Dual-mode solid-state battery simulation test apparatus and test method

Abstract

This application provides a dual-mode solid-state battery simulation testing device, including a cylindrical electrolytic cell housing, tabs, and a loading observation component disposed in the housing; the housing is formed as a cylindrical column, with annular grooves for sealing and multiple screw holes for fixing a cover plate respectively provided on the surfaces of its upper and lower edges; the tabs are disposed on the outside of the housing for the current generated by the solid-state battery; the loading observation component includes: a top cover plate, a top sealing ring, a transparent conductive film, a positioning element, a lower current collector, a pressure sensor, a first insulating gasket, a piezoelectric actuator, a second insulating gasket, a bottom sealing ring, and a bottom cover plate.

Description

Technical Field

[0001] This application relates to the field of solid-state battery testing, and more particularly to a dual-mode solid-state battery simulation testing device. Background Technology

[0002] Electrodeless solid-state lithium metal batteries greatly improve the theoretical specific capacity of batteries because they simplify the initial lithium anode in structure and form an anode layer in situ on the current collector during the first discharge process. Furthermore, the use of a thermodynamically stable solid electrolyte further enhances the safety of the battery, making them one of the most promising new solid-state battery systems.

[0003] During the in-situ formation of the lithium anode, lithium undergoes uneven deposition at the current collector-solid electrolyte interface, resulting in significant volume expansion. This leads to non-uniform stress accumulation within the electrode, affecting the equilibrium voltage and interfacial driving force, thus causing electrode interface degradation. To improve the contact performance of the current collector-solid electrolyte interface, external stacking pressure is typically applied during battery charge-discharge testing.

[0004] However, current battery testing devices mostly use compression springs or fastening bolts to apply pressure. These methods are difficult to achieve uniform load distribution and lack in-situ observation equipment that can dynamically adjust pressure for stress regulation and in-situ real-time observation during battery cycling. This invention addresses this issue. This invention provides a negative electrode-free all-solid-state battery testing device, aiming to achieve uniform pressure application at the current collector-solid electrolyte interface and possess the ability to dynamically adjust pressure for stress regulation and in-situ real-time observation during battery cycling. Summary of the Invention

[0005] In view of this, this application provides a dual-mode solid-state battery simulation testing device, including a cylindrical electrolytic cell shell, tabs, and a loading observation component disposed in the shell; the shell is formed as a cylindrical column, with annular grooves for sealing and multiple screw holes for fixing a cover plate respectively provided on the surfaces of its upper and lower edges; the tabs are disposed on the outside of the shell for the current generated by the solid-state battery; the loading observation component includes: a top cover plate, a top sealing ring, a transparent conductive film, a positioning element, a lower current collector, a pressure sensor, a first insulating gasket, a piezoelectric actuator, a second insulating gasket, a bottom sealing ring, and a bottom cover plate; the top cover plate is bolted to seal the upper end of the shell, pressing the top sealing ring to the annular groove on the upper edge of the shell, and the top cover plate has a transparent observation... The bottom cover is bolted to seal the lower end of the housing, and the bottom sealing ring is pressed into the annular groove at the lower edge of the housing; the lower surface of the top cover abuts against the transparent conductive film to restrict the upward movement of the solid-state battery placed in the positioning member and to conduct current through the transparent conductive film; the preload pressure of the solid-state battery in the vertical direction is adjusted by adjusting the tightening of the bolts of the top cover and / or the bottom cover; the force of the bottom cover acts on the lower surface of the solid-state battery through the second insulating gasket, the piezoelectric actuator, the first insulating gasket, and the lower current collector; the pressure sensor abuts between the lower current collector and the first insulating gasket or between the second insulating gasket and the bottom cover; the piezoelectric actuator is composed of multiple disc-shaped piezoelectric plates stacked together to apply vibration loads and / or pressure loads.

[0006] Furthermore, at least two of the piezoelectric plates have different thicknesses or different materials to simulate multi-frequency loading under complex working conditions.

[0007] Furthermore, the first insulating pad and / or the second insulating pad are made of non-rubber / plastic materials.

[0008] Furthermore, the first insulating pad and / or the second insulating pad are made of ceramic material.

