One-stop lithium battery separator interface processing device and processing method

Abstract

The present invention discloses a one-stop lithium battery diaphragm interface treatment device and treatment method. The diaphragm to be treated passes through a cleaning chamber, a reduction chamber, and a deposition chamber in sequence via a conveyor belt. The cleaning chamber includes an inlet for introducing a sample into the diaphragm and a spray gun for spraying liquid on the surface of the diaphragm. The reduction chamber includes a first conveying port connected to the cleaning chamber, a high-voltage electrode, an air inlet for inputting a reducing gas, a first gas tank connected to the air inlet, and a first air outlet. The deposition chamber includes a second conveying port connected to the reduction chamber, a plate electrode for ionizing the gas, a second gas tank connected to the plate electrode, a second air outlet, and a sample outlet. The battery diaphragm treated by the present invention can form a SEI layer with high ionic conductivity and high electronic insulation after the battery is assembled, which helps to achieve uniform lithium deposition during battery operation and inhibit the growth of lithium dendrites.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium batteries, and in particular relates to a one-stop lithium battery diaphragm interface processing device. Background Art

[0002] For a long time, the growth of dendrites inside batteries has been a major problem that has plagued industry and academia in achieving high-energy-density, high-safety metal battery energy storage devices. Lithium dendrite growth not only causes a decrease in battery capacity and accelerated decay, but can also pierce the separator, causing contact between the positive and negative poles of the battery and triggering a series of adverse events such as thermal runaway (fire, smoke, explosion). If not properly handled, the impact can be far-reaching: in academia and industry, it can seriously hinder breakthroughs in high-energy-density energy storage devices and stagnate technological development; in the public sphere, adverse events can damage consumer confidence in new energy products. Therefore, fundamentally solving the problem of dendrite growth inside batteries is of great significance.

[0003] The physical and chemical properties of the solid electrolyte interface (SEI) layer in the electrode formed during battery cycling have a direct impact on dendrite growth. In short, an ideal SEI layer needs to have high ionic conductivity to facilitate the rapid passage of lithium and sodium ions through the SEI layer, while also having high electronic insulation to effectively prevent electrons from passing through the SEI layer, thereby effectively inhibiting dendrite growth.

[0004] At the same time, studies have shown that metal elements such as copper, aluminum, silver, and tin can spontaneously alloy with lithium to form Li x M y The lithium-metal alloy facilitates the rapid diffusion of lithium ions through the SEI layer. Electronegative elements such as fluorine and nitrogen react chemically with lithium to form highly electron-insulating compounds such as lithium nitride and lithium fluoride, inhibiting the shuttling of electrons across the SEI layer. Therefore, researchers have successfully constructed this ideal SEI layer by processing the battery separator to deposit a composite protective layer of metal and electronegative elements on its surface. Common methods include chemical coating, magnetron sputtering, and vapor deposition. However, these methods all have drawbacks, such as high energy consumption, long processing times, and uneven loading.

[0005] Plasma, the fourth state of matter, is an electrically neutral conductive fluid. Conventional methods for generating plasma include glow discharge, radio frequency discharge, and dielectric barrier discharge. Plasma contains a large number of high-energy electrons and reactive radicals, including hydroxyl radicals, hydrogen radicals, and ozone. These high-energy electrons and reactive radicals can continuously collide with matter, altering not only its morphology, structure, and other physical properties, but also its chemical properties. Summary of the Invention

[0006] The main technical problem solved by the present invention is to provide a one-stop lithium battery separator interface treatment device and treatment method. The battery separator treated by the present invention can form an SEI layer with high ionic conductivity and high electronic insulation after the battery is assembled, which helps to achieve uniform lithium deposition during battery operation and inhibit the growth of lithium dendrites.

