A thick electrode having a directional pore structure

Abstract

The present application relates to a kind of thick electrode with directional pore structure.The thick electrode is precisely regulated by adding inorganic foaming agent to construct the directional pore structure of electrode sheet, then using a kind of carbon particles derived from carbon smoke in automobile exhaust as conductive agent, so as to enhance the lithium activity and conductivity of thick electrode, and improve the stability of pore structure, finally a kind of thick electrode with directional pore structure can be prepared.The prepared thick electrode has the characteristics of uniform pore and mechanical stability, and makes up the short board of traditional thick electrode with larger internal resistance and poor dynamic performance.The present application is suitable for ternary, lithium cobaltate, lithium manganate and other positive electrode materials, and the thick electrode manufactured is used in lithium ion battery, which realizes higher energy density and rate performance, and more excellent cycle life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium batteries, and particularly relates to a thick electrode with a directional pore structure. BACKGROUND

[0002] In recent years, due to the change of social production and life style, the disadvantages of traditional fossil energy are increasingly magnified, and new energy continuously occupies more market share. Benefiting from the expansion of the current portable electronic, power grid energy storage and electric vehicle market, especially the lithium ion battery equipment representing chemical energy storage, an unprecedented development and opportunity is ushered in, and the demand for lithium ion batteries with high energy density and cycle stability is increasingly urgent. After decades of development, the lithium ion battery prepared based on the positive electrode of layered metal oxide and the graphite negative electrode has approached the limit of its single theoretical energy density (about 250 Wh / kg), and according to the requirements, to achieve a single energy density of 350 Wh / kg, more advanced battery manufacturing technology must be developed.

[0003] Generally speaking, there are two major directions to achieve higher energy density: (1) developing battery materials with higher specific capacity and matching the corresponding battery system; (2) more advanced battery structure design. Under the premise of basically not changing the properties and system characteristics of the battery material, the design and optimization of the battery structure can provide a more practical and effective method for the improvement of the energy density of the battery. Since the battery capacity is fundamentally derived from the positive and negative active materials of the battery, the core principle of the battery structure design is to reduce the proportion of non-active materials, and the common strategies include: (1) improving the sealing strength of the battery to improve the filling density; (2) improving the dynamic ability of the electrolyte; (3) thick electrode preparation. The first two are more difficult to achieve, because the cost and overall safety need to be accurately evaluated. In summary, the strategy of preparing thick electrodes for lithium ion batteries is more simple and efficient.

[0004] The design of thick electrode can greatly increase the load of active material, thereby improving the energy density of the battery. For example, if the current coating thickness of 100-200 mu m is increased to 300-500 mu m, the proportion of active material will be increased by more than 30%, thereby improving the energy density. However, in the electrode structure, merely increasing the coating thickness of the electrode will increase the transmission distance of electrons and ions, the kinetic performance will be poor, the resistance will increase during the charging and discharging process, and the polarization will be serious, which will greatly affect the rate performance of the battery and hinder the improvement of the energy density. In addition, the thick electrode will also have phenomena such as delamination and fracture during the drying process due to its thick characteristics, so it is not advisable to prepare a thick electrode by merely increasing the coating thickness, and a new method for preparing a thick electrode must be developed. In recent years, strategies for optimizing the design of thick electrodes have emerged, mainly including: (1) slurry layering coating technology; (2) 3D printing pore forming technology; (3) sacrificial template pore forming technology; (4) percolation network construction technology, etc., but these emerging technologies all face the same bottleneck, that is, they cannot realize large-scale and low-cost production.

[0005] Therefore, it is particularly important to find a simple, scalable and low-cost strategy for preparing a thick electrode. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art and provide a thick electrode with a directional pore structure, which can be applied to ternary, lithium cobaltate, lithium manganate and other positive electrode materials. The lithium ion battery prepared therefrom has high energy density and high rate performance.

[0007] To achieve the above-mentioned purposes of the application, the technical solutions adopted by the present application are as follows:

[0008] A thick electrode positive electrode of a lithium battery with a directional pore structure, wherein the thick electrode positive electrode material is one or more of nickel-cobalt-manganese ternary material, lithium cobaltate material and lithium manganate material, the thick electrode conductive agent is small particle super conductive carbon black (SuperP) and carbon soot derived carbon particles, and the thick electrode adopts an inorganic foaming agent to form pores.

