Flexible gallium arsenide battery assembly for low-orbit satellite and packaging method of flexible gallium arsenide battery assembly

Abstract

The invention relates to the technical field of space power sources, in particular to a flexible gallium arsenide battery assembly for a low-orbit satellite and a packaging method of the flexible gallium arsenide battery assembly. A first layer of modified polyimide film; a transparent antistatic coating; a flexible gallium arsenide cell chip array; a second layer of modified polyimide film; a flexible metal substrate; wherein all the layers are pressed into a whole through an adhesive; the modified polyimide film is a polyimide film of which the surface is modified by silicon oxide or aluminum oxide; and integrated packaging is realized through the low-outgassing-rate adhesive, so that the long-term interface stability and the use reliability of the battery assembly in compound severe environments such as atomic oxygen, ultraviolet, plasma and high and low temperature circulation are remarkably improved while the structural flexibility and the light weight are ensured.

Description

Technical Field

[0001] This invention relates to the field of space power technology, and more particularly to flexible gallium arsenide battery modules for low-Earth orbit satellites and their packaging methods. Background Technology

[0002] With the rapid development of low-Earth orbit satellite constellations, there is an urgent need for lightweight, high-power, and flexibly attachable satellite power systems. Traditional rigid solar panels are bulky, heavy, and costly to launch, making them unsuitable for large-scale constellation deployments. Therefore, flexible solar cell technology has become a research hotspot.

[0003] However, the extremely harsh environment of low Earth orbit poses the following challenges to flexible battery modules:

[0004] Atomic oxygen erosion: The low-Earth orbit environment is rich in highly reactive atomic oxygen, which can cause severe erosion and degradation of most organic polymer materials (such as conventional polyimide).

[0005] Ultraviolet radiation: Strong ultraviolet radiation can cause adhesives and polymers to age, yellow, and deteriorate in performance.

[0006] High and low temperature cycling: When the satellite enters and exits the shadow area, it experiences a drastic temperature change from -100℃ to +100℃. The mismatch in the thermal expansion coefficients between different materials can lead to interfacial stress, causing delamination and cracking.

[0007] Electrostatic discharge: The space plasma environment can easily cause static electricity to accumulate on the surface of the components, which may trigger electrostatic discharge and damage the battery circuit.

[0008] Vacuum venting: Organic materials release volatile substances in a vacuum environment, which may condense on the satellite's optical lens or sensitive surfaces, causing pollution.

[0009] Existing flexible battery packaging technologies mostly employ single-layer modified polyimide film encapsulation, which lacks sufficient resistance to atomic oxygen and ultraviolet radiation, and also lacks effective electrostatic protection measures, making it difficult to operate stably for extended periods in low-Earth orbit environments. Therefore, developing a novel flexible battery packaging technology that can comprehensively address these challenges is crucial.

[0010] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0011] This invention provides a flexible gallium arsenide battery assembly for low-Earth orbit satellites and its packaging method, which can effectively solve the problems in the background art.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] A flexible gallium arsenide battery module for low-Earth orbit satellites, from top to bottom:

[0014] Flexible glass cover;

[0015] The first layer of modified polyimide film;

[0016] Transparent antistatic coating;

[0017] Flexible gallium arsenide battery chip array;

[0018] The second layer is a modified polyimide film;

[0019] Flexible metal substrate;

[0020] The layers are pressed together using adhesive;

[0021] The modified polyimide film is a polyimide film whose surface has been modified with silicon oxide or aluminum oxide.

[0022] The modified polyimide film of this invention has a surface modified with silicon oxide or aluminum oxide. The ceramic coating generated by silicon oxide or aluminum oxide can effectively block the physical penetration and chemical corrosion of highly reactive atomic oxygen. When atomic oxygen impacts the surface of silicon oxide or aluminum oxide, it is recombinated or scattered, and cannot directly attack the internal adhesive and battery chip, thereby significantly delaying the material's quality loss and performance degradation. The flexible glass cover provides UV protection and physical protection. The transparent antistatic coating can dissipate charge in time and prevent electrostatic discharge from damaging the circuit. The flexible metal substrate alleviates the thermal stress caused by high and low temperature cycling and improves heat dissipation by matching the coefficient of thermal expansion and enhancing thermal conductivity. The layers are pressed together by adhesive to form a stable, lightweight and flexible composite system, thereby significantly improving the reliability and service life of the battery module in multiple harsh environments on low orbits.

