Etching equipment and etching method for current collector perforated foil of solid-state battery

Abstract

The invention relates to etching equipment and an etching method for a solid-state battery current collector perforated foil. The equipment comprises a winding and unwinding transmission assembly; the porous rotary drum is of a hollow cylinder structure, a micropore array is arranged on the cylindrical surface of the porous rotary drum, and the rotating linear speed of the porous rotary drum is synchronous with the metal foil conveying linear speed; the high-pressure liquid injection stator is coaxially arranged in the inner cavity of the porous rotary drum in a suspension manner, and a liquid injection port is only formed in a fan-shaped area corresponding to a metal foil coating angle and is used for continuously supplying high-pressure magnetorheological etching liquid to the inner wall of the rotating porous rotary drum; and the external magnetic field generation module is used for driving the magnetic abrasive in the magnetorheological etching liquid to grind the etching hole wall when penetrating through the metal foil. Through the arrangement of the magnetic field generation module, the magnetic abrasive in the magnetorheological etching liquid dynamically grinds the etching hole wall when etching the metal foil, so that the etching efficiency can be improved, the perpendicularity and smoothness of the etching hole can be ensured, and the controllability of the hole during etching is improved.

Description

An etching apparatus and etching method for perforated foil for current collectors in solid-state batteries Technical Field

[0001] This application relates to the technical field of solid-state battery production, and in particular to an etching apparatus and etching method for a perforated foil for a solid-state battery current collector. Background Technology

[0002] With the urgent need for high energy density and high safety in new energy vehicles, all-solid-state batteries are considered the core technology direction for next-generation power batteries. Unlike traditional liquid batteries, solid-state batteries use solid electrolytes. Their main challenges lie in the high solid-solid interface contact resistance and the interface failure caused by the volume expansion of active materials (such as silicon-based anodes) during charging and discharging. To address these issues, the industry is gradually replacing traditional planar metal foils with three-dimensional porous current collectors (perforated foils). Perforated foils not only increase ion transport channels (double-sided connectivity) but also effectively release stress and accommodate more active materials.

[0003] Currently, the mainstream process for preparing perforated foils with micron-sized pores (<20μm) is chemical etching. Existing chemical etching equipment usually adopts a "horizontal transport + surface spraying" mode similar to PCB (printed circuit board) production. Its working principle is: the metal foil with photoresist or photosensitive dry film is horizontally transported by rollers, and the etching solution is sprayed onto the surface of the foil using nozzles arranged above and below.

[0004] However, when mass etching is performed on the current collectors that are extremely thin (<6μm) and have extremely small pore size (<20μm) required for solid-state batteries, the existing technology has revealed the following insurmountable physical defects: (1) In the process of dense perforation of extremely thin metal foil, the traditional static or low flow rate etching solution is difficult to overcome the surface tension and viscous resistance, resulting in some micropores not being etched through (blind holes) or poor pore size consistency, and the retention of etching waste liquid in the holes will hinder the continued reaction; (2) Due to the isotropic characteristics of traditional etching, severe "side etching" is caused, making it difficult to control the hole shape. In the end, the hole wall presents an obvious arc or bowl shape with poor verticality, which reduces the mechanical strength and effective material loading of the current collector.

[0005] Therefore, there is an urgent need to study an etching process that can solve the above problems in order to improve the processing quality of perforated foil. Summary of the Invention

[0006] To address the problem that residual etching solution severely affects the etching rate and makes hole shape control difficult during the etching of perforated foil, this application provides an etching apparatus and etching method for perforated foil used in solid-state battery current collectors.

[0007] The etching equipment and etching method for a perforated foil current collector of a solid-state battery provided in this application adopt the following technical solution: The etching equipment for a perforated foil current collector of a solid-state battery provided in the first aspect of this application adopts the following technical solution: An etching equipment for a perforated foil current collector of a solid-state battery includes: a winding and unwinding conveyor assembly for driving the metal foil to be etched to be continuously conveyed at a preset linear speed; a porous drum, which is a hollow cylindrical structure with a micro-pore array on its cylindrical surface, the linear speed of the rotating porous drum being synchronized with the linear speed of the metal foil conveying, so that the metal foil is relatively stationary and attached to the outer wall of the porous drum at a preset wrap angle; a high-pressure liquid injection stator, which is coaxially suspended in the cavity inside the porous drum, and has liquid injection ports only in the fan-shaped area corresponding to the wrap angle of the metal foil, for continuously supplying high-pressure magnetorheological etching liquid to the inner wall of the rotating porous drum; and an external magnetic field generating module for driving the magnetic abrasive in the magnetorheological etching liquid to grind the etching hole wall when penetrating the metal foil.

