CN215728446U

CN215728446U - Impedance testing device

Info

Publication number: CN215728446U
Application number: CN202121625851.7U
Authority: CN
Inventors: 杨飞; 程忠; 林峰; 李娟娟
Original assignee: Sunwoda Electric Vehicle Battery Co Ltd
Current assignee: Xinwangda Power Technology Co ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2022-02-01
Anticipated expiration: 2031-07-16

Abstract

The application provides an impedance testing device, includes: a test housing having an accommodation space; the pressure assembly is positioned in the containing space and used for applying pressure to the structure to be tested; the environment parameter adjusting component is positioned in the accommodating space and is used for adjusting the temperature and/or humidity in the accommodating space; the impedance testing equipment is positioned outside the testing shell and is used for being electrically connected with the structure to be tested so as to test the impedance performance of the structure to be tested, the problem that the impedance characteristics of the lithium battery or the related structure under different climatic conditions are difficult to test by the scheme in the prior art is solved, and effective experimental basis can be provided for the service life and safety evaluation of the lithium battery and the lithium battery material in practical application; the specific test result can also be used for effectively evaluating the failure aging mechanism process of the lithium battery and the lithium battery material.

Description

Impedance testing device

Technical Field

The application relates to the field of impedance testing, in particular to an impedance testing device.

Background

The impedance of the lithium battery refers to the degree of resistance of current transmission in the battery when the battery works, and can be divided into direct current internal resistance and alternating current internal resistance according to a test method. The impedance value of the lithium battery has a close relationship with the factors such as the internal structure of the battery (including current collectors, positive and negative pole pieces, diaphragms, contact areas of the pole pieces/diaphragms and the like), the charge-discharge rate, the working condition temperature and the like.

Lithium battery impedance has been widely developed and used for the evaluation of the rate and power performance of lithium batteries, life estimation, analysis of anode, cathode and diaphragm materials, research of lithium ion deintercalation kinetic parameters, low-temperature cycle lithium analysis, interface SEI film, SOC prediction and the like, and becomes the most effective means for evaluating and analyzing the comprehensive performance of lithium batteries.

In recent years, various methods and devices for detecting the impedance value of a lithium battery have appeared. The patent document CN 106645953B discloses a method for estimating the internal resistance of a lithium battery, which estimates the internal resistance of the lithium battery on line according to the SOC value. The patent document with publication number CN 207472965U discloses an impedance testing device for lithium ion battery diaphragm, and during the testing process, the diaphragm is placed between two metal plates and is communicated through a wire hole for testing, so that the impedance value of the diaphragm can be obtained quickly. The testing device is lack of sealing measures, the condition of electric leakage is easy to occur between the two metal plates, and the device can not simulate the use condition of the diaphragm under the working conditions of high temperature, high pressure and the like. Patent document CN 106324355 a discloses an ac impedance testing system for a chemical device, which includes an electrochemical device, a control device, a dc adjusting branch, and a disturbance adjusting branch connected in parallel with the dc adjusting branch. However, the method has a complex working circuit and is not suitable for detecting the impedance values of materials such as pole pieces, diaphragms and the like. Patent document CN 104678173A discloses a method for testing the surface impedance of a lithium ion membrane, which comprises placing a membrane between two electrodes, moving the upper electrode by a screw to form a structure similar to a symmetrical battery, and testing the impedance of the membrane.

At present, a conventional alternating current impedance or direct current testing method cannot simulate the impedance characteristics of a lithium battery or a related structure under different climatic conditions generally, and theoretical data corresponding to practical application environments are lacked.

Therefore, a device capable of testing the impedance value of the lithium ion battery under extreme conditions is urgently needed.

SUMMERY OF THE UTILITY MODEL

The main objective of this application provides an impedance test device to solve the problem that can't test lithium cell or relevant structure impedance characteristic under different climatic conditions among the prior art.

In order to achieve the above object, according to one aspect of the present application, there is provided an impedance testing apparatus including: a test housing having an accommodation space; the pressure assembly is positioned in the containing space and is used for applying pressure to a structure to be tested; the environment parameter adjusting assembly is positioned in the accommodating space and is used for adjusting the temperature and/or humidity in the accommodating space; and the impedance testing equipment is positioned outside the testing shell and is used for being electrically connected with the structure to be tested so as to test the impedance performance of the structure to be tested.

