)imide may or may not be added to the zinc trifluoromethanesulfonate electrolyte at a concentration of 3 moles per liter.

[0021] Explanation of the principle of this application: The membrane-free, self-assembled, layered aqueous electrolyte / liquid electrode design represents a further effective innovation based on existing liquid battery design concepts. This ionic liquid electrode possesses a naturally coherent three-dimensional ionic conductivity network and exhibits strong adsorption for halogen redox reactions. This battery design reduces production and operation / maintenance costs while ensuring long-term battery operation, improves safety, avoids organic pollution, and simultaneously meets as many parameters as possible required by the "barrel principle" in practical battery use.

[0022] Beneficial effects:

[0023] 1. This self-assembled 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide liquid electrode simultaneously achieves liquid phase separation, fixation of redox active materials, and unimpeded ion conduction;

[0024] 2. This liquid electrode not only has no lattice strain, but also enables ion self-assembly in aqueous solution;

[0025] 3. During the self-assembly process, the hydrophobic ionic liquid undergoes mutual charge transfer driven by thermodynamics and electrostatics, thereby forming the final ionic liquid electrode;

[0026] 4. This ionic liquid exhibits strong adsorption of halogens through its inherent three-dimensional hydrogen bond network, while ensuring carrier migration during charging and discharging.

[0027] 5. This zinc-iodine (bromine) battery is designed to be thoroughly fire-resistant, ensuring safe use of the battery. Attached Figure Description

[0028] Figure 1 Figure 1 shows the self-assembled 1-ethyl-3-methylimidazolium and bis(trifluoromethanesulfonyl)imide ionic liquids of this application; Figure A shows the ionic liquid using 1-ethyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide as source reagents, Figure B shows the ionic liquid using 1-ethyl-3-methylimidazolium bromide and lithium bis(trifluoromethanesulfonyl)imide as source reagents, and Figure C shows the ionic liquid using 1-ethyl-3-methylimidazolium iodide and lithium bis(trifluoromethanesulfonyl)imide as source reagents.

[0029] Figure 2 Figure A shows the ionic liquid diagram of the self-assembled 1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide according to this application. Figure A shows the ionic liquid diagram using different concentrations (1-10m) of 1-ethyl-3-methylimidazolium chloride and lithium(trifluoromethanesulfonyl)imide as source reagents. Figure B shows the ionic liquid diagram with 1-ethyl-3-methylimidazolium iodide and lithium(trifluoromethanesulfonyl)imide as source reagents on the left, 1-ethyl-3-methylimidazolium iodide and lithium(trifluoromethanesulfonyl)imide as source reagents on the middle, 1-ethyl-3-methylimidazolium iodide and sodium(trifluoromethanesulfonyl)imide as source reagents on the right, and 1-ethyl-3-methylimidazolium iodide and zinc(trifluoromethanesulfonyl)imide as source reagents on the right.

[0030] Figure 3 This is a schematic diagram illustrating the overall concept of the self-assembled battery in this application;

[0031] Figure 4 This is a photograph of the assembled aqueous zinc-iodine beaker battery and its charging and discharging phenomena.

[0032] Figure 5 Figures show the electrochemical performance of the aqueous zinc-iodine battery assembled in this application; Figure A is the cyclic voltammogram of the aqueous zinc-iodine battery; Figure B is the rate performance of the aqueous zinc-iodine battery; Figure C is the charge-discharge voltage trajectory corresponding to the rate performance of the aqueous zinc-iodine battery; Figures D and F are the long-cycle life test results of the aqueous zinc-iodine battery at current densities of 0.5 mA / cm² and 5 mA / cm², respectively; Figures E and G are the charge-discharge voltage trajectory corresponding to the long-cycle test of the aqueous zinc-iodine battery at current densities of 0.5 mA / cm² and 5 mA / cm², respectively.

[0033] Figure 6 This is a photograph of the assembled aqueous zinc-bromine beaker battery and its charge / discharge phenomena.

[0034] Figure 7Figure 1 shows the electrochemical performance of the aqueous zinc-iodine battery assembled in this application; Figure 2 shows the structural schematic of the aqueous zinc-bromine battery, Figure 3 shows the cyclic voltammetry curve of the aqueous zinc-bromine battery, Figure 4 shows the rate performance of the aqueous zinc-bromine battery, Figure 5 shows the charge-discharge voltage change trajectory corresponding to the rate performance of the aqueous zinc-bromine battery, Figure 6 shows the long cycle life test results of the aqueous zinc-bromine battery, and Figure 7 shows the charge-discharge voltage change trajectory corresponding to the long cycle test of the aqueous zinc-bromine battery. Detailed Implementation

[0035] The following embodiments are intended to enable those skilled in the art to more fully understand this application, but do not limit this application in any way.

