Preparation method of solid-state battery of pole piece rubber frame in lamination process and solid-state battery

Abstract

The invention provides a preparation method of a solid-state battery with a lamination process pole piece rubber frame and the solid-state battery, and relates to the technical field of battery manufacturing. The method comprises the following steps: carrying out double-sided insulation paste spraying treatment on a lug root material area of a die-cut positive pole piece, and carrying out curing and drying; laminating the cured and dried positive pole piece on the negative pole piece, applying pressure for fixing, and identifying the material area size of the negative pole piece exceeding the positive pole piece as a gluing area; the outer edge, except the tab part, of the positive plate is used as a gluing track for gluing, the gluing width is smaller than the deviation size after the positive plate and the negative plate are laminated, and the gluing thickness is larger than the thickness of the positive plate; overlapping the negative pole pieces to enable the negative pole pieces to be tightly attached to the positive pole pieces, and arranging glue to simultaneously bond the edges of the two negative pole pieces and the positive pole pieces; and overlapping positive and negative plates and curing to obtain the battery cell. The preparation method provided by the invention solves the problem of battery short circuit caused by transverse displacement of the pole pieces or edge collapse of the positive and negative pole pieces, and improves the stability of the overall structure.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a method for preparing a solid-state battery with an electrode frame in a stacking process, and the solid-state battery itself. Background Technology

[0002] Solid-state batteries, with their high safety performance, long cycle life, and high energy density, have shown broad application prospects in the energy storage field. However, during battery manufacturing, the interfacial adhesion between the solid electrolyte and the positive and negative electrodes has a crucial impact on electrochemical performance, requiring high isostatic pressure to ensure tight contact. During isostatic pressing, the positive and negative electrodes are prone to lateral relative displacement due to pressure. Simultaneously, the electrode edge areas, especially the root and outer edge of the positive electrode tab, often exhibit collapse, curling, or misalignment. Such edge deformation can easily lead to direct contact between the positive and negative electrodes, posing a risk of internal short circuits and severely compromising battery safety and reliability. In the stacking process, the lack of effective fixing methods after electrode alignment makes it impossible to effectively suppress displacement and edge deformation under pressure. Current technologies have not yet solved the problem of stable electrode fixing and edge protection during the stacking process.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing a solid-state battery with an electrode frame in a stacking process, and a solid-state battery, in order to solve the above-mentioned problems.

[0005] To achieve the above objectives, this application adopts the following technical solution: This application provides a method for fabricating a solid-state battery with an electrode frame in a stacking process, comprising: The base area of ​​the electrode tab of the die-cut solid battery positive electrode sheet is coated with insulating adhesive on both sides and then cured and dried. The cured and dried positive electrode sheet is stacked on the negative electrode sheet and fixed with pressure. The area of ​​the negative electrode sheet that exceeds the size of the positive electrode sheet is identified as the coating area. The coating is performed with the outer edge of the positive electrode sheet excluding the tab as the coating trajectory. The coating width is smaller than the deviation size after stacking the positive and negative electrode sheets, and the coating thickness is higher than the thickness of the positive electrode sheet. The negative electrode sheets are stacked to make the negative electrode sheet and the positive electrode sheet fit tightly together. The adhesive simultaneously bonds the two layers of negative electrode sheets and the edges of the positive electrode sheet. Positive and negative electrode sheets are stacked and cured to obtain a cell, which is then assembled into a battery.

[0006] Optionally, the conditions for the double-sided spraying of insulating adhesive are as follows: the thickness of the insulating adhesive is 10-40 μm, the spraying width is 0.3-0.5 mm from the edge of the negative electrode sheet to the material area after the positive and negative electrodes are stacked, and 0.5-2 mm in the direction of the positive electrode tab, and the spraying length completely covers the material area at the root of the electrode tab.

[0007] Optionally, the curing and drying process includes heat drying or light drying.

[0008] Optionally, the alignment error between the positive and negative electrode sheets is no greater than 0.3 mm; the pressure applied after alignment is 300-600 MPa.

[0009] Optionally, the coating is performed using a visual positioning method with the edge of the positive electrode sheet as the coating trajectory, and the coating thickness is 1-1.1 times the thickness of the positive electrode sheet.

