JP7715851B2 - Power supply device, control method thereof, and power supply system - Google Patents

Description

The present invention relates to a power supply device, a control method thereof, and a power supply system, and in particular to a power supply device with increased specific capacity, a control method thereof, and a power supply system.

An aluminum electrolytic capacitor contains at least a positive electrode, a negative electrode, and an electrolyte. Electrode foil is the material used to manufacture the positive and negative electrodes of an aluminum electrolytic capacitor and is primarily used to store electrical charge. Electrode foil is made primarily from high-purity aluminum foil and is formed through a series of processing steps, including corrosion and chemical conversion. The manufacturing process for an aluminum electrolytic capacitor is explained in more detail below: Anode aluminum foil, which has been corroded and covered with a dielectric layer (i.e., an oxide film), cathode aluminum foil, and electrolytic paper are wound together, then immersed in electrolyte and sealed in an aluminum case.

The quality of the electrode foil has a decisive impact on the overall performance of an aluminum electrolytic capacitor, and the electrode foil's corrosion and formation processes directly determine the aluminum electrolytic capacitor's performance, including capacitance, leakage current, loss, lifespan, reliability, and volume. For example, the higher the specific capacitance of the electrode foil, the higher the unit charge of the electrode foil, and the smaller the volume of the aluminum electrolytic capacitor that can be manufactured at the same voltage. Therefore, the electrode foil is the part of an aluminum electrolytic capacitor that has the highest technical content and added value.

To increase the specific capacitance of electrode foil, three methods are generally considered: improving the corrosion process to increase the surface area ratio (method 1); reducing the average dielectric thickness under the operating voltage (method 2); and improving the properties of the dielectric layer to increase the dielectric constant (method 3). With method 2, the thickness of the dielectric layer depends on the operating voltage, which is usually a fixed value, so it cannot be improved. With method 3, the dielectric constant of the dielectric layer is also a fixed value, so it cannot be improved. Therefore, improving the corrosion process to increase the surface area ratio is the best way to increase the specific capacitance of electrode foil, and this is a topic of research for those skilled in the art.

Therefore, there is currently an urgent need to develop a power supply device, its control method, and a power supply system that overcomes the above drawbacks.

The present invention provides a power supply, a control method thereof, and a power supply system. A control unit detects a signal reflecting the voltage between the working electrode and reference electrode of an electrochemical three-electrode system, compares the signal with a predetermined voltage range, and, based on the comparison result, adjusts the output current of the power unit within the current range to maintain the signal within the voltage range (i.e., between the critical passivation potential and the overpassivation potential) and maintain the output current close to the passivation current. This allows corrosion pits generated at the beginning of etching to continue growing, improving the production efficiency of pit expansion. Furthermore, by adjusting the dynamic characteristics of the low passivation current in real time, the formation of a passivation film on the inner surface of the corrosion pit and corrosion are promoted, effectively developing the corrosion pit in the depth direction, increasing the production efficiency of the working electrode, improving the uniformity of the corrosion pit, and improving the overall specific capacity. At the same time, the remaining thickness of the working electrode after corrosion is maintained uniform, improving the bending characteristics of the working electrode.

To achieve the above object, one embodiment of the present invention provides a control method applied to a power supply device, including the following steps: First, prepare an electrochemical three-electrode system including a working electrode, a reference electrode, and an auxiliary electrode. Next, connect two output terminals of a power unit of the power supply device to the working electrode and the auxiliary electrode, respectively, and the power unit outputs an output current for polarizing the working electrode. Then, a control unit of the power supply device detects a signal reflecting the voltage between the working electrode and the reference electrode and adjusts the output current based on the signal.

To achieve the above object, another embodiment of the present invention provides a power supply device for use in an electrochemical three-electrode system including a working electrode, a reference electrode, and an auxiliary electrode. The power supply device includes a power unit and a control unit. The power unit has two output terminals connected to the working electrode and the auxiliary electrode, respectively, and outputs an output current for polarizing the working electrode. The control unit is used to detect a signal reflecting the voltage between the working electrode and the reference electrode and to adjust the output current based on the signal.

To achieve the above object, another embodiment of the present invention provides a power supply system including the above-mentioned power supply device and an electrochemical three-electrode system.

