A battery assembly and a method of manufacturing a battery assembly

Abstract

This application provides a battery module and a method for manufacturing the battery module, specifically relating to the field of battery technology. The battery module includes a backsheet, a light-transmitting plate, a cell array, and an encapsulation structure. The cell array is disposed between the backsheet and the light-transmitting plate, and includes several cells arranged in an array, with adjacent cells electrically connected by conductive adhesive. The encapsulation structure is located on both sides of the cell array along its height, and an ion-scavenging agent is added to the encapsulation structure. Thus, the battery module provided by this application reduces contact resistance and current transmission loss by setting conductive adhesive interconnects between the cells, thereby increasing the output power of the battery module. Furthermore, by adding an ion-scavenging agent to the encapsulation structure, ion migration within the encapsulation structure is suppressed, thereby improving the battery module's resistance to PID (Potential Influence of Degradation) and extending its outdoor lifespan.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery module and a method for manufacturing the battery module. Background Technology

[0002] In photovoltaic power generation systems, back-contact solar modules are widely used in distributed energy systems, commercial rooftop photovoltaics, ground-mounted photovoltaic power plants, and high-end building-integrated photovoltaics (BIPV) due to their high conversion efficiency and back-contact design, where the electrodes are located on the back of the solar cell.

[0003] As the global energy structure shifts towards clean energy, the performance stability, cost control, and environmental adaptability of photovoltaic modules have become core requirements for the industry's development. Existing back-contact solar modules mainly consist of solar cells, tin-plated copper interconnect strips, ethylene-vinyl acetate copolymer (EVA) film, glass, and a backsheet. The interconnect strips are connected to the back electrodes of the solar cells by high-temperature brazing, and then the modules are laminated and encapsulated at a high temperature of 140-160℃.

[0004] However, in existing battery modules, the high-temperature welding and lamination processes during manufacturing can easily damage the passivation layer of the cells, generating thermal stress and accelerating efficiency degradation. Simultaneously, gaps are prone to exist at the interface between the tin-plated copper interconnects and the electrodes, resulting in high contact resistance and current transmission losses. EVA films are susceptible to ion migration during long-term use, leading to weak resistance to PID (potential-induced degradation) and rapid outdoor power degradation. Furthermore, the fixed cell arrangement cannot adapt to non-uniform lighting conditions, easily forming localized hot spots and further reducing the overall performance of the battery module. Summary of the Invention

[0005] This application provides a battery module and a method for manufacturing the battery module. By setting conductive adhesive interconnecting strips between the battery cells, contact resistance is reduced, current transmission loss is decreased, and the output power of the battery module is improved. In addition, by adding an ion trapping agent to the encapsulation structure, ion migration in the encapsulation structure is suppressed, thereby improving the battery module's resistance to PID and extending its outdoor service life.

[0006] The first aspect of this application provides a battery assembly, comprising:

[0007] Back panel;

[0008] Translucent panel;

[0009] A solar cell array is disposed between a backplate and a light-transmitting plate. The solar cell array consists of several solar cells arranged in an array, and adjacent solar cells are interconnected and electrically connected by conductive adhesive.

[0010] The encapsulation structure is located on both sides of the cell pack along the height direction, and an ion trapping agent is added to the encapsulation structure.

[0011] The battery module provided in the first aspect of this application includes a backsheet, a light-transmitting plate, a battery cell array, and an encapsulation structure. The battery cell array is disposed between the backsheet and the light-transmitting plate, and includes a plurality of battery cells arranged in an array. Adjacent battery cells are electrically connected by conductive adhesive. The encapsulation structure is located on both sides of the battery cell array along its height, and an ion-scavenging agent is added to the encapsulation structure. Thus, the battery module provided in this application reduces contact resistance and current transmission loss by providing conductive adhesive interconnects between the battery cells, thereby increasing the output power of the battery module. Furthermore, by adding an ion-scavenging agent to the encapsulation structure, ion migration within the encapsulation structure is suppressed, thereby improving the battery module's resistance to PID (Potential Influenced Processing) and extending its outdoor service life.

[0012] In one possible implementation, the side of the battery cell facing the conductive adhesive interconnect strip has an electrode layer, which is attached to the conductive adhesive interconnect strip.

[0013] In one possible implementation, the conductive adhesive interconnect tape is a flexible interconnect tape, and the conductive adhesive interconnect tape forms an electrical and physical connection with the electrode layer through low-temperature curing of conductive adhesive.