[0010] Optionally, the curing includes ultraviolet curing or high-temperature curing.

[0011] Optionally, after curing, the linear shrinkage rate of the adhesive is no greater than 1%; the adhesive does not chemically react with the positive and negative electrode materials; and the hardness of the adhesive is D40-D90.

[0012] Optionally, the Young's modulus E of the adhesive satisfies the following relationship: ΔL = F × h1 / (A × E).

[0013] Optionally, F is the static pressure, ΔL is the compression of the positive electrode sheet thickness under the specified static pressure, h1 is the coating thickness, and A is the area of ​​the coating frame.

[0014] This application also provides a solid-state battery, which is prepared using the method for preparing a solid-state battery with electrode frames in the aforementioned stacking process.

[0015] Compared with the prior art, the beneficial effects of this application include: This application provides a method for fabricating a solid-state battery with an electrode frame in a stacking process, and the solid-state battery itself. Through techniques such as double-sided spraying of insulating adhesive at the base of the electrode tabs, identifying the adhesive application area based on stacking deviations, and implementing edge adhesive fixation, the method effectively achieves stable positioning and edge protection of the positive and negative electrodes. This effectively suppresses lateral relative displacement and edge deformation of the positive and negative electrodes during stacking, avoids internal short circuits, and improves battery safety and reliability. Compared to existing technologies that rely solely on high-voltage bonding, this application's solution utilizes adhesive to form a rigid support frame at the electrode edges, ensuring stable alignment of the positive and negative electrodes during high-voltage bonding. This solves the problem of battery short circuits caused by lateral displacement of the electrodes or collapse of the positive and negative electrode edges, while also improving the overall structural stability of the cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0017] Figure 1 A schematic diagram of the process flow for the fabrication method of a solid-state battery with electrode and adhesive frame in the stacking process provided in the embodiment; Figure 2 This is a schematic diagram of the adhesive application area; Figure 3 The battery cell produced is made from Figure 2 A cross-sectional view along the AA direction. Detailed Implementation

[0018] As used in this article: "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0019] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0020] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0021] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0022] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0023] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0024] To better explain the technical solution provided in this application, the technical solution provided in this application will be described in general before the specific implementation.

[0025] In a first aspect, this application provides a method for preparing a solid-state battery with an electrode frame in a stacking process, comprising: The base area of ​​the electrode tab of the die-cut solid battery positive electrode sheet is coated with insulating adhesive on both sides and then cured and dried. The cured and dried positive electrode sheet is stacked on the negative electrode sheet and fixed with pressure. The area of ​​the negative electrode sheet that exceeds the size of the positive electrode sheet is identified as the coating area. The coating is performed with the outer edge of the positive electrode sheet excluding the tab as the coating trajectory. The coating width is smaller than the deviation size after stacking the positive and negative electrode sheets, and the coating thickness is higher than the thickness of the positive electrode sheet. The negative electrode sheets are stacked to make the negative electrode sheet and the positive electrode sheet fit tightly together. The adhesive simultaneously bonds the two layers of negative electrode sheets and the edges of the positive electrode sheet. Positive and negative electrode sheets are stacked and cured to obtain a cell, which is then assembled into a battery.

[0026] In an optional embodiment, the conditions for the double-sided spraying of insulating adhesive are as follows: the spraying thickness of the insulating adhesive is 10-40 μm, the spraying width is 0.3-0.5 mm from the edge of the negative electrode sheet to the material area after the positive and negative electrodes are stacked, and 0.5-2 mm in the direction of the positive electrode tab, and the spraying length completely covers the material area at the root of the electrode tab.

[0027] Optionally, the coating thickness of the insulating adhesive can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, or any value between 10-50μm; the coating width, after the positive and negative electrodes are stacked, can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, or any value between 0.3-0.5mm from the edge of the negative electrode to the material area; the coating width in the direction of collecting the tabs can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or any value between 0.5-2mm.

[0028] In one alternative implementation, the curing drying includes heat drying or light drying.

[0029] In one optional embodiment, the alignment error between the positive and negative electrode sheets is no greater than 0.3 mm; the pressure applied after alignment is 300-600 MPa.

