An ultrathin electronic cigarette battery and a manufacturing process thereof

Abstract

This invention discloses an ultra-thin electronic cigarette cell and its manufacturing process, comprising: placing the cell in a sealed container and evacuating the container; injecting an electrolyte into the sealed container, controlling the temperature of the injected electrolyte to be higher than the initial temperature of the cell, so as to build a surface tension gradient inside the cell; applying a periodically changing dynamic pressure field to the sealed container through a pressure generator, the dynamic pressure field including a pressurization phase and a depressurization phase; during the depressurization phase of the dynamic pressure field, activating an ultrasonic generator to apply ultrasonic vibration to the cell; stopping the application of the dynamic pressure field and ultrasonic vibration, releasing the pressure, and removing the cell. The manufacturing process of this invention utilizes the temperature difference to induce a surface tension gradient to generate a self-adsorption driving force. Simultaneously, by temporally coupling ultrasonic vibration with the depressurization phase of the dynamic pressure field, the low-pressure environment reduces the cavitation threshold, effectively breaking down the gas resistance barrier, significantly improving the wetting efficiency and uniformity of the electrolyte, and shortening the production cycle.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery cell manufacturing technology, and particularly relates to a manufacturing process for an ultra-thin electronic cigarette battery cell. Background Technology

[0002] Currently, e-cigarette cells typically employ a soft-pack square or cylindrical structure. Due to the limited internal space of e-cigarettes, cell designs tend towards ultra-thinness. However, the gap between the electrodes and the separator in ultra-thin cells is extremely small, and the electrode compaction density is high, resulting in high resistance to electrolyte penetration inside the cell and a tendency to form wetting dead zones.

[0003] Traditional electrolyte injection processes mainly rely on natural penetration or vacuum settling, which suffers from long wetting times and poor wetting uniformity, especially for high-viscosity electrolytes, where the wetting effect is even less than ideal. Simple constant-pressure injection is insufficient to effectively solve the air resistance problem within micropores and can easily damage the internal structure of the battery cell.

[0004] In addition, existing impregnation processes also employ a combination of vacuum injection and ultrasonic vibration. This method involves injecting electrolyte after evacuating the internal gas of the battery cell and continuously applying ultrasonic vibration during the injection process to promote electrolyte penetration. However, this method has the following drawbacks: First, under high pressure, the ultrasonic cavitation threshold increases significantly during continuous ultrasonic vibration, making it difficult to generate an effective cavitation effect and wasting a large amount of ultrasonic energy. Second, continuous ultrasonic mechanical vibration under high pressure generates mechanical fatigue stress on the separator material of the ultra-thin battery cell, which can easily lead to damage to the separator's microstructure and cause short circuit risks. Third, for high-viscosity electrolytes, only macroscopic driving through ultrasound and pressure is possible. In the deep micropores, especially in the dead zones where the electrode contacts the separator, the electrolyte penetration rate slows down significantly, resulting in poor impregnation uniformity.

[0005] Therefore, there is an urgent need for an ultra-thin electronic cigarette cell manufacturing process that can improve wetting efficiency, ensure wetting uniformity, and not damage the cell. Summary of the Invention

[0006] The purpose of this invention is to address the problems of low wetting efficiency, poor uniformity, and easy damage to the battery cell in existing technologies. This application proposes a manufacturing process for an ultra-thin electronic cigarette battery cell that utilizes the synergistic effect of temperature difference-induced surface tension gradient combined with the time-sequential coupling of dynamic pressure field and ultrasonic vibration to achieve rapid and uniform wetting of the electrolyte.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A manufacturing process for an ultra-thin electronic cigarette battery cell includes the following steps: The battery cell is placed in a sealed container, and the sealed container is then evacuated. Electrolyte is injected into the sealed container, and the temperature of the injected electrolyte is controlled to be higher than the initial temperature of the battery cell, so as to build a surface tension gradient inside the battery cell. A periodically changing dynamic pressure field is applied to the sealed container by a pressure generator, the dynamic pressure field including a pressurization phase and a depressurization phase; During the depressurization phase of the dynamic pressure field, an ultrasonic generator is activated to apply ultrasonic vibrations to the battery cell. Stop applying the dynamic pressure field and the ultrasonic vibration, release the pressure, and remove the battery cell.

[0008] The above scheme controls the temperature difference between the electrolyte and the battery cell to create a surface tension gradient (Marangoni effect) in the micropores inside the battery cell, generating a self-adsorption driving force to promote the penetration of electrolyte into the pores. At the same time, by coupling ultrasonic vibration with the pressure reduction phase of the dynamic pressure field in a time sequence, the ultrasonic cavitation threshold is reduced by using a low-pressure environment, and a high-intensity micro-jet is generated instantaneously to break through the air resistance. The synergistic effect of the two significantly improves the wetting efficiency and uniformity, and avoids damage to the diaphragm caused by continuous ultrasound.

[0009] Preferably, the temperature difference between the electrolyte temperature and the initial temperature of the battery cell is 15-35℃.

[0010] The above-mentioned preferred solution ensures that the surface tension gradient is large enough to generate an effective driving force by limiting the specific temperature difference range, while avoiding the adverse effects of excessive temperature difference on the performance of the cell material.

[0011] Preferably, one cycle of the dynamic pressure field includes a slow pressurization phase, a high-pressure holding phase, and a rapid depressurization phase; the pressurization rate of the slow pressurization phase is 0.01-0.05 MPa / s, with the highest pressure reaching 0.3-0.5 MPa; the high-pressure holding phase lasts for 2-5 seconds; the depressurization rate of the rapid depressurization phase is greater than 0.2 MPa / s, with the lowest pressure dropping to -0.05 to -0.09 MPa; and the ultrasonic vibration is applied only during the rapid depressurization phase.

[0012] The above-mentioned preferred scheme adopts an asymmetric pressure waveform of "slow pressure and fast extraction" and applies ultrasonic vibration during the rapid decompression stage to achieve "compression and then bursting" of the bubbles, effectively eliminating the air resistance dead zone, while avoiding damage to the diaphragm from continuous ultrasound.

[0013] Preferably, the ultrasonic vibration adopts a frequency sweep mode, in which the ultrasonic frequency gradually decreases linearly from 50kHz to 20kHz as the immersion process time progresses.

[0014] The above-mentioned preferred scheme uses a frequency conversion sweep mode to match the ultrasonic frequency with the gradually increasing acoustic impedance during the cell impregnation process, ensuring the effective transfer of ultrasonic energy and further improving the impregnation effect.

[0015] Preferably, the periodic frequency of the dynamic pressure field is 0.5-2Hz.

[0016] The above-mentioned preferred scheme optimizes the periodic frequency of the pressure field, ensuring that the dynamic pressure field can effectively drive electrolyte penetration without damaging the physical structure of the battery cell.

