A silicon-carbon anode nitriding method and nitrided anode sheet based on low-temperature ionization fluidization equipment

Abstract

This disclosure provides a silicon-carbon anode nitriding method and a nitrided anode sheet based on a low-temperature ionization fluidized bed device. The method includes: injecting nitrogen into a reaction chamber via a nitrogen injection pipeline to mix an ammonia-nitrogen mixture with carbonaceous raw materials; ionizing the ammonia-nitrogen mixture using a low-temperature plasma electrode to obtain nitrogen ions; fluidizing the nitrogen ions in the reaction chamber to allow them to diffuse into the carbonaceous raw materials, resulting in nitrided carbon; and performing a composite hybridization process on silicon powder and nitrided carbon to obtain a nitrided anode coating slurry. The low-temperature plasma electrode can obtain a large amount of nitrogen ions with lower energy consumption and more easily. The nitrogen ions then enter the framework of the carbonaceous raw materials through collisional doping to obtain nitrided carbon, and the nitrided carbon is then composite-hybridized with silicon powder to obtain the nitrided anode coating slurry.

Description

Technical Field

[0001] This disclosure relates to the technical field of battery electrode manufacturing, and in particular to a method for nitriding silicon-carbon anodes based on low-temperature ionization fluidization equipment and a nitrided anode sheet. Background Technology

[0002] To improve the volume stability, conductivity, and electrochemical performance of silicon-carbon anode materials, most manufacturers use nitrogen atom doping modification, that is, to embed nitrogen atoms into the carbon skeleton of silicon-carbon anodes, thereby changing the carbon skeleton structure and using the negative charge of nitrogen atoms to improve the electron transport efficiency and chemical reactivity of silicon-carbon anodes.

[0003] Existing nitrogen doping preparation technologies are mainly divided into three categories: pre-doping, post-doping, and direct pyrolysis. However, the pre-doping method has the limitation of being difficult to scale up production, the post-doping method has the problems of low nitrogen doping amount and poor uniformity, and the direct pyrolysis method is prone to causing a large loss of active nitrogen. In addition, the above nitrogen doping methods mostly rely on non-environmentally friendly materials such as nitric acid, ammonia, and urea. Due to the limitations of the properties of the raw materials themselves, the release of nitrogen ions is difficult, the process has high energy consumption, and the environmental pollution is strong. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a silicon-carbon anode nitriding method and a nitrided anode sheet based on a low-temperature ionization fluidization device that features rapid nitrogen ion release, low energy consumption, and low pollution.

[0005] The purpose of this disclosure is achieved through the following technical solution: A method for nitriding a silicon-carbon anode based on a low-temperature ionization fluidization device, characterized in that it is performed using a low-temperature ionization fluidization device, the low-temperature ionization fluidization device comprising: A reaction silo, which is used to contain carbonaceous raw materials; A nitrogen injection pipeline, wherein the nitrogen injection pipeline is connected to the reaction silo, and the nitrogen injection pipeline is used to introduce an ammonia-nitrogen mixture into the reaction silo; and A low-temperature plasma electrode is disposed in the reaction chamber and is used to ionize the ammonia-nitrogen mixture. The silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment includes the following steps: Nitrogen is injected into the reaction silo through the nitrogen injection pipeline to mix the ammonia-nitrogen mixture with the carbonaceous raw material. The ammonia-nitrogen mixture is ionized using the low-temperature plasma electrode to obtain nitrogen ions. The nitrogen ions are fluidized and doped through the reaction silo to allow the nitrogen ions to diffuse into the carbonaceous raw material to obtain nitrided carbonaceous material. The silicon powder and the nitrided carbonaceous material are subjected to a composite mixing process to obtain a nitrided negative electrode coating slurry.

[0006] In some embodiments, the following steps are included before the nitrogen injection treatment step: The ammonia-nitrogen mixture is obtained by mixing nitrogen gas with ammonia water.

[0007] In some embodiments, the temperature of the ammonia water is 45°C to 65°C.

[0008] In some embodiments, the low-temperature ionization fluidization apparatus further includes a microwave emitting device disposed within the reaction hopper, the microwave emitting device being used to heat the carbonaceous raw material.

[0009] In some embodiments, the following steps are included before the nitrogen injection treatment step: The carbonaceous raw material is heated and activated by the microwave emitting device to increase its temperature.

[0010] In some embodiments, the low-temperature ionization fluidization device further includes an electromagnetic fluidization component disposed on the outer periphery of the reaction hopper, the electromagnetic fluidization component being used to fluidize the nitrogen ions.

[0011] In some embodiments, the following steps are included prior to the fluidization doping treatment step: The nitrogen ions are fluidized and accelerated by the electromagnetic fluidization component to increase their movement speed.

[0012] In some embodiments, the electromagnetic fluidization assembly includes a plurality of electromagnets spaced apart around the outer periphery of the reaction hopper.

[0013] In some embodiments, the nitrogen injection pipeline and the low-temperature plasma electrode are both located at the bottom of the reaction chamber; the outlet of the nitrogen injection pipeline is connected to the bottom of the reaction chamber and distributed around the outer periphery of the low-temperature plasma electrode.

[0014] A nitrided negative electrode sheet includes an active layer formed by a nitrided negative electrode coating slurry, wherein the nitrided negative electrode coating slurry is obtained by any of the above-mentioned silicon-carbon negative electrode nitriding methods based on a low-temperature ionization fluidization device.