[0036] Example 1

[0037] A zinc-iodine aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0038] The first step is to prepare a self-assembled ionic liquid electrode: Take 1-ethyl-3-methylimidazolium iodide and lithium bis(trifluoromethanesulfonyl)imide in a molar ratio of 1:1, and dissolve them separately in deionized water to prepare aqueous solutions of 10-20 mol / L, stirring until completely dissolved; then pour the two aqueous solutions directly into the same container, mix, and let stand for 8-24 hours to carry out the ionic self-assembly process; finally, a layered state is formed, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The upper and lower positions of the two liquid substances depend on their densities; the ionic liquid layer is then set aside.

[0039] The second step is the assembly of the current collector: Activated carbon powder, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 7:2:1. The total powder weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride is calculated. Each gram of total powder weight is dispersed in 4 ml of methylpyrrolidone organic solvent and stirred into a syrupy viscous mixture. The prepared viscous mixture is coated onto the carbon cloth current collector to a thickness of 50-100 micrometers. The coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours.

[0040] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 3 moles per liter of zinc trifluoromethanesulfonate electrolyte is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0041] Example 2

[0042] A zinc-bromine aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0043] The first step is to prepare a self-assembled ionic liquid electrode: 1-ethyl-3-methylimidazolium bromide and lithium bis(trifluoromethanesulfonyl)imide are mixed in a 1:1 molar ratio and dissolved separately in water to prepare 10-20 mol / L aqueous solutions. The solutions are stirred until completely dissolved. Then, the two aqueous solutions are poured directly into the same container, mixed, and allowed to stand for 8-24 hours to allow for ionic self-assembly. This results in a layered state, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The relative positions of the two liquid substances depend on their densities. The ionic liquid layer is then set aside.

[0044] The second step is the assembly of the current collector: Weigh and mix the adsorbent activated carbon powder, conductive carbon black, and polyvinylidene fluoride in a weight ratio of 7:2:1. Calculate the total powder weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride. Disperse each gram of total powder weight with 4 ml of methylpyrrolidone organic solvent and stir to form a syrupy viscous mixture. Coat the prepared viscous mixture onto the carbon cloth current collector to a thickness of 50-100 micrometers. Place the coated carbon cloth current collector in a vacuum drying oven and vacuum dry at 100-150 degrees Celsius for 8-24 hours.

[0045] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 20 moles of lithium bis(trifluoromethanesulfonyl)imide and 3 moles per liter of zinc trifluoromethanesulfonate is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0046] Example 3

[0047] A zinc-bromine aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0048] The first step is to prepare a self-assembled ionic liquid electrode: 1-ethyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide are mixed in a molar ratio of 1:1 and dissolved separately in deionized water to prepare aqueous solutions of 10-20 mol / L. The solutions are then stirred until completely dissolved. The two aqueous solutions are then poured directly into the same container and allowed to stand for 8-24 hours to allow for ionic self-assembly. This process results in a layered state, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The relative positions of the two liquid substances depend on their densities. The ionic liquid layer is then set aside for later use.

[0049] The second step is the assembly of the current collector: Zinc bromide, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 7:2:1. The total powder weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride is calculated. Each gram of total powder weight is dispersed in 4 ml of methylpyrrolidone organic solvent and stirred into a syrupy viscous mixture. The prepared viscous mixture is coated onto the carbon cloth current collector to a thickness of 50-100 micrometers. The coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours.

[0050] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 20 moles of lithium bis(trifluoromethanesulfonyl)imide and 3 moles per liter of zinc trifluoromethanesulfonate electrolyte is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0051] Example 4

[0052] A zinc-iodine aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0053] The first step is to prepare a self-assembled ionic liquid electrode: Take 1-ethyl-3-methylimidazolium iodide and sodium bis(trifluoromethanesulfonyl)imide in a molar ratio of 1:1, and dissolve them separately in deionized water to prepare an aqueous solution of 10-20 mol / L. Stir until completely dissolved. Then, pour the two aqueous solutions directly into the same container without any difference, mix them, and let them stand for 8-24 hours to carry out the ionic self-assembly process. Finally, a layered state is formed, with the upper and lower layers being composed of ionic liquid and aqueous solution, respectively. The upper and lower positions of the two liquid substances depend on their densities. Take the ionic liquid layer for later use.

[0054] The second step is the assembly of the current collector: Activated carbon powder, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 7:2:1. The total powder weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride is calculated. Each gram of total powder weight is dispersed in 4 ml of methylpyrrolidone organic solvent and stirred into a syrupy viscous mixture. The prepared viscous mixture is coated onto the carbon cloth current collector to a thickness of 50-100 micrometers. The coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours.

