Core-shell structured nanoparticles, method for producing same, and negative electrode material to which particles are applied

Abstract

The present invention relates to a negative electrode for an aqueous battery, the negative electrode comprising, as an active material, a powder aggregate having a 3D nanoparticle form, wherein the powder comprises: a core part comprising zinc; and a shell part formed on the core part and comprising silver.

Description

Core-shell structured nanoparticles and their manufacturing method, and a cathode material to which these particles are applied

[0001] The present invention relates to a negative electrode for a water-based battery and a water-based battery.

[0002]

[0003] Lithium-ion batteries are widely used in portable electronic devices such as smartphones, tablets, and laptops, as well as in electric vehicles and energy storage systems (ESS). This widespread use is due to the high energy density and long lifespan of lithium-ion batteries. Their high energy density allows them to store a large amount of power in a small size, and their long lifespan enables users to use products for an extended period without the inconvenience of frequent replacements.

[0004] However, lithium-ion batteries have several significant drawbacks. First, lithium is a relatively rare resource mined in large quantities in specific regions, such as China. For this reason, the price of lithium remains high, posing a problem regarding the unit cost of the batteries. Second, there are safety issues with lithium-ion batteries. As reported by recent accidents, problems with the internal structure or components of the battery can cause fires, which can lead to major disasters.

[0005] Due to these issues, new alternatives to lithium-ion batteries have been researched, and recently, aqueous batteries have been attracting attention. Among these, research on aqueous zinc batteries has emerged; zinc is more abundant than lithium, resulting in relatively lower costs, and due to the unique properties of zinc metal, it offers higher safety than lithium-ion batteries, drawing significant interest.

[0006] In research on zinc-ion batteries, zinc used as the anode was generally used in the form of thin metal plates or foils. However, when zinc metal plates or foils were used as anode materials in this way, there was a problem of low energy density due to the low utilization efficiency of zinc within the anode. In addition, there was a problem where the battery performance deteriorated due to the formation of dendrites caused by the non-uniform deposition of zinc ions during charging and discharging, which resulted in damage to the zinc foil.

[0007]

[0008] The present invention aims to provide a method for manufacturing a negative electrode for a water-based battery that includes a negative electrode active material, which was previously included in a foil form, in a powder form. Furthermore, the powder has zinc as its main component, which has high stability even in powder form.

[0009] In addition, the present invention aims to provide a negative electrode for an aqueous battery manufactured by the above method and an aqueous battery including the same.

[0010] However, the purpose of the present invention is to realize all technical advantages achievable through the contents proposed in the following disclosure, and is not limited to the contents described above.

[0011]

[0012] In a negative electrode for a water-based battery according to one embodiment of the present invention, the negative electrode comprises an aggregate of powder having a 3D nano-particle shape as an active material, and the powder comprises: a core portion comprising zinc; and a shell portion comprising silver formed on the core portion.

[0013] According to one embodiment, the cathode may not include a metal foil.

[0014] According to one embodiment, the core portion may be formed by aggregating a plurality of zinc nanoparticles, and the shell portion may be formed by aggregating a plurality of silver nanoparticles.

[0015] According to one embodiment, the powder may have a diameter of each particle within the range of 1 μm to 5 μm.

[0016] According to one embodiment, the powder may have two peaks observed in the binding energy range of 360 eV to 380 eV and the binding energy range of 1050 eV to 1020 eV, respectively, of the XPS graph.

[0017]

[0018] A method for manufacturing a negative electrode for an aqueous battery according to another embodiment of the present invention may include: a zinc nanoparticle preparation step of etching zinc nanoparticles by introducing them into a solvent; a silver solution preparation step of obtaining a solution in which silver ions are dispersed from a silver salt; and a silver-zinc core-shell nanoparticle formation step of coating silver on the surface of the nanoparticles by introducing the prepared zinc nanoparticles into the solution.

[0019] According to one embodiment, the method may further include a post-processing step of washing and drying the silver-zinc core-shell nanoparticles.

