A method for using Bessel laser punched electrodes in high-performance batteries
By spraying ion-conductive and electron-non-conductive slurry on the electrode surface and using Bessel laser to create a pore structure, the problem of Bessel laser sidelobe damage was solved, the electrode processing of high-performance batteries was achieved, and the power density and rate performance of the battery were improved.
Patent Information
- Application Number
- CN202411582936.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2044-11-07
AI Technical Summary
When Bessel laser processes materials with good electronic conductivity, sidelobe damage causes additional electrode loss, affecting the capacity and rate performance of the battery. Existing methods are not compatible with the battery preparation process.
Ion-conducting and electron-non-conducting slurry is sprayed on the electrode surface, and the pore structure is manufactured by Bessel laser focusing to suppress side lobe damage. The pores are manufactured using an ultrasonic sprayer and a Bessel laser processing system.
Reduce electrode loss, improve battery power density and rate performance, the pore structure promotes lithium ion migration, reduces internal resistance, and improves battery performance.
Smart Images
Figure CN119627030B_ABST
Abstract
Description
[0001] The invention discloses a method for using a Bessel laser to punch an electrode for a high-performance battery, which belongs to the field of electrode laser processing technology. Background Art
[0002] Bessel beams have the advantages of an extremely small central spot diameter, no diffraction, and a long focal depth, making them more suitable for processing structures with high aspect ratios. However, Bessel lasers can cause a large proportion of sidelobe damage to the material during processing, with the intensity of the first-order sidelobe being approximately 16% of that of the central beam. In practical applications, Bessel lasers are often used to process materials with poor electronic conductivity, such as glass and polymers. Because these materials have relatively weak absorption of femtosecond lasers, the loss caused by Bessel sidelobes is almost non-existent and the advantages of a high aspect ratio can be fully utilized. When Bessel beams process materials with strong absorption, such as electrodes, metals, and other materials with good electronic conductivity, these sidelobes will cause unnecessary losses to the sample.
[0003] In the actual processing of electrodes, machining through-holes with a high aspect ratio and low loss can help improve the rate performance of the electrodes. Traditional methods of manufacturing pore structures, such as calendering, are incompatible with battery processes. The advantage of the long focal depth of Bessel lasers is conducive to the processing of through-holes, and the small spot diameter can meet the advantage of low loss. It is a very advantageous electrode through-hole processing tool and is compatible with existing battery preparation methods. However, in actual through-hole processing, the loss caused by the Bessel side lobes will lead to additional loss of the electrode. Therefore, for Bessel laser processing electrodes, a method is needed that can suppress sidelobe damage without affecting the properties of the electrode itself, which will ultimately be used to improve the capacity and rate performance of the battery. Summary of the Invention
[0004] In order to meet and solve the problem of unnecessary damage to the material caused by side lobes when Bessel processing high-absorption electrodes in the existing method and the battery's demand for high power density, the present invention adopts an ultrasonic sprayer to spray ion-conductive and electronically non-conductive slurry on the electrode surface, and uses Bessel laser to focus on the electrode surface to manufacture the pore structure, thereby suppressing the side lobe damage during Bessel laser electrode pore manufacturing, reducing unnecessary electrode loss, and improving the power density of the battery.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is:
[0006] The present invention discloses a method for using Bessel laser punched electrodes in high-performance batteries. The method adopts an ultrasonic sprayer to spray an ion-conductive and electron-non-conductive slurry on the electrode surface, and focuses a Bessel laser on the electrode surface to manufacture a pore structure. The method suppresses sidelobe damage during Bessel laser electrode pore manufacturing, reduces unnecessary electrode loss, and improves the power density of the battery.
[0007] Furthermore, the ion-conductive and electronically non-conductive slurry is mainly obtained by ultrasonically mixing a solid electrolyte, a binder and a solvent, and the added amounts are 500 mg of solid electrolyte, 5% by mass of the binder and 5 mL of the solvent, respectively.
[0008] Furthermore, the solid electrolyte is LLZTO, LATP or LAGP; the binder is PVDF, PEO or PAN; and the solvent is ethanol or acetone.