1 is a structural schematic diagram of a power supply system according to the present invention; 2 is a partially enlarged schematic view showing the structure of a corrosion pit formed in a working electrode of the power supply system shown in FIG. 1 . FIG. 2 is a partially enlarged schematic view showing the structure of an oxide film formed on a working electrode of the power supply system shown in FIG. 1. FIG. FIG. 2B is a simplified schematic diagram of the coaxial capacitance of the corrosion pit shown in FIG. 2A. FIG. 1 is a schematic diagram of the polarization curve of the working electrode of the power supply system when the power voltage is under open-loop control. 3 is a flowchart of a control method for a power supply system according to the present invention. 1. FIG. 4 is a voltage signal-current waveform diagram showing the output current and voltage signals in the third stage of the power supply system shown in FIG. 1. FIG. 4 is a partially enlarged schematic view showing the structure of another embodiment in which corrosion pits are formed in the working electrode of the power supply system shown in FIG. 1. FIG. 4 is a partially enlarged schematic view showing the structure of another embodiment in which corrosion pits are formed in the working electrode of the power supply system shown in FIG.

Several exemplary embodiments illustrating the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention may have various modifications in different aspects, all without departing from the scope of the present invention, and that the description and drawings are intended to be illustrative in nature and not limiting.

Please refer to Figure 1. Figure 1 is a schematic diagram of the structure of the power supply system of the present invention. As shown in Figure 1, the power supply system 1 of the present invention includes a power unit 2, an electrochemical three-electrode system 3, a corrosive liquid 4, and a control unit 5. The power unit 2 has output terminals 22 and 23. The electrochemical three-electrode system 3 includes an auxiliary electrode 31, a working electrode 32, and a reference electrode 33. The auxiliary electrode 31 can be formed of a titanium plate and is connected to the output terminal 22 of the power unit 2. The working electrode 32 can be formed of a high-purity metal foil such as aluminum foil and is connected to the output terminal 23 of the power unit. By receiving the output current supplied from the power unit 2, the working electrode 32 is polarized according to the output current supplied from the power unit 2. The material of the reference electrode 33 is related to the ionic system of the corrosive liquid 4. For example, if the corrosive liquid is a hydrochloric acid or sulfuric acid solution, the electrode 33 can be composed of a saturated calomel electrode (SCE). The working electrode 32 and the auxiliary electrode 31 are disposed in the corrosive liquid 4. The output current supplied from the power unit 2 passes through the working electrode 32, the corrosive liquid 4, and the auxiliary electrode 31 in this order. The reference electrode 33 is at least partially disposed in the corrosive liquid 4. A voltage exists between the working electrode 32 and the reference electrode 33. In an actual process, the working electrode 32, the auxiliary electrode 31, and the reference electrode 33 are immersed in the corrosive liquid 4 in a corrosion bath. However, FIG. 1 only shows the corrosive liquid 4, and does not illustrate the structure of the corrosion bath. The control unit 5, together with the power unit 2, constitutes a power supply. The control unit 5 controls the power unit 2 based on a signal reflecting the voltage between the working electrode 32 and the reference electrode 33. For example, the control unit 5 is connected to the working electrode 32 and the reference electrode 33 of the electrochemical three-electrode system 3, detects a signal reflecting the voltage between the working electrode 32 and the reference electrode 33, and adjusts the output current output by the power unit 2 via the control terminal 21 in response to the signal. The signal reflecting the voltage between the working electrode 32 and the reference electrode 33 correlates with the output current supplied by the power unit 2; this correlation will be described later.

Please refer to Figures 2A and 2B in addition to Figure 1. Figure 2A is a partially enlarged schematic diagram showing the structure of a corrosion pit formed on the working electrode of the power supply system shown in Figure 1, and Figure 2B is a partially enlarged schematic diagram showing the structure of an oxide film formed on the working electrode of the power supply system shown in Figure 1. Figures 2A and 2B both show a portion of the structure within the dotted line frame in Figure 1, for example, a portion of the structure of the contact surface between the working electrode 32 and the corrosive liquid 4 under different conditions. The corrosion process of the working electrode 32 begins as shown in Figure 1: first, the working electrode 32 and auxiliary electrode 31 are placed in the corrosive liquid 4. Next, the power unit 2 supplies an output current to the working electrode 32. At this time, electrons and ions in the corrosive liquid 4 are consumed, and metal ions on the working electrode 32 enter the corrosive liquid 4, forming a corrosion pit 32a in the working electrode 32 (as shown in Figure 2A), and the surface area of the working electrode 32 increases. Thereafter, the power unit 2 continues to supply output current to the working electrode 32, causing an oxidation reaction on the surface of the working electrode 32, forming an oxide film 32b (as shown in Figure 2B). The corrosive liquid 4 then further corrodes the oxide film 32b, enlarging the corrosion pit 32a.