[0020] According to one embodiment, the zinc nanoparticle preparation step may include: a first etching step of introducing the zinc nanoparticles into an organic solvent and etching the surface of the zinc nanoparticles; a second etching step of introducing the zinc nanoparticles into an acidic solvent and etching the surface of the zinc nanoparticles; and a step of obtaining the second etched zinc nanoparticles and dispersing them in deionized water (DI water).

[0021] According to one embodiment, the step of preparing the silver solution comprises adding a dispersion stabilizer to the silver solution, and the dispersion stabilizer may include one or more selected from the group consisting of trisodium citrate dihydrate, polyacrylic acid, and cetyltrimethylammonium bromide.

[0022] According to one embodiment, the concentration of the dispersion stabilizer solution may be 1 mM to 5 mM, and the mixing volume ratio of the silver solution to the dispersion stabilizer solution may be 10:1 to 3:1.

[0023] According to one embodiment, the step of forming silver-zinc core-shell nanoparticles may involve adding a solution in which zinc nanoparticles are dispersed in deionized water to the silver solution, and synthesizing silver-zinc powder by bonding silver to the surface of zinc nanoparticles through an oxidation-reduction process.

[0024]

[0025] A water-based battery according to another aspect of the present invention comprises: a positive electrode; a negative electrode spaced apart from the positive electrode; and a water-based electrolyte between the positive electrode and the negative electrode, wherein the negative electrode may be a negative electrode for a water-based battery comprising the metal powder of the above-described embodiment as an active material.

[0026]

[0027] The negative electrode for an aqueous battery proposed in the present invention utilizes a powder form rather than the conventionally used foil form, thereby enabling the realization of high energy density by controlling the N / P ratio. Additionally, by bonding silver to the surface of zinc nanoparticles, corrosion of the zinc nanoparticles and hydrogen generation can be suppressed.

[0028] However, the effects of the present invention are not limited to those described above, but include all effects naturally realized through the various configurations proposed in the present invention.

[0029]

[0030] FIG. 1 is a schematic diagram of the process in which silver and zinc meet and are reduced and oxidized, respectively, to form a core-shell structure, as proposed in one embodiment of the present invention.

[0031] Figure 2 is a graph comparing the energy densities of a battery made with a negative electrode containing a metal foil and a metal powder.

[0032] Figure 3 is an XRD graph of silver-zinc core-shell nanoparticles of one embodiment of the present invention.

[0033] Figure 4 is an XPS graph of untreated zinc nanoparticles and silver-zinc core-shell nanoparticles of one embodiment of the present invention.

[0034] Figure 5 is a schematic diagram illustrating the oxidation of zinc and the reduction of silver depending on the use of a dispersion stabilizer.

[0035] Figure 6 is an SEM image of untreated zinc nanoparticles, silver-zinc core-shell nanoparticles without a dispersion stabilizer, and silver-zinc core-shell nanoparticles with a dispersion stabilizer.

[0036] Figure 7 is a graph of the electrochemical stability when silver-zinc core-shell nanoparticles of one embodiment of the present invention are applied to the negative electrode active material of a zinc ion battery.

[0037] FIG. 8 is a graph comparing the degree of hydrogen generation and corrosion of each cathode material when untreated zinc nanoparticles and silver-zinc core-shell nanoparticles according to one embodiment of the present invention are each prepared as active materials.

[0038]

[0039] The embodiments of the present invention are illustrative for the purpose of explaining the technical concept of the present invention. The scope of rights according to the present invention is not limited to the embodiments presented below or the specific description thereof.

[0040] All technical and scientific terms used in this invention, unless otherwise defined, have the meaning generally understood by those skilled in the art to which this invention pertains. All terms used in this invention are selected for the purpose of further explaining this invention and are not selected to limit the scope of rights according to this invention.

[0041] Expressions such as "comprising," "having," "having," etc. used in the present invention should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence containing such expressions.

[0042] Unless otherwise stated, singular expressions described in the present invention may include the meaning of the plural form, and this applies likewise to singular expressions described in the claims.

