Zinc-based rechargeable redox static energy storage device

Abstract

A zinc-based rechargeable redox flow static energy storage device (1) comprising a cathode (2) and an anode (3) both impregnated with a eutectic electrolyte, the cathode (2) comprising a carbon material-binder composition, the anode (3) comprising a carbon material-zinc material-binder composition, the eutectic electrolyte comprising one or more inorganic transition metal salts of zinc, one or more metal hydroxides and a eutectic solvent comprising a methanesulfonic acid derivative, an ammonium salt and a hydrogen bond donor; a separator (4) separating the cathode (2) and the anode (3) allowing ion exchange between the cathode and the anode through ion permeability; and current collectors (5, 6) connected to the cathode (2) and the anode (3), respectively.

Description

Technical Field

[0001] This invention relates to a rechargeable redox energy storage device, and more specifically to a zinc-based rechargeable redox static energy storage device, which has high energy efficiency, long cycle life, 100% DOD and high-rate charge and discharge capability. Background Technology

[0002] With the continued depletion of fossil fuels and the increasing environmental problems associated with their use, technology is shifting towards green and sustainable alternatives for energy production, utilization, and storage. Using green and renewable energy sources such as solar, wind, geothermal, and tidal power for electricity generation is now emerging as a promising solution to meet the growing energy demands of more equipment, technologies, and transportation. However, effectively utilizing these renewable energy sources to meet energy needs faces many key challenges due to the intermittency of these resources and the lack of suitable facilities to store their energy in appropriate forms. Converting energy from renewable resources into electricity and storing it for later use is the most convenient and efficient approach.

[0003] For a long time, various energy storage devices, such as batteries, have been used for electricity storage purposes and have been continuously improved. Among existing rechargeable energy storage devices, lithium-ion energy storage devices dominate the market due to their high energy density, and their applications include electronic products (mobile phones, laptops, and smartwatches, etc.) and automotive components. However, lithium-ion batteries have their drawbacks, including supply chain issues, high costs of materials and assembly lines, environmental hazards during disposal, and, most importantly, the safety of the final product. The review reports by Xue Wang et al., entitled “Economic and environmental characterization of an evolving Li-ionbattery waste stream” (http: / / dx.doi.org / 10.1016 / j.jenvman.2014.01.021) and Yanrong Wang et al., entitled “Emerging non-lithium ion batteries” (http: / / dx.doi.org / 10.1016 / j.ensm.2016.04.001), discuss the various inherent drawbacks and environmental hazards of lithium-ion energy storage devices.

[0004] Other energy storage devices, such as lead-acid batteries, have poor performance, with a cycle life of 300-500 cycles and a coulombic efficiency of 70%, which can reach up to 90% under special design conditions. Although review reports such as Xiaopeng Chen et al.'s "An Overview of Lithium-ion Batteries for Electric Vehicles" published in IEEE, DOI:10.1109 / ASSCC.2012.6523269; Carl Johan Rydh et al.'s "Energy analysis of batteries in photovoltaic systems. Part I: Performance and energy requirements" published in Energy Conservation & Management, doi:10.1016 / j.enconman.2004.10.003; and Xiayue Fan's "Battery Technologies for Grid-Level Large-Scale Electrical Energy Storage, https: / / doi.org / 10.1007 / s12209-019-00231-w" disclose various other energy storage device chemistry such as lead-acid batteries, various shortcomings still exist that need to be addressed.

[0005] The use of lead and sulfuric acid is also an environmental issue (see the review article "Study on the environmental risk assessment of lead-acid batteries" by Jing Zhang et al., published in Procedia Environmental Sciences, doi: 10.1016 / j.proenv.2016.02.103). Nickel-metal hydride batteries suffer from low energy density, high self-discharge rate, recycling problems, and poor performance at high temperatures. The main problems associated with nickel-cadmium batteries are cadmium toxicity, as well as low energy density and rapid discharge rate (see PJ.TSAI et al., "Nickel-based batteries: materials and chemistry", DOI: 10.1533 / 9780857097378.3.309).

[0006] Recently, other rechargeable energy storage devices have been chemically based on Zn. 2+ Ca 2+ Mg 2+ and Na +Zinc chemistry offers safe and promising outputs, attracting researchers' attention. Among these energy storage device alternatives, zinc chemistry is particularly noteworthy due to its abundance, low cost, high chemical and physical stability at both room and high temperatures, recyclability, eco-friendliness, and high use-related safety. Furthermore, zinc offers high anodic capacity, non-toxic properties, and a low redox potential (-0.76V) relative to the standard hydrogen electrode. Zinc has been used in numerous energy storage device chemistry applications to date, such as zinc-air batteries, zinc-ion batteries, zinc-manganese dioxide batteries, zinc-bromine batteries, and nickel-zinc batteries. Among these zinc-based batteries, the earliest zinc-manganese dioxide batteries have gained popularity due to their low cost and high energy density. A review by Guozhao Fang et al., entitled "Recent Advances in Aqueous Zinc-Ion Batteries," attempts to mention various recent developments in zinc-ion battery technology, but many shortcomings remain to be addressed.

