Vacuum static pressure bonding method and system for solid-state battery cells

Abstract

This invention discloses a vacuum static pressing method and system for solid-state battery cells, relating to the field of solid-state battery manufacturing technology. The method obtains the material characteristic parameters and pressing constraints of the stacked battery cells; it performs a staged vacuum static pressing process on the stacked cells, including three stages: pre-pressurization and degassing, gradient pressurization and densification, and graded depressurization and shaping. Each stage involves differentiated and coordinated control of vacuum degree, pressure, and temperature; during the pressing process, the cell densification state is monitored in real time and compared with preset targets, and the process parameters are corrected in a closed-loop manner based on the deviation. This invention resolves the contradiction between solid-solid interface densification and low-stress, damage-free operation through staged coordinated control and closed-loop correction, avoiding electrode cracking, electrolyte breakage, and interface springback, improving interface bonding quality and mass production consistency. It is applicable to the vacuum static pressing process of various solid-state battery stacked cells.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery manufacturing technology, and specifically to a vacuum static pressure bonding method and system for solid-state battery stacked cells. Background Technology

[0002] Solid-state batteries, due to their higher energy density and intrinsic safety, are widely recognized as the core development direction of next-generation lithium-ion battery technology and a key focus of current industrialization efforts in the new energy storage field. Unlike liquid lithium-ion batteries, which rely on continuous ion transport channels formed by electrolyte wetting, all-solid-state batteries have a rigid solid-solid contact interface between the positive and negative electrodes and the solid electrolyte. The tightness and uniformity of this interface contact directly determine the cell's interface impedance, ion transport efficiency, and cycle life, making them core factors determining the overall performance of solid-state batteries. Vacuum hydrostatic pressing (including isostatic pressing) is a core process in solid-state battery cell manufacturing to achieve densification of the stacked layers and improve the solid-solid interface contact. Through the coupling effect of pressure and temperature fields in a vacuum environment, it eliminates microscopic gaps between layers and increases the effective contact area of ​​the interface, making it a key process for solving the interface challenges of solid-state batteries.

[0003] Currently, the static isostatic pressing process for solid-state battery cells in the industry largely follows the control logic of traditional cold pressing and hot pressing processes. It generally adopts a basic process of "one-time pressure increase - constant pressure holding - rapid pressure release," coupled with fixed temperature and vacuum settings. This results in crude process control, making it difficult to adapt to the molding requirements of multi-material systems and multi-layer stacked structures in solid-state batteries. Among the published patent technologies, Chinese patent CN114447406B discloses a method for the warm isostatic pressing preparation of all-solid-state cells, clearly defining the basic temperature and pressure parameter ranges for warm isostatic pressing. However, its core solution still uses a one-time pressure increase and holding mode with fixed parameters, failing to set differentiated process control logic for different stages of cell densification. This cannot solve the problems of electrode cracking and electrolyte breakage caused by stress concentration during high-pressure loading, nor does it consider the interface springback defects in the pressure release stage after holding. Chinese patent CN121601803A proposes a two-stage process of pre-pressing + re-pressing for the pressing process of electrode components. The pressing scheme only sets a threshold requirement for the density after pressing, without addressing the coordinated control of pressure, temperature, and vacuum during the pressing process, nor quantifying the differences in thermo-mechanical properties of different material systems. This results in poor process adaptability and an inability to solve the problem of uneven densification of the inner and outer layers of large-capacity stacked cells. Chinese patent CN110112457A discloses a vacuum heating and pressurization preparation method for sulfide all-solid-state batteries, but it only uses low-pressure fixed parameter pressing of 2~5MPa, which can only be adapted to the preparation of small-sized button cells in the laboratory. It cannot meet the densification requirements of large-capacity stacked cells, and the interface bonding effect is limited, making it difficult to achieve industrial application.

[0004] In terms of pressure control, existing processes and publicly available patented solutions generally adopt a constant static pressure holding mode, relying solely on static extrusion to achieve cell densification. Solid electrolyte particles cannot fully fill the microscopic voids at the interface through plastic rheology, resulting in a high residual rate of interfacial micropores, insufficient effective contact area, and consistently high interfacial impedance. Furthermore, existing solutions often employ a one-time direct high-pressure application method, leaving no gradient stress release channel within the stacked cells. This easily leads to defects such as positive electrode coating cracking, brittle electrolyte fragmentation, and interlayer slippage. For example, in the CN114447406B solution, the maximum pressure can reach 700 MPa, significantly increasing the cell breakage rate under ultra-high pressure. After pressure holding, a rapid, instantaneous depressurization method is commonly used. The compressed cell interface undergoes elastic rebound, causing micro-gaps to form again at the previously bonded interface. This defect continues to worsen during cycling, ultimately leading to interfacial delamination and rapid capacity decay.