[0015] Compared with the prior art, this disclosure has at least the following advantages: The aforementioned silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment, since the low-temperature plasma electrode is set in the reaction chamber, can release high-voltage corona to the ammonia-nitrogen mixture in the reaction chamber through the low-temperature plasma electrode. The ammonia-nitrogen mixture is less polluting to the environment than nitric acid, ammonia, urea, etc. The high-voltage corona first ionizes the ammonia to obtain free electrons. The free electrons can collide with nitrogen molecules to form an electron avalanche effect. In this way, the low-temperature plasma electrode can obtain a large number of nitrogen ions with lower energy consumption and easier processing. Then, the nitrogen ions enter the framework of the carbonaceous raw material through collision doping to obtain nitrided carbon. The nitrided carbon and silicon powder are composite mixed to obtain the nitrided anode coating slurry. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of a silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a cryogenic ionization fluidization device according to another embodiment of the present disclosure.

[0018] Figure label: 100. Reaction silo; 110. Discharge pipe; 200. Nitrogen injection pipeline; 210. Booster pump; 220. Ammonia storage tank; 230. Soda lime storage tank; 300. Low-temperature plasma electrode; 400. Suction purification pipeline; 410. Vacuum pump; 420. Nitrogen purifier; 500. Material enters the pipeline; 600. Microwave transmitting device; 610. Temperature detection component; 620. Pressure detection component; 700. Electromagnetic fluidization assembly; 710. Electromagnet. Detailed Implementation

[0019] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0020] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] This disclosure provides a silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device, which is executed using the low-temperature ionization fluidization device. Specifically, the aforementioned low-temperature ionization fluidization device includes a reaction chamber, a nitrogen injection pipeline, and a low-temperature plasma electrode; the reaction chamber is used to contain carbonaceous raw materials; the nitrogen injection pipeline is connected to the reaction chamber and is used to introduce an ammonia-nitrogen mixture into the reaction chamber; the low-temperature plasma electrode is disposed in the reaction chamber and is used to ionize the ammonia-nitrogen mixture.

[0023] The aforementioned silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment includes: injecting nitrogen into the reaction chamber through a nitrogen injection pipeline to mix the ammonia-nitrogen mixture with the carbonaceous raw material; ionizing the ammonia-nitrogen mixture through a low-temperature plasma electrode to obtain nitrogen ions; fluidizing and doping the nitrogen ions through the reaction chamber to allow the nitrogen ions to diffuse into the carbonaceous raw material to obtain nitrided carbon; and performing a composite mixing treatment on silicon powder and nitrided carbon to obtain a nitrided anode coating slurry.

[0024] It is understandable that, since the low-temperature plasma electrode is set inside the reaction chamber, it can release high-voltage corona to the ammonia-nitrogen mixture in the reaction chamber. Compared with nitric acid, ammonia, urea, etc., the ammonia-nitrogen mixture is less polluting to the environment. The high-voltage corona first ionizes the ammonia to obtain free electrons. These free electrons can collide with nitrogen molecules to form an electron avalanche effect. In this way, the low-temperature plasma electrode can obtain a large number of nitrogen ions with lower energy consumption and easier processing. Then, the nitrogen ions enter the framework of the carbonaceous raw material through collision doping to obtain nitrided carbonaceous material. The nitrided carbonaceous material is then combined with silicon powder to obtain the nitrided negative electrode coating slurry.

[0025] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments: Please see Figure 1and Figure 2 One embodiment of the silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device employs such a device. Specifically, the low-temperature ionization fluidization device includes a reaction chamber 100, a nitrogen injection pipeline 200, and a low-temperature plasma electrode 300. The reaction chamber 100 is used to contain carbonaceous raw materials; the nitrogen injection pipeline 200 is connected to the reaction chamber 100 and is used to introduce an ammonia-nitrogen mixture into the reaction chamber 100; the low-temperature plasma electrode 300 is disposed within the reaction chamber 100 and is used to ionize the ammonia-nitrogen mixture. The aforementioned low-temperature ionization fluidization device is applicable to the following silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device.

[0026] The above-mentioned silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment includes some or all of the following steps.

[0027] Nitrogen is injected into the reaction silo 100 through the nitrogen injection pipeline 200 to mix the ammonia-nitrogen mixture with the carbonaceous raw materials. Please see Figure 2 In this embodiment, since the nitrogen injection pipeline 200 is connected to the reaction silo 100, ammonia-nitrogen mixed gas can be introduced into the reaction silo 100 through ammonia-nitrogen mixed gas. The ammonia-nitrogen mixed gas is nitrogen gas carrying ammonia. After the ammonia-nitrogen mixed gas enters the reaction silo 100, the carbonaceous raw material can be immersed in the atmosphere of the ammonia-nitrogen mixed gas. The carbonaceous raw material can be porous carbonaceous raw material such as graphite and carbon black, so that the ammonia-nitrogen mixed gas can enter the skeleton pores of the carbonaceous raw material, thereby enabling the ammonia-nitrogen mixed gas and the carbonaceous raw material to be fully mixed.