[0007] The performance of rechargeable zinc energy storage devices depends on the chemical properties of the salt, the concentration used, the electrolyte, and the materials used as electrodes. Ionic liquids, typically composed of bulky asymmetric organic cations and organic / inorganic anions, are another solvent being explored as a potential solution to overcome the limitations of existing electrolytes used in zinc-based rechargeable energy storage devices. Even eutectic solvent-based electrolytes, widely referred to as deep eutectic solvent (DES)-based electrolytes, are being tested as potential alternatives to existing electrolytes. However, the limitations of ionic liquids, and even eutectic solvent-based electrolytes, restrict their use as electrolytes in zinc-based rechargeable energy storage devices. The morphology of zinc deposits depends on the constituent ions of the ionic liquid. Issues such as cost, viscosity, and toxicity limit the use of existing electrolytes as suitable electrolytes. The technology for using ionic liquids or eutectic solvent-based electrolytes as electrolytes in zinc-based rechargeable energy storage devices is in its very early stages, and much remains to be explored.

[0008] Electrodes have a significant impact on the efficiency and lifespan of energy storage devices. Furthermore, the surface area of ​​the electrodes used in the reaction plays a crucial role in the performance of the energy storage device. Therefore, there is always a desire for more suitable electrode materials with high surface area and physical, chemical, and structural stability to improve the overall performance and lifespan of energy storage devices.

[0009] Many efforts have been made in the past to obtain high-efficiency rechargeable zinc-manganese dioxide batteries. However, rechargeable zinc energy storage devices suffer from problems related to zinc dendrite formation, and the irreversibility of the reaction leads to poor performance, low capacity, and limited cycle life. Therefore, although zinc energy storage devices offer recyclability, cost-effectiveness, ease of manufacture (in different compositions, shapes, and sizes), and are an alternative to large-scale off-grid energy storage applications and mobility to replace lithium-ion or lead-acid energy storage devices in public transportation, they cannot achieve the desired results using the existing chemistry available for zinc-based energy storage devices.

[0010] Furthermore, most existing zinc-based redox energy storage devices operate based on redox flow battery technology. The electrolyte in these devices needs to be stored in a tank and pumped, allowing a very large amount of electrolyte to circulate through the device on both sides of a membrane that acts as a separator. The chemical potential energy generated during charging is stored in the electrolyte tank. Existing zinc-based flow energy storage devices suffer from dendrite growth problems, especially as the operating current density increases during charging (deposition).

[0011] While patent application US 20180277864 A1 claims to have partially solved the dendrite growth problem, the circulation of the liquid electrolyte remains cumbersome, effectively limiting the use of zinc redox flow batteries in mobile applications and confining them to large, stationary installations. The use of large equipment and the requirements for storing the electrolyte in tanks and pumping it during charging / discharging make the entire setup very expensive.

[0012] Due to limitations in existing zinc redox flow storage devices, efforts have been made to develop zinc redox batteries with non-flowing electrolytes. US5591538A discloses a zinc-bromine redox battery with a non-flowing electrolyte; however, its applications are very limited. Bromine is known for its inherently high corrosiveness, which limits its widespread use as a redox coupler. This corrosiveness leads to low energy efficiency and necessitates special leak-proof arrangements to prevent any form of bromine leakage outside the battery.

[0013] There is a need to explore new possibilities regarding the materials used, the design involved in the manufacturing process, and the scope of improvements to existing technologies to overcome the problems present in existing zinc-based rechargeable redox static energy storage devices, and to improve the overall performance of the energy storage devices and reduce manufacturing costs. Summary of the Invention

[0014] This invention proposes a zinc-based rechargeable redox static energy storage device, which overcomes the limitations of existing zinc-based rechargeable redox static energy storage devices and has the aforementioned desired improved features compared to existing zinc-based rechargeable redox static energy storage devices.

[0015] The zinc-based rechargeable redox static energy storage device according to the present invention includes a cathode pre-injected with a eutectic electrolyte in a ratio between 0.5-1.5:2-5; an anode pre-injected with a eutectic electrolyte in a ratio between 0.5-1.5:2-5; wherein the cathode is connected to a first current collector; wherein the anode is connected to a second current collector; and a separator separating the cathode and the anode, allowing ion exchange to occur between the cathode and the anode through ion permeability.

