Negative electrode protective layer for zinc-ion battery, manufacturing method therefor, and zinc-ion battery comprising same

Abstract

An embodiment of the present invention provides a negative electrode protective layer comprising a tellurium nanostructure, and a zinc-ion battery comprising same. The negative electrode protective layer according to an embodiment of the present invention improves electrochemical behavior, thereby enabling the provision of a zinc-ion battery with a high energy power density and a higher volumetric energy storage capacity, and introduces flat and dense dendrite growth, thereby enabling the zinc-ion battery to use a thinner separator.

Description

Anode protective layer for zinc-ion batteries, method for manufacturing the same, and zinc-ion batteries comprising the same The present invention relates to a cathode protective layer, and more particularly, to a cathode protective layer for a zinc ion battery that can improve the electrochemical behavior of a zinc ion battery. Battery technology based on rechargeable organic electrolytes is indispensable in modern society, but disposal of these batteries today poses serious ecological and environmental challenges. In addition, lithium-ion batteries (LIBs) are currently being widely used in various fields such as mobile electronic devices, implantable medical devices, grid-level storage applications, and electric vehicles, but the stability of the batteries is still an issue due to the chemical reactivity of the electrolyte composed of metallic lithium, sodium, and organic carbonate ester. Zinc-ion batteries (ZIBs) are being proposed as a viable alternative to replace these lithium-ion batteries and secure renewable energy resources. Zinc-ion batteries (ZIBs) are attracting attention as a next-generation energy storage technology due to their superior characteristics, including safety, long-term cycling performance, environmental friendliness, and high power density. These zinc-ion batteries consist of a zinc anode, an intercalated anode, and a porous separator, and their structure allows zinc ions to migrate during charging and discharging. The use of aqueous electrolytes in ZIBs ensures fire and explosion safety, allows for a flexible manufacturing process in air, and facilitates low-cost production. However, although the zinc cathode of ZIBs plays a role in storing energy through the zinc plating / stripping process, its practical application has been limited due to problems such as corrosion and dissolution of the zinc cathode, limited wettability, and lack of sufficient nucleation sites for zinc plating. Zinc-ion batteries are expected to play a significant role as a future energy storage technology, and efforts are ongoing to develop technologies that can improve the performance of zinc-ion batteries, ensure safety, and achieve price competitiveness. (Patent Document 1) Republic of Korea Patent Publication No. 10-2023-0129894 The present invention provides a zinc ion battery having improved electrochemical behavior and safety by forming a protective layer including tellurium nanobelts on the negative electrode surface of the zinc ion battery as a method for solving the problems of the prior art described above. The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below. In order to achieve the above technical task, one embodiment of the present invention provides a negative electrode protective layer for a zinc ion battery. In an embodiment of the present invention, a cathode protective layer formed on a cathode surface of a zinc ion battery is characterized in that it comprises a tellurium nanostructure. In an embodiment of the present invention, the tellurium nano structure may be a cathode protective layer for a zinc ion battery, characterized in that it comprises a plurality of tellurium nano belts. In an embodiment of the present invention, the cathode protective layer for a zinc ion battery may be characterized by having a nano-network structure in which a plurality of tellurium nano-belts are randomly entangled. In an embodiment of the present invention, the tellurium nano belt may be a cathode protective layer for a zinc ion battery, characterized in that the thickness is 30 nm to 100 nm. In an embodiment of the present invention, the cathode protective layer may be a cathode protective layer for a zinc ion battery, characterized in that the thickness of the cathode protective layer is 0.5 μm to 2 μm. Another embodiment of the present invention provides a zinc ion battery. According to one embodiment of the present invention, a zinc ion battery comprises: a positive electrode; an electrolyte positioned on the positive electrode; a separator formed inside the electrolyte; and a negative electrode positioned on the electrolyte; wherein the negative electrode comprises: a metal layer comprising zinc; and a negative electrode protective layer for a zinc ion battery according to claim 1 formed on at least one surface of the metal layer. In an embodiment of the present invention, the corrosion potential of the negative electrode may be a zinc ion battery characterized by being -0.98 V to -0.97 V. In an embodiment of the present invention, the capacity of the cathode is a current density of 0.3 A g -1 2.0A g -1 344mAh g at one time -1 160mAh g -1 It may be a zinc ion battery characterized by: In an embodiment of the present invention, the positive electrode may be a zinc ion battery characterized in that it comprises manganese oxide. In an embodiment of the present invention, the electrolyte may be a zinc ion battery characterized in that it comprises zinc sulfate and manganese sulfate. Another embodiment of the present invention provides a method for manufacturing a cathode protective layer for a zinc ion battery. In an embodiment of the present invention, the method comprises the steps of: dissolving polyvinylpyrrolidone in deionized water and then adding sodium tellurite (Na2TeO3) to prepare a sodium tellurite solution; adding hydrazine and ammonia water to the sodium tellurite solution to prepare a mixed solution; heating the mixed solution to react to prepare a tellurium