[0009] The present application provides a directional pore structure constructed by adding an inorganic foaming agent, and a carbon soot derived carbon particle conductive agent, thereby enhancing the lithium affinity activity and conductivity of the thick electrode, and improving the stability of the pore structure.

[0010] By adding an appropriate amount of one or more inorganic foaming agents in the material homogenization stage, during the drying process of the pole piece, the foaming agent is heated to produce bubbles that escape along the direction perpendicular to the pole piece. The rising process of numerous bubbles in the slurry with high viscosity will leave directional channels perpendicular to the pole piece, thereby preparing a thick electrode with a directional channel structure. By adjusting the type and amount of inorganic foaming agent, drying temperature and time, and coating thickness, the parameters of the directional channels can be accurately designed to ensure the uniformity of the channels in the entire pole piece. During charging and discharging, unlike traditional charge homogeneous transport, due to this special directional channel structure, the transport barrier of lithium ions in the matrix will be greatly reduced, and the lithium ions will preferentially enter the channels from the matrix, then transfer and diffuse, thereby relieving the concentration gradient of lithium ions in the pole piece matrix and reducing the overpotential polarization behavior caused by the over-thickness of the pole piece during charging and discharging.

[0011] However, thickening the electrode will still increase the internal resistance of the pole piece, although the channels on the pole piece will alleviate some battery polarization behavior, but the charge transfer polarization phenomenon in the matrix still exists. Based on this, we prepared carbon soot derived carbon particle conductive agent to enhance the lithium affinity activity and conductivity of thick pole pieces and improve the stability of the channel structure. We used carbon soot particles in automobile exhaust as the carbon source, which not only alleviates environmental problems, but also is a new idea and method for converting non-renewable energy waste into sustainable clean energy. We used the metal ion complexing ability of phytic acid to complex metal ions in situ on the purified carbon particles, and the reaction proceeded spontaneously. Then heat treatment was carried out to remove nitrogen and sulfur impurities in the carbon soot particles again. The phytic acid layer complexed with metal ions carbonizes to form carbon six-membered rings, some of which are doped with phosphorus. High temperature causes the M-O bond to break, most of which are converted into metal elements, and a part is converted into metal phosphides. After the crushing process, metal-loaded phosphorus-doped carbon particles are prepared. The particle size D50 of the carbon particles after heat treatment is between 50-100 nm, which is a mesoporous material with high specific surface area, and due to the complexation of phytic acid, it has a certain network continuity. The presence of phosphorus-doped carbon rings and elemental metals makes the material have good lithium affinity, and the thick electrode prepared using this conductive agent has better electrical activity and conductivity in the battery system, and the continuous conductive agent also helps to stabilize the structure of the pole piece.

[0012] It can be seen that the thick electrode with the directional pore structure makes up for the shortcomings of excessive internal resistance and poor kinetic performance, and in practical application, the energy density is greatly improved, and the rate performance is better than that of the battery prepared by the traditional electrode sheet. Meanwhile, the carbon soot derived carbon particles conductive agent is used, which not only considers the environmental problem, but also is a new idea and method for converting non-renewable energy waste into sustainable clean energy. The function is improved in terms of lithium affinity activity and conductivity, the polarization behavior of the thick electrode is reduced, the electrode in the battery is more electrically active, the pore structure of the thick electrode is protected to a certain extent, the cycle life and safety performance of the thick electrode battery are improved, and stable output is ensured.

[0013] In the application, the particle size distribution D50 of the positive electrode material in the thick electrode is 5-15 mu m.

[0014] In the application, the carbon soot derived carbon particles are prepared by collecting the carbon soot particles in the automobile exhaust of the automobile using a diesel engine by using a particulate capture technology (DPF). In the application, the particulate capture technology refers to a ceramic filter installed in the exhaust system of the diesel engine, which can capture the carbon soot particles generated during the operation of the diesel engine. According to different working conditions, the particle size distribution D50 of the captured carbon soot particles is 4-20 mu m.

[0015] In the application, the addition amount of the conductive agent is 3-5 wt% of the total solid content of the thick electrode raw material, and the solid content includes the positive electrode material, the binder, the conductive agent and the foaming agent.

[0016] In the application, the addition amount of the carbon soot derived carbon particles accounts for 50-100 wt% of the conductive agent, preferably 60-95 wt%.