[0016] The cathode comprises a carbon material-binder composition with a weight ratio maintained between 80-99.9:0.1-20; the anode comprises a carbon material-zinc material-binder composition with a weight ratio maintained between 80-90:10-15.9:0.1-10; wherein the carbon material is selected, alone or in combination, from the group consisting of: conductive carbon black, graphite, carbon particles, carbon nanoparticles, woven or non-woven carbon cloth, carbon felt, carbon paper, carbon rods, and combinations thereof; wherein the binder is selected from the group consisting of PTFE, PVDF, SBR, CMC, and PVA; wherein the zinc material is selected from the group consisting of zinc powder, zinc dust, and zinc foil; wherein the eutectic electrolyte contains one or more inorganic transition metal salts of zinc, selected from zinc chloride, zinc acetate, and methanesulfonic acid. The group consisting of zinc, zinc sulfate, and zinc trifluoromethanesulfonate; one or more metal salts selected from the group consisting of: manganese, nickel, titanium, and copper metals with sulfate anions, methanesulfonate anions, and halogen anions including chlorine and bromine; transition metal ions with anions such as acetate, oxalate, formate, phosphonate, lactate, malate, citrate, benzoate, and ascorbic acid; one or more metal hydroxides selected from the group consisting of sodium hydroxide, potassium hydroxide, aluminum hydroxide, zinc hydroxide, calcium hydroxide, cesium hydroxide, magnesium hydroxide, and iron hydroxide; wherein one or more inorganic transition metal salts of zinc, one or more metal salts, and one or more metal hydroxides are in the range of 0.1-3: The mixture is prepared in a molar concentration range of 0.1-3:0.05-1 with a eutectic solvent comprising one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions, wherein the metal ions are selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X can be selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13.

[0017] The first set of electrical appliances is selected from the group consisting of titanium and carbon materials; and the second set of electrical appliances is selected from the group consisting of titanium, carbon materials and zinc materials.

[0018] The separator used is selected from the group consisting of microporous PVC, microporous polypropylene, absorbent glass pads, and cellulose filter paper. The thickness ratio of the anode to the cathode is in the range of 2-10:1-5. The zinc-based rechargeable redox static energy storage device disclosed in this invention has a C-rate in the range of 0.2-5 and a cycle life in the range of 3000 to 10000. Attached Figure Description

[0019] Figure 1 This is an exploded view of components according to one embodiment of the present invention.

[0020] Figure 2 Cyclic voltammetry curves of the test setup are shown, with a scan rate of 5 mV / s. A pair of well-defined peaks are visible in the possible range of 1–2.2 V. The redox ratio is ~1, indicating a highly reversible reaction.

[0021] Figure 3 The XRD patterns of the cathodes of test devices A and B at 100% and 0% charge states, respectively, after the carbon peak was removed. No obvious peak is observed at 0% SOC, but the titanium current collector peak shows a manganese dioxide peak at 100% SOC.

[0022] Figure 4 The constant current charge-discharge curves of the test setup are shown. The two voltage plateaus around 1.5V and 1.4V represent the charging and discharging processes, respectively.

[0023] Figure 5 The charging and discharging behavior of the test setup is shown under constant current cycling conditions. Both curves show that the discharge capacity increases steadily with increasing cycle life.

[0024] Figure 6 The constant current charge-discharge curves of the test device under constant voltage 1.7V charge-constant current discharge (CV-CC) conditions are shown.

[0025] Figure 7 The constant current charge-discharge curves of the test device are shown at different current rates, namely C / 7, C / 4, 1C, and 5C. High coulombic efficiency and low polarization are observed throughout the current range.

[0026] Figure 8 Cyclic performance—coulombic efficiency and discharge capacity—of the test apparatus prepared at different temperatures of 15°C (lower point) and 30°C (upper point) is shown.

[0027] Figure 9The cycle life and coulombic efficiency of the zinc redox battery test setup at 3C rate are shown. The zinc redox battery exhibits excellent cycle stability. After a long period of cycling, nearly 95% of the maximum discharge capacity is retained.

[0028] Figure 10 The cycle life and coulombic efficiency of the zinc redox battery test setup at a 5C rate are shown. The zinc redox battery exhibits excellent cycle stability even at high rates. Detailed Implementation

[0029] This invention discloses a zinc-based rechargeable redox static energy storage device (1) based on the redox principle. The components used in the preparation of this device (1) are environmentally friendly, non-toxic, and non-flammable. The device according to this invention is recyclable.

[0030] I. Definition

[0031] For the purpose of interpreting the specification and appended claims, the following terms shall be given the meanings listed below: The term "redox" refers to chemical reactions in which oxidation and reduction changes can occur through the loss and gain of electrons, such as Mn. 2+ The ions are oxidized to manganese dioxide, and the manganese dioxide is reduced to Mn. 2+ ion.

