A fully solid-state two-port solar rechargeable device

Abstract

The present invention discloses a fully solid-state two-port solar rechargeable device, which is made of the following materials: a photoanode, the photoanode is made by compounding a semiconductor light-absorbing material and an energy storage material; a solid electrolyte, the solid electrolyte has stable ion transport at room temperature, and stable thermal, chemical and electrochemical properties; a counter electrode, the counter electrode can work stably under the corresponding solid electrolyte conditions, and its electrochemical window position and dark-state open-circuit potential meet the requirements of the photoanode. The fully solid-state two-port solar rechargeable device provided by the present invention has greatly improved stability compared with devices in a liquid system by adopting a fully solid-state device.

Description

Technical Field

[0001] The present invention relates to the field of solar rechargeable devices, and particularly to a all-solid-state two-port solar rechargeable device. Background Art

[0002] To achieve China's dual-carbon goal, making full use of solar energy technology is an effective way, and developing low-cost solar energy utilization technology will become a key research area in China in the coming period. Due to factors such as day and night, rain and shine, solar cells cannot continuously supply energy. Developing low-cost solid-state solar storage devices can effectively solve the problem of large-scale solar energy storage. All-solid-state devices have significant advantages in their thermal performance, chemical and electrochemical stability, mechanical strength, stable ion transport, etc., providing the possibility for building integrated and flexible devices in the future.

[0003] At present, two-port solar charging devices cannot be solidified, which hinders their further commercial application. Moreover, two-port solar charging devices mostly use neutral or slightly alkaline electrolytes. The performance of all-solid-state solar charging devices constructed with neutral or alkaline electrolytes decreases significantly compared with the liquid system, and the stability is poor. Therefore, there is an urgent need for an all-solid-state two-port solar rechargeable device to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide an all-solid-state two-port solar rechargeable device to solve the above deficiencies in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An all-solid-state two-port solar rechargeable device is made of the following materials:

[0007] A photoanode, which is made by compounding a semiconductor light-absorbing material and a energy storage material;

[0008] A solid electrolyte, which has stable ion transport at room temperature and stable thermal, chemical and electrochemical properties;

[0009] A counter electrode, which can work stably under the corresponding solid electrolyte conditions, and its electrochemical window position and dark-state open-circuit potential meet the requirements of the photoanode.

[0010] In another embodiment provided by the present invention, the semiconductor light-absorbing material includes one or two semiconductors such as Si, TiO 2 , Fe 2 O 3 .

[0011] In another embodiment provided by the present invention, the energy storage material includes metal oxides, metal hydroxides, sulfides, carbon materials, polymers, etc. The electrochemical window position of the adopted energy storage material matches that of the semiconductor light-absorbing material, and it is required to be at a more positive position of the n-type semiconductor or a more negative position of the p-type semiconductor.

[0012] In another embodiment provided by the present invention, the photoanode can absorb light in a back-illuminated manner or a front-illuminated manner. When using front-illuminated light absorption, one of the counter electrode and the solid electrolyte is made of a transparent or semi-transparent material.

[0013] In another embodiment provided by the present invention, the photoanode is an n-type flat silicon polymer composite photoanode. The photoanode deposits the polymer energy storage material polypyrrole (PPy) or the polymer energy storage material poly-N-methylpyrrole (PNMPy) on the surface of the n-type flat silicon by means of photoelectrochemical deposition and oxidative polymerization.

[0014] In another embodiment provided by the present invention, the fabrication of the n-type flat silicon polymer photoanode includes the following steps:

[0015] A1. Prepare the photoelectrochemical deposition precursor solution: Dissolve 1M NaCl, 0.1M PPy or 0.1M PNMPy in deionized water to obtain the photoelectrochemical deposition precursor solution;

[0016] A2. Remove the oxide layer on the surface of n-Si: Immerse the packaged n-Si in a 5% HF solution for 30 s to remove the surface oxide layer;

[0017] A3. Deposit the PPy film or PNMPy film by three-electrode method: Use n-Si as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode;

[0018] A4. Use the precursor solution as the electrolyte and an AM1.5G (100 mW / cm -2 ) solar simulator as the light source; Utilize the constant voltage test mode of the electrochemical workstation to deposit 200 mC / cm 2 at a potential of 0.4 V vs Ag / AgCl to obtain the n-type flat silicon polymer photoanode.