[0028] The ammonia-nitrogen mixture is ionized using a low-temperature plasma electrode 300 to obtain nitrogen ions. Please see Figure 2 In this embodiment, after nitrogen injection into the reaction chamber 100, the ammonia-nitrogen mixture is fully mixed with the carbonaceous raw materials. Since the low-temperature plasma electrode 300 is located within the reaction chamber 100 and is a pointed electrode connected to a low-temperature plasma power supply, a high-voltage corona discharge of several kilovolts can be released into the reaction chamber 100. This high-voltage corona discharge ionizes the ammonia-nitrogen mixture. Because ammonia has a lower ionization energy, the high-voltage corona discharge first ionizes the ammonia to obtain free electrons. These free electrons, under the influence of the high-voltage corona discharge, acquire sufficient energy to collide with nitrogen molecules, thus more quickly ionizing the nitrogen to obtain nitrogen ions. The temperature of the low-temperature plasma electrode 300 is between 18°C ​​and 24°C.

[0029] Nitrogen ions are fluidized and doped through reaction silo 100 to allow nitrogen ions to diffuse into carbonaceous raw materials to obtain nitrided carbonaceous materials. Please see Figure 2 In this embodiment, after the ammonia-nitrogen mixture is ionized, a large number of nitrogen ions are formed in the reaction chamber 100. The nitrogen ions flow with the ammonia-nitrogen mixture in the reaction chamber 100, so that the nitrogen ions can enter the skeleton channels of the carbonaceous raw material with the ammonia-nitrogen mixture. The nitrogen ions collide with the carbonaceous raw material, so that the nitrogen ions can be incorporated into the skeleton of the carbonaceous raw material to modify the carbonaceous raw material into nitrided carbonaceous material.

[0030] A composite blending process was performed on silicon powder and nitrided carbonaceous material to obtain a nitrided negative electrode coating slurry.

[0031] Please see Figure 2 In this embodiment, during the fluidized bed doping treatment of nitrogen ions, the carbonaceous raw material contained in the 100-cell reaction chamber can be significantly modified into nitrided carbonaceous material. The nitrided carbonaceous material consists of nitrided powdered graphite and nitrided powdered carbon black. A composite blending treatment is performed on the silicon powder and the nitrided carbonaceous material, i.e., the silicon powder and the nitrided carbonaceous material are mixed together to prepare a nitrided negative electrode coating slurry. This nitrided negative electrode coating slurry is used to coat an electrode substrate to prepare a nitrided negative electrode sheet. The nitrogen content in the nitrided carbonaceous material is 0.2 wt% to 3 wt%.

[0032] It is understandable that, since the low-temperature plasma electrode 300 is located within the reaction chamber 100, it can release a high-voltage corona discharge into the ammonia-nitrogen mixture within the reaction chamber 100. Compared to nitric acid, ammonia, and urea, the ammonia-nitrogen mixture causes less environmental pollution. The high-voltage corona discharge first ionizes the ammonia to obtain free electrons. These free electrons collide with nitrogen molecules, creating an electron avalanche effect. Thus, the low-temperature plasma electrode 300 can obtain a large number of nitrogen ions with lower energy consumption and greater ease. These nitrogen ions then enter the framework of the carbonaceous raw material through collision doping to obtain nitrided carbonaceous material. The nitrided carbonaceous material is then combined with silicon powder to obtain a nitrided negative electrode coating slurry. The free electrons are at least ammonium ions.

[0033] In some embodiments, the following steps are included before the nitrogen injection step: Ammonia-nitrogen mixture gas is obtained by mixing nitrogen gas with ammonia water.

[0034] It is understandable that before introducing the ammonia-nitrogen mixture into the reaction silo 100 through the nitrogen injection pipeline 200, the ammonia-nitrogen mixture needs to be prepared first. This is done by mixing nitrogen with ammonia water, i.e., by passing nitrogen into ammonia water and then discharging it. Since ammonia water is volatile and produces ammonia gas, the nitrogen gas carries ammonia gas with it during the discharge process. The ammonia gas mixes with the nitrogen gas to obtain the ammonia-nitrogen mixture. Compared to directly mixing ammonia and nitrogen, the ammonia gas volatilized from the ammonia water is easier to control, thereby reducing the possibility of excessive ammonia gas escaping into the external environment and significantly improving the environmental friendliness of the ammonia-nitrogen mixture preparation process.

[0035] In this embodiment, the mass ratio of nitrogen to ammonia in the ammonia-nitrogen mixture is 7 to 9.

[0036] It is understandable that because the mass ratio of nitrogen to ammonia in an ammonia-nitrogen mixture is between 7 and 9 (the minimum ratio is 7:1 and the maximum is 9:1), the amount of ammonia in the mixture is less than the amount of nitrogen. This results in more nitrogen ions being generated through nitrogen ionization, thus reducing the amount of ammonia used and consequently reducing environmental pollution from waste gas or ammonia leaks. For example, the mass ratio of nitrogen to ammonia in an ammonia-nitrogen mixture is typically 15:2 or 17:2.

[0037] In some of these embodiments, the temperature of the ammonia water is 45°C to 65°C.

