Secondary battery in-situ detection device and method
By using a precision three-dimensional moving platform and a synchronous signal control system, combined with a high-transmittance optical window and a liquid nitrogen-cooled detector, the problems of insufficient spatial resolution and signal interference in in-situ detection of secondary batteries were solved, and high-sensitivity analysis of the electrode-electrolyte interface was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-12
AI Technical Summary
Existing in-situ detection technologies for secondary batteries suffer from insufficient spatial resolution, severe interference from bulk electrolyte signals, and poor instrument compatibility, making it difficult to accurately locate and analyze the electrode-electrolyte interface reaction process.
Employing a precision three-dimensional moving platform and a synchronous signal control system, combined with a Fourier transform micro-infrared spectrometer and an electrochemical workstation, the battery is tightly fixed and flexibly adjusted through components such as limiting clamps and torsion springs. With a high-transmittance optical window and a liquid nitrogen-cooled mercury-cadmium-tellurium detector, the system achieves synchronous acquisition of spectral data and electrochemical data, accurately capturing the dynamic reaction at the electrode-electrolyte interface.
This technology enables highly sensitive qualitative and quantitative analysis of the electrode-electrolyte interface, improving the accuracy and reliability of detection results and solving the problems of insufficient micro-area localization accuracy and signal interference in existing technologies.
Smart Images
Figure CN122016697A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of secondary battery testing technology, specifically to a secondary battery in-situ testing device and method. Background Technology
[0002] The core performance characteristics of rechargeable batteries, such as cycle life, safety, and rate capability, are closely related to the structural stability of electrode materials and the evolution of the electrode-electrolyte interface during cycling. The electrode-electrolyte interface includes the cathode-electrolyte interface (CEI) and the solid electrolyte interphase (SEI). Therefore, a thorough understanding of the complex and dynamic reaction processes at the electrode-electrolyte interface is a key technological support for the development of next-generation high-performance rechargeable batteries.
[0003] Currently, most characterization methods for electrode materials in secondary batteries employ non-in-situ offline testing. These methods require disassembling the battery after it has completed a specified number of cycles, followed by subsequent testing and analysis of the disassembled electrode materials. Such methods cannot capture intermediate state information during the electrode-electrolyte interface reaction process, and the battery disassembly process can easily alter or even destroy the original interface state, leading to discrepancies between the final test and analysis results and the actual situation.
[0004] In recent years, in-situ spectroscopic characterization techniques have been widely used in the field of secondary battery detection, with in-situ Raman spectroscopy and in-situ X-ray diffraction being typical examples. Fourier transform infrared spectroscopy possesses unique advantages in detecting polar functional groups and molecular bond vibration information of organic and inorganic components. It can be effectively applied to the study of the decomposition process of organic electrolytes and electrolyte anions, as well as the analysis of the formation and evolution mechanisms of key components such as lithium oxide, lithium fluoride, and various organic compounds in SEI and CEI films. However, existing in-situ detection technologies for secondary batteries based on Fourier transform infrared spectroscopy still have many technical problems that urgently need to be solved, specifically in the following three aspects: First, insufficient spatial resolution; conventional transmission mode and attenuated total reflection mode are difficult to accurately locate and specifically analyze specific micro-regions such as individual active particles and cracks on the electrode surface. Second, strong interference from bulk electrolyte signals; a large amount of bulk electrolyte has a strong absorption effect on infrared light, which seriously interferes with the effective acquisition of weak signals at the electrode-electrolyte interface. Third, poor compatibility between in-situ batteries and detection instruments; most existing simple in-situ batteries cannot achieve good matching with the optical path and sample stage of Fourier transform infrared microscopy, and it is also difficult to maintain stable and reliable sealing and electrical contact performance during long-term electrochemical testing.
[0005] Furthermore, in practical applications, batteries often need to be tightly fixed during alignment to avoid deviations. Once the lens of the Fourier transform micro-infrared spectrometer is aligned with the battery and testing can begin, the battery also needs to have a certain degree of flexibility to adapt to the actual testing requirements. However, existing technologies often compromise on this aspect, either only allowing for fixation or completely abandoning fixation, resulting in poor applicability in actual operation.
