Method for evaluating, in real time, growth form of metal electrode by electroplating, and method for manufacturing metal electrode by using same

Abstract

The present invention relates to a method for evaluating, in real time, a growth form of a metal electrode by electroplating, comprising the steps of: obtaining r0 on the basis of a Nyquist plot for a Fourier transform electrochemical impedance spectroscopy (FTEIS) analysis result of an electroplating system including a metal electrode grown by electrodeposition of a metal element by reduction of metal ions, and a Nyquist plot for a spherical diffusion Warburg impedance represented by expression 1; obtaining rcalc corresponding to the size of a theoretical radius when a complete hemispherical growth of the metal electrode is assumed; and obtaining a ratio (r0 / rcalc) of r0 and rcalc.

Description

Real-time evaluation method for the growth form of a metal electrode by electroplating and a method for manufacturing a metal electrode using the same

[0001] [Cross-citation with related applications]

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0138101, filed October 16, 2023, the entire contents of which are incorporated herein by reference.

[0003] [Technical Field]

[0004] The present invention relates to a real-time evaluation method of the growth form of a metal electrode by electroplating, and a method for manufacturing a metal electrode using the same.

[0005]

[0006] Applying electrical energy to an electrochemical system can induce various chemical changes within the system. Furthermore, these chemical changes can be observed as electrical signals such as current and voltage. Electrochemical impedance spectroscopy (EIS) utilizes the aforementioned method to analyze and explain complex phenomena in electrochemical systems.

[0007] According to electrochemical impedance spectroscopy, it is possible to analyze complex phenomena in an electrochemical system by sequentially applying input signals (e.g., voltage, etc.) with various frequencies to the electrochemical system and then interpreting the output signals (e.g., current, etc.) generated by each input signal.

[0008] For example, by comprehensively analyzing the first output signal when a first input signal having a first frequency is applied to an electrochemical system, and the second output signal when a second input signal having a second frequency different from the first frequency is applied to the electrochemical system, it is possible to analyze phenomena in an electrochemical system. This is because phenomena in an electrochemical system react differently depending on the frequency of the input signal, and by comprehensively analyzing the reactions in the electrochemical system to various frequencies, it is possible to analyze complex phenomena occurring in the electrochemical system.

[0009] However, when input signals with different frequencies are applied separately, the accuracy of the measurement results is reduced due to changes in the electrochemical system being measured during the time period between the application of one input signal and the application of another. Furthermore, because input signals with multiple frequencies must be applied separately, there is the problem that a relatively long time is required to analyze the electrochemical system.

[0010] To overcome these problems, Fourier transform electrochemical impedance spectroscopy (FTEIS) has been proposed. Fourier transform electrochemical impedance spectroscopy (hereinafter referred to as FTEIS throughout this specification) uses a composite signal with multiple frequencies mixed as an input signal, and thus obtains an output signal with a composite signal with multiple frequencies mixed by such an input signal. By performing a Fourier transform on this composite signal, impedance for each frequency can be obtained in real time, thereby improving accuracy and reducing the time required for analysis compared to conventional electrochemical impedance spectroscopy.

[0011]

[0012] The present invention provides an evaluation method for evaluating the growth form of a metal electrode by electroplating in real time using the aforementioned FTEIS, and a manufacturing method for manufacturing a metal electrode using the same.

[0013]

[0014] In order to solve the above-mentioned problem, a real-time evaluation method of a growth form of a metal electrode by electroplating according to an embodiment of the present invention comprises the steps of obtaining r0 based on a Nyquist plot of a Fourier Transform Electrochemical Impedance Spectroscopy (FTEIS) analysis result of an electroplating system including a metal electrode grown by electrodeposition of a metal element by reduction of a metal ion and a Nyquist plot of a spherical diffusion Warburg impedance expressed by Equation 1 below, and r corresponding to the size of a theoretical radius when assuming a complete hemispherical growth of the metal electrode. calc Step of obtaining, and the above r0 and the above r calc The ratio of (r0 / r calc ) includes a step of obtaining.

[0015] [Formula 1]

[0016]

[0017] (In the above equation 1, R is the gas constant, T is the absolute temperature, n is the number of electrons required for the reduction of the metal ion, F is the Faraday constant, A is the area of ​​the metal electrode, D0 is the diffusion coefficient of the metal ion, j is (-1) 1 / 2 , ω is the angular frequency of the input signal in the FTEIS, α is the electron transfer coefficient, and C0(r0,t) is the concentration of the metal ion over time at the position (r0) of the electrode surface.