[0009] Furthermore, the positioning element is formed as a circular structure with a central columnar through hole and a uniform thickness, and is made of a metallic material.

[0010] Furthermore, the coefficient of thermal expansion of the metal material at 20°C is greater than 17 × 10⁻⁶. -6 / ℃.

[0011] Furthermore, the metal material is aluminum alloy and / or stainless steel.

[0012] Furthermore, the diameter of the central columnar through hole is less than or equal to 50% of the diameter of the positioning element, so that the prestress generated by the expansion and contraction of the positioning element can be uniformly applied to the circumference of the solid-state battery.

[0013] Furthermore, the inner wall of the positioning member has a holding and bearing structure for fixing the solid-state battery.

[0014] According to another aspect of the embodiments of this application, a simulation testing method for solid-state batteries is also provided, characterized by comprising the following steps: placing the solid-state battery in a specific constant temperature state for more than 10 minutes to allow it to shrink into a stable shape; placing a positioning member in a specific constant temperature state for more than 10 minutes to allow it to fully expand; installing the solid-state battery in the positioning member at room temperature, such that the positioning member forms a radial preload on the solid-state battery; installing the positioning member in any of the above-mentioned dual-mode solid-state battery simulation testing devices for load testing; driving the piezoelectric actuator to generate axial vibration and / or a stable loading force, observing the surface changes of the solid-state battery through an observation window, and detecting the current and / or voltage output through the tabs.

[0015] The beneficial effects of the embodiments of the present invention include at least the following:

[0016] Axial pressure is applied using a piezoelectric actuator, which can apply uniform and controllable pressure to the interface, achieve displacement control with sub-nanometer resolution, high pressure regulation accuracy, and fast response speed. By setting the applied electric field voltage change, cyclic load can be applied during battery cycling, and dynamic stress modulation can be achieved during battery cycling.

[0017] At the same time, real-time observation of the current collector surface was achieved during the charging and discharging process of the electrodeless all-solid-state battery;

[0018] Meanwhile, the device can achieve multifunctional in-situ characterization, and can be used for in-situ XRD characterization, energy dispersive spectroscopy analysis, etc. during battery charging and discharging.

[0019] Furthermore, the forces applied by traditional loading methods are generally static, such as applying a pressure of 200N to observe the charge and discharge performance of solid-state batteries under this pressure condition, especially the interface effect and dendrite formation. However, in actual working conditions, there are also vibration effects. According to the embodiments of the present invention, not only can static loading forces be applied, but its piezoelectric stack or piezoelectric layer can also output a vibration field, thereby simulating the working performance of solid-state batteries under complex multi-field loading environments in real working conditions, which is closer to the actual working conditions.

[0020] Furthermore, in all-solid-state batteries, the mechanochemical coupling in the solid-state electrode has a significant impact on battery performance. To improve interfacial contact, in-situ electrolyzer designs typically employ axially applied stacking pressure. However, during charge and discharge, problems such as lithium dendrite growth and crack propagation may occur. Since the stacking pressure is parallel to the crack propagation direction, it cannot effectively suppress cracks.

[0021] Therefore, in addition to applying a uniform axial loading force to the surface of the solid-state battery, it is also desirable to simulate the application of radial constraints to observe the growth and evolution of cracks under different constraint conditions. The embodiments of the present invention also solve this problem, thereby realizing the application of pre-tightening force fields under different complex working conditions in the axial loading and the application of constraint force fields in the radial direction, thereby obtaining the optimal operating environment for solid-state batteries with different structures and compositions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall appearance of a dual-mode solid-state battery simulation test device provided in one embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the internal structure of a dual-mode solid-state battery simulation test device provided in one embodiment of this application;

[0025] Figure 3 This is a schematic diagram of a dual-mode solid-state battery simulation test method provided in one embodiment of this application. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings.

[0027] Figure 1 A schematic diagram of the overall appearance of a dual-mode solid-state battery simulation test device according to an embodiment of this application is shown. It includes a cylindrical shell 7 with a certain thickness, and a ring-shaped sealing groove 702 is provided on the cross-section of its upper edge, as well as a plurality of evenly distributed screw holes 701. The outer wall of the shell 7 is also provided with tabs 8 for discharging the current generated by the solid-state battery to measure its operating performance, including voltage and current.

