Packaging method and application of optical window of integrated photovoltaic and storage battery

Abstract

The present invention discloses a packaging method and application of an optical window for an integrated photoelectric storage battery. The method comprises the following steps: using a femtosecond laser system to process an optical window in the central area of ​​the battery's positive electrode shell; using anhydrous ethanol to clean the processed positive electrode shell, and then placing the positive electrode shell in plasma for treatment and setting aside; removing the front and back protective films of the flexible substrate and identifying its conductive surface; using a piezoelectric microfluidic injection system to evenly apply epoxy resin slurry around the outer side of the optical window to form an annular adhesive layer; under the guidance of red light, aligning the conductive surface of the flexible substrate with the annular adhesive layer, vacuum adsorption, and pre-curing the annular adhesive layer; using an ultraviolet LED to re-cur the annular adhesive layer to complete the packaging of the optical window for the integrated photoelectric storage battery. The packaging method is applicable to a variety of photoactive positive electrode materials such as V2O5, VO2, and MoS2, and has universal applicability.

Description

Technical Field

[0001] The present invention relates to the field of material science and electrochemical technology, and in particular to a packaging method and application of an optical window of an integrated light-storage battery. Background Art

[0002] With the development of integrated photovoltaic and energy storage technology, the packaging technology of battery optical windows has become a key factor in determining device performance. Traditional photovoltaic energy storage battery holes are mainly opened by mechanical drilling (such as high-speed rotating drill bits), creating holes in the battery positive shell at designated locations for optical window installation. If the hole diameter accuracy is insufficient and the burrs on the hole edges are not treated during the drilling process, it can easily lead to poor seal fit or cause cracks due to stress concentration during subsequent packaging, posing a leakage risk. Traditional optical window packaging usually physically bonds transparent glass or transparent plastic film to the battery shell using 502 glue. During the packaging process, the glue is prone to cracking due to temperature changes due to the difference in thermal expansion coefficients between the optical material and the shell material; if the mechanical seal has dimensional tolerances or is not properly installed, it is difficult to form an effective seal. In the existing technology, there are two core problems with optical window packaging technology.

[0003] The first is insufficient sealing and size adaptation: traditional external packaging methods (such as glue sealing) are prone to electrolyte leakage due to mechanical stress or material aging. Especially in micro devices such as button batteries, the size mismatch between the window and the substrate (such as incomplete coverage or excessive blocking of the substrate) will significantly reduce the light absorption efficiency and affect charge generation and transmission.

[0004] The second is interface contact and universality defects: the contact interface between the optical window and the photoactive material lacks systematic optimization, resulting in uneven electron transmission, and the existing process is only designed for a single battery system, which makes it difficult to adapt to different photoactive materials such as vanadium oxide, manganese oxide and the differentiated needs of lithium / sodium / zinc ion batteries.

[0005] Currently available integrated solar-to-storage battery packaging methods for the positive-side apertures do not specify the geometric matching parameters between the window and substrate, nor do they address the optimization of the sealing structure for internal sealing. Related work has focused on the welding structure of button cell electrode assemblies, but has not addressed the issues of light-transmitting packaging and dimensional design of the optical window. Therefore, a universal packaging method based on precise dimensional matching and internal sealing structures is urgently needed to improve the reliability and performance of integrated solar-to-storage batteries. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of existing technologies and provides a packaging method and application for an optical window in an integrated solar-energy battery. By precisely matching the internal sealing structure and packaging materials, as well as the optical window's light-transmitting properties and dimensions, the present invention addresses the issue of electrolyte leakage during battery packaging, effectively protecting the battery's internal components from full contact with the electrolyte and extending the battery's service life.

[0007] To achieve the above purpose, the technical solution designed by the present invention is as follows:

[0008] The present invention provides a packaging method for an optical window of a photovoltaic integrated battery, comprising the following steps:

[0009] (1) Using a femtosecond laser system to process an optical window in the center area of ​​the battery positive electrode shell;

[0010] (2) Cleaning the cathode shell of step (1) with anhydrous ethanol, and then placing the cathode shell in plasma for treatment and setting aside;

[0011] (3) Remove the front and back protective films of the flexible substrate and identify its conductive surface;

[0012] (4) Using a piezoelectric microfluidic injection system, the epoxy resin slurry is evenly coated around the outer side of the optical window to form an annular adhesive layer;

[0013] (5) Under the guidance of red light, align the conductive surface of the flexible substrate with the annular adhesive layer, vacuum adsorb, and then pre-cure the annular adhesive layer;

[0014] (6) Use ultraviolet LED to re-solidify the annular adhesive layer to complete the packaging of the optical window of the integrated light-storage battery.