[0018] In order to solve the above-mentioned problem, the method for manufacturing a metal electrode by electroplating of the present invention includes a real-time evaluation method of the growth form of the metal electrode by electroplating as described above, and the r0 / r calc If the value of r0 / r is less than or equal to 2, calc It includes a step of adjusting the plating conditions in the electroplating system in real time so that the value exceeds 2.

[0019] In order to solve the above-mentioned problem, the method for manufacturing a metal electrode by electroplating of the present invention includes a real-time evaluation method of the growth form of the metal electrode by electroplating as described above, and the r0 / r calc If the value of r0 / r is greater than 2, calc It includes a step of adjusting the plating conditions in the electroplating system in real time so that the value is 2 or less.

[0020]

[0021] The real-time evaluation method of the growth form of the metal electrode by electroplating of the present invention is the above r0 and the above r calc The ratio of (r0 / r calc ) includes a step of obtaining the ratio (r0 / r) here. calc ) is an indicator that shows the growth form of the metal electrode in real time, and the ratio (r0 / r calc ) exceeds 2 and becomes larger, it can be judged that the metal electrode is growing in a form with a relatively high specific surface area, such as a dendritic shape, and the ratio (r0 / r calc ) becomes smaller than 2, it can be judged that the metal electrode is growing in a form with a relatively low specific surface area, such as a smooth lump, and in particular, the ratio (r0 / r calc ) is closer to 1, it can be judged that the metal electrode is practically growing into a hemispherical shape.

[0022] In addition, in the present invention, the ratio (r0 / r) is obtained by using the real-time evaluation method of the growth form of the metal electrode described above.calc ) By setting the plating conditions so that the value satisfies a predetermined range, it is possible to efficiently manufacture a metal electrode suitable for the desired purpose.

[0023]

[0024] Figure 1 is a diagram for explaining an input signal in which multiple signals in the form of sine waves with different frequencies are superimposed in FTEIS analysis.

[0025] Figure 2a is a drawing for explaining an FTEIS analysis device in an electroplating system.

[0026] Figure 2b is a drawing for explaining the correspondence between the Nyquist plot of the FTEIS analysis result in Figure 2a and the Nyquist plot of the spherical diffusion Warburg impedance expressed by Equation 1.

[0027] Figure 3 is a diagram showing the concentration of metal ions distributed around a metal electrode according to the growth form of the metal electrode grown by electroplating.

[0028] Figure 4 shows r0 and r in embodiments according to the accumulated charge. calc This is a graph showing .

[0029] Figure 5 shows r0 and r in embodiments according to the accumulated charge. calc The ratio of (r0 / r calc ) is a graph showing the

[0030] Figure 6 is a graph illustrating a voltage application method in embodiments.

[0031] Figure 7 is an image of a metal electrode in the examples observed using an electron microscope.

[0032]

[0033] Hereinafter, a method for evaluating the growth form of a metal electrode by electroplating in real time and a method for manufacturing a metal electrode using the same will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention pertains can easily perform the method.

[0034] Real-time evaluation method for the growth form of metal electrodes by electroplating

[0035] Growth of metal electrodes by electroplating

[0036] The subject of evaluation in the present invention is an electroplating system including a metal electrode grown by electroplating.

[0037] Electroplating, as used herein, may refer to a process of plating one metal on another using the principle of electrolysis, and the system in which such electroplating is performed may be referred to as an electroplating system. In this case, the electroplating system may include an electrolyte containing the metal ions and / or salts of the metal ions, and three electrodes impregnated in the electrolyte.

[0038] The above electrodes may be a working electrode, a reference electrode, and a counter electrode. The metal element may be electrodeposited on the working electrode, a voltage is applied between the reference electrode and the working electrode, and a current according to the voltage flows between the counter electrode and the working electrode.

[0039] Meanwhile, on the working electrode, a metal electrode may be formed by electrodeposition of the metal element. The metal electrode may gradually grow as the electroplating is performed (i.e., as more of the metal element is electrodeposited as the electroplating time increases). For example, the metal electrode may be a hemispherical electrode whose radius gradually increases as the electroplating is performed.