The capacitance per unit area (i.e., specific capacitance) of an aluminum electrolytic capacitor correlates with the state of the corrosion pits 32a formed on the working electrode 32. Please refer to FIG. 3 in addition to FIGS. 1 and 2A. FIG. 3 is a simplified schematic diagram of the coaxial capacitance of the corrosion pits shown in FIG. 2A. The collector capacitance of the distributed capacitances C1, C2, ..., Cn in the diagram is given by: From this equation, it can be seen that the capacitance per unit area of an aluminum electrolytic capacitor correlates with the depth L of the corrosion pits 32a and the radius r1 of the corrosion pits 32a. The greater the depth L of the corrosion pits 32a, the greater the capacitance per unit area of the aluminum electrolytic capacitor; and the greater the radius r1 of the corrosion pits 32a, the greater the capacitance per unit area of the aluminum electrolytic capacitor.

When the working electrode 32 is placed in the corrosive liquid 4, a surface potential is formed on the surface of the working electrode 32. This surface potential is correlated with the nature of the metal, the composition, concentration, and temperature of the corrosive liquid 4. When the output current supplied from the power unit 2 passes through the working electrode 32, the working electrode 32 is polarized, resulting in a change in the electrode potential. That is, the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 is correlated with the output current supplied from the power unit 2. A polarization curve can be further formed based on the correlation between the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 and the output current supplied from the power unit 2. Furthermore, according to two formulas of electrochemical reaction kinetics, namely the Butler-Volmer equation and the Arrhenius equation, factors affecting the galvanic corrosion rate include the polarization potential or polarization current, the composition of the electrolyte, the temperature and concentration of the electrolyte, the corrosion time, the electrode surface condition, and the crystalline structure. Among these, the polarization potential or polarization current, i.e., the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 or the output current supplied from the power unit 2, has the greatest impact. Therefore, hereinafter, we will further examine the correlation between the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 and the output current, and use this correlation to determine the corrosion rate of the working electrode 32. Please refer to FIG. 4 in addition to FIGS. 1, 2A, and 2B. FIG. 4 is a schematic diagram of a polarization curve of the working electrode of a power supply system when the power voltage is under open-loop control. As shown in FIG. 4, the X-axis of the polarization curve represents the signal reflecting the voltage between the working electrode 32 and the reference electrode 33, and the Y-axis of the polarization curve represents the output current supplied from the power unit 2. The signal reflecting the voltage between the working electrode 32 and the reference electrode 33 in the polarization curve includes four sections, for example, a first section, a second section, a third section, and a fourth section, as shown in FIG. 4. In the first section, the power unit 2 starts to supply an output current, and corrosion pits 32a begin to form on the working electrode 32. A chemical reaction also occurs between the working electrode 32 and the corrosive liquid 4, gradually producing an oxide film 32b. The output current supplied from the power unit 2 increases from a first current ip to a second current ib, and as a result, the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 increases from point A to point B. The corrosion rate of the working electrode 32 increases as the output current increases. When the output current supplied from the power unit 2 increases to the second current ib, the corrosion rate of the working electrode 32 reaches a maximum value and the output current cannot continue to increase. Therefore, the second current ib is defined as the critical passivation current. In the second section, the corrosion rate of the working electrode 32 decreases, i.e., the output current supplied from the power unit 2 begins to decrease from the second current ib to the first current ip, and the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 increases from point B to point C. As the output current decreases, the corrosion rate of the working electrode 32 decreases. When the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 increases to point C, the output current supplied from the power unit 2 decreases and is maintained at the first current ip. Therefore, the voltage signal at point C is defined as the critical passivation potential Ep. In the third section, the output current supplied from the power unit 2 is maintained at the first current ip, and the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 increases from point C to point D. At this point, the corrosion rate of the working electrode 32 and the rate of oxide film 32b formation reach a dynamic equilibrium, and the output current is stable at this point. This section is the stable passivation region, so the output current in this section (i.e., the first current ip) is defined as the passivation current. Because the power unit is under open-loop control, the output current in this section is essentially a fixed value. In the fourth section, the output current supplied from the power unit 2 continues to increase from the first current ip, and the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 increases from point D to point E. Another corrosion pit 32a continues to form on the working electrode 32, and the corrosion reaction becomes more intense. Therefore, this section is defined as the overpassivation region.