[0015] Furthermore, in step (1), the specific parameters of the femtosecond laser system are: wavelength 750-850 nm, pulse width 45-55 fs, and repetition frequency 0.5-1.5 kHz;

[0016] The diameter of the optical window is 5~10 nm, and the edge roughness of the optical window is Ra≤50 nm.

[0017] Furthermore, the specific parameters of the femtosecond laser system are: wavelength 800 nm, pulse width 50 fs, repetition frequency 1 kHz;

[0018] The diameter of the optical window is 8 nm.

[0019] Furthermore, in step (2), the specific steps of cleaning are: first, perform 40 kHz ultrasonic waves for 5 to 6 minutes, and then simultaneously perform 40 kHz ultrasonic waves and 800 kHz megasonic waves for 25 to 30 minutes, with the power of ultrasonic waves and megasonic waves being 50% each;

[0020] The plasma is argon gas, the plasma treatment power is 45-50 W, the gas pressure is 10-12 Pa, and the treatment time is 10-30 min.

[0021] Furthermore, in step (3), the flexible substrate is PET-ITO or PEN-ITO, and the diameter of the flexible substrate is 7-12 mm and the thickness is 0.2-0.5 mm.

[0022] Furthermore, the flexible substrate is PET-ITO, and the diameter of the flexible substrate is 10 mm.

[0023] Furthermore, in step (4), the epoxy resin slurry is a slurry containing 0.5% nano-SiO2 modified epoxy resin;

[0024] The thickness of the annular adhesive layer is 95~105 μm.

[0025] Furthermore, in the step (5), 0 Pa < vacuum adsorption pressure < 10 Pa, the pre-curing temperature is 55-65° C., and the pre-curing time is 4-6 min;

[0026] In step (6), the power of the ultraviolet LED is 6 to 10 W, the wavelength is 365 nm, and the re-curing time is 5 to 30 seconds.

[0027] The present invention also provides a positive electrode shell containing an optical window, wherein the optical window of the positive electrode shell is packaged using the packaging method.

[0028] The present invention also provides a photovoltaic and storage integrated battery, which comprises the positive electrode shell.

[0029] Principle of the present invention:

[0030] 1. This invention uses a femtosecond laser system to fabricate an optical window on the cathode shell. This process achieves non-thermal ablation through a multiphoton absorption mechanism, concentrating energy in the processing area and avoiding material melting and deformation caused by thermal diffusion. Furthermore, through an ultrashort pulse cold working mechanism, a heat-damaged microstructure with an edge roughness of Ra ≤ 50 nm is achieved, ensuring optical distortion at the window edge is less than 5%, meeting the high-precision light transmission requirements for in-situ optical characterization. This invention uses a slurry containing 0.5% nano-SiO2-modified epoxy resin. This nano-SiO2-modified epoxy resin enhances strength by increasing the interfacial anchoring effect. A viscosity of 500 mPa·s ensures uniform adhesive layer spreading. The annular structure provides sealing support, and the nanofiller enhances mechanical properties.

[0031] 2. The present invention uses PET-ITO as a flexible substrate and selects PET-ITO / PEN-ITO materials as the perforated battery shell holes because they have material properties that match the requirements of solar storage batteries (the transmittance of PET and PEN is 88-92% and over 90%, respectively; the square resistance of the ITO coating is as low as below 10 Ω and it is transparent and conductive; the material has flexibility with a bending radius of less than 1 mm at room temperature), process compatibility and stability (resistant to ethanol and argon plasma treatment; the Tg of PET and PEN is 70°C and 100°C, respectively, and can withstand pre-curing temperatures; the ITO coating can be deposited by processes such as magnetron sputtering, and the substrate can be easily processed to a diameter of 7-12 mm to match the optical window size), as well as cost and mass production advantages (as a mature flexible electronic material, it has stable processing and lower costs than materials such as graphene).

[0032] 3. The present invention adopts a diameter difference of 2 mm between the transparent flexible substrate and the optical window. The diameter difference between the transparent flexible substrate and the optical window is designed to be 2 mm to meet the requirements of annular adhesive layer coating and packaging (when the optical window diameter is D, the flexible substrate diameter D+2 mm can make the radial width of the annular adhesive layer reach 1 mm, ensuring that the adhesive layer has sufficient adhesion and the ability to buffer mechanical stress to prevent electrolyte leakage and window rupture), ensure alignment accuracy and optical path integrity (the 2 mm difference provides a fault tolerance margin for red light-guided alignment to avoid incomplete substrate coverage or structural redundancy, and makes the substrate edge extend 1 mm beyond the window edge to ensure optical signal transmission efficiency), and adapt to packaging process parameters (under a vacuum adsorption pressure of 0~10 Pa and a pre-curing temperature of 55~65°C, ensure that the substrate is evenly bonded to the adhesive layer, and at the same time, ensure that the light intensity at the edge of the adhesive layer is uniform and completely cured during UV curing).