[0043]

[0044] In a negative electrode for an aqueous battery comprising a metal powder as an active material according to one embodiment of the present invention, the negative electrode comprises an aggregate of powder having a 3D nanoparticle shape as an active material, and the powder may comprise: a core portion comprising zinc; and a shell portion comprising silver formed on the core portion. The 3D nanoparticle is a nanoparticle having a core-shell structure.

[0045] The above 3D nanoparticles are formed into a core-shell structure through reduction and oxidation processes when silver and zinc meet, as explained in detail with Figure 1.

[0046]

[0047] FIG. 1 is a schematic diagram of the process of forming core-shell nanoparticles through an oxidation-reduction process proposed in one embodiment of the present invention. Zinc nanoparticles react with a solution in which silver cations are dispersed. In this process, the zinc nanoparticles are oxidized to Zn 2+ It emits ions and electrons (2e), and silver cations (Ag) present in the solution receive electrons and are reduced to Ag metal. In this way, the silver metal reduced can be deposited on the zinc surface to form the silver-zinc core-shell powder proposed in the embodiment of the present invention. However, this method is merely one example for manufacturing the silver-zinc core-shell powder proposed in the present invention, and the silver-zinc core-shell powder can be manufactured by various other methods.

[0048] According to one embodiment, the core may be formed by aggregating a plurality of zinc nanoparticles, and the shell may be formed by aggregating a plurality of silver nanoparticles.

[0049] According to one embodiment, the powder may have a diameter of 1 μm to 5 μm for each particle. The powder proposed in the present invention may have a diameter on the scale of several μm.

[0050] According to one embodiment, the cathode may not include a metal foil. In the case of conventional use of metal foil, the metal actually participating in the reaction was located on the surface of the foil and was limited to only a portion capable of contacting the electrolyte. Due to the structure of the foil, it was generally the case that the proportion of zinc not participating in the reaction was much higher than that of zinc participating in the reaction. However, the cathode for an aqueous battery according to one embodiment of the present invention is manufactured using zinc powder, thereby reacting a much larger amount of metal than when using foil, resulting in a higher energy density. Furthermore, by using zinc among the metals, it is possible to maintain a stable cathode form even in powder form.

[0051]

[0052] For example, experimental results by the inventors show that under identical conditions, a battery using a negative electrode material containing a zinc metal foil contains approximately 40 mg of active material when the diameter of the zinc metal foil is 1.2 cm and the thickness is 50 μm. On the other hand, when the diameter is the same at 1.2 cm but the thickness is 250 μm, it contains approximately 205 mg of active material. Here, the active material refers to zinc that actually participates in the electrochemical reaction. The thicker the foil, the more active material must be contained. Making the foil thinner is costly, and thin foils have the problem of being prone to deformation. As the thickness of the zinc metal foil increases, the utilization rate of zinc during charging and discharging decreases. Consequently, the negative electrode material containing the zinc metal foil has a relatively low energy density. Furthermore, surface defects of the zinc foil, such as scratches, cracks, and folds that occur during commercial manufacturing and testing, prevent the zinc from being deposited evenly and cause side reactions.

[0053] On the other hand, a battery using a negative electrode material containing zinc powder can flexibly adjust the amount of active material to 10 mg or less, which increases the zinc utilization rate and thus improves space utilization at the cell level, allowing for high energy density.

[0054]

[0055] FIG. 2 is a table image comparing the energy densities achieved in each case when a battery is fabricated by configuring a negative electrode containing a metal foil corresponding to a comparative example of the present invention and a metal powder corresponding to an embodiment of the present invention. FIG. 2 presents a comparison of electrical characteristics according to the combination of each negative electrode and a positive electrode. Through the experimental values ​​presented in FIG. 2, the energy densities according to the combinations of materials of the zinc metal foil and zinc powder used in the negative electrode can be compared.

[0056] The inventors introduced MnO2, VO2, V2O5-PEDOT, PANI, and MnO2 as cathode materials while manufacturing a battery to include a metal foil-based zinc cathode as a comparative example to compare with the embodiments of the present invention.