[0023] Furthermore, the modification method of the polyimide film includes:

[0024] Q1 uses tetraethyl orthosilicate or aluminum isopropoxide as a precursor to prepare a sol, and forms a wet film with a thickness of 50~200nm on the surface of a polyimide film by slit coating. This step constructs an ultrathin inorganic-organic hybrid transition layer on the surface of the polyimide film through the sol-gel method. The precursor in the wet film can partially penetrate and bond to the surface of the polyimide film, forming chemical bridges such as Si-OC bonds, which significantly enhances the interfacial adhesion between the subsequent ceramic coating and the flexible substrate, and provides a uniform reaction basis for subsequent plasma treatment.

[0025] Q2 involves feeding a polyimide film coated with a wet film into a plasma chamber and bombarding it with plasma in an inert gas atmosphere. Plasma bombardment activates and pre-densifies the film surface in the inert gas atmosphere. High-energy particle bombardment removes surface contaminants, etches and activates polyimide molecular chains, generating a large number of free radicals and active sites. At the same time, it rapidly dehydrates and pre-crosslinks the sol layer, forming a denser transition layer structure, which lays a key foundation for the surface energy and microstructure of the subsequent gradient coating.

[0026] Q3. Under the condition of continuous plasma, a reaction gas is gradually introduced to obtain a modified polyimide film. The reaction gas is hexamethyldisiloxane and oxygen or trimethylaluminum and oxygen. This step uses plasma-assisted chemical vapor deposition (PACVD) to achieve the controllable growth of a gradient ceramic coating on the activated surface. By dynamically adjusting the ratio of the reaction gas and the plasma parameters, the compositional gradient is achieved from a flexible inner layer rich in organic components to a dense inorganic ceramic outer layer, ultimately forming a composite protective layer with excellent atomic oxygen barrier properties, crack resistance and substrate flexibility.

[0027] The surface of the polyimide film is modified with silicon oxide or aluminum oxide, which provides strong interfacial bonding. Through chemical bonding and physical interlocking, it prevents the ceramic coating from peeling off under high and low temperature cycling or bending stress. Secondly, it provides excellent atomic oxygen protection. The dense outer ceramic layer can effectively block and recombine atomic oxygen, while the internal gradient transition layer can dissipate impact energy and prevent microcracks. Finally, it can also maintain the flexibility of the substrate. Compared with a single thick and hard ceramic layer, the gradient design allows the coating to undergo micro-deformation without cracking when the film is bent.

[0028] Furthermore, the thickness of the polyimide film is 10~25μm.

[0029] The aforementioned thickness range ensures that the modified polyimide film possesses sufficient mechanical strength and integrity to effectively block long-term erosion by atomic oxygen and resist minor impacts in the space environment. It also avoids reduced flexibility, thermal stress concentration, or additional weight caused by excessive thickness, thereby improving the long-term structural stability and reliability of the component in the harsh environment of low orbit while maintaining its overall thinness and flexibility.

[0030] Furthermore, the flexible glass cover has a thickness of 30~100μm, and its space-facing side is coated with an anti-reflective film and an anti-radiation film.

[0031] The aforementioned thickness range ensures that the flexible glass cover has sufficient mechanical strength to withstand impacts from micrometeoroids and space debris, while maintaining the necessary flexibility of the material itself, allowing it to conform to the uneven surface of the satellite without easily cracking; the anti-reflection coating on the surface can significantly reduce the loss of sunlight reflection and improve the battery's efficiency in capturing incident photons, while the anti-radiation film can effectively filter high-energy radiation in the ultraviolet band and slow down the photoaging process of the underlying organic materials;

[0032] When microcracks appear in the flexible glass cover due to accidents such as micrometeoroids, the second layer of modified polyimide film can continue to effectively block the intrusion of atomic oxygen and prevent single-point failure. The combination of the two forms a dual protection that combines active and passive protection and complements rigidity and flexibility.