[0005] In terms of temperature control, existing processes and patented solutions mostly adopt a single, fixed temperature control mode throughout the entire process, without considering the differences in thermorheological properties and thermal stability of different materials such as positive and negative electrodes and solid electrolytes, nor quantifying the differences in thermal inertia between the lamination system and the cell stack. For sulfide solid electrolytes, excessively high temperatures can easily cause material oxidation and decomposition, and binder volatilization and failure, while excessively low temperatures result in insufficient electrolyte plasticity, making effective densification impossible. For oxide solid electrolytes, although higher temperatures are required to improve material plasticity, the fixed temperature mode cannot simultaneously ensure interface formation and material structural stability. At the same time, existing solutions lack gradient heating and cooling control, and drastic temperature changes can lead to mismatches in the thermal expansion and contraction deformation of the electrode and electrolyte, causing cell warping and electrode misalignment. The lamination effect of different batches of cells fluctuates greatly, making it difficult to guarantee mass production consistency.

[0006] In terms of vacuum environment control, existing processes and patented solutions generally employ a control logic with a fixed vacuum level throughout the entire process, which cannot meet the core requirements of different stages of lamination. In the initial pre-bonding stage of lamination, a high vacuum environment is required to fully expel residual gas between layers, preventing gas from forming closed-cell insulation points. However, in the high-voltage densification stage, a continuous high vacuum environment exacerbates the volatilization of the electrode adhesive, damaging the stability of the electrode structure and easily causing oxidative degradation of the sulfide electrolyte. Existing fixed-vacuum solutions consistently fail to balance the core contradiction between "deep venting" and "material protection," resulting in numerous interface defects and degradation of the intrinsic properties of the materials after lamination.

[0007] In terms of mass production adaptability, existing processes and patented solutions are mostly open-loop control modes, lacking a real-time judgment and dynamic adjustment mechanism for the cell densification state during the pressing process. This prevents them from adaptively adjusting process parameters based on fluctuations in incoming cell materials, changes in equipment status, and variations in environmental parameters. Furthermore, most solutions are developed for small-sized button cells in laboratory settings, such as the low-voltage pressing solution of CN110112457A, which cannot adapt to the multi-layered structure of large-capacity laminated cells. This can easily lead to uneven stress distribution and inconsistent temperature distribution between inner and outer layers, resulting in insufficient densification of the inner layer. Additionally, some solutions require significant modifications to existing vacuum static press hardware, leading to high modification costs and difficulties in industrialization, making them unsuitable for direct compatibility with industry-standard mass production equipment.

[0008] In summary, the existing vacuum static pressure bonding process for solid-state battery cells and the publicly available patented solutions cannot resolve the core contradiction between "high interface density" and "low stress and no damage," nor can they meet the core requirements of mass production for process adaptability, batch consistency, and production yield. These have become key technological bottlenecks restricting solid-state batteries from moving from the laboratory to industrial mass production. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a vacuum static pressure bonding method for solid-state battery cells, comprising: The material characteristic parameters and pressing constraints of the laminated battery cell are obtained. The laminated battery cell is composed of a positive electrode, a solid electrolyte layer and a negative electrode stacked together. Based on the material characteristic parameters and pressing constraints, the laminated cells are subjected to a staged vacuum static pressing process. The staged vacuum static pressing process includes a pre-pressurization and degassing stage, a gradient pressurization and compaction stage, and a graded depressurization and shaping stage. The vacuum measurement value, applied pressure value, and operating temperature value of the vacuum chamber are differentially and collaboratively controlled in each stage. During the pressing process, the characterization of the cell compaction state is detected in real time. The characterization is compared with the preset compaction target value. Based on the comparison deviation, the process parameters of the staged vacuum static pressing process are corrected in a closed loop.

[0010] Furthermore, the material characteristic parameters include solid electrolyte type, binder component ratio, electrode coating thickness, and number of stacked layers; the pressing constraints include pressure safety upper limit, solid electrolyte thermal stability temperature upper limit, binder volatilization heat loss temperature, pressure increase upper limit per unit time, and pressure release upper limit per unit time.