[0017] Preferably, the power density of the ultrasonic vibration is 0.5-5 W / cm². 2 .

[0018] The above-mentioned preferred scheme ensures the ultrasonic cavitation effect and mechanical vibration effect by setting a reasonable ultrasonic power density, while avoiding damage to the battery cell caused by excessive energy.

[0019] Preferably, the ratio of the depressurization rate in the rapid depressurization phase to the pressurization rate in the slow pressurization phase is greater than 5:1.

[0020] The above-mentioned preferred scheme quantifies the core characteristics of the "slow pressure, fast extraction" asymmetric waveform by limiting the ratio of the depressurization rate to the pressurization rate. A ratio greater than 5:1 means that the pressurization process is slow and gentle, giving the electrolyte sufficient time to penetrate the pores, while the depressurization process is rapid and abrupt. The resulting negative pressure suction and low-pressure environment create optimal conditions for ultrasonic cavitation. The combination of these two factors achieves efficient removal of air resistance and effective protection of the diaphragm.

[0021] Preferably, the electrolyte is a high-viscosity electrolyte with a viscosity range of 100-1000 mPa·s.

[0022] The above-mentioned preferred solution is particularly suitable for high-viscosity electrolytes, solving the problem of poor wetting effect of traditional processes on high-viscosity electrolytes.

[0023] Preferably, the vacuum degree of the vacuuming process is below -0.095MPa, and the holding time is 5-10 minutes; the amount of electrolyte injected is 1.1-1.3 times the theoretical electrolyte absorption capacity of the cell.

[0024] The above-mentioned preferred scheme creates favorable initial conditions for subsequent impregnation processes through pretreatment and liquid injection volume control.

[0025] In addition, the present invention also provides an ultra-thin electronic cigarette cell, which is manufactured by the above-described ultra-thin electronic cigarette cell manufacturing process.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a manufacturing process for an ultra-thin electronic cigarette cell. By controlling the temperature difference between the electrolyte and the cell, a surface tension gradient is constructed within the micropores, generating a self-adsorption driving force, thus solving the problem of insufficient penetration power for high-viscosity electrolytes. By sequentially coupling ultrasonic vibration with the depressurization phase of a dynamic pressure field, the cavitation threshold is lowered using a low-pressure environment, achieving efficient removal of air resistance while avoiding damage to the diaphragm from continuous ultrasound. Variable frequency sweep ultrasound technology is employed to match the acoustic impedance changes during the cell impregnation process, ensuring energy transfer efficiency. In summary, this invention significantly shortens the impregnation time, improves impregnation uniformity, and avoids diaphragm damage, making it suitable for the mass production of ultra-thin electronic cigarette cells. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0029] Example 1

[0030] This embodiment provides a manufacturing process for an ultra-thin electronic cigarette cell. This process solves the problems of low electrolyte wetting efficiency and poor uniformity in the prior art by constructing a surface tension gradient induced by temperature difference and combining the synergistic effect of dynamic pressure field and ultrasonic vibration time-series coupling.

[0031] Step S100: Place the battery cell in a sealed container and evacuate the sealed container.

[0032] Specifically, the sealed container can be a stainless steel pressure vessel or a specially designed autoclave, and the container must have good sealing performance and pressure resistance. Vacuuming aims to pre-emptively remove air from the inside of the battery cell and the container, reducing environmental pressure and creating a negative pressure environment for subsequent electrolyte injection and permeation. Vacuuming effectively reduces the gas content within the micropores of the battery cell, lowering the resistance to electrolyte permeation caused by gas.

[0033] Step S200: Inject electrolyte into a sealed container, and control the temperature of the injected electrolyte to be higher than the initial temperature of the battery cell, so as to build a surface tension gradient inside the battery cell.

[0034] This is one of the core steps of this embodiment. Specifically, this embodiment adopts a "thermal liquid, cold core" electrolyte injection strategy, meaning the injected electrolyte temperature is higher than the initial temperature of the battery cell. When the higher-temperature electrolyte comes into contact with the lower-temperature surface of the battery cell and penetrates into the micropores, a significant temperature gradient exists between the electrolyte at the pore inlet and the depth of the pore. According to physicochemical principles, the surface tension of a liquid decreases as the temperature increases. Therefore, the electrolyte surface tension is lower at the higher-temperature pore inlet and higher at the lower-temperature pore depth. This surface tension gradient induces the Marangoni effect, generating a tangential force from the low surface tension region (hot end) to the high surface tension region (cold end), thereby forming a self-adsorption driving force at the microscale, actively "pulling" the electrolyte into the tiny pores inside the battery cell. This surface tension gradient driving force induced by the temperature difference can effectively overcome the capillary resistance of the high-viscosity electrolyte in narrow pores, significantly improving the wetting efficiency.

[0035] Step S300: A periodically changing dynamic pressure field is applied to the sealed container through a pressure generator. The dynamic pressure field includes a pressurization phase and a depressurization phase.

[0036] Specifically, the pressure generator can be a hydraulic pump, a pneumatic pump, or a servo pressure control system. A dynamic pressure field refers to a physical field where pressure changes periodically over time; its waveform can be a sine wave, square wave, triangular wave, or other irregular waveform. The function of the dynamic pressure field is to create a "compression-expansion" cycle on the air resistance (bubbles) inside the battery cell through periodic pressurization and depressurization processes. During the pressurization phase, the bubbles are compressed, their volume decreases, and electrolyte is forced into the space originally occupied by the bubbles; during the depressurization phase, the bubbles expand, and surrounding electrolyte is drawn in. This repeated "breathing" action effectively breaks up the bubbles, promoting the penetration and distribution of electrolyte between the electrodes and the separator.

[0037] In step S400, during the depressurization phase of the dynamic pressure field, the ultrasonic generator is activated to apply ultrasonic vibration to the battery cell.

[0038] Specifically, the ultrasonic generator converts electrical energy into high-frequency mechanical vibration energy through a transducer, which is then transferred to the battery cell through a medium (such as electrolyte or container wall). When ultrasonic vibration propagates in the liquid, it generates a cavitation effect, where tiny bubbles in the liquid grow, contract, and collapse rapidly under the influence of ultrasonic vibration. The collapse of these bubbles instantly generates localized high temperatures, high pressures, and intense microjets. These microjets possess extremely strong impact force, effectively scouring the electrode surface, breaking down the surface tension barrier between the electrolyte and the electrode material, and forcibly pushing the electrolyte into the deep pores inside the electrode. In this embodiment, ultrasonic vibration and a dynamic pressure field are coupled synergistically: the dynamic pressure field handles the macroscopic "breathing" and exhaust, while ultrasonic vibration handles the microscopic "bursting" and penetration. These two elements complement each other, significantly improving wetting efficiency and uniformity.

[0039] Step S500: Stop applying the dynamic pressure field and ultrasonic vibration, release the pressure and remove the battery cell.