[0057] In addition, embodiments of the present invention were prepared by manufacturing a battery with the same configuration for the remaining conditions, including the anode, except that the negative electrode material form was powder rather than foil and was manufactured using the material proposed in each case of FIG. 2.

[0058] Through the experimental results of Figure 2, it was confirmed that the powder-based examples exhibited higher energy density and superior electrical characteristics compared to the foil-based comparative example.

[0059]

[0060] Below, the formation of silver-zinc core-shell nanoparticles is confirmed through Figures 3 and 4.

[0061] FIG. 3 is an XRD graph of silver-zinc core-shell nanoparticles of one embodiment of the present invention. In the XRD graph above, diffraction peaks of both silver and zinc are observed, which confirms that the nanoparticles have formed the intended core-shell structure.

[0062]

[0063] Figure 4 is an XPS graph of zinc nanoparticles without surface treatment and silver-zinc core-shell nanoparticles according to one embodiment of the present invention as another comparative example of the present invention. The two graphs at the top of Figure 4 show the XPS spectra of zinc nanoparticles without surface treatment. In the top left XPS graph, the Ag 3D peak does not appear, whereas in the top right XPS graph, Zn 2P 3 / 2 and Zn 2P 1 / 2It can be observed that peaks appear at 1020 eV and 1045 eV. Through this, it can be understood that the zinc nanoparticles without surface treatment consist only of zinc and do not contain silver.

[0064] The two graphs at the bottom of Fig. 4 show the XPS spectra of silver-zinc core-shell nanoparticles. In the XPS graph on the bottom left, Ag 3d 5 / 2 and Ag 3d 3 / 2 Peaks appear near 368 eV and 374 eV, respectively, and also, in the bottom right XPS graph, Zn 2P 3 / 2 and Zn 2P 1 / 2 It is confirmed that a peak also appears. Through this, it can be confirmed that a silver coating is formed on the silver-zinc core-shell nanoparticles, and that the nanoparticles are composed of zinc and silver.

[0065] According to the above example, two peaks can be observed in the co-shell nanoparticle powder in the binding energy range of 360 eV to 380 eV and the binding energy range of 1050 eV to 1020 eV, respectively, of the XPS graph.

[0066]

[0067] Next, a method for manufacturing a negative electrode for an aqueous battery comprising metal powder as an active material is described in detail. However, it should be understood that these manufacturing examples represent some experimental methods and configurations to illustratively explain the present invention, and that the scope of the present invention is not limited to these examples.

[0068]

[0069] A method for manufacturing a negative electrode for an aqueous battery according to another embodiment of the present invention may include: a step of preparing zinc nanoparticles; a step of preparing a silver solution in which silver ions are dispersed from a silver salt; and a step of forming silver-zinc core-shell nanoparticles in which the prepared zinc nanoparticles are introduced into the solution to coat silver on the surface of the nanoparticles.

[0070] According to one embodiment, a post-processing step of washing and drying the silver-zinc core-shell nanoparticles during or after the above steps may be further included.

[0071] According to one embodiment, the zinc nanoparticle preparation step involves pretreatment of the zinc nanoparticles. The step may include: a first etching step in which the zinc nanoparticles are introduced into an organic solvent and the surface of the zinc nanoparticles is etched; a second etching step in which the zinc nanoparticles are introduced into an acidic solvent and the surface of the zinc nanoparticles is etched; and a step of obtaining the second etched zinc nanoparticles and dispersing them in deionized water (DI water).

[0072] The above organic solvent may include one or more selected from the group consisting of ethanol and acetone. The above acid solvent may include one or more selected from the group consisting of HCl and acetic acid.

[0073] As one example of the zinc nanoparticle preparation step above, 0.7 g of zinc nanoparticles can be placed in 20 mL of acetone and subjected to a first etching using a sonicator. After obtaining the zinc nanoparticles subjected to the first etching through filtering, they can be placed in 20 mL of a 0.05 M HCl solution and subjected to a second etching using a sonicator. The zinc nanoparticles subjected to the second etching can be placed in 10 mL of deionized water and dispersed.

