Method for regulating and controlling performance of two-port solar charging device through electrolyte

Abstract

The invention discloses a method for regulating and controlling the performance of a two-port solar charging device through electrolyte, and the method comprises the following steps: S1, enabling a conductive polymer to be supported on the surface of a light-absorbing semiconductor material through a photoelectric deposition method to form an energy storage layer of a photo-anode, the energy storage layer is one or a compound of more than two of polyacetylene, polyaniline, polypyrrole, polymethylpyrrole and the like; and S2, selecting Si as a light absorption semiconductor layer of the photo-anode. According to the invention, the design is reasonable, the HClO4 electrolyte is selected to replace the traditional H2SO4, H3PO4 and HCl electrolyte, and the charge-discharge current and the light output voltage are more excellent than those of the traditional electrolyte. A basic device structure is selected, a photoelectrode is composed of two parts, namely n-Si serving as a light absorption layer and polymethylpyrrole (PNMPy) serving as an energy storage layer, WO3 is selected as a counter electrode, an electrolyte is replaced by HClO4 from traditional H2SO4, H3PO4 and HCl, and the formed device has long-term stability.

Description

Technical Field

[0001] The invention relates to the technical field of solar-powered rechargeable devices, and in particular to a method for regulating the performance of a two-port solar-powered charging device using an electrolyte. Background Art

[0002] In order to achieve the goal of carbon peak and carbon neutrality, the full utilization of solar energy resources has become an inevitable trend, and the development of low-cost solar energy utilization technology has become a key research area in my country for some time to come. Due to factors such as day and night rain, solar cells cannot continuously supply energy, so the development of higher-performance solar energy storage devices can effectively solve the problem of solar energy storage.

[0003] There are many performance limiting factors for existing two-port solar charging devices, and most of the control methods start from the photoanode or the counter electrode. In addition, the commonly used electrolytes are mainly alkaline and neutral. The cycle performance of the devices in these two types of electrolytes is poor. At present, there is little understanding of acidic electrolytes. The commonly used acid is sulfuric acid. ( H 2 SO 4 ),hydrochloric acid ( HCl ) 、 Phosphoric acid ( H 3 PO 4 ), which limits the further development of two-port devices. To this end, the present application proposes a method for regulating the performance of a two-port solar charging device with an electrolyte. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to propose a method for regulating the performance of a two-port solar charging device by electrolyte, which can improve the performance of semiconductor / energy storage material photoanode to achieve a higher performance solar photocharging device.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for regulating the performance of a two-port solar charging device by an electrolyte, comprising the following steps:

[0007] S1, making the conductive polymer supported on the surface of the light-absorbing semiconductor material by photoelectric deposition to form an energy storage layer of the photoanode, wherein the energy storage layer is one or a composite of two or more of polyacetylene, polyaniline, polypyrrole, polymethylpyrrole, etc.;

[0008] S2, selecting Si as the light-absorbing semiconductor layer of the photoanode;

[0009] S3, HClO 4 As electrolyte;

[0010] S4. Select one of oxide semiconductors and polymers as a counter electrode to construct a two-port light-charged dark-discharge device, so that the constructed device can achieve light-charged dark-discharge under zero bias, and further expand to a quasi-solid-state device.

[0011] Preferably, the energy storage layer of the photoanode is polymethylpyrrole.

[0012] Preferably, the light-absorbing semiconductor layer of the photoanode is n-Si.

[0013] Preferably, the n-Si is n-type planar silicon.

[0014] Preferably, the pH of the electrolyte is 0.

[0015] Preferably, the HClO 4 1M HClO 4 .

[0016] Preferably, the counter electrode is made of WO 3 constitute.