[0055] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 3 moles per liter of zinc trifluoromethanesulfonate electrolyte is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0056] Example 5

[0057] A zinc-iodine aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes the following specific steps:

[0058] The first step is to prepare a self-assembled ionic liquid electrode: Take 1-ethyl-3-methylimidazolium iodide and zinc bis(trifluoromethanesulfonyl)imide in a molar ratio of 1:1, and dissolve them separately in deionized water to prepare an aqueous solution of 10-20 mol / L. Stir until completely dissolved. Then, pour the two aqueous solutions directly into the same container, mix, and let stand for 8-24 hours to carry out the ionic self-assembly process. This will eventually form a layered state, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The relative positions of the two liquid substances depend on their densities. The ionic liquid layer is then set aside.

[0059] The second step is the assembly of the current collector: Activated carbon powder, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 7:2:1. The total powder weight of the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride is calculated. Each gram of total powder weight is dispersed in 4 ml of methylpyrrolidone organic solvent and stirred into a syrupy viscous mixture. The prepared viscous mixture is coated onto the carbon cloth current collector to a thickness of 50-100 micrometers. The coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours.

[0060] The third step is the fabrication of the battery device: commercial zinc foil is used as the anode of the battery, and a Whatman filter membrane wetted with 3 moles per liter of zinc trifluoromethanesulfonate electrolyte is used as the positive and negative electrode separator. The cathode is prepared by wetting the current collector dried in the second step with the ionic liquid obtained in the first step, with a wetting amount of 20 microliters per square centimeter. Then, an aqueous liquid electrode battery based on self-adsorption and self-stratification effects is constructed.

[0061] This application Figure 1-7 The conclusions that can be drawn from each are as follows:

[0062] like Figure 1 As shown, Figure 1Figure 1 shows the self-assembled 1-ethyl-3-methylimidazolium and bis(trifluoromethanesulfonyl)imide ionic liquids of this application; Figure A shows the ionic liquid using 1-ethyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide as source reagents, Figure B shows the ionic liquid using 1-ethyl-3-methylimidazolium bromide and lithium bis(trifluoromethanesulfonyl)imide as source reagents, and Figure C shows the ionic liquid using 1-ethyl-3-methylimidazolium iodide and lithium bis(trifluoromethanesulfonyl)imide as source reagents. Figure 1 This demonstrates the broad compatibility of cation source reagents in ionic liquids;

[0063] like Figure 2 As shown, Figure 2 Figure A shows the ionic liquid diagram of the self-assembled 1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide of this application. Figure A shows the ionic liquid diagram using 1-ethyl-3-methylimidazolium chloride and lithium(trifluoromethanesulfonyl)imide at different concentrations (1-10m) as source reagents. In Figure B, the left diagram shows the ionic liquid diagram using 1-ethyl-3-methylimidazolium iodide and lithium(trifluoromethanesulfonyl)imide as source reagents; the middle diagram shows the ionic liquid diagram using 1-ethyl-3-methylimidazolium iodide and sodium(trifluoromethanesulfonyl)imide as source reagents; and the right diagram shows the ionic liquid diagram using 1-ethyl-3-methylimidazolium iodide and zinc(trifluoromethanesulfonyl)imide as source reagents. 1m equals 1 mole of chemical reagent dissolved in 1 kg of deionized water. Figure 2 This demonstrates the compatibility of the self-assembly process for ionic liquids with different preparation concentrations, as well as the broad compatibility of anion source reagents in ionic liquids.

[0064] Figure 3 This is a schematic diagram illustrating the overall concept of the self-assembled battery in this application; Figure 3 Explain the scientific principles behind this self-assembled liquid electrode battery design.

[0065] Figure 4 This is a photograph of the assembled aqueous zinc-iodine beaker battery and its charging and discharging phenomena. Figure 4 This demonstrates that the liquid electrode has an effective binding effect on iodine-active substances;

[0066] Figure 5 Figures show the electrochemical performance of the aqueous zinc-iodine battery assembled in this application; Figure A is the cyclic voltammogram of the aqueous zinc-iodine battery; Figure B is the rate performance of the aqueous zinc-iodine battery; Figure C is the charge-discharge voltage trajectory corresponding to the rate performance of the aqueous zinc-iodine battery; Figures D and F are the long-cycle life test results of the aqueous zinc-iodine battery at current densities of 0.5 mA / cm² and 5 mA / cm², respectively; Figures E and G are the charge-discharge voltage trajectory corresponding to the long-cycle test of the aqueous zinc-iodine battery at current densities of 0.5 mA / cm² and 5 mA / cm², respectively. Figure 5 This demonstrates that the zinc-iodine battery constructed using this design exhibits superior electrochemical performance;

[0067] Figure 6 This is a photograph of the assembled aqueous zinc-bromine beaker battery and its charge / discharge phenomena. Figure 6 This demonstrates that the liquid electrode has an effective binding effect on bromine-active substances;