[0014] In one possible implementation, the electrode layer is a nano-nickel layer plated on the surface of the battery cell, and the thickness of the nano-nickel layer is 50 nm.

[0015] In one possible implementation, the packaging structure includes a first packaging layer and a second packaging layer;

[0016] The first encapsulation layer is located between one side of the cell assembly and the backsheet, and the second encapsulation layer is located between the other side of the cell assembly and the light-transmitting plate.

[0017] In one possible implementation, the first encapsulation layer and / or the second encapsulation layer are modified encapsulation films with added ion trapping agents, wherein the modified encapsulation film is a modified POE film.

[0018] In one possible implementation, a positioning pad is provided between adjacent solar cells to adjust the spacing between the solar cells.

[0019] In one possible implementation, the adjustable spacing between adjacent solar cells is 5-8 mm.

[0020] A second aspect of this application provides a method for preparing a battery module, comprising:

[0021] The solar cells are cleaned, and the electrode layer on the surface of the solar cells is subjected to plasma activation treatment.

[0022] Several battery cells are arranged using positioning pads, and conductive adhesive interconnecting tape is attached to the electrode layer. The cells are then cured under pressure at low temperature to form a battery cell assembly.

[0023] The backsheet, first encapsulation layer, cell pack, second encapsulation layer and light-transmitting plate are stacked and laminated at a temperature of less than or equal to 90°C to obtain a battery module.

[0024] In one possible implementation, the temperature range for pressure curing of the battery cell assembly is 80-90°C.

[0025] It should be understood that the second aspect of this application corresponds to the technical solution of the first aspect of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be repeated here.

[0026] In addition to the technical problems solved by this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that can be solved by a battery module and a method for preparing the battery module provided by this application, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only a part of the embodiments of this application. These drawings and text descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the battery assembly provided in an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the conductive adhesive interconnect strip of the battery assembly provided in an embodiment of this application;

[0030] Figure 3 This is a schematic flowchart illustrating the method for preparing a battery module according to an embodiment of this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100 - Battery assembly;

[0033] 200-back panel;

[0034] 300-Transparent Panel;

[0035] 400 - Cell pack; 410 - Cell; 411 - Electrode layer; 420 - Conductive adhesive interconnect tape; 421 - Conductive adhesive layer; 422 - Substrate layer; 430 - Positioning pad;

[0036] 500 - Package structure; 510 - First package layer; 520 - Second package layer. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0038] As described in the background section, in existing battery modules, the manufacturing process involves high-temperature welding and lamination, which can easily damage the passivation layer of the cells, generating thermal stress and accelerating efficiency degradation. Simultaneously, gaps are prone to exist at the interface between the tin-plated copper interconnects and the electrodes, resulting in high contact resistance and current transmission losses. EVA films are susceptible to ion migration during long-term use, leading to weak resistance to PID (potential-induced degradation) and rapid outdoor power degradation. Furthermore, the fixed cell arrangement cannot adapt to non-uniform lighting conditions, easily forming localized hot spots and further reducing the overall performance of the battery module.

[0039] To address the aforementioned technical problems, the first aspect of this application provides a battery assembly. The battery assembly includes a backsheet, a light-transmitting plate, a cell array, and an encapsulation structure. The cell array is disposed between the backsheet and the light-transmitting plate, and comprises a plurality of cells arranged in an array, with adjacent cells electrically connected by conductive adhesive. The encapsulation structure is located on both sides of the cell array along its height, and an ion-scavenging agent is added to the encapsulation structure. Thus, the battery assembly provided by this application reduces contact resistance and current transmission loss by providing conductive adhesive interconnects between the cells, thereby increasing the output power of the battery assembly. Furthermore, by adding an ion-scavenging agent to the encapsulation structure, ion migration within the encapsulation structure is suppressed, thereby improving the battery assembly's resistance to PID (Potential Influence of Degradation) and extending its outdoor service life.

[0040] The second aspect of this application provides a method for preparing a battery module. The method includes cleaning the battery cells and performing plasma activation treatment on the electrode layers on the surface of the battery cells; arranging several battery cells using positioning pads, attaching conductive adhesive interconnecting tapes to the electrode layers, and curing under pressure at low temperature to form a battery cell assembly; and stacking a backplate, a first encapsulation layer, the battery cell assembly, a second encapsulation layer, and a light-transmitting plate, and laminating them at a temperature of less than or equal to 90°C to obtain the battery module.