[0017] Preferably, the HClO 4 The solution is dissolved in polyvinyl alcohol hydrogel and then dripped between the photoanode and the counter electrode to form a gel at room temperature to form a quasi-solid-state device.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] In the method for regulating the performance of a two-port solar charging device, HClO is selected 4 The electrolyte replaces the traditional H 2 SO 4 , H 3 PO 4 , HCl electrolyte, showing superior charge and discharge current and light output voltage compared to traditional electrolytes. A basic device structure was selected, in which the photoelectrode consists of two parts, n-Si as the light absorption layer and polymethylpyrrole (PNMPy) as the energy storage layer, and WO is selected as the counter electrode. 3 The electrolyte is composed of the traditional H 2 SO 4 , HCl and H 3 PO 4 Replace with HClO with pH = 0 4 , the device constructed has long-term stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the SEM image of polymethylpyrrole supported on n-Si;

[0021] Figure 2 The photocharge and dark discharge cyclic voltammetry curves of n-Si / PNMPy in different acidic electrolytes;

[0022] Figure 3 The time-current curves of light charging and dark discharge of n-Si / PNMPy in different acidic electrolytes;

[0023] Figure 4 Liquid device n-Si / PNMPy / electrolyte / WO 3 Schematic diagram of the device structure;

[0024] Figure 5 Long-term time-current curves of liquid devices in different acidic electrolytes;

[0025] Figure 6 This is the long-term time-current curve of the liquid device at 0V in different acidic electrolytes;

[0026] Figure 7 The voltage response of the liquid device to alternating light charging and dark discharge in different acidic electrolytes;

[0027] Figure 8 Quasi-solid-state device n-Si / PNMPy / PVA-acid electrolyte / WO 3 Schematic diagram of the device structure;

[0028] Fig. 9 The photo-charging and dark-discharging cyclic voltammetry curves of the quasi-solid-state device in different acidic electrolytes;

[0029] Fig.10 The long-term time-current curve of the quasi-solid-state device at 0V in different acidic electrolytes;

[0030] Fig.11 The voltage response of the quasi-solid-state device to alternating light charging and dark discharge in different acidic electrolytes. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] Reference Figure 1-Figure 11 A method for regulating the performance of a two-port solar charging device by using an electrolyte. A two-port solar rechargeable device is used. The light charging and dark discharge characteristics of the photoanode are improved by using a simple electrolyte on the semiconductor / energy storage material heterojunction. Then, a suitable counter electrode is selected to achieve a device with higher performance than that of a traditional acidic electrolyte.

[0033] The following steps are involved:

[0034] S1, making the conductive polymer supported on the surface of the light-absorbing semiconductor material by photoelectric deposition to form an energy storage layer of the photoanode, wherein the energy storage layer is one or a composite of two or more of polyacetylene, polyaniline, polypyrrole, polymethylpyrrole, etc., and preferably the energy storage layer of the photoanode is polymethylpyrrole;

[0035] S2, selecting Si as the light-absorbing semiconductor layer of the photoanode, specifically, the light-absorbing semiconductor layer of the photoanode is n-Si, and the n-Si is n-type flat silicon, to obtain a photoanode composed of n-Si and polymethylpyrrole (PNMPy);

[0036] S3, HClO 4 As electrolyte, HClO 4 1M HClO 4 , the pH of the electrolyte is 0. In the three-electrode system, under sunlight, when an oxidation potential is applied, the photogenerated holes in the n-Si oxidize the polymethylpyrrole layer, generating an oxidation current, and the anions in the solution react with the conductive polymer;

[0037] S4. Select one of the oxide semiconductors and polymers as the counter electrode to construct a two-port light-charged dark-discharge device, so that the constructed device can realize light-charged dark-discharge under zero bias, and further expand to quasi-solid-state devices. Specifically, the liquid electrolyte is replaced with a quasi-solid electrolyte. The quasi-solid electrolyte selected is polyvinyl alcohol (PVA), that is, HClO 4 The solution is dissolved in polyvinyl alcohol hydrogel and then dripped between the photoanode and the counter electrode to form a gel at room temperature to form a quasi-solid-state device.