[0006] In summary, the present invention provides an in-situ detection device and method for secondary batteries to solve the above-mentioned problems. Summary of the Invention
[0007] This invention provides an in-situ detection device and method for secondary batteries. It achieves strict time synchronization between spectral acquisition and electrochemical data through a synchronous signal control system. Combined with the precise micro-area positioning function of a precision three-dimensional moving platform and the optimized structural design of the in-situ battery, it solves the problems in the prior art where the lack of strict time synchronization between spectral acquisition and electrochemical data, insufficient micro-area positioning accuracy, leads to lag in dynamic process monitoring and difficulty in characterizing the spatial non-uniformity of interface reactions.
[0008] The specific technical solution of the present invention is as follows: a secondary battery in-situ detection device, comprising an in-situ battery, a precision three-dimensional moving platform disposed below the in-situ battery, a Fourier transform micro-infrared spectrometer disposed above the in-situ battery, an electrochemical workstation disposed on one side of the Fourier transform micro-infrared spectrometer, and a synchronization signal control system disposed on the other side of the Fourier transform micro-infrared spectrometer, the synchronization signal control system being connected to the Fourier transform micro-infrared spectrometer and the electrochemical workstation respectively;
[0009] A mounting base is provided between the precision three-dimensional moving platform and the in-situ battery. The bottom of the mounting base is connected to the precision three-dimensional moving platform. A limiting clamp is rotatably connected to the top of the mounting base. A torsion spring is fixedly connected to one side of the limiting clamp. The end of the torsion spring away from the limiting clamp is connected to the mounting base. An adjusting frame is fixedly connected to the top of the mounting base. A transmission cover is slidably connected to the middle of the adjusting frame. A compression spring is fixedly connected to the bottom of the transmission cover. The bottom of the compression spring is connected to the adjusting frame. A limiting frame is provided on the outside of the compression spring. A displacement spring is fixedly connected to the outside of the limiting frame. A transmission column is fixedly connected to the end of the displacement spring away from the limiting frame. A displacement spring plate is fixedly connected to the top of the transmission column. A limiting slot is opened on the side of the limiting frame near the displacement spring plate. One side of the transmission column is slidably connected to the limiting frame. A limiting block is provided on the side of the transmission column away from the limiting frame. A clamping spring is fixedly connected to one side of the limiting block. The side of the limiting block away from the clamping spring is rotatably connected to the adjusting frame.
[0010] In this invention, when it is necessary to tightly fix the in-situ battery on a precision three-dimensional moving platform, it is only necessary to rotate the limiting clamp to compress the torsion spring, and finally push the limiting clamp into the limiting clamp block, so that the limiting clamp is clamped and fixed by the limiting clamp block. Multiple sets of limiting clamps can be used to fix the in-situ battery.
[0011] In this invention, when the operator needs the battery in its original position to have a certain amount of room to move and make adjustments, it is only necessary to apply downward pressure to the transmission cover, so that the compression spring is compressed and the pressure is transmitted to the top of the shifting spring, causing the top of the shifting spring to disengage from the limiting slot. At this time, the shifting spring naturally extends and applies a pushing force away from the limiting frame to the transmission column. The transmission column transmits the pushing force to the side of the limiting clamp, causing the limiting clamp to rotate under force. Finally, the limiting clamp releases the limiting clamp from the limiting plate, and the torsion spring naturally resets and applies rotational force to the limiting clamp, causing the limiting clamp to return to its initial position and release the restriction on the battery in its original position.
[0012] As an improvement of the present invention, the in-situ battery includes a top cover, which is disposed below a Fourier transform micro-infrared spectrometer. An optical window is embedded in the center of the top cover. A first conductive metal sheet is disposed below the top cover. A hollow intermediate support is disposed below the first conductive metal sheet. A working electrode is disposed at the center of the intermediate support. A diaphragm is disposed below the working electrode. A counter electrode is disposed below the diaphragm. A spring boss is disposed below the counter electrode. A spring is disposed on the side of the spring boss. A second conductive metal sheet is disposed below the intermediate support. The upper part of the second conductive metal sheet is attached to the bottom end of the spring. A base is disposed below the second conductive metal sheet.
[0013] As an improvement of the present invention, the Fourier transform micro-infrared spectrometer is equipped with a liquid nitrogen-cooled mercury-cadmium-tellurium detector to obtain a highly sensitive infrared signal.