[0008] Furthermore, the porous drum comprises, from the inside out, the following sequentially arranged components: a rigid support frame with a highly permeable mesh structure; a microporous flow equalization sintered layer sintered on the surface of the rigid support frame, serving as a bearing surface for the metal foil, wherein the micropore diameter is less than 1 / 2 of the aperture to be etched, used to convert the macroscopic liquid flow from the high-pressure liquid injection stator into a micro-jet stream; the outer surface of the microporous flow equalization sintered layer is mirror polished and oleophobic to ensure close adhesion to the metal foil and prevent lateral leakage of the etching solution.

[0009] Furthermore, the take-up and unwinding transport assembly includes two sets of conductive rollers arranged on both sides of the porous drum. The two sets of conductive rollers are used to apply an adsorption current along the transport direction to the metal foil that is attached to the outer wall of the porous drum at a preset wrap angle. The external magnetic field generating module is also configured to generate an adsorption magnetic field parallel to the axis of the porous drum. The adsorption magnetic field and the adsorption current work together to generate a Lorentz force on the metal foil pointing towards the center of the porous drum, so that the metal foil is electromagnetically adsorbed onto the surface of the porous drum.

[0010] Furthermore, the minimum adsorption current applied to the metal foil by the conductive roller assembly satisfies: ;in, As a preset safety factor, and ; Let be the areal density of the metal foil. The rotational angular velocity of the porous drum is... The radius of the multi-hole drum, The effective width of the metal foil, The magnetic field strength of the adsorption magnetic field is given.

[0011] Furthermore, the external magnetic field generating module includes: a C-shaped magnetic yoke array, which covers the outer side of the etching area along the circumferential direction of the porous drum, with its two poles pointing to the two ends of the axis of the porous drum, for generating the adsorption magnetic field; and a high-frequency dynamic coil group, which is embedded in the magnetic pole surface of the C-shaped magnetic yoke array, for superimposing and generating an AC pulse magnetic field perpendicular to the surface of the metal foil. The AC pulse magnetic field is used to drive the magnetic abrasive in the magnetorheological etching solution to generate reciprocating oscillation and rotational motion, and to dynamically grind the etching hole wall.

[0012] Furthermore, a non-magnetic conductive mesh belt is provided between the external magnetic field generating module and the porous drum. The non-magnetic conductive mesh belt is configured to physically press the metal foil onto the outer surface of the porous drum in the etched area of ​​the metal foil, and to synchronously transport the metal foil and the porous drum at the same angular velocity.

[0013] Furthermore, a conductive rubber layer is provided on the side of the non-magnetic conductive mesh belt that contacts the metal foil.

[0014] Furthermore, a transmittance detector is provided downstream of the winding and unwinding conveyor assembly, and the transmittance detector is connected to an inspection controller; the inspection controller is configured to control the high-pressure liquid injection stator to increase the liquid supply pressure and / or control the winding and unwinding conveyor assembly and the multi-hole drum to synchronously reduce the conveying speed when the transmittance detected by the transmittance detector reaches a transmittance threshold.

[0015] Furthermore, the take-up and unwinding transport assembly is equipped with a voltage detector for monitoring the voltage drop across the metal foil, and the voltage detector is connected to a safety controller; the safety controller is configured to calculate the real-time resistance of the metal foil, and if the real-time resistance is within a certain range... If the current rises sharply within a short period of time, exceeding a set threshold, the conductive roller assembly is controlled to stop applying the adsorption current to the metal foil.