[0032] The term "static energy storage device" refers to an energy storage device having an electrolyte or cathode or anode material that is physically non-flowing or non-moving.

[0033] The term "solvent" should refer to a liquid medium that can dissolve other substances.

[0034] "Eutectic electrolyte" refers to an electrolyte solution that contains ions but does not use water as a solvent. It typically contains a eutectic solvent and ions, atoms, or molecules that have lost or gained electrons, and is electrically conductive.

[0035] The term "carbon material" refers to carbon-containing materials or compounds having a carbon content of at least 98%. Examples include, but are not limited to, conductive carbon black, carbon particles, carbon nanoparticles, woven or nonwoven carbon cloth, carbon felt, carbon paper, carbon rods, and combinations thereof.

[0036] A binder refers to a substance that binds two or more materials together. Examples include, but are not limited to, PTFE, PVDF, SBR, CMC, and PVA.

[0037] Zinc materials should refer to various forms of metallic zinc. Examples include, but are not limited to, zinc powder, zinc dust, and zinc foil.

[0038] The term "partition" refers to a permeable membrane between the anode and cathode that allows ion exchange between the electrodes without short-circuiting the device. Examples include, but are not limited to, microporous PVC, microporous polypropylene, absorbent glass pads, and cellulose filter paper.

[0039] The term "current collector" should refer to the material used for electron conduction through electrodes.

[0040] When referring to the composition or concentration of an electrolyte, moles should be based on the total volume of the electrolyte.

[0041] II. Description Various embodiments of the invention are described in detail herein, examples of which are illustrated in the accompanying drawings and described below. It is to be understood that the invention according to this specification is not intended to be limited to these exemplary embodiments. The invention is intended to cover various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention as defined in the claims.

[0042] The zinc-based rechargeable redox static energy storage device according to the present invention includes a cathode pre-injected with a eutectic electrolyte in a ratio between 0.5-1.5:2-5; an anode pre-injected with a eutectic electrolyte in a ratio between 0.5-1.5:2-5; wherein the cathode is connected to a first current collector; wherein the anode is connected to a second current collector; and a separator separating the cathode and the anode, allowing ion exchange to occur between the cathode and the anode through ion permeability.

[0043] In forming the cathode (2), carbon material and binder are uniformly mixed at a weight ratio ranging from 80-99.9:0.1-20. The carbon material-binder composition is injected into a eutectic electrolyte at a weight ratio ranging from 0.5-1.5:2-5 to form a clay-like slurry. The slurry is then shaped into the cathode (2) for use. The cathode (2) prepared in this way is called a "cathode pre-injected with eutectic electrolyte".

[0044] In forming the anode (3), carbon material, zinc material, and binder are uniformly mixed at a weight ratio ranging from 80-90:10-15.9:0.1-10. The carbon material-zinc material-binder composition is injected into a eutectic electrolyte at a weight ratio ranging from 0.5-1.5:2-5 to form a clay-like slurry. Alternatively, the anode (3) is formed by uniformly mixing the carbon material and binder. The carbon material-binder composition is injected into a eutectic electrolyte at a weight ratio ranging from 0.5-1.5:2-5 to form a clay-like slurry. As an alternative to uniformly mixing the zinc material and the carbon material-binder composition, zinc foil is used in proportion to maintain the carbon material-zinc material-binder weight ratio in the range of 80-90:10-15.9:0.1-10. The slurry is shaped into the anode (3) using zinc foil. The carbon material-zinc material-binder composition is shaped into the anode (3) for use. The anode (3) prepared in this way is called "anode pre-injected with eutectic electrolyte".

[0045] The carbon materials used are selected from the group consisting of: conductive carbon black, carbon particles, carbon nanoparticles, woven or nonwoven carbon cloth, carbon felt, carbon paper, carbon rods, and combinations thereof.

[0046] The adhesive used is selected from a group consisting of PTFE, PVDF, SBR, CMC, and PVA.

[0047] The zinc material used is selected from a group consisting of zinc powder, zinc dust, and zinc foil.

[0048] The eutectic electrolyte comprises one or more inorganic transition metal salts of zinc, selected from the group consisting of zinc chloride, zinc acetate, zinc methanesulfonate, zinc sulfate, and zinc trifluoromethanesulfonate; one or more metal salts selected from the group consisting of: manganese, nickel, titanium, and copper metals with sulfate anions, methanesulfonate anions, and halogen anions including chloride and bromine; organic salts of transition metal ions with anions such as acetate, oxalate, formate, phosphonate, lactate, malate, citrate, benzoate, and ascorbate; and one or more metal hydroxides selected from the group consisting of sodium hydroxide, potassium hydroxide, aluminum hydroxide, zinc hydroxide, calcium hydroxide, cesium hydroxide, magnesium hydroxide, and iron hydroxide; wherein the one or more inorganic transition metal salts of zinc, one or more metal salts, and one... One or more metal hydroxides are mixed with a eutectic solvent in a molar concentration range of 0.1-3:0.1-3:0.05-1, wherein the eutectic solvent comprises one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X may be selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13.