[0040] Specifically, after the preset soaking time is completed, the system automatically stops the operation of the pressure generator and ultrasonic generator. Then, the pressure inside the sealed container is slowly released to atmospheric pressure via a pressure relief valve to prevent a sudden pressure drop from impacting the battery cell structure. Finally, the container is opened, the soaked battery cell is removed, and any remaining electrolyte on the surface is wiped off, completing the entire manufacturing process.

[0041] Through the above scheme, this embodiment utilizes the surface tension gradient induced by temperature difference to generate a microscopic self-adsorption driving force, solving the problem of insufficient penetration power of high viscosity electrolyte; at the same time, combined with the time-series coupling synergistic effect of dynamic pressure field and ultrasonic vibration, it achieves efficient removal of air resistance and deep wetting, significantly shortening the wetting time and improving the wetting uniformity.

[0042] Example 2

[0043] This embodiment, based on Embodiment 1, specifies the temperature difference parameter. Specifically, the temperature difference between the electrolyte temperature and the initial temperature of the battery cell is 15-35℃.

[0044] The selection of temperature difference parameters is crucial for constructing an effective surface tension gradient. If the temperature difference is too small, such as below 15°C, the temperature gradient formed by the electrolyte at the inlet and depth of the cell's micropores is insufficient, resulting in a weak surface tension gradient difference. The self-adsorption driving force generated by the Marangoni effect is weak, making it difficult to effectively overcome the penetration resistance of high-viscosity electrolytes, and the improvement in wetting efficiency is limited. If the temperature difference is too large, such as above 35°C, although the surface tension gradient is significant, the excessively high electrolyte temperature may cause thermal shrinkage and deformation of the membrane material inside the cell, or even trigger the volatilization or decomposition of the electrolyte solvent, affecting the electrochemical performance and safety of the cell.

[0045] In this embodiment, the injected electrolyte temperature is preferably controlled at 45°C, the initial cell temperature at 20°C, and the temperature difference at 25°C. This temperature difference is within the optimal range of 15-35°C, which generates a sufficiently strong Marangoni convection effect, forming a powerful microscopic self-adsorption force to rapidly "pull" the electrolyte into the deep pores of the electrode, while ensuring that the thermal stability of the cell material is not affected. Experimental data shows that when the temperature difference is controlled at 25°C, the electrolyte penetration rate reaches its peak, and the cell's cycle performance remains stable. It should be understood that the specific value of the temperature difference can be appropriately adjusted according to the specific composition of the electrolyte (such as different solvent systems) and the thermal characteristics of the cell material. As long as it is maintained within the range of 15-35°C, a good wetting effect can be obtained.

[0046] Example 3

[0047] This embodiment optimizes the synergistic effect of dynamic pressure field and ultrasonic vibration based on embodiment 2. Specifically, ultrasonic vibration is applied to the battery cell during the depressurization phase of the dynamic pressure field. This design utilizes the temporal coupling effect of the pressure field and ultrasonic vibration; during the depressurization phase, the ambient pressure inside the battery cell decreases rapidly, causing the bubbles to expand. At this time, the solubility of gases inside the liquid decreases, making it easier for bubbles to precipitate and grow. More importantly, as the ambient pressure decreases, the ultrasonic cavitation threshold of the liquid also decreases. Applying ultrasonic vibration under low pressure can induce a strong cavitation effect with lower ultrasonic power, generating transient microjets that instantly break up bubbles and open blocked pore channels, achieving a "low-pressure explosion" effect, thereby significantly improving deep wetting efficiency.

[0048] Furthermore, one cycle of the dynamic pressure field includes a slow pressurization phase, a high-pressure holding phase, and a rapid depressurization phase. The slow pressurization phase has a pressurization rate of 0.01-0.05 MPa / s, with a maximum pressure of 0.3-0.5 MPa; the high-pressure holding phase lasts 2-5 seconds; and the rapid depressurization phase has a depressurization rate greater than 0.2 MPa / s, with a minimum pressure dropping to -0.05 to -0.09 MPa. This embodiment employs an asymmetric waveform design of "slow pressure, rapid depressurization." The slow pressurization phase allows sufficient time for the electrolyte to penetrate the micropores under pressure, while preventing excessively rapid pressure rise that could damage the cell structure; the high-pressure holding phase maintains the pressure to ensure sufficient electrolyte filling; and the rapid depressurization phase utilizes the negative pressure suction generated by the rapid pressure drop to "extract" residual gas from the pores and create an optimal low-pressure environment for ultrasonic cavitation.

[0049] Specifically, the ultrasonic vibration is applied only during the rapid depressurization phase. This phase-locked control strategy is the core of this embodiment. During the slow pressurization and high-pressure holding phases, the internal pressure of the cell is high, the ultrasonic cavitation threshold is high, making it difficult to generate an effective cavitation effect, and continuous ultrasound may cause mechanical fatigue damage to the ultra-thin diaphragm. However, during the rapid depressurization phase, the pressure drops sharply, the cavitation threshold decreases, and applying ultrasound at this time can maximize the use of cavitation energy to clear air resistance. At the same time, due to the short duration of action, diaphragm damage is effectively avoided.

[0050] Furthermore, the ultrasonic vibration employs a frequency-sweeping mode, where the ultrasonic frequency gradually decreases linearly from 50kHz to 20kHz as the immersion process progresses. This design is based on the physical characteristics of acoustic impedance changes during the cell immersion process. In the initial immersion stage, the pores inside the cell are filled with air, resulting in low acoustic impedance. High-frequency ultrasonic waves (such as 50kHz) have short wavelengths and strong penetrating power, making them suitable for agitating the gas. As immersion continues, the electrolyte gradually fills the pores, increasing the overall density and acoustic impedance of the cell. At this point, the frequency automatically decreases to 20kHz, resulting in a longer wavelength and increased amplitude, which is more conducive to promoting the deep penetration of the high-viscosity electrolyte. This dynamic matching mechanism ensures the effective transfer of ultrasonic energy throughout the immersion process.

[0051] This embodiment achieves precise targeting of air resistance and effective protection of the diaphragm through the aforementioned timing coupling and waveform optimization. Experiments show that, compared to the continuous application of ultrasound, this embodiment improves the wetting uniformity by more than 15% and completely eliminates the risk of diaphragm damage.

[0052] Example 4

[0053] Based on Example 3, this embodiment further refines the specific numerical range of the process parameters to demonstrate the applicability of the technical solution of the present invention under different working conditions.

[0054] Specifically, the periodic frequency of the dynamic pressure field is 0.5-2Hz. The selection of the periodic frequency must balance the wetting effect and the safety of the cell structure. In terms of frequency, the periodic variation frequency of 0.5-2Hz can match the resonant frequency of the bubbles inside the cell, producing a better "breathing" effect. For example, when processing electrolytes with low viscosity, a low frequency of 0.5Hz can be used, utilizing a longer pressurization time to promote penetration; while when processing electrolytes with high viscosity, a high frequency of 2Hz can be used, utilizing rapid compression-expansion cycles to break up the bubbles.

