High-safety sodium ion battery energy conversion method based on solid electrolyte

Abstract

The invention relates to the technical field of solid-state battery energy conversion, and discloses a high-safety sodium-ion battery energy conversion method based on a solid-state electrolyte, which comprises the following steps: identifying an interface dynamic mismatch risk time period in a charging and discharging process, and applying micro-amplitude high-frequency acoustic vibration disturbance to a solid-state electrolyte and a sodium negative electrode interface in the time period, sodium ion microscopic distribution is regulated and controlled through the acoustic streaming effect, contact stress is dredged, dendritic crystal early nucleation is inhibited, dynamic reconstruction and optimization of the interface state are achieved, the solid-state sodium-electricity interface is converted into dynamic self-adaption from static mismatch, the ion transmission uniformity is actively maintained through the acoustic streaming effect, and dynamic reconstruction and optimization of the interface state are achieved. And meanwhile, real-time sensing of an interface state and dynamic adjustment of acoustic vibration parameters are realized in combination with an acoustic probing mechanism, so that the interface stability and dendritic crystal inhibition capability are effectively improved, and the energy conversion efficiency and the safety performance of the battery are remarkably enhanced.

Description

Technical Field

[0001] The present invention relates to a high-safety sodium ion battery energy conversion method based on a solid electrolyte, belonging to the technical field of solid-state battery energy conversion. Background Art

[0002] Solid-state sodium-ion batteries (SIBs) show great promise in large-scale energy storage due to their high safety and resource abundance. Their energy conversion efficiency and safety are highly dependent on the dynamic stability of the interface between the solid electrolyte (SSE) and the sodium negative electrode. Current technical routes generally focus on improving the static density and intrinsic ionic conductivity of SSE, blocking dendrites through rigid physical barriers, and maintaining ion transmission channels.

[0003] However, during the actual charge and discharge process of the battery, the repeated deposition / stripping behavior of sodium metal causes continuous volume changes and local stress concentration at the interface, resulting in some fundamental contradictions in the traditional static interface design. For example: 1. The non-uniform migration of sodium ions will produce local stress points that are difficult to eliminate at the SSE / sodium negative electrode interface, inducing microscopic contact failure and irreversible growth of interface impedance. This process is particularly significant under harsh working conditions such as fast charging or low temperature. Existing technologies use external mechanical pressure or flexible buffer layers to try to relieve stress, but it is difficult to match the spatiotemporal scale of the dynamic change of the interface, and instead increases 1. The existing scheme relies on the mechanical strength of SSE to passively block dendrite penetration, but cannot interfere with the early nucleation and preferential growth of dendrites at interface defects. When the local current density suddenly increases due to contact failure, the dendrites can still break through the physical barrier along the weak stress points, causing the risk of internal short circuit in the battery. 2. The degradation of solid-state interfaces is usually cumulative and hidden, and the industry's judgment on the health status of the interface mostly relies on macroscopic electrical signals such as voltage and internal resistance. It is difficult to capture key failure precursors such as microscopic contact loss or early dendrite sprouting, resulting in serious lag in protective measures.

[0004] Although recent research has attempted to improve compatibility through composite electrolyte design or interface modification, these improvements have not yet broken through the static interface paradigm and failed to establish the interface's ability to autonomously adjust to dynamic changes. Therefore, the technical challenge addressed by this invention is how to establish a dynamic adaptive mechanism for the solid electrolyte / sodium anode interface to proactively maintain ion transport uniformity and mitigate failure risks during battery charge and discharge. Summary of the Invention

[0005] The present invention provides a high-safety sodium ion battery energy conversion method based on solid-state electrolytes, the main purpose of which is to solve the problems of dendrite growth and impedance increase caused by interface stress mismatch during the dynamic charge and discharge process of solid-state sodium batteries.

[0006] To achieve the above objectives, the present invention provides a high-safety sodium ion battery energy conversion method based on solid electrolyte, the method comprising the following steps:

[0007] Step a, identifying specific interface dynamic mismatch risk periods during the charge and discharge process of the sodium ion battery, where the identification of the periods is based on the dynamic change rate of the battery current, voltage or interface impedance;

[0008] Step b, applying controllable micro-amplitude high-frequency acoustic perturbation to the interface region between the solid electrolyte and the sodium negative electrode during a specific interface dynamic mismatch risk period, wherein the acoustic perturbation generates an acoustic streaming effect in the interface region, thereby regulating the microscopic distribution of sodium ions at the interface, channeling the local contact stress generated by volume change at the interface, and inhibiting the early nucleation and local aggregation of sodium dendrites;

[0009] Step c: Through the acoustic streaming effect, the migration path of sodium ions in the interface region between the solid electrolyte and the sodium negative electrode is continuously and adaptively induced to be redistributed, and the microstructure of the interface atoms or ions is caused to rearrange under the action of local stress, thereby forming a stable state of the interface contact morphology to adapt to the interface stress changes during the charge and discharge cycle.

[0010] Preferably, identifying a specific interface dynamic mismatch risk period in step a includes: when the absolute value of the charging current or discharging current of the sodium ion battery exceeds a preset first current threshold, or when the interface impedance change rate of the battery exceeds a preset second impedance change rate threshold, determining it as a specific interface dynamic mismatch risk period.

[0011] Preferably, applying controllable micro-amplitude high-frequency acoustic disturbance in step b includes: before the application of the acoustic disturbance or during its interval, a preset acoustic probe signal is emitted to the interface area by an acoustic vibration generating unit or an independent acoustic probe unit; the acoustic echo characteristics formed after the interaction between the acoustic probe signal and the interface area are captured and qualitatively analyzed by an acoustic pickup unit, and the acoustic echo characteristics include attenuation degree of a specific frequency, abnormal harmonic components or at least one of phase delay; and according to the instantaneous state of the interface indicated by the acoustic echo characteristics, at least one parameter of the micro-amplitude high-frequency acoustic disturbance is dynamically adjusted, and the parameter is selected from a combination of frequency, amplitude, waveform, action duration or application mode to achieve instant adaptive control of the interface state.

[0012] Preferably, the application of controllable micro-amplitude high-frequency acoustic disturbance in step b is achieved by any of the following methods: the acoustic disturbance is derived from the mechanical vibration or acoustic signal endogenous to the sodium ion battery under specific electrochemical reaction conditions, and the acoustic resonance structure of the battery's current collector or solid electrolyte is designed to utilize or amplify the endogenous vibration; or, the acoustic disturbance is generated on demand by a micro-acoustic device integrated inside or outside the sodium ion battery and acoustically coupled to the sodium negative electrode current collector or solid electrolyte under the control of the battery management system.

[0013] Preferably, the micro-acoustic vibration device is a piezoelectric ceramic thin layer or a magnetostrictive film, and the micro-acoustic vibration device is integrated on the surface of the sodium negative electrode current collector by screen printing or sputtering process; the frequency range of the micro-amplitude high-frequency acoustic vibration disturbance is 1 kHz to 10 MHz, and the amplitude range is 1 nanometer to 10 microns.

[0014] Preferably, the inhibition of early nucleation and local aggregation of sodium dendrites specifically includes: slightly disturbing the ion concentration field and electric field distribution near the tip of the sodium dendrite through the acoustic streaming effect, thereby weakening its preferential growth advantage; or promoting the re-spreading or flattening of the already formed tiny, loose sodium deposits on the interface to prevent their evolution into destructive dendrites.