[0074] According to one embodiment, the step of preparing the silver solution comprises adding a dispersion stabilizer to the silver solution, and the dispersion stabilizer may include one or more selected from the group consisting of trisodium citrate dihydrate solution, polyacrylic acid, and hexadecyltrimethylammonium bromide. The dispersion stabilizer may serve to prevent the aggregation of nanoparticles.

[0075] The prevention of nanoparticle aggregation by the above dispersion stabilizer is explained in detail together with Figures 5 and 6.

[0076]

[0077] First, (a) of Fig. 5 is a schematic diagram of the oxidation-reduction process when no dispersion stabilizer is used, and (b) is a schematic diagram of the oxidation-reduction process when a dispersion stabilizer is used.

[0078] In case (a), where no dispersion stabilizer is used, the silver particles are not evenly dispersed on the surface of the zinc nanoparticles and aggregate. However, in case (b), where the dispersion stabilizer used in one embodiment of the present invention is used, it can be confirmed that the silver particles are evenly dispersed on the surface of the zinc nanoparticles.

[0079]

[0080] Figure 6 is an SEM image of untreated zinc powder, silver-zinc core-shell nanoparticles without a dispersion stabilizer, and silver-zinc core-shell nanoparticles with a dispersion stabilizer.

[0081] It can be seen that no silver particles are formed on the surface of the zinc powder (A) that has not undergone surface treatment. In comparison, silver particles are formed on the zinc powder in the silver-zinc core-shell nanoparticles (B) that do not use a dispersion stabilizer and the silver-zinc core-shell nanoparticles (C) that use a dispersion stabilizer.

[0082] On the surface of silver-zinc core-shell nanoparticles (B) without a dispersion stabilizer, it can be observed that the silver particles are aggregated. On the other hand, on the surface of silver-zinc core-shell nanoparticles (C) with a dispersion stabilizer, it can be observed that the silver particles are uniformly dispersed. If the surface is evenly dispersed, the reaction can occur evenly across the entire electrode surface, allowing for uniform energy transfer during the charging and discharging process of the battery and preventing localized overheating. Through this, the performance of the dispersion stabilizer used in one embodiment of the present invention can be confirmed.

[0083] In the following example, a dispersion stabilizer solution of trisodium citrate dihydrate was used, and the experimental method was improved by optimizing the concentration, ratio, and stirring time of the solution through the dispersion stabilizer.

[0084] According to one embodiment, the concentration of the dispersion stabilizer solution may be 1 mM to 5 mM, and the mixing volume ratio of the silver solution to the dispersion stabilizer solution may be 10:1 to 3:1.

[0085] As an example of the silver solution preparation step above, 50 mL of 0.5 mM silver nitrate solution (AgNO3) can be prepared and stirred at 200 rpm for 20 minutes. Then, 10 mL of 3 mM trisodium citrate dihydrate solution can be stirred at 200 rpm for 20 minutes.

[0086] A solution of trisodium citrate dihydrate, which has undergone a stirring step, is slowly added drop by drop to a silver nitrate solution that has undergone a stirring step. The solution mixed above can be stirred at 400 rpm for 20 minutes.

[0087] According to one embodiment, the step of forming silver-zinc core-shell nanoparticles may involve adding a solution in which zinc nanoparticles are dispersed in deionized water to the silver solution, and synthesizing silver-zinc powder by bonding silver to the surface of zinc nanoparticles through an oxidation-reduction process.

[0088] The silver-zinc core-shell nanoparticle formation step can be performed by pipetting the second etched zinc nanoparticles from the deionized water prepared in the zinc nanoparticle preparation step, adding them to the mixed solution prepared in the silver solution preparation step, and stirring at 400 rpm for 1 hour.