[0033] Beneficial effects of the present invention:

[0034] 1. This invention solves the electrolyte leakage problem of conventional battery optical window packaging by optimizing the packaging method of the battery optical window, strictly selecting the packaging substrate material, and controlling the amount of packaging material used. This effectively protects the internal battery components from full contact with the electrolyte, extending the battery life, and significantly improving the convenience of testing and electrochemical performance of integrated photovoltaic and battery storage batteries. This invention opens up the possibility of integrating battery positive electrode materials and other functional materials into a single unit, facilitating the development of multifunctional, integrated photovoltaic and rechargeable button batteries.

[0035] 2. This invention constructs an optimized geometric model for the photoelectric conversion interface by precisely matching the transparent flexible substrate and optical window (diameter difference of 2 mm) and minimizing the amount of epoxy resin used (≤15 μL). This model ensures a light transmittance exceeding 85% while improving battery cycling stability by 40%. Compared to traditional packaging processes, this invention creatively addresses key interface issues in integrated photoelectric storage devices while maintaining testing convenience. It provides a standardized preparation method for in situ spectroelectrochemical studies and establishes an innovative technology system combining precision optical window fabrication, flexible conductive substrate adaptation, and optimized interface packaging.

[0036] 3. The inner sealed V6O assembled by the present invention 13 The integrated photovoltaic and storage battery showed excellent comprehensive performance under illumination: at 1 A g -1 The light-assisted cycle life of more than 1400 times (capacity retention rate>80%) is achieved at a current density of 0.1 A g, which is more than 6 times higher than that of traditional vanadium-based materials. -1 The light-assisted discharge capacity is as high as 468.7 mAh g -1 At the same time, the light conversion efficiency is as high as 3.45%, which is significantly better than similar reported integrated light-storage batteries.

[0037] 4. Choose V6O 13 The base positive electrode serves as the positive electrode for an integrated solar-energy storage battery. The integrated solar-energy storage battery assembled using the packaging method of the present invention exhibits reversible photocharging and cycling performance. The packaging method of the present invention is applicable to a variety of photoactive semiconductor materials, including vanadium oxide and manganese oxide, and possesses universal applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of the integrated photovoltaic and storage battery assembled with an inner sealed structure;

[0039] In the figure, 1 is the optical window, 2 is the PET-ITO flexible substrate, 3 is the open hole positive electrode shell, 4 is the positive electrode, 5 is the separator, 6 is the zinc foil, 7 is the gasket, 8 is the spring, and 9 is the negative electrode shell;

[0040] Figure 2 Schematic diagram of the optical window of the integrated photovoltaic and storage battery;

[0041] In the figure, the area marked by the dotted line is the optical window;

[0042] Figure 3 is a schematic diagram of the optical window size;

[0043] In the figure, R is the radius of the positive electrode shell, r is the radius of the optical window, d is the seal width, and l is the conductive path width (l=Rrd);

[0044] Figure 4The result diagram of the optimal matching size of the optical window and transparent flexible substrate of the integrated photovoltaic battery;

[0045] Figure 5 The integrated solar-storage battery assembled with an inner-sealed structure has a scanning rate of 0.1 mV s -1 Comparison of cyclic voltammetry curves;

[0046] Figure 6 Diagram of the light-assisted capacity of the integrated light-storage battery assembled for the inner-sealed structure;

[0047] Figure 7 The rate performance diagram of the integrated photovoltaic and storage battery assembled with an inner sealed structure;

[0048] Figure 8 The light-assisted cycle performance diagram of the integrated photovoltaic and storage battery assembled with an internally sealed structure and the integrated photovoltaic and storage battery with traditional external packaging. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below with reference to specific embodiments so that those skilled in the art can understand.

[0050] Example 1

[0051] The packaging method of the optical window of the integrated photovoltaic battery includes the following steps:

[0052] 1. Using a femtosecond laser system with a wavelength of 800 nm and a pulse width of 50 fs (repetition rate of 1 kHz), a circular optical window with a diameter of 8 mm was machined in the center area of ​​the positive shell of a CR2032 battery (e.g. Figure 2 The edge roughness of the optical window is Ra≤50 nm.

[0053] 2. Place the cathode casing processed in step 1 in a polytetrafluoroethylene beaker. Add 20 mL of anhydrous ethanol and place the CR2032 cathode casing (optical window facing up) on a polytetrafluoroethylene stand within the beaker (avoiding direct contact with the beaker wall), ensuring the liquid level completely submerges the workpiece. Combined 40 kHz ultrasonic and 800 kHz megasonic cleaning for a total of 30 minutes: First, activate the 40 kHz ultrasonic wave for 5 minutes (80% power) to focus on removing micron-sized metal debris (>5 μm) and large oil clumps remaining from the laser processing. Then, activate the 40 kHz ultrasonic and 800 kHz megasonic waves simultaneously for 25 minutes (50% power each for ultrasonic and megasonic waves). This dual-frequency synergy removes submicron particles (0.1-5 μm) and medium-viscosity oils, utilizing the ethanol's dissolution effect to remove the released contaminants. The cleaned cathode casing is then transferred to a plasma drying oven and treated in a 50 W argon plasma (10 Pa pressure) for 10 minutes.