[0038] It is understandable that excessively high temperatures in ammonia solution can lead to the release of large amounts of ammonia gas, which can easily leak and pollute the environment. Conversely, excessively low temperatures can result in less ammonia gas being released, thus reducing the amount of ammonia carried by nitrogen gas. This reduces the number of free electrons generated by the high-voltage corona discharge, weakening the electron avalanche effect and ultimately affecting the nitrogen ion generation rate. Since the temperature of the ammonia solution is between 45°C and 65°C, the amount of ammonia gas released is neither excessively leaked nor insufficient to maintain the electron avalanche effect, thereby keeping the nitrogen ion generation rate stable. Specifically, the temperature of the ammonia solution can be 45°C, 55°C, or 65°C, etc., and is not limited here; those skilled in the art can choose according to their needs.

[0039] Please see Figure 2 In some embodiments, the low-temperature ionization fluidization apparatus further includes a microwave emitting device 600, which is disposed within the reaction silo 100 and is used to heat the carbonaceous raw material.

[0040] It is understood that since the microwave emitting device 600 is located within the reaction hopper 100, it can heat the carbonaceous raw material within the hopper. After heating, the carbonaceous raw material reaches a higher temperature, allowing for faster doping with subsequently generated nitrogen ions. In this embodiment, the microwave emitting device 600 is a water-cooled integrated industrial microwave emitting unit. The water-cooled integrated industrial microwave emitting unit controls the temperature through a water-cooling system, effectively reducing losses caused by high temperatures. Specifically, the water-cooled integrated industrial microwave emitting unit is positioned opposite to the low-temperature plasma electrode 300. The frequency band of the water-cooled integrated industrial microwave emitting unit is 2.45 GHz, and the selected power is adjusted according to the material characteristics and the hopper volume. For example, the power density of the water-cooled integrated industrial microwave emitting unit can be from 30 W / L to 80 W / L.

[0041] In some embodiments, the following steps are included before the nitrogen injection step: The carbonaceous raw material is heated and activated by a microwave emitting device 600 to increase its temperature.

[0042] Please see Figure 2 It is understandable that, since the microwave emitting device 600 is located inside the reaction chamber 100, before the ammonia-nitrogen mixture is introduced into the reaction chamber 100 through the nitrogen injection pipe 200, the carbonaceous raw material inside the reaction chamber 100 can be heated by the microwave emitting device 600. After being heated, the carbonaceous raw material reaches a higher temperature, thus enabling it to more quickly dope with the subsequently generated nitrogen ions. Furthermore, the increased temperature inside the reaction chamber 100 also creates a temperature field, which can increase the energy of the nitrogen ions, allowing them to collide with the carbonaceous raw material more violently.

[0043] In some embodiments, the cryogenic ionization fluidization apparatus further includes an electromagnetic fluidization component 700 disposed on the outer periphery of the reaction hopper 100, which is used to fluidize nitrogen ions.

[0044] Please see Figure 2 It is understandable that, since the electromagnetic fluidization component 700 is located on the outer periphery of the reaction chamber 100, an electromagnetic field can be formed inside the reaction chamber 100 through the electromagnetic fluidization component 700. The electromagnetic field can accelerate and increase the energy of nitrogen ions inside the reaction chamber 100. Several nitrogen ions accelerate and flow inside the reaction chamber 100 to form an ion wind. In this way, several nitrogen ions can collide more violently with carbonaceous raw materials under the drive of the magnetic field, thereby increasing the nitrogen content in the carbonaceous raw materials.

[0045] In some embodiments, the following steps are included prior to the fluidization doping treatment: Nitrogen ions are fluidized and accelerated using an electromagnetic fluidization component 700 to increase their movement speed.

[0046] Please see Figure 2 It is understandable that, since the electromagnetic fluidization component 700 is located on the outer periphery of the reaction chamber 100, it can be activated before nitrogen ions enter the skeleton channels of the carbonaceous raw material along with the ammonia-nitrogen mixture. The electromagnetic fluidization component 700 can generate an electromagnetic field within the reaction chamber 100. This electromagnetic field can accelerate and increase the energy of the large number of nitrogen ions generated by ionization within the reaction chamber 100. The large number of nitrogen ions accelerate and flow within the reaction chamber 100 to form an ion wind. In this way, the large number of nitrogen ions can collide more violently with the carbonaceous raw material under the drive of the magnetic field, thereby increasing the nitrogen content in the carbonaceous raw material.

[0047] In some embodiments, the electromagnetic fluidization assembly 700 includes a plurality of electromagnets 710, which are uniformly distributed around the outer periphery of the reaction hopper 100.

[0048] Please see Figure 2 It can be understood that, since multiple electromagnets 710 in the electromagnetic fluidization assembly 700 are arranged around the outer periphery of the reaction chamber 100, magnetic field lines can be generated by energizing the electromagnets 710. The uniform distribution of multiple electromagnets 710 enables the formation of a uniformly distributed electromagnetic field within the reaction chamber 100. By changing the direction or magnitude of the current, the magnitude and direction of the electromagnetic field can be adjusted, thereby changing the acceleration or flow direction of nitrogen ions, and flexibly adjusting the impact intensity of nitrogen ions on carbonaceous raw materials and the nitrogen content in the carbonaceous raw materials. Specifically, the reaction chamber 100 is a 316 stainless steel chamber or a plastic chamber to facilitate the passage of magnetic field lines. Furthermore, the energization of each electromagnet 710 is controlled by a PLC (Programmable Logic Controller) to cause the formed electromagnetic field region to produce alternating magnetic pole directions.