[0038] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0039] Implementation 1

[0040] Prepare the polymethylpyrrole (PNMPy) deposition precursor solution by dissolving 1 mL of methylpyrrole (N-Py) monomer in 0.1 M NaCl solution. Cut the silicon wafer into 1*1 cm 2 size, respectively, with acetone and deionized water (volume ratio H 2 SO 4 :H 2 O 2 =3:1 mixed solution) ultrasonic cleaning for 10 min. Soak in 5% HF solution for 30 s to remove surface SiO 2 The silicon wafer was then sealed with silicone and left to stand for 24 hours at room temperature until the silicone solidified. The sealed silicon wafer was immersed in 5% HF for 150 seconds to remove the surface SiO2 After drying, 200 mC PNMPy was deposited on the surface of the silicon wafer using a 0.4 V potential in a three-electrode system. Figure 1 ) It can be seen that the PNMPy loaded on the silicon wafer is distributed in a spherical shape with a diameter of about 500nm.

[0041] Prepare HClO 4 ), sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl), phosphoric acid (H 3 PO 4 ) electrolyte. Using three electrodes, Si / PNMPy was used as the working electrode, Ag / AgCl was used as the reference electrode, and C rod was used as the counter electrode. First, the Si / PNMPy was subjected to a cyclic voltammetry (CV) test of light charging and dark discharge (refer to Figure 2 ), at -0.2V RHE When the positive scanning is carried out, the 0.05V RHE Photocurrent begins to be generated, and in sulfuric acid, hydrochloric acid and phosphoric acid electrolytes to 0.25V RHE A photocurrent is generated, and the turn-on potential in perchloric acid electrolyte is 0.2 V earlier than that in other acids. RHE , at 0.6V RHE When the light is turned off and reverse scan is performed, dark current will be generated in all four electrolytes. The dark current in perchloric acid is larger than that in the other three acids. The light charging and dark discharge in the four acids are reversible. RHE Time-current (it) test of Si / PNMPy (refer to Figure 3 ), in perchloric acid electrolyte at 0.3V RHE The photocharging current density reaches 2.85 mA / cm 2 , while in sulfuric acid, hydrochloric acid, and phosphoric acid, the values ​​are only 0.5, 0.4, and 0.2 mA / cm 2 The dark discharge current density in perchloric acid electrolyte reaches 1.11 mA / cm 2 , while in sulfuric acid, hydrochloric acid, and phosphoric acid, the values ​​are only 0.3, 0.18, and 0.1 mA / cm 2 It can be seen that the photocurrent and dark current intensities in perchloric acid are greater than those in the other three acids. The photocharging current in perchloric acid electrolyte can reach 2.5 mA / cm 2 Above, dark current can reach 1mA / cm 2 The above is about five times the light charging current of the other three acids, and about three times the dark discharge current.

[0042] Implementation 2

[0043] Cut FTO into 1*2cm 2The size was ultrasonically cleaned with acetone, deionized water, and ethanol for 30 minutes each, and then the WO deposition 3 The precursor solution is 0.08 MH 2 O 2 、0.36MH 2 SO 4 and 0.1M Na 2 WO 4 ·2H 2 O was dissolved in deionized water, and WO was electrochemically oxidized and deposited on FTO using a three-electrode system with a deposition potential of -0.5 V. 3 , the deposition amount is 100mC, and then it is constructed with Si / PNMPy into a two-port device. The device structure is as follows Figure 4 The electrochemical workstation was used to test the voltage from -0.3V to 0.3V when the light was on, and then the voltage was turned off and the voltage was tested from 0.3V to -0.3V. The cyclic voltammetry (CV) curve is shown in the figure. Figure 5 As shown in the figure, it can be seen that from perchloric acid to sulfuric acid, hydrochloric acid, phosphoric acid, the light charging current and dark discharge current gradually decrease. The time-current (it) curve at 0V (refer to Figure 6 ) was tested, and the charging current in perchloric acid electrolyte can reach 1.4mA / cm 2 , while in sulfuric acid, hydrochloric acid, and phosphoric acid, the values ​​are only 0.4, 0.37, and 0.25 mA / cm 2 The discharge current in perchloric acid electrolyte can reach 0.3 mA / cm2, while in sulfuric acid, hydrochloric acid, and phosphoric acid, it is only 0.06, 0.1, and 0.08 mA / cm 2 , it can be seen that the current in perchloric acid is much larger than that in the other three acids, and the photovoltage can reach 0.4V, which is higher than that in the other three acids.