[0054] 3. Prepare a 10 mm diameter PET-ITO wafer (0.3 mm ≤ thickness ≤ 0.5 mm) as a flexible substrate. Inside an argon glove box, remove the protective films on both sides using a film stripping device. This avoids static contamination introduced by traditional manual operations, effectively reduces particle contamination on the substrate surface, and ensures the conductivity of the ITO layer and the cleanliness of subsequent processes.

[0055] 4. Conductivity mapping was performed on both sides of the PET-ITO flexible substrate using a four-probe method (probe spacing 1 mm) to identify the conductive surface (square resistance of the conductive surface < 20 Ω).

[0056] 5. Using a piezoelectric microfluidic injection system (droplet volume control accuracy ±2%), evenly apply 5 μL of a slurry containing 0.5% nano-SiO2-modified epoxy resin (viscosity 500 mPa•s) around the outside of the optical window to form an annular adhesive layer with a thickness of 100±5 μm (optical transmittance of the adhesive layer >90%, shear strength ≥15 MPa ≥12 MPa).

[0057] 6. Guided by red light projected by a digital micromirror device (DMD) (with a positioning accuracy of ±200 nm), the conductive surface of the PET-ITO flexible substrate and the annular adhesive layer are precisely aligned. The core function of the red light is to provide a visual alignment mark to ensure precise alignment between the flexible substrate and the optical window. DMD technology, with its high-precision patterning, dynamic adjustment capabilities, and automation compatibility, is the ideal red light projection solution for solar cell packaging. Vacuum adsorption (0 Pa < pressure < 10 Pa) eliminates the interfacial gap between the flexible substrate and the positive electrode casing, and the annular adhesive layer is pre-cured (60°C, 5 minutes) to achieve initial mechanical fixation. High-precision alignment ensures electrical connection and optical coaxiality. Vacuum bonding eliminates air bubbles, and pre-curing prevents displacement.

[0058] 7. Use 6 W UV-LED (main peak 365 nm) for re-curing for 5 seconds to induce rapid cross-linking of the surface resin; use dielectric loss to achieve internal deep curing, so that the shear strength of the packaging interface between the flexible substrate and the optical window is increased to more than 8 MPa, completing the packaging of the optical window of the integrated solar-storage battery.

[0059] Example 2

[0060] The preparation method of the integrated photovoltaic and energy storage battery specifically comprises the following steps:

[0061] 1. Use the packaging method of Example 1 to package the optical window of the perforated positive electrode shell to obtain a perforated positive electrode shell containing an optical window, and combine Figure 1 As shown in the figure, the positive electrode, separator, zinc foil, gasket, spring and negative electrode shell are stacked in sequence on the open positive electrode shell with an optical window, and the electrolyte is added to assemble the integrated photovoltaic battery.13 As the positive electrode material, the positive electrode material was drop-coated on a 17 mm 100 mesh titanium mesh, zinc foil was selected as the negative electrode, and zinc trifluoromethanesulfonate was used as the electrolyte.

[0062] 2. After the battery is assembled, it is placed on a small hydraulic button battery sealing machine with the positive electrode shell facing downward. The pressure during battery sealing is 50 MPa, and double closed-loop control is used to achieve high airtightness (leakage rate < 5×10 -10 mbar•L / s), and a photovoltaic and storage integrated battery was obtained.

[0063] Traditional solar cell optical window packaging typically involves gluing transparent optical glass (or transparent plastic) to the battery housing or securing it with a mechanical seal. During the packaging process, the glue can easily crack due to differences in thermal expansion coefficients between the optical and housing materials. Mechanical seals with dimensional tolerances or improper installation can make it difficult to form an effective seal, and there can be significant variations in installation position accuracy. Results are as follows: Figure 8 As shown, the method of welding external packaging has a serious risk of leakage, which seriously affects the stability of the photovoltaic cell cycle test. The precise internal packaging of the present invention significantly improves the cycle stability and battery capacity of the photovoltaic cell.

[0064] The internally sealed optical window effectively prevents electrolyte leakage during battery packaging. When pressure is applied to the package, the transparent PET-ITO flexible substrate maintains closer contact with the optical window, effectively protecting the battery's internal components from full contact with the electrolyte and extending battery life. The conductive surface of the transparent PET-ITO flexible substrate faces the optical window, promoting even current distribution across the surface of the perforated positive electrode shell during battery charging and discharging.