Further, the impedance testing device further comprises: and the pressure detection equipment is positioned in the accommodating space and is used for detecting the pressure applied to the structure to be tested by the pressure component.

Further, the pressure assembly includes: the base is positioned on the bottom surface of the accommodating space; a first support structure located on the base; and the second support structure comprises a pressing part, and the pressing part is movably arranged on the first support structure along the direction close to the base so as to apply pressure to the structure to be tested, which is arranged between the pressing part and the base.

Further, the first support structure comprises: the supporting columns are arranged on the base at intervals; the second support structure further comprises: the supporting pieces are positioned on the supporting columns and are arranged at intervals with the base in the height direction of the supporting columns; the pressure applying part is a second supporting part and is movably arranged on the supporting columns, the second supporting part and the supporting parts are arranged at intervals in the height direction of the supporting columns, the pressure applying part is arranged on one side of the supporting parts, which is far away from the base, and when the impedance performance of the structure to be tested is tested, the structure to be tested is arranged between the supporting parts and the pressure applying part and is arranged on the supporting parts; the pressure detection device is located between the base and the supporting piece and located on the base.

Further, the pressure assembly includes: and the transmission structure is connected with the first support structure and used for adjusting the pressing part to move along the direction close to or far away from the base.

Further, the environmental parameter adjustment component includes: the heating device is positioned in the accommodating space and used for adjusting the temperature in the accommodating space; the humidifying equipment is positioned in the accommodating space and used for adjusting the humidity in the accommodating space; and the air exhaust equipment is communicated with the accommodating space, and the temperature and humidity equipment is used for adjusting the humidity and humidity in the accommodating space.

Further, the impedance testing device further comprises: and the temperature and humidity detection equipment is used for testing the temperature and the humidity in the accommodating space.

Further, the impedance testing device further comprises: and the correcting equipment is electrically connected with the pressure detection equipment and/or the temperature and humidity detection equipment and is used for correcting the pressure detection equipment and/or the temperature and humidity detection equipment.

Further, the test housing has an outlet hole.

Further, the test shell is a constant temperature and humidity box.

By applying the technical scheme of the application, the impedance testing device comprises a testing shell and an environmental parameter adjusting assembly, the temperature and/or the humidity of the accommodating space of the testing shell are adjusted by the environmental parameter adjusting assembly to simulate different climatic conditions, so that different testing conditions are met, the impedance performance of a lithium battery or a related structure (structure to be tested) under different climatic conditions is tested, the problem that the impedance characteristics of the lithium battery or the related structure under different climatic conditions are difficult to test by the scheme in the prior art is solved, the service life and the safety of the lithium battery and a lithium battery material in practical application can be evaluated, and effective experimental basis is provided; the specific test result can also be used for effectively evaluating the failure aging mechanism process of the lithium battery and the lithium battery material, and promoting the development of the field of the lithium battery.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 shows a schematic structural diagram of an embodiment of an impedance testing apparatus according to the present application;

FIG. 2 shows a schematic structural diagram of an embodiment of another impedance testing apparatus according to the present application;

figure 3 shows an ohmic impedance test curve for example 3.

Wherein the figures include the following reference numerals:

10. testing the shell; 20. a pressure assembly; 30. an environmental parameter adjustment component; 40. an impedance testing device; 50. a pressure detection device; 60. temperature and humidity detection equipment; 70. a correction device; 80. a processor; 90. a structure to be tested; 11. a wire outlet hole; 12. a box door; 21. a base; 22. a support pillar; 23. a support member; 24. a pressing part; 25. a transmission structure; 31. a heating device; 32. a humidifying device; 33. an air exhaust device.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, 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.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Also, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.

As described in the background art, the impedance characteristics of a lithium battery or a related structure under different weather conditions cannot be tested in the prior art, and in order to solve the above technical problems, the present application provides an impedance testing device.

