Device for improving charging efficiency of lithium ion battery based on surface acoustic wave

Abstract

The invention discloses a device for improving the charging efficiency of a lithium ion battery based on surface acoustic waves. The acoustic surface wave sensor belongs to the technical field of intersection of acoustics and electrochemistry and comprises a signal generator, a power amplifier, an acoustic surface wave sensor and a lithium ion battery, the signal generator is connected with the power amplifier, the power amplifier is connected to the surface acoustic wave sensor, and a signal of the surface acoustic wave sensor is connected to the lithium battery through epoxy resin; a computer is used for controlling a signal generator to output an electric signal, a power amplifier amplifies the power of a received signal and outputs the power to a surface acoustic wave sensor, an input transducer on the sensor converts the input electric signal into an acoustic signal through an inverse piezoelectric effect, the acoustic signal is finally converted into an electric signal and output to a lithium battery, and an electrolyte is driven to flow; the surface acoustic wave sensor of the device can concentrate signals on the surface of the substrate, the working frequency is high, detected information can be quickly converted into electric signals to be output, and the device has the advantages of miniaturization, integration, direct frequency signal output and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of the intersection of acoustics and electrochemistry, and relates to a device for improving the charging efficiency of a lithium-ion battery based on surface acoustic waves. Background Art

[0002] Lithium-ion batteries are a type of battery that is widely used in modern times. They are widely used in defense electronics, grid energy storage, robotics, and electric vehicles for sustainable transportation. Compared with traditional batteries, lithium-ion batteries have the advantages of being more energy-efficient and environmentally friendly, lightweight, and having a longer cycle life. However, lithium-ion also faces some challenges in its development. The first and foremost is the unstable charging efficiency. During the charging process, there is a serious ion depletion gradient in the electrolyte, which will quickly form porosity, dendrites, and dead lithium, resulting in poor performance and low energy density. The energy density of the best lithium-ion batteries currently is only 6 times that of lead-acid batteries 120 years ago. These problems have long hindered the commercialization of lithium metal batteries, despite their overwhelming advantages in other aspects.

[0003] At present, there are some solutions to the problem of low charging efficiency of lithium-ion batteries. A Chinese patent (patent number: CN115692692A) provides a method for preparing a negative electrode active material for a lithium-ion battery, wherein the negative electrode active material is prepared by etching graphite with an organic phosphonic acid, wherein the structural formula of the organic phosphonic acid is: The negative electrode active material etches graphite with an organic phosphonic acid to produce pores or holes on the surface of the graphite, thereby increasing the deintercalation sites of lithium ions, reducing the diffusion distance of lithium ions during the charge and discharge process, and reducing the polarization of the lithium-ion battery, thereby improving the charging efficiency of the lithium-ion battery. However, this method cannot increase the diffusion rate of ions in the electrolyte, and the implementation process is relatively complicated, and it cannot be widely used.

[0004] Therefore, it is necessary to improve the existing technology to solve the shortcomings of the existing technology. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves.

[0006] Technical solution: The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves described in the present invention includes a lithium-ion battery and a surface acoustic wave sensor for improving the battery charging efficiency, and a power amplifier and a signal generator are connected to the surface acoustic wave sensor.

[0007] Furthermore, the surface acoustic wave sensor includes a piezoelectric substrate, on which two groups of signal receiving ends, a sound absorbing material, an input interdigital transducer and an output interdigital transducer are respectively mounted.

[0008] Furthermore, the lithium-ion battery includes a battery housing, on which a battery anode, a separator, a battery cathode, an electrolyte, a positive electrode tab, and a negative electrode tab are installed.

[0009] Furthermore, the piezoelectric substrate of the surface acoustic wave sensor is connected to the battery shell of the lithium-ion battery through epoxy resin.

[0010] Furthermore, a small hole is opened on the battery shell at the connection between the surface acoustic wave sensor and the lithium-ion battery.

[0011] Furthermore, the signal generator is connected to a power amplifier via a wire, and the power amplifier is connected to a signal receiving end of the surface acoustic wave sensor via a wire.

[0012] Furthermore, the signal generator is a sinusoidal signal generator, and its frequency is usually 200KHz to 30MHz.

[0013] Furthermore, the power amplifier is an integrated circuit amplifier.

[0014] Furthermore, the shape of the battery housing includes but is not limited to a cuboid, a cylinder, and a hexagonal prism; and its material includes but is not limited to aluminum alloy and stainless steel;

[0015] The material used for the battery anode is lithium manganese oxide, lithium cobalt oxide or nickel cobalt lithium manganese oxide;

[0016] The isolation membrane is a polymer film with a microporous structure;

[0017] The material used for the battery cathode is graphite or carbon;

[0018] The electrolyte includes but is not limited to ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate;

[0019] The material used for the positive electrode ear is aluminum;

[0020] The material used for the negative electrode ear is nickel or copper-nickel-plated material.