[0089] In the above post-processing step, the silver-zinc powder generated in the silver-zinc core-shell nanoparticle formation step may be washed with ethanol or water and then dried at room temperature or under vacuum.

[0090] The manipulation variables to be considered in the method for manufacturing a negative electrode for an aqueous battery containing the above metal powder as an active material include the molar concentration of the silver nitrate solution, the molar concentration of the trisodium citrate dihydrate solution, and the stirring time.

[0091]

[0092] An aqueous battery comprising a metal powder active material negative electrode according to another aspect of the present invention comprises: a positive electrode; a negative electrode spaced apart from the positive electrode; and an aqueous electrolyte between the positive electrode and the negative electrode, wherein the negative electrode may be a negative electrode for an aqueous battery comprising the metal powder described above as an active material. In addition, the aqueous battery may further comprise a separator.

[0093] The performance of a battery according to another aspect of the present invention will be described below together with FIGS. 7 and FIGS. 8.

[0094] According to one embodiment, the battery may maintain a 75% Coulomb efficiency even after 200 charge-discharge cycles.

[0095]

[0096] Through Fig. 7, the electrochemical stability of silver-zinc core-shell nanoparticles according to one embodiment of the present invention when applied as a negative electrode active material of a zinc battery is confirmed.

[0097] The top graph of Fig. 7 is a graph showing the change in voltage over time. In the top graph, it can be seen that when silver-zinc core-shell nanoparticles (blue graph) are applied to the cathode active material, the graph is measured in a constant shape without fluctuations in the voltage curve during the measurement time.

[0098] On the other hand, when surface-untreated zinc nanoparticles (gray graph) are applied to the cathode active material, it can be observed that the graph of the surface-untreated zinc nanoparticles shows a large range of voltage fluctuations and is measured only up to the beginning of the measurement time.

[0099] The discharge capacity and Coulomb efficiency can be seen in the bottom graph of Figure 7. In the case of silver-zinc core-shell nanoparticles (blue graph), the initial discharge capacity starts at about 250 mAh / g, and it can be seen that the capacity is maintained at a level similar to the initial discharge capacity even after about 200 cycles.

[0100] On the other hand, it can be seen that the initial discharge capacity of zinc nanoparticles without surface treatment started at about 200 mAh / g and dropped to 150 mAh / g after about 200 cycles.

[0101] In addition, it was confirmed that the Coulomb efficiency of silver-zinc core-shell nanoparticles is 75%, whereas the Coulomb efficiency of zinc nanoparticles without surface treatment is only 50%. Through this, it can be seen that applying silver-zinc core-shell nanoparticles according to one embodiment of the present invention as a negative electrode active material maintains high discharge capacity and Coulomb efficiency even after several charge-discharge cycles. This means that the battery according to one embodiment of the present invention has a long lifespan, is stable, and has excellent electrochemical performance.

[0102] According to one embodiment, the battery can suppress hydrogen generation more effectively than an aqueous battery containing a negative electrode formed of pure zinc powder.

[0103]

[0104] Figure 8 is a graph measuring the hydrogen generation and corrosiveness of untreated zinc nanoparticles and silver-zinc core-shell nanoparticles.

[0105] The rate of the hydrogen generation reaction can be confirmed through the graph on the left in Fig. 8. The blue graph and the gray graph represent the graphs of silver-zinc core-shell nanoparticles and core-shell nanoparticles without surface treatment, respectively.

[0106] The lowest current density point of the graph of silver-zinc core-shell nanoparticles was measured to be lower than the lowest current density point of the graph of core-shell nanoparticles without surface treatment. This means that applying silver-zinc core-shell nanoparticles according to one embodiment of the present invention to a battery results in less hydrogen generation and can suppress corrosion or hydrogen generation.

[0107] According to one embodiment, the battery may exhibit better corrosion test results than an aqueous battery comprising a negative electrode formed of pure zinc powder.

[0108] The corrosion potential and corrosion current density are observed in the graph on the right side of Figure 8. The blue and gray graphs are graphs of silver-zinc core-shell nanoparticles and zinc nanoparticles without surface treatment, respectively.