[0065] Example 3

[0066] Performance test of the integrated photovoltaic and energy storage battery of Example 2

[0067] 1. Analyze the optimal matching size of the optical window and transparent flexible substrate of the integrated photovoltaic cell. The results are as follows: Figure 4 As shown, combined Figure 3It can be seen that the optical window, transparent flexible substrate, and epoxy resin dosage of integrated solar-energy storage batteries must be sized appropriately for each battery model to achieve high-performance integrated solar-energy storage batteries. r determines the battery's charging efficiency, d determines its sealing and cycle life, and l determines its internal conductivity. In integrated solar-energy storage batteries, based on the positive electrode shell radius R, the optical window radius r, sealing width d, and conductive path width l (l = Rrd) must be adjusted accordingly. A larger r increases the solar charging efficiency (due to a larger light transmission area), but compresses d (affecting sealing and cycle life; a smaller d can lead to electrolyte leakage and reduced lifespan) and l (a smaller l increases internal resistance and poor conductivity). The three parameters must satisfy R > r + d. Small batteries balance efficiency and sealing. High-power batteries prioritize maintaining l and reducing internal resistance, while long-life batteries prioritize increasing d to strengthen sealing and achieve optimal performance.

[0068] 2. The scanning rate of the integrated photoelectric storage battery is 0.1 mV s -1 Cyclic voltammetry analysis was performed, and the results were as follows: Figure 5 As shown, the area of ​​the cyclic voltammetry curve of the internally assembled integrated photo-storage battery under light is significantly higher than that in the dark state, indicating that light can effectively improve the battery capacity.

[0069] 3. Perform light-assisted capacity analysis on the integrated photovoltaic and storage battery. The results are as follows: Figure 6 As shown, the integrated photovoltaic battery has a -1 At the current density, the light-assisted discharge capacity is as high as 468.7 mAh g -1 Compared with the conventional discharge of zinc-ion batteries, the capacity improvement rate is close to 20%, which is a relatively high level among batteries of the same type.

[0070] 4. The rate performance of the integrated solar-storage battery under light-assisted charging and conventional charging is analyzed. The results are as follows: Figure 7 As shown in the figure, the light-assisted charging capacity is significantly higher than the conventional charging capacity, and the battery stability is good in both charging modes.

[0071] 5. Analyze the light-assisted cycle performance of the integrated light-storage battery. The results are as follows: Figure 8 As shown, at 1 A g -1 V6O assembled in an internal seal under current density 13 The integrated battery with light-storage function (precise internal packaging) achieves high capacity (340~380 mAh g) compared to conventional charging mode. -1 ), which not only significantly improves the battery capacity, but also achieves a light-assisted cycle life of over 1,400 times (capacity retention rate > 90%).

[0072] Example 4

[0073] The packaging method of the optical window of the integrated photovoltaic battery includes the following steps:

[0074] 1. Using a femtosecond laser system with a wavelength of 800 nm and a pulse width of 50 fs (repetition rate of 1 kHz), a 5 mm diameter circular optical window (such as Figure 2 The edge roughness of the optical window is Ra≤50 nm.

[0075] 2. Place the cathode shell processed in step 1 in a polytetrafluoroethylene beaker, add 15 mL of anhydrous ethanol, and clean it according to the method in step 2 of Example 1. Then transfer it to a plasma drying oven and treat it in 50 W argon plasma (pressure 10 Pa) for 30 min.

[0076] 3. Prepare a 7 mm diameter PET-ITO flexible substrate disc (0.3 mm ≤ thickness ≤ 0.5 mm). In an argon glove box, remove the front and back protective films using a film stripping device to avoid static contamination introduced by traditional manual operations.

[0077] 4. Conductivity mapping of both sides of the PET-ITO flexible substrate was performed using a four-probe method (probe spacing 1 mm) to identify the conductive surface.

[0078] 5. Using a piezoelectric microfluidic injection system (droplet volume control accuracy ±2%), evenly apply 5 μL of a 0.5% nano-SiO2-modified epoxy resin slurry (viscosity 500 mPa•s) around the outside of the optical window to form an annular adhesive layer with a thickness of 100 ± 5 μm (optical transmittance > 90%, shear strength ≥ 15 MPa, ≥ 12 MPa).

[0079] 6. Under the guidance of red light projected by a digital micromirror device (DMD) (positioning accuracy ±200 nm), the conductive surface of the PET-ITO flexible substrate and the annular adhesive layer were precisely aligned. The interfacial gap between the flexible substrate and the positive electrode shell was eliminated through vacuum adsorption (0 Pa < pressure < 10 Pa), and the annular adhesive layer was pre-cured (60°C, 10 min) to achieve initial mechanical fixation.