[0021] Furthermore, the materials used for the piezoelectric substrate include but are not limited to ceramics, crystals and polymers;

[0022] The sound absorbing material is made of hard fiber, asbestos cement or gypsum;

[0023] The input IDT and the output IDT are made of silver-plated copper or stainless steel.

[0024] Beneficial effects: Compared with the existing technology, the present invention has the following significant characteristics: 1. Simple structure, low cost, good stability, low difficulty in use, and conducive to wide application; 2. Surface acoustic wave devices can achieve highly selective frequency filtering, effectively suppress unnecessary signals, and improve signal clarity and quality; 3. The application of surface acoustic waves to the miniaturization development of lithium-ion batteries can provide possibilities for it, help promote its practical application, and provide a theoretical basis for its commercialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a schematic structural diagram of the lithium-ion battery of the present invention;

[0027] Figure 3 Schematic diagram of the structure of the surface acoustic wave sensor of the present invention;

[0028] In the figure, 1-signal generator, 2-power amplifier, 3-lithium-ion battery, 301-battery housing, 302-battery anode, 303-isolation membrane, 304-battery cathode, 305-electrolyte, 306-positive ear, 307-negative ear, 4-surface acoustic wave sensor, 401-piezoelectric substrate, 402-signal receiving end, 403-sound absorbing material, 404-input interdigital transducer, 405-output interdigital transducer, 5-wire. DETAILED DESCRIPTION

[0029] The specific technical solutions of the present invention are further described in detail below with reference to specific examples.

[0030] As shown in the figure, the device for improving the charging efficiency of a lithium-ion battery based on surface acoustic waves according to the present invention includes a signal generator 1, a power amplifier 2, a lithium-ion battery 3, a surface acoustic wave sensor 4, and a wire 5;

[0031] The signal generator 1 is connected to the power amplifier 2, and the other side of the power amplifier 2 is connected to the signal receiving end 402 of the surface acoustic wave sensor 4, and the two are connected via a wire 5;

[0032] The piezoelectric substrate 401 of the surface acoustic wave sensor 4 is connected to the battery casing 301 of the lithium battery 3 through epoxy resin, and a small hole is opened on the battery casing 301 at the connection point; the signal generator 1 is controlled by a computer to output an electrical signal, and the power amplifier 2 amplifies the power of the received signal and outputs it to the surface acoustic wave sensor 4. The input interdigital transducer 404 on the sensor converts the input electrical signal into an acoustic signal through the inverse piezoelectric effect. This acoustic signal propagates along the surface of the piezoelectric substrate 401, and is finally converted into an electrical signal by the output interdigital transducer 405 and output to the lithium battery 3, driving the electrolyte 305 to flow, increasing the particle diffusion rate, allowing it to pass through the gap between the electrodes, preventing the formation of a lithium ion depletion zone, thereby preventing dendrites, adverse heating and electrolyte rupture, and improving its charging performance; the surface acoustic wave sensor 4 used in this device can concentrate the signal on the substrate surface, has a high operating frequency, has extremely high information sensitivity accuracy, can quickly convert the detected information into an electrical signal output, and also has the advantages of miniaturization, integration, low cost, low power consumption, and direct frequency signal output.

[0033] The signal generator 1 is a sine wave signal generator, and its frequency is usually 200KHz-30MHz.

[0034] The power amplifier 2 is connected to the signal generator 1 and is used to receive and amplify the received signal. The power amplifier 2 is an integrated circuit amplifier, which is usually used in low-power, small-size applications and can provide good performance and stability.

[0035] The lithium-ion battery 3 includes a battery housing 301 , a battery anode 302 , a separator 303 , a battery cathode 304 , an electrolyte 305 , a positive electrode tab 306 , and a negative electrode tab 307 .

[0036] The surface acoustic wave sensor 4 includes a piezoelectric substrate 401 , a signal receiving end 402 , a sound absorbing material 403 , an input interdigital transducer 404 , and an output interdigital transducer 405 .

[0037] The shape of the battery housing 301 includes but is not limited to a cuboid, a cylinder, and a hexagonal prism; and the material thereof includes but is not limited to aluminum alloy, stainless steel, and the like.

[0038] The positive electrode tab 306 is usually made of aluminum, and the negative electrode tab 307 is usually made of nickel or copper-nickel-doped material.

[0039] The material of the battery anode 302 is usually lithium manganese oxide, lithium cobalt oxide or lithium nickel cobalt manganese oxide;

[0040] The material of the battery cathode 304 is usually graphite, or carbon with a structure similar to graphite;

[0041] The isolation membrane 303 is usually made of a specially formed polymer film with a microporous structure;

[0042] The types of the electrolyte 305 include but are not limited to ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, etc.

[0043] The material of the piezoelectric substrate 401 includes but is not limited to ceramics, crystals and polymers;

[0044] The materials of the input IDT 404 and the output IDT 405 are usually silver-plated copper or stainless steel;

[0045] The sound absorbing material 403 is usually hard fiber, asbestos cement or gypsum.