[0049] To prepare the eutectic solvent, the following are mixed: one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X is selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of the methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13. After proper mixing, the mixture begins to transform into a liquid eutectic solvent under ambient temperature and pressure. To ensure proper mixing of the components and accelerate the process, the mixture is uniformly heated at temperatures up to 60°C. One or more inorganic transition metal salts of zinc, selected from the group consisting of zinc chloride, zinc acetate, zinc methanesulfonate, zinc sulfate, and zinc trifluoromethanesulfonate; one or more metal salts selected from the group consisting of: manganese, nickel, titanium, and copper metals with sulfate anions, methanesulfonate anions, halogen anions including chlorine and bromine, and transition metal ions with anions such as acetate, oxalate, formate, phosphonate, lactate, malate, citrate, benzoate, and ascorbate; one or more metal hydroxides, selected from the group consisting of sodium hydroxide, potassium hydroxide, aluminum hydroxide, zinc hydroxide, calcium hydroxide, cesium hydroxide, magnesium hydroxide, and iron hydroxide; wherein one or more inorganic transition metal salts of zinc, one or more metal salts, and one or more metal hydroxides are added to a eutectic solvent in a molar concentration range of 0.1-3:0.1-3:0.05-1 and continuously mixed until they are completely dissolved in the eutectic solvent to form a eutectic electrolyte.

[0050] To assemble the zinc-based rechargeable redox static energy storage device (1) according to the present invention, a cathode (2) pre-injected with a eutectic electrolyte and an anode (3) pre-injected with a eutectic electrolyte are arranged, with a partition between them allowing ion exchange between the cathode (2) and the anode (3). The cathode (2) is connected to a first current collector (5) selected from the group consisting of titanium and carbon materials. The anode (2) is connected to a second current collector (6) selected from the group consisting of titanium, carbon, and zinc materials.

[0051] The thickness ratio of the cathode (2) to the anode (3) is in the range of 2-10:1-5.

[0052] The partition (4) used is selected from a group consisting of microporous PVC, microporous polypropylene, absorbent glass pad, and cellulose filter paper.

[0053] The first set of electrical appliances (5) is selected from the group consisting of free titanium and carbon materials, of which the carbon materials are selected from the group consisting of free graphite, woven or non-woven carbon cloth, carbon felt, carbon paper and carbon rod.

[0054] The redox reaction on the cathode (2) side involves manganese ions dissolved in the eutectic electrolyte, which electrodeposit manganese dioxide during charging and dissolve back into the eutectic electrolyte during discharging.

[0055] The redox reaction on the anode (3) side involves zinc ions dissolved in the eutectic electrolyte, which electrodeposit metallic zinc during charging and dissolve back into the eutectic electrolyte during discharging.

[0056] The pre-injection of the eutectic electrolyte into the cathode (2) and anode (3) eliminates the need to store the electrolyte in a tank and pump it into the device (1). Furthermore, pre-injecting the electrolyte into the cathode (2) and anode (3) of the device (1) according to the invention eliminates the need to keep the device (1) idle, which was previously required for uniform immersion of electrodes in existing equipment. High efficiency, long cycle life, 100% DOD and high-speed charge / discharge capability, simple, effective, and economical design, and the use of non-toxic and non-corrosive components ensure the safety and wide applicability of the device according to the invention.

[0057] In a preferred embodiment of the present invention, the complete device (1) is prepared by means of: Preparation of eutectic electrolyte: The eutectic electrolyte was prepared as follows: 2 moles of calcium methanesulfonate, 5 moles of ammonium chloride, and 10 moles of ethylene glycol were combined in a rotating round-bottom flask at 60°C in an oil bath and swirl for approximately 45 minutes to obtain a clear, colorless eutectic solvent. The eutectic solvent was then transferred to a glass bottle. The bottle was placed on a magnetic stirring plate. 1 mole of manganese chloride and 1 mole of zinc chloride were then weighed and slowly added to the eutectic solvent with continuous stirring. The mixture was stirred until all the salts were dissolved. 0.4 g of zinc hydroxide was then added to the mixture and stirred again, producing a slightly pink, transparent eutectic electrolyte. The eutectic electrolyte was then removed from the stirring plate and stored in a glass bottle.