[0015] Preferably, the relief of interface contact stress includes: micro-amplitude high-frequency acoustic vibration disturbance provides additional micro kinetic energy to interface atoms or ions, promotes their local rearrangement under stress and diffusion of stress points, thereby avoiding stress concentration leading to the initiation of interface microcracks.

[0016] Preferably, the acoustic streaming effect makes the interface impedance show the characteristics of being stable or self-repairing in stages in long-term cycles, and the stability coefficient S of the interface impedance is Z satisfy:

[0017]

[0018] Where ΔZ c is the interface impedance increment under cycle number c, ΔZ0 is the initial interface impedance increment, and α is the preset interface impedance stability threshold percentage. The lower the stability coefficient, the better the stability of the interface impedance.

[0019] Preferably, the solid electrolyte comprises at least one polymer component that is sensitive to acoustic vibration disturbances or a composite solid electrolyte having a specific pore structure, wherein the polymer component or the specific pore structure is designed so that its acoustic impedance forms a match with the sodium negative electrode or current collector that is conducive to the effective transmission of acoustic energy.

[0020] Preferably, it also includes performing the following interface health diagnosis steps at a preset life cycle node of the sodium ion battery: Step 1, driving the acoustic vibration generating unit or the independent acoustic probe unit to generate a swept frequency acoustic excitation or a multi-frequency acoustic pulse sequence covering a preset frequency range in the interface area; Step 2, capturing and processing the acoustic response of the interface area to the swept frequency acoustic excitation or the multi-frequency acoustic pulse sequence through the acoustic pickup unit to generate an acoustic resonance characteristic spectrum or fingerprint data characterizing the current interface state, the acoustic resonance characteristic spectrum or fingerprint data including at least one of the position of the main resonance peak, the relative intensity or peak width of the resonance peak, and the relative change of the average acoustic absorption or reflection coefficient in a specific frequency band; Step 3, comparing and analyzing the currently generated acoustic resonance characteristic spectrum or fingerprint data with historical data to identify the evolution trend of the acoustic resonance characteristic spectrum or fingerprint data; Step 4, based on the evolution trend, evaluating the long-term health status of the interface, predicting its remaining service life, or triggering early warning maintenance instructions.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By applying a small-amplitude high-frequency acoustic vibration disturbance at the interface area to induce a controllable acoustic streaming effect, the problem of dynamic stress accumulation at the rigid interface of traditional solid-state batteries during the repeated deposition and stripping of sodium metal is circumvented. The acoustic streaming effect promotes the uniform distribution of sodium ions at the interface on a microscopic scale, while at the same time channeling the local contact stress generated by volume change, transforming the interface that was originally prone to contact degradation and microcracks into an adaptive interface that can continuously maintain or actively restore a good contact state through tiny dynamic rearrangements at the ionic and atomic levels. This transition from passive stress bearing to active stress channeling effectively improves the structural stability of the interface in long-term cycles, laying a physical foundation for efficient and stable chemical energy-to-electrical energy conversion.

[0023] 2. Different from the hard-hitting strategy of existing technologies that mainly rely on the mechanical strength of materials to block dendrites, the present invention uses the perturbation effect of the acoustic streaming effect on the local ion concentration field and electric field of the interface, effectively weakening the preferential growth trend of the sodium dendrite tip and promoting the re-spreading or flattening of tiny, loose deposits in the dendrite budding stage. This mechanism of active intervention in the initial morphological evolution of sodium deposition eliminates it before the dendrite forms a destructive structure, significantly reducing the risk of internal short circuit or thermal runaway caused by dendrite penetration. To achieve the above-mentioned intervention effect, the method also applies the process of acoustic vibration disturbance to establish the function of real-time perception of the interface state; By emitting specific acoustic probe signals to the interface before or during the application of the main acoustic vibration disturbance, and capturing and analyzing the acoustic reverberation characteristics formed after the signal interacts with the interface, such as specific frequency attenuation, abnormal harmonics, phase delay, etc., the system can qualitatively identify the instantaneous abnormal state of the interface. Based on this diagnostic information, the system then dynamically adjusts the subsequently applied acoustic vibration parameters (frequency, amplitude, waveform, action duration or mode) to perform more targeted acoustic flow activation processing on the specific problems identified. This closed loop of probe perception-feature analysis-parameter adjustment upgrades interface maintenance from a preset general mode to adaptive and precise control based on the actual state.

[0024] 3. At a preset life cycle node, the method further utilizes its acoustic system to apply an acoustic excitation signal covering a specific frequency range to the interface area, such as a frequency sweep or multi-frequency pulse. By capturing and processing the acoustic response of the interface area to this excitation, an acoustic resonance characteristic spectrum or fingerprint data is generated to characterize the current interface state, such as the relative changes in the main resonance peak position, intensity, peak width, or absorption / reflection coefficient in a specific frequency band. Tracking the evolution trend of these characteristic spectra or fingerprint data with the number of cycles or time can provide non-invasive insights into the deep-level material properties of the interface, such as the slow cumulative changes in equivalent stiffness, damping characteristics, and microstructure, providing data support for subsequent judgment of the evolution trend of the interface operating state, estimation of its service life limit, and timely issuance of maintenance warnings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a timing diagram of intelligent perception and parameter adaptive closed-loop control of interface acoustic vibration regulation of solid-state sodium batteries of the present invention;

[0026] Figure 2 Schematic diagram of the interface structure reconstruction and stabilization mechanism of solid-state sodium batteries under the control of acoustic vibration disturbance of the present invention;

[0027] Figure 3 This is a curve diagram of the interface impedance increment changing with the number of cycles of the present invention.

[0028] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0029] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] The present invention provides a high-safety sodium ion battery energy conversion method based on a solid electrolyte, the method comprising the following steps:

[0031] Step a, identifying specific interface dynamic mismatch risk periods during the charge and discharge process of the sodium ion battery, where the identification of the periods is based on the dynamic change rate of the battery current, voltage or interface impedance;

[0032] Step b, applying controllable micro-amplitude high-frequency acoustic perturbation to the interface region between the solid electrolyte and the sodium negative electrode during a specific interface dynamic mismatch risk period, wherein the acoustic perturbation generates an acoustic streaming effect in the interface region, thereby regulating the microscopic distribution of sodium ions at the interface, channeling the local contact stress generated by volume change at the interface, and inhibiting the early nucleation and local aggregation of sodium dendrites;

[0033] Step c: Through the acoustic streaming effect, the migration path of sodium ions in the interface region between the solid electrolyte and the sodium negative electrode is continuously and adaptively induced to be redistributed, and the microstructure of the interface atoms or ions is caused to rearrange under the action of local stress, thereby forming a stable state of the interface contact morphology to adapt to the interface stress changes during the charge and discharge cycle.

[0034] Preferably, identifying a specific interface dynamic mismatch risk period in step a includes: when the absolute value of the charging current or discharging current of the sodium ion battery exceeds a preset first current threshold, or when the interface impedance change rate of the battery exceeds a preset second impedance change rate threshold, determining it as a specific interface dynamic mismatch risk period.

[0035] Preferably, applying controllable micro-amplitude high-frequency acoustic disturbance in step b includes: before the application of the acoustic disturbance or during its interval, a preset acoustic probe signal is emitted to the interface area by an acoustic vibration generating unit or an independent acoustic probe unit; the acoustic echo characteristics formed after the interaction between the acoustic probe signal and the interface area are captured and qualitatively analyzed by an acoustic pickup unit, and the acoustic echo characteristics include attenuation degree of a specific frequency, abnormal harmonic components or at least one of phase delay; and according to the instantaneous state of the interface indicated by the acoustic echo characteristics, at least one parameter of the micro-amplitude high-frequency acoustic disturbance is dynamically adjusted, and the parameter is selected from a combination of frequency, amplitude, waveform, action duration or application mode to achieve instant adaptive control of the interface state.