[0011] Furthermore, the pre-pressure exhaust stage includes: pumping the vacuum chamber to a first vacuum level and maintaining it, applying a first pressure value to the stacked cells, and controlling the operating temperature within a first temperature range to expel interlayer gas.

[0012] Furthermore, the gradient pressurization compaction stage includes: adjusting the vacuum measurement value of the vacuum chamber from the first vacuum measurement value to the second vacuum measurement value, wherein the first vacuum measurement value is higher than the second vacuum measurement value; under the condition of the second vacuum measurement value, gradually increasing the applied pressure from the first pressure value to the pressure peak value according to a preset pressurization gradient, wherein a pulsating pressure component is superimposed within each pressurization gradient step, and simultaneously gradually increasing the operating temperature from the first temperature range to the temperature peak value according to a preset temperature gradient.

[0013] Furthermore, the pressure peak value is determined based on the solid electrolyte type and the number of laminate layers; the temperature peak value is determined based on the upper limit of the solid electrolyte thermal stability temperature and the binder volatilization heat loss temperature value, and the temperature peak value is simultaneously lower than both the upper limit of the solid electrolyte thermal stability temperature and the binder volatilization heat loss temperature value.

[0014] Furthermore, the stage of graded pressure relief and shaping includes: after maintaining the pressure at the peak temperature and the peak pressure for a preset time, gradually reducing the applied pressure according to the preset pressure relief gradient, and synchronously reducing the working temperature within each pressure relief step, so that the pressure load and temperature load are simultaneously removed along the cooperative path. Furthermore, the characterization quantities of the cell compaction state include the cell thickness reduction, the characteristic value of the pressure-displacement response curve, or the rate of change of interface impedance; the closed-loop correction includes: adjusting the pressurization rate, the amplitude of the pulsating pressure component, or the pressure peak value of the gradient pressurization stage according to the comparison deviation.

[0015] A vacuum static pressure bonding system for solid-state battery cells, used to perform the aforementioned vacuum static pressure bonding method for solid-state battery cells, the system comprising: The parameter acquisition module is used to acquire the material characteristic parameters and pressing constraints of the laminated battery cells; The staged pressing execution module is used to perform staged vacuum static pressing on the laminated cells according to the material characteristic parameters and pressing constraints. The staged vacuum static pressing includes a pre-pressurization and degassing stage, a gradient pressurization and compaction stage, and a graded depressurization and shaping stage. Each stage performs differentiated and coordinated control on the vacuum measurement value, applied pressure value, and working temperature value of the vacuum chamber. The densification detection and correction module is used to detect the characterization quantity of the cell densification state in real time during the pressing process, compare the characterization quantity with the preset densification target value, and perform closed-loop correction of the process parameters of the staged vacuum static pressing process based on the comparison deviation.

[0016] The positive and progressive effects of this invention are as follows: This invention divides the vacuum static pressure bonding process into three differentiated control stages: pre-pressure venting, gradient pressure compaction, and staged pressure relief and shaping. Vacuum, pressure, and temperature are coordinated and adjusted at each stage, completely abandoning the traditional crude method of one-time pressure boosting and holding. The high vacuum and low pressure of the pre-pressure venting stage removes interlayer gas, preventing closed-cell defects. The gradient pressure compaction stage promotes the plastic rheological filling of micro-voids by switching vacuum levels, pulsating pressure superposition, and gradient temperature increases, while avoiding stress concentration-induced damage to the electrode and electrolyte. The staged pressure relief and shaping stage uses synchronous pressure-temperature gradient removal to suppress interfacial elastic rebound and solidify the interfacial bonding state. Based on this, a real-time detection and closed-loop correction mechanism for the cell compaction state is introduced, which can adaptively adjust key parameters such as the boost rate and pulsation amplitude, significantly improving the process's adaptability to different material systems and different stacking layers, ensuring consistency and yield in mass production. This invention effectively solves the core contradiction between solid-solid interface densification and low-stress, damage-free operation, providing reliable process support for solid-state batteries to move from the laboratory to industrial mass production. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the steps of a vacuum static pressure bonding method for solid-state battery cells. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. (Refer to...) Figure 1 The specific embodiments of the present invention will be described in detail below with reference to the claims of the present invention. These embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0019] This embodiment applies to the vacuum static pressure bonding process of all-solid-state lithium battery stacked cells, wherein the stacked cells are composed of multiple layers of positive electrode sheets, solid electrolyte layers, and negative electrode sheets stacked alternately. This embodiment addresses the shortcomings of existing technologies, such as single and crude pressure control, fixed temperature and vacuum levels, severe interface rebound, and lack of real-time closed-loop correction, by providing a fully implementable vacuum static pressure bonding control method for solid-state battery cells.