[0033] Furthermore, the transparent antistatic coating (ITO) is a transparent conductive coating of indium tin oxide (ITO) or fluorine-doped tin oxide (ITO), with a sheet resistance ranging from 10 Ω·cm. 3 ~10 6 Ω / □.

[0034] The coating of the aforementioned materials has excellent light transmittance, which can minimize the obstruction of incident sunlight and ensure the power generation efficiency of the battery; using 10 3 ~10 6 The sheet resistance of Ω / □ can provide a controllable and stable discharge channel for the static charge accumulated on the surface without creating a short circuit risk, effectively suppressing the damage of electrostatic discharge to the battery chip;

[0035] Furthermore, the ITO is sandwiched between the first layer of modified polyimide film and the flexible gallium arsenide battery chip array, allowing electrostatic charges to be uniformly discharged to the ITO layer through the upper modified polyimide film. Then, through a pre-designed conductive channel isolated from the battery interconnection strip, the charges are guided to the main structure of the satellite. This avoids the risk of unclear discharge paths or potential interference with the battery circuitry associated with traditional surface coatings.

[0036] Furthermore, the individual battery chips in the flexible gallium arsenide battery chip array are electrically connected by flexible interconnect strips, which are made of copper-clad polyimide substrate.

[0037] The copper-clad polyimide substrate combines the excellent flexibility and high and low temperature resistance of polyimide with the high conductivity of copper foil. It can not only adapt to the overall bending deformation of the component without breaking, but also reduce electrical transmission loss. The battery chips are electrically connected by flexible interconnect strips, which effectively alleviates the connection stress caused by the difference in thermal expansion of materials during severe temperature cycling.

[0038] Furthermore, the method for preparing the adhesive is as follows:

[0039] The product is prepared by mixing 100 parts of a silicone resin prepolymer with a phenyl content of 25-35% as the base polymer with 5-15 parts of hollow ceramic microspheres with a particle size of 100-500 nm, 1-3 parts of a silane coupling agent, 0.001-0.01 parts of a platinum catalyst and 0.0005-0.02 parts of an inhibitor.

[0040] Preferably, the hollow ceramic microspheres are SiO2 or Al2O3, which can act as microsprings. When the adhesive layer expands due to heat or the structure bends, the elastic deformation of the microspheres further reduces the effective modulus of the adhesive and improves the stress dissipation capacity.

[0041] Silane coupling agents have a functional group at one end of their molecules that can form chemical bonds with polyimide, glass, and metal surfaces, and the other end is compatible with organosilicon resins. This enhances the chemical bonding strength between the adhesive and the interfaces of various materials at the molecular level, far exceeding that of simple physical adsorption.

[0042] By adding platinum catalysts and inhibitors, controllable curing is achieved within a temperature window of 120~180℃, ensuring sufficient working time and adequate curing degree in the vacuum autoclave process.

[0043] By introducing nanoscale hollow ceramic microspheres into the phenyl silicone resin system as elastic deformation units and optimizing the phenyl content, the adhesive is synergistically endowed with an elastic modulus below 10 MPa and an elongation at break above 200%, making it an excellent stress buffer medium that can effectively match and absorb the deformation differences of each layer of material during temperature cycling. Through the targeted interfacial chemical bonding design of silane coupling agents, the adhesive strength to materials such as polyimide and glass is significantly enhanced, overcoming the problem of weak interfacial adhesion of such materials. The addition of nano-ceramic microspheres ensures that the adhesive meets the strict gas emission indicators of total mass loss <1.0% and condensable volatiles <0.1% under vacuum conditions, while achieving a synergistic improvement in the mechanical properties of the adhesive layer and its adaptability to the space environment.

[0044] Furthermore, the flexible metal substrate is a titanium foil or molybdenum foil with a thickness of 50~150μm.