solution; and cooling and drying the tellurium solution. In an embodiment of the present invention, the method may be a method for manufacturing a negative electrode protective layer for a zinc ion battery, characterized in that the heating is performed in a temperature range of 160°C to 200°C. According to an embodiment of the present invention, there is an effect of significantly improving the energy storage performance of a zinc ion battery by introducing a protective layer comprising a tellurium nanostructure onto the negative electrode surface of the zinc ion battery. Specifically, the zinc-ion battery cathode protective layer according to the present invention has the effect of preventing corrosion and dissolution of zinc, improving surface protection, providing numerous nucleation sites for zinc plating, thereby increasing the electrode surface area and nucleation sites for zinc plating, and improving electrode wettability due to the presence of tellurium nanobelts on the cathode surface, thereby improving the diffusion behavior of ions, and ultimately improving the energy storage performance of the zinc-ion battery. The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims. Figure 1 is a flow chart schematically illustrating a method for manufacturing a cathode protective layer for a zinc ion battery according to one embodiment of the present invention. Figure 2 is a conceptual diagram illustrating a method for manufacturing a cathode protective layer for a zinc ion battery according to one embodiment of the present invention. Figure 3 is a drawing showing an XRD pattern of an example of manufacturing a negative electrode protective layer for a zinc ion battery of the present invention. Figure 4 is a drawing showing a Raman spectrum according to Raman spectroscopy of a negative electrode protective layer for a zinc ion battery of the present invention. Figure 5 is a drawing showing the results of AFM measurement of a tellurium nanobelt in a cathode protective layer of the present invention. Figure 6 is a drawing showing the results of AFM measurement of a tellurium nanobelt in a cathode protective layer of the present invention. Figure 7 is a drawing showing the results of AFM measurement of a tellurium nanobelt in a cathode protective layer of the present invention. Figure 8 is a drawing showing the TEM structure and morphology results of a tellurium nanobelt in the cathode protective layer of the present invention. Figure 9 is a drawing showing the TEM structure and morphology results of a tellurium nanobelt in the cathode protective layer of the present invention. Figure 10 is a photograph showing bare Zn and TeNB-Zn cathodes applied as cathodes of a zinc ion battery. Figure 11 shows an SEM image of the TeNB-Zn cathode of a zinc ion battery. Figure 12 shows an SEM image of the TeNB-Zn cathode of a zinc ion battery. Figure 13 shows a cross-sectional SEM image of the TeNB-Zn cathode of a zinc ion battery. Figure 14 shows a cross-sectional SEM image of the TeNB-Zn cathode of a zinc ion battery. Figure 15 shows EDS mapping data of the TeNB-Zn cathode of a zinc ion battery. Figure 16 is a diagram showing the results of evaluating the cycle stability and voltage hysteresis of bare Zn and TeNB-Zn cathodes using a symmetric zinc-zinc cell. Figure 17 is a diagram showing the nucleation overvoltage results of bare Zn and TeNB-Zn cathodes using a symmetric zinc-zinc cell. Figure 18 is a graphical representation of the role of the tellurium nanobelt protective layer in mitigating cathode surface dendrite growth during zinc plating. Figure 19 is a drawing showing dendrite growth observed on a bare Zn negative electrode of a zinc ion battery using a stereomicroscope. Figure 20 is a drawing showing dendrite growth observed under a stereomicroscope on a cathode including a tellurium nanobelt protective layer of a zinc ion battery. Figure 21 shows the LSV measurement results of bare Zn and TeNB-Zn cathodes. Figure 22 shows the results of corrosion potential measurements of bare Zn and TeNB-Zn cathodes. Figure 23 shows the differential current curve results of bare Zn and TeNB-Zn cathodes. Figure 24 shows the contact angle measurement results of the bare Zn cathode. Figure 25 shows the contact angle measurement results of the TeNB-Zn cathode. Figure 26 shows the Nyquist plots of zinc ion batteries containing bare Zn and TeNB-Zn cathodes. Figure 27 shows the Warburg impedance coefficient values ​​of zinc ion batteries including bare Zn and TeNB-Zn cathodes. Figure 28 shows the zinc ion diffusion coefficient values ​​of zinc ion batteries including bare Zn and TeNB-Zn cathodes. Figure 29 shows CV curves of zinc ion batteries containing bare Zn and TeNB-Zn cathodes. Figure 30 shows the rate performance at various current densities of zinc ion batteries containing bare Zn and TeNB-Zn cathodes. Figure 31 shows the energy density and power density values ​​of bare Zn and TeNB-Zn cathodes. Figure 32 shows the energy density and power density values ​​of bare Zn and TeNB-Zn cathodes. Figure 33 shows the results of analysis of the cathode surface using CLSM after charging the bare Zn cathode. Figure 34 shows the results of analysis of the cathode surface using CLSM after charging the TeNB-Zn cathode. Figure 35 shows the SEM analysis results after the charge / discharge process of a zinc ion battery including a bare Zn cathode. Figure 36 shows the SEM analysis results after the charge / discharge process of a zinc ion battery including a bare Zn cathode. Figure 37 shows the SEM analysis results after the charge / discharge process of a zinc ion battery including a TeNB-Zn cathode. Figure 38 shows the SEM analysis results after the charge / discharge process of a zinc ion battery including a TeNB-Zn cathode. Figure 39 shows the cathode surface after discharge of a zinc ion battery including a bare Zn cathode. Figure 40 shows the cathode surface after discharge of a zinc ion battery including a bare Zn cathode. Figure 41 shows the cathode surface after discharge of a zinc ion battery including a TeNB-Zn cathode. Figure 42 shows the cathode surface after discharge of a zinc ion battery including a TeNB-Zn cathode. Figure 43 shows the differences in the zinc plating processes of bare Zn and TeNB-Zn cathodes. Figure 44 shows the long-term cycle test results of bare Zn and TeNB-Zn cathodes. Figure 45 shows the results of SEM analysis of the cross-section of the bare Zn cathode after a long-term cycle test. Figure 46 shows the results of SEM analysis of the cross-section of the TeNB-Zn cathode after a long-term cycle test. Figure 47 shows XRD analysis data of the cathodes after long-term cycle tests of bare Zn and TeNB-Zn cathodes. Figure 48 is a photograph of a pouch-type cell made of a zinc ion battery including a bare Zn cathode connected to a propeller. Figure 49 is a photograph of a pouch-type cell made of a zinc ion battery including a TeNB-Zn cathode connected to a propeller. Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention can be implemented in various different forms and is therefore not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar parts have been designated with similar reference numerals throughout the specification. Throughout the specification, when a part is said to be "connected (connected, contacted, or coupled)" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" with another part in between. Furthermore, when a part is said to "include" a component, this does not exclude other components, but rather implies that it may include other components, unless otherwise specifically stated. The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. A cathode protective layer for a zinc ion battery according to one embodiment of the present invention is described. Much research has been conducted to improve the performance of existing zinc-ion batteries, and zinc-ion batteries are expected to play a very important role as a future energy storage technology. In order to fully utilize the potential of zinc anodes, research on the use of carbon, ceramics, polymers, metals, etc. is receiving attention, and the present invention applies tellurium nanostructures, which have not been used in the past in zinc ion batteries, as a protective layer of the anode. Specifically, tellurium (Te), discovered by Muller in 1782, has a narrow band gap (0.35 eV) and high electrical conductivity (2 × 10 2 S m -1 ) and has the potential to be used as a zinc anode protection material for zinc-ion batteries. This high electrical conductivity enhances electrochemical activity, increases the number of active species, and ensures rapid processing during the zinc plating / stripping process. Furthermore, tellurium's chemical stability can address corrosion and dissolution issues at the zinc anode. In addition, in an embodiment of the present invention, the one-dimensional nanobelt structure of the tellurium nanostructure can efficiently promote electron movement during the charging and discharging process of a zinc ion battery. Accordingly, the cathode protective layer for a zinc ion battery according to one embodiment of the present invention is characterized in that it is formed on the cathode surface of a zinc ion battery and is configured to include a tellurium nanostructure. In an embodiment of the present invention, the tellurium nanostructure is a nanostructure composed of tellurium, and may have various shapes such as spherical or linear, and most preferably, may be a nanostructure including a plurality of tellurium nanobelts. At this time, the tellurium nano belt refers to a belt-shaped nano structure composed of tellurium (Te) whose length is greater than its width. In particular, a plurality of tellurium nanobelts constituting the above tellurium nanostructure can form a randomly entangled nanonetwork structure, and this nanonetwork structure can serve as a site for evenly distributing zinc during the charging process in a zinc-ion battery, thereby inducing an improvement in the performance of the battery. At this time, the thickness of the tellurium nano belt may be 30 nm to 100 nm, and may be about 50 nm. The thickness of the negative electrode protective layer for the zinc ion battery may be 0.5 μm to 2 μm, and preferably may be formed on the surface of the zinc metal layer with a thickness of 1 μm. Next, another embodiment of the present invention provides a zinc ion battery. According to one embodiment of the present invention, a zinc ion battery comprises: a positive electrode; an electrolyte positioned on the positive electrode; a separator formed inside the electrolyte; and a negative electrode positioned on the electrolyte; wherein the negative electrode comprises: a metal layer comprising zinc; and a negative electrode protective layer for a zinc ion battery according to claim 1 formed on at least one surface of the metal layer. A zinc ion battery assembled using a zinc anode coated with a cathode protective layer including a tellurium nanobelt, which is one component of the present invention, can exhibit improved performance such as increased capacity, improved rate performance, and extended lifespan, and such improvements are attributed to the provision of numerous nucleation sites for zinc plating, effective suppression of random dendrite formation, and prevention of zinc corrosion and dissolution. In the above zinc ion battery, the positive electrode may use a positive electrode material commonly used in the art, and may be composed of, for example, manganese oxide. In the above zinc ion battery, the electrolyte may be composed of at least one selected from the group consisting of polyvinyl alcohol (PVA), zinc sulfate (ZnSO4), manganese sulfate (MnSO4), vanadium sulfate (VOSO4), phosphoric acid (H3PO4), sulfuric acid (H2SO4), sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2), and may be composed of, but is not limited to, manganese sulfate and zinc sulfate. In the zinc-ion battery, a separator may be placed between the negative electrode and the positive electrode, and the separator may include at least one selected from the group consisting of a porous film, a nonwoven fabric, and a woven fabric made of a material such as a polyolefin resin such as polyethylene or polypropylene, a fluororesin, or a nitrogen-containing aromatic