[0040] In one embodiment, the electroplating system may further include an aperture layer disposed on the working electrode and defining a circular aperture opening a portion of the working electrode. Here, when the electroplating system further includes the aperture layer, the metal element may be deposited on the portion of the working electrode opened by the aperture. That is, the metal electrode may be grown on the portion of the working electrode opened by the aperture.

[0041] Real-time evaluation method of growth morphology of metal electrodes

[0042] The above metal electrode can be grown into various shapes depending on the electroplating conditions (e.g., electroplating voltage, electroplating temperature, electroplating time, etc.) in the above electroplating.

[0043] For example, the metal electrode may be grown on the working electrode to have a substantially hemispherical shape. Alternatively, as another example, the metal electrode may be grown on the working electrode to have a dendrite shape.

[0044] In the present invention, r0 is obtained based on the Nyquist plot of the FTEIS (Fourier Transform Electrochemical Impedance Spectroscopy) analysis results of the electroplating system and the Nyquist plot of the spherical diffusion Warburg impedance expressed by the following equation 1, and r0 is equivalent to the size of the theoretical radius when assuming complete hemispherical growth of the metal electrode. calc The ratio of (r0 / r calc ) to provide a method for evaluating the growth form of the metal electrode by electroplating in real time.

[0045] [Formula 1]

[0046]

[0047] (In the above equation 1, R is the gas constant, T is the absolute temperature, n is the number of electrons required for the reduction of the metal ion, F is the Faraday constant, A is the area of ​​the metal electrode, D0 is the diffusion coefficient of the metal ion, j is (-1) 1 / 2 , ω is the angular frequency of the input signal in the FTEIS, α is the electron transfer coefficient, and C0(r0,t) is the concentration of the metal ion over time at the position (r0) of the electrode surface.

[0048] The FTEIS analysis result of the electroplating system may be performed in real time on the electroplating system by analyzing an input signal in which multiple signals having different frequencies are superimposed on the electroplating system and each output signal generated according to the input signal using Fourier transform. For example, as illustrated in Fig. 1, an input signal in which multiple signals in the form of sine waves having different frequencies are superimposed may be applied to the electroplating system, and it is possible to separate and analyze multiple signals included in the input signal in real time using Fourier transform. In this case, the FTEIS analysis result of the electroplating system may be expressed in real time as an impedance having a real part and an imaginary part.

[0049] The Nyquist plot for the FTEIS analysis results of the above-described electroplating system may be a graph drawn by setting the real part of the above-described impedance as the horizontal axis and the imaginary part as the vertical axis. The graph may be divided into a region corresponding to a low-frequency band of the impedance and other regions. The region corresponding to the low-frequency band of the impedance may be a material transfer region representing the material transfer characteristics of the electrochemical system, and the other regions may be electron transfer regions representing the electron transfer characteristics of the electrochemical system. For example, the left region in the graph (generally represented as a hemisphere) may be an electron transfer region, and the right region in the graph (generally represented as a straight line or a hemisphere, although this may vary depending on the electrode shape or diffusion situation) may be a material transfer region.

[0050] The spherical diffusion Warburg impedance represented by the above equation 1 may have a real part and an imaginary part. In this case, the spherical diffusion Warburg impedance may also be plotted as a Nyquist plot with the real part set as the horizontal axis and the imaginary part set as the vertical axis.

[0051] Here, r0 can be obtained based on the Nyquist plot of the FTEIS analysis results of the electroplating system and the Nyquist plot of the spherical diffusion Warburg impedance. For example, the variables and / or constants in Equation 1 may be appropriately set so that the Nyquist plot of the spherical diffusion Warburg impedance corresponds to the material transfer region in the Nyquist plot of the FTEIS analysis results, and a method of obtaining r0 from Equation 1 in this case may be used.

[0052] More specifically, as illustrated in Fig. 2a, the FTEIS analysis results of the electroplating system can be obtained using an FTEIS analyzer. The FTEIS analyzer may include a working electrode (WE) and a counter electrode (CE). Here, the working electrode (WE) may be an electrode that receives an input signal that is a superimposition of multiple sine wave signals having different frequencies, as described with reference to Fig. 1, and detects a current signal generated therefrom.