[0045] The aforementioned thickness range provides the flexible metal substrate with sufficient mechanical strength to support the entire battery array without easily deforming, while maintaining the overall lightweight and bendable characteristics of the structure; titanium foil has excellent specific strength and corrosion resistance, while molybdenum foil has a thermal expansion coefficient that is more compatible with gallium arsenide chips, which can significantly reduce interfacial stress during thermal cycling and prevent delamination and cracking; the good thermal conductivity of both facilitates the rapid lateral diffusion of battery operating heat, avoiding local overheating that could affect performance and lifespan;

[0046] The coefficient of thermal expansion (CTE) of the flexible metal substrate made of titanium foil or molybdenum foil is precisely matched with that of the flexible gallium arsenide battery chip. For example, the CTE of molybdenum is very close to that of GaAs. The second layer of modified polyimide film acts as a stress buffer layer. Its own flexibility and good adhesion to the metal substrate obtained through modification can absorb and redistribute the small deformations transferred from the metal substrate, effectively preventing thermal stress from being directly transferred to the brittle battery chip interconnects. This greatly reduces the risk of interconnect breakage or chip cracking due to CTE mismatch.

[0047] The packaging method for the flexible gallium arsenide battery assembly for low-Earth orbit satellites of the present invention includes:

[0048] In a clean environment, S1 attaches the second layer of modified polyimide film to a flexible metal substrate using an adhesive to form a bottom composite structure.

[0049] S2 fixes the flexible gallium arsenide battery chip array to the underlying composite structure using adhesive.

[0050] S3 prepares a transparent antistatic coating on the surface of the battery chip array and the underlying composite structure;

[0051] S4 involves covering the first layer of modified polyimide film onto the transparent antistatic coating using an adhesive, forming an intermediate composite structure;

[0052] S5 presses the flexible glass cover onto the top layer of the intermediate composite structure using an adhesive.

[0053] S6 places the overall structure obtained in S5 into a vacuum autoclave for curing, thus completing the encapsulation.

[0054] The encapsulation method of this invention constructs each layer from a flexible metal substrate upwards, and operates in a clean environment, ensuring precise alignment and interface cleanliness of each functional layer; the sequential integration step allows the transparent antistatic coating to completely cover the battery array, while the superposition of the double-layer modified polyimide film and the flexible glass cover forms a progressive protection system; finally, curing is carried out in a vacuum autoclave, and the interlayer gas is completely eliminated under the combined effect of temperature and pressure, promoting uniform cross-linking of the adhesive and achieving a dense and integrated structure.

[0055] Furthermore, the curing parameters are: curing temperature of 120~180℃, pressure of 0.3~0.8MPa, and curing time of 1~3h.

[0056] The aforementioned pressure and temperature compress the layers into a dense, defect-free whole, eliminating tiny delaminations or bubbles that could become the starting point of failure in orbit.

[0057] The technical solution of this invention achieves the following technical effects: The surface of the modified polyimide film of this invention is modified with silicon oxide or aluminum oxide. The ceramic coating generated by silicon oxide or aluminum oxide can effectively block the physical penetration and chemical corrosion of highly active atomic oxygen. When atomic oxygen impacts the surface of silicon oxide or aluminum oxide, it is recombinated or scattered, and cannot directly attack the internal adhesive and battery chip, thereby significantly delaying the material's quality loss and performance degradation; the flexible glass cover provides UV resistance and physical protection; the transparent antistatic coating can dissipate charge in time and prevent electrostatic discharge from damaging the circuit; the flexible metal substrate alleviates the thermal stress caused by high and low temperature cycles and improves heat dissipation by matching the coefficient of thermal expansion and enhancing thermal conductivity; the layers are pressed into a whole by adhesive to form a stable, lightweight and flexible composite system, and cured in a vacuum autoclave to improve the stability of the battery module structure, thereby significantly improving the reliability and service life of the battery module in multiple harsh environments at low orbits. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 A schematic diagram of the structure of a flexible gallium arsenide battery assembly for a low-orbit satellite;

[0060] Reference numerals: 1. Flexible glass cover; 2. First layer of modified polyimide film; 3. Transparent antistatic coating; 4. Flexible gallium arsenide battery chip; 5. Adhesive; 6. Second layer of modified polyimide film; 7. Flexible metal substrate. Detailed Implementation

[0061] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0064] Example 1:

[0065] like Figure 1 As shown, the flexible gallium arsenide battery module of the present invention consists of seven main structural layers from top to bottom.

[0066] First, prepare a flexible glass cover plate 1 with a thickness of 50μm, and deposit an anti-reflection film and an anti-radiation film on its outer surface by magnetron sputtering.