polymer. At this time, the thickness of the separator is preferably thinner as long as mechanical strength is maintained, as this increases the volumetric energy density of the battery and reduces the internal resistance. Specifically, the thickness of the separation membrane may be, for example, about 5 µm to 200 µm, and preferably, about 5 µm to 40 µm. Finally, another embodiment of the present invention provides a method for manufacturing a cathode protective layer for a zinc ion battery. Figure 1 is a flow chart schematically illustrating a method for manufacturing a cathode protective layer for a zinc ion battery according to one embodiment of the present invention. A method for manufacturing a negative electrode protective layer for a zinc ion battery according to one embodiment of the present invention is characterized by including the steps of: dissolving polyvinylpyrrolidone (PVP) in deionized water and then adding sodium tellurite (Na2TeO3) to prepare a sodium tellurite solution (S100); adding hydrazine (N2H4) and ammonia water to the sodium tellurite solution to prepare a mixed solution (S200); heating the mixed solution to react to prepare a tellurium solution (S300); and cooling and drying the tellurium solution (S400). At this time, the heating can be performed at a temperature range of 160°C to 200°C, and preferably 180°C. At this time, a process of cooling the tellurium solution and then washing it with deionized water may be further included. In addition, it may be appropriate to disperse the tellurium solution prepared in the above step (S400) in a solvent such as ethanol, coat it on the zinc negative electrode of a zinc ion battery, and then dry it. Hereinafter, the present invention will be described in more detail through manufacturing examples, comparative examples, and experimental examples. However, the present invention is not limited to the following manufacturing examples and experimental examples. Manufacturing Example 1: Manufacturing of a cathode protective layer for a zinc ion battery Figure 2 is a conceptual diagram illustrating a method for manufacturing a cathode protective layer for a zinc ion battery according to one embodiment of the present invention. As shown in Fig. 2, a negative electrode protective layer for a zinc ion battery according to one embodiment of the present invention was manufactured. First, 0.5 g of polyvinylpyrrolidone was completely dissolved in deionized water, and then a solution containing 0.45 mmol of tellurium hydroxide (Na2TeO3) was added to the PVP solution. When the component was completely dissolved, the solution turned transparent. Afterwards, a certain amount of hydrazine (N2H4) and ammonia water were added to the solution respectively and maintained for 5 minutes. The resulting mixture was then transferred to a Teflon-lined autoclave and heated at 180°C for 30 hours. After the reaction was complete, the Teflon-lined vessel was allowed to cool naturally to room temperature, and the resulting tellurium solution was washed three times with deionized water using a centrifuge. Finally, the washed solution was dispersed in ethanol. Manufacturing Example 2: Manufacturing of zinc-ion batteries (ZIBs) To apply a protective layer to the zinc ion battery negative electrode, the tellurium solution prepared in Preparation Example 1 was coated on the surface of zinc foil using a drop casting method. After coating, the foil was dried in an oven at 80°C. The cathode slurry was prepared by mixing manganese oxide, polyvinylidene fluoride, and carbon black in a mass ratio of 8:1:1 in a naphtharium methylpropionic acid (NMP) solvent. The anode was prepared by coating a manganese oxide slurry on a graphite current collector and drying it. The zinc ion battery of the manufacturing example is composed of a TeNB-Zn cathode, a manganese oxide anode, and a glass fiber separator. At this time, the zinc ion battery is filled with an aqueous electrolyte solution containing 2 M zinc sulfate (ZnSO4) and 0.1 M manganese sulfate (MnSO4). Additionally, as a comparative example, a zinc ion battery including a zinc cathode without a protective layer was also fabricated. Hereinafter, a zinc cathode without a protective layer is referred to as a bare Zn cathode, and a zinc cathode including a cathode protective layer of the present invention is referred to as a TeNB-Zn cathode. Experimental Example 1: Morphological, structural, and crystallographic characteristics of the cathode protective layer X-ray diffraction patterns of tellurium nanobelts within the cathode protective layer were obtained using an X-ray diffractometer equipped with a copper Kα source. Figure 3 is a drawing showing an XRD pattern of an example of manufacturing a negative electrode protective layer for a zinc ion battery of the present invention. Referring to the above Figure 3, the peaks observed in the XRD pattern confirm the presence of highly crystalline hexagonal tellurium, which is consistent with previous studies. Figure 4 is a drawing showing a Raman spectrum according to Raman spectroscopy of a negative electrode protective layer for a zinc ion battery of the present invention. In the above Fig. 4, three active modes were observed in the Raman spectroscopy of the tellurium nanobelt (Fig. 2b), (E1 mode (~90.8 cm -1 ), A1 mode (~120.3 cm -1 ), E2 mode (~140.7 cm -1 ), which is consistent with existing literature. FIGS. 5 to 7 are drawings showing the results of AFM (Atomic Force Microscope) measurements of tellurium nanobelts in the cathode protective layer of the present invention. As shown in the above Figures 5 to 7, the thickness of the tellurium nanobelt generated as a result of AFM measurement was approximately 50 nm. The morphology of the cathode protective layer was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and Raman spectroscopy was performed using a laser wavelength of 532.1 nm. FIG. 8 and FIG. 9 are drawings showing the TEM structure and morphology results of the tellurium nanobelt in the cathode protective layer of the present invention. As shown in the above Figures 8 and 9, tellurium is composed of individual helical chains of tellurium atoms.