[0030] Optionally, the alignment error of the positive and negative electrode sheets can be 0.1 mm, 0.2 mm, 0.3 mm, or any value between 0.1 and 0.3 mm; the pressure applied after alignment can be 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, 550 MPa, 600 MPa, or any value between 300 and 600 MPa.

[0031] In one optional embodiment, the coating is performed using a visual positioning method with the edge of the positive electrode sheet as the coating trajectory, and the coating thickness is 1-1.1 times the thickness of the positive electrode sheet.

[0032] Optionally, the coating thickness can be 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, or 1.1 times the thickness of the positive electrode sheet, or any value between 1 and 1.1 times.

[0033] In one optional implementation, the curing includes ultraviolet curing or high-temperature curing.

[0034] In one optional embodiment, after curing, the linear shrinkage rate of the adhesive is no greater than 1%; the adhesive does not chemically react with the positive and negative electrode materials; and the hardness of the adhesive is D40-D90.

[0035] In practical applications, the hardness of adhesive can be understood as the mechanical strength characteristics of the adhesive after curing, which can be achieved by adjusting the crosslinking density in the adhesive formulation or adding reinforcing agents. Specifically, the selection of a hardness range from D40 to D90 combines the need for mechanical strength and adaptability, providing sufficient rigidity to resist external pressure and prevent edge collapse, while retaining appropriate flexibility to absorb dynamic stress during manufacturing and use, thereby ensuring that the adhesive frame stably fixes the electrode sheets throughout the entire battery life without causing stress concentration or breakage.

[0036] In an optional embodiment, the Young's modulus E of the adhesive satisfies the following relationship: ΔL = F × h1 / (A × E).

[0037] In one optional implementation, F is the static pressure, ΔL is the compression of the positive electrode sheet thickness under the specified static pressure, h1 is the coating thickness, and A is the area of ​​the coating frame.

[0038] Specifically, Young's modulus E refers to the ratio of stress to strain in a material during the elastic deformation stage. It can be determined using dynamic mechanical analysis or tensile testing, aiming to quantify the stiffness characteristics of the adhesive under static pressure. This technical solution establishes a quantitative relationship between Young's modulus and compression deformation, ensuring the predictability of the elastic behavior of the adhesive during static pressure. In the lamination process, when the positive and negative electrodes are stacked and pressure is applied, the adhesive in the coating area is compressed. At this time, the range of compression variation can be accurately calculated using the formula ΔL=F×h1 / (A×E). Since the coating thickness h1 directly affects the degree of compression deformation, the value of h1 needs to be reasonably set according to the alignment of the laminations and the specific pressure applied in actual operation. At the same time, the design of the coating frame area A is also crucial; a larger area helps to disperse pressure, thereby reducing the risk of edge collapse. Based on this, by combining the curing conditions and adhesive performance requirements in the above preparation method, such as hardness range and linear shrinkage rate, the stability of the adhesive during isostatic pressing can be further improved, effectively suppressing the problem of lateral displacement and edge collapse of the electrode sheet, and fundamentally avoiding the risk of short circuit.

[0039] Understandably, this method constructs an edge-gluing frame structure during the stacking of positive and negative electrode sheets to effectively constrain the electrode positions, thereby preventing lateral displacement and edge collapse during isostatic pressing. Specifically, firstly, the material area at the root of the electrode tab of the die-cut positive electrode sheet is treated with double-sided spraying of insulating adhesive. Since the root of the electrode tab is a stress concentration area, this treatment can provide targeted insulation protection and mechanical reinforcement, reducing the risk of deformation in this area under high voltage. Furthermore, after curing and drying, the structural strength of the adhesive layer is improved, laying the foundation for subsequent stacking operations. The cured and dried positive electrode sheet is stacked on the negative electrode sheet and pressure is applied to fix it, thereby instantly eliminating the initial gap and enhancing the interface adhesion, reducing the probability of displacement due to loosening. Based on this, the material area of ​​the negative electrode sheet that exceeds the size of the positive electrode sheet is identified as the adhesive application area. The adhesive application range is dynamically determined according to the actual stacking deviation, so that the gluing frame accurately matches the edges prone to misalignment, avoiding insufficient or excessive adhesive application. The adhesive application process follows the outer edge of the positive electrode sheet, excluding the tab portion, creating a continuous adhesive line along the edge contour to reinforce areas at high risk of collapse while avoiding the tab area to prevent interference with electrical connections. The adhesive width is set to be smaller than the deviation dimension after stacking the positive and negative electrodes. The adhesive frame width is rationally designed based on the stacking tolerances to ensure that the adhesive effectively restrains displacement within the error range without overflowing and affecting the bonding quality. The adhesive thickness is greater than the thickness of the positive electrode sheet, increasing lateral support to resist the risk of edge collapse. When stacking the negative electrode sheet, the adhesive simultaneously bonds two layers of negative electrode sheets and the edges of the positive electrode sheet, forming a multi-layered fixing structure that integrates the edges of the positive and negative electrodes into a unified frame. Finally, a curing process completely hardens the adhesive frame, permanently locking the relative positions of the electrodes and ensuring a stable bonding state of the cell during isostatic pressing, fundamentally eliminating the risk of short circuits. Thus, through the synergistic effect of the above steps, the entire technical solution effectively constrains the position of the electrode, solving the problem of lateral displacement of the electrode or collapse and misalignment of the positive and negative electrode edges during isostatic pressing, which leads to short circuits in the battery.