[0067] The polyimide film was modified according to the following method to obtain the modified polyimide film:

[0068] Q1 uses tetraethyl orthosilicate as a precursor to prepare a sol, and forms a wet film with a thickness of about 100 nm on the surface of a polyimide film by slit coating.

[0069] Q2 The wet film is sent into the plasma chamber and bombarded with plasma under an argon atmosphere to activate the surface and initially densify the sol layer.

[0070] Q3. Under the condition of continuous plasma, a mixed reactive gas of hexamethyldisiloxane and oxygen is gradually introduced. By controlling the gas ratio and plasma parameters, a layer of SiO2 with a total thickness of approximately 200 nm and a chemical composition gradient from the inside to the outside is finally formed on the surface of polyimide. X Ceramic coating.

[0071] The adhesive was prepared according to the following method: 100 parts by weight of silicone resin prepolymer with 30% phenyl content was used as the base polymer, and 10 parts by weight of SiO2 hollow ceramic microspheres with a particle size of 200 nm, 2 parts by weight of aminosilane coupling agent, 0.005 parts by weight of platinum catalyst and 0.005 parts by weight of corresponding inhibitor were added. The mixture was uniformly mixed in a clean environment to obtain the adhesive.

[0072] Then, perform lamination encapsulation according to the following steps:

[0073] S1 uses a second layer of modified polyimide film 6 with a thickness of 15μm and a surface modified with silicon oxide as the bottom layer, and attaches it to a titanium foil 7 with a thickness of 100μm by coating it with adhesive 5;

[0074] S2 After the prepared flexible gallium arsenide battery chip 4 is interconnected with silver paste or conductive adhesive, it is fixed on the second modified polyimide film 6 with adhesive 5.

[0075] S3 employs physical vapor deposition to deposit a transparent antistatic coating 3 on the entire battery chip array and the exposed second layer of modified polyimide film 6, controlling the sheet resistance at 10. 5 Ω / □ (approximately);

[0076] S4 uses another piece of the same specification first-layer modified polyimide film 2 as the upper layer, and covers it on the transparent antistatic coating 3 with adhesive 5;

[0077] S5 uses adhesive 5 to laminate the prepared flexible glass cover 1 to the top layer, forming a sandwich structure;

[0078] S6 places the entire sandwich structure into a vacuum autoclave and cures it at 150°C and 0.5MPa for 2 hours, allowing the adhesive 5 to fully crosslink and eliminate interlayer bubbles, forming a dense and strong whole.

[0079] Example 2:

[0080] like Figure 1 As shown, the flexible gallium arsenide battery module of the present invention consists of seven main structural layers from top to bottom.

[0081] First, prepare a flexible glass cover plate 1 with a thickness of 30μm, and deposit an anti-reflection film and an anti-radiation film on its outer surface by magnetron sputtering.

[0082] The 25 μm and 10 μm polyimide films were modified according to the following method to obtain modified polyimide films:

[0083] Q1 uses aluminum isopropoxide as a precursor to prepare a sol, and forms a wet film with a thickness of about 150 nm on the surface of a polyimide film by slit coating.

[0084] Q2 The wet film is sent into the plasma chamber and bombarded with plasma under an argon atmosphere to activate the surface and initially densify the sol layer.

[0085] Q3. Under the condition of continuous plasma, a mixed reactive gas of trimethylaluminum and oxygen is gradually introduced. By controlling the gas ratio and plasma parameters, an AlO layer with a total thickness of approximately 250 nm and a chemical composition gradient from the inside to the outside is finally formed on the polyimide surface. X Ceramic coating.

[0086] The adhesive was prepared according to the following method: 100 parts by weight of silicone resin prepolymer with 25% phenyl content was used as the base polymer, and 10 parts by weight of Al2O3 hollow ceramic microspheres with a particle size of 300 nm, 1.5 parts by weight of aminosilane coupling agent, 0.003 parts by weight of platinum catalyst and 0.003 parts by weight of corresponding inhibitor were added. The mixture was uniformly mixed in a clean environment to obtain the adhesive.

[0087] Then, perform lamination encapsulation according to the following steps:

[0088] S1 uses a second layer of modified polyimide film 6 with a base thickness of 10 μm and an alumina-modified surface as the bottom layer, and is bonded to a molybdenum foil 7 with a thickness of 150 μm by coating it with adhesive 5;

[0089] S2 After the prepared flexible gallium arsenide battery chip 4 is interconnected with silver paste or conductive adhesive, it is fixed on the second modified polyimide film 6 with adhesive 5.