Because the pit expansion reaction process is highly sensitive to the output current, a decrease in the output current may cause the formation of corrosion pits 32a to stop or the interface where the corrosion pits 32a form to become discontinuous. From the above description of the polarization curve and Figure 4, the third section is the stable growth period of corrosion pits, during which the output current is low and gentle. In this section, the corrosion rate of the working electrode 32 and the formation rate of the oxide film 32b can reach a dynamic equilibrium, resulting in stable growth of corrosion pits 32a. Therefore, to achieve a better corrosion pit expansion effect, the power supply system 1 of the present invention dynamically adjusts the output current via the control unit 5 and monitors the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 so that the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 and the output current are in the stable growth period of corrosion pits in the polarization curve. As shown in FIG. 1, the control unit 5 is electrically connected to the working electrode 32 and the reference electrode 33 of the electrochemical three-electrode system 3. The control unit 5 defines a predetermined voltage and current interval. For example, the voltage interval is the third interval (i.e., between points C and D) shown in FIG. 4. The control unit 5 detects a signal reflecting the voltage between the working electrode 32 and the reference electrode 33 of the electrochemical three-electrode system 3 and adjusts the output current based on the signal. For example, the control unit 5 compares the signal with a predetermined voltage interval and determines whether the signal is within the voltage interval. Depending on the comparison result, the control unit 5 adjusts the output current of the power unit 2 within the current interval to maintain the signal within the voltage interval, i.e., to maintain the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 of the electrochemical three-electrode system 3 within the third interval shown in FIG. 4.

As can be seen from the above, the power supply system 1 of the present invention uses the control unit 5 to detect a signal reflecting the voltage between the working electrode 32 and the reference electrode 33 of the electrochemical three-electrode system 3, compare the signal with a predetermined voltage range, and, based on the comparison result, adjust the output current of the power unit 2 within a current range so as to maintain the signal within the voltage range (i.e., between the critical passivation potential and the overpassivation potential) and the output passivation current within a certain range. This allows the corrosion pits 32a generated at the beginning of etching to continue to grow, improving the production efficiency of pit expansion. Furthermore, by adjusting the passivation current in real time, the formation of a passivation film on the inner surface of the corrosion pits 32a and corrosion are promoted, effectively developing the corrosion pits 32a in the depth direction, increasing the production efficiency of the working electrode 32, improving the uniformity of the corrosion pits 32a, and improving the overall specific capacitance. At the same time, the remaining thickness of the working electrode 32 after corrosion is maintained uniform, improving the bending characteristics of the working electrode 32.

Refer to Figure 5. Figure 5 is a flowchart of a control method for a power supply system of the present invention. First, in step S1, an electrochemical three-electrode system 3 is prepared, including a working electrode 32, a reference electrode 33, and an auxiliary electrode 31. Next, in step S2, the two output terminals 23 and 22 of the power unit 2 are connected to the working electrode 32 and the auxiliary electrode 31, respectively, and the power unit 2 outputs an output current for polarizing the working electrode 32. Then, in step S3, the control unit 5 detects a signal reflecting the voltage between the working electrode 32 and the reference electrode 33 and adjusts the output current based on the signal.