[0007] To solve the above technical problems, the present invention adopts a technical solution: a one-stop lithium battery diaphragm interface treatment device, comprising a chamber, wherein the chamber is divided into a cleaning chamber, a reduction chamber, and a deposition chamber, and the diaphragm to be treated passes through the cleaning chamber, the reduction chamber, and the deposition chamber in sequence via a conveyor belt;

[0008] The cleaning chamber includes an inlet for introducing a sample into the diaphragm and a spray gun for spraying liquid on the surface of the diaphragm;

[0009] The reduction chamber includes a first conveying port connected to the cleaning chamber, a high-voltage electrode, an air inlet for inputting reducing gas, a first gas tank connected to the air inlet, and a first air outlet; the high-voltage electrode is connected to the high-voltage end of the power supply through a high-voltage wire, and the low-voltage end of the power supply is connected to the conveyor belt through a wire;

[0010] The deposition chamber includes a second transfer port connected to the reduction chamber, a plate electrode for ionizing the gas, a second gas tank connected to the plate electrode, a second gas outlet and a sample outlet;

[0011] It also includes a controller, and the conveyor belt, the spray gun, the high-voltage electrode, the power supply, the plate electrode, the first gas tank and the second gas tank are electrically connected to the controller respectively.

[0012] Furthermore, the reduction chamber further includes a first gas pressure sensor for monitoring the internal pressure of the reduction chamber and a temperature sensor for monitoring the internal temperature of the reduction chamber. The first gas pressure sensor and the temperature sensor are electrically connected to the controller respectively.

[0013] Furthermore, the deposition chamber further includes a second gas pressure sensor for monitoring the internal pressure of the deposition chamber, and the second gas pressure sensor is electrically connected to the controller.

[0014] Furthermore, the first air outlet and the second air outlet are respectively connected to a fan, and the fan is electrically connected to the controller.

[0015] A one-stop lithium battery separator interface treatment method includes the following steps:

[0016] 1) The membrane to be processed is fed into the chamber through the inlet, and the conveyor belt provides power to achieve continuous processing of the membrane;

[0017] 2) The liquid containing the metal compound is sprayed from the spray gun, forming droplets of different sizes according to the requirements and sprayed on the surface of the diaphragm; the conveyor belt has a heating function to dry the diaphragm;

[0018] 3) The diaphragm treated in step 2) is conveyed from the first conveying port to the next area. The high-voltage electrode is connected to the high-voltage terminal of the power supply via a high-voltage wire, and the low-voltage terminal of the power supply is connected to the conveyor belt. The reducing gas in the first gas tank enters the cavity through the air inlet. When a high voltage is applied, a low-temperature plasma containing hydrogen free radicals and argon free radicals is generated, reducing the metal compound loaded in step 2) to a single substance. At the same time, under the protection of the reducing gas, the metal single substance is prevented from being oxidized in the air.

[0019] 4) The diaphragm treated in step 3) enters the next area through the second transfer port. The seed gas containing the electronegative element in the second gas tank is ionized into its corresponding compound during the process of passing through the plate electrode, and is evenly loaded on the diaphragm treated in step 3). At this point, the surface of the diaphragm is now filled with both the metal element and the electronegative element.

[0020] 5) The treated membrane is sent out of the cavity through the sample outlet, which can realize continuous treatment; the residence time can also be set, and the residence time is 30 seconds to 5 minutes.

[0021] Furthermore, the metal compound in step 2) is silver nitrate, nickel nitrate or copper chloride.

[0022] Furthermore, the reducing gas in step 3) is at least one of hydrogen and argon.

[0023] Furthermore, the high voltage of step 3) is 10-50 kV.

[0024] Furthermore, the seed gas containing electronegative elements in step 4) is carbon fluoride, nitrogen oxide or ammonia.

[0025] The beneficial effects of the present invention include at least the following:

[0026] 1. This invention integrates two major functions of low-temperature plasma technology into one: 1. Reducing metal compounds to their corresponding elemental forms and loading them on the diaphragm surface; 2. Loading electronegative elements in the gas phase on the diaphragm surface through chemical deposition;

[0027] 2. Unlike conventional methods that are limited by the types of compounds and target materials, the present invention can achieve a wider variety of metal-electronegative element combinations on the diaphragm;

[0028] 3. The present invention not only provides an appropriate process flow, but also provides a feasible device design idea for large-scale production;

[0029] 4. The battery separator treated by the present invention can form a SEI layer with high ionic conductivity and high electronic insulation after assembling the battery, which helps to achieve uniform lithium deposition during battery operation and inhibit the growth of lithium dendrites;