In an exemplary embodiment of the present application, an impedance testing apparatus is provided, as shown in fig. 1, which includes a test housing 10, a pressure assembly 20, an environmental parameter adjustment assembly 30, and an impedance testing device 40. Wherein the test case 10 has an accommodating space; a pressure assembly 20 is positioned in the receiving space, the pressure assembly 20 being configured to apply pressure to a structure 90 to be tested; the environmental parameter adjusting assembly 30 is located in the accommodating space, and the environmental parameter adjusting assembly 30 is used for adjusting the temperature and/or humidity in the accommodating space to simulate different environmental conditions, such as high temperature and the like; the impedance testing device 40 is located outside the testing housing 10, and the impedance testing device 40 is used for electrically connecting with the structure to be tested 90 so as to test the impedance performance of the structure to be tested 90.

The impedance testing device comprises a testing shell and an environmental parameter adjusting assembly, wherein the temperature and/or humidity of the accommodating space of the testing shell is adjusted by the environmental parameter adjusting assembly to simulate different climatic conditions, so that different testing conditions are met, the impedance performance of the lithium battery or the related structure (the structure to be tested) under different climatic conditions is tested, the problem that the impedance characteristics of the lithium battery or the related structure under different climatic conditions are difficult to test by the scheme in the prior art is solved, the service life and the safety evaluation of the lithium battery and the lithium battery material in practical application can be realized, and effective experimental basis is provided; the specific test result can also be used for effectively evaluating the failure aging mechanism process of the lithium battery and the lithium battery material, and promoting the development of the field of the lithium battery.

It should be noted that the test housing may be any housing capable of forming a sealed accommodating space, and those skilled in the art can select a test structure with an appropriate structure according to actual situations. In a specific embodiment, in order to facilitate taking and placing other structural components, the test housing may include two parts, a first part and a second part, which are connected to each other and grounded, the first part has an opening, the second part is openably and closably disposed on the opening, and when it is necessary to take and place a structural component, the second part is opened, and the other structural component is taken and placed through the opening.

In order to simulate the test pressure more accurately, in an embodiment of the present application, as shown in fig. 2, the impedance testing apparatus further includes: a pressure detecting device 50 located in the receiving space, wherein the pressure detecting device 50 is used for detecting the pressure applied by the pressure assembly 20 to the structure to be tested 90.

In a specific embodiment, the pressure detection device is a pressure sensor, the test range is 0-100000kgf, and the test precision is +/-1 kgf.

In practical applications, the pressure component may be any structural component capable of applying pressure to the structure to be tested, and a person skilled in the art may set an appropriate pressure component according to practical situations, for example, a sliding groove is formed on an inner wall of the test housing, two ends of the pressure component are disposed in the sliding groove, and when pressure needs to be applied to the structure to be tested, the pressure component slides to the structure to be tested to apply pressure.

In one embodiment of the present application, as shown in fig. 2, the pressure assembly 20 includes a base 21, a first supporting structure and a second supporting structure, wherein the base 21 is located on a bottom surface of the accommodating space; the first supporting structure is positioned on the base 21; the second support structure includes a pressing portion movably disposed on the first support structure along a direction close to the base to apply a pressure to the structure to be tested 90 disposed between the pressing portion and the base. In this embodiment, due to the base 21, the structure to be tested 90 can be placed above the base 21 during testing, so as to avoid the problem that the structure to be tested 90 is directly placed on the surface of the testing shell 10, which may cause damage to the testing shell 10 during testing; in addition, the pressure assembly 20 further includes a first supporting structure for supporting a second supporting structure including the pressure applying portion, so that the structure of the whole pressure assembly 20 is more stable, the moving space of the pressure applying portion is more independent of other structures in the impedance testing apparatus, and the pressure applying portion is prevented from affecting other structures in the accommodating space when moving.