The method for maintaining the signal within a predetermined voltage range is described in more detail below. Please refer to FIG. 6 in conjunction with FIGS. 1 and 4. FIG. 6 is a voltage signal-current waveform diagram showing the output current and voltage signal in the third stage of the power supply system shown in FIG. 1. The Y axis of FIG. 6 is the output current supplied from the power unit 2, and the X axis is a signal reflecting the voltage between the working electrode 32 and the reference electrode 33. Compared to FIG. 4, the passivation current in FIG. 6 is a dynamically adjustable range, while the passivation current in FIG. 4 is essentially a fixed value. In this embodiment, the predetermined current range within the control unit 5 has upper and lower limits, where the upper limit of the current range is , the lower limit of the current range is , and may be equal to or different from , and im is an intermediate value. This current range corresponds to the stable passivation region in the polarization curve shown in FIG. 4. When the control unit 5 detects the signal reflecting the voltage between the working electrode 32 and the reference electrode 33, compares the signal with the voltage interval, and determines that the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 is equal to or less than the lower limit of the voltage interval, the control unit 5 controls the output current supplied by the power unit 2 to decrease, decreasing the output current from a high current value back to im (as shown by "Current Decline" in FIG. 6 ), thereby preventing the corrosion reaction from continuing too quickly under excessive current. The lower limit of the voltage interval reflects the overpassivation potential of the working electrode's polarization curve. The control unit 5 detects a signal reflecting the voltage between the working electrode 32 and the reference electrode 33, compares the signal with the voltage range, and determines that the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 is equal to or greater than the upper limit of the voltage range. The control unit 5 controls the output current provided by the power unit 2 to increase, increasing the output current from a low current value back to im (as shown by "Current Rise" in FIG. 6 ). This shifts the state of the working electrode 32 toward the transition region between metal activation and passivation. This prevents the working electrode 32 from being fully passivated at low currents, which would otherwise affect the corrosion rate of the oxide film 32b. The upper limit of the voltage range reflects the critical passivation potential of the working electrode's polarization curve. As can be seen from the above, the output current provided by the power unit 2 is within the current range and is dynamically adjusted according to the detection result of the signal reflecting the voltage between the working electrode 32 and the reference electrode 33. This ensures that the corrosion state of the corrosion pit 32a of the working electrode 32 of the present invention is within the passive current operating region of the polarization curve, thereby increasing the overall specific capacity. Of course, in one embodiment, the signal reflecting the voltage between the working electrode 32 and the reference electrode 33 may be the voltage value between the working electrode 32 and the reference electrode 33, with the lower limit of the voltage interval being the value of the overpassivation potential of the polarization curve of the working electrode and the upper limit of the voltage interval being the value of the critical passivation potential of the polarization curve of the working electrode.

In some embodiments, the output current provided by the power unit 2 has a hysteresis effect on the signal reflecting the voltage between the working electrode 32 and the reference electrode 33. As shown in FIG. 6, for example, when the control unit 5 controls the increase in the output current provided by the power unit 2, the output current can have a variable duty cycle and a variable current change rate, and the output current can be a continuous current waveform or a discrete current waveform. The corresponding voltage when the output current is in the increasing state can be different from the corresponding voltage when the output current is in the decreasing state, and can have a voltage difference value Vd.

Please refer to Figures 7A and 7B in conjunction with Figure 1. Figures 7A and 7B are partially enlarged schematic diagrams illustrating the structure of another embodiment of forming corrosion pits on the working electrode of the power supply system shown in Figure 1. As shown in Figure 7A, the working electrode 32 is further provided with a corrosion inhibitor 32c that blocks a portion of the working electrode 32 from the corrosive liquid 4, thereby mitigating excessive corrosion on the surface of the working electrode 32, effectively controlling the pit coalescence phenomenon, favoring the uniform distribution of corrosion pits 32a on the surface of the working electrode 32, reducing damage to the pit walls of the corrosion pits 32a, and deepening the corrosion tunnels. In addition, a portion of the current component (i2) of the output current supplied from the power unit 2 directly corrodes the working electrode 32 through the corrosion pits 32a, while another current component (i1) of the output current must corrode the working electrode 32 via the corrosion inhibitor 32c. That is, current component i2 in the output current supplied from the power unit 2 becomes larger than current component i1, and the corrosive liquid 4 corrodes the corrosion pits 32a precisely, increasing corrosion efficiency. Furthermore, by increasing the volume of the corrosion pits 32a, i.e., changing the size of the corrosion pits 32a from that shown in FIG. 7A to that shown in FIG. 7B, the effect of improving the overall specific capacity is achieved. The shape of the corrosion pits 32a may be conical, cylindrical, pot-shaped, or the like.

As described above, the power supply system of the present invention uses a control unit to detect a signal reflecting the voltage between the working electrode and reference electrode of an electrochemical three-electrode system, compare the signal with a predetermined voltage range, and, based on the comparison result, maintain the signal within the voltage range (i.e., between the critical passivation potential and the overpassivation potential) by adjusting the output current of the power unit within the current range so as to maintain the output current close to the passivation current. This allows corrosion pits that occur early in etching to continue to grow, improving the production efficiency of pit expansion. Furthermore, by adjusting the dynamic characteristics of the low passivation current in real time, the formation of a passivation film on the inner surface of the corrosion pit and corrosion are promoted, effectively developing the corrosion pit in the depth direction, increasing the production efficiency of the working electrode, improving the uniformity of the corrosion pit, and improving the overall specific capacitance. At the same time, the residual thickness of the working electrode after corrosion is maintained uniform, improving the bending characteristics of the working electrode.