[0090] S3 employs physical vapor deposition to deposit a transparent antistatic coating 3 on the entire battery chip array and the exposed second layer of modified polyimide film 6, controlling the sheet resistance at 10. 6 Ω / □ (approximately);

[0091] S4 uses another base layer of 25μm thick modified polyimide film 2 as the top layer, and covers it on the transparent antistatic coating 3 with adhesive 5;

[0092] S5 uses adhesive 5 to laminate the prepared flexible glass cover 1 to the top layer, forming a sandwich structure;

[0093] S6 places the entire sandwich structure into a vacuum autoclave and cures it for 3 hours at 130°C and 0.8MPa, allowing the adhesive 5 to fully crosslink and eliminate interlayer bubbles, forming a dense and strong whole.

[0094] Comparative Example 1:

[0095] Unlike Example 1, neither of the two polyimide films used in this comparative example were modified according to the modification method in Example 1.

[0096] Comparative Example 2

[0097] Unlike Example 1, this comparative example uses a specially formulated phenyl silicone rubber instead of adhesive 5, and the curing parameters are adjusted to: temperature 180°C, pressure 0.2 MPa, and curing time 1 h.

[0098] Comparative Example 3:

[0099] Unlike Example 1, this comparative example uses only a 50μm ordinary modified polyimide film as a cover, which is directly covered onto the GaAs battery array by adhesive 5. The battery array is directly pasted onto a rigid composite material plate, and the encapsulation method adopts conventional lamination encapsulation.

[0100] Comparative Example 4:

[0101] Unlike Example 1, this comparative example uses a 50 μm conventional modified polyimide film instead of the flexible metal substrate of the present invention.

[0102] After all samples were prepared, the following tests were performed:

[0103] Initial photoelectric efficiency: Photoelectric conversion efficiency under simulated sunlight (AM0).

[0104] Mass loss and efficiency degradation after atomic oxygen testing: test data from a ground-based simulator exposed to an equivalent 5-year low-Earth orbit atomic oxygen flux.

[0105] Efficiency decay after UV irradiation test: equivalent to 3 years of low-orbit UV irradiation dose.

[0106] Interconnection integrity rate after high and low temperature cycling: the percentage of intact electrical connections of the battery interconnect strip after 5000 cycles from -100℃ to +100℃.

[0107] Electrostatic discharge protection capability: Tested according to relevant standards to determine whether destructive electrostatic discharge (ESD) occurs.

[0108] Flexibility (bending radius): The minimum bending radius that a component can withstand without performance degradation or structural damage.

[0109] Areal density: mass per unit area, used to assess the level of lightweighting.

[0110] After the above tests, the data in Table 1 were obtained:

[0111] Table 1. Test data for the examples and comparative examples:

[0112]

[0113] By comparing the data from the above examples and comparative examples, it can be seen that:

[0114] Comparative Example 1 showed severe mass loss and efficiency degradation after the atomic oxygen test, proving that ordinary organic polyimide is completely unable to resist low-orbit atomic oxygen corrosion. In contrast, the gradient ceramic modified layer of this invention significantly improves protective performance with extremely low efficiency degradation.

[0115] Comparative Example 2 showed a sharp drop in interconnect integrity rate to 82.3% after high and low temperature cycling, far lower than the level of the Example. This is because the rigid epoxy adhesive cannot buffer the thermal stress between the layers, causing stress concentration at the fragile battery interconnect points and resulting in breakage. In contrast, the low-modulus, high-elasticity phenyl silicone of this invention acts as a highly efficient stress buffer layer, ensuring structural integrity under extreme temperatures, which is not achievable with conventional adhesives.

[0116] Comparative Example 3 showed poor performance in atomic oxygen and ultraviolet protection, and had high areal density but no ESD protection. In contrast, the embodiments of the present invention achieved lightweight and comprehensive environmental adaptability while maintaining excellent protection. This demonstrates that combining flexible glass cover, modified polyimide film, transparent antistatic coating, flexible metal substrate, etc., produces technical effects far exceeding those of single components or traditional combinations.