[0053] Meanwhile, as illustrated in Fig. 2b, the FTEIS analysis result obtained using the FTEIS analyzer can be represented as a Nyquist plot (FTEIS in Fig. 2b). In this case, the variables and / or constants in Equation 1 can be appropriately set so that the mass transfer region (Spherical Warburg in Fig. 2b) in the Nyquist plot of the spherical diffusion Warburg impedance represented by Equation 1 (Fitted Result in Fig. 2b) corresponds to the mass transfer region in the Nyquist plot for the FTEIS analysis result, and in this case, r0 can be obtained from Equation 1.

[0054] The above r0 may correspond to the actual radius of the growing metal electrode. For example, the above r0 may be a value corresponding to the size of the material transfer area around the growing metal electrode.

[0055] Meanwhile, referring to FIG. 3, the inventors of the present invention have confirmed that when the radius of the material transfer region, r0, is obtained by fitting using the impedance formula and its Nyquist plot for a hemispherical growth shape regardless of the actual growth shape of the metal electrode, the material transfer region described above can be seen as effectively representing the size of the effective radius of the growing metal electrode.

[0056] Here, when the metal electrode grows in a dendrite shape, the size of the material transfer area around the metal electrode may be larger than the size of the material transfer area around the metal electrode when the metal electrode grows in a perfect hemispherical shape. This is because, assuming that they are formed from the same amount of metal elements, a metal electrode that grows in a dendrite shape is distributed over a substantially wider area than a metal electrode that grows in a hemispherical shape.

[0057] Meanwhile, based on the electroplating conditions in the electroplating system, the size of the theoretical radius r corresponding to the case where the complete hemispherical growth of the metal electrode is assumed calc can be obtained. For example, the above r calc can be calculated using the following equation 2.

[0058] [Formula 2]

[0059]

[0060] (In the above equation 2, Q is the charge, M w is the molar mass of the metal element, n is the number of electrons required for the reduction of the metal ion, F is the Faraday constant, and d is the density of the metal composed of the metal element.)

[0061] In the above equation 2, when the charge in electroplating is Q, the number of moles of plated metal is expressed as Q / nF, and the mass of the plated metal here is QM w / nF, the volume of the plated metal is QM w / nFd; and the radius when the metal electrode grows into a perfect hemisphere is r calc When set to , the volume of the hemispherical metal electrode is 2πr calc 3 Based on the representation as / 3, QM w / nFd = 2πr calc 3 / 3 from r calc It may have been produced.

[0062] Here, the ratio (r0 / r calc ) may be an indicator of whether the growth of the metal electrode is close to a growth shape that minimizes the specific surface area, such as a perfect hemisphere, or close to a growth shape that maximizes the specific surface area, such as a dendritic shape, and the degree of closeness. More specifically, the ratio (r0 / r calc ) exceeds 2 and becomes larger, it can be judged that the metal electrode is growing in a form with a relatively high specific surface area, such as a dendritic shape, and the ratio (r0 / r calc ) becomes smaller than 2, it can be judged that the metal electrode is growing in a form with a relatively low specific surface area, such as a smooth lump. In addition, the ratio (r0 / r calc ) is close to 1 (i.e., if the above r0 is close to the above r calc If similar to ), the growth form of the metal electrode can be evaluated as hemispherical growth, and the ratio (r0 / r calc ) becomes larger compared to 1 (i.e., the above r0 is greater than the above r calc If the difference is large), the growth form of the metal electrode can be evaluated as having further transitioned from hemispherical growth to dendritic growth.

[0063] Additionally, as mentioned above, the r0 can be measured in real time, and the r calc It can be calculated in real time by the set plating conditions and properties of the metal elements. That is, the ratio (r0 / r) which is an index for evaluating the growth form of the metal electrode calc ) can be measured in real time while the metal electrode is growing by electroplating.

[0064] In one embodiment, the inventors of the present invention have found that the ratio (r0 / r calc) is 2 or less, it was confirmed that the growth of the metal electrode can be evaluated as growth in the form of a relatively low specific surface area (e.g., hemispherical growth).

[0065] In addition, in one embodiment, the inventors of the present invention have found that the ratio (r0 / r calc ) exceeds 2, it was confirmed that the growth of the metal electrode can be evaluated as growth in the form of a relatively high specific surface area (e.g., dendritic growth).