[0041] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] This application provides a battery module and a method for manufacturing the battery module. By setting conductive adhesive interconnecting strips between the battery cells, contact resistance is reduced, current transmission loss is decreased, and the output power of the battery module is improved. Furthermore, by adding an ion trapping agent to the encapsulation structure, ion migration within the encapsulation structure is suppressed, thereby improving the battery module's resistance to PID (Potential Influenced Processing) and extending its outdoor lifespan. The specific structure of the battery module and its manufacturing method provided in this application will be described below with reference to the accompanying drawings.

[0043] refer to Figure 1 This application provides a battery assembly 100 in a first aspect. The battery assembly 100 may include a backplate 200, a light-transmitting plate 300, a battery cell array 400, and an encapsulation structure 500. In this application embodiment, the battery cell array 400 may be disposed between the backplate 200 and the light-transmitting plate 300. The battery cell array 400 may include battery cells 410 arranged in an array, and adjacent battery cells 410 may be electrically connected by conductive adhesive interconnecting tapes 420. In one possible implementation, the number of battery cells 410 may be several, and this application embodiment does not limit this.

[0044] Exemplarily, in one possible implementation, the back panel 200 may be a fluorocarbon back panel 200, and the light-transmitting panel 300 may be an ultra-clear anti-reflective glass. The embodiments described in this application are not intended to be limiting.

[0045] Continue to refer to Figure 1Based on the above embodiments, the encapsulation structure 500 can be located on both sides of the battery cell pack 400 along the height direction, and an ion trapping agent can be added to the encapsulation structure 500. In the embodiments of this application, it is understood that by adding an ion trapping agent to the encapsulation structure 500, ion migration in the encapsulation structure 500 is suppressed, thereby improving the potential-induced degradation (PID) resistance of the battery module 100 and extending its outdoor service life.

[0046] Thus, the battery module 100 provided in this application embodiment reduces contact resistance and current transmission loss by providing conductive adhesive interconnecting strips 420 between the battery cells 410, thereby increasing the output power of the battery module 100. Furthermore, by adding an ion trapping agent to the encapsulation structure 500, the migration of alkali metal ions such as sodium and potassium in the encapsulation material can be effectively suppressed, thereby significantly improving the battery module 100's resistance to PID and extending its service life in outdoor high-temperature and high-humidity environments.

[0047] By replacing the traditional tin-plated copper interconnect strips with conductive adhesive interconnect tape 420, which has extremely low resistivity, the contact resistance between the solar cells 410 is significantly reduced, thereby reducing Joule heat loss during current transmission and directly improving the overall output power of the solar module 100. Secondly, the flexibility and low-temperature curing properties of the conductive adhesive interconnect tape 420 prevent thermal stress damage to the ultra-thin solar cells 410 caused by high-temperature welding. Meanwhile, its excellent shear strength and wide temperature range ensure the mechanical reliability of the interconnect structure under long-term thermal cycling.

[0048] Continue to refer to Figure 1 Based on the above embodiments, the side of the battery cell 410 facing the conductive adhesive interconnect tape 420 may be provided with an electrode layer 411, and the electrode layer 411 may be attached to the conductive adhesive interconnect tape 420.

[0049] In a specific embodiment, the electrode layer 411 can be a nanoscale metal layer directly formed on the surface of the battery cell 410 through a plating process. In this embodiment, the electrode layer 411 and the conductive adhesive interconnect tape 420 can achieve a gapless physical adhesion, thus providing a suitable interface for subsequent electrical connections and mechanical fixation.

[0050] In this embodiment, it is understood that by pre-setting a flat and continuous electrode layer 411 on the battery cell 410, a larger effective contact area is provided for the conductive adhesive interconnect strip 420. Compared with dot-shaped or linear grid electrodes, this further reduces contact resistance, resulting in more uniform and efficient current collection. Simultaneously, the direct bonding between the electrode layer 411 and the conductive adhesive interconnect strip 420 avoids localized overheating caused by poor contact, thus improving the long-term operational stability of the battery assembly 100.

[0051] refer to Figure 1 as well as Figure 2 Based on the above embodiments, the conductive adhesive interconnect tape 420 can be a flexible interconnect tape, and the conductive adhesive interconnect tape 420 can form an electrical connection and a physical connection with the electrode layer 411 through low-temperature curing of conductive adhesive. In the embodiments of this application, the conductive adhesive flexible interconnect tape may include a conductive adhesive layer 421 and a substrate layer 422, wherein the conductive adhesive layer 421 and the substrate layer 422 may be stacked along the height direction.