In a more specific embodiment, as shown in fig. 2, the first supporting structure includes a plurality of supporting pillars 22, which are disposed on the base 21 at intervals; the second support structure further includes a support member 23, which is located on the plurality of support columns 22 and is spaced from the base 21 in the height direction of the support columns 22; the pressing part 24 is movably disposed on the plurality of supporting pillars 22 and spaced from the supporting part 23 in the height direction of the supporting pillars 22, the pressing part 24 is disposed on one side of the supporting part 23 away from the base 21, when the impedance performance of the structure 90 to be tested is tested, the structure 90 to be tested is disposed between the supporting part 23 and the pressing part 24 and on the supporting part 23, the pressing part 24 is used for applying pressure to the structure 90 to be tested, and the pressure testing is disposed between the base 21 and the supporting part 23 and on the base 21. The structure is relatively simple, and at the same time, it can be ensured that the pressure detection device 50 can accurately detect the pressure applied by the pressure component 20 to the structure to be tested 90, thereby more accurately simulating the test pressure.

In order to control the pressing portion to move in a predetermined direction more conveniently and efficiently, in an embodiment of the present application, as shown in fig. 2, the pressing assembly 20 includes: and a transmission structure 25 connected to the first support structure for adjusting the movement of the pressing part 24 in a direction approaching or separating from the base 21.

In another embodiment of the present application, as shown in fig. 2, the environmental parameter adjustment assembly 30 includes a heating device 31, a humidifying device 32, and an air exhausting device 33, wherein the heating device 31 is located in the accommodating space, and the heating device 31 is used for adjusting the temperature in the accommodating space; the humidifying device 32 is located in the accommodating space, and the humidifying device 32 is used for adjusting the humidity in the accommodating space; the air exhausting device 33 is communicated with the accommodating space, and the air exhausting device 33 is used for adjusting the humidity and humidity in the accommodating space. In this embodiment, the temperature and humidity in the accommodating space can be efficiently adjusted in real time by the three devices.

In a more specific embodiment, the humidifying device can control the humidity in the accommodating space to be between 1 and 95 percent RH; the heating equipment can control the temperature in the accommodating space between minus 40 ℃ and 180 ℃, and the temperature rising and reducing speed is adjustable between 1 ℃/min and 20 ℃/min; the air exhaust equipment can coordinate the temperature and humidity modules to quickly adjust the temperature and humidity after instructions are input, and has the function of maintaining the temperature and humidity in the accommodating space to be uniformly distributed;

in order to simulate the test temperature and the test humidity more accurately, in an embodiment of the present application, as shown in fig. 2, the impedance testing apparatus further includes: and a temperature and humidity detecting device 60 for detecting the temperature and humidity in the accommodating space.

In a specific embodiment, the temperature and humidity detecting device 60 includes a temperature sensor, a humidity sensor and a data converter, wherein a testing error of the temperature sensor is ± 0.1 ℃, and a testing error of the humidity sensor is ± 0.5% RH.

The pressure detection equipment is connected with the data converter through a wire outlet hole 11 of the box body to realize circuit connection.

In another embodiment of the present application, as shown in fig. 2, the impedance testing apparatus further includes: and a correcting device 70 electrically connected to the pressure detecting device 50 and/or the temperature/humidity detecting device 60, for correcting the pressure detecting device 50 and/or the temperature/humidity detecting device 60. The pressure detection device 50 and the temperature and humidity detection device 60 are corrected by the correction device 70, so that accurate detection of pressure, temperature and humidity is further ensured, thereby further ensuring that different environmental conditions are accurately simulated, and further ensuring the accuracy of the result of the impedance characteristic test.

In order to make the impedance testing apparatus work more efficiently, as shown in fig. 2, in an embodiment of the present application, the impedance testing apparatus further includes: and a processor 80 located outside the accommodating space, electrically connected to the impedance testing device 40 and the calibration device 70, respectively, and configured to control operations of the impedance testing device 40 and the calibration device 70.

In yet another embodiment of the present application, as shown in fig. 2, the test housing 10 has an outlet hole 11. The connecting line between the device inside the accommodating space and the device outside the accommodating space can be routed through the wire outlet hole 11, that is, the wire outlet hole 11 is used as a circuit channel, specifically, the connecting line between the pressure detection device 50 and the correction device 70 can be routed through the wire outlet hole 11, and the connecting line between the impedance test device 40 and the structure to be tested 90 can also be routed through the wire outlet hole 11.

In order to further guarantee that this accommodation space has good sealing performance when testing, in an embodiment of this application, above-mentioned through soft silica gel circle, fill at wire hole and pencil, realize sealed accommodation space's effect.