[0001] It exhibits a hexagonal crystal structure with chiral chains aligned in the direction, and the layers are stacked through weak van der Waals interactions. The TEM image of the nanobelt shows a defect-free 1D structure, and the interlayer lattice is estimated to be approximately 0.6 nm, which is consistent with existing literature. Selected Area Electron Diffraction (SAED) patterns were focused along the

[0010] plane, and clear single crystal patterns corresponding to the (003), (101), and (110) lattice planes were observed, which is also consistent with existing literature. Experimental Example 2: Structure of a zinc-ion battery cathode coated with a cathode protective layer The thickness of the tellurium nanobelts on the cathode was measured using atomic force microscopy (AFM). Figure 10 is a photograph showing bare Zn and TeNB-Zn cathodes applied as cathodes of a zinc ion battery. Referring to the above Fig. 10, the photographs of bare Zn and TeNB-Zn cathodes applied as cathodes of zinc ion batteries show that tellurium is uniformly coated on the surface of the zinc anode without any space. Figures 11 and 12 show SEM images of the TeNB-Zn cathode of a zinc ion battery. The above Figures 11 and 12 show the structure of a TeNB-Zn cathode having a network structure and a thickness of 50-60 nm. Figures 13 and 14 show cross-sectional SEM images of the TeNB-Zn cathode of a zinc ion battery, and the cross-sectional SEM images of the TeNB-Zn cathode show a coating thickness of about 1 μm on the surface of the zinc cathode. Figure 15 shows EDS mapping data of the TeNB-Zn cathode of a zinc ion battery, and the presence of a uniform tellurium coating layer was confirmed through the EDS mapping data. Experimental Example 3: Evaluation of cycling stability and voltage hysteresis Galvanic measurements were performed to evaluate the electrochemical stability and voltage hysteresis of bare Zn and TeNB-Zn cathodes using a symmetric Zn||Zn cell. These measurements were performed at a current density of 2.0 mA cm -2 was performed for 500 hours. CV measurements were performed in the voltage range of 1.0 to 1.9 V with a resolution of 0.5 mV s -1 was performed at an injection speed of . The speed performance was 0.3 to 2.0 A g within this voltage range. -1 was observed in the range of 1.0 A g. The cycle test was performed at -1 It was performed up to 200 times at a current density of . Figure 16 is a diagram showing the results of evaluating the cycle stability and voltage hysteresis of bare Zn and TeNB-Zn cathodes using a symmetric zinc-zinc cell. Figure 17 is a diagram showing the nucleation overvoltage results of bare Zn and TeNB-Zn cathodes using a symmetric zinc-zinc cell. As in the above Figure 16, to monitor the voltage change over time, a current density of 2.0 mA cm -2 Voltage profiles were recorded during cycling for 500 hours. During cycling, rapid voltage spikes and drops were observed, indicating uncontrolled zinc dendrite formation on the zinc anode surface, necessitating a protective layer. In contrast, the TeNB-Zn cathode exhibited consistent and minimized voltage polarization throughout the cycling process, suggesting that the introduced protective layer helped control zinc dendrite growth. Additionally, as shown in Fig. 17 above, the nucleation overvoltages of the bare Zn and TeNB-Zn cathodes in the initial cycle were 90 and 37 mV, respectively. Figure 18 is a graphical representation of the role of the tellurium nanobelt protective layer in mitigating cathode surface dendrite growth during zinc plating. Figure 19 is a drawing showing dendrite growth observed on a bare Zn negative electrode of a zinc ion battery using a stereomicroscope. Figure 20 is a drawing showing dendrite growth observed under a stereomicroscope on a cathode including a tellurium nanobelt protective layer of a zinc ion battery. Figure 18 shows that introducing tellurium nanobelts with a one-dimensional network structure as a protective layer can promote uniform zinc growth due to the abundant nucleation sites and low nucleation barrier. In the above Figure 19, the bare Zn cathode exhibits a rough surface as zinc plating progresses, suggesting random growth of dendrites that may cause electrical short circuits. On the other hand, even after zinc plating for 120 minutes in the above-described Fig. 20, the TeNB-Zn cathode exhibited a smooth surface, indicating that the tellurium nanobelts acted as a protective layer and effectively suppressed dendrite growth. Experimental Example 4: Evaluation of hydrogen generation reaction and corrosion prevention properties Next, the hydrogen evolution reaction (HER) and corrosion prevention properties of the prepared cathode were evaluated using a three-electrode system. Figure 21 shows the LSV measurement results of bare Zn and TeNB-Zn cathodes. Figure 22 shows the results of corrosion potential measurements of bare Zn and TeNB-Zn cathodes. As in the above figure 21, 5 mV s -1 LSV measurements performed at injection rates of 100 μm showed a rapid increase in the anodic current density of the zinc cathode. In contrast, the TeNB-Zn cathode showed a much slower increase in current density. In addition, as shown in the above Fig. 22, the corrosion potential of the zinc cathode increases from -0.990 V to -0.976 V when the tellurium nanobelt is used as a protective layer on the zinc cathode, indicating that the presence of the tellurium nanobelt as a protective layer on the cathode can effectively suppress the corrosion reaction. Experimental Example 5: Investigation of Zinc Ion Diffusion Behavior The diffusion behavior of zinc ions adsorbed on the zinc surface was investigated using differential current curves collected at fixed potentials. Figure 23 shows the differential current curve results of bare Zn and TeNB-Zn cathodes. The current density of the bare Zn cathode did not stabilize for a long time due to the two-dimensional diffusion of zinc ions on the zinc cathode surface. In contrast, the