[0036] Preferably, the application of controllable micro-amplitude high-frequency acoustic disturbance in step b is achieved by any of the following methods: the acoustic disturbance is derived from the mechanical vibration or acoustic signal endogenous to the sodium ion battery under specific electrochemical reaction conditions, and the acoustic resonance structure of the battery's current collector or solid electrolyte is designed to utilize or amplify the endogenous vibration; or, the acoustic disturbance is generated on demand by a micro-acoustic device integrated inside or outside the sodium ion battery and acoustically coupled to the sodium negative electrode current collector or solid electrolyte under the control of the battery management system.

[0037] Preferably, the micro-acoustic vibration device is a piezoelectric ceramic thin layer or a magnetostrictive film, and the micro-acoustic vibration device is integrated on the surface of the sodium negative electrode current collector by screen printing or sputtering process; the frequency range of the micro-amplitude high-frequency acoustic vibration disturbance is 1 kHz to 10 MHz, and the amplitude range is 1 nanometer to 10 microns.

[0038] Preferably, the inhibition of early nucleation and local aggregation of sodium dendrites specifically includes: slightly disturbing the ion concentration field and electric field distribution near the tip of the sodium dendrite through the acoustic streaming effect, thereby weakening its preferential growth advantage; or promoting the re-spreading or flattening of the already formed tiny, loose sodium deposits on the interface to prevent their evolution into destructive dendrites.

[0039] Preferably, the relief of interface contact stress includes: micro-amplitude high-frequency acoustic vibration disturbance provides additional micro kinetic energy to interface atoms or ions, promotes their local rearrangement under stress and diffusion of stress points, thereby avoiding stress concentration leading to the initiation of interface microcracks.

[0040] Preferably, the acoustic streaming effect makes the interface impedance show the characteristics of being stable or self-repairing in stages in long-term cycles, and the stability coefficient S of the interface impedance is Z satisfy:

[0041]

[0042] Where ΔZ c is the interface impedance increment under cycle number c, ΔZ0 is the initial interface impedance increment, and α is the preset interface impedance stability threshold percentage. The lower the stability coefficient, the better the stability of the interface impedance.

[0043] Preferably, the solid electrolyte comprises at least one polymer component that is sensitive to acoustic vibration disturbances or a composite solid electrolyte having a specific pore structure, wherein the polymer component or the specific pore structure is designed so that its acoustic impedance forms a match with the sodium negative electrode or current collector that is conducive to the effective transmission of acoustic energy.

[0044] Preferably, it also includes performing the following interface health diagnosis steps at a preset life cycle node of the sodium ion battery: Step 1, driving the acoustic vibration generating unit or the independent acoustic probe unit to generate a swept frequency acoustic excitation or a multi-frequency acoustic pulse sequence covering a preset frequency range in the interface area; Step 2, capturing and processing the acoustic response of the interface area to the swept frequency acoustic excitation or the multi-frequency acoustic pulse sequence through the acoustic pickup unit to generate an acoustic resonance characteristic spectrum or fingerprint data characterizing the current interface state, the acoustic resonance characteristic spectrum or fingerprint data including at least one of the position of the main resonance peak, the relative intensity or peak width of the resonance peak, and the relative change of the average acoustic absorption or reflection coefficient in a specific frequency band; Step 3, comparing and analyzing the currently generated acoustic resonance characteristic spectrum or fingerprint data with historical data to identify the evolution trend of the acoustic resonance characteristic spectrum or fingerprint data; Step 4, based on the evolution trend, evaluating the long-term health status of the interface, predicting its remaining service life, or triggering early warning maintenance instructions.

[0045] In the specific implementation process, the setting of parameters can be calibrated according to the historical data of the battery operation status and the actual test results, and the evaluation index of the interface stability performance is also comprehensively judged in combination with the multi-dimensional impedance change trend. The acoustic flow effect and the acoustic vibration disturbance mechanism are derived from the micro-scale stress disturbance and ion distribution adjustment behavior caused by the propagation of sound waves in the interface structure. They are all extended implementation methods known to ordinary technicians in this field, and the acoustic vibration disturbance can come from the structural micro-vibration naturally generated during the internal working process of the battery, or it can be actively applied by designing a micro-acoustic vibration device integrated inside or outside the battery. The two methods can be used separately or according to the battery. The two operating conditions are used in conjunction to enhance the flexibility and coverage of acoustic flow control. Under normal circumstances, when the battery has obvious electrochemical endogenous vibration characteristics, the acoustic response generated by its own structure can be used first to achieve interface perturbation without additional energy consumption; in scenarios where the vibration signal is weak or the perturbation parameters need to be precisely controlled, it is appropriate to use external micro-devices for active intervention. The two methods can reserve interfaces in parallel in the system structure design, complement each other, and improve overall adaptability. In addition, the acoustic flow effect mainly refers to the micro-scale material rearrangement phenomenon caused by acoustic vibration perturbation at the interface between the solid electrolyte and the sodium negative electrode, including the migration of sodium ions in the interface area. The redistribution of paths, release and homogenization of contact stress, reconstruction of local microstructure and other aspects, their joint action can effectively weaken the local dendrite growth trend and promote the formation and maintenance of stable interface morphology. It is a dynamic interface regulation process under the coordination of multiple factors. For the evaluation of the long-term operation state of the interface, for example, a judgment method based on the impedance change trend can be adopted, where the initial state can be understood as the interface reference state after the battery has undergone the first stable cycle. The impedance change amplitude corresponding to each subsequent specific number of cycles will be compared with the reference state to measure the degree of fluctuation of interface stability. In practical applications, this change trend can be used as The observation basis of the interface regulation effect and life evolution trend is used to assist subsequent system maintenance judgment; and the stable state of the interface contact morphology refers to the state in which, under the action of the acoustic streaming effect, the interface area between the solid electrolyte and the sodium negative electrode undergoes the redistribution of the microscopic ion migration path and the local rearrangement of atoms / ions, and the interface does not show significant morphological mutations, abnormal impedance growth or microcrack concentration and other failure signs during multiple charge and discharge cycles. This state is usually manifested as a relatively uniform sodium ion migration path, local stress is relieved, and the interface impedance change trend slows down or staged self-repair, etc., all of which are expansion methods known to ordinary technicians in this field.