In order to further ensure that the receiving space can stably maintain the corresponding environmental parameters within the testing time period after the testing environmental parameters are adjusted, and further ensure the accuracy of the testing result, in an embodiment of the present application, the testing housing 10 is a constant temperature and humidity chamber. In a more specific embodiment, the box body is an explosion-proof high-temperature-resistant sheet metal box body, and as shown in fig. 2, the box body further includes a box door 12 and a door handle disposed on the box door 12.

The impedance test equipment comprises an alternating current impedance test system and a direct current impedance test system, and is suitable for testing the impedance characteristics of various battery units.

In order to further guarantee under various environmental parameters, the normal clear of test, the outer cladding of connecting wire in this application has insulating glue, can test under the high humidity condition, and the short circuit condition does not take place.

The specific test process of the impedance test device comprises the following steps:

1) judging a structure to be tested, if the structure to be tested is a lithium battery, directly testing the structure to be tested, specifically comprising a symmetrical battery, a soft package battery, an aluminum shell battery, a full battery, a button battery, a cylindrical battery, a blade battery and the like, and directly using the battery for impedance testing, wherein when the structure to be tested is a battery finished product, no specific requirements are imposed on materials such as positive and negative electrode materials, a diaphragm, electrolyte, a binder and the like of the battery;

2) if the structure to be tested is a lithium battery material and comprises a positive electrode material, a negative electrode material, a diaphragm, electrolyte and a binder, preparing a suitable battery type, testing the impedance value of the lithium battery material, for example, testing the impedance value of the diaphragm, preparing a symmetrical battery by adopting copper foil, and measuring the impedance value of the diaphragm by controlling the layer number of the diaphragm in the symmetrical battery; for example, the impedance test of the anode material can adopt a lithium metal foil to prepare a button cell, and the impedance characteristic of the anode material is tested; impedance testing of other lithium battery materials, the utility model is not described in detail;

3) according to the test conditions, if the impedance characteristics under the conditions of constant temperature, pressure and humidity are tested, the test temperature and humidity of the accommodating space are set in advance to be stable;

4) placing the structure to be tested on a pressure assembly, applying a preset pressure, moving the pressure assembly, a pressure detection device and the structure to be tested into a containing space, and stabilizing for 5-10 minutes;

5) starting impedance test equipment, judging an adopted impedance test mode, if the impedance test mode is an alternating current impedance test mode, enabling the impedance test equipment to output disturbance current for testing, and executing disturbance frequency according to test requirements; if the direct current impedance test is carried out, the impedance test equipment outputs pulse current to carry out the test, and the test current is adjusted according to the structure to be tested, wherein the alternating current impedance method is a known test method in the prior art. The direct current impedance test method is also a method for quickly and accurately measuring the internal resistance of the lithium battery, the voltage drop on the battery is measured by applying instant current to the battery for discharging, and the current internal resistance of the battery is calculated through ohm's law;

6) outputting the impedance value of the lithium battery or lithium battery material under the conditions of set temperature, pressure and humidity; if the characteristics of the impedance value changing along with the pressure, the temperature and the humidity need to be tested on line, the impedance value of the lithium battery or the lithium battery material can be recorded in real time;

7) according to the test conditions, if the impedance characteristics under the condition of multi-factor (including temperature, pressure and humidity) change are tested, the pre-starting conditions (pressure value, temperature value and humidity value) are set firstly; then moving the pressure equipment, the pressure detection equipment and the structure to be tested (the structure to be tested) into the accommodating space; selecting a proper impedance test mode, and starting record tests of impedance data, temperature values, pressure values and humidity values; the temperature, pressure and humidity values are changed, and impedance characteristics under different external conditions are recorded and observed.

In the description of the present application, it is to be understood that the terms "at", "through", "rotation", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, which are merely for convenience of describing the present invention and simplifying the description process, and do not limit the apparatus or device to which the present invention refers to necessarily be configured in a specific orientation, and thus, should not be construed as limiting the present invention. In addition, in the description of the present invention, it should be noted that the terms "connect", "install", and the like are to be understood in a broad sense, for example, the connection between the calibration device and the pressure sensor and the temperature and humidity detection device through two circuit lines may be a fixed connection, a detachable connection, or an indirect connection through an intermediary.

