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CN-122016697-A - Secondary battery in-situ detection device and method

CN122016697ACN 122016697 ACN122016697 ACN 122016697ACN-122016697-A

Abstract

The invention relates to the technical field of secondary battery detection, and provides a secondary battery in-situ detection device and method, comprising an in-situ battery, a precise three-dimensional moving platform, a Fourier transform micro infrared spectrometer and an electrochemical workstation, wherein the in-situ battery comprises an upper cover, an optical window, an intermediate support body, a working electrode and other parts, the micro-region positioning is realized through the three-dimensional mobile platform, the synchronization system ensures the time sequence synchronization of the spectrum and the electrochemical data, the mercury-cadmium-tellurium detector of the spectrometer captures weak infrared signals, the in-situ, dynamic and micro-region detection of the secondary battery interface reaction is finally realized, and the detection accuracy and reliability are effectively improved.

Inventors

  • ZHAO YIFAN
  • YANG ZHIQI
  • QIU YAYU
  • CHEN FANG

Assignees

  • 浙江大学

Dates

Publication Date
20260512
Application Date
20260130

Claims (8)

  1. 1. The secondary battery in-situ detection device is characterized by comprising an in-situ battery (1), wherein a precise three-dimensional moving platform (2) is arranged below the in-situ battery (1), a Fourier transform micro infrared spectrometer (3) is arranged above the in-situ battery (1), an electrochemical workstation (4) is arranged on one side of the Fourier transform micro infrared spectrometer (3), a synchronous signal control system (16) is arranged on the other side of the Fourier transform micro infrared spectrometer (3), and the synchronous signal control system (16) is respectively connected with the Fourier transform micro infrared spectrometer (3) and the electrochemical workstation (4) in a signal manner; An installation base (201) is arranged between the precise three-dimensional moving platform (2) and the in-situ battery (1), the bottom of the installation base (201) is connected with the precise three-dimensional moving platform (2), a limit clamping plate (202) is rotationally connected above the installation base (201), a torsion spring (203) is fixedly connected to one side of the limit clamping plate (202), one end of the torsion spring (203) away from the limit clamping plate (202) is connected with the installation base (201), the top of the installation base (201) is fixedly connected with an adjusting frame (205), the middle part of the adjusting frame (205) is slidably connected with a transmission cover (206), the lower part of the transmission cover (206) is fixedly connected with a compression spring (207), the bottom of the compression spring (207) is connected with the adjusting frame (205), a limit frame (208) is arranged on the outer side of the compression spring (207), a transmission post (210) is fixedly connected to one end of the limit frame (208) away from the torsion spring (209), a reed (211) is fixedly connected to one side of the transmission post (210), which is close to the limit frame (211), one side of transmission post (210) and spacing frame (208) sliding connection, one side that spacing frame (208) were kept away from to transmission post (210) is provided with spacing clamp splice (213), one side fixedly connected with clamp spring (214) of spacing clamp splice (213), one side that clamp spring (214) were kept away from to spacing clamp splice (213) is connected with adjusting frame (205) rotation.
  2. 2. The secondary battery in-situ detection device according to claim 1, wherein the in-situ battery (1) comprises an upper cover (5), the upper cover (5) is arranged 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 arranged below the upper cover (5), a hollow middle support body (8) is arranged below the first conductive metal sheet (7), a working electrode (9) is arranged at the center of the middle support body (8), a diaphragm (10) is arranged below the working electrode (9), a counter electrode (11) is arranged below the diaphragm (10), a spring boss (12) is arranged below the counter electrode (11), a spring (13) is arranged on the side surface of the spring boss (12), a second conductive metal sheet (14) is arranged below the middle support body (8), a working electrode (9) is arranged above the second conductive metal sheet (14) and a bottom end of the spring (13) is attached to the second conductive metal sheet (14), and a base (15) is arranged below the second conductive metal sheet (14).
  3. 3. The secondary battery in-situ detection device according to claim 1, characterized in that the fourier transform micro-infrared spectrometer (3) is configured with a liquid nitrogen cooled mercury-cadmium-tellurium detector to obtain a high sensitivity infrared signal.
  4. 4. The secondary battery in-situ detection device according to claim 2, wherein the material of the optical window (6) has high transmittance for mid-infrared light.
  5. 5. The secondary battery in-situ detection device according to claim 2, characterized in that the middle part of the intermediate support (8) constitutes a thin layer cavity containing a micro-electrolyte, the thickness of which is regulated by a spring boss (12) with a value between 150 μm and 200 μm.
  6. 6. The secondary battery in-situ detection device according to claim 1, wherein a power-assisted clamping block (204) is arranged above the limiting clamping plate (202), the power-assisted clamping block (204) is fixedly connected with the mounting base (201), and a groove which is adaptive to the power-assisted clamping block (204) is formed in the bottom of the limiting clamping plate (202).
  7. 7. The secondary battery in-situ detection method is characterized by comprising the following steps of: s1, assembling an in-situ battery, and adjusting the thickness of a cavity to 150-200 mu m through cooperation of a spring boss and a spring; S2, installing an in-situ battery on a precise three-dimensional moving platform with an optical window upwards, then moving a target micro-area of a working electrode of the in-situ battery to an infrared light spot focusing area, fine-tuning to optimize the optical coupling effect, and establishing a stable circuit between the first conductive metal sheet and the second conductive metal sheet and an electrochemical workstation through an electrical lead; s3, configuring an electrochemical charging and discharging program in a synchronous signal control system, and setting testing parameters of a Fourier transform micro infrared spectrometer; S4, starting a test program, outputting a charge and discharge instruction by an electrochemical workstation, driving an in-situ battery electrode-electrolyte interface to perform oxidation-reduction reaction, and capturing an electrode-electrolyte interface infrared signal; And S5, integrating test data after the test is finished, and qualitatively analyzing the detection result by analyzing the intensity change, peak position deviation and peak shape evolution of the infrared characteristic peak and combining with an electrochemical response rule.
  8. 8. The method for in-situ detection of a secondary battery according to claim 7, wherein the electrochemical charge-discharge procedure is performed by an intermittent relaxation test method, a 10-30 s rest step is provided between adjacent charge-discharge pulses, and a spectrum acquisition trigger condition is set as a rest stage trigger.