[0066] Method for manufacturing metal electrodes

[0067] The present invention provides a method for manufacturing a metal electrode, which allows the metal electrode to grow into a predetermined desirable growth shape based on the growth shape of the metal electrode evaluated from the real-time evaluation method of the growth shape of the metal electrode by electroplating described above.

[0068] In one embodiment, if the above-described preferred growth form is dendritic growth, the method for manufacturing the metal electrode is calc ) is less than or equal to 2, the above ratio (r0 / r calc ) may include a step of adjusting the plating conditions in real time in the electroplating system so that the value of the ratio (r0 / r) exceeds 2. Here, the step of adjusting the plating conditions in real time may include, for example, a step of lowering the electroplating voltage in the electroplating system in real time, but the present invention is not limited thereto. That is, the step of adjusting the plating conditions in real time may include the step of lowering the electroplating voltage in real time in the electroplating system, but the present invention is not limited thereto. calc ) may include a step of adjusting various plating conditions (e.g., plating temperature, etc.) that can change the value of ) to exceed 2.

[0069] In one embodiment, if the above-described preferred growth form is a hemispherical growth, the method for manufacturing the metal electrode is calc ) is greater than 2, the ratio (r0 / r calc) may include a step of adjusting the plating conditions in real time in the electroplating system so that the value of the ratio (r0 / r) is 2 or less. Here, the step of adjusting the plating conditions in real time may include, for example, a step of increasing the electroplating voltage in the electroplating system in real time, but the present invention is not limited thereto. That is, the step of adjusting the plating conditions in real time may include the step of increasing the electroplating voltage in real time in the electroplating system, but the present invention is not limited thereto. calc ) may include a step of adjusting various plating conditions (e.g., plating temperature, etc.) so that the value of ) can be changed to 2 or less.

[0070] As described above, when the predetermined preferred growth form is dendritic growth, the electroplating system may be an electroplating system for forming a sensor electrode. The sensor electrode needs to have a maximum specific surface area to increase its sensitivity. Therefore, the sensor electrode preferably has a dendritic shape having a relatively large specific surface area. Meanwhile, when the electroplating system is an electroplating system for forming a sensor electrode, the metal electrode may be the sensor electrode.

[0071] In addition, in the above-mentioned case where the predetermined preferable growth form is hemispherical growth, the electroplating system may be an electroplating system for forming a metal anode of a lithium secondary battery. Here, the metal anode in the lithium secondary battery is disposed to face the positive electrode of the lithium secondary battery, and a separator and / or an electrolyte may be disposed between the metal anode and the positive electrode of the lithium secondary battery. In this case, when the metal anode has a dendritic shape, a problem may occur in which the metal anode penetrates the separator and / or the electrolyte to make electrical contact with the positive electrode of the lithium secondary battery. Therefore, in order to prevent this problem, it is preferable that the dendritic growth of the metal anode of the lithium secondary battery is suppressed. Meanwhile, when the electroplating system is an electroplating system for forming a metal anode of the lithium secondary battery, the metal electrode may be a metal anode of the lithium secondary battery.

[0072]

[0073] Hereinafter, the present invention will be described in more detail through examples. However, these examples are provided solely to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0074]

[0075] Example 1: Real-time evaluation of the growth morphology of metal electrodes by electroplating.

[0076] Based on the Nyquist plot of the FTEIS analysis results of the electroplating system obtained using the FTEIS analyzer (see Fig. 2a) and the Nyquist plot of the spherical diffusion Warburg impedance expressed by the above equation 1, r0 was measured in real time during the electroplating process to obtain a graph of the accumulated charge dependence of r0, and r corresponding to the size of the theoretical radius assuming a complete hemispherical growth of the metal electrode in the electroplating system calc r is calculated in real time calcThe cumulative charge dependence graph was obtained, and the results are shown in Fig. 4. In addition, r0 and r measured and calculated in real time while electroplating was in progress calc The ratio of (r0 / r calc ) and find the ratio (r0 / r calc ) was obtained and the results are shown in Fig. 5.

[0077] The electroplating system herein includes an electrolyte and a working electrode, a reference electrode, and a counter electrode impregnated therein, and an FTEIS analyzer is electrically connected to the working electrode, the reference electrode, and the counter electrode, respectively, to apply an input signal in which a plurality of signals having different frequencies are superimposed to the electroplating system, and an output signal generated by the input signal is measured.