[0117] Although Comparative Example 4 is lighter and slightly more flexible, its interconnect integrity rate after high and low temperature cycling is lower than that of Example 1, and its heat dissipation is poor in practical applications, which may lead to an increase in battery operating temperature. This indicates that flexible metal substrates play an irreplaceable role in providing rigid support, matching CTE to reduce interface stress, and enhancing lateral heat dissipation, and are key to ensuring the long-term on-orbit operation of high-performance flexible batteries.

[0118] In summary, this invention addresses the problems of atomic oxygen erosion, thermal stress failure, and electrostatic discharge faced by low-orbit flexible solar cells through a series of interconnected and mutually supportive technical means, including modified polyimide films, adhesives, and multilayer rigid-flexible synergistic structures.

[0119] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A flexible gallium arsenide battery module for low-Earth orbit satellites, characterized in that, From top to bottom, they are: Flexible glass cover; The first layer of modified polyimide film; Transparent antistatic coating; Flexible gallium arsenide battery chip array; The second layer is a modified polyimide film; Flexible metal substrate; The layers are pressed together using adhesive; The modified polyimide film is a polyimide film whose surface has been modified with silicon oxide or aluminum oxide.

2. The flexible gallium arsenide battery module for low-Earth orbit satellites and its packaging method according to claim 1, characterized in that, The modification method of the polyimide film includes: Q1 uses tetraethyl orthosilicate or aluminum isopropoxide as a precursor to prepare a sol, and forms a wet film with a thickness of 50~200nm on the surface of a polyimide film by slit coating. Q2. A polyimide film coated with a wet film is sent into the plasma chamber and bombarded with plasma in an inert gas atmosphere. Q3. Under the condition of continuous plasma, a reaction gas is gradually introduced to obtain the modified polyimide film; the reaction gas is hexamethyldisiloxane and oxygen or trimethylaluminum and oxygen.

3. The flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 2, characterized in that, The thickness of the polyimide film is 10~25μm.

4. The flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 1, characterized in that, The flexible glass cover has a thickness of 30~100μm, and its side facing the space is coated with an anti-reflective film and an anti-radiation film.

5. The flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 1, characterized in that, The transparent antistatic coating is a tin-doped indium oxide or fluorine-doped tin oxide transparent conductive coating with a sheet resistance range of 10. 3 ~10 6 Ω / □.

6. The flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 1, characterized in that, Individual battery chips in the flexible gallium arsenide battery chip array are electrically connected by flexible interconnect strips, which are made of copper-clad polyimide substrate.

7. The flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 1, characterized in that, The adhesive is prepared by: The product is prepared by mixing 100 parts of a silicone resin prepolymer with a phenyl content of 25-35% as the base polymer with 5-15 parts of hollow ceramic microspheres with a particle size of 100-500 nm, 1-3 parts of a silane coupling agent, 0.001-0.01 parts of a platinum catalyst and 0.0005-0.02 parts of an inhibitor.

8. The flexible gallium arsenide battery module for low-Earth orbit satellites and its packaging method according to claim 1, characterized in that, The flexible metal substrate is a titanium foil or molybdenum foil with a thickness of 50~150μm.

9. The packaging method for a flexible gallium arsenide battery module for low-Earth orbit satellites according to any one of claims 1 to 8, characterized in that, include: In a clean environment, the second layer of modified polyimide film is attached to the flexible metal substrate using the adhesive to form a bottom composite structure. S2 fixes the flexible gallium arsenide battery chip array to the underlying composite structure using the adhesive; S3 prepares the transparent antistatic coating on the surface of the battery chip array and the underlying composite structure; S4. The first layer of modified polyimide film is covered onto the transparent antistatic coating with the adhesive to form an intermediate composite structure; S5 Presses the flexible glass cover onto the top layer of the intermediate composite structure using the adhesive; S6 places the overall structure obtained in S5 into a vacuum autoclave for curing, thus completing the encapsulation.

10. The packaging method for a flexible gallium arsenide battery assembly for low-Earth orbit satellites according to claim 9, characterized in that, The curing parameters are: curing temperature of 120~180℃, pressure of 0.3~0.8MPa, and curing time of 1~3h.

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