A fast-charging negative electrode material production process and device

Abstract

A fast-charging negative electrode material production process and device, including a bucket elevator, a silo, a melting tank, a pressure tower, a distillation tower, a crusher, a screening machine, and a high-temperature carbonization furnace. The bucket elevator is connected to the silo, and the silo feeds the melting tank through a screw feeder. The melting tank is connected to the pressure tower, and the light phase extraction port of the pressure tower is connected to the distillation tower. The coke outlet of the pressure tower feeds the crusher, the crusher feeds the screening machine, and the screening machine feeds the high-temperature carbonization furnace. In the present invention, different asphalt raw materials are coked in a pressure tower after rough crushing or direct melting, and then crushed and screened after coking, and then carbonized in a high-temperature carbonization furnace to obtain a negative electrode material with excellent electrochemical performance and stable material structure. The high-capacity fast-charging negative electrode material prepared by the present invention has high battery safety performance, high capacity, good rate performance, excellent cycle performance, and outstanding anti-attenuation ability. It is an excellent raw material for lithium-ion, sodium-ion batteries, and fast-charging battery equipment.

Description

Technical Field

[0001] The present invention belongs to the field of negative electrode materials, and in particular relates to a production process and device for fast-charging negative electrode materials. Background Art

[0002] With the application of information technology equipment in daily life, humans have put forward higher requirements for the performance of lithium-ion batteries, and the development of fast-charging negative electrode materials has become one of the important research directions for the development of lithium batteries. At the same time, lithium-ion batteries dominate rechargeable batteries, but due to the shortcomings of limited lithium resources and high costs, research on sodium-ion batteries with abundant resources and lower costs is also an important research direction for energy storage technology.

[0003] Based on the stable structure of fast-charging negative electrode materials, they have excellent rate characteristics, long cycle life, high reversible specific capacity, low production cost, good cycle stability, high lithium insertion potential and high safety performance. At the same time, they have a high Li+ diffusion coefficient and a wide insertion potential range, which facilitates the rapid insertion of Li+ without the precipitation of metallic lithium, and is more suitable for charging and discharging at high current density. Fast-charging negative electrode materials can also be used in sodium-ion batteries. Sodium-ion batteries are considered by scientists to be one of the ideal choices to replace lithium-ion batteries as the next generation of power vehicles and supporting power sources for large power stations. Therefore, fast-charging negative electrode materials have potential application value in both lithium-ion and sodium-ion battery negative electrodes.

[0004] Patent document CN106099109A uses medium-temperature asphalt as raw material, terephthalic acid as a cross-linking agent, and benzenesulfonic acid as a catalyst to cross-link and modify the asphalt, and then adds sodium chloride templates and other materials for carbonization to obtain asphalt-based hard carbon nanosheets. The reversible capacity of the hard carbon negative electrode material prepared by this process is only 270mAh / g. The process steps are cumbersome, and a variety of organic additives are added during asphalt modification, which will bring corresponding problems to the environment and operating costs, and it is difficult to industrialize. Patent document CN103011127A crushes and solidifies asphalt with a softening point below 280°C and carbonizes it to produce hard carbon. The specific surface area of ​​the resulting negative electrode material is too high, which increases the irreversible capacity of the first charge and discharge, and reduces the charge and discharge efficiency of the electrode material. Summary of the invention

[0005] The present invention provides a fast-charging negative electrode material production process and device, wherein different asphalt raw materials are coarsely crushed or directly melted and then put into a pressure tower for coking, and after the coke is taken out, they are crushed and screened and then put into a high-temperature carbonization furnace for carbonization to obtain a negative electrode material with excellent electrochemical performance and stable material structure. The high-capacity fast-charging negative electrode material prepared by the present invention has high battery safety performance, high capacity, good rate performance, excellent cycle performance, outstanding anti-attenuation ability, and the process method is simple and feasible and can be produced continuously, and is an excellent raw material for lithium-ion, sodium-ion batteries, and fast-charging battery equipment.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A fast-charging negative electrode material production process, wherein different asphalt raw materials are coarsely crushed or directly melted and then put into a pressure tower for coking, and after the coke is taken out, the raw materials are crushed and screened and then put into a high-temperature carbonization furnace for carbonization to obtain a fast-charging negative electrode material; the specific process steps include:

[0008] 1) Raw material pretreatment: Soft asphalt is pumped out from the raw material tank by a pump and directly enters the heating tank for melting; hard asphalt is crushed by a coarse crusher and enters the silo through a bucket elevator. The screw feeder drives the hard asphalt material into the heating tank for melting;

[0009] 2) Coking: The raw asphalt is melted and pumped into a pressure tower for coking;

[0010] 3) Recovery of distillate oil from the distillation tower: The distillate oil from the pressure tower enters the bottom of the distillation tower and is distilled to obtain light phase oil and heavy oil. The light phase oil is sold, and part of the heavy oil fraction is pumped into the pressure tower as a coking aid, and the other part is pumped into the raw material tank area as a polymer asphalt raw material;

[0011] 4) Crushing and screening: After the coke is formed in the pressure tower, the raw coke enters the crusher for crushing and the screening machine for screening and grading;

[0012] 5) Carbonization: The powder obtained after screening and grading enters a high-temperature carbonization furnace for carbonization.

[0013] 6) Finished product: After carbonization, the material passes through the belt corridor into the finished product warehouse for packaging.

[0014] The hard asphalt is asphalt powder with a coarse crushing particle size of less than 1 cm.

[0015] In the above step 1), the melting temperature of the hot pot is 100-200° C., the heating rate is 1-15° C. / min, and the constant temperature time is 0.5-5 h.

[0016] In the above step 2), the pressure of the pressure tower is 0.1-3Mpa, the coking temperature is 450°C-580°C, the heating rate is 1-30°C / min, and the constant temperature time is 1-8h.

[0017] The microstructure of the raw coke in the pressure tower coking in the above step 2) is a flake structure with a length of 3 to 100 μm and a width of 3 to 100 μm.

[0018] The crushing and screening particle size D50 in the above step 4) is 10 to 25 μm.

[0019] The carbonization temperature in the above step 5) is 1000-1800° C., the heating rate is 1-30° C. / min, and the constant temperature time is 1-8 hours.

[0020] A device used in a production process of fast-charging negative electrode materials includes a bucket elevator, a silo, a melting tank, a pressure tower, a distillation tower, a crusher, a screening machine, and a high-temperature carbonization furnace. The bucket elevator is connected to the silo, and the silo feeds the melting tank through a screw feeder. The melting tank is connected to the pressure tower, and the light phase extraction port of the pressure tower is connected to the distillation tower. The coke outlet of the pressure tower feeds the crusher, the crusher feeds the screening machine, and the screening machine feeds the high-temperature carbonization furnace.

[0021] There are two pressurizing towers, which are used alternately for coking and coking to achieve continuous production.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The high-capacity fast-charging negative electrode material prepared by the present invention obtains a special microscopic sheet structure by controlling the pre-carbonization process parameters, and is charged and discharged under high power density conditions. The material structure is stable and is an excellent raw material for fast-charging battery equipment;

[0024] 2) The negative electrode material prepared by the present invention has excellent electrochemical properties and can be widely used in lithium ion and sodium ion battery devices;

[0025] 3) The negative electrode material prepared by the present invention has high battery safety performance, high capacity, good rate performance, excellent cycle performance, and outstanding anti-attenuation ability;

[0026] 4) The pressurized tower used in the present invention is a continuous production device, which realizes continuous production and ensures maximum production capacity;

[0027] 5) The distillation tower used in the present invention recovers the distilled fraction oil, distills the light phase oil for sale, and the heavy phase oil can be recovered to make special asphalt raw material.

[0028] 6) The negative electrode material prepared by the production process of the present invention has been tested and has excellent electrical properties, a high retention rate for multiple charge and discharge cycles, and is suitable for high-rate charge and discharge. It is a high-quality energy storage material. The production process achieves continuous production and has considerable economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a process flow chart of the present invention.