[0009] A method for using Bessel laser-drilled electrodes in high-performance batteries, comprising the following steps:
[0010] Step 1: Prepare an ion conductive electronic non-conductive slurry, dissolve the solid electrolyte and binder in a solvent by ultrasonic rotation to prepare a uniformly mixed ion conductive electronic non-conductive slurry;
[0011] Step 2: Using an ultrasonic sprayer, the pre-prepared ion conductive and electronically non-conductive slurry is atomized into fine particles by an ultrasonic atomization device, and then evenly coated on the electrode surface by a carrier gas, thereby forming an ion conductive and electronically non-conductive slurry coating of a predetermined thickness on the electrode surface;
[0012] Step 3: Build a Bessel laser processing system using a Bessel cutting head and an illumination system, place the electrode coated with an ion-conductive and electronically non-conductive slurry on a mobile platform, and set a program to perform impact drilling to prepare a pore array;
[0013] Step 4: The electrodes with pore structures prepared by this method and the untreated electrodes are assembled into batteries respectively. The performance of the batteries is tested and compared using a blue-electric tester. The results show that the electrodes processed with pore arrays exhibit better rate performance.
[0014] Furthermore, the Bessel laser processing system includes: a femtosecond laser, an aperture, an ultrafast laser reflection group, a mechanical switch, a computer, a dichroic mirror, a Bessel cutting head, an electrode, a three-dimensional precision translation stage, a beam splitter, white light, and a CCD dynamic imaging unit; the femtosecond laser emitted by the femtosecond laser is collimated by the aperture, then passes through the reflection mirror group and the mechanical switch, is reflected by the dichroic mirror into the Bessel cutting head and focused onto the electrode sample located on the precision translation stage; the white light source passes through the beam splitter, the dichroic mirror, and the CCD dynamic imaging unit to jointly realize real-time imaging and monitoring of Bessel laser drilling on the electrode surface; the mechanical switch and the CCD dynamic imaging unit are connected to the computer to realize linkage control.
[0015] Furthermore, the Bessel cutting head can convert Gaussian laser into Bessel laser and can withstand relatively high laser energy. It uses a 2° conical lens, a 100 mm plano-convex lens, and a 20x objective lens. Beneficial effects
[0016] 1. This invention discloses a method for drilling electrodes for high-performance batteries using Bessel lasers. The method utilizes a Bessel laser processing system comprising a femtosecond laser, an aperture, an ultrafast laser reflector assembly, a mechanical switch, a dichroic mirror, a Bessel cutting head, a three-dimensional precision translation stage, electrodes, white light, a beam splitter, and a CCD dynamic imaging unit. The Bessel laser generated by this system has the advantages of an extremely small spot diameter, no diffraction, and a long focal depth. The long focal depth is advantageous for machining through holes, while the small spot diameter provides low loss and is compatible with existing battery manufacturing processes. Therefore, this Bessel laser processing system can be used to manufacture pore structures in electrodes.
[0017] 2. The present invention discloses a method for using a Bessel laser punched electrode in a high-performance battery, which uses an ultrasonic sprayer to spray an ion-conductive and electronically non-conductive slurry on the surface of the electrode. The high ionic conductivity enables the slurry to conduct lithium ions when applied to the battery, thereby maintaining the excellent performance of the battery; the low electronic conductivity enables it to be coated on the electrode as a protective layer to absorb the energy at the Bessel side lobe, suppress the side lobe damage of the electrode, and retain the electrode at the side lobe, thereby not affecting the capacity of the electrode.
[0018] 3. The present invention discloses a method for using Bessel laser punched electrodes in high-performance batteries. The electrodes with a porous structure prepared by the method and the untreated electrodes are assembled into batteries respectively. The introduction of the porous structure is beneficial to the penetration of the electrolyte and the migration of lithium ions, thereby reducing the internal resistance. The electrodes treated by the method exhibit higher capacity and rate performance, and improve the power density of the electrode, thereby making the method applicable to high-performance batteries. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 The figure is a flow chart of a method for using Bessel laser punched electrodes for high-performance batteries in the present invention.
[0020] Figure 2 The invention relates to a method for preparing an ion conductive and electronically non-conductive slurry.
[0021] Figure 3 The ultrasonic sprayer is used to spray ion conductive and electronic non-conductive slurry on the electrode.
[0022] Figure 4 Schematic diagram of the Bessel laser processing system.