[0055] The power density of the ultrasonic vibration is 0.5-5 W / cm². 2 Power density determines the intensity of ultrasonic energy, ranging from 0.5 to 5 W / cm². 2The range of energy required can generate sufficient cavitation effect to break the surface tension barrier, while avoiding electrolyte overheating or diaphragm damage due to excessive energy. For example, for thinner cells, a lower power density can be used in conjunction with the high-frequency band in the frequency sweep mode to achieve gentle and uniform wetting; for thicker cells or cells with higher compaction density, a higher power density can be used in conjunction with the low-frequency band in the frequency sweep mode to enhance deep penetration.

[0056] The ratio of the depressurization rate in the rapid depressurization phase to the pressurization rate in the slow pressurization phase is greater than 5:1. This parameter quantifies the core characteristics of the "slow pressure, fast extraction" asymmetric waveform. A ratio greater than 5:1 means that the pressurization process is slow and gentle, giving the electrolyte sufficient time to penetrate the micropores, while avoiding excessive pressure rise that could damage the cell structure; while the depressurization process is rapid and abrupt, generating negative pressure suction that "extracts" residual gas from the pores, and the rapidly decreasing environmental pressure creates optimal low-pressure conditions for ultrasonic cavitation. For example, when the pressurization rate is selected as 0.02 MPa / s and the depressurization rate as 0.3 MPa / s, the ratio reaches 15:1, at which point the "slow pressure, fast extraction" effect is most significant, and both the wetting uniformity and gas resistance removal efficiency are optimal. It should be understood that the larger the ratio, the more prominent the asymmetric waveform characteristics and the better the wetting effect, but it is necessary to ensure that the depressurization rate does not exceed the equipment's safe depressurization limit.

[0057] The electrolyte is a high-viscosity electrolyte with a viscosity range of 100-1000 mPa·s. Traditional wetting processes are often ineffective for electrolytes with viscosities exceeding 100 mPa·s, resulting in extremely long wetting times and numerous dead zones. This invention effectively solves the penetration problem of high-viscosity electrolytes by combining a temperature-induced surface tension gradient with the synergistic effect of a dynamic pressure field and the temporal coupling of ultrasonic vibration. Experiments show that even with electrolyte viscosities as high as 1000 mPa·s, the process of this invention can still achieve sufficient wetting in a relatively short time. This is due to the additional self-adsorption driving force provided by the Marangoni effect and the effective removal of gas resistance by the temporally coupled physical field.

[0058] The vacuum level during the vacuuming process is below -0.095 MPa, and the holding time is 5-10 minutes. The amount of electrolyte injected is 1.1-1.3 times the theoretical electrolyte absorption capacity of the battery cell. A high vacuum level is crucial for removing the original gas inside the battery cell; the higher the vacuum level, the less residual gas remains, and the lower the subsequent wetting resistance. Holding for 5-10 minutes ensures effective gas removal. Controlling the amount of electrolyte injected requires balancing wetting adequacy with cost. An excess coefficient of 1.1-1.3 times ensures that the electrolyte completely covers the battery cell and fills the pores while avoiding excessive waste of electrolyte. It should be understood that the above parameter ranges represent a preferred embodiment of the present invention. Although they can achieve the objectives of the present invention, their overall wetting effect is slightly inferior to the preferred scheme in Example 3, which uses a specific temperature difference, timing coupling, and frequency conversion sweep.

[0059] Example 5

[0060] Based on Example 1, this embodiment systematically compares the differences in the effects of two dynamic pressure waveforms, sine wave and triangular wave, on the wetting effect for electrolytes of different viscosity grades, in order to reveal the adaptation relationship between waveform selection and electrolyte viscosity.

[0061] The waveform of the dynamic pressure field determines the pressure variation over time, thus affecting the compression-expansion dynamics of bubbles and the distribution of the electrolyte's permeation driving force. Sine wave pressure changes follow a smooth and continuous mathematical function, with gradual transitions in both pressure increase and decrease, lacking steep pressure abrupt changes. This waveform exerts the gentlest mechanical impact on the cell structure, making it particularly suitable for structurally fragile ultra-thin cells. Under sinusoidal wave drive, bubbles undergo slow compression and expansion, and electrolyte permeation in the pores proceeds in a smooth, plugging manner, with a stable permeation path and minimal backflow or disturbance. However, the pressure change rate of a sinusoidal wave is limited. For electrolytes with high viscosity, the instantaneous driving force peak is low, making it difficult to overcome the strong frictional resistance of high-viscosity liquids in narrow pores within a short time.

[0062] The pressure change of a triangular wave exhibits a linear characteristic: during the pressure rise phase, the pressure linearly increases to the peak at a constant rate, and during the pressure drop phase, it similarly linearly decreases at a constant rate. Compared to a sine wave, a triangular wave exhibits an instantaneous switch in the direction of pressure change at the peak inflection point. Although not as drastic as a square wave, it still generates a stronger pressure surge effect than a sine wave. This moderate-intensity pressure surge can induce more significant volumetric oscillations within the bubble. Especially for high-viscosity electrolytes, the additional inertial force generated by the triangular wave at the peak inflection point can compensate for the instantaneous driving force lacking in a sine wave, helping high-viscosity electrolytes overcome the viscous resistance barrier at the pore inlet.

[0063] To verify the above mechanism analysis, this embodiment uses sine and triangular waves as the waveforms of the dynamic pressure field, respectively, and conducts immersion tests under three electrolyte conditions with different viscosities. The test conditions are uniformly as follows: temperature difference controlled at 25℃ (electrolyte temperature 45℃, initial cell temperature 20℃), dynamic pressure field pressure range of 0.1-0.5MPa, frequency of 1Hz, ultrasonic vibration frequency of 35kHz, and power density of 2W / cm². 2 The electrolyte was applied only during the depressurization phase, with a total immersion time of 30 minutes. Three viscosity grades were selected: 100 mPa·s (low viscosity), 500 mPa·s (medium viscosity), and 1000 mPa·s (high viscosity). The test results are shown in Table 1.

[0064] Table 1. Comparison of wetting performance of sine and triangular waves in electrolytes of different viscosities.

[0065]

[0066] The following conclusions can be drawn from the data in Table 1: Under low-viscosity electrolyte (100 mPa·s) conditions, the wetting effect of the sine wave is superior to that of the triangular wave. The wetting uniformity range of the sine wave is 0.04 g, the dead zone ratio is less than 1%, and the initial charge-discharge efficiency reaches 93%, all of which are better than the 0.06 g, 2%, and 91% of the triangular wave. This is because the low-viscosity electrolyte itself has low permeation resistance, and the smooth and gradual pressure drive provided by the sine wave is sufficient to drive the electrolyte to stably penetrate into the pores of each layer without the need for additional instantaneous impact force. At this time, the pressure change at the peak inflection point of the triangular wave introduces a slight disturbance, causing a brief backflow of electrolyte in some pores, resulting in a slight decrease in wetting uniformity.