[0020] A vacuum static pressing method for solid-state battery cells includes: acquiring material characteristic parameters and pressing constraints of the stacked cells; performing a staged vacuum static pressing process on the stacked cells based on the material characteristic parameters and pressing constraints, including a pre-pressure venting stage, a gradient pressure densification stage, and a graded pressure relief and shaping stage, wherein the vacuum measurement value, applied pressure value, and operating temperature value are differentially and collaboratively controlled in each stage; during the pressing process, the characteristic quantity of the cell densification state is detected in real time, the characteristic quantity is compared with a preset densification target value, and the process parameters of the staged vacuum static pressing process are closed-loop corrected based on the comparison deviation.

[0021] Furthermore, the material characteristic parameters and pressing constraints of the laminated battery cell are obtained, specifically including: In one example, the material characteristic parameters are obtained by the host computer through the process formula database, including the solid electrolyte type—which can be classified as sulfide type, oxide type, or composite type according to the material system; the binder component ratio, i.e., the mass percentage of the binder in the solid electrolyte layer; the electrode coating thickness, recording the thickness of the positive electrode coating and the thickness of the negative electrode coating respectively; and the number of laminated layers, i.e., the total number of positive electrode, electrolyte layer, and negative electrode layers. The pressing constraints include the upper limit of pressure safety, determined by the compressive strength of the battery cell structure; the upper limit of the thermal stability temperature of the solid electrolyte, generally not exceeding 180 degrees Celsius for sulfide type and not exceeding 300 degrees Celsius for oxide type, depending on the specific material; the heat loss temperature value of binder volatilization, for example, the long-term temperature resistance of PVDF type binder is about 150 degrees Celsius; the upper limit of pressure increase per unit time to prevent dynamic impact, for example, not exceeding 5 MPa per second; and the upper limit of pressure release per unit time to prevent excessive rebound, for example, not exceeding 3 MPa per second. The above parameters provide a boundary basis for differentiated control in subsequent stages, ensuring that process parameters are set within the material's tolerance limits.

[0022] Furthermore, the specific execution process of the pre-pressure venting stage includes: in one example, evacuating the vacuum chamber containing the stacked battery cells from atmospheric pressure to a first vacuum level, ranging from 0.1 Pa to 10 Pa, and maintaining this vacuum level. Simultaneously, applying a first pressure value to the stacked battery cells using a pressing plate, ranging from 0.5 MPa to 2 MPa, provides sufficient clamping force to initially bond the layers without damaging the electrodes. The operating temperature is controlled within a first temperature range, typically room temperature between 20 and 40 degrees Celsius. During this stage, the high vacuum environment allows air, moisture, and other gases trapped between the positive and negative electrodes and the solid electrolyte layer to escape and be removed, preventing them from forming bubble-like insulation points during the subsequent high-voltage stage. The duration of this stage is set according to the cell size and the number of stacked layers, generally ranging from five to thirty minutes.

[0023] Furthermore, the specific execution process of the gradient pressurization densification stage includes: In one example, after the pre-pressurization and degassing stage is completed, the vacuum measurement value of the vacuum chamber is adjusted from a first vacuum measurement value to a second vacuum measurement value. The absolute pressure of the first vacuum measurement value is lower than that of the second vacuum measurement value, meaning the gas pressure corresponding to the second vacuum measurement value is higher, and its value range is typically from 50 Pa to 500 Pa. Appropriately reducing the vacuum level can slow down the excessive volatilization of the binder and the surface decomposition of the sulfide electrolyte under continuous high vacuum, while still maintaining a certain vacuum environment. Under this second vacuum measurement value condition, the applied pressure is gradually increased from the first pressure value to the pressure peak value according to the preset pressurization gradient. The pressurization gradient can adopt a constant step size method, increasing by 10 MPa to 20 MPa in each step, and maintaining it for a period of time in each step to allow the internal stress of the laminated cell to relax. Within each pressurization gradient step, a pulsating pressure component is superimposed on the current static pressure. The pulsating waveform can be a sine wave or a square wave, with an amplitude of 5% to 15% of the current static pressure and a frequency of 0.1 Hz to 1 Hz. This pulsation promotes the rearrangement and plastic rheology of solid electrolyte particles, further filling the microscopic voids at the interface. Simultaneously, the operating temperature is gradually increased from the first temperature range to the peak temperature according to a preset heating gradient, with a heating rate of, for example, 2 to 5 degrees Celsius per minute. This temperature increase reduces the yield strength of the solid electrolyte, enhancing its densification ability.