[0052] In a specific embodiment, the conductive adhesive interconnect tape 420 can use copper foil as the base layer 422, which has excellent bending performance. Furthermore, the surface of the conductive adhesive interconnect tape 420 is coated with an isocyanate-modified epoxy resin conductive adhesive layer 421, which can be filled with silver nanowires or silver powder, and its resistivity is controlled to ≤5×10⁻⁶. -6 Ω·cm. The conductive adhesive interconnect tape 420 is flexible and can achieve complete cross-linking and curing within 10-15 minutes under a low temperature environment of 80-90℃ and a uniform pressure of 0.1-0.2MPa. After curing, the volume resistivity is ≤5×10 Ω·cm. -6 The shear strength of the bond between the electrode layer 411 and the electrode layer can reach over 15 MPa (Ω·cm). Furthermore, it maintains stable performance over a long period within a temperature range of -40℃ to 85℃.

[0053] In the embodiments of this application, it is understood that the flexible substrate and low-temperature curing process perfectly meet the encapsulation requirements of thin-film, large-size battery cells 410, effectively avoiding thermal damage problems such as microcracks and bending of battery cells 410 caused by traditional high-temperature welding, and reducing the breakage rate. At the same time, the conductive adhesive interconnect tape 420 ensures extremely low bulk resistivity, while the high shear strength ensures that the conductive adhesive interconnect tape 420 will not debond or slip relative to each other during the lamination of the battery module 100 and subsequent use, and can maintain stable and reliable electrical interconnection even under harsh temperature cycling from -40℃ to 85℃.

[0054] Based on the above embodiments, in one possible implementation, exemplarily, the electrode layer 411 can be a nano-nickel layer plated on the surface of the battery cell 410, and the thickness of the nano-nickel layer can be 50 nm. Specifically, the nano-nickel layer can be uniformly deposited on the metallization region of the battery cell 410 using an electroplating process, with the thickness precisely controlled at around 50 nm, forming a dense, uniform, and well-bonded conductive transition layer with the substrate.

[0055] In the embodiments of this application, it is understood that the nanoscale nickel layer thickness greatly reduces the consumption of precious metals (such as silver), significantly reducing the manufacturing cost of the solar cell 410. Simultaneously, nickel possesses excellent oxidation and corrosion resistance; the dense 50nm nickel layer effectively blocks the diffusion of external moisture and ions from the encapsulation structure 500 into the solar cell 410, protecting the core structure of the solar cell 410.

[0056] Continue to refer to Figure 1 Based on the above embodiments, in one possible implementation, the encapsulation structure 500 may include a first encapsulation layer 510 and a second encapsulation layer 520. In this embodiment, the first encapsulation layer 510 may be located between one side of the battery cell assembly 400 and the backplate 200, while the second encapsulation layer 520 may be located between the other side of the battery cell assembly 400 and the light-transmitting plate 300.

[0057] In a specific implementation, the first encapsulation layer 510 and the second encapsulation layer 520 can completely enclose the battery cell pack 400, while the back plate 200 and the light-transmitting plate 300 serve as the outermost protective and support structure, located on both sides respectively.

[0058] In the embodiments of this application, it is understood that by layering the encapsulation structure 500, the performance of the encapsulation material can be optimized for different interfaces (cell 410-backsheet 200, cell 410-light-transmitting plate 300). For example, the second encapsulation layer 520 facing the light-transmitting plate 300 requires higher light transmittance, while the first encapsulation layer 510 facing the backsheet 200 focuses more on reflection and insulation. This arrangement ensures that the cell assembly 400 can be completely sealed in an oxygen-free and water-free environment, effectively isolating external environmental stress, while providing a uniformly distributed carrier space for the added ion trapping agent.

[0059] Continue to refer to Figure 1 Based on the above embodiments, in one possible implementation, the first encapsulation layer 510 and / or the second encapsulation layer 520 may be a modified encapsulating film with added ion trapping agents. Exemplarily, the modified encapsulating film is a modified polyolefin elastomer (POE) film. The embodiments described in this application are not intended to be limiting.