[0040] This application also provides a solid-state battery, which is prepared using the method for preparing a solid-state battery with electrode frames in the aforementioned stacking process.

[0041] In summary, this application constrains the electrode position by constructing an edge-mounted frame structure, preventing lateral displacement and edge collapse during isostatic bonding, thereby avoiding short circuits. Compared to existing technologies that rely solely on high-voltage bonding, this embodiment utilizes adhesive to form a rigid support frame at the electrode edge, ensuring stable alignment of the positive and negative electrodes during high-voltage bonding. This solves the problem of battery short circuits caused by lateral displacement of the electrodes or edge collapse of the positive and negative electrodes, while also improving the overall structural stability of the cell.

[0042] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0043] Example 1 This embodiment provides a method for fabricating a solid-state battery with an electrode and frame in a stacking process. The fabrication process is as follows: Figure 1 As shown, the specific steps are as follows: Select die-cut solid-state battery positive electrode sheets and spray insulating adhesive on both sides of the material area at the base of the electrode tab. The thickness of the insulating adhesive is 10μm, and the spraying width is 0.3mm from the edge of the negative electrode sheet to the material area after stacking the positive and negative electrodes, and 0.5mm in the direction of the positive electrode tab. The length of the sprayed insulating adhesive is to completely cover the material area at the base of the electrode tab. The sprayed insulating adhesive is then cured and dried using UV insulating adhesive, which is cured by UV light for 3 seconds.

[0044] The positive electrode sheet with insulating adhesive is stacked on top of the negative electrode sheet, with an alignment error of no more than 0.3 mm. Pressure is applied to prevent misalignment of the positive and negative electrode sheets. The area of ​​the negative electrode material extending beyond the edge of the positive electrode sheet is the adhesive application area. The edge of the positive electrode sheet is located using visual positioning as the adhesive application trajectory, and adhesive is applied to the adhesive application area on the negative electrode sheet. Adhesive application is continued according to the dimensional deviations of the positive and negative electrode sheets and the size of the adhesive application opening until the adhesive application area is completely covered. Figure 2 As shown, the adhesive coating thickness is 1.1 times the thickness of the positive electrode sheet. The negative electrode sheet is stacked on top of the coated positive electrode sheet, and the surfaces of the upper and lower negative electrode sheets are pressed flat to compact the three sheets. UV light is used for side curing for 3 seconds to fix the positive and negative electrode sheets relatively.

[0045] The adhesive used is a UV adhesive. After curing, the linear shrinkage rate of the adhesive is less than 1%. The adhesive does not react chemically with the positive and negative electrode materials. The hardness of the adhesive meets the requirements of D40 to D90. To ensure that the solid-state battery has sufficient support strength under static pressure, the Young's modulus of the adhesive is as follows: △L=F×h1 / (A×E).

[0046] Repeatedly stacking and applying adhesive, then curing, as follows: Figure 3 As shown, the battery cell is obtained; the battery cell is then assembled into a solid-state battery through assembly processes such as connecting piece welding and vacuum packaging.

[0047] Under high static pressure, the frame and the positive electrode sheet are compressed simultaneously to support the edge of the electrode sheet without breakage, and the battery does not experience a short circuit.