[0023] Figure 5 The figure shows the morphology comparison results of Bessel laser drilling on the sprayed and unsprayed slurry electrodes.
[0024] Figure 6 is the light intensity distribution of Bessel laser at different positions.
[0025] Figure 7 A comparison chart of the rate performance of batteries assembled with Bessel laser-punched and non-punched electrodes.
[0026] Among them: 1—femtosecond laser, 2—aperture, 3—ultrafast laser reflection group, 4—mechanical switch, 5—computer, 6—dichroic mirror, 7—Bessel cutting head, 8—electrode, 9—three-dimensional precision translation stage, 10—beam splitter, 11—white light, 12—CCD dynamic imaging unit. DETAILED DESCRIPTION
[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited to the following embodiments.
[0028] like Figure 1 As shown, this embodiment discloses a method for using Bessel laser drilling electrodes for high-performance batteries. An ultrasonic sprayer is used to spray an ion-conductive and electronically non-conductive slurry on the electrode surface. A Bessel laser is focused on the electrode surface to create a pore structure. This suppresses sidelobe damage during Bessel laser electrode pore manufacturing, reduces unnecessary electrode loss, and improves the power density of the battery. This embodiment discloses a method for using Bessel laser drilling electrodes for high-performance batteries. The specific implementation steps are as follows:
[0029] Step 1: Dissolve 500 mg of LATP solid electrolyte and 5% binder by weight in 5 ml of ethanol solvent by ultrasonic rotation. Figure 2 As shown, a uniformly mixed ion conductive and electronically non-conductive slurry is finally prepared.
[0030] The solid electrolyte can be ceramic powders such as lithium lanthanum zirconium tantalum oxide (LLZTO), lithium aluminum titanium phosphate (LATP) or lithium aluminum germanium phosphate (LAGP), the binder can be polymers such as polyvinylidene fluoride (PVDF), polyethylene oxide (PEO) or polyacrylonitrile (PAN), and the solvent can be ethanol or acetone.
[0031] Step 2: Use ultrasonic spraying machine to spray the pre-prepared ion conductive electronic non-conductive slurry, such as Figure 3 As shown in the figure, it is atomized into fine particles by an ultrasonic atomization device, and then evenly coated on the surface of a 60 μm thick lithium iron phosphate (LFP) electrode by a carrier gas, thereby forming a LATP ion-conductive and electronically non-conductive slurry coating of a certain thickness (~5 μm) on the electrode surface.
[0032] The thickness of the ion-conducting and electronically non-conductive paste film needs to be determined based on the thickness of the electrode. Too thick will not be conducive to Bessel laser drilling, while too thin will not fully absorb the energy from the side lobes. The optimal thickness should meet the following requirements: the coating thickness can absorb 16% of the energy from the Bessel side lobes, and 84% of the energy from the center spot can drill a hole with the combined thickness of the ion-conducting and electronically non-conductive paste and the electrode.
[0033] Step 3: The Bessel laser processing system includes: a femtosecond laser 1, an aperture 2, an ultrafast laser reflection group 3, a mechanical switch 4, a computer 5, a dichroic mirror 6, a Bessel cutting head 7, an electrode 8, a three-dimensional precision translation stage 9, a beam splitter 10, white light 11, and a CCD dynamic imaging unit 12; the femtosecond laser emitted by the femtosecond laser 1 is collimated by the aperture 2, passes through the reflection mirror group 3 and the mechanical switch 4, is reflected by the dichroic mirror 6 into the Bessel cutting head 7 and is focused onto the electrode sample 8 located on the precision translation stage 9; the white light source 11 passes through the beam splitter 10, the dichroic mirror 6, and the CCD dynamic imaging unit 12 to jointly realize real-time imaging and monitoring of Bessel laser drilling on the electrode surface; wherein the mechanical switch and the CCD dynamic imaging unit are connected to the computer to realize linkage control.
[0034] The Bessel cutting head can convert Gaussian laser into Bessel laser and can withstand relatively high laser energy. It uses a 2° conical lens, a 100 mm plano-convex lens, and a 20x objective lens.