[0019] In another embodiment provided by the present invention, the counter electrode is a transparent tungsten oxide (WO 3 ) counter electrode, which is characterized by including the following fabrication steps:

[0020] B1. Clean the FTO: Ultrasonically clean it with acetone, ethanol, and deionized water for 30 min respectively, and then dry it;

[0021] B2. Prepare the electrodeposition solution: Mix 0.08M H 2 O 2, 0.36 MH 2 SO 4 and 0.1 M Na 2 WO 4 ·2H 2 O is dissolved in deionized water to serve as a precursor solution;

[0022] B3. Using FTO as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode, and using the precursor solution described in B2 above as the electrolyte; using the constant voltage test mode of an electrochemical workstation, deposit 100 mC / cm at a potential of -0.5 V vs Ag / AgCl 2 , to obtain WO 3 transparent counter electrode.

[0023] In another embodiment provided by the present invention, it includes the preparation of a solid electrolyte: Add 1 g of PVA to 10 mL of deionized water, stir slowly at a heating state of 85 °C for 2 h, and after slightly cooling, dropwise add 1 g of H 2 SO 4 , to obtain a quasi-solid electrolyte.

[0024] In another embodiment provided by the present invention, the prepared quasi-solid electrolyte is dropped on the prepared photo-electrode, and then the counter electrode is adhered, and left for 12 h to obtain a fully solid-state two-port solar rechargeable device.

[0025] In the above technical solution, the present invention provides a fully solid-state two-port solar rechargeable device. The fully solid-state device has greatly improved stability compared to the device of the liquid system. At the same time, the present invention also has the following advantages: (1) The fully solid-state device has a wider application scenario compared to the device of the liquid system; (2) The structure is simple. Compared with the three-port and four-port devices, the two-port device avoids frequent port switching and is more convenient to operate. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of a fully solid-state two-port solar rechargeable device.

[0028] Figure 2 It is the front and side physical diagrams of a fully solid-state solar rechargeable device composed of an n-Si / PNMPy photoanode, a solid electrolyte, and a WO 3 transparent counter electrode.

[0029] Figure 3 SEM images of the surface and cross-section of the photoanode of n-Si supported with PNMPy.

[0030] Figure 4 Cyclic voltammograms of FTO / PPy and FTO / PNMPy for testing the position of the electrochemical window in a three-electrode system

[0031] Figure 5 Photocurrent-charge / discharge voltammetry cycling curves of the n-Si / PNMPy photoanode tested in a three-electrode system.

[0032] Figure 6 For WO 3 Voltammetry curves and open-circuit voltage positions of the counter electrode tested in a three-electrode system.

[0033] Figure 7 For the n-Si / PNMPy photoanode, solid-state electrolyte, WO 3 Photocurrent-charge / discharge voltammetry curves of the all-solid-state solar rechargeable device composed of a transparent counter electrode.

[0034] Figure 8 For the n-Si / PNMPy photoanode, solid-state electrolyte, WO 3 Photocurrent-charge / discharge current curves of the all-solid-state solar rechargeable device composed of a transparent counter electrode.

[0035] Figure 9 For the n-Si / PNMPy photoanode, solid-state electrolyte, WO 3 Long-term photocurrent-charge / discharge current curves of the all-solid-state solar rechargeable device composed of a transparent counter electrode.

[0036] Figure 10 For the n-Si / PNMPy photoanode, liquid electrolyte, WO 3 Long-term photocurrent-charge / discharge current curves of the solar rechargeable device composed of a transparent counter electrode. Detailed implementation manners

[0037] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] As Figure 1-10 shown, an all-solid-state two-port solar rechargeable device provided by an embodiment of the present invention is made of the following materials:

[0039] A photoanode, which is made by compounding a semiconductor light-absorbing material with an energy storage material;

[0040] The solid electrolyte has stable ion transport at room temperature, and has stable thermal, chemical and electrochemical properties;

[0041] The counter electrode can work stably under the corresponding solid electrolyte conditions, and its electrochemical window position and dark state open circuit potential meet the requirements of the photoanode.