[0014] As an improvement of the present invention, the material of the optical window has high transmittance for mid-infrared light.
[0015] As an improvement of the present invention, the middle part of the intermediate support forms a thin-layer cavity for containing a trace amount of electrolyte, and the thickness of the thin-layer cavity is adjusted by a spring boss, with a value between 150μm and 200μm.
[0016] As an improvement of the present invention, an assisting block is provided above the limiting clamp, the assisting block is fixedly connected to the mounting base, and a groove adapted to the assisting block is provided at the bottom of the limiting clamp.
[0017] A method for in-situ detection of secondary batteries includes the following steps:
[0018] S1. Assemble the in-situ battery and adjust the cavity thickness to 150~200μm by using the spring boss and spring in coordination.
[0019] S2. Install the in-situ battery onto the precision three-dimensional moving platform with the optical window facing upward. Then move the working electrode target micro-area of the in-situ battery to the infrared spot focusing area, fine-tune and optimize the optical coupling effect, and establish a stable electrical circuit between the first and second conductive metal sheets and the electrochemical workstation through electrical leads.
[0020] S3. Configure the electrochemical charge-discharge program in the synchronous signal control system and set the test parameters of the Fourier transform micro-infrared spectrometer.
[0021] S4. Start the test program. The electrochemical workstation outputs charge and discharge commands to drive the redox reaction at the electrode-electrolyte interface of the in-situ battery and capture the infrared signal at the electrode-electrolyte interface.
[0022] S5. After the test, integrate the test data, analyze the intensity changes, peak position shifts and peak shape evolution of the infrared characteristic peaks, and combine them with the electrochemical response law to qualitatively analyze the test results.
[0023] As an improvement of the present invention, the electrochemical charge-discharge program adopts the intermittent relaxation test method, and sets a 10-30s resting step between adjacent charge-discharge pulses. The spectral acquisition trigger condition is set to be triggered during the resting stage. By resting, the ohmic polarization effect is eliminated or reduced, and the stability and detection accuracy of the infrared spectral signal are improved.
[0024] In this invention, the synchronization signal control system adopts a primary and secondary redundant trigger design. The primary synchronization signal is generated by the CPU interrupt triggered by the charge and discharge data frame output by the electrochemical workstation. The secondary synchronization signal is backed up by a timer. When the primary signal fails due to abnormal data transmission, the secondary signal can be switched in place immediately to ensure that the timing synchronization error between spectral acquisition and electrochemical testing is controlled within the millisecond level, and to accurately capture the intermediate state of dynamic reaction at the electrode interface.
[0025] In this invention, the synchronization signal control system can also be a commonly used system in the prior art, such as the in-situ-working condition characterization platform of Xiamen University.
[0026] In this invention, the precision three-dimensional moving platform adopts an orthogonal modular design, with bidirectional repeatability of ±1μm on the X and Y axes and positioning accuracy of ±0.3μm / 1mm on the Z axis. It supports nanometer-level step size adjustment and can drive the in-situ battery to achieve precise scanning of the micro-area on the electrode surface. It can specifically characterize the heterogeneity of interface reaction in different regions and solve the problem that existing technologies cannot capture spatial non-uniformity.
[0027] In this invention, the optical window is preferably made of CaF2, ZnSe or AlON transparent ceramic material. Among them, 1mm thick AlON transparent ceramic has a transmittance of ≥85% in the mid-infrared band (3~5μm), and has excellent mechanical strength and chemical stability. It can ensure that infrared light can penetrate efficiently and reach the surface of the working electrode, and can also meet the sealing structure requirements of the in-situ battery, avoiding electrolyte leakage due to window damage during the test.
[0028] In this invention, a polytetrafluoroethylene (PTFE) gasket is sandwiched between the top cover and the base of the in-situ battery and arranged around the periphery of the intermediate support. The surface contact is pressed together by the fastening pressure of the top cover and the base, which can effectively prevent the electrolyte from leaking from the shell joint, ensuring the sealing during long-term in-situ testing. At the same time, its chemical inertness will not react with the electrolyte, avoiding contamination of the testing system.