[0035] Step 4: Use Bessel laser to impact punch the electrode coated with LATP ion-conductive and electronically non-conductive slurry and the uncoated electrode, and characterize the surface morphology of the sample by light microscopy and scanning electron microscopy. Figure 5 As shown, the untreated electrode has concentric rings around the machined pores, a result of sidelobe damage during Bessel laser machining of highly absorptive electrodes. However, the pore structure on the electrode coated with LATP ionically conductive and electronically non-conductive slurry is significantly reduced, with the pore size being controlled to 5 μm. Bessel laser sidelobe damage to the electrode is suppressed, reducing excess electrode loss.
[0036] like Figure 6 As shown in the figure, the focal depth of the Bessel laser spot at the center is long and the energy is strong, which can drill the total thickness of the ion-conducting and electron-non-conducting paste and the electrode. The side lobes also have a certain amount of energy, accounting for about 16% of the total energy. This light field distribution makes a series of concentric rings around the electrode pores (such as Figure 5 c).
[0037] Step 5: Assemble the electrode with porous structure prepared by this method and the untreated electrode into batteries, and test the capacity of the battery at different current densities using a blue electric test system, such as Figure 7As shown. Due to the introduction of the pore structure in the electrode, the electrolyte can penetrate into the pores, which is more conducive to the migration of lithium ions and reduces the internal resistance of the battery. Therefore, the electrode with a pore structure shows better capacity and rate performance than the untreated electrode above 5C, that is, the power density of the battery is improved. Specifically, the LFP electrode treated with a 60 μm laser obtained 77, 49, 33, 26 and 22 mAh g at 6C, 7C, 8C, 9C and 10C, respectively. -1 The specific capacities of the untreated electrodes were only 33, 16, 8, 4, and 2 mAh g -1 capacity, and power density increased by ~60%.
[0038] The electrode material selected in the present invention is LFP electrode material, and this method can also be applied to pore manufacturing of other electrode materials.
[0039] The above specific description further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for using Bessel laser drilling electrodes for high-performance batteries, characterized in that: The steps include: Step 1: Prepare an ion conductive electronic non-conductive slurry, dissolve the solid electrolyte and binder in a solvent by ultrasonic rotation to prepare a uniformly mixed ion conductive electronic non-conductive slurry; Step 2: Using an ultrasonic sprayer, the pre-prepared ion conductive and electronically non-conductive slurry is atomized into fine particles by an ultrasonic atomization device, and then evenly coated on the electrode surface by a carrier gas, thereby forming an ion conductive and electronically non-conductive slurry coating of a predetermined thickness on the electrode surface; Step 3: Build a Bessel laser processing system using a Bessel cutting head and an illumination system, place the electrode coated with an ion-conductive and electronically non-conductive slurry on a mobile platform, and set a program to perform impact drilling to prepare a pore array; Step 4: Assemble the prepared electrodes with porous structure into a battery.
2. The method according to claim 1, wherein: The ion-conductive and electron-non-conductive slurry is prepared by mixing 500 mg of solid electrolyte, 5% by weight of a binder, and 5 mL of a solvent.
3. The method according to claim 2, wherein: The solid electrolyte is LLZTO, LATP or LAGP; the binder is PVDF, PEO or PAN; and the solvent is ethanol or acetone.
4. The method according to claim 1, wherein: The Bessel laser processing system includes a femtosecond laser, an aperture, an ultrafast laser reflection group, a mechanical switch, a computer, a dichroic mirror, a Bessel cutting head, an electrode, a three-dimensional precision translation stage, a beam splitter, white light, and a CCD dynamic imaging unit; the femtosecond laser emitted by the femtosecond laser is collimated by the aperture, then passes through the reflection mirror group and the mechanical switch, is reflected by the dichroic mirror into the Bessel cutting head and focused onto the electrode sample located on the precision translation stage; the white light source passes through the beam splitter, the dichroic mirror, and the CCD dynamic imaging unit to jointly realize real-time imaging and monitoring of Bessel laser drilling on the electrode surface; the mechanical switch and the CCD dynamic imaging unit are connected to the computer to realize linkage control.
5. The method according to claim 4, wherein: The Bessel cutting head can convert Gaussian laser into Bessel laser and can withstand relatively high laser energy. It uses a 2° conical lens, a 100 mm plano-convex lens, and a 20x objective lens.