[0046] Example 1: The present invention proposes a high-safety sodium ion battery energy conversion method based on solid electrolyte, which aims to achieve a synergistic improvement in energy conversion efficiency and safety performance by actively regulating the interface state between the solid electrolyte and the sodium negative electrode. The technical core of this method is to introduce controllable micro-amplitude high-frequency acoustic vibration perturbations. By stimulating the acoustic streaming effect, the interface maintains the uniformity of ion migration under dynamic conditions and suppresses the early failure mechanism, thereby achieving adaptive reconstruction of the interface structure and functional optimization. In the specific implementation process, first, by real-time monitoring of the battery's operating parameters, a specific interface dynamic mismatch risk period during the charging and discharging process is identified. This identification can be judged based on the dynamic change rate of the current, voltage or interface impedance of the sodium ion battery. Specifically, when the absolute value of the battery's charging or discharging current exceeds a preset first current threshold, or when the interface impedance change rate exceeds a second impedance change rate threshold, it is considered to have entered the risk period. Accurate identification of this stage provides a basis for the subsequent on-demand application of acoustic vibration perturbations. During the above-mentioned specific risk period, the present invention applies controllable micro-amplitude high-frequency acoustic vibration perturbations to the interface region between the solid electrolyte and the sodium negative electrode. The disturbance stimulates the acoustic streaming effect, thereby regulating the local distribution of sodium ions at the microscopic level, alleviating the contact stress concentration caused by the volume change caused by the deposition / stripping of sodium metal, and effectively inhibiting the early nucleation and aggregation tendency of sodium dendrites. Compared with the existing mechanical blocking method through rigid barriers, the acoustic streaming effect of the present invention is more proactive and sustainable in achieving dendrite control and stress relief; the implementation methods of acoustic vibration disturbance include the following two methods: one is to use the mechanical vibration signal endogenous to the sodium ion battery under specific electrochemical reaction conditions, combined with a specific current collector structure or solid electrolyte The first method is to amplify the acoustic resonance design of the mass and act on the interface area; the second method is to generate external disturbances through a micro-acoustic vibration device integrated inside or outside the battery, and the device forms an acoustic coupling relationship with the sodium negative electrode current collector or solid electrolyte in structure; the preferred micro-acoustic vibration device is a piezoelectric ceramic thin layer or a magnetostrictive film, which can be integrated on the surface of the sodium negative electrode current collector by screen printing or sputtering process. The frequency range of the disturbance is 1 kHz to 10 MHz, and the amplitude range is controlled between 1 nanometer and 10 microns to ensure that a moderate acoustic streaming effect is stimulated without damaging the interface structure.

[0047] During the disturbance process, in order to realize the real-time perception and response control of the interface state, the system transmits a preset acoustic probe signal to the interface area through the acoustic vibration device or an independent acoustic probe unit before or during the acoustic vibration action, and the acoustic pickup unit collects the acoustic reverberation characteristics after its interaction with the interface. The characteristics may include any one or more of the attenuation degree of a specific frequency, abnormal harmonic components or phase delay. According to the instantaneous state of the interface indicated by the analyzed acoustic reverberation characteristics, the key parameters of the subsequent acoustic vibration disturbance, such as frequency, amplitude, waveform, action duration or application mode, are dynamically adjusted, thereby forming a closed-loop control mechanism to realize the immediacy and pertinence of interface control. In terms of dendrite suppression, the acoustic streaming effect is achieved by slightly disturbing the tip of the sodium dendrite. The ion concentration field and local electric field distribution nearby are adjusted, thereby weakening its preferential growth trend; or the already formed tiny, loose sodium deposits are prompted to spread or flatten on the interface, effectively blocking their evolution into destructive dendrites. This process suppresses the potential initiation of sodium dendrites at an early stage, significantly reducing the probability of internal short circuit and thermal runaway. In addition, the acoustic streaming effect also has a positive impact on the long-term stability of the interface impedance. During multiple charge and discharge cycles, the acoustic streaming perturbation causes the interface impedance to show a tendency to stabilize or stage self-repair. For this reason, the present invention introduces a quantitative indicator of the interface impedance stability coefficient SZ, which is defined as the percentage of the ratio of the difference between the interface impedance increment and the initial increment under a certain cycle number c to the initial increment, and the expression is: When the obtained value is less than or equal to the preset interface impedance stability threshold α, it is considered to have reached a stable state. This indicator provides a quantitative evaluation standard for the implementation effect of the present invention and can be used as a basis for optimizing the interface maintenance strategy.

[0048] In terms of battery life cycle management, the present invention further sets up an interface health diagnosis operation at a predetermined node, and the specific steps include: first, driving the acoustic vibration generating unit or the acoustic probe unit to apply a swept frequency acoustic excitation or a multi-frequency acoustic pulse covering a preset frequency range to the interface area; then, the acoustic response of the area to the excitation is collected by the acoustic pickup unit to generate an acoustic resonance characteristic spectrum or fingerprint data characterizing the current interface state, which includes any item in the position, relative intensity, peak width and relative change of the acoustic absorption or reflection coefficient in a specific frequency band of the main resonance peak; finally, the current data is compared with the historical characteristic spectrum, and its evolution trend is analyzed, so as to evaluate the long-term health status of the interface, predict its remaining life or trigger a maintenance warning instruction; finally, in order to enhance the effect of the acoustic streaming effect in the interface area, the preferred solid electrolyte of the present invention contains a polymer component that is sensitive to acoustic vibration disturbances or a composite solid electrolyte material with a specific pore structure, and the structural design The acoustic impedance of the sodium anode or current collector is matched with the conditions required for acoustic energy transfer, thereby further improving the synergy and response efficiency of interface regulation; and in the implementation of this method, the acoustic streaming effect does not act in isolation on the contact interface between the electrode and the electrolyte, but is triggered by the acoustic vibration disturbance. Through the continuous influence on the local stress field and ion migration behavior, the chain response and gradual evolution of the interface structure are realized. This effect shows a repeatable stable trend under different temperatures, current densities and working cycles. Through multiple groups of working condition tests under typical operating conditions, it is found that after the acoustic vibration disturbance is applied, the migration state of sodium ions on the interface gradually shifts from the initial uneven concentration to diffusion equilibrium, the local deposition area becomes more uniform, the interface contact morphology tends to be flat, and the electrochemical impedance growth rate is significantly reduced. These phenomena indicate that under the action of acoustic streaming, the interface state is indeed dynamically optimized and maintained in a steady state, providing a physical basis for achieving long-term and efficient energy conversion.

[0049] Example 2: This embodiment aims to solve the problem of dynamic mismatch between the solid electrolyte and the sodium negative electrode interface that may occur during the charge and discharge process of solid-state sodium-ion batteries, and proposes an interface state optimization method that integrates acoustic drive control and closed-loop response mechanism. By establishing a closed-loop control path of real-time identification of interface state - acoustic vibration perturbation activation - dynamic parameter control - cyclic adaptive evolution, dynamic reconstruction of the interface structure state and improvement of functional stability are achieved; this solution is constructed around three parts: an interface state identification unit, an acoustic vibration control unit, and an acoustic feedback analysis unit. The three operate in coordination, as follows: The first stage is the identification of the risk of dynamic interface mismatch, the core of which is to judge in real time the risk of dynamic interface mismatch during the operation of the sodium-ion battery. Whether it has entered a critical period that may induce uneven interface ion migration, local stress accumulation or contact degradation. To this end, this embodiment selects the rate of change of current, voltage and interface impedance as the basis for judgment. When the absolute value of the battery's charging or discharging current exceeds a preset current threshold, which is derived from the conversion result of the maximum ion deposition rate allowed for the sodium negative electrode during system design, or when the rate of change of the interface impedance exceeds a set impedance change rate threshold, which is set based on the normal fluctuation range and empirical tolerance during system operation, the system determines that it is currently in a period of risk of dynamic interface mismatch. This judgment is completed in real time by the operation monitoring module in the battery management system and serves as the triggering basis for subsequent acoustic vibration control.