[0080] 7. Use 6 W UV-LED (main peak 365 nm) for re-curing for 10 seconds to induce rapid cross-linking of the surface resin; use dielectric loss to achieve internal deep curing, so that the shear strength of the packaging interface between the flexible substrate and the optical window is increased to more than 8 MPa, completing the packaging of the optical window of the integrated solar-storage battery.

[0081] Example 5

[0082] The preparation method of the integrated photovoltaic and energy storage battery specifically comprises the following steps:

[0083] 1. Use the packaging method of Example 4 to package the optical window of the perforated positive electrode shell to obtain a perforated positive electrode shell containing an optical window, and combine Figure 1 As shown in the figure, the positive electrode, separator, zinc foil, gasket, spring and negative electrode shell are stacked in sequence on the open positive electrode shell with an optical window, and the electrolyte is added to assemble the integrated photovoltaic battery. 13 As the positive electrode material, the positive electrode material was drop-coated on a 17 mm 100 mesh titanium mesh, zinc foil was selected as the negative electrode, and zinc trifluoromethanesulfonate was used as the electrolyte.

[0084] 2. After the battery is assembled, it is placed on a small hydraulic button battery sealing machine with the positive electrode shell facing downward. The pressure during battery sealing is 45 MPa, and double closed-loop control is used to achieve high airtightness (leakage rate < 5×10 -10 mbar•L / s), and a photovoltaic and storage integrated battery was obtained.

[0085] Taking the solar-storage integrated battery assembled in this embodiment as an example, by placing the conductive surface of the transparent PET-ITO flexible substrate toward the optical window and adjusting the size of r, the sealing performance of the interface between the positive electrode material and the open-hole positive electrode shell is improved, and the conductivity of the electrode material is enhanced. The solar-storage integrated battery assembled with the internal sealing structure has a high conductivity at 70 mW / cm 2 Under light intensity of 100 nm, reversible light-assisted charge and discharge cycles were achieved, with a reversible capacity of 330~340 mAh / g.

[0086] Example 6

[0087] The packaging method of the optical window of the integrated photovoltaic battery includes the following steps:

[0088] 1. Using a femtosecond laser system with a wavelength of 800 nm and a pulse width of 50 fs (repetition rate of 1 kHz), a circular optical window with a diameter of 10 mm was machined in the center area of ​​the positive electrode shell of a CR2016 battery (e.g. Figure 2 The edge roughness of the optical window is Ra≤50 nm.

[0089] 2. Place the cathode shell processed in step 1 in a polytetrafluoroethylene beaker, add 10 mL of anhydrous ethanol, and clean it according to the method in step 2 of Example 1. Then transfer it to a plasma drying oven and treat it in 50 W argon plasma (pressure 10 Pa) for 30 min.

[0090] 3. Prepare a 12 mm diameter PET-ITO flexible substrate disc (0.2 mm ≤ thickness ≤ 0.5 mm). Remove the front and back protective films using a film stripping device within an argon glove box to avoid static contamination introduced by traditional manual operations.

[0091] 4. Conductivity mapping of both sides of the PET-ITO flexible substrate was performed using a four-probe method (probe spacing 1 mm) to identify the conductive surface (square resistance < 20 Ω);

[0092] 5. Using a piezoelectric microfluidic injection system (droplet volume control accuracy ±2%), evenly apply 15 μL of a 0.5% nano-SiO2-modified epoxy resin slurry (viscosity 500 mPa•s) around the outside of the optical window to form an annular adhesive layer with a thickness of 100±5 μm (optical transmittance of the adhesive layer >90%, shear strength ≥15 MPa ≥12 MPa).

[0093] 6. Under the guidance of red light projected by a digital micromirror device (DMD) (positioning accuracy ±200 nm), the conductive surface of the PET-ITO flexible substrate and the annular adhesive layer area were precisely aligned. The interfacial gap between the flexible substrate and the positive electrode shell was eliminated through vacuum adsorption (0 Pa < pressure < 10 Pa), and the annular adhesive layer was pre-cured (60°C, 10 min) to achieve initial mechanical fixation.

[0094] 7. Use 6 W UV-LED (main peak 365 nm) for re-curing for 20 seconds to induce rapid cross-linking of the surface resin; use dielectric loss to achieve internal deep curing, so that the shear strength of the packaging interface between the flexible substrate and the optical window is increased to more than 8 MPa, completing the packaging of the optical window of the integrated solar-storage battery.