[0016] The second aspect of this application provides an etching method for a perforated foil for a solid-state battery current collector, employing the following technical solution: An etching method for a perforated foil for a solid-state battery current collector, based on the aforementioned etching equipment for a perforated foil for a solid-state battery current collector, includes the following steps: S1. Introducing a metal foil into the equipment at a preset linear velocity, so that it wraps around the porous drum at a preset angle without relative slippage; S2. Pumping magnetorheological etching liquid into the high-pressure injection stator to establish a supply pressure independent of the rotational speed of the porous drum; S3. Using the supply pressure to drive the magnetorheological etching liquid to penetrate the micropores of the porous drum and the metal foil for chemical etching; simultaneously, using an external magnetic field generating module to drive the magnetic abrasive in the magnetorheological etching liquid to grind the etching hole walls while penetrating the metal foil; S4. Etching waste liquid flies off the surface of the metal foil with the centrifugal force generated by the rotation of the porous drum and enters the circulation system; S5. Based on the online detection results of the transmittance of the etched metal foil, independently adjusting the supply pressure of the high-pressure injection stator and the linear velocity of the metal foil transmission.

[0017] In summary, the beneficial technical effects of this application are as follows: 1. By setting a microporous uniform flow sintering layer on the porous drum, a significant fluid rectification effect can be achieved, which can greatly improve the pore size consistency of the etched holes on the metal foil; moreover, the combination of the high-pressure liquid injection stator and the porous drum can make the etching jet impact the metal foil at a high vertical height, which can ensure the coaxiality of the etched holes; 2. The setting of the external magnetic field generating module enables the magnetic abrasive in the magnetorheological etching solution to dynamically grind the etched hole walls when etching the metal foil, which can improve the etching efficiency and ensure the verticality and smoothness of the etched holes, thus improving the controllability of the holes during etching; 3. The oleophobic treatment of the porous drum surface can prevent the magnetorheological etching solution from flowing out from the side of the metal foil and the porous drum bonding surface. The seepage direction can prevent residue and accelerate the removal of etching waste liquid, shorten the residence time of etching by-products near the orifice, and improve the phenomenon of over-etching or orifice enlargement caused by waste liquid adhering to the wall and backflow in traditional etching, so as to ensure highly controllable etching effect; 4. By applying an adsorption current along the transmission direction to the metal foil, the metal foil is subjected to a Lorentz force pointing towards the center of the porous drum, which can overcome the centrifugal force generated by the metal foil following the rotation of the porous drum, so that the metal foil is tightly adsorbed on the surface of the microporous uniform flow sintering layer of the porous drum, avoiding jet scattering and uneven etching caused by the small gap between the metal foil and the surface of the porous drum; and it can adapt to the micro-thickness changes of the metal foil, ensuring that the etching liquid can only be sprayed radially along the micropores without lateral flow. Attached Figure Description

[0018] Figure 1 is a cross-sectional view of the overall structure of an embodiment of this application; Figure 2 is a partially enlarged schematic diagram of part A in Figure 1; Figure 3 is a flowchart of the etching method of an embodiment of this application.

[0019] Explanation of reference numerals in the attached drawings: 1. Winding and unwinding conveyor assembly; 11. Conductive roller assembly; 12. Recycling tank; 2. Perforated drum; 21. Rigid support frame; 22. Microporous flow equalization sintered layer; 3. Metal foil; 4. High-pressure liquid injection stator; 41. Liquid injection port; 51. C-type magnetic yoke array; 52. High-frequency dynamic coil assembly; 6. Non-magnetic conductive mesh belt; 61. Conductive rubber layer; 7. Light transmittance meter. Detailed Implementation

[0020] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application discloses an etching apparatus for perforated foil of a solid-state battery current collector. Referring to Figures 1 and 2, it includes: a winding and unwinding conveying assembly 1, used to drive the metal foil 3 to be etched 3 to be continuously conveyed at a preset linear speed with constant tension; the assembly includes at least an unwinding roller, a winding roller, and several guide rollers, as well as a corresponding tension adjustment system. The unwinding roller, winding roller, guide rollers, and tension adjustment system are all prior art, and can be fully implemented by those skilled in the art, so further explanation is unnecessary.