[0067] Under medium-viscosity electrolyte (500 mPa·s) conditions, the triangular wave begins to show its advantages. The triangular wave exhibits a wettability uniformity range of 0.05 g, a dead zone ratio of less than 1%, and an initial charge-discharge efficiency of 92%, all superior to the sine wave's 0.07 g, 3%, and 90%, respectively. As electrolyte viscosity increases, the driving force peak provided by the smooth, gradual pressure change of the sine wave is insufficient to effectively overcome the frictional resistance of the medium-viscosity electrolyte in deep pores, leading to lag in penetration in some areas and an increase in the dead zone ratio to 3%. The moderate-intensity pressure abrupt change generated at the peak transition point of the triangular wave precisely supplements the required instantaneous driving force, helping the electrolyte overcome the viscous resistance barrier and achieving more uniform deep penetration.

[0068] Under high-viscosity electrolyte (1000 mPa·s) conditions, the advantages of the triangular wave are further amplified. The wetting uniformity range of the sine wave increases to 0.12 g, with a dead zone ratio as high as 8%, and the initial charge-discharge efficiency is only 85%, while the triangular wave still maintains a superior level of 0.06 g, 2%, and 91%. The penetration resistance of high-viscosity electrolyte is extremely high, and the gradual pressure drive of the sine wave can hardly produce effective penetration in deep pores. A large amount of electrolyte remains on the surface of the cell, forming a large area of ​​wetting dead zone in the central region. The triangular wave, with the additional inertial driving force provided by the pressure change at the peak inflection point, combined with the temperature-induced Marangoni effect and the ultrasonic cavitation effect during the pressure reduction stage, overcomes the deep penetration problem of high-viscosity electrolyte in a synergistic manner, maintaining excellent wetting effect.

[0069] It should be understood that the above comparison results reveal the adaptation rule between the selection of dynamic pressure field waveform and electrolyte viscosity: low-viscosity electrolytes are best suited to a smooth sine wave to achieve the gentlest and most uniform wetting effect; medium- and high-viscosity electrolytes are best suited to a triangular wave with moderate pressure abrupt changes to supplement the instantaneous driving force to overcome viscous resistance barriers. The pressure waveforms protected by this invention cover sine curves, square waves, and triangular waves. It is based on this adaptation rule that the process scheme can flexibly meet the wetting requirements of electrolytes with different viscosity grades. In actual production, waveform switching can also be performed according to the stage characteristics of the wetting process. For example, in the early stage of wetting, a triangular wave or square wave can be used to quickly overcome surface resistance, and in the later stage of wetting, a sine wave can be switched for fine and uniform penetration to achieve the optimal wetting effect throughout the entire process.

[0070] Example 6

[0071] Based on Example 3, this embodiment systematically compares the optimization differences of three ultrasonic frequency strategies for wetting effect for electrolytes of different viscosity grades, including low-frequency constant frequency mode (20-30kHz), high-frequency constant frequency mode (40-50kHz), and variable frequency sweep mode (linearly decreasing from 50kHz to 20kHz), to reveal the deep adaptation mechanism between ultrasonic frequency selection and electrolyte viscosity.

[0072] The frequency of ultrasonic vibration directly determines the size distribution of cavitation bubbles and the microjets during collapse, thus affecting the permeation of electrolyte into the micropores of the battery cell. According to ultrasonic cavitation theory, the resonant radius of cavitation bubbles is approximately inversely proportional to the ultrasonic frequency: the lower the frequency, the larger the cavitation bubbles, the stronger the energy released during collapse and the stronger the microjets' impact force, but the lower the bubble density; the higher the frequency, the smaller the cavitation bubbles, the denser and more uniform their distribution, but the weaker the impact force when a single bubble collapses. This physical law determines the differences in the applicability of ultrasound at different frequency bands in different wetting scenarios.

[0073] Large cavitation bubbles generated by low-frequency constant-frequency mode (20-30kHz) can release extremely strong micro-jets upon collapse. This force is sufficient to penetrate the surface tension barrier of the deep contact area between the electrode material and the separator, forcing the electrolyte into the deep pores inside the electrode. However, the distribution density of large cavitation bubbles is low, and the coverage area is limited, potentially leaving blind spots in the micropores of the cell surface. Furthermore, the large amplitude of low-frequency ultrasound results in relatively higher mechanical stress on the ultra-thin separator, requiring strict control of the exposure time to avoid damage.

[0074] The dense and uniform distribution of small cavitation bubbles generated by the high-frequency constant-frequency mode (40-50kHz) can form a fully covered cavitation network in the surface layer and shallow pores of the battery cell, effectively breaking the surface tension barrier of the electrode surface and promoting the uniform distribution of electrolyte in the shallow region. However, the micro-jet impact force when small bubbles collapse is relatively weak and it is difficult to penetrate the resistance barrier of deep pores. For ultra-thin battery cells with high compaction density and tortuous pore paths, the deep penetration capability of high-frequency ultrasound is significantly insufficient.

[0075] The frequency sweep mode (linearly decreasing from 50kHz to 20kHz) cleverly combines the advantages of the two modes mentioned above. In the initial immersion stage, the cell's internal pores are heavily filled with gas, resulting in low acoustic impedance. At this point, high-frequency ultrasound at 50kHz is used to rapidly establish an immersion front in the surface area using dense, small cavitation bubbles, breaking down surface tension barriers and opening channels for subsequent deeper penetration. As immersion progresses, the electrolyte gradually fills the pores, increasing the overall cell density and acoustic impedance. At this point, the frequency is automatically reduced to 20kHz, and the strong micro-jet impact force generated by the large cavitation bubbles effectively propels the electrolyte, which has already penetrated the shallow layers, to continue penetrating deeper. This dynamic frequency matching ensures that the ultrasonic energy remains synchronized with the acoustic characteristics inside the cell throughout the immersion process, avoiding energy waste or insufficient penetration problems that can occur with a single-frequency mode at specific immersion stages.

[0076] To verify the above mechanism analysis, this embodiment employs three ultrasonic frequency strategies—low-frequency constant-frequency mode (25kHz), high-frequency constant-frequency mode (45kHz), and variable-frequency sweep mode (50kHz→20kHz)—to conduct immersion tests under three electrolyte viscosities. The test conditions are uniformly as follows: temperature difference controlled at 25℃, dynamic pressure field using the "slow pressure, fast extraction" asymmetric waveform from Example 3, ultrasonic waves applied only during the rapid pressure release phase, and a power density of 3W / cm². 2 The total immersion time was 20 minutes. Three electrolyte viscosities were selected: 100 mPa·s, 500 mPa·s, and 1000 mPa·s. The test results are shown in Table 2.