[0050] The second stage is the acoustic vibration disturbance activation process, the goal of which is to stimulate the interface area to form an acoustic flow effect by applying external or structural endogenous micro-high-frequency disturbances, thereby achieving the regulation of the local distribution of sodium ions and the effective guidance of the interface contact stress. The disturbance is achieved in the following two ways: First, an integrated micro-acoustic vibration device is used to actively apply disturbances. The acoustic vibration device is preferably a piezoelectric ceramic thin layer, which is integrated on the surface of the sodium negative electrode current collector by screen printing. The thickness is controlled within tens of microns to take into account both structural stability and acoustic coupling effects. The device works under the control of the battery management system and generates a micro-acoustic vibration signal with a frequency of 1 kHz to 10 MHz and an amplitude of 1 nanometer to 10 microns. The waveform can be selected as a sine wave, square wave or Frequency-amplitude modulated composite waves are used to adapt to the control requirements of different interface states. The frequency and amplitude range are determined based on a large amount of experimental data and engineering experience, and can effectively stimulate the required acoustic streaming effect without causing interface damage. Secondly, the intrinsic vibration signal of the structure is combined with the acoustic resonance structure for amplification and directionality. When the sodium-ion battery itself generates weak mechanical vibrations under specific electrochemical reaction conditions, the acoustic tuning design of the current collector or solid electrolyte structure is performed to form an acoustic resonance area at a specific frequency, thereby enhancing the intensity of the vibration at the interface. The structural design includes directional control of the porosity of the solid electrolyte, optimization of the acoustic wave reflection path of the geometric structure, and matching and coordination of the acoustic impedance of the material.

[0051] The third stage is the establishment of acoustic detection and adaptive control mechanism. In order to realize closed-loop control of interface state, the system transmits acoustic probe signal of preset frequency to the interface area through acoustic vibration device or special probe unit before applying acoustic vibration disturbance or during its interval. At the same time, the acoustic pickup module receives the response of the interface area to the signal and extracts the acoustic echo characteristics. Typical acoustic echo characteristics include the attenuation amplitude of high-frequency components, the enhancement degree of abnormal harmonic components and the phase delay of the response signal. The system's built-in signal processing module performs real-time analysis and pattern recognition on the above acoustic characteristics to determine whether the current interface has problems such as sodium dendrite initiation, uneven charge migration or Contact abnormality and other risk states. Once the above abnormal states are identified, the control module immediately calls the preset parameter optimization strategy or self-learning model to dynamically adjust the parameter combination of the current acoustic vibration disturbance, including frequency, amplitude, waveform, action duration and application rhythm, to ensure that the acoustic streaming effect can act accurately and efficiently on the mismatch area, forming a targeted interface intervention control. In order to further evaluate the effect of the intervention measures in the long-term cycle process, the interface impedance stability coefficient is introduced as a performance evaluation index in the embodiment. This index is defined as the ratio of the interface impedance increment under a certain number of cycles to the impedance increment of the initial state multiplied by a percentage, and is specifically expressed as: where ΔZ c is the interface impedance increment at the cth cycle, ΔZ0 is the impedance increment in the initial state, and when the stability coefficient is less than or equal to the set threshold α, the interface state is considered to have reached a stable state. This indicator can not only be used as a quantitative evaluation standard for the interface regulation effect, but also provide data support for the formulation of subsequent maintenance strategies for the system; in addition, in order to improve the efficiency of acoustic energy in the interface area, the solid electrolyte selected in this embodiment is a polymer component that has response characteristics to acoustic disturbances, or a composite electrolyte material with a specific pore structure. The structural design of this type of material helps to form a matching relationship between its acoustic impedance and the sodium negative electrode or current collector, enhance the efficiency of acoustic energy transfer, expand the scope of acoustic streaming effect, and improve the response speed and execution depth of dynamic interface regulation.

[0052] Example 3: This example combines Figures 1 to 2 , a high-safety sodium-ion battery energy conversion method based on solid electrolyte is described. Figure 1As shown in the figure, after entering the diagnosis stage - dynamic mismatch risk (or early stage of state instability), the battery management system identifies the risk and issues an instruction to start the acoustic probe signal. The interface perception and diagnosis unit activates the high-precision acoustic probe signal and performs multi-dimensional echo feature extraction. The extracted features include: high-frequency harmonic components, specific frequency attenuation, phase delay and abnormal band response. By analyzing at least one feature, the optimal intervention strategy for the current state of the interface is determined; then, the parameter strategy and model library return the dynamically optimized parameter parameter combination. The combination parameters may include frequency, amplitude, waveform, action duration, and application mode. The acoustic vibration execution and control unit executes customized acoustic vibration disturbance, that is, adds precisely controlled acoustic vibration disturbance; after entering the real-time feedback and stability confirmation stage, the interface perception and diagnosis unit continuously monitors low-energy disturbances, returns real-time state parameters, evaluates whether the interface state is stable, and reports to the battery management system whether the interface state has returned to stability or continues abnormal warning monitoring.

[0053] like Figure 2 As shown, first, the piezoelectric film generates high-frequency vibrations under the control of the battery management system. The vibration acts on the interface area, causing a 1-nanometer displacement, so that the interface atoms or ions obtain additional tiny kinetic energy, thereby achieving stress release and inhibiting preferential growth, and further promoting concentration field regulation to improve the interface structure. The regulation of the interface area also depends on the redistribution of ion transport channels guided by acoustic flow. The uniform distribution of sodium ions is achieved in the solid electrolyte through acoustic flow guidance. On the other hand, in the sodium deposition layer, the acoustic vibration disturbance disturbs the dendrite budding stage, prompting the dendrite bud microstructure to undergo microstructural reconstruction, thereby interrupting the preferential growth trend of the dendrite tip. Under the coupling action of the above-mentioned mechanism, a stable interface is finally formed, effectively improving the interface stability and cycle performance of the battery.

[0054] like Figure 3 As shown in the figure, the vertical axis is the interface impedance increment, an arbitrary unified unit, and the horizontal axis is the number of cycles. The legend part uses the group as the title, and indicates the comparative results of the two groups of data of the experimental group and the control group, where the experimental group corresponds to the solid line curve and the control group corresponds to the dotted line curve. It can be seen from the figure that with the increase of the number of cycles, the interface impedance increment of the control group shows a continuous upward trend, and it significantly rises to nearly 400 units at the 500th cycle, showing a typical irreversible interface degradation feature; while the experimental group, under the condition of introducing controllable micro-amplitude high-frequency acoustic vibration perturbation, realizes the redistribution of sodium ion migration path, dynamic guidance of interface stress and effective suppression of sodium dendrite budding state through the acoustic streaming effect, resulting in its interface impedance increment maintaining low fluctuations throughout the 500 cycles and tending to a stable state, reflecting the enhancement effect of the acoustic vibration regulation mechanism on the long-term stability of the interface between the solid electrolyte and the sodium negative electrode.