[0024] Furthermore, the determination of peak pressure and peak temperature includes the following specific methods: In one example, the peak pressure is determined based on both the type of solid electrolyte and the number of laminate layers. For sulfide solid electrolytes, due to the softness of the material, the peak pressure is typically set between 100 MPa and 300 MPa; for oxide solid electrolytes, the peak pressure needs to be set between 300 MPa and 500 MPa. The more laminate layers there are, the higher the peak pressure required to overcome the contact resistance at each interface can be. The determination of the peak temperature must simultaneously meet two constraints: the peak temperature must be lower than the upper limit of the thermal stability temperature of the solid electrolyte and lower than the heat loss temperature of the binder volatilization. The smaller of the two values ​​is taken, with a safety margin of 10 to 20 degrees Celsius as the peak temperature. In this way, sufficient plasticity of the electrolyte is ensured while preventing thermal decomposition of the material or failure of the binder.

[0025] Furthermore, the specific execution process of the graded depressurization and shaping stage includes: In one example, after the pressure reaches its peak value and the working temperature reaches its peak value, the pressure-temperature state is maintained for a preset duration, typically ten to sixty minutes, to fully solidify the densification state. After the holding period, the graded depressurization stage begins, gradually reducing the applied pressure according to a preset depressurization gradient, for example, reducing by ten to thirty MPa per step, and maintaining each step for two to five minutes; within each depressurization step, the working temperature is simultaneously and gradually reduced at a rate of two to five degrees Celsius per minute, depending on the material characteristics, so that the pressure load and temperature load are simultaneously removed along a coordinated path. Through graded depressurization in coordination with pressure and temperature, the interfacial elastic rebound caused by traditional rapid depressurization can be effectively suppressed, allowing the bonding interface to maintain a tight contact state during the gradual cooling and shrinkage process, avoiding the regeneration of micro-gap and solidifying the interfacial bonding quality.

[0026] Furthermore, the specific implementation of the closed-loop correction mechanism includes: In one example, during the pressing process, especially in the gradient pressurization stage, the characterization parameters of the cell compaction state are detected in real time. These characterization parameters can be: the cell thickness reduction, measured online by a high-precision displacement sensor to measure the change in the total cell thickness; or characteristic values ​​of the pressure-displacement response curve, such as the displacement change rate and the abrupt change point of the curve slope at a certain pressure step; or the interface impedance change rate, measured by in-situ electrochemical impedance spectroscopy to measure the decreasing trend of the interface impedance. The real-time detected characterization parameters are compared with a preset compaction target value, which is calibrated based on previous process experiments. If the actual characterization parameters deviate from the target value, the process parameters of the staged vacuum static pressing process are corrected in a closed-loop manner based on the comparison deviation. Correction methods include: when the compaction rate is insufficient, appropriately increasing the pressurization rate in the gradient pressurization stage, or increasing the amplitude of the pulsating pressure component; when an abnormal inflection point is detected in the pressure-displacement curve indicating a risk of stress concentration, reducing the pressurization rate or lowering the peak pressure. The corrected parameters are fed back to the execution module in real time, enabling adaptive iterative optimization of the process.

[0027] Furthermore, this invention also provides a vacuum static pressing system for solid-state battery cells, used to execute the above-mentioned method. This system includes a parameter acquisition module, a staged pressing execution module, and a densification detection and correction module. The parameter acquisition module acquires material characteristic parameters and pressing constraints through a human-machine interface or manufacturing execution system interface and transmits them to the staged pressing execution module. The staged pressing execution module consists of a vacuum unit, a servo pressure drive mechanism, heating and temperature control components, and a central controller. The central controller outputs given curves for vacuum degree, pressure, and temperature according to the set parameters, in three stages: pre-pressurization and degassing, gradient pressurization and densification, and staged depressurization and shaping. All execution mechanisms operate in coordination. The densification detection and correction module integrates detection devices such as displacement sensors or impedance analyzers to acquire densification state characteristics online. It embeds deviation comparison and parameter adjustment algorithms and feeds correction commands back to the staged pressing execution module in real time, forming a closed-loop control. This system can be directly integrated with a general-purpose industrial vacuum static press without significant hardware modifications, meeting the needs of large-scale mass production.

