Lithium ion battery ultrasonic coupling medium

Abstract

The application discloses a kind of lithium ion battery ultrasonic coupling medium, comprising: epoxy resin, nano silicon oxide particles, cerium oxide, lanthanum oxide, agar and glycerol;Wherein: epoxy resin mass ratio is 10%~60%, nano silicon oxide particles mass ratio is 15%~30%, nano cerium oxide particle mass ratio is 2%~3%, nano lanthanum oxide particle mass ratio is 3%~4.5%, agar mass ratio is 0.4%~1.5%, glycerol is supplementary solvent.The application can improve interface affinity effect by inorganic filler to control medium hardness, can improve the wetting degree of lithium ion battery and ultrasonic detection device, improve the efficiency of sound wave transmission;The lithium ion battery ultrasonic coupling medium of the application has the advantages of close acoustic impedance with lithium battery, large density, adjustable hardness, not easy to volatilize, etc., which is beneficial to obtain high signal-to-noise ratio transmission ultrasonic signal.In addition, the coupling agent preparation method is simple, not easy to volatilize, and has large-scale application prospect.

Description

Technical Field

[0001] This invention belongs to the field of new energy technology, specifically relating to an ultrasonic coupling medium for lithium-ion batteries. Background Technology

[0002] Lithium-ion batteries, as a typical electrochemical energy storage device, have advantages such as high energy density, good conversion efficiency, flexible installation, and fast response rate, and are now widely used in grid energy storage and new energy vehicles.

[0003] Ultrasonic testing technology, a traditional detection technique widely used in biomedicine, industrial flaw detection, and other fields, features strong penetration, non-destructive properties, high sensitivity, and good directivity. Among various non-destructive characterization methods for batteries, ultrasonic scanning imaging technology offers advantages such as high sensitivity, low cost, and no impact on charging and discharging. It has promising application potential in identifying characteristics such as electrolyte wetting, gas generation, and lithium plating within batteries, as well as predicting the state of charge (SoC) and state of health (SoH) within the battery, and has been widely developed and researched in the battery field.

[0004] Since the ultrasonic transducer and the battery's metal surface are not wetted, a coupling material is needed as a sound transmission medium to improve ultrasonic transmission efficiency. However, traditional ultrasonic coupling media (water, glycerol, gel, etc.) are acoustically impedance mismatched with lithium-ion batteries, causing strong reflection of sound waves at the interface between the ultrasonic coupling medium and the battery. This reduces the intensity of the transmitted signal, leading to signal distortion and significantly increasing the difficulty of signal processing and analysis. Furthermore, the solvent in traditional gel-based coupling agents is volatile, and the resulting voids further block the propagation of sound waves. Commonly used focused ultrasonic transducers are prone to cavitation of the coupling agent, accelerating medium evaporation and causing severe sound wave attenuation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an ultrasonic coupling medium for lithium-ion batteries to improve the wetting degree between lithium-ion batteries and ultrasonic detection devices and improve the sound wave transmission efficiency.

[0006] To address the aforementioned technical problems, this invention provides an ultrasonic coupling medium for lithium-ion batteries, comprising: epoxy resin, nano-silica particles, nano-cerium oxide particles, nano-lanthanum oxide particles, agar, and glycerol; wherein: the epoxy resin accounts for 10%~60% by mass, the nano-silica particles account for 15%~30% by mass, the nano-cerium oxide particles account for 2%~3% by mass, the nano-lanthanum oxide particles account for 3%~4.5% by mass, the agar accounts for 0.4%~1.5% by mass, and glycerol is used as a supplementary solvent.

[0007] Furthermore, the epoxy resin is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and polyphenol type glycidyl ether epoxy resin.

[0008] Furthermore, the nano-silica particles have a particle size of less than 50 nm and a specific surface area of ​​greater than 120 m². 2 / g.

[0009] Furthermore, the density of the ultrasonic coupling medium for the lithium-ion battery is greater than 1.5 g / cm³. 3 .

[0010] Furthermore, the mass percentages of each component in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin accounts for 60% of the mass; nano-silica particles account for 30% of the mass; nano-cerium oxide particles account for 3% of the mass; nano-lanthanum oxide particles account for 4.5% of the mass; agar accounts for 1.5% of the mass; and the supplementary solvent glycerol accounts for 1% of the mass.

[0011] Furthermore, the mass percentages of each component in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin accounts for 45% of the mass; nano-silica particles account for 25% of the mass; nano-cerium oxide particles account for 2.8% of the mass; nano-lanthanum oxide particles account for 4% of the mass; agar accounts for 1% of the mass; and the supplementary solvent glycerol accounts for 22.2% of the mass.

[0012] Furthermore, the mass percentages of each component in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin accounts for 25% of the mass; nano-silica particles account for 20% of the mass; nano-cerium oxide particles account for 2.4% of the mass; nano-lanthanum oxide particles account for 3.5% of the mass; agar accounts for 0.8% of the mass; and the supplementary solvent glycerol accounts for 48.3% of the mass.