[0068] Figure 7 Figure 1 shows the electrochemical performance of the aqueous zinc-iodine battery assembled in this application; Figure 2 shows the structural schematic of the aqueous zinc-bromine battery, Figure 3 shows the cyclic voltammetry curve of the aqueous zinc-bromine battery, Figure 4 shows the rate performance of the aqueous zinc-bromine battery, Figure 5 shows the charge-discharge voltage change trajectory corresponding to the rate performance of the aqueous zinc-bromine battery, Figure 6 shows the long cycle life test results of the aqueous zinc-bromine battery, and Figure 7 shows the charge-discharge voltage change trajectory corresponding to the long cycle test of the aqueous zinc-bromine battery. Figure 7 This demonstrates that the zinc-bromine battery constructed using this design exhibits superior electrochemical performance.

Claims

1. An aqueous liquid electrode battery based on self-adsorption and self-stratification effects, characterized in that, The aqueous liquid electrode battery based on self-adsorption and self-stratification effects includes: Commercially available zinc foil is used as the anode in batteries; Whatman filter membranes, wetted with 3 mol / L zinc trifluoromethanesulfonate electrolyte, are used as positive and negative electrode separators; A self-assembled ionic liquid electrode is used as the cathode of the battery by wetting the current collector. The method for preparing the cathode is as follows: The first step is to prepare a self-assembled ionic liquid electrode: Take a water-soluble salt containing hydrophobic imidazole and a water-soluble salt containing bis(trifluoromethanesulfonyl)imide ions in a molar ratio of 1:1, and dissolve them separately in deionized water to prepare aqueous solutions of 10-20 mol / L, stirring until completely dissolved; then pour the two aqueous solutions directly into the same container, mix them, and let them stand for 8-24 hours to carry out the ionic self-assembly process; finally, a layered state is formed, with the upper and lower layers consisting of an ionic liquid and an aqueous solution, respectively. The upper and lower positions of the two liquid substances depend on their densities; the ionic liquid layer is then taken for later use. The second step is the assembly of the current collector: the adsorbent carbon material, conductive carbon black, and polyvinylidene fluoride are weighed and mixed in a weight ratio of 4-7:2-5:1, then dispersed in an organic solvent and stirred into a syrupy viscous mixture; the prepared viscous mixture is coated onto the current collector to a thickness of 50-100 micrometers; the coated current collector is placed in a vacuum drying oven and vacuum dried at 100-150 degrees Celsius for 8-24 hours; The third step is the preparation of the cathode: the self-assembled ionic liquid electrode prepared in the first step is used to wet the current collector dried in the second step, with a wettability of 20 microliters per square centimeter. The water-soluble salt containing hydrophobic imidazoles is 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium bromide, or 1-ethyl-3-methylimidazolium chloride.

2. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The water-soluble salt containing bis(trifluoromethanesulfonyl)imide is lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, or zinc bis(trifluoromethanesulfonyl)imide.

3. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The organic solvent is methylpyrrolidone. The total weight of the adsorbent carbon material, conductive carbon black and polyvinylidene fluoride powder is calculated, and each gram of total powder weight is dispersed in 4 ml of organic solvent.

4. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The adsorbent carbon material is activated carbon powder, single-walled carbon nanotubes, multi-walled carbon nanotubes, or reduced graphene, with or without an unlimited amount of zinc iodide or zinc bromide added.

5. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The current collector is a carbon material, including but not limited to carbon cloth, conductive carbon paper, and carbon felt.

6. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The aqueous liquid electrode battery based on self-adsorption and self-stratification effects is a zinc-iodine aqueous liquid electrode battery or a zinc-bromine aqueous liquid electrode battery.

7. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 6, characterized in that: In the zinc-iodine aqueous liquid electrode battery, the current collector wetted by the 1-ethyl-3-methylimidazolium iodide-bis(trifluoromethanesulfonyl)imide ionic liquid serves as the cathode, and the cation source in the cathode is 1-ethyl-3-methylimidazolium iodide.

8. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 6, characterized in that: The electrolyte in the zinc-bromine aqueous liquid electrode battery is 3 mol / L zinc trifluoromethanesulfonate and 20 mol / L lithium bis(trifluoromethanesulfonyl)imide; the cathode is a current collector wetted with 1-ethyl-3-methylimidazolium bromide-bis(trifluoromethanesulfonyl)imide ionic liquid, and the cation source in the ionic liquid cathode is 1-ethyl-3-methylimidazolium bromide.

9. The aqueous liquid electrode battery based on self-adsorption and self-stratification effects according to claim 1, characterized in that: The zinc trifluoromethanesulfonate electrolyte is prepared with or without the addition of lithium bis(trifluoromethanesulfonyl)imide at a concentration of 3 mol / L.

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