TeNB-Zn cathode exhibited a stable current density after a short deposition time of approximately 55 s. This is likely because the tellurium nanobelts protected the zinc electrode, suppressing the random diffusion behavior of zinc ions through a three-dimensional diffusion effect. These results demonstrate the excellent chemical stability of the tellurium nanobelts introduced into the TeNB-Zn cathode, which contributes to suppressing HER and corrosion and improving diffusion behavior. Experimental Example 6: Wetability Evaluation Contact angle measurements were performed to evaluate the wettability of the prepared bare Zn and TeNB-Zn cathodes. Figure 24 shows the contact angle measurement results of a bare Zn cathode, and Figure 25 shows the contact angle measurement results of a TeNB-Zn cathode. Referring to FIGS. 24 and 25 above, the TeNB-Zn cathode exhibited a lower contact angle (92°) than the zinc anode (113°). This is because tellurium nanobelts with a one-dimensional network structure were used as a protective layer, and the improved wettability can enhance the ion transport capability at the cathode-electrolyte interface. Figure 26 shows the Nyquist plot of a zinc ion battery including bare Zn and TeNB-Zn cathodes. To measure the Warburg impedance, we focused on the low-frequency region. Compared to the zinc anode, the TeNB-Zn anode exhibited a lower Warburg impedance. Figure 27 shows the Warburg impedance coefficient values ​​of zinc ion batteries including bare Zn and TeNB-Zn cathodes. Figure 28 shows the zinc ion diffusion coefficient values ​​of zinc ion batteries including bare Zn and TeNB-Zn cathodes. As shown in Fig. 27, the calculated Warburg impedance coefficient (σw) values ​​of the bare Zn cathode and the TeNB-Zn cathode are shown. This value is the total electrode resistance (R e ), gas constant (R), temperature (T), electrode area (A), number of electrons per molecule (n), Faraday constant (F), molar concentration of zinc ions (C), etc. were calculated using Equations 1 and 2 above, taking into account various variables. The calculated σ and w values ​​of the Zn cathode and TeNB-Zn cathode were 16.2 and 7.1, respectively. In addition, as shown in the above Figure 28, the calculated zinc ion diffusion coefficient (D) values ​​of the bare Zn cathode and the TeNB-Zn cathode are 0.9 and 4.4 × 10, respectively. -17 cm 2 s -1 It was. These results indicate that the ion diffusion behavior observed in the TeNB-Zn cathode may be attributed to the enhanced electrode wettability resulting from the presence of tellurium nanobelts with a one-dimensional network structure on the cathode surface. Experimental Example 7: CV Curve Figure 29 shows CV curves of zinc ion batteries containing bare Zn and TeNB-Zn cathodes. The above figure 29 is 0.5 mV s -1 The measured CV curves of the sample are plotted at a scanning rate of and a potential range of 1.0 to 1.9 V. The presence of redox peaks or bumps in the CV curves indicates the Faradic process associated with the electrochemical reactions occurring in zinc-ion batteries. In particular, these peaks correspond to the reaction Zn ↔ 2e + Zn 2+ It shows the plating and peeling of zinc ions at the cathode, which is expressed as . This corresponds to the characteristics commonly observed in zinc ion batteries. Furthermore, the TeNB-Zn cathode exhibits a larger CV area than the zinc cathode, providing more electrochemically active sites for zinc plating. In conclusion, the lower Warburg impedance coefficient and higher zinc ion diffusion coefficient demonstrate that introducing tellurium nanobelts into zinc-ion battery cathodes improves ion diffusion behavior. Additionally, the TeNB-Zn cathode appears to be a promising candidate for enhanced zinc-ion battery performance by providing more electrochemically active sites. Experimental Example 8: Speed ​​Performance Experiment Wide current density range (0.3 to 2.0 A g -1 ) was used to conduct rate performance tests on zinc-ion batteries. Figures 30 and 31 show the rate performance at various current densities of zinc ion batteries containing bare Zn and TeNB-Zn cathodes. Current density is 0.3 A g -1 The capacities of bare Zn cathode and TeNB-Zn cathode were 226 mAh g, respectively. -1 and 344 mAh g -1 , it can be seen that the interface engineering between the zinc anode and the aqueous electrolyte is important for achieving improved energy storage performance. Nucleation sites for zinc plating on a zinc anode are limited, and corrosion of the zinc limits the energy storage potential of the anode. To address this issue, this study introduced tellurium nanobelts with a one-dimensional network structure to increase nucleation sites for zinc plating and improve zinc corrosion resistance. As a result, a high current density of 2.0 A g was achieved. -1 In the case of TeNB-Zn cathode, the capacity is 160 mAh g -1 , which represents the capacity of a bare Zn cathode (69 mAh g -1 ) corresponds to a higher value. As can be seen in Fig. 31 above, the improved rate performance of the TeNB-Zn cathode is superior to that of previously reported zinc-ion batteries. Experimental Example 9: Energy Density and Power Density Figure 32 shows the energy density and power density values ​​of bare Zn and TeNB-Zn cathodes. 