[0049] Please see Figure 2In some embodiments, both the nitrogen injection pipeline 200 and the low-temperature plasma electrode 300 are located at the bottom of the reaction chamber 100; the outlet of the nitrogen injection pipeline 200 is connected to the bottom of the reaction chamber 100 and distributed around the outer periphery of the low-temperature plasma electrode 300. It can be understood that because the nitrogen injection pipeline 200 is located at the bottom of the reaction chamber 100, and its outlet is connected to the bottom of the reaction chamber 100, and its inlet is through which ammonia-nitrogen mixture is introduced, the ammonia-nitrogen mixture can enter the bottom of the reaction chamber 100 through the nitrogen injection pipeline 200. The airflow formed by the ammonia-nitrogen mixture can drive the carbonaceous raw materials at the bottom of the reaction chamber 100 to flow, thereby causing the carbonaceous raw materials to flow and disperse, thus reducing the agglomeration of the carbonaceous raw materials. Meanwhile, the low-temperature plasma electrode 300 is positioned at the bottom of the reaction chamber 100, and the outlets of the nitrogen injection pipe 200 are distributed around the outer periphery of the low-temperature plasma electrode 300. This allows the low-temperature plasma electrode 300 to release corona discharge, which allows for sufficient contact with the ammonia-nitrogen mixture, thereby enhancing the ionization effect of the ammonia-nitrogen mixture. Furthermore, the large amount of nitrogen ions obtained from the ionization of the ammonia-nitrogen mixture can be more evenly and thoroughly mixed with the carbonaceous raw materials, thus improving the nitriding effect of the carbonaceous raw materials.

[0050] Please see Figure 2 Typically, since the carbonaceous raw materials need to be impacted by the ammonia-nitrogen mixture, and the carbonaceous raw materials in the reaction silo 100 are generally stacked from top to bottom, the nitrogen needs to be injected at a flow rate of at least 30 L / min to ensure that the ammonia-nitrogen mixture generates sufficient impact force on the carbonaceous raw materials. However, when nitrogen is injected into the ammonia water quickly, many bubbles will be generated in the ammonia water. When the bubbles burst, a large amount of water vapor will be released. A large amount of water vapor will follow the ammonia-nitrogen mixture into the reaction silo 100 and thus adhere to or fill the skeleton of the carbonaceous raw materials, thereby affecting the impact of nitrogen ions on the carbonaceous raw materials and ultimately reducing the efficiency of nitrogen embedding into the carbonaceous raw material skeleton.

[0051] To reduce the impact of water vapor on the process of nitrogen ion bombardment of carbonaceous raw materials, in some embodiments, the ammonia-nitrogen mixing treatment step specifically includes the following operations: Nitrogen gas is pressurized and accelerated to obtain a nitrogen flow rate; wherein the flow rate of the nitrogen flow rate is at least 30 L / min. The nitrogen gas stream is subjected to an ammonia-water pass-through process to obtain an ammonia-nitrogen mixed vapor; wherein the ammonia-nitrogen mixed vapor contains water vapor; The ammonia-nitrogen mixture is subjected to water separation treatment in an alkaline environment to obtain the ammonia-nitrogen mixture.

[0052] It is understandable that the nitrogen gas is pressurized and accelerated, that is, the nitrogen gas is compressed by a booster pump 210 to achieve a pressure of at least 180 kPa, thereby obtaining a nitrogen gas flow rate of at least 30 L / min when releasing nitrogen. Then, the nitrogen gas flow is subjected to an ammonia-water process, that is, the nitrogen gas flow is introduced into ammonia water through a nitrogen delivery pipe. The nitrogen gas mixes with the ammonia gas volatilized in the ammonia water and the bursting of bubbles releases a large amount of water vapor, forming an ammonia-nitrogen mixture. Finally, the ammonia-nitrogen mixture is subjected to water separation treatment in an alkaline environment, that is, the ammonia-nitrogen mixture is passed into quicklime. Quicklime absorbs the water vapor in the ammonia-nitrogen mixture without reacting with the ammonia gas. After the water in the ammonia-nitrogen mixture is absorbed, the ammonia-nitrogen mixture is obtained. The quicklime is mainly a mixture of sodium hydroxide and calcium oxide.

[0053] Please see Figure 2 Typically, to ensure that the carbonaceous raw materials in the reaction silo 100 can be fully mixed with the ammonia-nitrogen mixture, it is generally necessary to continuously inject the ammonia-nitrogen mixture into the reaction silo 100. This results in the quicklime needing to continuously absorb a large amount of water vapor. Especially during ultra-long operation periods of more than two hours, the quicklime is prone to saturation, causing some water vapor to still escape into the reaction silo 100 and affect the impact of nitrogen ions on the carbonaceous raw materials.

[0054] Please see Figure 2 To further reduce the impact of water vapor on the process of nitrogen ion bombardment of carbonaceous raw materials, in some embodiments, the heating activation treatment step specifically includes the following operations: The microwave emitting device 600 performs microwave heating on the reaction chamber 100 to increase the temperature and pressure inside the reaction chamber 100. The carbonaceous raw material is activated by constant temperature and pressure using the microwave emitting device 600, so that the temperature in the reaction chamber 100 is kept constant at 80°C and the pressure in the reaction chamber 100 is kept constant at 30 kPa.