In order to make those skilled in the art more detailed understand the technical solution of the present application, the technical solution of the present application will be described below with reference to specific embodiments.

Example 1

Referring to fig. 2, the impedance testing apparatus includes a testing housing 10, a pressure assembly 20, an environmental parameter adjusting assembly 30, an impedance testing device 40, a pressure detecting device 50, a temperature and humidity detecting device 60, a correcting device 70, and a processor 80. The testing shell 10 is a constant temperature and humidity box, the environmental parameter adjusting component 30 comprises a humidity control module, a heating module and an exhaust module, and the constant temperature and humidity box comprises an outlet hole 11 and a box door 12; the pressure assembly 20 comprises a base 21, a transmission structure 25, a support column 22, a support 23 and a pressing part 24; the pressure detecting device 50 is a pressure sensor. The correction device 70 is electrically connected with the pressure sensor through the wire outlet hole 11, and is connected with the temperature and humidity detection device 60 through another circuit; the impedance testing device 40 is connected to the structure to be tested 90 through the wire outlet hole 11; the processor 80 described above is connected to the calibration device 70 and the impedance testing device 40 by a circuit.

The temperature of the constant temperature and humidity box is set to be 20 ℃, the humidity is set to be 40RH percent, and the constant temperature and humidity box is stabilized for a period of time after the temperature and the humidity reach set values. A lithium iron phosphate battery (50% SOC) was placed on the surface of the support 23 of the pressure assembly 20, a pressure sensor was placed between the support 23 and the base 21, and a test pressure value of 100kgf was adjusted by the driving structure 25. And moving the pressure component 20, the pressure sensor and the structure to be tested 90 into a constant temperature and humidity box body, and stabilizing for 10 minutes. And starting a direct current impedance testing system of the impedance testing equipment 40, testing the direct current internal resistance of the lithium battery, and recording the testing temperature, humidity, pressure and direct current impedance value at the moment. The test temperatures were changed to 30 ℃, 40 ℃, and 50 ℃, respectively, the impedance characteristics of the lithium iron phosphate at different temperatures were recorded, and the final test results were output, as shown in table 1.

Example 2

The impedance test apparatus was the same as that of example 1, and the test procedure included:

the temperature of the constant temperature and humidity box is set to be 25 ℃, the humidity is set to be 50RH percent, and after the temperature and the humidity reach set values, the temperature and the humidity are stabilized for a period of time. A ternary lithium battery (50% SOC) was placed on the surface of the support 23 of the pressure assembly 20, the pressure sensor was placed between the support 23 and the base 21, and the test pressure value was adjusted to 1kgf by the driving structure 25. And moving the pressure component 20, the pressure sensor and the structure to be tested 90 into a constant temperature and humidity box body, and stabilizing for 10 minutes. And starting a direct current impedance testing system of the impedance testing equipment 40, testing the direct current internal resistance of the lithium battery, and recording the testing temperature, humidity, pressure and direct current impedance value at the moment. And opening the constant temperature and pressure box door 12, adjusting the transmission structure 25 of the pressure assembly 20, setting the pressure values to 10kgf, 400kgf and 800kgf respectively, and recording the impedance characteristics of the ternary lithium battery under different pressures to obtain the test results, which are shown in table 2.

Example 3

selecting a PE diaphragm with the area of 4cm multiplied by 5cm, and controlling the number of layers of the diaphragm to be 0, 1, 2 and 3 respectively to prepare the symmetrical battery. The temperature of the constant temperature and humidity box is set to be 20 ℃, the humidity is set to be 20 RH%, and after the temperature and the humidity reach set values, the temperature and the humidity are stabilized for a period of time. The symmetrical battery is placed on the surface of the support 23 of the pressure assembly 20, the pressure sensor is placed between the support 23 and the base 21, and the test pressure value is adjusted to 50kgf by the transmission structure 25. And moving the pressure component 20, the pressure sensor and the structure to be tested 90 into a constant temperature and humidity box body, and stabilizing for 10 minutes. And starting the alternating current impedance testing system of the impedance testing equipment 40, and recording the impedance value of the symmetrical battery. Opening the constant temperature and pressure chamber door 12, adjusting the transmission structure 25 of the pressure assembly 20, setting the pressure values to 150kgf, 200kgf and 300kgf, respectively, recording the impedance characteristics of the diaphragm under different pressures, and obtaining the test result, see table 3, where fig. 3 is an ohmic impedance test curve of embodiment 3, where the abscissa is real impedance and the ordinate is imaginary impedance.