[0042] In another embodiment provided by the present invention, the semiconductor light-absorbing material includes one or two semiconductors such as Si, TiO 2 , Fe 2 O 3 and so on.

[0043] In another embodiment provided by the present invention, the energy storage material includes metal oxides, metal hydroxides, sulfides, carbon materials, polymers, etc. The electrochemical window position of the energy storage material used matches that of the semiconductor light-absorbing material, and it needs to be at a more positive position of the n-type semiconductor or a more negative position of the p-type semiconductor.

[0044] In another embodiment provided by the present invention, the photoanode can absorb light in a back-illuminated manner or a front-illuminated manner. When using front-illuminated light absorption, one of the transparent or semi-transparent materials is used for the counter electrode and the solid electrolyte.

[0045] In another embodiment provided by the present invention, the photoanode is an n-type flat silicon polymer composite photoanode, and the photoanode deposits the polymer energy storage material polypyrrole PPy or the polymer energy storage material poly-N-methylpyrrole PNMPy on the surface of the n-type flat silicon by means of photoelectrochemical deposition and oxidation polymerization.

[0046] In another embodiment provided by the present invention, the fabrication of the n-type flat silicon polymer photoanode includes the following steps:

[0047] A1. Prepare the photoelectrochemical deposition precursor solution: Dissolve 1M NaCl, 0.1M PPy or 0.1M PNMPy in deionized water as the photoelectrochemical deposition precursor solution;

[0048] A2. Remove the oxide layer on the surface of n-Si: Immerse the packaged n-Si in 5% HF solution for 30 s to remove the surface oxide layer;

[0049] A3. Deposit the PPy film or PNMPy film with three electrodes: Use n-Si as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode;

[0050] A4. Use the precursor solution as the electrolyte and an AM1.5G (100 mW / cm -2 ) solar simulator as the light source; Using the constant voltage test mode of the electrochemical workstation, deposit 200 mC / cm at a potential of 0.4 V vs Ag / AgCl 2, an n-type flat silicon polymer photoanode is obtained.

[0051] In another embodiment provided by the present invention, the counter electrode is a transparent tungsten oxide (WO 3 ), and the counter electrode is characterized by including the following manufacturing steps:

[0052] B1. Clean the FTO: Ultrasonically clean it with acetone, ethanol, and deionized water for 30 minutes respectively, and then dry it.

[0053] B2. Prepare the electrodeposition solution: Dissolve 0.08 M H 2 O 2 , 0.36 M H 2 SO 4 and 0.1 M Na 2 WO 4 ·2H 2 O in deionized water as the precursor solution.

[0054] B3. Use the FTO as the working electrode, Ag / AgCl as the reference electrode, a carbon rod as the counter electrode, and the above-mentioned B2 precursor solution as the electrolyte; utilize the constant voltage test mode of the electrochemical workstation to deposit 100 mC / cm 2 at a potential of -0.5 V vs Ag / AgCl to obtain a WO 3 transparent counter electrode.

[0055] In another embodiment provided by the present invention, the preparation of the solid electrolyte is included: Add 1 g of PVA to 10 mL of deionized water, stir it at a low speed for 2 hours under heating at 85 °C, and slowly add 1 g of H 2 SO 4 after slightly cooling to obtain a quasi-solid electrolyte.

[0056] In another embodiment provided by the present invention, the prepared quasi-solid electrolyte is dropped on the prepared photoanode, and then the counter electrode is adhered, and it is left for 12 hours to obtain a fully solid-state two-port solar rechargeable device.

[0057] In another embodiment provided by the present invention, when the n-type flat silicon-based photoanode is photo-charged, electron-hole pairs are quickly generated by n-Si light absorption. Among them, holes react with ions in the solid electrolyte on the polymer through a Faraday reaction, and electrons reach the counter electrode through the external circuit and react with ions in the solid electrolyte on the counter electrode through a Faraday reaction. During dark discharge, the reverse process of the corresponding Faraday reaction occurs on the polymer and the counter electrode to achieve the function of discharging to the external circuit load.