[0013] Furthermore, the mass percentages of each component in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin accounts for 10% of the mass; nano-silica particles account for 15% of the mass; nano-cerium oxide particles account for 2% of the mass; nano-lanthanum oxide particles account for 3% of the mass; agar accounts for 0.4% of the mass; and the supplementary solvent glycerol accounts for 69.6% of the mass.

[0014] The present invention offers the following advantages: By using inorganic fillers to regulate the hardness of the medium and improve interfacial affinity, the present invention can improve the wetting degree between lithium-ion batteries and ultrasonic detection devices, thereby increasing sound wave transmission efficiency. The ultrasonic coupling medium for lithium-ion batteries in this invention has advantages such as similar acoustic impedance to lithium batteries, high density, adjustable hardness, and low volatility, which is beneficial for obtaining high signal-to-noise ratio transmitted ultrasonic signals. Furthermore, the preparation method of this coupling agent is simple, it is not volatile, and it has promising prospects for large-scale application. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a test ultrasonic waveform of Embodiment 1 of the present invention.

[0017] Figure 2 This is a test ultrasonic waveform of Embodiment 2 of the present invention.

[0018] Figure 3 This is a test ultrasonic waveform of Embodiment 3 of the present invention.

[0019] Figure 4 This is a test ultrasonic waveform from Embodiment 4 of the present invention.

[0020] Figure 5 This is an ultrasonic waveform of the hydrogel medical coupling agent tested in an embodiment of the present invention. Detailed Implementation

[0021] The following description of the embodiments is taken with reference to the accompanying drawings, which illustrate specific embodiments in which the invention can be implemented.

[0022] The casing of lithium-ion batteries is generally made of aluminum or stainless steel, which typically has a high acoustic impedance. To address the interface coupling matching problem in lithium-ion batteries and achieve good sound wave transmission, this invention provides an ultrasonic coupling medium for lithium-ion batteries, comprising: epoxy resin, nano-silica particles, nano-cerium oxide particles, nano-lanthanum oxide particles, agar, and glycerol; wherein: the epoxy resin accounts for 10%~60% by mass, the nano-silica particles account for 15%~30% by mass, the nano-cerium oxide particles account for 2%~3% by mass, the nano-lanthanum oxide particles account for 3%~4.5% by mass, the agar accounts for 0.4%~1.5% by mass, and glycerol is used as a supplementary solvent.

[0023] As can be seen from the above, this invention improves interfacial affinity by regulating the hardness of the medium using inorganic fillers, which can improve the wetting degree between lithium-ion batteries and ultrasonic detection devices, increase sound wave transmission efficiency, and facilitate the acquisition of high signal-to-noise ratio transmission signals. Furthermore, the preparation method of this coupling agent is simple, non-volatile, and has promising prospects for large-scale application.

[0024] The ultrasonic coupling medium for lithium-ion batteries of the present invention will be further described in detail below with four embodiments.

[0025] Example 1:

[0026] The ultrasonic coupling medium for the lithium-ion battery in this embodiment has a total mass of 10 kg, and the mass percentages of its components are as follows:

[0027] The mixture consisted of 60% epoxy resin, 30% nano-silica particles, 3% nano-cerium oxide particles, 4.5% nano-lanthanum oxide particles, 1.5% agar, and 1% glycerol as a supplementary solvent. The prepared coupling medium was degassed and surface-treated before acoustic parameter testing. The ultrasonic waveform was measured as follows: Figure 1 As shown.

[0028] Example 2:

[0029] The ultrasonic coupling medium for the lithium-ion battery in this embodiment has a total mass of 10 kg, and the mass percentages of its components are as follows:

[0030] The mixture consisted of 45% epoxy resin, 25% nano-silica particles, 2.8% nano-cerium oxide particles, 4% nano-lanthanum oxide particles, 1% agar, and 22.2% glycerol as a supplementary solvent. The prepared coupling medium was degassed and surface-treated before acoustic parameter testing. The ultrasonic waveform was measured as follows: Figure 2 As shown.

[0031] Example 3:

[0032] The ultrasonic coupling medium for the lithium-ion battery in this embodiment has a total mass of 10 kg, and the mass percentages of its components are as follows:

[0033] The mixture consisted of 25% epoxy resin, 20% nano-silica particles, 2.4% nano-cerium oxide particles, 3.5% nano-lanthanum oxide particles, 0.8% agar, and 48.3% glycerol as a supplementary solvent. The prepared coupling medium was degassed and surface-treated before acoustic parameter testing. The ultrasonic waveform was measured as follows: Figure 3 As shown.

[0034] Example 4:

[0035] The ultrasonic coupling medium for the lithium-ion battery in this embodiment has a total mass of 10 kg, and the mass percentages of its components are as follows:

[0036] The mixture consisted of 10% epoxy resin, 15% nano-silica particles, 2% nano-cerium oxide particles, 3% nano-lanthanum oxide particles, 0.4% agar, and 69.6% glycerol as a supplementary solvent. The prepared coupling medium was degassed and surface-treated before acoustic parameter testing. The ultrasonic waveform was measured as follows: Figure 4 As shown.