[0060] In a specific embodiment, a composite ion scavenger with a mass ratio of 2-5% is added to the modified POE film. The ion scavenger is composed of rare earth oxides (such as CeO2) and zeolite molecular sieve composite powder. The modified POE film can achieve complete cross-linking at a temperature ≤90℃ for 15-20 minutes, with a cross-linking degree ≥85%. Its key performance indicators are: capture efficiency of alkali metal ions such as Na⁺ and K⁺ ≥90%, and inhibition effect on ion mobility ≥80%; at the same time, the water vapor permeability of the film is ≤2g / (m²·d), and the volume resistivity is ≥1×10⁻⁶. 16 Ω·cm, and after 1000 hours of UV aging, the transmittance retention rate is still ≥95%.

[0061] In the embodiments of this application, it is understood that, firstly, the added CeO2 and zeolite molecular sieve composite powder can efficiently and rapidly chemically adsorb and fix Na⁺, K⁺, and other ions migrating from the glass or backing plate 200, increasing the ion capture rate to over 90%, thereby fundamentally cutting off the ion conduction path where the PID effect occurs and suppressing the migration rate by more than 80%. Secondly, the modified POE film itself has extremely low water vapor transmission rate (≤2g / (m²·d)) and ultra-high volume resistivity (≥1×10⁻⁶). 16 The modified POE film, with a crosslinking efficiency of ≥85% at 90℃, further enhances the insulation and waterproofing performance of the module. More importantly, it achieves a high crosslinking degree of ≥85% at a low temperature, perfectly matching the low-temperature curing window of the conductive adhesive and enabling thermal compatibility between encapsulation and interconnection processes. Finally, its excellent UV aging resistance (1000h transmittance retention ≥95%) ensures that the module maintains high photoelectric conversion efficiency during long-term outdoor use.

[0062] Continue to refer to Figure 1 Based on the above embodiments, in one possible implementation, a positioning pad 430 may be provided between adjacent battery cells 410. In this embodiment, it is understood that the positioning pad 430 can be used to adjust the spacing between the battery cells 410.

[0063] During assembly, the positioning pad 430 is placed between the edges of adjacent solar cells 410 as a physical spacer, which can precisely control and maintain a uniform spacing between cells.

[0064] In the embodiments of this application, it is understood that the use of positioning pads 430 enables the solar cells 410 to resist the influence of adhesive flow or external forces during the arrangement and subsequent bonding and lamination of conductive adhesive, maintaining a preset uniform gap. This avoids short circuits or contact at the edges of adjacent solar cells 410 due to excessively small spacing, and also prevents waste of module area caused by excessively large spacing, thereby maximizing the effective power generation area of ​​the module while ensuring electrical safety.

[0065] Continue to refer to Figure 1 Based on the above embodiments, in one possible implementation, the adjustable spacing between adjacent battery cells 410 is 5-8 mm. By selecting positioning pads 430 of different thicknesses or specifications, the spacing between adjacent battery cells 410 can be precisely controlled within the range of 5 mm to 8 mm.

[0066] In the embodiments of this application, it is understood that setting the spacing within the range of 5-8mm, after optimization and verification, can provide sufficient creepage distance and electrical isolation space, effectively preventing arcing or leakage between the edges of adjacent solar cells 410 in high humidity environments. Simultaneously, this spacing also provides ample allowance for the bending deformation and stress release of the flexible conductive adhesive interconnect strip 420, avoiding fatigue fracture of the interconnect strip in a confined space, thus balancing module space utilization with long-term electrical reliability.

[0067] refer to Figure 3 This application provides a method for preparing a battery module 100 in a second aspect. The method may include: cleaning the battery cells 410 and performing plasma activation treatment on the electrode layer 411 on the surface of the battery cells 410; arranging several battery cells 410 using positioning pads 430, attaching conductive adhesive interconnecting tapes 420 to the electrode layer 411, and pressing and curing at low temperature to form a battery cell assembly 400; and stacking a backplate 200, a first encapsulation layer 510, the battery cell assembly 400, a second encapsulation layer 520, and a light-transmitting plate 300, and laminating and encapsulating them at a temperature of less than or equal to 90°C to obtain the battery module 100.

[0068] Figure 3 A schematic flowchart illustrating a method for fabricating a battery module 100 according to an embodiment of this application is provided, referring to... Figure 3 As shown in the embodiment of this application, a method for manufacturing a battery module 100 includes:

[0069] S301. Clean the battery cell 410 and perform plasma activation treatment on the electrode layer 411 on the surface of the battery cell 410.