[0029] In this invention, the thickness of the thin cavity in the middle of the intermediate support is specifically set to 150μm to 200μm. This thickness can accommodate a sufficient amount of trace electrolyte to meet the battery charging and discharging requirements, while minimizing the absorption interference of the electrolyte relative to the infrared signal. With the synergistic effect of the spring boss and the side spring, the spring provides vertical elastic force and the boss guides and limits the position, ensuring that the electrode and the separator are tightly attached and the cavity thickness is uniform, which significantly improves the signal-to-noise ratio of the infrared signal of the interface reaction.
[0030] In this invention, both the first and second conductive metal sheets are made of highly conductive inert metal materials, which not only provide a stable current transmission channel for the working electrode and the counter electrode, but also achieve uniform current distribution through planar contact, avoiding abnormal electrode reactions caused by local current concentration. At the same time, the rigid structure of the metal sheets can effectively support the intermediate support body, spring boss and other components, ensuring the stability of the overall structure of the in-situ battery.
[0031] In this invention, the liquid nitrogen-cooled mercury cadmium tellurium (MCT) detector exhibits excellent infrared response performance, with a detectivity D* > 2.5 × 10⁻⁶. 9 With a response time of <3ns, it can accurately capture weak infrared signals generated during processes such as the evolution of the SEI film at the electrode interface and the degradation of the electrolyte. Combined with the high resolution advantage of the Fourier transform micro-infrared spectrometer, it can achieve highly sensitive qualitative and quantitative analysis of microscopic reaction processes.
[0032] In this invention, the data acquisition system can be a system commonly used in the prior art, such as the CHI600F dual-channel 16-bit resolution synchronous data acquisition system; the control software can be software commonly used in the prior art, such as PalmSens' PSTrace.
[0033] Compared with the prior art, the present invention has the following beneficial effects:
[0034] 1. This invention achieves tight fixation during the in-situ battery alignment stage and flexible adjustment during the testing stage through a fixed and unlocking linkage structure composed of components such as the upper limit clamping plate, torsion spring, and displacement spring on the mounting base. Combined with the nanoscale micro-area positioning function of the precision three-dimensional moving platform and the millisecond-level timing synchronization mechanism of the synchronous signal control system, it effectively solves the problems of inconsistency between fixation and adjustment, insufficient micro-area positioning accuracy, and asynchrony between spectral and electrochemical data in the prior art, and accurately captures the dynamic reaction intermediate state and spatial non-uniformity of the electrode-electrolyte interface.
[0035] 2. This invention, through the in-situ PTFE gasket sealing structure of the battery, the 150~200μm thin-layer cavity design, and the selection of a high-transmittance optical window, combined with the liquid nitrogen-cooled mercury-cadmium-tellurium detector of the Fourier transform micro-infrared spectrometer, not only minimizes the infrared signal interference from the bulk electrolyte, but also ensures the sealing and structural stability of long-term testing, significantly improves the acquisition quality of weak interface signals, realizes high-sensitivity qualitative and quantitative analysis of the component and structural evolution of the secondary battery interface reaction, and improves the accuracy and reliability of the detection results. Attached Figure Description
[0036] Figure 1 This is a schematic diagram of the overall structure of the present invention.
[0037] Figure 2 This is a schematic diagram of the electrochemical workstation of the present invention.
[0038] Figure 3 The present invention is a Fourier transform micro-infrared spectrometer.
[0039] Figure 4 This is a schematic diagram of the top cover of the present invention.
[0040] Figure 5 This is a schematic diagram of the optical window of the present invention.
[0041] Figure 6 This is a schematic diagram of the first conductive metal sheet of the present invention.
[0042] Figure 7 This is a schematic diagram of the intermediate support body of the present invention.
[0043] Figure 8 This is a schematic diagram of the working electrode of the present invention.
[0044] Figure 9 This is a schematic diagram of the diaphragm of the present invention.
[0045] Figure 10 This is a schematic diagram of the second conductive metal sheet of the present invention.
[0046] Figure 11 This is a schematic diagram of the base of the present invention.
[0047] Figure 12 This is a schematic diagram of the test results of an embodiment of the present invention.
[0048] Figure 13 This is a schematic diagram of the test results of the control group in an embodiment of the present invention.
[0049] Figure 14 This is a schematic diagram of the mounting base of the present invention.
[0050] Figure 15 This is a schematic diagram of the limiting clamp of the present invention.
[0051] Figure 16 This is a schematic diagram of the transmission cover of the present invention.