[0055] Example 4: In the practical application of a high-rate charge-discharge solid-state sodium-ion battery for a wind-solar-storage integrated microgrid system, the battery system often faces complex operating conditions such as significant day-night temperature difference, large fluctuations in current density, and frequent switching of charge and discharge states during operation. Such operating conditions can easily induce instantaneous mismatch between the solid electrolyte and the sodium negative electrode interface, resulting in uneven ion migration, concentration of local contact stress, and early germination of sodium dendrites. In order to effectively cope with the interface stability challenges brought about by such dynamic mismatch, in this embodiment, a set of interface perception and adaptive control mechanisms based on acoustic vibration disturbances are integrated into the battery management system. The system consists of an interface state recognition module, a parameter self-tuning sound and vibration control module, and a closed-loop feedback analysis module. The three work together efficiently during the dynamic operation of the battery to form a closed-loop control path of perception-judgment-regulation-verification. In this operating scenario, the battery management system collects the rate of change of the battery's current, voltage, and interface impedance in real time, and identifies the current fluctuation boundary and the interface impedance mutation point based on the difference trend between the current measurement data and the historical reference data, combined with the differential sliding average method. Once it is detected that the current change rate exceeds the first current change threshold preset by the system, or the growth rate of the interface impedance per unit time exceeds the second The impedance change rate threshold is used to determine whether the battery has entered the interface dynamic mismatch risk period. In this embodiment, the setting of the first current change threshold is based on the maximum deposition rate of sodium metal in the solid electrolyte interface and its response time to the stripping behavior. The second impedance change rate threshold is obtained through the induction of long-term operating cycle tests to ensure that it has sufficient sensitivity while also avoiding misjudgments caused by normal fluctuations. After confirming that it has entered the risk period, the system immediately activates the piezoelectric ceramic thin layer structure integrated on the surface of the sodium negative electrode current collector. The piezoelectric device adopts a multi-layer laminate design with a thickness controlled at about 20 microns and is directly formed by a screen printing process. On a metal substrate, to maintain a stable acoustic coupling relationship, under the control of the battery management system, the piezoelectric device generates an acoustic vibration disturbance signal with a frequency of 1,000 Hz to 10 MHz and an amplitude of 1 nanometer to 10 microns. Its specific frequency and amplitude parameters are dynamically adjusted according to the current interface state. To ensure a good match between the excitation frequency and the interface acoustic impedance and avoid energy loss, the acoustic vibration control module presets a set of mapping relationships between the frequency and the interface impedance response characteristics. During operation, the excitation parameters are adjusted in real time according to the changes in the attenuation peak displacement within the interface response frequency band, thereby dynamically locking the optimal coupling frequency to maximize the excitation efficiency of the acoustic streaming effect.

[0056] During the implementation of acoustic vibration disturbance, the system transmits a set of high-precision acoustic probe signals at the beginning or intermittent period of each excitation cycle. The signal consists of a sweep pulse sequence composed of multiple frequency bands, covering a frequency range of one kilohertz to three megahertz. The power level is maintained in a low-energy range that does not interfere with the main excitation signal. The acoustic pickup module synchronously collects the probe signal and the reflected waveform after the interface action through a miniature receiving array arranged inside the battery shell. The system uses harmonic analysis and phase delay demodulation algorithms to extract key acoustic echo characteristics, including the attenuation degree of the echo amplitude of the target frequency point, the frequency band position and number of abnormal harmonic components, and the phase offset of the main wave packet, to comprehensively judge the stability level of the current interface contact state and predict the dendrite initiation accordingly. When the system determines that the current interface presents a highly non-uniform ion distribution or there are signs of microcrack initiation, it will immediately adjust the waveform and action rhythm of the acoustic vibration disturbance, such as switching the original single-frequency sinusoidal excitation mode to an FM composite waveform, and appropriately extending the duration of the disturbance to enhance the coverage of the acoustic flow disturbance in the edge area, and accelerate the reconstruction of the sodium ion distribution on the interface and the active guidance of the contact stress; in this embodiment, the acoustic flow effect plays a role in multiple dimensions. In terms of ion migration, a nanoscale oscillating potential field is formed in the interface area through acoustic vibration excitation, which effectively guides the sodium ion migration path originally concentrated in the local high electric field area to diffuse to the whole, thereby improving the overall transmission uniformity of the interface; in terms of structural mechanics, acoustic vibration The disturbance provides additional kinetic energy to the interface atoms or ions, causing them to complete local rearrangement under the action of the stress field caused by the volume change, thereby effectively weakening the stress concentration effect. In terms of sodium dendrite evolution control, the acoustic flow disturbance applied to the dendrite germination area can induce non-uniform vibration energy distribution, causing its growth direction to become unstable or structural dislocation to occur. It can also induce its backflow and form a more uniform deposition morphology, interrupting its trend of evolution towards a destructive morphology. To verify the actual effectiveness of the above mechanism, comparative experiments were conducted through multiple sets of standard cycle conditions during the system testing phase. The results showed that in the system adopting this implementation scheme, the interface impedance stability coefficient was significantly better than that of the control system without disturbance control. Typical data showed that the coefficient decreased by more than 20%. The duration for which the interface structure remains in a uniform and stable state is also significantly extended, verifying the actual effect of this method in improving interface stability and transmission uniformity in a complex operating environment; in terms of the selection of acoustic devices, this embodiment preferably uses lead zirconate titanate piezoelectric ceramics doped with sodium and potassium ions, whose acoustic impedance forms a good coupling match with the composite polymer-based solid electrolyte, effectively improving the energy transfer efficiency and interface response sensitivity; in order to further improve the reliability of the system, a multi-layer flexible buffer membrane is arranged between the device and the battery casing to filter out undesired excitation signals that may be caused by external mechanical vibrations or environmental disturbances, ensuring that the acoustic flow disturbance maintains high selectivity and stability at the electrochemical level, which are all extended implementation methods known to ordinary technicians in this field.

[0057] Example 5: In a practical application of a regional distributed energy storage system, the system adopts an energy dispatching structure with solid-state sodium-ion batteries as the core energy storage unit, and is deployed in a plateau urban-rural power complementary network with significant day and night temperature differences, frequent load fluctuations and poor grid stability. In such an operating environment, when the system transitions to a standby state during the high-power discharge phase after sunset, the charge and discharge currents usually fluctuate violently, which can easily lead to dynamic stress mismatch at the interface between the solid electrolyte and the sodium negative electrode, thereby inducing local nucleation of sodium dendrites, affecting the battery's cycle stability and output consistency. To solve this problem, in this embodiment, the solid-state sodium-ion battery system is configured with a set of acoustic vibration control modules and an intelligent response mechanism for the interface state, which is used to identify the interface mismatch risk in real time under the above-mentioned typical operating conditions and perform corresponding acoustic flow activation operations to dynamically maintain interface stability and achieve uniform regulation of sodium ion transmission. The identification mechanism introduces an empirical model constructed based on the historical current change rate curve and the interface impedance fluctuation range, and combines the battery operating state parameters collected in real time to compare the current change slope. Whether the impedance disturbance amplitude synchronously crosses the cooperative threshold window set by the model, the threshold window is obtained through statistical analysis of fifty groups of working condition data under a typical plateau day and night cycle operation period, and has strong adaptability and generalization ability. Once it is judged that the current working state exceeds the threshold range, the system triggers the activation operation of the acoustic vibration control module; the acoustic vibration module includes a piezoelectric thin layer integrated on the surface of the sodium negative electrode current collector and a low-power drive circuit arranged inside the battery shell. The piezoelectric thin layer adopts a multi-layer lead zirconate titanate-based ceramic stacking structure, which is screen-printed by a screen printing process. The thin layer is attached to the surface of the sodium negative electrode metal backplane. When the driving circuit applies an electrical signal, the thin layer generates surface acoustic wave disturbances with a frequency between 3 kilohertz and 5 megahertz and an amplitude of 5 nanometers to 5 microns. In actual applications, the driving signal is loaded in the form of periodic variable frequency pulses. The initial five disturbance cycles are set as linear frequency modulation envelopes to activate interface areas at different depths to generate acoustic flow responses. It is then switched to an amplitude modulated sine wave signal to maintain a steady-state disturbance. The duration and waveform combination of the disturbance are adjusted in real time by the battery management system based on the acoustic feedback characteristics.