[0028] Figure 2An exploded view of the dual-mode solid-state battery simulation test device according to an embodiment of the present invention is shown. The device includes a transparent glass window 11, a transparent conductive film 12, bolts 2, a top cover plate 31, a bottom cover plate 32, a top sealing ring 41, a bottom sealing ring 42, an annular positioning element 14, a lower current collector 13 placed in the groove of the annular positioning element 14, a pressure sensor 5, an insulating gasket 61, a piezoelectric actuator 62, a cylindrical electrolytic cell body 7 for placing the battery and related test components, and tabs 8.

[0029] Non-limiting, the transparent glass window 11 and the top cover plate 31 can be formed as one piece or combined. The top cover plate 31 is adjustablely fixed to the upper edge of the outer shell 7 by multiple bolts 2, and the depth of the top cover plate 31 pressed into the outer shell 7 can be adjusted by adjusting the bolts 2, thereby adjusting the static pressure of the top cover plate 31 on the solid-state battery.

[0030] Similarly, the bottom cover 32 is also adjustablely fixed to the bottom of the housing 7 by multiple bolts, and the force exerted by the bottom cover 32 on the insulating gasket 61 and the piezoelectric actuator 62 can be adjusted by adjusting the screwing depth of the bolts, thereby adjusting the static force acting on the lower surface of the solid-state battery.

[0031] like Figure 2 As shown, the insulating pad 61 includes a first insulating pad disposed on the upper part of the piezoelectric actuator 62 and a second insulating pad disposed on the lower part thereof. Both are made of a non-metallic rigid material, preferably made of ceramic material, and cannot be made of common insulating materials such as rubber or plastic, so as to avoid affecting the transmission of vibration output by the piezoelectric actuator 62, that is, to prevent vibration from being absorbed.

[0032] When the dual-mode solid-state battery simulation test device of this application is running, the battery under test (not shown) is placed on the lower current collector 13. At this time, the pressure sensor is placed at the bottom of the annular positioning member 14, which can monitor the stacking pressure generated by the piezoelectric actuator 62 under the action of the electric field. Insulating pads 61 need to be placed on the upper and lower surfaces of the piezoelectric actuator 62. The piezoelectric actuator 62 needs to be set with pre-tightening pressure before use. During the battery cycle, a uniform and variable axial pressure is applied to the battery surface by adjusting the electric field.

[0033] In addition, the electrolytic cell 7 is equipped with a tab 8 for providing current connection with the annular positioning component 14. A transparent glass window 11 is located at the center of the top cover 31 for observing the morphological evolution of the lithium deposition interface during battery operation. A transparent conductive film 12 is attached to the bottom of the window as an upper current collector, without affecting in-situ observation. The glass window 11 should be made of a hard transparent material, such as quartz glass, transparent acrylic, or sapphire. The transparent conductive film should be made of a transparent material with high conductivity and high light transmittance, such as indium tin oxide. In this example, the in-situ testing device forms a sealed environment for the battery testing device through the cavity 7, top cover 31, top sealing ring 41, bottom sealing ring 42, bottom cover 32, and bolts 2.

[0034] Non-limiting, the piezoelectric actuator 62 is composed of multiple disc-shaped piezoelectric plates 620 stacked together to apply vibrational loads and / or pressure loads. Each piezoelectric plate 620 may be made of different materials and / or have different thicknesses. Each piezoelectric plate 620 may be controlled by an independent circuit to generate vibrations or extensions at different frequencies.

[0035] Non-limiting, the dual-mode solid-state battery simulation test apparatus according to the present invention requires calibration before testing to determine the relationship between the input signal and the output pressure and vibration. Each piezoelectric plate deforms under the action of an electric field, and when these deformations accumulate, a large displacement is generated, thereby outputting high-frequency vibration. The vibration frequency of the piezoelectric actuator 620 in the form of a piezoelectric stack depends on the frequency of the applied voltage. To output high-frequency vibration, a high-frequency electrical signal is required. The natural frequency and mechanical quality factor of the piezoelectric stack affect its response to high-frequency signals.