[0058] Preparation of zinc-based rechargeable redox static energy storage device (1): The carbon material-binder composition was prepared by uniformly mixing conductive acetylene black and a binder solution. In the carbon material-binder composition, the weight ratio of carbon to the binder composition was maintained at 99.1:0.9. Liquid-dispersed polytetrafluoroethylene (PTFE) (a non-sticky fluoropolymer) was used as the binder. Diluted isopropanol (20% by volume) was used as the solvent for the PTFE binder. Conductive carbon AB 50 from Polimaxx was mixed with the PTFE solution in a planetary mixer for 1 hour to form a homogeneous clay-like slurry. The clay-like slurry was then spread evenly on a tray. It was then vacuum-dried overnight at 60°C to evaporate the solvent. The carbon material-binder composition was then infused with the aforementioned eutectic electrolyte at a weight ratio of 1:3. Mixing was performed on a vertical milling roller for 30 minutes to form a clay-like slurry. This paste was then repeatedly rolled using a TOB-SG-100L laboratory roller to prepare sheets with controllable thickness. For the cathode (2), the plate thickness is maintained at 1 mm, and for the anode (3), the thickness is 0.5 mm. A thin zinc foil with a thickness of 30 micrometers is placed on a plate with a thickness of 0.5 mm to form the anode. Individual titanium foils are connected to each electrode (cathode 2, anode 3) as current collectors for the two electrodes (cathode 2, anode 3).

[0059] Electrodes with current collectors (cathode 2, anode 3) are assembled together with a polypropylene-based microporous membrane Celgard 3501 serving as a separator (4) between them. The resulting embodiment is referred to as “test apparatus (1)”. Figure 1 This is an exploded view of a preferred embodiment of what is referred to as “test apparatus (1)”.

[0060] Experimental test: The test device (1) was prepared as described above and tested using cyclic voltammetry (CV) on a Biologic VPM3 electrochemical workstation at a scan rate of 5 mV s-1.

[0061] Constant current charging and constant current discharging procedures were used to test the test device (1). The test device (1) was also tested at different C rates of C / 7, C / 4, 1C, and 5C.

[0062] The test apparatus (1) was tested at a voltage ranging from 0.5 to 1.9 volts. The test apparatus (1) was tested using a Neware battery cycler. When the test apparatus (1) was charged, soluble manganese ions in the eutectic electrolyte diffused to the cathode and deposited as solid manganese dioxide on various forms of conductive carbon black, while zinc ions were electrodeposited on the carbon side of the anode. During battery discharge, the uniform manganese dioxide layer deposited on the cathode dissolved into soluble manganese ions in the eutectic electrolyte, while the zinc deposited on the anode dissolved into zinc ions in the eutectic electrolyte.

[0063] Experiment 1 Cyclic voltammograms of the test apparatus (1) were obtained to determine reversibility and stability as a possible use case for zinc redox batteries. The CV of the test apparatus (1) was 1000 cycles from 1V to 2.2V at a scan rate of 5mV / s. These results show that the eutectic electrolyte exhibits predominantly Faraday reactions and is compatible with electrochemical charge-discharge modes.

[0064] The above method was used to prepare the test device (1), and then the test was performed using a constant current program. For manganese dioxide deposition and dissolution, the CV curves of the test device (1) showed comparable oxidation and reduction peaks. A pair of well-defined peaks were observed in the potential range of 0.9–2.2 V. Electrochemical deposition of manganese dioxide from the soluble eutectic electrolyte was attributed to an oxidation peak at 1.7 V, while dissolution of manganese dioxide as Mn was attributed to an oxidation peak. 2+ The ions were reduced to a reduction peak at 1.35 V. The redox ratio was 1, indicating that the process was highly reversible.

[0065] Figure 2 Cyclic voltammetry curves of a zinc-based redox cell are shown, with a scan rate of 5 mV / s. A pair of well-defined peaks are visible in the possible range of 1–2.2 V. The redox ratio is ~1, indicating a highly reversible reaction.

[0066] Experiment 2 To determine the crystal structure of the electrode in 0% charge and 100% charge (SOC) states by X-ray diffraction (XRD, PANalytical) using Cu Ka radiation.

[0067] Two identical test devices, A and B, were prepared using the method described above and both were fully charged.

[0068] The cathode of test device A is removed from the device and tested separately, which is considered to be 100% SOC.

[0069] Test device B is fully discharged at a constant current rate, and the cathode is removed from test device B and tested separately, which is considered to be 0% SOC.

[0070] At 100% SOC, the oxidation product was further confirmed by X-ray diffraction (XRD), revealing a β,γ manganese dioxide with a bilnessite structure belonging to the hexagonal crystal system. Upon discharge to 0% SOC, no manganese dioxide pattern was observed, further confirming the dissolution of manganese dioxide.

[0071] Figure 3The XRD patterns of the cathodes of test devices A and B at 100% and 0% charge states, respectively, after the carbon peak was removed, are shown. No obvious peak is observed at 0% SOC, but the titanium current collector peak is accompanied by a manganese dioxide peak at 100% SOC.