[0052] Figure 17 This is a schematic diagram of the compression spring of the present invention.
[0053] Figure 18 This is a schematic diagram of the limiting frame of the present invention.
[0054] Figure 19 This is a schematic diagram of the transmission column of the present invention.
[0055] The attached figures are labeled as follows: 1. In-situ battery; 2. Precision three-dimensional moving platform; 3. Fourier transform micro-infrared spectrometer; 4. Electrochemical workstation; 5. Top cover; 6. Optical window; 7. First conductive metal sheet; 8. Intermediate support; 9. Working electrode; 10. Diaphragm; 11. Counter electrode; 12. Spring boss; 13. Spring; 14. Second conductive metal sheet; 15. Base; 16. Synchronous signal control system; 201. Mounting base; 202. Limiting clamp; 203. Torsion spring; 204. Assist block; 205. Adjustment frame; 206. Transmission cover; 207. Compression spring; 208. Limiting frame; 209. Repositioning spring; 210. Transmission column; 211. Repositioning spring; 212. Limiting slot; 213. Limiting clamp; 214. Clamping spring. Detailed Implementation
[0056] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.
[0057] like Figure 1-19As shown, the present invention provides an in-situ detection device for secondary batteries based on a Fourier transform micro-infrared spectrometer, including an in-situ battery 1, a precision three-dimensional moving platform 2 disposed below the in-situ battery 1, a Fourier transform micro-infrared spectrometer 3 disposed above the in-situ battery 1, an electrochemical workstation 4 disposed on one side of the Fourier transform micro-infrared spectrometer 3, and a synchronization signal control system 16 disposed on the other side of the Fourier transform micro-infrared spectrometer 3. The synchronization signal control system 16 is connected to the Fourier transform micro-infrared spectrometer 3 and the electrochemical workstation 4 respectively.
[0058] The in-situ battery 1 includes an upper cover 5, which is positioned below the Fourier transform micro-infrared spectrometer 3. An optical window 6 is embedded in the center of the upper cover 5. A first conductive metal sheet 7 is positioned below the upper cover 5. A hollow intermediate support 8 is positioned below the first conductive metal sheet 7. A working electrode 9 is positioned at the center of the intermediate support 8. A diaphragm 10 is positioned below the working electrode 9. A counter electrode 11 is positioned below the diaphragm 10. A spring boss 12 is positioned below the counter electrode 11. A spring 13 is positioned on the side of the spring boss 12. A second conductive metal sheet 14 is positioned below the intermediate support 8. The upper part of the second conductive metal sheet 14 is attached to the bottom end of the spring 13. A base 15 is positioned below the second conductive metal sheet 14.
[0059] The in-situ battery 1 is provided with a polytetrafluoroethylene gasket to improve sealing.
[0060] The Fourier transform micro-infrared spectrometer 3 is equipped with a liquid nitrogen-cooled mercury-cadmium-tellurium detector to obtain highly sensitive infrared signals.
[0061] The material of the optical window 6 has high transmittance for mid-infrared light.
[0062] The middle part of the intermediate support 8 forms a thin cavity for containing a small amount of electrolyte. The thickness of the thin cavity is adjusted by the spring boss 12, and the value is between 150μm and 200μm.
[0063] The electrochemical workstation 4 includes a potentiostat, a signal generator, a data acquisition system, and control software.
[0064] A method for in-situ detection of secondary batteries includes the following steps:
[0065] S1. Assemble the in-situ battery and adjust the cavity thickness to 150~200μm by using the spring boss and spring in coordination.
[0066] S2. Install the in-situ battery onto the precision three-dimensional moving platform with the optical window facing upward. Then move the working electrode target micro-area of the in-situ battery to the infrared spot focusing area, fine-tune and optimize the optical coupling effect, and establish a stable electrical circuit between the first and second conductive metal sheets and the electrochemical workstation through electrical leads.
[0067] S3. Configure the electrochemical charge-discharge program in the synchronous signal control system and set the test parameters of the Fourier transform micro-infrared spectrometer.
[0068] S4. Start the test program. The electrochemical workstation outputs charge and discharge commands to drive the redox reaction at the electrode-electrolyte interface of the in-situ battery and capture the infrared signal at the electrode-electrolyte interface.