[0036] Non-limiting, when a DC voltage is input to the piezoelectric plate 620 of the piezoelectric actuator 62, a constant DC voltage needs to be applied to it. When a DC voltage is applied to the piezoelectric stack, the piezoelectric ceramic sheet inside it will undergo linear deformation. A constant DC voltage needs to be applied to it. When a DC voltage is applied to the piezoelectric stack, the piezoelectric ceramic sheet inside it will undergo linear deformation.

[0037] Furthermore, in the piezoelectric actuator 62 of the dual-mode solid-state battery simulation test apparatus according to an embodiment of the present invention, at least one piezoelectric plate 620 is supplied with DC power to apply static pressure to the solid-state battery, and / or at least one piezoelectric plate 620 is supplied with AC power to apply vibration loading to the solid-state battery.

[0038] Furthermore, different frequencies of alternating current can be input to different piezoelectric plates 620 to simulate a real vibration condition, thereby observing the operation of solid-state batteries under static pressure and multi-frequency vibration.

[0039] It should be understood that the static pressure includes not only the static pressure applied to the solid-state battery through the top pressure plate 31 and / or the bottom pressure plate 32, and the static pressure applied through the piezoelectric actuator 62, all of which act in the axial direction perpendicular to the upper and lower surfaces of the solid-state battery; the static pressure also includes the radial force applied to the circumference of the solid-state battery by the shrinking of the positioning member 14 as the temperature changes, i.e., the radial constraint force. This constraint field can help limit, constrain, and prevent the solid-state battery from being damaged by cross-sectional chemical reactions due to repeated charge and discharge cycles, especially the generation of nanocracks.

[0040] Non-limiting, according to an embodiment of the dual-mode solid-state battery simulation test apparatus, the positioning component is configured as a disc-shaped annular structure having a central columnar through-hole and a uniform thickness, which is made of a metallic material having a coefficient of thermal expansion greater than 17 × 10⁻⁶ at 20°C. -6 / ℃.

[0041] Furthermore, the metal material is aluminum alloy and / or stainless steel.

[0042] Although not shown, the diameter of the central columnar through hole is less than or equal to 50% of the diameter of the positioning member, so that the prestress generated by the expansion and contraction of the positioning member can be uniformly applied to the circumference of the solid-state battery. Furthermore, the inner wall of the positioning member has a holding and bearing structure for fixing the solid-state battery, such as an annular groove or an annular protrusion.

[0043] like Figure 3 As shown, according to another aspect of this application, a simulation test method for a solid-state battery is also provided, comprising the following steps: S101 placing the solid-state battery at a constant temperature to shrink and shape it; S102 placing the solid-state battery fixture at a constant temperature to expand and shape it; S103 installing the solid-state battery in the fixture under constant temperature conditions; S104 applying load using a piezoelectric actuator 62 (i.e., a piezoelectric stack) according to an embodiment of the present invention; S105 observing the surface changes and current output of the solid-state battery.

[0044] In step S101, the solid-state battery should be kept still at a constant temperature for more than 2 minutes, and preferably more than 10 minutes, so that it shrinks to an ideal ratio and produces a tolerance sufficient for it to be smoothly installed in the positioning member 14. The constant temperature should be below 25°C, and preferably below 20°C.

[0045] In step S102, the positioning component 14 should be kept stationary at a constant temperature for more than 2 minutes, and preferably more than 10 minutes, so that it expands to an ideal ratio and produces a tolerance sufficient for the solid-state battery to be installed smoothly. The constant temperature is 30-50°C. If the temperature is too high, it is easy to cause damage when in contact with the solid-state battery. In addition, when the temperature exceeds a certain temperature, the rate of increase of the coefficient of thermal expansion of the metal material will also decrease significantly.

[0046] In step S103, the constant temperature condition can be understood as room temperature, generally between 20-30℃. It should be understood that the temperature difference between step S101 and step S102 should be between 10-60℃.

[0047] In step S102, the loading includes applying alternating current and / or direct current to the piezoelectric plate 62 of the piezoelectric actuator 62 to apply vibration loading force and / or static loading force, and different frequencies of current can be applied to different piezoelectric plates 62 to apply multi-frequency combined simulated vibration to the solid-state battery.