[0055] After the ammonia-nitrogen mixture is subsequently introduced into the reaction silo 100 through the nitrogen injection pipeline 200, the water vapor in the ammonia-nitrogen mixture can evaporate and vaporize under the influence of the low-pressure temperature field, thereby reducing the impact of liquid water on the carbonaceous raw materials in the reaction silo 100. At the same time, since the temperature of the low-pressure temperature field is constant at 80℃, the reaction between the carbonaceous raw materials and water vapor is also very weak, which can reduce the loss of carbonaceous raw materials.

[0056] Please see Figure 2Specifically, in some embodiments, the microwave emitting device 600 has a temperature detection component 610 and a pressure detection component 620, both of which are installed on the wall of the reaction silo 100. The temperature detection component 610 is used to detect the temperature inside the reaction silo 100, and the pressure detection component 620 is used to detect the pressure inside the reaction silo 100. The temperature detection component 610 and the pressure detection component 620 are electrically connected to the power regulation system of the microwave emitting device 600.

[0057] The steps of the isothermal pressure activation operation specifically include: The current temperature parameters inside the reaction silo 100 are obtained by the temperature detection component 610; The current temperature parameter and the constant temperature parameter are subjected to temperature difference processing to obtain the temperature difference component; wherein, the constant temperature parameter is 80℃, and the temperature difference processing can be used to calculate the absolute temperature difference between the current temperature parameter and the constant temperature parameter; According to the temperature difference component, a microwave power increase / decrease signal is sent to the power regulation system to make the average temperature in the reaction silo 100 80°C. The pressure detection component 620 acquires the current pressure parameters within the reaction silo 100. The current pressure parameter and the constant pressure parameter are subjected to pressure differential processing to obtain the pressure differential component; wherein, the constant pressure parameter is 30 kPa, and the pressure differential processing can be used to calculate the absolute pressure difference between the current pressure parameter and the constant pressure parameter; According to the temperature difference component, a microwave power increase / decrease signal is sent to the power regulation system to make the average pressure in the reaction silo 100 30kPa.

[0058] It is understood that the temperature detection component 610 can acquire the temperature inside the reaction chamber 100 in real time, thereby obtaining the current temperature parameter inside the reaction chamber 100. The constant temperature parameter is the preset constant temperature inside the reaction chamber 100 in the activated state. By adjusting the pressure difference component between the current temperature parameter and the constant temperature parameter, the difference between the current temperature parameter and the constant temperature parameter can be obtained, that is, the temperature difference component can be obtained. The temperature difference component can be used to determine whether the temperature inside the reaction chamber 100 is too high or too low. Therefore, the microwave power increase / decrease signal can be sent to the power adjustment system according to the temperature difference component. The power adjustment system can acquire the microwave power increase / decrease signal and thus increase or decrease the current power of the microwave transmitter 600 in real time so that the current temperature inside the reaction chamber 100 is close to 80°C. Simultaneously, the pressure detection component 620 can acquire the pressure inside the reaction chamber 100 in real time, thereby obtaining the current pressure parameter inside the reaction chamber 100. The constant pressure parameter is the preset constant pressure inside the reaction chamber 100 in the activated state. By adjusting the pressure difference component between the current pressure parameter and the constant pressure parameter, the difference between the current pressure parameter and the constant pressure parameter can be obtained, that is, the pressure difference component is obtained. Through the pressure difference component, it can be determined whether the pressure inside the reaction chamber 100 is too high or too low. Therefore, a microwave power increase / decrease signal can be sent to the power adjustment system according to the pressure difference component. The power adjustment system acquires the microwave power increase / decrease signal and can increase or decrease the current power of the microwave transmitting device 600 in real time so that the current pressure inside the reaction chamber 100 is close to 30 kPa.

[0059] Furthermore, the step of sending a microwave power increase / decrease signal to the power regulation system based on the temperature difference component specifically includes the following steps: The temperature difference component is compared with the preset temperature difference; wherein the preset temperature difference is 1℃. When the temperature difference component is greater than the preset temperature difference, a microwave power reduction signal is sent to the power regulation system to reduce the current temperature in the reaction silo 100. When the temperature difference component is less than the preset temperature difference, a microwave power increase signal is sent to the power regulation system to raise the current temperature inside the reaction silo 100.

[0060] Furthermore, the step of sending a microwave power increase / decrease signal to the power regulation system based on the voltage difference component specifically includes the following steps: The differential pressure component is compared with a preset differential pressure value; wherein the preset differential pressure value is 1 kPa. When the differential pressure component is greater than the preset differential pressure, a microwave power reduction signal is sent to the power regulation system to reduce the current pressure in the reaction silo 100; When the differential pressure component is less than the preset differential pressure, a microwave power increase signal is sent to the power regulation system to increase the current pressure in the reaction silo 100.

[0061] Typically, in order for the ammonia-nitrogen mixture to impinge on the flow of carbonaceous raw materials, the ammonia-nitrogen mixture needs to be continuously and in large quantities introduced into the reaction silo 100. This can easily lead to an excess of ammonia-nitrogen mixture in the reaction silo 100, and the excess ammonia-nitrogen mixture in the reaction silo 100 can also easily escape during the discharge process of the reaction silo 100, resulting in waste or pollution.