[0109] It can be confirmed that at the same current density, the potential of the silver-zinc core-shell nanoparticle electrode is lower than that of zinc nanoparticles without surface treatment. This means that it has higher resistance to corrosion because a lower potential is required for the corrosion reaction to occur.

[0110] Through the two graphs of Fig. 8, it can be seen that the negative electrode material containing silver-zinc core-shell nanoparticles as an active material according to one embodiment of the present invention exhibits less hydrogen generation reaction and has higher resistance to corrosion, making it more electrochemically stable.

[0111]

[0112] The present invention presents a coating technology for manufacturing a silver-zinc core-shell structure in nano-particle size and proposes a method for uniform reduction and stabilization of silver nanoparticles using a dispersion stabilizer. The nano-composite material produced by the above invention can be used as a negative electrode material for a zinc battery to improve the performance and lifespan of the battery.

[0113]

[0114] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. In the negative electrode of an aqueous battery, The above cathode comprises an aggregate of powder having a 3D nanoparticle shape as an active material, and The above powder is, A core part containing zinc; and A shell portion comprising silver formed on the core portion; comprising A negative electrode for an aqueous battery containing metal powder as an active material.

2. In Paragraph 1, The above cathode does not include a metal foil, A negative electrode for an aqueous battery containing metal powder as an active material.

3. In Paragraph 1, The above core part is formed by the aggregation of multiple zinc nanoparticles, and The above shell portion is formed by the aggregation of a plurality of silver nanoparticles, A negative electrode for an aqueous battery containing metal powder as an active material.

4. In Paragraph 1, The above powder is one in which the diameter of each particle is 1 μm to 5 μm, A negative electrode for an aqueous battery containing metal powder as an active material.

5. In Paragraph 1, The above powder is one in which two peaks are observed in the binding energy range of 360 eV to 380 eV and the binding energy range of 1050 eV to 1020 eV, respectively, of the XPS graph. A negative electrode for an aqueous battery containing metal powder as an active material.

6. Zinc nanoparticle preparation step; A step for preparing a silver solution to obtain a solution in which silver ions are dispersed from a silver salt; and A silver-zinc core-shell nanoparticle formation step comprising adding the prepared zinc nanoparticles to the solution to coat silver on the surface of the nanoparticles; Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

7. In Paragraph 6, A post-processing step of washing and drying the above silver-zinc core-shell nanoparticles; further comprising Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

8. In Paragraph 6, The above zinc nanoparticle preparation step is, A first etching step of introducing the zinc nanoparticles into an organic solvent and etching the surface of the zinc nanoparticles; A second etching step of introducing the zinc nanoparticles into an acid solvent and etching the surface of the zinc nanoparticles; and A step comprising obtaining the above second etched zinc nanoparticles and dispersing them in deionized water (DI water); Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

9. In Paragraph 6, The above step of preparing the silver solution is, It includes adding a dispersion stabilizer to the above silver solution, and The above dispersion stabilizer comprises one or more selected from the group consisting of trisodium citrate dihydrate, polyacrylic acid, and cetyltrimethylammonium bromide. Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

10. In Paragraph 9, The concentration of the above dispersion stabilizer solution is 1 mM to 5 mM, and The mixing volume ratio of the above silver solution to the dispersion stabilizer solution is 10:1 to 3:1, Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

11. In Paragraph 6, The above silver-zinc core-shell nanoparticle formation step is, A method in which a solution in which zinc nanoparticles are dispersed in deionized water is added to the silver solution, and silver is bonded to the surface of the zinc nanoparticles through an oxidation-reduction process to synthesize silver-zinc powder. Method for manufacturing a negative electrode for an aqueous battery containing metal powder as an active material.

12. Anode; A cathode spaced apart from the anode; and A water-based electrolyte between the anode and the cathode; comprising, The above cathode is, A negative electrode for an aqueous battery comprising the metal powder of claim 1 as an active material, Aqueous battery comprising a metal powder active material negative electrode.

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