[0028] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vacuum static pressure bonding method for solid-state battery cells, characterized in that, include: The material characteristic parameters and pressing constraints of the laminated battery cell are obtained. The laminated battery cell is composed of a positive electrode, a solid electrolyte layer and a negative electrode stacked together. Based on the material characteristic parameters and pressing constraints, the laminated cells are subjected to a staged vacuum static pressing process. The staged vacuum static pressing process includes a pre-pressurization and degassing stage, a gradient pressurization and compaction stage, and a graded depressurization and shaping stage. The vacuum measurement value, applied pressure value, and operating temperature value of the vacuum chamber are differentially and collaboratively controlled in each stage. During the pressing process, the characterization of the cell compaction state is detected in real time. The characterization is compared with the preset compaction target value. Based on the comparison deviation, the process parameters of the staged vacuum static pressing process are corrected in a closed loop.

2. The vacuum static pressure bonding method for solid-state battery cells according to claim 1, characterized in that, The material characteristic parameters include solid electrolyte type, binder component ratio, electrode coating thickness, and number of stacked layers; the pressing constraints include pressure safety upper limit, solid electrolyte thermal stability temperature upper limit, binder volatilization heat loss temperature, pressure increase upper limit per unit time, and pressure release upper limit per unit time.

3. The vacuum static pressure bonding method for solid-state battery cells according to claim 1, characterized in that, The pre-pressure exhaust stage includes: pumping the vacuum chamber to a first vacuum level and maintaining it, applying a first pressure value to the stacked cells, and controlling the operating temperature within a first temperature range to expel interlayer gas.

4. The vacuum static pressure bonding method for solid-state battery cells according to claim 3, characterized in that, The gradient pressurization and densification stage includes: adjusting the vacuum measurement value of the vacuum chamber from the first vacuum measurement value to the second vacuum measurement value, wherein the first vacuum measurement value is higher than the second vacuum measurement value; under the condition of the second vacuum measurement value, gradually increasing the applied pressure from the first pressure value to the pressure peak value according to the preset pressurization gradient, with pulsating pressure components superimposed within each pressurization gradient step, and simultaneously gradually increasing the operating temperature from the first temperature range to the temperature peak value according to the preset temperature gradient.

5. The vacuum static pressure bonding method for solid-state battery cells according to claim 4, characterized in that, The pressure peak value is determined based on the solid electrolyte type and the number of laminates; the temperature peak value is determined based on the upper limit of the solid electrolyte thermal stability temperature and the binder volatilization heat loss temperature value, and the temperature peak value is simultaneously lower than both the upper limit of the solid electrolyte thermal stability temperature and the binder volatilization heat loss temperature value.

6. The vacuum static pressure bonding method for solid-state battery cells according to claim 4, characterized in that, The graded depressurization and shaping stage includes: after maintaining the temperature peak and pressure peak conditions for a preset time, gradually reducing the applied pressure according to the preset depressurization gradient, and synchronously reducing the working temperature within each depressurization step, so that the pressure load and temperature load are simultaneously removed along the cooperative path.

7. The vacuum static pressure bonding method for solid-state battery cells according to claim 1, characterized in that, The characterization parameters of the cell compaction state include the cell thickness reduction, the characteristic value of the pressure-displacement response curve, or the rate of change of interface impedance; the closed-loop correction includes adjusting the pressurization rate, the amplitude of the pulsating pressure component, or the pressure peak value of the gradient pressurization stage according to the comparison deviation.

8. A vacuum static pressure bonding system for solid-state battery cells, characterized in that, A vacuum static pressure bonding method for performing any one of claims 1 to 7 of a solid-state battery cell, the system comprising: The parameter acquisition module is used to acquire the material characteristic parameters and pressing constraints of the laminated battery cells; The staged pressing execution module is used to perform staged vacuum static pressing on the laminated cells according to the material characteristic parameters and pressing constraints. The staged vacuum static pressing includes a pre-pressurization and degassing stage, a gradient pressurization and compaction stage, and a graded depressurization and shaping stage. Each stage performs differentiated and coordinated control on the vacuum measurement value, applied pressure value, and working temperature value of the vacuum chamber. The densification detection and correction module is used to detect the characterization quantity of the cell densification state in real time during the pressing process, compare the characterization quantity with the preset densification target value, and perform closed-loop correction of the process parameters of the staged vacuum static pressing process based on the comparison deviation.

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