[0022] The porous drum 2 is a hollow cylindrical structure with an array of micropores on its cylindrical surface. The rotational linear speed of the porous drum 2 is synchronized with the conveying linear speed of the metal foil 3, so that the metal foil 3 is relatively stationary and attached to the outer wall of the porous drum 2 at a preset wrap angle. The preset wrap angle is 60° to 120°. In this embodiment, 120° is used as an example.

[0023] The high-pressure liquid injection stator 4 is coaxially suspended in the internal cavity of the porous drum 2, and has a liquid injection port 41 only in the fan-shaped area corresponding to the covering angle of the metal foil 3, for continuously supplying high-pressure magnetorheological etching liquid to the inner wall of the rotating porous drum 2; specifically, it is set in a fan-shaped arrangement coaxial with the porous drum 2. The high-pressure liquid injection stator 4 has a stator cavity inside and is connected to the magnetorheological etching liquid source through pipes, pressurization pumps, etc. The liquid injection port 41 of the high-pressure liquid injection stator 4 points to the lower part or the side of the porous drum 2. In this embodiment, it points to the side. The magnetorheological etching solution generally comprises 70% base etching solution, 25% magnetic abrasive, and 5% suspension stabilizer and functional additives. The base etching solution is selected according to the foil material. For copper foil, a phosphoric acid or hydrochloric acid solution with a concentration of 3-5 mol / L is preferred; for aluminum foil, a sulfuric acid or hydrochloric acid solution with a concentration of 3-5 mol / L is preferred. The magnetic abrasive is spherical carbonyl iron powder with a particle size of 1-10 μm. The suspension stabilizer can be silica sol or nano-oxides (such as SiO2) modified with specific surfactants. The functional additives can be appropriate amounts of corrosion inhibitors (such as benzotriazole) to control lateral etching. The specific preparation method is a conventional technique in this field and will not be elaborated here.

[0024] An external magnetic field generating module is used to drive the magnetic abrasive in the magnetorheological etching solution to grind the etched hole wall as it penetrates the metal foil 3.

[0025] Specifically, the porous drum 2 includes, from the inside out, the following components arranged sequentially: a rigid support frame 21 with a highly permeable mesh structure, made of high-strength PEEK or ceramic material, which can provide strong support.

[0026] The microporous uniform flow sintering layer 22, sintered on the surface of the rigid support frame 21, serves as the bearing surface of the metal foil 3. Its micropore diameter is less than half the diameter of the aperture to be etched, and it is used to convert the macroscopic liquid flow from the high-pressure liquid injection stator 4 into micro-jet streams. In a specific example, the microporous uniform flow sintering layer 22 is formed by high-temperature sintering of alumina ceramic microspheres with an average particle size of 10–20 μm, creating a porous dielectric layer with a thickness of 0.5–1 mm. Therefore, when the magnetorheological etching solution output from the high-pressure liquid injection stator 4 impacts this layer, the enormous dynamic pressure is converted into a uniformly distributed static pressure, forcing the magnetorheological etching solution to be divided into billions of "micron-sized jets" that are extruded. This acts as a "micro-rectification" effect in fluid dynamics, eliminating turbulent pulsations caused by high-pressure liquid injection and ensuring that each jet of magnetorheological etching solution sprayed onto the back of the metal foil 3 has an extremely consistent velocity and direction, thus guaranteeing the uniformity of the aperture of the thousands of micropores on the metal foil 3.

[0027] Furthermore, the outer surface of the microporous flow equalization sintering layer 22 is mirror-polished and treated with an oleophobic coating to ensure a tight fit with the metal foil 3 and to prevent lateral leakage of the etching solution. Specifically, the outer surface of the microporous flow equalization sintering layer 22 is mirror-polished and coated with a perfluorosilane-based oleophobic coating to form an oleophobic surface. This prevents the etching waste liquid from spreading and adhering to the surface of the porous drum 2. Once it penetrates the metal foil 3, the etching waste liquid will instantly detach in the form of spherical droplets under centrifugal force, greatly reducing the liquid residence time near the orifice and preventing the orifice enlargement caused by "over-etching".

[0028] Furthermore, the etching equipment of this application also includes a recycling tank 12 for collecting etching waste liquid. The external magnetic field generating module is encapsulated in a corrosion-resistant non-metallic package. The recycling tank 12 has several baffles to guide the etching waste liquid after the etching process is completed to the recycling tank 12 and avoid repeated contamination of the metal foil 3.