[0058] In order to realize the closed-loop control mechanism, the system inserts an acoustic probe signal emission operation in each round of disturbance cycle. The signal is injected into the interface area in the form of dual-frequency coupled pulses. The interface response signal is collected by the micro piezoelectric pickup unit arranged at different positions of the battery shell and transmitted to the back-end signal processing module for analysis. The processing module extracts the frequency domain features from the collected echo signal, including the high-frequency harmonic amplitude change rate, the main frequency peak displacement and the phase lag factor. If the main frequency peak displacement is detected to exceed twice the standard deviation of the drift mean in the static state, the system determines that the current interface is The surface may have asymmetric ion migration trend or local contact structure imbalance. Based on this, the acoustic vibration frequency is adjusted to the maximum acoustic coupling range corresponding to the offset direction, and the amplitude is increased by 30% to 40% to enhance the local effect of the acoustic flow on the imbalance area. This regulation mechanism effectively reduces the ion flux density in the high electric field concentration area by adjusting the microscopic distribution of sodium ions in the interface area, destroying the advantageous conditions for the initial tip growth of sodium dendrites. At the same time, the local pore area in the interface obtains additional micro-kinetic energy due to the acoustic vibration disturbance, and the atomic-level structure undergoes local rearrangement under the action of stress, thereby reducing The system weakens stress concentration effects and suppresses the formation of microcracks, enhancing the structural fatigue resistance of the interface during multiple charge-discharge cycles. During system operation, the long-term effectiveness of this acoustic-vibration control mechanism is quantitatively evaluated using the interface impedance stability coefficient. Specifically, the system automatically performs an acoustic health diagnosis after every fifty charge-discharge cycles. The acoustic-vibration excitation unit emits a sweeping excitation signal covering five different frequency ranges, with each segment lasting less than 200 milliseconds. The pickup unit then synchronously collects the echo signal and generates a spectrum image of the current interface state. This image is compared with the previous historical spectrum to extract the frequency peak position and intensity change trend. The analysis results are used to update the weights of various parameter combinations in the interface health prediction model. Verification under multiple typical operating conditions shows that the acoustic-vibration control mechanism can reduce the interface impedance stability coefficient by an average of more than 20%. Scanning images of sodium dendrites show a more uniform deposition morphology, and interface profile analysis shows no obvious signs of structural collapse, demonstrating that this scheme can effectively improve the energy conversion efficiency and interface stability of sodium-ion batteries under complex dynamic conditions.

[0059] Example 6: This example aims to verify the practical effectiveness of low-amplitude, high-frequency acoustic perturbation technology in improving the dynamic stability of the interface between the solid electrolyte and the sodium anode, and to clarify its mechanism of action in inhibiting the early nucleation and growth of sodium dendrites. This experiment is based on the existing solid-state sodium-ion battery under high-rate charge and discharge conditions, where local stress accumulation at the interface leads to contact degradation and dendrite penetration. The goal is to achieve adaptive optimization of the interface state through active intervention.

[0060] The experiments were conducted on a customized battery testing platform, which integrates a precision constant temperature control unit, a high-precision charge-discharge test system, and an integrated module specifically designed for acoustic interface control. The test battery's positive electrode consisted of a layered oxide material, the negative electrode was a sodium foil, and the solid-state electrolyte was a composite of acoustically sensitive polymers and inorganic materials. Its acoustic impedance was optimized to ensure effective coupling and transfer of acoustic energy. To accurately identify periods of potential interface dynamic mismatch risk during charge and discharge, the experiments focused on the absolute rate of change of the battery's charge and discharge currents and the instantaneous rate of increase of the interface impedance. The first current change threshold was determined based on the maximum allowable deposition rate of sodium metal at the solid-state electrolyte interface and its response to remodeling from a dendritic morphology to a flat deposition structure. Cycling tests of multiple batches of solid-state sodium-ion batteries at various charge and discharge rates, combined with subsequent anatomical analysis, confirmed that the probability of dendrite nucleation increases when the absolute value of the charge or discharge current changes by more than a specific percentage within any continuous period. In practical applications, this threshold can be based on statistical analysis of historical operating data, aiming to balance early warning sensitivity with robustness to avoid false positives.

[0061] The determination of the second impedance change rate threshold is based on the long-term monitoring of the tiny, reversible fluctuation characteristics of the interface impedance of the battery in the early stage of normal cycle life (for example, the first 100 cycles). The battery is periodically tested by electrochemical impedance spectroscopy. When microscopic contact failure or dendrite sprouts occur at the interface, the impedance growth will accelerate. The threshold can be set according to the normal fluctuation range and empirical tolerance during system operation to effectively capture early degradation signals. The core acoustic vibration device is a piezoelectric ceramic thin layer, which is integrated on the surface of the sodium negative electrode current collector through a screen printing process. The initial frequency range of the acoustic vibration disturbance can be set between 1 kHz and 10 MHz, and the amplitude range can be set between 1 nm and 10 μm. The selection of these parameters can be based on acoustic simulation and material resonance characteristic testing, aiming to cover the range that can effectively stimulate the acoustic streaming effect without destroying the battery material structure. In actual applications, these parameters can be optimized through acoustic probe signal feedback to enable it to adapt to the regulation needs under different interface states.

[0062] The experiment was conducted by setting up a control group (without acoustic vibration control) and an experimental group (with acoustic vibration control) to verify the actual effect of acoustic vibration control. Both groups of batteries were charged and discharged in a constant current and constant voltage mode at a specific temperature. When the experimental group of batteries were determined to have entered a risk period by the interface dynamic mismatch risk identification module, the system activated acoustic vibration control. Before the application of acoustic vibration disturbance or during the interval, the piezoelectric thin layer served as an acoustic vibration generating unit and an acoustic probe unit, emitting a preset acoustic probe signal to the interface area. This signal consists of a swept pulse sequence composed of multiple frequency bands, and its power level is maintained at a low energy level range that does not interfere with the main excitation signal. At the same time, the micro-receiving array (acoustic pickup unit) arranged inside the battery shell synchronously collects the probe signal and the reflected waveform after the interface interaction. The system's built-in signal processing module uses harmonic analysis and phase delay demodulation algorithms to extract key acoustic reverberation features in real time. When the attenuation degree of the reverberation amplitude of the target frequency point, the frequency band position and number of abnormal harmonic components, and the phase offset of the main wave packet are monitored to show abnormal changes, the system determines that the current interface may have an asymmetric ion migration trend or a local contact structure imbalance. Once such anomalies are identified, the control module can call a preset parameter optimization strategy. For example, if the displacement of the main frequency peak exceeds a specific offset mean, the system will adjust the acoustic vibration frequency to the acoustic coupling range corresponding to the offset direction, and at the same time increase the amplitude to enhance the local effect of the acoustic flow on the imbalanced area.

[0063] During the application of acoustic vibration perturbations, the acoustic streaming effect exerts a multi-dimensional effect at the interface. Acoustic excitation forms an oscillating potential field at the interface, which helps guide the sodium ion migration path toward overall diffusion and improves the overall transmission uniformity of the interface, thereby reducing the local overpotential for dendrite nucleation during the charging process. The micro-amplitude, high-frequency acoustic vibration perturbations provide additional kinetic energy to the interface atoms or ions, promoting their local rearrangement under the stress field generated by the volume change caused by sodium metal deposition and stripping, thereby effectively weakening the stress concentration effect and avoiding the initiation of interface microcracks. In addition, the application of acoustic streaming perturbations to the dendrite germination area can induce a non-uniform vibration energy distribution, slightly disturbing the ion concentration field and electric field distribution near the sodium dendrite tip, thereby weakening its preferential growth advantage. The acoustic streaming effect can also promote the re-spreading or flattening of already formed small, loose sodium deposits on the interface, effectively blocking their evolution into destructive dendrites.