[0044] The liquid electrolyte was dissolved in PVA gel (polyvinyl alcohol hydrogel), that is, PVA and deionized water were added into a beaker in a ratio of 1:10, and the mixture was placed in an oil bath at 85°C for 2 hours, and then the diluted acidic electrolyte with a pH of 0 was added dropwise, stirred evenly, and added dropwise to the counter electrode WO. 3 The photoanode was glued on and dried for 24 hours before the photoelectrochemical test. The photocharge dark discharge cyclic voltammetry curve (CV) is shown in Fig. 9 As shown, it can be seen that the charge and discharge currents in perchloric acid are higher than those in the other three acids, and the time-current test is performed at 0V (refer to Fig.10 ) It can be seen that its photocurrent and dark current are higher than those of the other three acids. The device constructed based on perchloric acid can perform photocharging and dark discharge without bias, and has long-term stability and a high output voltage.

[0045] Combining Example 1 and Example 2, it can be seen that HClO 4The electrolyte replaces the traditional H 2 SO 4 , H 3 PO 4 HCl electrolyte, showing superior charge and discharge current and light output voltage compared to traditional electrolytes, and still having these characteristics after being constructed into liquid and quasi-solid devices. The photoelectrode is composed of n-Si as the light absorption layer and polymethylpyrrole (PNMPy) as the energy storage layer, and WO is selected as the counter electrode. 3 The electrolyte consists of traditional H 2 SO 4 , H 3 PO 4 , HCl is replaced by HClO, and the constructed device has long-term stability.

[0046] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for regulating the performance of a two-port solar charging device by electrolyte, characterized in that: The following steps are involved: S1, making the conductive polymer supported on the surface of the light-absorbing semiconductor material by photoelectric deposition to form an energy storage layer of the photoanode, wherein the energy storage layer is one or a composite of two or more of polyacetylene, polyaniline, polypyrrole, polymethylpyrrole, etc.; S2, selecting Si as the light-absorbing semiconductor layer of the photoanode; S3, HClO4 is selected as the electrolyte; S4. Select one of oxide semiconductors and polymers as a counter electrode to construct a two-port light-charged dark-discharge device, so that the constructed device can achieve light-charged dark-discharge under zero bias, and further expand to a quasi-solid-state device.

2. A method for regulating the performance of a two-port solar charging device using an electrolyte according to claim 1, characterized in that: The energy storage layer of the photoanode is polymethylpyrrole.

3. The method for controlling the performance of a two-port solar charging device by using an electrolyte according to claim 1, characterized in that: The light-absorbing semiconductor layer of the photoanode is n-Si.

4. A method for regulating the performance of a two-port solar charging device using an electrolyte according to claim 3, characterized in that: The n-Si is n-type planar silicon.

5. The method for controlling the performance of a two-port solar charging device by using an electrolyte according to claim 1, characterized in that: The pH of the electrolyte is 0.

6. The method for controlling the performance of a two-port solar charging device by using an electrolyte according to claim 1, characterized in that: The HClO4 is 1M HClO4.

7. The method for controlling the performance of a two-port solar charging device by using an electrolyte according to claim 1, characterized in that: The counter electrode is composed of WO3.

8. The method for controlling the performance of a two-port solar charging device by using an electrolyte according to claim 1, characterized in that: The HClO4 solution is dissolved in a polyvinyl alcohol hydrogel and then dripped between the photoanode and the counter electrode to form a gel at room temperature to form a quasi-solid-state device.

Images