[0062] Please see Figure 2 To reduce air pollution and waste caused by the ammonia-nitrogen mixture, in some embodiments, the low-temperature ionization fluidization device further includes a suction purification pipeline 400 and a material inlet pipeline 500. The outlet of the material inlet pipeline 500 and the suction port of the suction purification pipeline 400 are both connected to the top of the reaction silo 100. The material inlet pipeline 500 is used to introduce carbonaceous raw materials or air into the reaction silo 100. The nitrogen outlet of the suction purification pipeline 400 is connected to the air inlet of the nitrogen injection pipeline 200. The air inlet of the nitrogen injection pipeline 200 is connected to a nitrogen source. Between the fluidized doping treatment step and the composite doping treatment step, the following step is also included: The exhaust gas inside the reaction chamber 100 is extracted through the suction purification pipeline 400 to make the reaction chamber 100 a vacuum state. Please see Figure 2 In this embodiment, after obtaining nitrided carbonaceous material through fluidized bed doping treatment, the waste gas in the reaction silo 100 is treated by suction purification pipeline 400. This allows the excess ammonia-nitrogen mixture in the reaction silo 100 to be purified into nitrogen gas through suction purification pipeline 400, and the nitrogen gas is then drawn into the inlet of nitrogen injection pipeline 200. This allows the nitrogen gas in the ammonia-nitrogen mixture to be recovered and reused through nitrogen injection pipeline 200, thereby significantly reducing the waste or pollution of ammonia-nitrogen mixture.

[0063] The material inlet pipeline 500 is used to replenish and stabilize the pressure inside the reaction silo 100 so as to balance the air pressure inside and outside the reaction silo 100. Please see Figure 2In this embodiment, after the exhaust gas in the reaction silo 100 is extracted and treated by the suction purification pipeline 400, the gas pressure in the reaction silo 100 will be lower than the atmospheric pressure. At this time, the nitrided carbonaceous material in the reaction silo 100 will not be able to be discharged to the silicon powder storage silo through the discharge pipe 110 of the reaction silo 100. The gas is replenished and the pressure is stabilized by the material inlet pipeline 500, that is, air is introduced into the reaction silo 100 through the material inlet pipeline 500 to balance the gas pressure inside and outside the reaction silo 100, so that the discharge pipe 110 of the reaction silo 100 can discharge the material smoothly.

[0064] The finished product is discharged through the discharge pipe 110 of the reaction silo 100 to remove the nitrided carbonaceous material.

[0065] Please see Figure 2 In this embodiment, the discharge pipe 110 of the reaction silo 100 is connected to a silicon powder storage silo, which contains silicon powder. After fluidized bed doping treatment, carbonaceous raw materials are obtained in the reaction silo 100. The discharge pipe 110 of the reaction silo 100 is opened, allowing the carbonaceous raw materials to enter the silicon powder storage silo. The silicon powder and nitrided carbonaceous materials are mixed together to prepare a nitrided negative electrode coating slurry. This nitrided negative electrode coating slurry is used to coat an electrode substrate to prepare a nitrided negative electrode sheet. Subsequently, the material inlet pipe 500 can continue to input new carbonaceous raw materials into the reaction silo 100, thereby nitriding the new carbonaceous raw materials and ultimately achieving continuous production of the nitrided negative electrode coating slurry. In this process, carbonaceous raw materials are fed into the reaction silo 100 via vacuum feeding. Specifically, the vacuum inside the reaction silo 100 is evacuated to a preset level that allows the material inlet pipe 500 to draw the external carbonaceous raw materials into the reaction silo 100.

[0066] Please see Figure 2 Furthermore, the suction purification pipeline 400 consists of a vacuum pump 410 and a nitrogen purifier 420 connected in sequence. The reaction chamber 100 is connected to the suction port of the vacuum pump 410, and the exhaust port of the nitrogen purifier 420 is connected to the inlet of the nitrogen injection pipeline 200. It can be understood that the ammonia-nitrogen mixture in the reaction chamber 100 can first be drawn into the vacuum pump 410, and then the vacuum pump 410 discharges the ammonia-nitrogen mixture to the conventional nitrogen purifier 420. The nitrogen purifier 420 purifies the nitrogen in the ammonia-nitrogen mixture and discharges the nitrogen to the inlet of the nitrogen injection pipeline 200, thereby achieving the recovery and reuse of waste gas in the reaction chamber 100.

[0067] Please see Figure 2Furthermore, the nitrogen injection pipeline 200 comprises a booster pump 210, an ammonia water storage tank 220, and a quicklime storage tank 230 connected in sequence. The inlet of the booster pump 210 is connected to the nitrogen outlet of the suction purification pipeline 400 and the nitrogen source, respectively. The exhaust port of the quicklime storage tank 230 is the outlet of the nitrogen injection pipeline 200. It can be understood that the booster pump 210 compresses the nitrogen gas discharged from the suction purification pipeline 400 and the nitrogen gas released from the nitrogen source, increasing the flow rate of the nitrogen gas to form a nitrogen gas flow. The nitrogen gas flow carries away the ammonia gas volatilized from the ammonia water in the ammonia water storage tank 220. The nitrogen gas and ammonia gas are dried and mixed in the quicklime storage tank 230 to obtain an ammonia-nitrogen mixture.