[0037] At 25℃, a 30mm thick liquid-filled square hard-shell lithium-ion battery was used as the test object. Tests were conducted using the above-mentioned coupling media, with a certain hydrogel medical coupling medium as a reference. The center frequency of the ultrasonic transducer was 2MHz. Ultrasonic waves transmitted through the battery in different media were collected. Figure 5 As shown in the table below:

[0038]

[0039] The measured parameters of sound velocity, acoustic characteristic impedance, and acoustic attenuation coefficient slope indicate that the ultrasonic coupling medium for lithium-ion batteries in Examples 1, 2, 3, and 4 has advantages such as high sound velocity and low acoustic attenuation coefficient slope. Its transmitted ultrasonic intensity is significantly higher than that of conventional medical ultrasonic coupling media, and it can achieve good acoustic compatibility with lithium-ion batteries.

[0040] Preferably, the epoxy resin is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and polyphenol type glycidyl ether epoxy resin. The nano-silica particles have a particle size not exceeding 50 nm and a specific surface area greater than 120 m². 2 / g. Cerium oxide has a high density, a spherical microstructure, and good dispersibility, allowing it to be uniformly distributed in the matrix medium without agglomeration, resulting in a medium with good consistency. Lanthanum oxide can accelerate the solidification of the medium, and the resulting coupling medium is not easily volatile.

[0041] The density of the ultrasonic coupling medium for the lithium-ion battery of this invention is greater than 1.5 g / cm³. 3 The lithium-ion battery is a square, hard-cased lithium-ion battery.

[0042] In this embodiment of the invention, the hardness of the coupling medium can be controlled by adjusting the ratio of nano-silica to lanthanum oxide. For example, increasing the content of nano-silica can improve the hardness of the coupling medium, or increasing the content of lanthanum oxide can improve the curing rate of the medium. Under conditions of 25~35℃, the sound wave emitted by the 2MHz focused ultrasonic probe propagates at a speed of 1700m / s~1950m / s in this coupling medium, with an acoustic impedance of 2.2 Mrayl~5.0 Mrayl and an acoustic attenuation coefficient of 0.05~1.0 dB / cm·MHz.

[0043] As can be seen from the above description, compared with the prior art, the beneficial effects of the present invention are as follows: The present invention improves the interfacial affinity by regulating the hardness of the medium through inorganic fillers, which can improve the wetting degree between lithium-ion batteries and ultrasonic detection devices and increase the sound wave transmission efficiency; the ultrasonic coupling medium for lithium-ion batteries of the present invention has advantages such as close acoustic impedance to that of lithium batteries, high density, adjustable hardness, and low volatility, which is conducive to obtaining high signal-to-noise ratio transmitted ultrasonic signals. In addition, the preparation method of this coupling agent is simple, it is not volatile, and has the prospect of large-scale application.

[0044] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An ultrasonic coupling medium for lithium-ion batteries, characterized in that, include: Epoxy resin, nano-silica particles, nano-cerium oxide particles, nano-lanthanum oxide particles, agar, and glycerol; wherein: epoxy resin The mass percentage of the nano-silica particles is 10%~60%, the mass percentage of the nano-silica particles is 15%~30%, the mass percentage of the nano-cerium oxide particles is 2%~3%, the mass percentage of the nano-lanthanum oxide particles is 3%~4.5%, the mass percentage of the agar is 0.4%~1.5%, and glycerol is used as a supplementary solvent.

2. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The epoxy resin is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and polyphenol type glycidyl ether epoxy resin.

3. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The nano-silica particles have a particle size of less than 50 nm and a specific surface area of ​​greater than 120 m². 2 / g.

4. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The density of the ultrasonic coupling medium for the lithium-ion battery is greater than 1.5 g / cm³. 3 .

5. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The mass percentages of the components in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin accounts for 60% of the mass; nano-silica particles account for 30% of the mass; nano-cerium oxide particles account for 3% of the mass; nano-lanthanum oxide particles account for 4.5% of the mass; agar accounts for 1.5% of the mass; and glycerol, the supplementary solvent, accounts for 1% of the mass.

6. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The mass percentages of the components in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin 45%; nano-silica particles 25%; nano-cerium oxide particles 2.8%; nano-lanthanum oxide particles 4%; agar 1%; and glycerol 22.2% as a supplementary solvent.

7. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, characterized in that, The mass percentages of the components in the ultrasonic coupling medium for the lithium-ion battery are as follows: epoxy resin 25%; nano-silica particles 20%; nano-cerium oxide particles 2.4%; nano-lanthanum oxide particles 3.5%; agar 0.8%; and glycerol as a supplementary solvent 48.3%.

8. The ultrasonic coupling medium for lithium-ion batteries according to claim 1, wherein the mass percentages of each component of the ultrasonic coupling medium for lithium-ion batteries are as follows: epoxy resin 10%; nano-silica particles 15%; nano-cerium oxide particles 2%; nano-lanthanum oxide particles 3%; agar 0.4%; and glycerol as a supplementary solvent 69.6%.

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