[0029] Therefore, during the etching process of the metal foil 3, the take-up and unwinding conveyor assembly 1 steadily conveys the metal foil 3 to be etched at a constant speed. Under the guidance of the guide rollers in the take-up and unwinding conveyor assembly 1, the metal foil 3 is tightly adhered to the outer wall of the high-speed rotating porous drum 2 at a preset wrap angle. The rotational linear velocity of the porous drum 2 is strictly synchronized with the conveying speed of the metal foil 3, ensuring that there is no relative slippage between the two in the etching area. At the same time, the high-pressure liquid injection stator 4 is coaxially suspended and fixed in the inner cavity of the porous drum 2. Its injection port 41 is only aligned with the covering area of ​​the metal foil 3. The pressurized pump injects the specially made magnetorheological etching liquid into the stator cavity at a certain pressure and sprays it onto the inner wall of the porous drum 2 through the injection port 41. Under the pressure drive, the magnetorheological etching liquid penetrates the micropore array on the drum wall, forming countless high-speed, directional micro-beam jets that vertically impact the back of the metal foil 3 adhered to the outer wall of the porous drum 2, thus initiating the chemical etching process.

[0030] At the same time, the external magnetic field generating module applies a high-intensity, controllable magnetic field to the etching area of ​​the porous drum 2 corresponding to the high-pressure liquid injection stator 4. This magnetic field instantly magnetizes and chains the magnetic abrasive in the magnetorheological etching solution, and performs high-frequency micro-grinding on the forming hole wall under the drive of a specific magnetic field mode. The etching waste liquid is quickly thrown away under the combined action of centrifugal force and the oleophobic properties of the porous drum 2 surface, and the perforated foil that has completed etching is wound up by the take-up roller.

[0031] Therefore, the microporous uniform flow sintering layer 22 can achieve a significant fluid rectification effect, greatly improving the pore size consistency of the etched holes on the metal foil 3. Moreover, the cooperation between the high-pressure liquid injection stator 4 and the porous drum 2 allows the etching jet to impact the metal foil 3 at a high vertical height, ensuring the coaxiality of the etched holes. In addition, the setting of the external magnetic field generating module enables the magnetic abrasive in the magnetorheological etching solution to dynamically grind the etched hole walls during the etching of the metal foil 3, which can improve etching efficiency and ensure the verticality and smoothness of the etched holes, thus improving the controllability of the holes during etching. Furthermore, the oleophobic treatment of the porous drum 2 surface can prevent the magnetorheological etching solution from leaking from the side of the bonding surface between the metal foil 3 and the porous drum 2. On the one hand, it can prevent residue, and on the other hand, it can accelerate the removal of etching waste liquid and shorten the residence time of etching by-products near the hole opening. This improves the phenomenon of over-etching or hole enlargement caused by waste liquid hanging on the wall and backflow in traditional etching, thus ensuring a highly controllable etching effect.

[0032] To improve the stability of the magnetorheological etching solution during the impact etching of the metal foil 3, referring to Figures 1 and 2, the take-up and unwinding transport assembly 1 also includes two conductive roller groups 11 arranged on both sides of the porous drum 2. The two conductive roller groups 11 are used to apply an adsorption current along the transport direction to the metal foil 3 which is attached to the outer wall of the porous drum 2 at a preset wrap angle. The external magnetic field generating module is also configured to generate an adsorption magnetic field parallel to the axis of the porous drum 2. The adsorption magnetic field and the adsorption current work together to generate a Lorentz force on the metal foil 3 pointing towards the center of the porous drum 2, so that the metal foil 3 is electromagnetically adsorbed onto the surface of the porous drum 2.

[0033] Furthermore, the minimum adsorption current applied to the metal foil 3 by the conductive roller assembly 11 satisfies: ;in, As a preset safety factor, and ; Let be the areal density of metal foil 3. The rotational angular velocity of the perforated drum 2 For a multi-hole drum with a radius of 2, The effective width of metal foil 3, The magnetic field strength is the adsorption magnetic field. Thus, the Lorentz force applied to the metal foil 3 is greater than the centrifugal force it experiences when following the porous drum 2, ensuring a non-contact adsorption effect of the metal foil 3 on the outer wall of the porous drum 2 under the cooperation of the adsorption current and the external magnetic field generating module.