[0058] Example 1

[0059] In this embodiment, a photoanode is constructed by supporting PNMPy on n-Si through photoelectrodeposition, and WO is supported on FTO through electrodeposition. 3 A transparent counter electrode is constructed. Using Ag / AgCl as the reference electrode, a carbon rod as the counter electrode, and 0.5 M H 2 SO 4 solution, the photoanode and the transparent counter electrode are used as the working electrodes respectively to construct a three-electrode test system. Through the connection of a solid electrolyte, the n-type flat silicon-based photoanode and the transparent counter electrode are connected to construct a all-solid-state two-port solar rechargeable device.

[0060] The all-solid-state two-port solar rechargeable device includes the following steps:

[0061] Step 1: Prepare the photoelectrodeposition solution: Dissolve 1 M NaCl and 0.1 M PNMPy in deionized water as the photoelectrodeposition precursor solution;

[0062] Step 2: Remove the surface oxide layer of n-Si: Immerse the packaged n-Si in 5% HF solution for 30 s to remove the surface oxide layer;

[0063] Step 3: Deposit the PNMPy film on the three electrodes: Use n-Si as the working electrode, Ag / AgCl as the reference electrode, a carbon rod as the counter electrode, and the precursor solution described in Step 1 as the electrolyte, and use an AM1.5G (100 mW / cm -2 ) solar simulator as the light source; Using the constant voltage test mode of an electrochemical workstation, deposit at a potential of 0.4 V vs Ag / AgCl for 200 mC / cm 2 to obtain an n-type flat silicon-based photoanode;

[0064] Step 4: Clean the FTO: Ultrasonically clean it with acetone, ethanol, and deionized water for 30 min respectively, and then dry it;

[0065] Step 5: Prepare the electrodeposition solution: Dissolve 0.08 M H 2 O 2 , 0.36 M H 2 SO 4 and 0.1 M Na 2 WO 4 ·2H 2 O in deionized water as the precursor solution;

[0066] Step 6: Use FTO as the working electrode, Ag / AgCl as the reference electrode, a carbon rod as the counter electrode, and the precursor solution described in Step 2 as the electrolyte; Using the constant voltage test mode of an electrochemical workstation, deposit at a potential of -0.5 V vs Ag / AgCl for 100 mC / cm 2 to obtain WO 3Transparent counter electrode;

[0067] Step 7: Preparation of quasi-solid electrolyte: Add 1 g of PVA to 10 mL of deionized water, stir at low speed for 2 h under heating at 85 °C, and slowly add 1 g of H 2 SO 4 drop by drop after slightly cooling to obtain a quasi-solid electrolyte;

[0068] Step 8: Assembly of the whole device: Drop the quasi-solid electrolyte described in Step 1 onto the prepared photoanode, attach the counter electrode, and let it stand for 12 h to obtain a fully solid-state two-port solar rechargeable device.

[0069] Please refer to Figure 2 , the front and side physical pictures of the fully solid-state two-port solar rechargeable device. Sunlight can irradiate the photoanode through the transparent counter electrode and the solid electrolyte.

[0070] Please refer to Figure 3 , the PNMPy on the surface of the photoanode is in a spherical agglomerated distribution with a thickness of about 300 nm.

[0071] Please refer to Figure 4 , the electrochemical window of PPy is more negative than that of PNMPY and is not suitable as the energy storage material for the two-port solar rechargeable device.

[0072] Please refer to Figure 5 , the photocurrent-charge / discharge voltammetric cycling curves of the n-Si / PNMPy photoanode tested in a three-electrode system. Figure 4 It shows that the n-Si / PNMPy photoanode has reversible photocurrent-charge / discharge performance in the window range of 0.25 V - 0.6 V vs RHE.

[0073] Please refer to Figure 6 , WO 3 The voltammetric characteristic curves and open circuit voltage positions of the counter electrode tested in a three-electrode system. Figure 5 It shows that the WO 3 counter electrode can be charged and discharged at a potential of 0.45 V vs RHE under acidic conditions, which can correspond to the potential range of the photoanode's charge and discharge.

[0074] Please refer to Figure 7 , the photocurrent-charge / discharge voltammetric characteristic curves of the all-solid-state solar rechargeable device composed of the n-Si / PNMPy photoanode, solid electrolyte, and WO 3 transparent counter electrode. Figure 6 It shows that in the all-solid-state solar rechargeable device, reversible photocurrent-charge / discharge can occur in the range of the applied bias voltage of -0.2 V - 0.3 V.