[0078] Here, as shown in Fig. 6, the electroplating voltage (E) for 10 seconds dep ) for 40 seconds after the input signal (E FT ) was repeatedly performed, and the input signal (E FT ) was selected as a signal with a voltage and frequency that did not substantially affect electroplating. More specific experimental information is given in Table 1 below.

[0079]

[0080] Working electrode: 99.99% platinum; and an aperture layer (AZ4620) disposed on the electrode layer and defining a circular aperture (diameter: 1 mm) that opens a portion of the electrode layer. Counter electrode: 99.99% platinum. Electrolyte: AuCl4. - 10 mM aqueous solution electroplating voltage (E dep )-0.14V (relative to the reference electrode) input signal (E FT ) Multiple signals selected from the frequency range of 0.5 Hz to 10 kHz

[0081]

[0082] Examples 2 to 5: Real-time evaluation of the growth morphology of metal electrodes by electroplating

[0083] Electroplating voltage (E dep ) was set as described in Table 2 below, and the graph of the cumulative charge dependence of r0, r, was performed in the same manner as in Example 1. calc Accumulated charge dependence graph of , and r0 and r calc The ratio of (r0 / r calc ) were obtained, and the results are shown in Figs. 4 and 5.

[0084]

[0085] Electroplating voltage (E dep ) Example 20.06 V Example 30.26 V Example 40.46 V Example 50.66 V

[0086]

[0087] Referring to FIG. 4, in Examples 1 to 5, the increase in r0 according to the accumulated charge is determined by the electroplating voltage (E dep ) was the largest in the case of the lowest example 1, and the electroplating voltage (E dep ) was confirmed to be the smallest in the case of the highest example 5.

[0088] Referring to Figure 5, r0 and r according to the accumulated charge calc The ratio of (r0 / r calc ) is the electroplating voltage (E dep ) was confirmed to have a value exceeding 2 in general for the lowest example 1, and overall, r0 and r according to the accumulated charge calc The ratio of (r0 / r calc ) is the electroplating voltage (E dep ) can be seen to decrease as it gets higher.

[0089] Meanwhile, from the data in Fig. 5, r0 and r in the section where the accumulated charge is 0.5 mC or more calc The ratio of (r0 / r calc) It was predicted that the metal electrode of Example 1, which generally exceeds 2, would grow closer to the dendritic phase with a relatively high specific surface area, and r0 and r in the section of accumulated charge of 0.5 mC or more calc The ratio of (r0 / r calc ) It was predicted that the metal electrodes of Examples 2 to 5, which are generally less than 2, grow closer to a hemisphere with a relatively low specific surface area, where r0 and r in the section of accumulated charge of 0.5 mC or more calc The ratio of (r0 / r calc ) It was predicted that the metal electrode of Example 5, which is closest to 1, would grow closest to a hemisphere. In addition, to confirm this prediction, the experiment of Experimental Example 1 below was conducted.

[0090] Here, r0 and r in the section of accumulated charge of 0.5 mC or more calc The ratio of (r0 / r calc ) to judge the growth form of the metal electrode, the section where the accumulated charge is less than 0.5 mC can be seen as the initial growth stage of the metal electrode, in which case r, which represents the size of the theoretical radius, calc Since r0 and r are produced very small calc The ratio of (r0 / r calc ) is measured relatively large, and for this reason, the reliability of judging the growth form of the metal electrode is not sufficiently guaranteed.

[0091]

[0092] Experimental Example 1: Electron Microscope Image Analysis of Metal Electrodes

[0093] For the metal electrodes of Examples 1 to 5, electron microscope images of the metal electrodes at an accumulated charge of 2.0 mC were taken, and the results are shown in Fig. 7.

[0094] Referring to Fig. 7, the metal electrode (E) of Example 1 dep: -0.14 V) it can be confirmed that it grew into a dendritic electrode, and in contrast, the metal electrode of Example 2 (E dep : 0.06 V), the metal electrode of Example 3 (E dep : 0.26 V), the metal electrode of Example 4 (E dep : 0.46 V), and the metal electrode of Example 5 (E dep : 0.66 V) were confirmed to have grown into hemispherical electrodes. In particular, in Fig. 7, r0 and r calc The ratio of (r0 / r calc ) is the metal electrode (E) of Example 5, which is generally closest to 1 dep : 0.66V) was confirmed to have grown closest to a hemisphere.