270 ~ 1,800 W kg -1 The energy density of TeNB-Zn cathode in the power density range is 310~144 Wh kg -1 , it shows higher performance than previously reported zinc ion cathodes using manganese oxide cathodes, and this improvement in energy storage performance is attributed to the protective layer containing tellurium nanobelts with a one-dimensional network structure. The tellurium-based protective layer offers excellent chemical stability and numerous nucleation sites for zinc plating, enabling stable electrochemical reactions and enhanced ion diffusion behavior. Furthermore, the one-dimensional network structure of the protective layer facilitates electron transport during charging and discharging. Experimental Example 10: CLSM Analysis To clarify the role of the protective layer applied to the TeNB-Zn cathode, the surface of the cathode was analyzed using confocal laser scanning microscopy (CLSM) after charging the cathode. Figure 33 shows the results of CLSM analysis of the cathode surface after charging a bare Zn cathode. Figure 34 shows the results of CLSM analysis of the cathode surface after charging a TeNB-Zn cathode. In the above Fig. 33, the bare Zn cathode after charging exhibited a rough surface with a roughness of approximately 18 μm, indicating random dendrite growth. On the other hand, the TeNB-Zn cathode exhibited a flat surface even after charging, as shown in the above Fig. 34, demonstrating uniform zinc plating. Experimental Example 11: Charge-Discharge Behavior Analysis To further analyze the charge and discharge behavior of the prepared positive electrode, SEM analysis was performed after each process. Figures 35 and 36 show the SEM analysis results after the charge / discharge process of a zinc ion battery including a bare Zn negative electrode. Figures 37 and 38 show SEM analysis results after a charge / discharge process of a zinc ion battery including a TeNB-Zn cathode. Figures 39 and 40 show the cathode surface after discharge of a zinc ion battery including a bare Zn cathode. Figures 41 and 42 show the cathode surface after discharge of a zinc ion battery including a TeNB-Zn cathode. After charging, randomly grown dendrites were observed in the bare Zn cathode as shown in FIGS. 35 and 36, and zinc plating filling the space between tellurium nanobelts was observed in the TeNB-Zn cathode as shown in FIGS. 37 and 38. After discharge, ZHS was observed as a by-product on the surface of the bare Zn cathode as shown in FIGS. 39 and 40, whereas the TeNB-Zn cathode maintained its initial network structure as shown in FIGS. 41 and 42. Figure 43 illustrates the differences in the zinc plating processes of bare Zn and TeNB-Zn cathodes. As illustrated in Figure 43, the protective layer comprising one-dimensional tellurium nanobelts not only provides nucleation sites for stable zinc plating but also acts as a zinc corrosion and dendrite formation inhibitor. This demonstrates that the tellurium nanobelt protective layer plays a crucial role in achieving stable zinc plating and improving the overall performance of TeNB-Zn cathodes. Experimental Example 12: Cycle Test Long-term cycle tests were conducted to verify the reliability and suitability of the battery under various real-world conditions. Figure 44 shows the long-term cycle test results of bare Zn and TeNB-Zn cathodes. The above figure 44 shows that the current density is 1.0 A g -1 The results of long-term cycling tests performed on bare Zn and TeNB-Zn anodes are shown. The bare Zn anode showed a rapid capacity decrease due to the decomposition of the zinc anode during the charge and discharge process, and after 200 cycles, the capacity was 56 mAh g -1 Although the capacity decreased, the tellurium nanobelt Zn cathode showed a slower capacity decrease. This can be interpreted as a result of the tellurium nanobelt effectively acting as a protective layer on the zinc surface. To investigate this in more detail, cross-sections of the cathode were analyzed by SEM after charge and discharge tests. Figure 45 shows the results of SEM analysis of the cross-section of the bare Zn cathode after a long-term cycle test. Figure 46 shows the results of SEM analysis of the cross-section of the TeNB-Zn cathode after a long-term cycle test. As shown in the above Figures 45 and 46, unlike the TeNB-Zn cathode, corrosion occurred in the bare Zn cathode, and ZHS byproducts were detected on the surface. Figure 47 shows XRD analysis data of bare Zn and TeNB-Zn cathodes after long-term cycling tests. Zinc sulfate-based electrolytes, forming ZHS, were observed on the bare Zn cathode. In contrast, no such byproducts were observed on the TeNB-Zn cathode. SEM and XRD results after charge and discharge demonstrate that the tellurium nanobelts remain intact on the TeNB-Zn cathode, inhibiting zinc corrosion and dissolution, thereby enhancing the lifespan and performance of the cathode. Experimental Example 13: Practicality Evaluation To evaluate the practicality of the cathode, a ion battery fabricated using existing bare Zn and TeNB-Zn cathodes was connected to a propeller using a pouch-type cell. Figure 48 is a photograph of a pouch-shaped cell made of a zinc-ion battery including a bare Zn cathode connected to a propeller. Figure 49 is a photograph of a pouch-shaped cell made of a zinc-ion battery including a TeNB-Zn cathode connected to a propeller. In the above Figures 48 and 49, the TeNB-Zn battery showed a longer power supply time and improved capacity compared to the conventional zinc battery. According to the experimental examples described above, it is shown that a zinc anode using the tellurium structure of the present invention as a protective layer can improve the energy storage performance of a zinc ion battery. Specifically, the capacity of the TeNB-Zn anode is 0.3 to 2.0 A g at a current density. -1 344 to 160 mAh g at one time -1 , and after 200 charges, the cathode was at 107 mAh g -1 showed the capacity of . This is because the cathode protective layer of the present invention prevents corrosion and dissolution of zinc and improves surface protection, provides numerous nucleation sites for zinc plating, thereby increasing the electrode surface area and nucleation sites for zinc plating, and improves electrode wettability due to the presence of tellurium nanobelts on the cathode surface, thereby improving the diffusion behavior of ions. The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner. The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. In the cathode protective layer formed on the cathode surface of a zinc ion battery, A cathode protective layer for a zinc ion battery, characterized in that it comprises a tellurium nanostructure.