[0077] Table 2 Comparison of wetting performance of three ultrasonic frequency strategies in electrolytes of different viscosities

[0078]

[0079] The following conclusions can be drawn from the data in Table 2: Under low-viscosity electrolyte (100 mPa·s) conditions, the wetting effects of the high-frequency constant-frequency mode and the variable-frequency sweep mode are comparable and superior to those of the low-frequency constant-frequency mode. The wetting uniformity range for both the high-frequency (45kHz) and variable-frequency sweep modes is 0.03g, the dead zone ratio is less than 1%, and the initial charge-discharge efficiency is 93%, significantly better than the 0.07g, 3%, and 89% for the low-frequency (25kHz) mode. The low-viscosity electrolyte itself has low penetration resistance; the main challenge in wetting is not deep penetration, but rather uniform coverage of the surface area. The dense, small cavitation bubbles generated by high-frequency ultrasound can fully cover the cell surface, effectively eliminating shallow wetting blind zones and achieving uniform distribution. While low-frequency ultrasound has strong micro-jet impact force, the sparse bubble distribution leads to excessive deep penetration and insufficient surface coverage under low-viscosity conditions, resulting in decreased uniformity. The variable-frequency sweep mode starts with high frequency in the initial wetting stage, perfectly matching the wetting requirement of low-viscosity electrolytes, which prioritizes uniform surface coverage; therefore, its effect is comparable to the pure high-frequency mode.

[0080] Under medium-viscosity electrolyte (500 mPa·s) conditions, the variable frequency sweep mode began to show significant advantages. The wetting uniformity range of the variable frequency sweep mode was 0.04 g, the dead zone ratio was less than 1%, and the initial charge-discharge efficiency was 92%, all significantly better than the 0.08 g, 4%, and 88% of the low-frequency (25 kHz) mode, and far superior to the 0.12 g, 9%, and 84% of the high-frequency (45 kHz) mode. Wetting of medium-viscosity electrolytes requires balancing both surface coverage and deep penetration. While the low-frequency mode has strong deep penetration, insufficient surface coverage leads to wetting lag in the edge areas; while the high-frequency mode provides uniform surface coverage, insufficient deep penetration results in a 9% dead zone in the central area. The variable frequency sweep mode, through dynamic frequency adjustment, ensures uniform surface coverage with high frequency in the initial wetting stage, and then gradually reduces the frequency to enhance deep penetration, achieving an optimal balance between the two dimensions.

[0081] Under high-viscosity electrolyte (1000 mPa·s) conditions, the variable frequency sweep mode exhibits the most significant advantages. The wetting uniformity variation of the variable frequency sweep mode is only 0.05 g, the dead zone ratio is 1%, and the initial charge / discharge efficiency is 91%, while the variations at low frequency (25 kHz) are 0.09 g, 5%, and 87%, respectively, and at high frequency (45 kHz), they are 0.18 g, 15%, and 78%, respectively. High-viscosity electrolytes have extremely high penetration resistance, requiring very high efficiency in the utilization of ultrasonic energy during the wetting process. Although the low-frequency mode has strong single-impact force, the sparse bubble distribution results in a large amount of ultrasonic energy not being effectively utilized, and the large amplitude causes a 3% damage rate to the diaphragm. The micro-jets of the high-frequency mode are almost unable to produce effective deep penetration under high-viscosity conditions, and the 15% dead zone ratio indicates that most of the central area of ​​the cell is not wetted. The frequency conversion sweep mode ensures that ultrasonic energy is used efficiently in every infiltration stage through dynamic matching of frequency and acoustic impedance: high frequency covers the surface in the early stage, transition frequency takes into account the middle layer in the middle stage, and low frequency penetrates the deep layer in the later stage. The energy utilization rate is the highest throughout the process, and the diaphragm damage rate is controlled below 0.5%.

[0082] Of particular note are the differences in diaphragm damage rates. In the low-frequency constant-frequency mode, the diaphragm damage rate increases with electrolyte viscosity (1.5%→2%→3%). This is because high-viscosity electrolytes require longer ultrasonic treatment times to achieve the same wettability, and the large amplitude of low-frequency ultrasound over a long period causes cumulative mechanical fatigue in the ultra-thin diaphragm. In the high-frequency constant-frequency mode, the diaphragm damage rate is 0%, but its wetting effect is severely insufficient under high viscosity conditions. In the variable-frequency sweep mode, the diaphragm damage rate is controlled below 0.5% under all viscosity conditions. This is because the variable-frequency sweep is applied only during the rapid depressurization phase and the frequency is dynamically matched, avoiding the long-term, large-amplitude damage of low-frequency ultrasound while ensuring sufficient effective cavitation energy through frequency variation, achieving optimal wetting effect and diaphragm safety.

[0083] It should be understood that the above comparison results reveal a deep adaptation mechanism between ultrasonic frequency strategies and electrolyte viscosity: low-viscosity electrolytes primarily face the challenge of uniform surface coverage, which can be effectively addressed by either high-frequency or variable-frequency sweep modes; medium- and high-viscosity electrolytes require a balance between surface coverage and deep penetration, and the variable-frequency sweep mode achieves an optimal balance between these two dimensions through dynamic frequency variation, making it the best ultrasonic strategy for addressing the wetting challenges of high-viscosity electrolytes. The ultrasonic frequency range (20-50kHz) and variable-frequency sweep mode protected by this invention are based on this adaptation mechanism, enabling the process scheme to flexibly adapt to the wetting requirements of electrolytes with different viscosity grades. In actual production, the start and end frequencies and variation rates of the variable-frequency sweep can be fine-tuned according to the specific structural parameters of the battery cell (such as thickness, compaction density, and separator material) to achieve the optimal wetting effect for specific products.

[0084] Comparative Example 1

[0085] This comparative example provides a manufacturing process for an ultra-thin electronic cigarette cell, which differs from Example 1 in that a temperature difference between the electrolyte and the cell is not constructed.

[0086] Specifically, in step S200, the temperature of the injected electrolyte is controlled to be consistent with the initial temperature of the battery cell, which is 25°C. The process parameters of the remaining steps S100, S300, S400, and S500 are the same as those in Example 1, that is, the same periodically changing dynamic pressure field and ultrasonic vibration are applied.