Claims

1. A step of obtaining r0 based on a Nyquist plot of the results of Fourier Transform Electrochemical Impedance Spectroscopy (FTEIS) analysis of an electroplating system including a metal electrode grown by electrodeposition of a metal element by reduction of a metal ion and a Nyquist plot of a spherical diffusion Warburg impedance represented by Equation 1 below; r, which corresponds to the theoretical radius size assuming complete hemispherical growth of the above metal electrode. calc Steps to obtain; and The above r0 and the above r calc The ratio of (r0 / r calc ) A real-time evaluation method for the growth form of a metal electrode by electroplating, comprising a step of obtaining a morphology. [Formula 1] (In the above equation 1, R is the gas constant, T is the absolute temperature, n is the number of electrons required for the reduction of the metal ion, F is the Faraday constant, A is the area of ​​the metal electrode, D0 is the diffusion coefficient of the metal ion, j is (-1) 1 / 2 , ω is the angular frequency of the input signal in the FTEIS, α is the electron transfer coefficient, and C0(r0,t) is the concentration of the metal ion according to position (r0) and time.

2. In claim 1, A real-time evaluation method for the growth form of a metal electrode by electroplating, wherein the step of obtaining the above r0 includes corresponding the Nyquist plot of the spherical diffusion Warburg impedance to the material transfer region in the Nyquist plot for the FTEIS analysis results.

3. In claim 1, A real-time evaluation method for the growth form of a metal electrode by electroplating, wherein the input signal in the above FTEIS is a superposition of multiple signals having different frequencies.

4. In claim 1, The above r calc A real-time evaluation method for the growth form of a metal electrode by electroplating, calculated by the following equation 2. [Formula 2] (In the above equation 2, Q is the charge, M w is the molar mass of the metal element, n is the number of electrons required for the reduction of the metal ion, F is the Faraday constant, and d is the density of the metal composed of the metal element.) 5. In claim 1, The above r0 / r calc A real-time evaluation method for the growth form of a metal electrode by electroplating, further comprising a step of evaluating the growth form of the metal electrode as hemispherical growth when the value is 2 or less.

6. In claim 1, The above r0 / r calc A real-time evaluation method for the growth form of a metal electrode by electroplating, further comprising a step of evaluating the growth form of the metal electrode as dendritic growth when the value is greater than 2.

7. In claim 1, A real-time evaluation method for the growth morphology of a metal electrode by electroplating, wherein the electroplating system comprises a working electrode and an aperture layer disposed on the working electrode and defining a circular aperture opening a portion of the working electrode.

8. In claim 7, A real-time evaluation method for the growth form of a metal electrode by electroplating, wherein the metal element is deposited on the part of the working electrode opened by the opening, thereby growing the metal electrode.

9. A real-time evaluation method for the growth form of a metal electrode by electroplating according to any one of claims 1 to 8; and The above r0 / r calc If the value of r0 / r is less than or equal to 2, calc A method for manufacturing a metal electrode by electroplating, comprising a step of controlling plating conditions in the electroplating system in real time so that the value of exceeds 2.

10. In claim 9, A method for manufacturing a metal electrode by electroplating, wherein the step of controlling the plating conditions in real time includes the step of lowering the electroplating voltage in the electroplating system in real time.

11. In claim 9, The above electroplating system is an electroplating system for forming electrodes for sensors, and is a method for manufacturing a metal electrode by electroplating.

12. In claim 11, The above metal electrode is a method for manufacturing a metal electrode by electroplating, which is an electrode for a sensor.

13. A real-time evaluation method for the growth form of a metal electrode by electroplating according to any one of claims 1 to 8; and The above r0 / r calc If the value of r0 / r is greater than 2, calc A method for manufacturing a metal electrode by electroplating, comprising a step of adjusting the plating conditions in the electroplating system in real time so that the value of is 2 or less.

14. In claim 13, A method for manufacturing a metal electrode by electroplating, wherein the step of controlling the plating conditions in real time includes the step of increasing the electroplating voltage in the electroplating system in real time.

15. In claim 13, The above electroplating system is an electroplating system for forming a metal negative electrode of a lithium secondary battery, and is a method for manufacturing a metal electrode by electroplating.

16. In claim 15, The above metal electrode is a metal negative electrode of the lithium secondary battery, and is a method for manufacturing a metal electrode by electroplating.

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