[0069] S5. After the test, integrate the test data, analyze the intensity changes, peak position shifts and peak shape evolution of the infrared characteristic peaks, and combine them with the electrochemical response law to qualitatively analyze the test results.
[0070] The electrochemical charge-discharge program uses the intermittent relaxation test method, with a 10-30s resting step between adjacent charge-discharge pulses, and the spectral acquisition trigger condition is set to be triggered during the resting stage.
[0071] Example: Figure 1-19 As shown, to verify the in-situ, dynamic, and micro-area detection performance of this device on the evolution of electrolyte and dynamic changes of interface reaction on the working electrode surface during the charge-discharge cycle of a secondary battery, and to compare the influence of different types of separators on the battery interface reaction characteristics, the following experiments were conducted.
[0072] The experiment used Cu foil as the working electrode, which was set in close contact with the CaF2 window, and Zn foil as the counter electrode. The electrolyte was a 2M ZnSO4 aqueous solution. The separator in the experimental group was a ferroelectric composite separator coated with ferroelectric material and polarized by an electric field, while the separator in the control group was a common glass fiber separator. The dimensions of both separators were adapted to the internal cavity of the in-situ battery support.
[0073] The equipment used in the experiment included the in-situ battery described in this invention, a precision three-dimensional moving platform with orthogonal modular design, a Fourier transform micro-infrared spectrometer equipped with a liquid nitrogen-cooled mercury-cadmium-tellurium detector, an electrochemical workstation including a potentiostat, a signal generator, a data acquisition system and control software, and a synchronous signal control system.
[0074] During the experiment, the in-situ battery was first assembled in a top-down order. Then, a trace amount of 2M ZnSO4 aqueous solution was injected into the thin-layer cavity to ensure complete electrolyte wetting of the separator without any residual air bubbles. Next, the assembled in-situ battery was fixed on a precision three-dimensional moving platform. The platform position was adjusted so that the center region of the working electrode was aligned with the focal point of the infrared spot on the Fourier transform infrared spectrometer. Fine-tuning was performed to maximize the spectral signal intensity. The electrochemical workstation was connected to the first and second conductive metal sheets via electrical leads to establish an electrical conduction circuit between the working electrode and the counter electrode. The synchronization signal control system was activated to complete signal pairing with the Fourier transform infrared spectrometer and the electrochemical workstation, and infrared spectral acquisition was started synchronously.
[0075] The electrochemical workstation's charge / discharge program was then initiated, discharging the battery with a constant current of 1 mA / cm² for 1 hour. After discharge, the battery was recharged with a constant current of 1 mA / cm² until the potential difference between the two electrodes was ≥0.6V, completing one charge / discharge cycle. At the start of charge / discharge and every 100 seconds thereafter, the synchronous signal control system triggered a Fourier transform infrared microscopy spectrometer to acquire the infrared microscopy signal on the working electrode surface. After the experiment, the synchronous signal control system correlated and integrated the acquired infrared spectral data with the voltage and current data recorded by the electrochemical workstation according to timestamps, analyzing the changes in the intensity and position of infrared characteristic peaks at different times, and comparing the differences in interfacial reactions between the two sets of experiments at each stage of charge / discharge.
[0076] Experimental results are as follows Figure 12 and Figure 13 As shown, the black curve corresponds to the test data at the start of discharge, the red curve corresponds to the test data at the start of charging, and the blue curve corresponds to the test data at the end of charging.