[0048] In the description of this application, the terms "first" and "second" are used only for convenience in describing different components or names, and should not be construed as indicating or implying a sequential relationship, relative importance, or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0049] 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 application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0050] It should be noted that although specific embodiments of this application have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this application. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this application.

[0051] The examples of the embodiments in this application are intended to concisely illustrate the technical features of the embodiments in this application, so that those skilled in the art can intuitively understand the technical features of the embodiments in this application, and are not intended to be improper limitations on the embodiments in this application.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A dual-mode solid-state battery simulation test device, comprising a cylindrical electrolytic cell housing, tabs, and a loading observation component disposed in the housing; The shell is formed as a cylindrical column, with annular grooves for sealing and multiple screw holes for fixing the cover plate on the surfaces of its upper and lower edges, respectively. The tabs are disposed on the outside of the housing and are used for the current generated by the solid-state battery. The loading observation component includes: Top cover plate, top sealing ring, transparent conductive film, positioning component, lower current collector, pressure sensor, first insulating gasket, piezoelectric actuator, second insulating gasket, bottom sealing ring, bottom cover plate; The top cover is bolted to the upper end of the housing, and the top sealing ring is pressed into the annular groove on the upper edge of the housing. The top cover has a transparent observation window. The bottom cover is bolted to the lower end of the housing, and the bottom sealing ring is pressed into the annular groove on the lower edge of the housing. The lower surface of the top cover plate abuts against the transparent conductive film to restrict the upward movement of the solid-state battery placed in the positioning member and to conduct current through the transparent conductive film. The preload pressure of the solid-state battery in the vertical direction is adjusted by adjusting the tightening of the bolts on the top cover and / or the bottom cover. The force exerted by the bottom cover plate is applied to the lower surface of the solid-state battery via the second insulating pad, the piezoelectric actuator, the first insulating pad, and the lower current collector. The pressure sensor is positioned between the lower current collector and the first insulating gasket, or between the second insulating gasket and the bottom cover plate. The piezoelectric actuator is composed of multiple disc-shaped piezoelectric plates stacked together to apply vibration loads and / or pressure loads.

2. The dual-mode solid-state battery simulation test device as described in claim 1, characterized in that, At least two of the piezoelectric plates have different thicknesses or different materials to simulate multi-frequency loading under complex working conditions.

3. The dual-mode solid-state battery simulation testing device as described in claim 1, characterized in that, The first insulating pad and / or the second insulating pad are made of non-rubber / plastic materials.

4. The dual-mode solid-state battery simulation test device as described in claim 3, characterized in that, The first insulating pad and / or the second insulating pad are made of ceramic material.

5. The dual-mode solid-state battery simulation test device as described in claim 1, characterized in that, The positioning element is formed as a circular structure with a central columnar through hole and a uniform thickness, and is made of metal.

6. The dual-mode solid-state battery simulation test device as described in claim 5, characterized in that, The coefficient of thermal expansion of the metal material at 20°C is greater than 17 × 10⁻⁶. -6 / ℃.

7. The dual-mode solid-state battery simulation test device as described in claim 6, characterized in that, The metal material is aluminum alloy and / or stainless steel.

8. The dual-mode solid-state battery simulation test device as described in claim 5, characterized in that, The diameter of the central columnar through hole is less than or equal to 50% of the diameter of the positioning element, so that the prestress generated by the expansion and contraction of the positioning element can be uniformly applied to the circumference of the solid-state battery.

9. The dual-mode solid-state battery simulation test device as described in claim 5, characterized in that, The inner wall of the positioning element has a holding and bearing structure for fixing the solid-state battery.

10. A simulation testing method for solid-state batteries, characterized in that, Includes the following steps: The solid-state battery was left to stand at a specific constant temperature for more than 10 minutes to shrink into a stable shape. Place the positioning component under a specific constant temperature condition for more than 10 minutes to allow it to fully expand; At room temperature, the solid-state battery is installed in the positioning member, such that the positioning member forms a radial preload on the solid-state battery; The positioning component is installed on the dual-mode solid-state battery simulation test device as described in any one of claims 1-9 for loading test; The piezoelectric actuator is driven to generate axial vibration and / or a stable loading force, the surface changes of the solid-state battery are observed through the observation window, and the current and / or voltage output is detected through the tabs.

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