[0030] 5. The battery separator treated by the present invention is assembled into a ternary lithium battery, which has excellent electrochemical performance, including: higher initial specific capacity (>180mAh / g, 0.5C) and higher capacity retention rate (>99%, 100 cycles);

[0031] 6. Stable internal air pressure and temperature of the entire device are the prerequisites for the normal operation of the device. The internal pressure is monitored by the gas pressure sensor, the internal pressure is adjusted by the fan, and the internal temperature is monitored by the temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the processing device of the present invention. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0034] Example: A one-stop lithium battery separator interface processing device, such as Figure 1 As shown, it includes a chamber 1, which is divided into a cleaning chamber, a reduction chamber and a deposition chamber. The diaphragm to be treated passes through the cleaning chamber, the reduction chamber and the deposition chamber in sequence through a conveyor belt 4;

[0035] The cleaning chamber comprises an inlet 2 for introducing a sample into the diaphragm and a spray gun 3 for spraying liquid on the surface of the diaphragm;

[0036] The reduction chamber includes a first conveying port 5 connected to the cleaning chamber, a high-voltage electrode 6, an air inlet 9 for inputting reducing gas, a first gas tank 10 connected to the air inlet, and a first air outlet 12; the high-voltage electrode is connected to the high-voltage end of the power supply 8 via a high-voltage wire 7, and the low-voltage end of the power supply is connected to the conveyor belt via a wire;

[0037] The deposition chamber includes a second transfer port 15 connected to the reduction chamber, a plate electrode 16 for ionizing the gas, a second gas tank 17 connected to the plate electrode, a second gas outlet 19 and a sample outlet 20;

[0038] It also includes a controller, and the conveyor belt, the spray gun, the high-voltage electrode, the power supply, the plate electrode, the first gas tank and the second gas tank are electrically connected to the controller respectively.

[0039] The reduction chamber further includes a first gas pressure sensor 11 for monitoring the internal pressure of the reduction chamber and a temperature sensor 14 for monitoring the internal temperature of the reduction chamber. The first gas pressure sensor and the temperature sensor are electrically connected to the controller respectively.

[0040] The deposition chamber further includes a second gas pressure sensor 18 for monitoring the pressure inside the deposition chamber. The second gas pressure sensor is electrically connected to the controller.

[0041] The first air outlet and the second air outlet are respectively connected to a fan 13 , and the fan is electrically connected to the controller.

[0042] The processing process of the device includes the following steps:

[0043] 1) The membrane to be processed is fed into the chamber 1 through the sample inlet, and the conveyor belt 4 provides power to achieve continuous processing of the membrane;

[0044] 2) A liquid containing a metal compound is sprayed from a spray gun 3 to form droplets of different sizes as required and sprayed onto the surface of the diaphragm; a conveyor belt is provided with a heating function to dry the diaphragm; the metal compound can be an aqueous solution corresponding to a metal compound (such as silver nitrate, nickel nitrate, copper chloride, etc.), or dissolved in other liquids such as ethanol, NMP, DMF, etc.;

[0045] 3) The diaphragm treated in step 2) is conveyed to the next area via a first conveyor port 5. A high-voltage electrode 6 is connected to the high-voltage terminal of a power supply 8 via a high-voltage conductor 7. The low-voltage terminal of the power supply is connected to a conveyor belt. Reducing gas in a first gas tank 10 enters the chamber via an air inlet 9. A high voltage is applied to generate a low-temperature plasma containing hydrogen and argon radicals, reducing the metal compound loaded in step 2) to its elemental form. Simultaneously, under the protection of the reducing gas, oxidation of the elemental metal in air is prevented. The reducing gas is at least one of hydrogen and argon. The high voltage is 10-50 kV.

[0046] 4) The diaphragm treated in step 3) enters the next area through the second delivery port 15. The seed gas containing the electronegative element in the second gas tank 17 is ionized into its corresponding compound during the process of passing through the plate electrode 16, and is evenly loaded on the diaphragm treated in step 3. At this point, the diaphragm surface is coexisting with the metal element and the electronegative element. The seed gas containing the electronegative element is carbon fluoride, nitrogen oxide, or ammonia.