[0072] Experiment 3 In order to determine the performance of the zinc redox battery of the test device (1).

[0073] The test device (1) was prepared using the above method, and the constant current charge-discharge technique described above was used for testing.

[0074] Within the 0.5–1.9 V range, the charge / discharge curves exhibit a highly reversible electrochemical process. Low polarization is characterized by average charge and discharge voltage plateaus of 1.55 V and 1.4 V, respectively. The coulombic efficiency and energy efficiency of the highly reversible electrochemical reaction are approximately >99% and >90%, respectively. Figure 4 The constant current charge-discharge curves of the device are shown. The two voltage plateaus around 1.5V and 1.4V represent the charging and discharging processes, respectively.

[0075] Experiment 4 To determine the effect of constant cycling at a lower C rate of C / 5.

[0076] The test device (1) was prepared using the above method, and the test was performed using the above constant current technique.

[0077] The test setup (1) was tested by cycling at a voltage limit of 0.5 to 1.9 V to investigate the cycling stability at a slow C rate of C / 5. It was shown that the capacity increased after each complete cycle for the first 15 cycles. This indicates that more electrolyte is utilized during long cycling. Figure 5 The charging and discharging behavior of the device (1) under constant current cycling test is shown. Both curves show that the discharge capacity increases steadily with increasing cycle life.

[0078] Experiment 5 To determine the effect of constant voltage charging on the zinc redox battery test apparatus (1).

[0079] The test device (1) was prepared using the above method, and the test was performed using the above constant current technique.

[0080] During constant voltage charging at 1.7V, the soluble Mn in the eutectic electrolyte 2+The ions are oxidized to manganese dioxide and uniformly deposited on the carbon matrix, while zinc electrodeposition occurs simultaneously on the anode. A voltage of 1.7V ensures the success of the electrodeposition reaction and suppresses any other side reactions. Even with a constant voltage charging method, the test device (1) is stable and has a high efficiency of 80%. Figure 6 The constant current charge-discharge curves of the test device (1) under constant voltage 1.7V charge-constant current discharge (CV-CC) conditions are shown.

[0081] Experiment 6 To determine the effect of C rate on zinc redox battery test apparatus (1).

[0082] The test device (1) was prepared using the above method, and the constant current charge-discharge technique described above was used for testing.

[0083] The test device (1) was tested by cycling at different C rates with voltage limits of 0.5–1.9 V to investigate its stability under higher loads. Even at a higher C rate of 5 C, it showed a high energy efficiency of 82%, indicating that the test device (1) has low internal resistance.

[0084] Figure 7 The constant current charge-discharge curves of the device are shown at different current rates, namely C / 7, C / 4, 1C, and 5C. High coulombic efficiency and low polarization are observed throughout the current range.

[0085] Experiment 7 In order to determine the effect of temperature on the capacity of zinc redox battery test apparatus (1).

[0086] The test device (1) was prepared using the above method, and the constant current charge-discharge technique described above was used for testing.

[0087] The test device (1) was tested by cycling at different temperature levels of 15°C and 30°C. It was observed that the capacity increased at higher temperatures compared to lower temperatures. Figure 8 Cyclic performance—coulombic efficiency and discharge capacity—of devices prepared at different temperatures of 15°C (lower point) and 30°C (upper point) are shown.

[0088] Experiment 8 To determine the effects of long-term cycling at different C rates.

[0089] The test device (1) was prepared using the above method, and the test was performed using the above constant current technique.

[0090] The device exhibits good cycle stability at 3C, retaining 95% of its capacity even after 1300 cycles. The device with higher rate capacity at 5C demonstrates a stable cycle life of up to 3500 cycles. Figure 9 The cycle life and coulombic efficiency of the zinc redox battery at a 3C rate are shown. The zinc redox battery exhibits excellent cycle stability. After a long period of cycling, nearly 95% of the maximum discharge capacity is retained. The zinc redox battery demonstrates excellent cycle stability even at high rates. Figure 10 The cycle life and coulombic efficiency of the zinc redox battery at a 5C rate are shown. The zinc redox battery exhibits excellent cycle stability even at high rates.