[0048] Example 2 This embodiment provides a method for fabricating a solid-state battery with an electrode frame in a stacking process. The specific steps are as follows: Select die-cut solid-state battery positive electrode sheets and spray insulating adhesive on both sides of the material area at the base of the electrode tab. The thickness of the insulating adhesive is 40μm, and the spraying width is 0.5mm from the edge of the negative electrode sheet to the material area after stacking the positive and negative electrodes, and 2mm in the direction of the positive electrode tab. The length of the sprayed insulating adhesive is to completely cover the material area at the base of the electrode tab. The sprayed insulating adhesive is then cured and dried.

[0049] The positive electrode sheet with insulating adhesive is stacked on top of the negative electrode sheet, and pressure is applied to prevent misalignment. The area of ​​the negative electrode material extending beyond the edge of the positive electrode sheet is the adhesive application area. The edge of the positive electrode sheet is located using visual positioning as the adhesive application path, and adhesive is applied to the adhesive application area on the negative electrode sheet. Adhesive is applied according to the dimensional deviations of the positive and negative electrode sheets and the size of the adhesive application opening until the adhesive area is completely covered, with the adhesive thickness being 1 times the thickness of the positive electrode sheet. The negative electrode sheet is then stacked on top of the adhesive-coated positive electrode sheet, and the surfaces of the upper and lower negative electrode sheets are pressed flat to compact the three sheets. The adhesive is cured using methods such as ultraviolet light and high temperature to fix the positive and negative electrode sheets in place.

[0050] The adhesive used is a UV adhesive. After curing, the linear shrinkage rate of the adhesive is less than 1%. The adhesive does not react chemically with the positive and negative electrode materials. The hardness of the adhesive meets the requirements of D40 to D90. To ensure that the solid-state battery has sufficient support strength under static pressure, the Young's modulus of the adhesive is as follows: △L=F×h1 / (A×E).

[0051] Repeated stacking, coating, and curing of adhesives yields battery cells; these cells then undergo assembly processes such as welding connecting pieces and vacuum sealing to form solid-state batteries.

[0052] Under high static pressure, the frame and the positive electrode sheet are compressed simultaneously to support the edge of the electrode sheet without breakage, and the battery does not experience a short circuit.

[0053] Example 3 This embodiment provides a method for fabricating a solid-state battery with an electrode frame in a stacking process. The specific steps are as follows: Select die-cut solid-state battery positive electrode sheets and spray insulating adhesive on both sides of the material area at the base of the electrode tab. The thickness of the insulating adhesive is 25μm, and the spraying width is 0.4mm from the edge of the negative electrode sheet to the material area after stacking the positive and negative electrodes, and 1mm in the direction of the positive electrode tab. The length of the sprayed insulating adhesive is to completely cover the material area at the base of the electrode tab. The sprayed insulating adhesive is then cured and dried.

[0054] The positive electrode sheet with insulating adhesive is stacked on top of the negative electrode sheet, with an alignment tolerance of no more than 0.3 mm. Pressure is applied to prevent misalignment of the positive and negative electrode sheets. The area of ​​the negative electrode material extending beyond the edge of the positive electrode sheet is the adhesive application area. The edge of the positive electrode sheet is located using visual positioning as the adhesive application path, and adhesive is applied to the adhesive application area on the negative electrode sheet. Adhesive is applied according to the dimensional deviations of the positive and negative electrode sheets and the size of the adhesive application opening until the adhesive area is completely covered. The adhesive thickness is 1.05 times the thickness of the positive electrode sheet. The negative electrode sheet is then stacked on top of the adhesive-coated positive electrode sheet, and the surfaces of the upper and lower negative electrode sheets are pressed flat to compact the three electrode sheets. The adhesive is cured using methods such as ultraviolet light and high temperature to fix the positive and negative electrode sheets relatively in place.

[0055] The adhesive used is a UV adhesive. After curing, the linear shrinkage rate of the adhesive is less than 1%. The adhesive does not react chemically with the positive and negative electrode materials. The hardness of the adhesive meets the requirements of D40 to D90. To ensure that the solid-state battery has sufficient support strength under static pressure, the Young's modulus of the adhesive is as follows: △L=F×h1 / (A×E).