[0034] Specifically, referring to Figures 1 and 2, the external magnetic field generating module includes: a C-shaped magnetic yoke array 51, which covers the outer side of the etching area along the circumference of the porous drum 2, with its two poles pointing to the two ends of the axis of the porous drum 2, for generating an adsorption magnetic field; and a high-frequency dynamic coil group 52, which is embedded in the magnetic pole surface of the C-shaped magnetic yoke array 51 and connected to a high-frequency AC power supply with an output frequency of 20kHz to 50kHz, for superimposing and generating an AC pulse magnetic field perpendicular to the surface of the metal foil 3. The AC pulse magnetic field is used to drive the magnetic abrasive in the magnetorheological etching solution to generate reciprocating oscillation and rotational motion, and dynamically grind the etching hole wall.

[0035] Further, referring to Figures 1 and 2, a non-magnetic conductive mesh belt 6 is provided between the external magnetic field generating module and the porous drum 2. The non-magnetic conductive mesh belt 6 is configured to physically press the metal foil 3 onto the outer surface of the porous drum 2 in the etched coverage area of ​​the metal foil 3, and is synchronously conveyed with the metal foil 3 and the porous drum 2 at the same angular velocity. In another feasible embodiment, a conductive rubber layer 61 with dense pores is provided on the side of the non-magnetic conductive mesh belt 6 that contacts the metal foil 3, and the non-magnetic conductive mesh belt 6 makes conductive contact with the metal foil 3 through the conductive rubber layer 61. Specifically, the non-magnetic conductive mesh belt 6 presses the metal foil 3 between the two guide rollers in the take-up and unwinding conveyor assembly 1 onto the outer wall of the porous drum 2 with an angle of wrapping not greater than a preset wrapping angle. The metal foil 3 can be connected to the adsorption current through electrical contact with the non-magnetic conductive mesh belt 6, or it can be connected to the adsorption current through the two conductive roller groups 11. In this embodiment, the two conductive roller groups 11 are part of the non-magnetic conductive mesh belt 6 conveyor roller group.

[0036] Thus, under the synergistic effect of the conductive roller group 11 and the non-magnetic conductive mesh belt 6, the metal foil 3 is subjected to an adsorption current along the transmission direction. At the same time, the C-type magnetic yoke array 51 generates an adsorption magnetic field parallel to the axis of the porous drum 2. According to the left-hand rule, the metal foil 3 is subjected to a Lorentz force pointing towards the center of the porous drum 2, which can overcome the centrifugal force generated by the metal foil 3 following the rotation of the porous drum 2, so that the metal foil 3 is tightly adsorbed on the surface of the microporous uniform flow sintering layer 22 of the porous drum 2, avoiding jet scattering and uneven etching caused by the small gap between the metal foil 3 and the surface of the porous drum 2. Furthermore, a non-magnetic conductive mesh belt 6 with a conductive rubber layer 61 is provided to physically compress the metal foil 3 and conduct electricity synchronously.

[0037] The considerations are as follows: Under high-speed rotation and high-pressure liquid flow impact, mechanical tension alone cannot guarantee a comprehensive, gapless, and stable conductive adhesion between the metal foil 3 and the surface of the rotating porous drum (especially the microporous area). Any tiny gap will cause the etching solution micro-jet to diverge, destroying the hole shape. In the above scheme, non-contact uniform electromagnetic adsorption is achieved through Lorentz force, and contact pressure equalization and shape preservation are achieved through non-magnetic conductive mesh belt 6. This dual guarantee mechanism is extremely ingenious and can effectively ensure that the physical state of the etching reaction interface (between the metal foil 3 and the microporous uniform flow sintering layer 22) is extremely stable. This lays an indispensable physical foundation for the precise transmission of the micro-jet and the control of the hole shape, and can adapt to the microscopic thickness changes of the metal foil 3, ensuring that the etching solution can only be sprayed radially along the micropores without lateral flow.