[0030] In the figure: 1-soft asphalt raw material; 2-asphalt melting tank; 3-silo; 4-bucket elevator; 5-hard asphalt raw material; 6-1# pressure tower; 7-2# pressure tower; 8-distillation tower; 9-light oil tank; 10-heavy oil tank; 11-crusher; 12-screening machine; 13-high temperature carbonization furnace; 14-finished product warehouse. DETAILED DESCRIPTION

[0031] The following further describes the embodiments of the present invention in conjunction with specific examples:

[0032] like Figure 1 As shown, a fast-charging negative electrode material production process is to coke different asphalt raw materials into a pressure tower after coking or direct melting, crush and screen them after coking, and then carbonize them into a high-temperature carbonization furnace to obtain fast-charging negative electrode materials; the specific process steps include:

[0033] 1) Raw material pretreatment: Soft asphalt is pumped out from the raw material tank by a pump and directly enters the heating tank 2 for melting; hard asphalt is crushed by the coarse crusher and enters the silo 3 through the bucket elevator 4. The screw feeder drives the hard asphalt material into the heating tank 3 for melting;

[0034] 2) Coking: The raw asphalt is melted and pumped into a pressure tower for coking;

[0035] 3) Recovery of distillate oil from the distillation tower: The distillate oil from the pressure tower coking enters the bottom of the distillation tower and is distilled to obtain light phase oil and heavy oil. The light phase oil is sold; a part of the heavy phase oil is pumped into the pressure tower as a coking aid, and the other part is pumped into the raw material tank area as a raw material for polymer asphalt.

[0036] 4) Crushing and screening: After the coke is formed in the pressure tower, the raw coke enters the crusher for crushing and the screening machine for screening and grading;

[0037] 5) Carbonization: The powder obtained after screening and grading enters a high-temperature carbonization furnace for carbonization.

[0038] 6) Finished product: The carbonized material passes through the belt corridor into the finished product warehouse 14 for packaging.

[0039] The soft asphalt is a mixture of one or more types of coal-based soft asphalt or petroleum-based soft asphalt; the hard asphalt is a mixture of one or more types of coal-based asphalt or petroleum-based asphalt.

[0040] The hard asphalt is asphalt powder with a coarse crushing particle size of less than 1 cm.

[0041] In the above step 1), the melting temperature of the hot pot is 100-200° C., the heating rate is 1-15° C. / min, and the constant temperature time is 0.5-5 h.

[0042] In the above step 2), the pressure of the pressure tower is 0.1-3Mpa, the coking temperature is 450°C-580°C, the heating rate is 1-30°C / min, and the constant temperature time is 1-8h.

[0043] The microstructure of the raw coke in the pressure tower coking in the above step 2) is a flake structure with a length of 3 to 100 μm and a width of 3 to 100 μm.

[0044] The crushing and screening particle size D50 in the above step 4) is 10 to 25 μm.

[0045] The carbonization temperature in the above step 5) is 1000-1800° C., the heating rate is 1-30° C. / min, and the constant temperature time is 1-8 hours.

[0046] A device used in a production process of fast-charging negative electrode materials includes a bucket elevator 5, a silo 3, a melting tank 2, a pressure tower 8, a distillation tower 9, a crusher 11, a screener 12, and a high-temperature carbonization furnace 13. The bucket elevator 5 is connected to the silo 3, and the silo 3 feeds the melting tank 2 through a screw feeder. The melting tank 2 is connected to the pressure tower, and the light phase extraction port of the pressure tower is connected to the distillation tower 8. The coke outlet of the pressure tower feeds the crusher 11, the crusher 11 feeds the screener 12, and the screener 12 feeds the high-temperature carbonization furnace 13.