[0087] In this comparative scheme, because the electrolyte temperature is the same as the cell temperature, a temperature gradient cannot be formed within the micropores of the cell, thus preventing the construction of a surface tension gradient. This means the lack of the microscopic self-adsorption driving force generated by the Marangoni effect. For high-viscosity electrolytes, capillary forces are inherently weak. In the absence of additional driving forces, the electrolyte can only permeate through the temporal coupling effect of dynamic pressure fields and ultrasonic vibrations. Although the physical field can provide some macroscopic driving force, the permeation rate of the electrolyte slows down significantly in the depths of the micropores, especially in the dead zone region where the electrode and the separator contact, and it is difficult to overcome air resistance.

[0088] Test results show that, without temperature-induced degradation, the wetting time of the battery cell is significantly prolonged, with the time required to achieve the same level of wetting increasing by approximately 40% compared to Example 1. Simultaneously, the electrolyte distribution in the central region of the battery cell is significantly lower than that in the edge regions, resulting in decreased wetting uniformity. This demonstrates that the surface tension gradient induced by temperature difference is a key method for addressing the difficulty of penetrating high-viscosity electrolytes and improving wetting efficiency, and that its temporal coupling with dynamic pressure fields and ultrasonic vibration has a synergistic effect.

[0089] Comparative Example 2

[0090] This comparative example provides a manufacturing process for an ultra-thin electronic cigarette cell, which differs from Example 3 in that ultrasonic vibration is continuously applied throughout the entire cycle of the dynamic pressure field, rather than only during the depressurization phase.

[0091] Specifically, in step S300, a periodically changing dynamic pressure field is applied to the sealed container via a pressure generator. One cycle of this dynamic pressure field also includes a slow pressurization phase, a high-pressure holding phase, and a rapid depressurization phase. Simultaneously, in step S400, an ultrasonic generator is activated to apply ultrasonic vibration to the battery cell. This ultrasonic vibration persists throughout the entire cycle of the dynamic pressure field, meaning it is continuously applied during the slow pressurization phase, the high-pressure holding phase, and the rapid depressurization phase. Other process parameters, such as temperature difference control, pressure waveform parameters, ultrasonic frequency, and power density, remain consistent with those in Example 3.

[0092] In this comparative scheme, due to the continuous action of ultrasonic vibration during the high-pressure phase (slow pressurization phase and high-pressure holding phase) of the dynamic pressure field, the internal environmental pressure of the battery cell is high, and the ultrasonic cavitation threshold of the liquid is significantly increased. To maintain the cavitation effect and promote wetting, higher ultrasonic power is often required, which not only wastes energy but, more seriously, causes continuous mechanical fatigue stress on the separator material of the ultra-thin battery cell due to ultrasonic mechanical vibration under high pressure. Especially during the high-pressure holding phase, the separator is under pressure, and continuous ultrasonic vibration easily leads to damage to the separator's microstructure, such as pore collapse or fiber breakage. During the rapid depressurization phase, although the reduced environmental pressure is conducive to cavitation, the separator is already damaged due to the continuous action of the preceding phases, and the average distribution of ultrasonic energy throughout the cycle results in insufficient energy density during the critical low-pressure burst phase, failing to effectively remove deep gas resistance.

[0093] Test results showed that, under a dissecting microscope, approximately 15% of the cells prepared in Comparative Example 2 exhibited visible microcracks or perforations on the surface of the separator, leading to a significant increase in the short-circuit rate during subsequent formation processes. Simultaneously, because ineffective ultrasound during the high-voltage stage consumed most of the energy, the effective cavitation energy used to break up bubbles was reduced, resulting in a higher proportion of wetting dead zones in the central region of the cell compared to Example 3 (approximately 8%). Wetting uniformity tests indicated that the extreme difference in electrolyte content across different parts of the cell reached 0.15 g, significantly higher than the 0.05 g in Example 3. This demonstrates that the time-coupling strategy of "applying ultrasound only during the depressurization stage" employed in this invention, by precisely matching the low-pressure environment with the ultrasonic cavitation effect, achieves efficient removal of air resistance while effectively avoiding mechanical damage to the separator from continuous ultrasound. This is a key technical means to ensure cell safety and wetting quality.

[0094] To more intuitively illustrate the differences between Embodiment 3 of the present invention and Comparative Example 2, a detailed comparative analysis is provided below using Table 3: Table 3 Performance test comparison between Example 3 and Comparative Example 2

[0095]

[0096] In summary, the test data from Comparative Example 2 fully demonstrates the necessity of the "temporal coupling" feature in this invention. Simple continuous ultrasound not only fails to achieve the optimal wetting effect but also causes irreversible damage to key components of the battery cell, highlighting the inventiveness and practical value of the technical solution of this invention.

[0097] Comparative Example 3

[0098] This comparative example provides a manufacturing process for an ultra-thin electronic cigarette cell, which differs from Example 1 in that only vacuuming and liquid injection are performed, without applying a dynamic pressure field or ultrasonic vibration.

[0099] Specifically, in step S100, the battery cell is placed in a sealed container, and the container is evacuated. The vacuum level and holding time are the same as in Example 1. Subsequently, in step S200, electrolyte is injected into the sealed container, and the temperature of the injected electrolyte is controlled to be higher than the initial temperature of the battery cell, maintaining the same temperature difference conditions as in Example 1. After injection, the dynamic pressure field application in step S300 and the ultrasonic vibration application in step S400 are not performed. Instead, the sealed container is left to stand, relying on the vacuum negative pressure and the surface tension gradient induced by the temperature difference for natural wetting. The standing time is extended to 120 minutes to ensure that the electrolyte penetrates the battery cell as much as possible.

[0100] In this comparative scheme, although a microscopic surface tension gradient was constructed through temperature difference induction, generating a certain self-adsorption driving force, the wetting process mainly relied on passive diffusion due to the lack of the temporal coupling synergy between the dynamic pressure field and ultrasonic vibration. The absence of a dynamic pressure field means that the cell lacks a macroscopic "breathing" effect, making it impossible to compress and expand the air resistance through periodic pressure changes, resulting in difficulty in expelling bubbles. The absence of ultrasonic vibration means that the micro-jets generated by cavitation cannot break the surface tension barrier between the electrode material and the electrolyte, nor can they shatter tiny bubbles. For ultra-thin cells, the internal pores are narrow and the paths are tortuous, making it difficult to overcome deep penetration resistance by relying solely on the microscopic Marangoni effect, especially in the central region of the cell, where wetting dead zones are easily formed.

[0101] Test results showed that the cell prepared in Comparative Example 3 required a wetting time of up to 120 minutes, more than twice that of Example 1. More seriously, CT scans revealed a significant wetting dead zone in the central region of the cell, indicating extremely uneven electrolyte distribution. Dissection revealed that the active material in the center of the electrode was whitish, indicating insufficient electrolyte wetting. Electrochemical performance tests showed that the initial charge-discharge efficiency of this cell was 5% lower than that of Example 1, and the capacity retention rate decreased significantly after 50 cycles. This demonstrates that the temporal coupling and synergistic effect of dynamic pressure field and ultrasonic vibration is indispensable; efficient and uniform wetting of ultra-thin cells cannot be achieved solely through temperature difference induction. This invention achieves a significant improvement in technical performance through active physical field intervention.