[0056] Repeated stacking, coating, and curing of adhesives yields battery cells; these cells then undergo assembly processes such as welding connecting pieces and vacuum sealing to form solid-state batteries.

[0057] Under high static pressure, the frame and the positive electrode sheet are compressed simultaneously to support the edge of the electrode sheet without breakage, and the battery does not experience a short circuit.

[0058] Comparative Example 1 This comparative example provides a method for preparing a solid-state battery, the specific steps of which are as follows: Select die-cut solid-state battery positive electrode sheets, and spray insulating adhesive on one side of the material area at the root of the electrode tab. The thickness of the insulating adhesive is 10μm, and the spraying width is 0.3mm from the edge of the negative electrode sheet to the material area after the positive and negative electrodes are stacked, and 0.5mm in the direction of the positive electrode tab. The length of the sprayed insulating adhesive is to completely cover the material area at the root of the electrode tab. The sprayed insulating adhesive is then cured and dried.

[0059] The positive electrode sheet with insulating adhesive is stacked on top of the negative electrode sheet, with an alignment error of no more than 0.3 mm. Pressure is applied to prevent misalignment of the positive and negative electrode sheets. The area of ​​the negative electrode material extending beyond the edge of the positive electrode sheet is the adhesive application area. The edge of the positive electrode sheet is located using visual positioning as the adhesive application path, and adhesive is applied to the adhesive application area on the negative electrode sheet. Adhesive is applied according to the dimensional deviations of the positive and negative electrode sheets and the size of the adhesive application opening until the adhesive area is completely covered. The adhesive thickness is 1.1 times the thickness of the positive electrode sheet. The negative electrode sheet is then stacked on top of the adhesive-coated positive electrode sheet, and the surfaces of the upper and lower negative electrode sheets are pressed flat to compact the three electrode sheets. The adhesive is cured using methods such as ultraviolet light and high temperature to fix the positive and negative electrode sheets relatively in place.

[0060] The adhesive used is a UV adhesive. After curing, the linear shrinkage rate of the adhesive is less than 1%. The adhesive does not react chemically with the positive and negative electrode materials. The hardness of the adhesive meets the requirements of D40 to D90. To ensure that the solid-state battery has sufficient support strength under static pressure, the Young's modulus of the adhesive is as follows: △L=F×h1 / (A×E).

[0061] Repeated stacking, coating, and curing of adhesives yields battery cells; these cells then undergo assembly processes such as welding connecting pieces and vacuum sealing to form solid-state batteries.

[0062] Comparative Example 2 This comparative example provides a method for preparing a solid-state battery, the specific steps of which are as follows: Select die-cut solid-state battery positive electrode sheets and spray insulating adhesive on both sides of the material area at the base of the electrode tab. The thickness of the insulating adhesive is 10μm, and the spraying width is 0.3mm from the edge of the negative electrode sheet to the material area after stacking the positive and negative electrodes, and 0.5mm in the direction of the positive electrode tab. The length of the sprayed insulating adhesive is to completely cover the material area at the base of the electrode tab. The sprayed insulating adhesive is then cured and dried.

[0063] The positive electrode sheet with insulating adhesive is stacked on top of the negative electrode sheet, with an alignment error of no more than 0.3 mm. Pressure is applied to prevent misalignment of the positive and negative electrode sheets. The area of ​​the negative electrode material extending beyond the edge of the positive electrode sheet is the adhesive application area. The edge of the positive electrode sheet is located using visual positioning as the adhesive application path, and adhesive is applied to the adhesive application area on the negative electrode sheet. Adhesive is applied according to the dimensional deviations of the positive and negative electrode sheets and the size of the adhesive application opening until the adhesive area is completely covered. The adhesive thickness is 1.1 times the thickness of the positive electrode sheet. The negative electrode sheet is then stacked on top of the adhesive-coated positive electrode sheet, and the surfaces of the upper and lower negative electrode sheets are pressed flat to compact the three electrode sheets. The adhesive is cured using methods such as ultraviolet light and high temperature to fix the positive and negative electrode sheets relatively. Ordinary adhesive is used.

[0064] Repeated stacking, coating, and curing of adhesives yields battery cells; these cells then undergo assembly processes such as welding connecting pieces and vacuum sealing to form solid-state batteries.