[0095] Example 7

[0096] The preparation method of the integrated photovoltaic and energy storage battery specifically comprises the following steps:

[0097] 1. Use the packaging method of Example 6 to package the optical window of the perforated positive electrode shell to obtain a perforated positive electrode shell containing an optical window, and combine Figure 1 As shown in the figure, the positive electrode, separator, zinc foil, gasket, spring and negative electrode shell are stacked in sequence on the open positive electrode shell with an optical window, and the electrolyte is added to assemble the integrated photovoltaic battery. 13 As the positive electrode material, the positive electrode material was drop-coated on a 12 mm PET-ITO flexible substrate, zinc foil was selected as the negative electrode, and zinc trifluoromethanesulfonate was used as the electrolyte.

[0098] 2. After the battery is assembled, it is placed on a small hydraulic button battery sealing machine with the positive electrode shell facing downward. The pressure during battery sealing is 55 MPa, and double closed-loop control is used to achieve high airtightness (leakage rate < 5×10 -10 mbar•L / s), and a photovoltaic and storage integrated battery was obtained.

[0099] Taking the internally sealed and assembled integrated photovoltaic cell obtained in this embodiment as an example, the positive electrode material is directly drop-coated on a transparent PET-ITO flexible substrate, eliminating the need to use a titanium mesh as a current collector, thereby reducing the cost of battery assembly. By increasing the size of the perforated positive electrode shell r and optimizing the size d, the sealing of the battery is significantly improved, but the conductivity inside the battery is reduced. The internally sealed and assembled integrated photovoltaic cell has a power output of 70 mW / cm 2 Under light intensity of 200 nm, reversible light-assisted charge and discharge cycles were achieved, with a reversible capacity of 280~300 mAh / g.

[0100] Example 8

[0101] The packaging method of the optical window of the integrated photovoltaic battery includes the following steps:

[0102] 1. A femtosecond laser system with a wavelength of 750 nm and a pulse width of 45 fs (repetition rate of 0.5 kHz) was used to process a 10 mm diameter circular optical window in the center of the positive electrode shell of a CR2016 battery (e.g. Figure 2 The edge roughness of the optical window is Ra≤50 nm.

[0103] 2. Place the cathode shell processed in step 1 in a polytetrafluoroethylene beaker, add 10 mL of anhydrous ethanol, and clean it according to the method in step 2 of Example 1. Then transfer it to a plasma drying oven and treat it in 45 W argon plasma (pressure 12 Pa) for 30 min.

[0104] 3. Prepare a 12 mm diameter PEN-ITO flexible substrate wafer (0.2 mm ≤ thickness ≤ 0.5 mm). Remove the front and back protective films using a film stripping device within an argon glove box to avoid static contamination introduced by traditional manual operations.

[0105] 4. Conductivity mapping of both sides of the PEN-ITO flexible substrate was performed using a four-probe method (probe spacing 1 mm) to identify the conductive surface (sheet resistance < 20 Ω).

[0106] 5. Using a piezoelectric microfluidic injection system (droplet volume control accuracy ±2%), evenly apply 15 μL of a 0.5% nano-SiO2-modified epoxy resin slurry (viscosity 500 mPa•s) around the outside of the optical window to form an annular adhesive layer with a thickness of 100±5 μm (optical transmittance of the adhesive layer >90%, shear strength ≥15 MPa ≥12 MPa).

[0107] 6. Under the guidance of red light projected by a digital micromirror device (DMD) (positioning accuracy ±200 nm), the conductive surface of the PEN-ITO flexible substrate and the annular adhesive layer area were precisely aligned. The interfacial gap between the flexible substrate and the positive electrode shell was eliminated by vacuum adsorption (0 Pa < pressure < 10 Pa), and the annular adhesive layer was pre-cured (55°C, 10 min) to achieve initial mechanical fixation.

[0108] 7. Use 10 W UV-LED (main peak 365 nm) for re-curing for 30 seconds to induce rapid cross-linking of the surface resin; use dielectric loss to achieve internal deep curing, so that the shear strength of the packaging interface between the flexible substrate and the optical window is increased to more than 8 MPa, completing the packaging of the optical window of the integrated solar-storage battery.

[0109] Example 9

[0110] The packaging method of the optical window of the integrated photovoltaic battery includes the following steps:

[0111] 1. Using a femtosecond laser system with a wavelength of 850 nm and a pulse width of 55 fs (repetition rate of 1.5 kHz), a circular optical window with a diameter of 10 mm was machined in the center area of ​​the positive electrode shell of a CR2016 battery (e.g. Figure 2 The edge roughness of the optical window is Ra≤50 nm.

[0112] 2. Place the cathode shell processed in step 1 in a polytetrafluoroethylene beaker, add 10 mL of anhydrous ethanol, and clean it according to the method in step 2 of Example 1. Then transfer it to a plasma drying oven and treat it in 50 W argon plasma (pressure 10 Pa) for 30 min.