[0038] Furthermore, referring to Figure 1, a transmittance detector 7 is installed downstream of the take-up and unwinding transport assembly 1. The transmittance detector 7 is connected to an inspection controller. The inspection controller is configured to control the high-pressure liquid injection stator 4 to increase the liquid supply pressure and / or control the take-up and unwinding transport assembly 1 and the multi-hole drum 2 to synchronously reduce the conveying speed when the transmittance detected by the transmittance detector 7 reaches the transmittance threshold. This ensures that the number and diameter of the etched holes meet production requirements.

[0039] Furthermore, the take-up and unwinding conveyor assembly 1 is equipped with a voltage detector for monitoring the voltage drop across the metal foil 3. The voltage detector is connected to a safety controller. The safety controller is configured to calculate the real-time resistance of the metal foil 3. If the real-time resistance rises sharply within a time period exceeding a set threshold, the conductive roller assembly 11 is controlled to stop applying the adsorption current to the metal foil 3. This allows the adsorption current to be cut off within microseconds before the metal foil 3 melts (resistance rises sharply), preventing high-energy electric sparks from damaging the expensive insulating porous drum 2 and improving safety during equipment production.

[0040] This application discloses an etching method for a perforated foil for a solid-state battery current collector. Based on the above-mentioned etching equipment for a perforated foil for a solid-state battery current collector, referring to Figure 1, the method includes the following steps: S1. Introducing a metal foil 3 into the equipment at a preset linear velocity, so that it covers the porous drum 2 at a preset wrap angle without relative slippage; S2. Pumping magnetorheological etching liquid into the high-pressure injection stator 4 to establish a liquid supply pressure independent of the rotational speed of the porous drum 2; S3. Using the liquid supply pressure to drive the magnetorheological etching liquid to penetrate the micropores of the porous drum 2. Chemical etching is performed on the metal foil 3. At the same time, the external magnetic field generating module drives the magnetic abrasive in the magnetorheological etching solution to grind the etching hole wall when penetrating the metal foil 3, and drives the metal foil 3 to be adsorbed onto the porous drum 2 by Lorentz force. S4. The etching waste liquid flies away from the surface of the metal foil 3 by the centrifugal force generated by the rotation of the porous drum 2 and enters the circulation system. S5. According to the online detection results of the light transmittance of the metal foil 3 after etching, the liquid supply pressure of the high-pressure liquid injection stator 4 and the transmission line speed of the metal foil 3 are independently adjusted.

[0041] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An etching apparatus for perforated foil for current collectors in solid-state batteries, characterized in that, include: The system includes a winding and unwinding conveyor assembly for continuously conveying the metal foil to be etched at a preset linear speed; a porous drum, a hollow cylindrical structure with an array of micropores on its cylindrical surface, the rotating linear speed of the porous drum being synchronized with the conveying linear speed of the metal foil, so that the metal foil is relatively stationary against the outer wall of the porous drum at a preset wrap angle; a high-pressure liquid injection stator, coaxially suspended in the cavity inside the porous drum, with liquid injection ports only in the fan-shaped area corresponding to the wrap angle of the metal foil, for continuously supplying high-pressure magnetorheological etching solution to the inner wall of the rotating porous drum; and an external magnetic field generating module for driving the magnetic abrasive in the magnetorheological etching solution to grind the etching hole wall as it penetrates the metal foil.

2. The etching equipment for perforated foil for solid-state battery current collectors according to claim 1, characterized in that, The porous drum comprises, from the inside out, the following components arranged sequentially: a rigid support frame with a highly permeable mesh structure; a microporous flow equalization sintered layer sintered on the surface of the rigid support frame, serving as a bearing surface for the metal foil, wherein the micropore diameter is less than 1 / 2 of the aperture to be etched, used to convert the macroscopic liquid flow from the high-pressure liquid injection stator into a micro-jet stream; the outer surface of the microporous flow equalization sintered layer is mirror polished and oleophobic to ensure tight adhesion to the metal foil and prevent lateral leakage of the etching solution.