Claims

1. A zinc-based rechargeable redox static energy storage device (1), characterized in that, include A cathode (2) pre-injected with a eutectic electrolyte; wherein the cathode (2) comprises a carbon material-binder composition, wherein the weight ratio of carbon material to binder in the carbon material-binder composition is maintained between 80-99.9:0.1-20; and the weight ratio of the carbon material-binder composition to the eutectic electrolyte is between 0.5-1.5:2-5. An anode (3) pre-injected with a eutectic electrolyte; wherein the anode (3) comprises a carbon material-zinc material-binder composition, wherein the weight ratio of carbon material to zinc material and binder in the carbon material-zinc material-binder composition is maintained between 80-90:10-15.9:0.1-10; and the weight ratio of the carbon material-zinc material-binder composition to the eutectic electrolyte is between 0.5-1.5:2-5; The cathode (2) is connected to the first current collector (5); The anode (3) is connected to the second current collector (6); A partition (4) separates the cathode (2) and the anode (3), allowing ion exchange to occur between the cathode (2) and the anode (3) through ion permeability; The eutectic electrolyte comprises: One or more inorganic transition metal salts of zinc, selected from zinc chloride, zinc acetate, zinc methanesulfonate, zinc sulfate, and trifluoroethylene. The group consisting of zinc mesylate; One or more metal salts selected from the group consisting of: manganese, nickel, titanium and copper metals with sulfate anions, methanesulfonate anions, and halogen anions including chlorine and bromine; transition metal ions with organic salts of anions such as acetate, oxalate, formate, phosphonate, lactate, malate, citrate, benzoate, and ascorbate. One or more metal hydroxides selected from the group consisting of sodium hydroxide, potassium hydroxide, aluminum hydroxide, zinc hydroxide, calcium hydroxide, cesium hydroxide, magnesium hydroxide, and iron hydroxide; The mixture comprises one or more inorganic transition metal salts of zinc, one or more metal salts, and one or more metal hydroxides in a molar concentration range of 0.1-3:0.1-3:0.05-1 with a eutectic solvent, wherein the eutectic solvent comprises one or more methanesulfonic acid derivatives selected from salts of methanesulfonic acid and various metal ions, wherein the metal ions are selected from the group consisting of manganese, zinc, cerium, nickel, titanium, copper, sodium, potassium, and calcium; one or more ammonium salts having the general formula NH4X, wherein X is selected from the group consisting of chloride, methanesulfonate, acetate, sulfate, trifluoromethanesulfonate, and trimethanesulfonate; and one or more hydrogen bond donors selected from the group consisting of urea, thiourea, glycerol, oxalic acid, acetic acid, ethylene glycol, acetamide, benzamide, adipic acid, benzoic acid, and citric acid; wherein the molar ratio of methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors is in the range of 0.5-3:2-7:8-13.

2. The zinc-based rechargeable redox static energy storage device (1) according to claim 1, characterized in that, The carbon material is selected, alone or in combination, from one or a combination of conductive carbon black, graphite, carbon particles, carbon nanoparticles, woven or nonwoven carbon cloth, carbon felt, carbon paper, and carbon rods. The adhesive is selected from the group consisting of PTFE, PVDF, SBR, CMC, and PVA; The zinc material is selected from the group consisting of zinc powder, zinc dust, and zinc foil.

3. The zinc-based rechargeable redox static energy storage device (1) according to claim 2, characterized in that, The first current collector (5) is selected from the group consisting of titanium and carbon materials; and the second current collector (6) is selected from the group consisting of titanium, carbon materials and zinc materials.

4. The zinc-based rechargeable redox static energy storage device (1) according to claim 3, characterized in that, The partitions used are selected from the following materials, which are selected from the group consisting of microporous PVC, microporous polypropylene, absorbent glass pads, and cellulose filter paper.

5. The zinc-based rechargeable redox static energy storage device (1) according to claim 4, characterized in that, The thickness ratio of the anode to the cathode is in the range of 2-10:1-5.

6. The zinc-based rechargeable redox static energy storage device (1) according to claim 5, characterized in that, It has a charge / discharge rate of 0.2C-5C.

7. The zinc-based rechargeable redox static energy storage device (1) according to claim 6, characterized in that, It has between 3,000 and 10,000 cycles.

8. A method for preparing a zinc-based rechargeable redox static energy storage device (1) as described in any one of claims 1-5, comprising: Preparation of eutectic electrolyte: Methanesulfonic acid derivatives, ammonium salts, and hydrogen bond donors are mixed in a molar ratio of 0.5–3:2–7:8–13 to convert into a liquid eutectic solvent; then one or more inorganic transition metal salts of zinc, one or more metal salts, and one or more metal hydroxides are added to the eutectic solvent in a molar concentration range of 0.1–3:0.1–3:0.05–1 to form a eutectic electrolyte; Mix the carbon material and binder evenly; Injecting eutectic electrolyte forms a clay-like slurry; The slurry is shaped into a cathode (2); The carbon material is uniformly mixed with the zinc material and the binder; Inject eutectic electrolyte to form clay-like slurry; mold it into an anode (3); The cathode (2) is connected to the first current collector (5); the anode (3) is connected to the second current collector (6); The partition (4) separates the cathode (2) and the anode (3), allowing ion exchange to occur between the cathode (2) and the anode (3) through ion permeability.

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