2. In paragraph 1, A cathode protective layer for a zinc ion battery, characterized in that the above tellurium nano structure is composed of a plurality of tellurium nano belts.

3. In paragraph 2, A cathode protective layer for a zinc ion battery, characterized in that the above tellurium nano structure has a nano network structure in which a plurality of tellurium nano belts are randomly entangled.

4. A cathode protective layer for a zinc ion battery, characterized in that the thickness of the tellurium nano belt is 30 nm to 100 nm.

5. In paragraph 2, A cathode protective layer for a zinc ion battery, characterized in that the thickness of the cathode protective layer is 0.5 μm to 2 μm.

6. A zinc ion battery comprising: a cathode; an electrolyte positioned on the cathode; a separator formed inside the electrolyte; and a cathode positioned on the electrolyte; The above cathode is, A metal layer comprising zinc; and a cathode protective layer for a zinc ion battery according to claim 1 formed on at least one surface of the metal layer. A zinc ion battery characterized by including a.

7. In paragraph 6, A zinc ion battery, characterized in that the corrosion potential of the cathode is -0.98 V to -0.97 V.

8. In paragraph 6, The capacity of the above cathode is a current density of 0.3A g -1 2.0A g inland -1 344mAh g at one time -1 Battery 160mAh g -1 A zinc ion battery characterized by:

9. In paragraph 6, A zinc ion battery, characterized in that the positive electrode is composed of manganese oxide.

10. In paragraph 6, A zinc ion battery, characterized in that the electrolyte comprises zinc sulfate and manganese sulfate.

11. A step of preparing a sodium tellurite solution by dissolving polyvinylpyrrolidone in deionized water and adding sodium tellurite (Na2TeO3); A step of preparing a mixed solution by adding hydrazine and ammonia water to the above sodium tellurite solution; A step of producing a tellurium solution by heating and reacting the above mixed solution; and A method for manufacturing a cathode protective layer for a zinc ion battery, characterized by comprising the steps of cooling and drying the tellurium solution.

12. In paragraph 11, A method for manufacturing a cathode protective layer for a zinc ion battery, characterized in that the heating is performed in a temperature range of 160°C to 200°C.

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