[0047] The soft asphalt raw material 1 directly enters the melting tank 2, and the hard asphalt is roughly crushed and then enters the silo 3 through a bucket lift. The bottom of the silo 3 is connected to a screw feeder and enters the melting tank 2; the light phase outlet of the pressure tower is connected to the inlet of the distillation tower 8; the melting tank 2 is provided with a heater and a stirrer.

[0048] There are two pressure towers, 1# pressure tower 6 and 2# pressure tower 7; the coking and coking are used alternately to realize continuous production.

[0049] Example:

[0050] The production process of a fast-charging negative electrode material of the present invention was adopted, and the main indicators of 5 batches were recorded as shown in Table 1;

[0051] Table 1 Raw materials and main indicators of each batch

[0052]

[0053]

[0054] The process parameters of the pressure tower in the embodiment are shown in Table 2:

[0055] Table 2 Main parameters of delayed coking process

[0056]

[0057] The negative electrode material indicators of each batch in the embodiment are shown in Table 3

[0058] Table 3 Main indicators of negative electrode materials

[0059] batch D50(μm) <![CDATA[d 002 (nm)]]> Charge capacity (mAh / g) efficiency(%) 1 12.25 3.6950 391 96.12 2 22.13 3.7476 396 85.22 3 25.96 3.6514 383 93.15 4 17.42 3.6641 402 90.37 5 20.53 3.6889 415 89.76

[0060] The above embodiments are implemented on the premise of the technical solution of the present invention, which are only embodiments of the tripod of the present invention, and are not limitations on other forms of the present invention. Any technician familiar with this profession, any simple modification, equivalent transformation and modification made according to the technical essence and concept of the present invention to deviate from the content of the technical solution of the present invention, still falls within the scope of protection of the present invention.

Claims

1. A fast-charging negative electrode material production process, characterized in that: Different asphalt raw materials are coarsely crushed or directly melted and then put into a pressure tower for coking. After the coke is taken out, it is crushed and screened and then put into a high-temperature carbonization furnace for carbonization to obtain fast-charging negative electrode materials. The specific process steps include: 1) Raw material pretreatment: Soft asphalt is pumped out from the raw material tank and directly melted in the heating tank; After the hard asphalt is crushed by the coarse crusher, it enters the silo through the bucket elevator, and the screw feeder drives the hard asphalt material into the heating tank for melting; 2) Coking: The raw asphalt is melted and pumped into a pressure tower for coking; The pressure of the pressure tower is 0.1-3Mpa, the coking temperature is 450℃-580℃, the heating rate is 1-30℃ / min, and the constant temperature time is 1-8h; The microstructure of the raw coke produced in the pressurized tower is a flake structure with a length of 3 to 100 μm and a width of 3 to 100 μm. 3) Recovery of distillate oil from the distillation tower: The distillate oil from the pressure tower coking enters the bottom of the distillation tower, and is distilled to obtain light phase oil and heavy oil. Part of the heavy oil fraction is pumped into the pressure tower as a coking aid, and the other part is pumped into the raw material tank area as a polymer asphalt raw material; 4) Crushing and screening: After the coke is formed in the pressure tower, the raw coke enters the crusher for crushing and the screening machine for screening and grading; The crushing and screening particle size D50 is 10-25 μm; 5) Carbonization: The powder obtained after screening and grading enters a high-temperature carbonization furnace for carbonization.

2. According to claim 1, a fast-charging negative electrode material production process is characterized in that: The hard asphalt is asphalt powder with a coarse crushing particle size of less than 1 cm.

3. According to claim 1, a fast-charging negative electrode material production process is characterized in that: In the above step 1), the melting temperature of the heating tank is 100-200°C, the heating rate is 1-15°C / min, and the constant temperature time is 0.5-5h.

4. According to claim 1, a fast-charging negative electrode material production process is characterized in that: In the above step 5), the carbonization temperature is 1000-1800°C, the heating rate is 1-30°C / min, and the constant temperature time is 1-8h.

5. According to claim 1, a fast-charging negative electrode material production process is characterized in that: There are two pressure towers, which are used alternately for coking and decoking.

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