TABLE 1

TABLE 2

TABLE 3

From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:

the impedance testing device comprises a testing shell and an environmental parameter adjusting component, wherein the temperature and/or the humidity of an accommodating space of the testing shell are adjusted through the environmental parameter adjusting component to simulate different climatic conditions, so that different testing conditions are met, the impedance performance of a lithium battery or a related structure (a structure to be tested) under different climatic conditions is tested, the problem that the impedance characteristics of the lithium battery or the related structure under different climatic conditions are difficult to test in the scheme in the prior art is solved, the service life and the safety evaluation of lithium batteries and lithium battery materials in practical application can be realized, and effective experimental basis is provided; the specific test result can also be used for effectively evaluating the failure aging mechanism process of the lithium battery and the lithium battery material, and promoting the development of the field of the lithium battery.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An impedance testing device, comprising:

a test housing having an accommodation space;

the pressure assembly is positioned in the containing space and is used for applying pressure to a structure to be tested;

the environment parameter adjusting assembly is positioned in the accommodating space and is used for adjusting the temperature and/or humidity in the accommodating space;

and the impedance testing equipment is positioned outside the testing shell and is used for being electrically connected with the structure to be tested so as to test the impedance performance of the structure to be tested.

2. The impedance testing device of claim 1, further comprising:

and the pressure detection equipment is positioned in the accommodating space and is used for detecting the pressure applied to the structure to be tested by the pressure component.

3. The impedance testing device of claim 2, wherein the pressure assembly comprises:

the base is positioned on the bottom surface of the accommodating space;

a first support structure located on the base;

and the second support structure comprises a pressing part, and the pressing part is movably arranged on the first support structure along the direction close to the base so as to apply pressure to the structure to be tested, which is arranged between the pressing part and the base.

4. Impedance testing device according to claim 3,

the first support structure includes: the supporting columns are arranged on the base at intervals;

the second support structure further comprises: the supporting pieces are positioned on the supporting columns and are arranged at intervals with the base in the height direction of the supporting columns;

the pressing part is movably arranged on the support columns and is arranged at intervals with the support piece in the height direction of the support columns, the pressing part is arranged on one side, far away from the base, of the support piece, and when impedance performance detection is carried out on the structure to be tested, the structure to be tested is arranged between the support piece and the pressing part and is arranged on the support piece;

the pressure detection device is located between the base and the supporting piece and located on the base.

5. The impedance testing device of claim 3, wherein the pressure assembly comprises:

and the transmission structure is connected with the first support structure and used for adjusting the pressing part to move along the direction close to or far away from the base.

6. The impedance testing device of any one of claims 1 to 5, wherein the environmental parameter adjustment assembly comprises:

the heating device is positioned in the accommodating space and used for adjusting the temperature in the accommodating space;

the humidifying equipment is positioned in the accommodating space and used for adjusting the humidity in the accommodating space;

and the air exhaust equipment is communicated with the accommodating space and is used for adjusting the humidity and humidity in the accommodating space.

7. The impedance testing device according to any one of claims 2 to 5, further comprising:

and the temperature and humidity detection equipment is used for testing the temperature and the humidity in the accommodating space.

8. The impedance testing device of claim 7, further comprising:

and the correcting equipment is electrically connected with the pressure detection equipment and/or the temperature and humidity detection equipment and is used for correcting the pressure detection equipment and/or the temperature and humidity detection equipment.

9. The impedance testing device of any one of claims 1 to 5, wherein the test housing has an outlet aperture.

10. The impedance testing device of any one of claims 1 to 5, wherein the test housing is a constant temperature and humidity chamber.