1: Power supply system 2: Power unit 21: Control terminal 22, 23: Output terminal 3: Electrochemical three-electrode system 31: Auxiliary electrode 32: Working electrode 32a: Corrosion pit 32b: Oxide film 32c: Corrosion inhibitor 33: Reference electrode 4: Corrosive liquid 5: Control unit L: Depth r1: Radius ip: First current ib: Second current S1, S2, S3: Steps

Claims (18)

A control method applied to a power supply device,
(a) providing an electrochemical three-electrode system including a working electrode, a reference electrode, and an auxiliary electrode;
(b) connecting two output terminals of a power unit of the power supply device to the working electrode and the auxiliary electrode, respectively, and causing the power unit to output an output current for polarizing the working electrode;
(c) a control unit of the power supply detecting a signal reflecting a voltage between the working electrode and the reference electrode and adjusting the output current based on the signal ;
The output current has a hysteresis effect on the signal .
Control method. The control method of claim 1, wherein step (c) further includes comparing the signal with a predetermined voltage interval and, depending on the comparison result, adjusting the output current within the predetermined current interval so as to maintain the signal within the predetermined voltage interval. When the signal is equal to or lower than the lower limit of the voltage range, the control unit controls the output current to decrease;
The control method according to claim 2 , wherein the control unit controls the output current to increase when the signal is equal to or greater than the upper limit of the voltage section. 4. The method of claim 3, wherein the upper limit of the voltage interval reflects a overpassivation potential of a polarization curve of the working electrode, and the lower limit of the voltage interval reflects a critical passivation potential of the polarization curve. 5. The method of claim 4, wherein the signal is a voltage between the working electrode and the reference electrode, the upper limit of the voltage interval is the overpassivation potential of the polarization curve of the working electrode, and the lower limit of the voltage interval is the critical passivation potential of the polarization curve. The control method described in claim 2, wherein the current section corresponds to a stable passivation region of the polarization curve of the working electrode. The control method of claim 1 further includes, between steps (a) and (b), a step of providing a corrosion inhibitor on the working electrode to isolate a portion of the working electrode from the corrosive liquid. The control method described in claim 1, wherein the working electrode is a metal foil, the auxiliary electrode is a titanium plate, and the reference electrode is a saturated calomel electrode. 1. A power supply for use in an electrochemical three-electrode system including a working electrode, a reference electrode, and an auxiliary electrode, comprising:
a power unit having two output terminals connected to the working electrode and the auxiliary electrode, respectively, and outputting an output current for polarizing the working electrode;
a control unit that detects a signal reflecting a voltage between the working electrode and the reference electrode and adjusts the output current based on the signal ;
The output current has a hysteresis effect on the signal .
power supply. 10. The power supply device of claim 9, wherein the control unit compares the signal with a predetermined voltage interval and, depending on the comparison result , adjusts the output current within a predetermined current interval so as to maintain the signal within the predetermined voltage interval. When the signal is equal to or lower than the lower limit of the voltage range, the control unit controls the output current to decrease;
The power supply device according to claim 10 , wherein the control unit controls the output current to increase when the signal is equal to or greater than an upper limit value of the voltage section. 12. The power supply of claim 11 , wherein the upper limit of the voltage interval reflects a overpassivation potential of a polarization curve of the working electrode, and the lower limit of the voltage interval reflects a critical passivation potential of the polarization curve . 13. The power supply of claim 12, wherein the signal is a voltage value between the working electrode and the reference electrode, the upper limit of the voltage interval is a value of the overpassivation potential of the polarization curve of the working electrode, and the lower limit of the voltage interval is a value of the critical passivation potential of the polarization curve . 11. The power supply of claim 10 , wherein the current section corresponds to a stable passivation region of a polarization curve of the working electrode. 10. The power supply of claim 9 , wherein the output current has a hysteresis effect on the signal. 10. The power supply of claim 9 , wherein the working electrode is provided with a corrosion inhibitor to isolate a portion of the working electrode from a corrosive liquid. 10. The power supply device of claim 9 , wherein the working electrode is a metal foil, the auxiliary electrode is a titanium plate, and the reference electrode is a saturated calomel electrode. A power supply system comprising the power supply device according to any one of claims 9 to 17 and an electrochemical three-electrode system.