[0064] In this embodiment, the performance evaluation of the experimental group and the control group batteries can be carried out for 500 charge and discharge cycles, and the interface impedance stability coefficient S Z As a quantitative evaluation indicator, it is defined as: Where ΔZ cis the interface impedance increment under cycle number c, ΔZ0 is the initial interface impedance increment, which can be understood as the interface reference state after the battery undergoes the first stable cycle. The impedance change amplitude corresponding to each specific cycle number will be compared with the reference state to measure the degree of fluctuation of interface stability. In the control group, the interface impedance increment generally showed an upward trend compared with the initial impedance increment. In the experimental group, especially under high-rate charge and discharge conditions, after the system detected the risk of dynamic interface mismatch multiple times and implemented acoustic vibration control, S Z The values ​​show a tendency to stabilize or stage-by-stage self-repair characteristics during long-term cycles, which indicates that the acoustic streaming effect effectively suppresses the irreversible growth of the interfacial impedance.

[0065] After the cycle, the two groups of batteries were dissected and observed by scanning electron microscopy (SEM). Irregular and sharp sodium dendrite penetration marks, as well as interface stratification and microcracks were observed at the sodium negative electrode surface and solid electrolyte interface of the control group. The sodium negative electrode surface of the experimental group battery was relatively flat, the sodium deposition phenomenon was suppressed, no obvious sharp dendrites penetrated the solid electrolyte, the interface contact was more uniform, and the number of microcracks was reduced. This intuitively confirms the effectiveness of the acoustic streaming effect in dendrite suppression and stress relief. Compared with the control group, the cycle life of the experimental group battery showed improvement. In safety tests such as simulated overcharge or external short circuit, the experimental group battery did not experience thermal runaway and other phenomena, achieving enhanced battery energy conversion efficiency and safety performance, which are all extended implementation methods known to ordinary technicians in this field.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-safety sodium ion battery energy conversion method based on solid electrolyte, characterized in that: The method comprises the following steps: Step a, identifying a specific interface dynamic mismatch risk period during the charge and discharge process of the sodium ion battery, wherein the identification of the risk period is based on the dynamic change rate of the battery current, voltage or interface impedance; Step b, applying a micro-amplitude high-frequency acoustic perturbation to the interface region between the solid electrolyte and the sodium negative electrode during a specific interface dynamic mismatch risk period, wherein the acoustic perturbation generates an acoustic streaming effect in the interface region, thereby regulating the microscopic distribution of sodium ions at the interface, channeling the local contact stress generated by volume change at the interface, and inhibiting the early nucleation and local aggregation of sodium dendrites; Step c: Through the acoustic streaming effect, the migration path of sodium ions in the interface region between the solid electrolyte and the sodium negative electrode is continuously and adaptively induced to be redistributed, and the microstructure of the interface atoms or ions is caused to rearrange under the action of local stress, thereby forming a stable state of the interface contact morphology to adapt to the interface stress changes during the charge and discharge cycle.

2. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: Identifying a specific interface dynamic mismatch risk period in step a includes: determining it as a specific interface dynamic mismatch risk period when the absolute value of the charging current or discharging current of the sodium ion battery exceeds a preset first current threshold, or when the interface impedance change rate of the battery exceeds a preset second impedance change rate threshold.

3. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: Applying controllable micro-amplitude high-frequency acoustic vibration disturbance in step b includes: before applying the acoustic vibration disturbance or during its interval, transmitting a preset acoustic probe signal to the interface area by an acoustic vibration generating unit or an independent acoustic probe unit; capturing and qualitatively analyzing the acoustic reverberation characteristics formed after the interaction between the acoustic probe signal and the interface area by an acoustic pickup unit, the acoustic reverberation characteristics including attenuation degree of a specific frequency, abnormal harmonic components or at least one of phase delay; and dynamically adjusting at least one parameter of the micro-amplitude high-frequency acoustic vibration disturbance according to the instantaneous state of the interface indicated by the acoustic reverberation characteristics, the parameter being selected from a combination of frequency, amplitude, waveform, action duration or application mode.

4. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: The application of controllable micro-amplitude high-frequency acoustic disturbance in step b is achieved by any of the following methods: the acoustic disturbance is derived from the mechanical vibration or acoustic signal endogenous to the sodium ion battery under specific electrochemical reaction conditions, and the acoustic resonance structure of the battery's current collector or solid electrolyte is designed to utilize or amplify the endogenous vibration; or, the acoustic disturbance is generated on demand by a micro-acoustic device integrated inside or outside the sodium ion battery and acoustically coupled to the sodium negative electrode current collector or solid electrolyte under the control of the battery management system.

5. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 4, characterized in that: The micro-acoustic vibration device is a thin layer of piezoelectric ceramic or a magnetostrictive film. The micro-acoustic vibration device is integrated on the surface of the sodium negative electrode current collector through screen printing or sputtering process; the frequency range of the micro-high-frequency acoustic vibration disturbance is 1 kHz to 10 MHz, and the amplitude range is 1 nanometer to 10 microns.

6. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: The inhibition of early nucleation and local aggregation of sodium dendrites specifically includes: the acoustic streaming effect slightly disturbs the ion concentration field and electric field distribution near the tip of the sodium dendrite, thereby weakening its preferential growth advantage; or, promotes the re-spreading or flattening of the already formed tiny, loose sodium deposits on the interface.

7. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: The relief of interface contact stress includes: micro-amplitude high-frequency acoustic vibration disturbance provides additional tiny kinetic energy to interface atoms or ions, promoting their local rearrangement under stress and diffusion of stress points.

8. The high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1, characterized in that: The acoustic streaming effect makes the interface impedance show the characteristics of stabilization or staged self-repair in long-term cycles, and the stability coefficient of the interface impedance S Z satisfy: Where ΔZ c is the interface impedance increment under cycle number c, ΔZ0 is the initial interface impedance increment, and α is the preset interface impedance stability threshold percentage. The lower the stability coefficient, the better the stability of the interface impedance.

9. A high-safety sodium ion battery energy conversion method based on solid electrolyte according to claim 1 or 2, characterized in that: It also includes performing the following interface health diagnosis steps at a preset life cycle node of the sodium ion battery: Step 1, driving the acoustic vibration generating unit or the independent acoustic probe unit to generate a swept-frequency acoustic excitation or a multi-frequency acoustic pulse sequence covering a preset frequency range in the interface area; Step 2, capturing and processing the acoustic response of the interface area to the swept-frequency acoustic excitation or the multi-frequency acoustic pulse sequence through the acoustic pickup unit to generate an acoustic resonance characteristic spectrum or fingerprint data characterizing the current interface state, the acoustic resonance characteristic spectrum or fingerprint data including at least one of the position of the main resonance peak, the relative intensity or peak width of the resonance peak, and the relative change of the average acoustic absorption or reflection coefficient in a specific frequency band; Step 3, comparing and analyzing the currently generated acoustic resonance characteristic spectrum or fingerprint data with historical data to identify the evolution trend of the acoustic resonance characteristic spectrum or fingerprint data; Step 4, based on the evolution trend, evaluating the long-term health status of the interface, predicting its remaining service life, or triggering early warning maintenance instructions.

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