[0077] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A secondary battery in-situ testing device, characterized in that, The system includes an in-situ battery (1), a precision three-dimensional moving platform (2) is provided below the in-situ battery (1), a Fourier transform micro-infrared spectrometer (3) is provided above the in-situ battery (1), an electrochemical workstation (4) is provided on one side of the Fourier transform micro-infrared spectrometer (3), and a synchronous signal control system (16) is provided on the other side of the Fourier transform micro-infrared spectrometer (3). The synchronous signal control system (16) is connected to the Fourier transform micro-infrared spectrometer (3) and the electrochemical workstation (4) respectively. A mounting base (201) is provided between the precision three-dimensional moving platform (2) and the in-situ battery (1). The bottom of the mounting base (201) is connected to the precision three-dimensional moving platform (2). A limiting clamp (202) is rotatably connected to the top of the mounting base (201). A torsion spring (203) is fixedly connected to one side of the limiting clamp (202). The end of the torsion spring (203) away from the limiting clamp (202) is connected to the mounting base (201). An adjusting frame (205) is fixedly connected to the top of the mounting base (201). A transmission cover (206) is slidably connected to the middle of the adjusting frame (205). A compression spring (207) is fixedly connected to the bottom of the transmission cover (206). The bottom of the compression spring (207) is connected to the adjusting frame (205). A limiting frame (208) is provided on the outside of 07), and a shifting spring (209) is fixedly connected to the outside of the limiting frame (208). A transmission column (210) is fixedly connected to the end of the shifting spring (209) away from the limiting frame (208). A shifting spring (211) is fixedly connected to the top of the transmission column (210). A limiting slot (212) is opened on the side of the limiting frame (208) near the shifting spring (211). One side of the transmission column (210) is slidably connected to the limiting frame (208). A limiting clamping block (213) is provided on the side of the transmission column (210) away from the limiting frame (208). A clamping spring (214) is fixedly connected to one side of the limiting clamping block (213). The side of the limiting clamping block (213) away from the clamping spring (214) is rotatably connected to the adjusting frame (205).
2. The secondary battery in-situ detection device according to claim 1, characterized in that, The in-situ battery (1) includes a top cover (5), which is located below the Fourier transform micro-infrared spectrometer (3). An optical window (6) is embedded in the center of the top cover (5). A first conductive metal sheet (7) is located below the top cover (5). A hollow intermediate support (8) is located below the first conductive metal sheet (7). A working electrode (9) is located at the center of the intermediate support (8). A diaphragm (10) is located below the working electrode (9). A counter electrode (11) is located below the diaphragm (10). A spring boss (12) is located below the counter electrode (11). A spring (13) is located on the side of the spring boss (12). A second conductive metal sheet (14) is located below the intermediate support (8). The top of the second conductive metal sheet (14) is attached to the bottom of the spring (13). A base (15) is located below the second conductive metal sheet (14).
3. The in-situ detection device for secondary batteries according to claim 1, characterized in that, The Fourier transform micro-infrared spectrometer (3) is equipped with a liquid nitrogen-cooled mercury-cadmium-tellurium detector to obtain highly sensitive infrared signals.
4. The secondary battery in-situ detection device according to claim 2, characterized in that, The material of the optical window (6) has high transmittance for mid-infrared light.
5. The in-situ detection device for secondary batteries according to claim 2, characterized in that, The middle part of the intermediate support (8) forms a thin cavity for containing a small amount of electrolyte. The thickness of the thin cavity is adjusted by the spring boss (12) and the value is between 150μm and 200μm.
6. The in-situ detection device for secondary batteries according to claim 1, characterized in that, A booster block (204) is provided above the limiting clamp (202), and the booster block (204) is fixedly connected to the mounting base (201). A groove adapted to the booster block (204) is provided at the bottom of the limiting clamp (202).
7. A method for in-situ detection of secondary batteries, characterized in that, Includes the following steps: S1. Assemble the in-situ battery and adjust the cavity thickness to 150~200μm by using the spring boss and spring in coordination. S2. Install the in-situ battery onto the precision three-dimensional moving platform with the optical window facing upward. Then move the working electrode target micro-area of the in-situ battery to the infrared spot focusing area, fine-tune and optimize the optical coupling effect, and establish a stable electrical circuit between the first and second conductive metal sheets and the electrochemical workstation through electrical leads. S3. Configure the electrochemical charge-discharge program in the synchronous signal control system and set the test parameters of the Fourier transform micro-infrared spectrometer. S4. Start the test program. The electrochemical workstation outputs charge and discharge commands to drive the redox reaction at the electrode-electrolyte interface of the in-situ battery and capture the infrared signal at the electrode-electrolyte interface. S5. After the test, integrate the test data, analyze the intensity changes, peak position shifts and peak shape evolution of the infrared characteristic peaks, and combine them with the electrochemical response law to qualitatively analyze the test results.
8. The in-situ detection method for secondary batteries according to claim 7, characterized in that, The electrochemical charge-discharge program uses the intermittent relaxation test method, with a 10-30s resting step between adjacent charge-discharge pulses, and the spectral acquisition trigger condition is set to be triggered during the resting stage.