[0070] In this embodiment, the battery cell 410 is first cleaned using ultrasonic cleaning or spraying. Deionized water, ethanol, or a special cleaning agent are used to remove organic contaminants, cutting residues, fingerprints, dust, and other impurities from the surface of the battery cell 410, especially the electrode layer 411. After cleaning, it is dried with nitrogen and then dried at a low temperature. Subsequently, the cleaned and dried battery cell 410 is placed in a plasma processing chamber. After evacuation, oxygen, argon, or a mixture thereof are introduced, and radio frequency or microwave power is applied. The active particles in the plasma bombard and modify the surface of the electrode layer 411, introducing polar functional groups and changing the surface from hydrophobic to hydrophilic. This significantly reduces the contact angle, thereby improving the bonding reliability and electrical contact performance between the subsequent conductive adhesive interconnect tape 420 and the electrode layer 411. The treated battery cell 410 should proceed to the next process as soon as possible to avoid surface activity decay.

[0071] S302. Arrange several battery cells 410 using positioning pads 430, attach conductive adhesive interconnecting tape 420 to electrode layer 411, and cure under pressure at low temperature to form battery cell group 400.

[0072] In this embodiment, the activated solar cells 410 are precisely arranged on the positioning pad 430 according to the design, ensuring accurate alignment of the electrode positions of adjacent solar cells 410. Then, conductive adhesive interconnect tapes 420 of appropriate length are cut. One end of the conductive adhesive interconnect tape 420 is aligned with the front electrode of one solar cell 410, and the other end is connected across the back electrode or another electrode of the adjacent solar cell 410. A patch tool is used to gently press the conductive adhesive interconnect tape 420 to initially adhere it, thus completing the electrical connection between all solar cells 410. Finally, the assembly with the interconnect tapes arranged is placed in a pressing device, uniform pressure is applied, and heating is maintained at a low temperature for 5-15 minutes, allowing the resin in the conductive adhesive interconnect tape 420 to crosslink and cure. Under pressure, the conductive particles form a stable conductive path. After natural cooling, a solar cell assembly 400 with fixed electrical connections is obtained.

[0073] S303. The backplate 200, the first encapsulation layer 510, the battery cell group 400, the second encapsulation layer 520 and the light-transmitting plate 300 are stacked and laminated at a temperature of less than or equal to 90°C to obtain the battery module 100.

[0074] In this embodiment, the backplate 200, the first encapsulation layer 510, the cell assembly 400, the second encapsulation layer 520, and the light-transmitting plate 300 are stacked sequentially from bottom to top on the lower tray of the laminator. The stacked assembly is then fed into the laminator chamber, and a vacuum is drawn to -0.08 to -0.1 MPa and maintained for 1 to 3 minutes to remove interlayer bubbles. Under vacuum, the temperature is heated to no more than 90°C (typically 80 to 90°C), while the upper platen applies a pressure of 0.05 to 0.1 MPa. The temperature and pressure are maintained for 10 to 30 minutes, allowing the encapsulation material to melt and flow, fully filling the gaps between the cell 410 and the interconnecting strips, ultimately solidifying to form a dense, transparent, and weather-resistant sealing protective layer. After lamination, the pressure is maintained and cooled to below 50°C. The vacuum is released, and the assembly is removed. Excess encapsulation material overflowing from the edges is trimmed. After visual inspection and electrical testing, a complete battery assembly 100 is obtained.

[0075] In the embodiments of this application, it is understood that plasma activation treatment significantly improves the surface energy of the nano-nickel layer on the surface of the solar cell 410, enhancing its wettability and chemical bonding ability with the conductive adhesive, thereby further reducing contact resistance and improving bonding reliability. The entire preparation process adopts a low-temperature process (≤90℃) throughout, completely avoiding the thermal damage risk brought about by traditional high-temperature processes, making it particularly suitable for the mass production of thin, large-size solar cells 410. At the same time, by using the precise arrangement of positioning pads 430 and low-temperature curing of conductive adhesive, high-precision interconnection of solar cells 410 is achieved, simplifying process steps, reducing equipment investment and energy consumption, and seamlessly connecting with the subsequent low-temperature lamination process, forming a high-efficiency, low-damage, and high-reliability module manufacturing solution.

[0076] Based on the above embodiments, the temperature range for pressure curing of the battery cell pack 400 can be 80-90℃.