[0075] Please refer to Figure 8, the photocurrent-charge and dark-discharge current characteristics curves of a all-solid-state solar rechargeable device composed of an n-Si / PNMPy photoanode, a solid electrolyte, and a WO 3 transparent counter electrode. Figure 7 It shows that the device can cycle photocurrent-charge and dark-discharge under an external bias voltage of 0 V.

[0076] Please refer to Figure 9 and Figure 10 , the photocurrent-charge and dark-discharge long-time current characteristics curves of a all-solid-state solar rechargeable device composed of an n-Si / PNMPy photoanode, a solid electrolyte, and a WO 3 transparent counter electrode and a solar rechargeable device in a liquid system. Figure 9 and Figure 10 It shows that the stability of the all-solid-state device has been greatly improved compared with that of the device in the liquid system.

[0077] Only some exemplary embodiments of the present invention are described above by way of illustration. Undoubtedly, for those of ordinary skill in the art, various different ways can be used to modify the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of the claims of the present invention.

Claims

1. A all-solid-state two-port solar rechargeable device, characterized in that, comprising: A photoanode, the photoanode being an n-type flat silicon polymer composite photoanode, prepared by electrophotodeposition oxidation polymerization method by depositing poly-N-methylpyrrole (PNMPy) on the surface of n-type flat silicon; Quasi-solid electrolyte, formed by gelation of 1 g of PVA, 10 mL of deionized water and 1 g of H 2 SO 4 at 85 °C; Counter electrode, which is transparent tungsten oxide WO 3 Electrode, prepared on an FTO substrate by electrodeposition; Among them, the electrochemical window of the PNMPy has reversible photo-charging and dark-discharging performance within the more positive potential range of 0.25 to 0.6 V vs. RHE of the n-type silicon. The WO 3 The dark-state open-circuit potential of the counter electrode under acidic conditions is 0.45 V vs. RHE, which is matched with the photo-electrode.

2. The all-solid-state two-port solar rechargeable device according to claim 1, characterized in that, the photoanode absorbs light in a back-illumination manner or a front-illumination manner.

3. The all-solid-state two-port solar rechargeable device according to claim 1, characterized in that, the fabrication of the n-type flat silicon polymer composite photoanode includes the following steps: A1. Prepare the electrophotodeposition precursor solution: Dissolve 1M NaCl and 0.1M PNMPy in deionized water as the electrophotodeposition precursor solution; A2. Remove the surface oxide layer of n-Si: Immerse the packaged n-Si in 5% HF solution for 30 s to remove the surface oxide layer; A3. Deposit the PNMPy thin film by three-electrode method: Use n-Si as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode; A4. The precursor solution is used as the electrolyte, with AM1.5G 100mWcm -2 A solar simulator is used as the light source; using the constant voltage test mode of an electrochemical workstation, deposit 200mC / cm 2 at a potential of 0.4V vs Ag / AgCl to obtain an n-type flat silicon polymer composite photoanode.

4. A fully solid-state two-port solar rechargeable device according to claim 1, wherein the counter electrode is transparent tungsten oxide WO 3 counter electrode characterized in that, it includes the following fabrication steps: B1. Clean the FTO: Ultrasonically clean with acetone, ethanol, and deionized water for 30 min respectively, and then dry; B2. Configure the electrodeposition solution: Dissolve 0.08M H 2 O 2 , 0.36M H 2 SO 4 and 0.1M Na 2 WO 4 ·2H 2 O in deionized water as the precursor solution; B3. Use FTO as the working electrode, Ag / AgCl as the reference electrode, a carbon rod as the counter electrode, and the precursor solution described in B2 above as the electrolyte; Using the constant voltage test mode of an electrochemical workstation, deposit 100 mC / cm² at a potential of -0.5 V vs Ag / AgCl 2 , to obtain a WO 3 transparent counter electrode.

5. The all-solid-state two-port solar rechargeable device according to claim 1, characterized in that, Drop the quasi-solid electrolyte on the prepared photoanode, then stick the counter electrode, and leave it for 12 h to obtain the all-solid-state two-port solar rechargeable device.

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