[0046] This experiment first requires the preparation of lithium-ion batteries 3. 10 μm thick copper is immersed in 1M hydrochloric acid, first rinsed with water, then with acetone to remove surface impurities and oxides, and then used as electrodes for all experiments;

[0047] In this experiment, Li (250 μm thick) was carefully scraped (245 μm thick after scraping) to remove any oxide layer before use as an electrode;

[0048] Lithium iron phosphate electrode First, LFP powder, polyvinylidene fluoride and carbon black are mixed into LFP:PVDF:C=75%:10%:15%;

[0049] Then mix with N-methyl-2-pyrrolidone as solvent to make a slurry; pour it on aluminum foil;

[0050] Finally, dry in a vacuum oven for 12 hours. The area capacity is about 1 mAh / cm 2 ;

[0051] A 1 M grade lithium hexafluorophosphate solution in a 1:1 mixture of ethylene carbonate and diethyl carbonate was used as the electrolyte 305;

[0052] Finally, a Celgard 480 separator was used between the cell cathode 304 and the cell anode 302;

[0053] The surface acoustic wave sensor 4 was fabricated by emission lithography, depositing a pair of unweighted Au / Cr interdigital transducers and placing them on a 500 μm thick 127.68 ° The optimal interdigital sensor is formed on the lithium niobate substrate by y-rotation and x-propagation cutting;

[0054] After washing with dimethyl carbonate to remove the residual electrolyte, the electrodes were fixed in the battery housing 301 using double-sided carbon tape;

[0055] After transferring the sample to the SEM, the sample was quickly transferred from the bag to the SEM, and the electrode material was imaged at 10 kV and the separator was imaged at 5 kV;

[0056] The samples were exposed to air for less than three seconds to avoid air contamination;

[0057] After the lithium battery 3 and the surface acoustic wave sensor 4 are prepared, the signal output end of the surface acoustic wave sensor 4 is bonded to the battery housing 301 of the lithium battery 3 using epoxy resin, and a small hole is provided on the lithium battery housing 301 at the connection point;

[0058] Another group, without the SAW sensor 4, served as a control experiment, observing the results and ultimately drawing conclusions. The SAW sensor used in this device can concentrate the signal on the substrate surface, operates at a high frequency, and quickly converts the detected information into an electrical signal output. It also offers advantages such as miniaturization, integration, and direct frequency signal output.

Claims

1. A device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves, characterized by: The invention comprises a lithium ion battery (3) and a surface acoustic wave sensor (4) for improving the battery charging efficiency. A power amplifier (2) and a signal generator (1) are connected to the surface acoustic wave sensor (4).

2. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 1, characterized in that: The surface acoustic wave sensor (4) comprises a piezoelectric substrate (401), on which two groups of signal receiving ends (402), a sound absorbing material (403), an input interdigital transducer (404) and an output interdigital transducer (405) are respectively arranged.

3. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 2, characterized in that: The lithium-ion battery (3) comprises a battery housing (301), on which a battery anode (302), a separator (303), a battery cathode (304), an electrolyte (305), a positive electrode tab (306) and a negative electrode tab (307) are mounted.

4. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 3, characterized in that: The piezoelectric substrate (401) of the surface acoustic wave sensor (4) is connected to the battery housing (301) of the lithium-ion battery (3) through epoxy resin.

5. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 4, characterized in that: A hole is provided on the battery housing (301) at the connection between the surface acoustic wave sensor (4) and the lithium-ion battery (3).

6. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 1, characterized in that: The signal generator (1) is connected to the power amplifier (2) via a wire (5), and the power amplifier (2) is connected to the signal receiving end (402) of the surface acoustic wave sensor (4) via the wire (5).

7. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 6, characterized in that: The signal generator (1) is a sine signal generator, and its frequency is usually 200KHz to 30MHz.

8. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 6, characterized in that: The power amplifier (2) is an integrated circuit amplifier.

9. The device for improving the charging efficiency of lithium-ion batteries based on surface acoustic waves according to claim 3, characterized in that: The shape of the battery housing (301) includes but is not limited to a cuboid, a cylinder, and a hexagonal prism; and its material includes but is not limited to aluminum alloy and stainless steel; The battery anode (302) is made of lithium manganese oxide, lithium cobalt oxide or nickel cobalt lithium manganese oxide. The isolation membrane (303) is a polymer film having a microporous structure; The material used for the battery cathode (304) is graphite or carbon; The electrolyte (305) includes but is not limited to ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate; The material used for the positive electrode ear (306) is aluminum; The material used for the negative electrode ear (307) is nickel or copper-nickel-plated material.

10. The method for improving the charging efficiency of a lithium-ion battery based on surface acoustic waves according to claim 2, characterized in that: The materials used for the piezoelectric substrate (401) include but are not limited to ceramics, crystals and polymers; The sound absorbing material (403) is made of hard fiber, asbestos cement or gypsum; The input interdigital transducer (404) and the output interdigital transducer (405) are made of silver-plated copper or stainless steel.

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