3. The etching equipment for perforated foil for solid-state battery current collectors according to claim 1, characterized in that, The take-up and unwinding transport assembly includes two sets of conductive rollers arranged on both sides of the porous drum. The two sets of conductive rollers are used to apply an adsorption current along the transport direction to the metal foil that is attached to the outer wall of the porous drum at a preset wrap angle. The external magnetic field generating module is also configured to generate an adsorption magnetic field parallel to the axis of the porous drum. The adsorption magnetic field and the adsorption current work together to generate a Lorentz force on the metal foil pointing towards the center of the porous drum, so that the metal foil is electromagnetically adsorbed onto the surface of the porous drum.

4. The etching equipment for perforated foil for solid-state battery current collectors according to claim 3, characterized in that, The minimum adsorption current applied to the metal foil by the conductive roller assembly satisfies: ;in, As a preset safety factor, and ； Let be the areal density of the metal foil. The rotational angular velocity of the porous drum is... The radius of the multi-hole drum, The effective width of the metal foil, The magnetic field strength of the adsorption magnetic field is given.

5. The etching equipment for perforated foil for solid-state battery current collectors according to claim 4, characterized in that, The external magnetic field generating module includes: a C-shaped magnetic yoke array, which covers the outer side of the etching area along the circumference of the porous drum, with its two poles pointing to the two ends of the axis of the porous drum, for generating the adsorption magnetic field; and a high-frequency dynamic coil group, which is embedded in the magnetic pole surface of the C-shaped magnetic yoke array, for superimposing and generating an AC pulse magnetic field perpendicular to the surface of the metal foil. The AC pulse magnetic field is used to drive the magnetic abrasive in the magnetorheological etching solution to generate reciprocating oscillation and rotational motion, and dynamically grind the etching hole wall.

6. The etching equipment for perforated foil for solid-state battery current collectors according to claim 1, characterized in that, A non-magnetic conductive mesh belt is provided between the external magnetic field generating module and the porous drum. The non-magnetic conductive mesh belt is configured to physically press the metal foil onto the outer surface of the porous drum in the etched area of ​​the metal foil, and to synchronously transport the metal foil and the porous drum at the same angular velocity.

7. The etching apparatus for perforated foil for solid-state battery current collectors according to claim 6, characterized in that, A conductive rubber layer is provided on the side of the non-magnetic conductive mesh belt that contacts the metal foil.

8. The etching equipment for perforated foil for solid-state battery current collectors according to claim 1, characterized in that, A transmittance detector is installed downstream of the winding and unwinding conveyor assembly, and the transmittance detector is connected to an inspection controller; the inspection controller is configured to control the high-pressure liquid injection stator to increase the liquid supply pressure and / or control the winding and unwinding conveyor assembly and the multi-hole drum to synchronously reduce the conveying speed when the transmittance detected by the transmittance detector reaches a transmittance threshold.

9. The etching equipment for perforated foil for solid-state battery current collectors according to claim 3, characterized in that, The winding and unwinding transport assembly is equipped with a voltage detector for monitoring the voltage drop across the metal foil. The voltage detector is connected to a safety controller. The safety controller is configured to calculate the real-time resistance of the metal foil. If the real-time resistance is within a certain range... If the current rises sharply within a short period of time, exceeding a set threshold, the conductive roller assembly is controlled to stop applying the adsorption current to the metal foil.

10. A method for etching a perforated foil for a solid-state battery current collector, based on an etching apparatus for a perforated foil for a solid-state battery current collector as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Introduce the metal foil into the device at a preset linear velocity, so that it wraps around the porous drum at a preset wrap angle without relative slippage; S2. Pump magnetorheological etching solution into the high-pressure injection stator to establish a liquid supply pressure independent of the rotational speed of the porous drum; S3. The magnetorheological etching solution is driven by the liquid supply pressure to penetrate the micropores of the porous drum and the metal foil for chemical etching; at the same time, the magnetic abrasive in the magnetorheological etching solution is driven by the external magnetic field generating module to grind the etching hole wall when penetrating the metal foil. S4. The etching waste liquid is ejected from the metal foil surface by the centrifugal force generated by the rotation of the porous drum and enters the recycling system; S5. Based on the online detection results of the transmittance of the etched metal foil, independently adjust the liquid supply pressure of the high-pressure liquid injection stator and the linear speed of the metal foil transmission.

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