[0068] Please see Figure 1 and Figure 2 This disclosure also provides a nitrided negative electrode sheet, including an active layer formed by a nitrided negative electrode coating slurry. The nitrided negative electrode coating slurry is obtained using the silicon-carbon negative electrode nitriding method based on a low-temperature ionization fluidization device according to any of the above embodiments. It can be understood that by applying the silicon-carbon negative electrode nitriding method based on a low-temperature ionization fluidization device of this disclosure to the preparation process of the nitrided negative electrode coating slurry, since the low-temperature plasma electrode 300 is set in the reaction chamber 100, a high-voltage corona discharge can be released to the ammonia-nitrogen mixture in the reaction chamber 100 through the low-temperature plasma electrode 300. The ammonia-nitrogen mixture has less environmental pollution than nitric acid, ammonia, urea, etc. The high-voltage corona discharge first ionizes the ammonia to obtain free electrons. The free electrons can collide with nitrogen molecules to form an electron avalanche effect. In this way, the low-temperature plasma electrode 300 can obtain a large number of nitrogen ions with lower energy consumption and easier processing. Then, the nitrogen ions enter the framework of the carbonaceous raw material through collision doping to obtain nitrided carbonaceous material. The nitrided carbonaceous material and silicon powder are composite mixed to obtain the nitrided negative electrode coating slurry. Nitrogen ion doping into the framework of carbonaceous raw materials effectively improves the hydrophilicity of carbonaceous raw materials, increases their adsorption capacity and catalytic active sites. As the hydrophilicity of carbonaceous raw materials increases, they are easier to mix with silicon powder and water to prepare slurry.

[0069] Compared with the prior art, this disclosure has at least the following advantages: The aforementioned silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment, since the low-temperature plasma electrode 300 is set inside the reaction chamber 100, can release high-voltage corona to the ammonia-nitrogen mixture in the reaction chamber 100 through the low-temperature plasma electrode 300. The ammonia-nitrogen mixture is less polluting to the environment than nitric acid, ammonia, urea, etc. The high-voltage corona first ionizes the ammonia to obtain free electrons. The free electrons can collide with nitrogen molecules to form an electron avalanche effect. In this way, the low-temperature plasma electrode 300 can obtain a large number of nitrogen ions with lower energy consumption and easier processing. Then, the nitrogen ions enter the framework of the carbonaceous raw material through collision doping to obtain nitrided carbonaceous material. The nitrided carbonaceous material and silicon powder are composite mixed to obtain nitrided anode coating slurry.

[0070] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for nitriding a silicon-carbon anode based on a low-temperature ionization fluidization device, characterized in that, The process is performed using a cryogenic ionization fluidization device, which includes: A reaction silo, which is used to contain carbonaceous raw materials; A nitrogen injection pipeline, wherein the nitrogen injection pipeline is connected to the reaction silo, and the nitrogen injection pipeline is used to introduce an ammonia-nitrogen mixture into the reaction silo; and A low-temperature plasma electrode is disposed in the reaction chamber and is used to ionize the ammonia-nitrogen mixture. The silicon-carbon anode nitriding method based on low-temperature ionization fluidization equipment includes the following steps: Nitrogen is injected into the reaction silo through the nitrogen injection pipeline to mix the ammonia-nitrogen mixture with the carbonaceous raw material. The ammonia-nitrogen mixture is ionized using the low-temperature plasma electrode to obtain nitrogen ions. The nitrogen ions are fluidized and doped through the reaction silo to allow the nitrogen ions to diffuse into the carbonaceous raw material to obtain nitrided carbonaceous material. The silicon powder and the nitrided carbonaceous material are subjected to a composite mixing process to obtain a nitrided negative electrode coating slurry.

2. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 1, characterized in that, Before the nitrogen injection treatment step, the following steps are also included: The ammonia-nitrogen mixture is obtained by mixing nitrogen gas with ammonia water.

3. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 2, characterized in that, The temperature of the ammonia water is between 45°C and 65°C.

4. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 1, characterized in that, The low-temperature ionization fluidization equipment also includes a microwave emitting device, which is located inside the reaction silo and is used to heat the carbonaceous raw material.

5. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 4, characterized in that, Before the nitrogen injection treatment step, the following steps are also included: The carbonaceous raw material is heated and activated by the microwave emitting device to increase its temperature.

6. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 1, characterized in that, The low-temperature ionization fluidization device also includes an electromagnetic fluidization component, which is disposed on the outer periphery of the reaction hopper and is used to fluidize the nitrogen ions.

7. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 6, characterized in that, Prior to the fluidized doping treatment step, the following steps are also included: The nitrogen ions are fluidized and accelerated by the electromagnetic fluidization component to increase their movement speed.

8. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 6, characterized in that, The electromagnetic fluidization assembly includes a plurality of electromagnets, which are spaced apart around the outer periphery of the reaction hopper.

9. The silicon-carbon anode nitriding method based on a low-temperature ionization fluidization device according to claim 1, characterized in that, Both the nitrogen injection pipeline and the low-temperature plasma electrode are located at the bottom of the reaction chamber; the outlet of the nitrogen injection pipeline is connected to the bottom of the reaction chamber and distributed around the outer periphery of the low-temperature plasma electrode.

10. A nitrided negative electrode, characterized in that, The active layer includes a nitrided negative electrode coating slurry, wherein the nitrided negative electrode coating slurry is obtained by the silicon-carbon negative electrode nitriding method based on a low-temperature ionization fluidization device as described in any one of claims 1 to 9.

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