[0113] 3. Prepare a 12 mm diameter PEN-ITO flexible substrate wafer (0.2 mm ≤ thickness ≤ 0.5 mm). Remove the front and back protective films using a film stripping device within an argon glove box to avoid static contamination introduced by traditional manual operations.

[0114] 4. Conductivity mapping of both sides of the PEN-ITO flexible substrate was performed using a four-probe method (probe spacing 1 mm) to identify the conductive surface (sheet resistance < 20 Ω).

[0115] 5. Using a piezoelectric microfluidic injection system (droplet volume control accuracy ±2%), evenly apply 15 μL of a 0.5% nano-SiO2-modified epoxy resin slurry (viscosity 500 mPa•s) around the outside of the optical window to form an annular adhesive layer with a thickness of 100±5 μm (optical transmittance of the adhesive layer >90%, shear strength ≥15 MPa ≥12 MPa).

[0116] 6. Under the guidance of red light projected by a digital micromirror device (DMD) (positioning accuracy ±200 nm), the conductive surface of the PEN-ITO flexible substrate and the annular adhesive layer area were precisely aligned. The interfacial gap between the flexible substrate and the positive electrode shell was eliminated through vacuum adsorption (0 Pa < pressure < 10 Pa), and the annular adhesive layer was pre-cured (65°C, 10 min) to achieve initial mechanical fixation.

[0117] 7. Use 10 W UV-LED (main peak 365 nm) for re-curing for 30 seconds to induce rapid cross-linking of the surface resin; use dielectric loss to achieve internal deep curing, so that the shear strength of the packaging interface between the flexible substrate and the optical window is increased to more than 8 MPa, completing the packaging of the optical window of the integrated solar-storage battery.

[0118] Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on this embodiment without inventiveness, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A packaging method for an optical window of a photovoltaic and energy storage integrated battery, characterized by: The following steps are involved: (1) Using a femtosecond laser system to process an optical window in the center area of ​​the battery positive electrode shell; (2) Cleaning the cathode shell of step (1) with anhydrous ethanol, placing the cathode shell in plasma for drying after cleaning, and setting aside; (3) Remove the front and back protective films of the flexible substrate and identify its conductive surface; The flexible substrate is PET-ITO or PEN-ITO; (4) Using a piezoelectric microfluidic injection system, the epoxy resin slurry is evenly coated on the inside of the positive electrode shell around the outside of the optical window to form an annular adhesive layer; the epoxy resin slurry is a slurry containing 0.5% nano-SiO2 modified epoxy resin; (5) Under the guidance of red light, align the conductive surface of the flexible substrate with the annular adhesive layer, vacuum adsorb, and then pre-cure the annular adhesive layer; (6) Use ultraviolet LED to re-solidify the annular adhesive layer to complete the packaging of the optical window of the integrated light-storage battery.

2. The packaging method according to claim 1, wherein: In step (1), the specific parameters of the femtosecond laser system are: wavelength 750-850 nm, pulse width 45-55 fs, and repetition frequency 0.5-1.5 kHz; The diameter of the optical window is 5~10 nm, and the edge roughness of the optical window is Ra≤50 nm.

3. The packaging method according to claim 2, wherein: The specific parameters of the femtosecond laser system are: wavelength 800 nm, pulse width 50 fs, and repetition frequency 1 kHz; The diameter of the optical window is 8 nm.

4. The packaging method according to claim 1, wherein: In step (2), the specific steps of cleaning are: first, perform 40 kHz ultrasonic waves for 5 to 6 minutes, and then perform 40 kHz ultrasonic waves and 800 kHz megasonic waves simultaneously for 25 to 30 minutes, with the power of ultrasonic waves and megasonic waves being 50% each; The plasma is argon gas, the plasma treatment power is 45-50 W, the gas pressure is 10-12 Pa, and the treatment time is 10-30 min.

5. The packaging method according to claim 1, wherein: In the step (3), the diameter of the flexible substrate is 7-12 mm and the thickness is 0.2-0.5 mm.

6. The packaging method according to claim 5, wherein: The flexible substrate is PET-ITO, and the diameter of the flexible substrate is 10 mm.

7. The packaging method according to claim 1, wherein: In the step (4), the thickness of the annular adhesive layer is 95-105 μm.

8. The packaging method according to claim 1, wherein: In the step (5), 0 Pa < vacuum adsorption pressure < 10 Pa, the pre-curing temperature is 55-65°C, and the pre-curing time is 5-10 min; In step (6), the power of the ultraviolet LED is 6 to 10 W, the wavelength is 365 nm, and the re-curing time is 5 to 30 s.

9. A positive electrode shell containing an optical window, characterized in that: The optical window of the positive electrode shell is encapsulated using the encapsulation method according to claim 1.

10. A photovoltaic and energy storage integrated battery, characterized by: The integrated photovoltaic and energy storage battery comprises the positive electrode shell according to claim 9.

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