[0077] Based on the above embodiments, it can be understood that within a temperature range of 80-90°C, the isocyanate-modified epoxy resin in the conductive adhesive begins to undergo a cross-linking reaction, and with a pressure of 0.1-0.2 MPa, it can be completely cured within 10-15 minutes.

[0078] In the embodiments of this application, it is understood that the curing window of 80-90°C ensures that the conductive adhesive achieves sufficient cross-linking, thereby guaranteeing low resistivity and high shear strength. On the other hand, it precisely avoids the pre-cross-linking risk that may occur with the modified POE encapsulation film above 90°C, allowing the cell assembly 400 to first achieve reliable electrical interconnection before lamination with the encapsulation film. Furthermore, this temperature is far lower than the traditional welding temperature of photovoltaic ribbons, which not only significantly reduces production energy consumption but, more importantly, completely eliminates thermal stress, minimizing the risk of microcracks in the cell 410.

[0079] In this embodiment, the battery assembly 100 provides a reduced contact resistance and reduced current transmission loss by providing conductive adhesive interconnecting strips 420 between the battery cells 410, thereby increasing the output power of the battery assembly 100. Furthermore, by adding an ion trapping agent to the encapsulation structure 500, ion migration within the encapsulation structure 500 is suppressed, thereby improving the battery assembly 100's resistance to PID and extending its outdoor service life.

[0080] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0081] It should be noted that phrases such as "in specific implementations," "in some embodiments," "in this embodiment," and "exemplarily" in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0082] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0083] It should be readily understood that “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0084] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0085] Finally, it should be noted that other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and alterations may be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery assembly, characterized in that, include: Back panel (200); Translucent panel (300); A battery cell assembly (400) is disposed between the back plate (200) and the light-transmitting plate (300). The battery cell assembly (400) includes a plurality of battery cells (410) arranged in an array. Adjacent battery cells (410) are electrically connected by conductive adhesive interconnecting strips (420). An encapsulation structure (500) is located on both sides of the battery cell assembly (400) along the height direction, and an ion trapping agent is added to the encapsulation structure (500).

2. The battery assembly according to claim 1, characterized in that, The battery cell (410) has an electrode layer (411) on the side facing the conductive adhesive interconnect strip (420), and the electrode layer (411) is attached to the conductive adhesive interconnect strip (420).

3. The battery assembly according to claim 2, characterized in that, The conductive adhesive interconnect tape (420) is a flexible interconnect tape, and the conductive adhesive interconnect tape (420) forms an electrical and physical connection with the electrode layer (411) through low-temperature cured conductive adhesive.

4. The battery assembly according to claim 3, characterized in that, The electrode layer (411) is a nano-nickel layer plated on the surface of the battery cell (410), and the thickness of the nano-nickel layer is 50 nm.

5. The battery assembly according to any one of claims 1-4, characterized in that, The encapsulation structure (500) includes a first encapsulation layer (510) and a second encapsulation layer (520); The first encapsulation layer (510) is located between one side of the battery cell assembly (400) and the backplate (200), and the second encapsulation layer (520) is located between the other side of the battery cell assembly (400) and the light-transmitting plate (300).

6. The battery assembly according to claim 5, characterized in that, The first encapsulation layer (510) and / or the second encapsulation layer (520) are modified encapsulation films with added ion trapping agents, wherein the modified encapsulation film is a modified POE film.

7. The battery assembly according to any one of claims 1-4, characterized in that, A positioning pad (430) is provided between adjacent battery cells (410), and the positioning pad (430) is used to adjust the spacing between the battery cells (410).

8. The battery assembly according to claim 7, characterized in that, The adjustable spacing between adjacent battery cells (410) is 5-8 mm.

9. A method for preparing a battery module, characterized in that, include: The battery cell (410) is cleaned and the electrode layer (411) on the surface of the battery cell (410) is subjected to plasma activation treatment; A number of battery cells (410) are arranged using positioning pads (430), and conductive adhesive interconnecting tape (420) is attached to the electrode layer (411). The battery cells are then cured under pressure at low temperature to form a battery cell assembly (400). The backsheet (200), the first encapsulation layer (510), the cell pack (400), the second encapsulation layer (520) and the light-transmitting plate (300) are stacked and laminated at a temperature of less than or equal to 90°C to obtain the battery module (100).

10. The method for preparing a battery module according to claim 9, characterized in that, The temperature range for pressure curing of the battery cell assembly (400) is 80-90℃.

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