[0102] To more intuitively illustrate the differences between Embodiment 1 and Comparative Example 3, a detailed comparative analysis is provided below using Table 4: Table 4 Performance test comparison between Example 1 and Comparative Example 3

[0103]

[0104] In summary, the test data of Comparative Example 3 fully demonstrates the necessity of the temporal coupling and synergistic effect of dynamic pressure field and ultrasonic vibration in this invention. Without active physical field intervention, relying solely on temperature difference induction cannot solve the problem of deep wetting of ultra-thin battery cells, highlighting the completeness and advancement of the technical solution of this invention.

[0105] Application Examples: This embodiment applies the ultra-thin electronic cigarette cell manufacturing process provided by the present invention to a mass production line of a certain type of electronic cigarette cell to verify its actual effect in industrial production.

[0106] Specifically, the 403030 pouch cell was selected for production. This cell is only 4mm thick, making it a typical ultra-thin cell, and its electrode compaction density is as high as 3.6g / cm³. 3 It has extremely low internal porosity, making wetting difficult. The production line is equipped with a fully automated vacuum liquid injection machine, a high-precision pressure control system, and an ultrasonic generator.

[0107] Step S100: Place the battery cell in a sealed container and evacuate the container. The production line adopts a multi-station rotary table structure, with each station independently controlling the vacuum level. The vacuum level is set to -0.098MPa and maintained for 8 minutes to ensure that the gas inside the battery cell is effectively discharged.

[0108] In step S200, electrolyte is injected into a sealed container, with the temperature of the injected electrolyte controlled to be higher than the initial temperature of the battery cell, in order to build a surface tension gradient inside the battery cell. The electrolyte uses a high-viscosity formulation with a viscosity of 500 mPa·s. The preheating temperature is controlled at 45°C, and the initial temperature of the battery cell is controlled at 20°C, with a temperature difference of 25°C. This temperature difference setting effectively induces the Marangoni effect, providing a microscopic self-adsorption driving force for the high-viscosity electrolyte.

[0109] In step S300, a periodically changing dynamic pressure field is applied to the sealed container using a pressure generator. The preferred "slow pressure, fast depressurization" asymmetric waveform from Example 3 is used. During the slow pressurization phase, the pressure increase rate is 0.02 MPa / s, reaching a maximum pressure of 0.4 MPa; the high-pressure holding phase lasts for 3 seconds; and during the rapid depressurization phase, the pressure decrease rate is 0.3 MPa / s, with the minimum pressure dropping to -0.08 MPa.

[0110] Step S400: Start the ultrasonic generator to apply ultrasonic vibration to the battery cell. The ultrasonic vibration is applied only during the rapid depressurization phase, and a frequency sweep mode is used, with the frequency linearly decreasing from 50kHz to 20kHz, and the power density set to 3W / cm². 2 This time-coupling strategy utilizes the reduced ultrasonic cavitation threshold under low-pressure conditions to achieve efficient removal of air resistance while avoiding damage to the diaphragm from continuous ultrasound.

[0111] In step S500, the dynamic pressure field and ultrasonic vibration are stopped, the pressure is released, and the battery cell is removed. The entire immersion cycle is controlled within 15 minutes, which is significantly shorter than the 120 minutes of the traditional process.

[0112] After a month of trial production, the following production data were obtained: the production line operated stably, with the average production cycle time shortened to 15 minutes per batch, resulting in an 87.5% increase in production efficiency; the first-time electrolyte filling pass rate of the battery cells reached 99.2%, an improvement of 4.5 percentage points compared to traditional processes; random sampling tests showed that the uniformity of electrolyte wetting (measured by the range of electrolyte content) was controlled within 0.05g, the initial charge-discharge efficiency remained stable above 92%, and the capacity retention rate after 100 cycles was above 94%. No diaphragm damage or short circuits were found.

[0113] The above application data fully demonstrates that the manufacturing process provided by this invention can perfectly adapt to the large-scale mass production needs of ultra-thin electronic cigarette cells. While ensuring the consistency of cell quality, it significantly improves production efficiency and reduces production costs, and has extremely high industrial application value.

[0114] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A manufacturing process for an ultra-thin electronic cigarette battery cell, characterized in that, Includes the following steps: The battery cell is placed in a sealed container, and the sealed container is then evacuated. Electrolyte is injected into the sealed container, and the temperature of the injected electrolyte is controlled to be higher than the initial temperature of the battery cell, so as to build a surface tension gradient inside the battery cell. A periodically changing dynamic pressure field is applied to the sealed container by a pressure generator, the dynamic pressure field including a pressurization phase and a depressurization phase; During the depressurization phase of the dynamic pressure field, an ultrasonic generator is activated to apply ultrasonic vibrations to the battery cell. Stop applying the dynamic pressure field and the ultrasonic vibration, release the pressure, and remove the battery cell.

2. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 1, characterized in that, The temperature difference between the electrolyte temperature and the initial temperature of the battery cell is 15-35℃.

3. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 2, characterized in that, One cycle of the dynamic pressure field includes a slow pressurization phase, a high-pressure holding phase, and a rapid pressure release phase. The pressurization rate during the slow pressurization phase is 0.01-0.05 MPa / s, with a maximum pressure of 0.3-0.5 MPa. The high-pressure holding phase lasts for 2-5 seconds; The pressure reduction rate during the rapid depressurization phase is greater than 0.2 MPa / s, and the minimum pressure drops to -0.05 to -0.09 MPa. The ultrasonic vibration is applied only during the rapid decompression phase.

4. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 3, characterized in that, The ultrasonic vibration adopts a frequency sweep mode, and as the immersion process time progresses, the ultrasonic frequency gradually decreases linearly from 50kHz to 20kHz.

5. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 3, characterized in that, The periodic frequency of the dynamic pressure field is 0.5-2Hz.

6. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 4, characterized in that, The power density of the ultrasonic vibration is 0.5-5 W / cm². 2 .

7. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 3, characterized in that, The ratio of the depressurization rate during the rapid depressurization phase to the pressurization rate during the slow pressurization phase is greater than 5:

1.

8. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 1, characterized in that, The electrolyte is a high-viscosity electrolyte with a viscosity range of 100-1000 mPa·s.

9. The manufacturing process of an ultra-thin electronic cigarette cell according to claim 1, characterized in that, The vacuum degree of the vacuuming process is below -0.095MPa, and the holding time is 5-10 minutes; the amount of electrolyte injected is 1.1-1.3 times the theoretical electrolyte absorption capacity of the cell.

10. An ultra-thin electronic cigarette battery cell, characterized in that: It is manufactured by the ultra-thin electronic cigarette cell manufacturing process according to any one of claims 1 to 9.

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