Description

Secondary battery in-situ detection device and method Technical Field The invention relates to the technical field of secondary battery detection, in particular to a secondary battery in-situ detection device and method. Background The cycle life, safety, rate capability and other core properties of the secondary battery are closely related to the structural stability of the electrode material in the cycle process and the evolution process of the electrode-electrolyte interface, wherein the electrode-electrolyte interface comprises a positive electrode-electrolyte interface CEI and a solid electrolyte interface film SEI. Therefore, deep analysis of the complex and dynamic reaction process of the electrode-electrolyte interface is a key technical support for developing the next generation of high-performance secondary batteries. At present, an ex-situ offline test method is mostly adopted for the characterization means of the secondary battery electrode material, the method needs to disassemble the battery after the battery finishes the specified cycle times, and then subsequent detection analysis is carried out on the disassembled electrode material. The method can not capture intermediate state information in the electrode-electrolyte interface reaction process, and the battery disassembly process is easy to change or even destroy the original interface state, so that the final detection analysis result is deviated from the actual situation. In recent years, in-situ spectrum characterization technology is widely applied in the field of secondary battery detection, and in-situ Raman and in-situ X-ray diffraction are typical technologies. The Fourier transform infrared spectrum technology has unique technical advantages in the aspect of detecting molecular bond vibration information of polar functional groups and organic and inorganic components, and can be effectively applied to research on decomposition processes of organic electrolyte and electrolyte anions, and analysis of formation and evolution mechanisms of key components such as lithium oxide, lithium fluoride, various organic matters and the like in SEI and CEI films. However, the existing secondary battery in-situ detection technology based on Fourier transform infrared spectroscopy still has a plurality of technical problems to be solved, and the problems are that firstly, the spatial resolution is insufficient, the conventional transmission mode and the attenuated total reflection mode are difficult to realize accurate positioning and targeted analysis on specific micro areas such as single active particles and cracks on the surface of an electrode, secondly, strong bulk electrolyte signal interference exists, a large amount of bulk electrolyte has strong absorption effect on infrared light and seriously interferes with effective acquisition of weak signals of an electrode-electrolyte interface, thirdly, the compatibility of an in-situ battery and a detection instrument is poor, and the existing majority of simple in-situ batteries cannot realize good matching with a light path and a sample stage of the Fourier transform micro infrared spectrometer, and meanwhile, stable and reliable sealing performance and electric contact performance are difficult to maintain in a long-period electrochemical test process. In addition, in practical application, the battery is often required to be tightly fixed during alignment, deviation is avoided during alignment, when the lens of the Fourier transform micro infrared spectrometer is aligned with the battery, the battery is required to have a certain flexible adjustment space after the test can be started, so that the battery is convenient to meet the requirement of practical test, and the prior art is often suitable for the actual test, either only the fixation can be carried out or the fixation is completely abandoned, and the practical operation applicability is poor. In summary, the present invention provides an in-situ detection device and method for secondary batteries to solve the above-mentioned problems. Disclosure of Invention The invention provides a secondary battery in-situ detection device and method, which realize strict time sequence synchronization of spectrum acquisition and electrochemical data through a synchronous signal control system, and are matched with a micro-region accurate positioning function of a precise three-dimensional mobile platform and an optimized structural design of an in-situ battery so as to solve the problems that in the prior art, the spectrum acquisition and the electrochemical data lack of strict time sequence synchronization, the micro-region positioning precision is insufficient, the dynamic process monitoring is lagged, and the interface reaction space non-uniformity is difficult to characterize. The secondary battery in-situ detection device comprises an in-situ battery, wherein a precise three-dimensional moving platform is arranged below the in-situ battery, a