[0065] Comparative Example 3 This comparative example provides a conventional method for preparing a solid-state battery, the preparation process of which is as follows: Figure 1 As shown, the specific steps are as follows: S1: Welding: Weld the positive aluminum connecting piece to the positive electrode tab, and weld the negative copper connecting piece to the negative electrode tab. Apply solder sealant to the weld marks.

[0066] S2: Packaging: Use pre-cut aluminum-plastic film to package the battery cell with welded tabs, leaving an opening for drying the battery cell.

[0067] S3: Drying: Place the packaged battery cells into an oven to dry them.

[0068] S4: Vacuum Packaging: The dried cells are vacuum packaged and then precisely cut to form a soft-pack battery.

[0069] S5: Static pressure: The soft-pack battery is placed in an isostatic press and pressurized.

[0070] S6: Formation and Capacity Testing: This test measures the battery's charge-discharge cycle performance.

[0071] The electrical properties of the battery cells obtained in the examples and comparative examples are shown in Table 1: Table 1 shows the electrical performance of the battery cells prepared in the examples and comparative examples.

[0072] As shown in Table 1, the short-circuit rate of the battery increases significantly when only one side of the positive electrode tab is insulated. When the high-hardness or low-hardness rubber frame isostatically compressed or the rubber frame thickness is too high or too low, the compression amount of the rubber frame thickness and the electrode thickness are different, causing displacement of the electrode edge, which increases the short-circuit rate and reduces the cycle performance. Therefore, using double-sided sprayed insulating adhesive can avoid short circuits at the electrode tab root. Selecting an adhesive with appropriate hardness and Young's modulus can effectively support the electrode edge and improve the battery cycle performance.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0074] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a solid-state battery with an electrode and frame in a stacking process, characterized in that, include: The base area of ​​the electrode tab of the die-cut solid battery positive electrode sheet is coated with insulating adhesive on both sides and then cured and dried. The cured and dried positive electrode sheet is stacked on the negative electrode sheet and fixed with pressure. The area of ​​the negative electrode sheet that exceeds the size of the positive electrode sheet is identified as the adhesive coating area. Adhesive is applied along the outer edge of the positive electrode sheet excluding the tab portion. The adhesive coating width is smaller than the deviation size after stacking the positive and negative electrode sheets, and the adhesive coating thickness is greater than the thickness of the positive electrode sheet. The negative electrode sheets are stacked to make the negative electrode sheet and the positive electrode sheet fit tightly together. Adhesive is applied to bond the edges of the two negative electrode sheets and the positive electrode sheet simultaneously. Positive and negative electrode sheets are stacked and cured to obtain a cell, which is then assembled into a battery.

2. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, The conditions for the double-sided spraying of insulating adhesive are as follows: the thickness of the insulating adhesive is 10-40μm, the spraying width is 0.3-0.5mm from the edge of the negative electrode to the material area after the positive and negative electrodes are stacked, and 0.5-2mm in the direction of the positive electrode tab. The spraying length completely covers the material area at the root of the electrode tab.

3. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, The curing and drying process includes heat drying or light drying.

4. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, The alignment error between the positive and negative electrode sheets is no greater than 0.3 mm; the pressure applied after alignment is 300-600 MPa.

5. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, The coating process employs a visual positioning method, using the edge of the positive electrode sheet as the coating trajectory, and the coating thickness is 1-1.1 times the thickness of the positive electrode sheet.

6. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, The curing process includes ultraviolet curing or high-temperature curing.

7. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 1, characterized in that, After curing, the linear shrinkage rate of the adhesive is no greater than 1%; the adhesive does not chemically react with the positive and negative electrode materials; the hardness of the adhesive is D40-D90.

8. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 7, characterized in that, The Young's modulus E of the adhesive satisfies the following relationship: ΔL = F × h1 / (A × E).

9. The method for preparing a solid-state battery with electrode and frame in the stacking process according to claim 8, characterized in that, F is the static pressure, ΔL is the compression of the positive electrode sheet thickness under the specified static pressure, h1 is the coating thickness, and A is the area of ​​the coating frame.

10. A solid-state battery, characterized in that, Prepared using the preparation method described in any one of claims 1-9.

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