[0047] 5) The treated membrane is sent out of the cavity through the sample outlet 20, which can achieve continuous treatment; the residence time can also be set, and the residence time is 30 seconds to 5 minutes.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A one-stop lithium battery separator interface treatment device, characterized by: The method comprises a chamber (1), wherein the chamber is divided into a cleaning chamber, a reduction chamber, and a deposition chamber, and the diaphragm to be treated passes through the cleaning chamber, the reduction chamber, and the deposition chamber in sequence via a conveyor belt (4); The cleaning chamber comprises an inlet (2) for introducing a sample into the diaphragm and a spray gun (3) for spraying liquid onto the surface of the diaphragm, wherein the spray gun sprays liquid containing dissolved metal compounds; The reduction chamber comprises a first conveying port (5) connected to the cleaning chamber, a high-voltage electrode (6), an air inlet (9) for inputting reducing gas, a first gas tank (10) connected to the air inlet, and a first air outlet (12); the high-voltage electrode is connected to the high-voltage end of the power supply (8) via a high-voltage wire (7), and the low-voltage end of the power supply is connected to the conveyor belt via a wire; The deposition chamber comprises a second transmission port (15) connected to the reduction chamber, a plate electrode (16) for ionizing the gas, a second gas tank (17) connected to the plate electrode, a second gas outlet (19) and a sample outlet (20); The invention also includes a controller, wherein the conveyor belt, the spray gun, the high-voltage electrode, the power supply, the plate electrode, the first gas tank and the second gas tank are electrically connected to the controller respectively, and the second gas tank contains a seed gas of an electronegative element; The reduction chamber further comprises a first gas pressure sensor (11) for monitoring the internal pressure of the reduction chamber and a temperature sensor (14) for monitoring the internal temperature of the reduction chamber, wherein the first gas pressure sensor and the temperature sensor are electrically connected to the controller respectively; The deposition chamber further comprises a second gas pressure sensor (18) for monitoring the pressure inside the deposition chamber, and the second gas pressure sensor is electrically connected to the controller.

2. The one-stop lithium battery separator interface treatment device according to claim 1, characterized in that: The first air outlet and the second air outlet are respectively connected to a fan (13), and the fan is electrically connected to the controller.

3. A one-stop lithium battery separator interface treatment method, characterized by: The following steps are involved: 1) The diaphragm to be processed is fed into the chamber through the inlet, and the conveyor belt provides power to achieve continuous processing of the diaphragm; 2) Liquid containing metal compounds is sprayed from a spray gun, forming droplets of different sizes as required and sprayed onto the surface of the diaphragm; the conveyor belt has a heating function to dry the diaphragm; 3) The diaphragm treated in step 2) is conveyed from the first conveyor port to the next area. The high-voltage electrode is connected to the high-voltage terminal of the power supply via a high-voltage conductor, and the low-voltage terminal of the power supply is connected to the conveyor belt. The reducing gas in the first gas tank enters the cavity through the gas inlet. When a high voltage is applied, a low-temperature plasma containing hydrogen and argon radicals is generated, reducing the metal compound loaded in step 2) to a single substance. At the same time, under the protection of the reducing gas, the metal is prevented from being oxidized in the air. 4) The diaphragm treated in step 3) enters the next area through the second transfer port. The seed gas containing the electronegative element in the second gas tank is ionized into its corresponding compound during the process of passing through the plate electrode, and is evenly loaded on the diaphragm treated in step 3) at this point. At this point, the surface of the diaphragm is already filled with both metal elements and electronegative elements. 5) The treated membrane is sent out of the cavity through the sample outlet, which can realize continuous treatment; the residence time can also be set, and the residence time is 30 seconds to 5 minutes.

4. The one-stop lithium battery separator interface processing method according to claim 3, characterized in that: The metal compound in step 2) is silver nitrate, nickel nitrate or copper chloride.

5. The one-stop lithium battery separator interface processing method according to claim 3, characterized in that: The reducing gas in step 3) is at least one of hydrogen and argon.

6. The one-stop lithium battery separator interface processing method according to claim 3, characterized in that: The high voltage in step 3) is 10-50 kV.

7. The one-stop lithium battery separator interface processing method according to claim 3, characterized in that: The seed gas containing electronegative elements in step 4) is carbon fluoride, nitrogen oxide or ammonia.

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