[0017] In the application, the preparation method of the derived carbon particles comprises the following steps:

[0018] S1: purify the automobile exhaust carbon soot particles by using aqua regia pickling, cleaning and drying;

[0019] S2: immerse the purified carbon soot particles in a phytic acid solution, stir and stand;

[0020] S3: add metal salt, stir and stand, the phytic acid molecules complex the metal ions and are adsorbed to the purified carbon soot particles;

[0021] S4: after washing and drying the carbon particles, pyrolysis carbonization, cooling, crushing to obtain the carbon soot derived carbon particles.

[0022] In the application, the concentration of the aqua regia in S1 is 70-100 wt%.

[0023] In the application, the cleaning in S1 is cleaning with pure water and ethanol in sequence.

[0024] In the present application, the concentration of the aqueous phytic acid solution in S2 is 0.01-0.1 mol / L.

[0025] In the present application, the standing time in S2 is 20-60 min.

[0026] In the present application, the metal salt in S3 is copper, one or more of nitrate and / or nitrate of aluminum, zinc, iron, nickel, cobalt, tin, and magnesium; preferably, the concentration of the salt is 0.005-0.05 mol / L.

[0027] In the present application, the temperature of S3 is 1-5℃, and the standing time is 2-10 h.

[0028] In the present application, the washing method in S4 is pure water washing.

[0029] In the present application, the pyrolysis carbonization in S4 is pyrolysis carbonization at 800-1000℃ under Ar atmosphere.

[0030] In the present application, the pulverization in S4 adopts an air flow pulverizer; preferably, the D50 distribution of the soot-derived carbon particles after pulverization is 50-100 nm.

[0031] In the present application, the inorganic foaming agent is one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, and ammonium nitrite; preferably, the particle size distribution D50 of the inorganic foaming agent is 1-8 μm; preferably, the addition amount of the inorganic foaming agent is 0.1wt%-1wt% of the total solid content of the thick electrode raw material.

[0032] In the present application, the porosity P of the thick electrode surface is 8%-20%, the pore diameter d is 10-40 μm, the pore spacing b is 50-120 μm, and the pore inclination angle (the deviation angle of the pore central axis compared with the vertical to the electrode piece axis) is 0°-10°.

[0033] In the present application, the slurry coating thickness during the preparation of the thick electrode is 300-500 μm, the drying temperature is 60-130℃, the air blowing drying time is 3-10 min or the vacuum drying time is 20-60 min; preferably, the drying temperature is 110℃, the air blowing drying time is 5 min, and the vacuum drying time is 40 min.

[0034] Another object of the present application is to provide a soot-derived carbon particle product, and the particle size distribution D50 of the carbon particles is 50-100 nm.

[0035] A soot-derived carbon particle is prepared by the above-mentioned method for preparing the carbon particles derived from the thick electrode, and the particle size distribution D50 of the carbon particles is 50-100 nm.

[0036] Another object of the present application is to provide a lithium ion battery.

[0037] A lithium ion battery uses the thick positive electrode with the directional pore structure as the positive electrode.

[0038] Compared with the prior art, the positive effects of the present application are:

[0039] (1) Thanks to the construction of the pore structure, the thick electrode compensates for the shortcomings of excessive internal resistance and poor kinetic performance, and in practical applications, the energy density is improved, and the rate performance is better than that of the battery prepared by the traditional electrode sheet.

[0040] (2) Using carbon soot derived carbon particles as a conductive agent not only takes into account environmental problems, but also is a new idea and method for converting non-renewable energy waste into sustainable clean energy. Functionally, it also improves the lithium activity and conductivity of the electrode sheet, reduces the polarization behavior of the thick electrode, makes the electrode sheet more electrically active in the battery, and to some extent protects the pore structure of the thick electrode from being damaged, improves the cycle life and safety performance of the thick electrode battery, and ensures stable performance output. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The figure is a schematic diagram of the thick electrode structure with a directional pore structure of the present application. Among them, 1 is the prepared directional pore structure, 2 is the positive electrode material particles, and 3 is the positive electrode current collector.

[0042] Figure 2 The figure is a SEM image of the surface of the thick electrode sheet prepared by the present application.

[0043] Figure 3 The figure is a SEM image of the surface of the thick electrode sheet prepared by the present application after drying and 5MPa rolling process.

[0044] Figure 4 The figure is a SEM image of the surface of the full battery prepared by the thick electrode sheet after 500 cycles of 5C rate charging and discharging. DETAILED DESCRIPTION

[0045] In order to better understand the technical solutions of the present application, the following examples will further illustrate the method provided by the present application, but the present application is not limited to the listed examples, and any other known changes within the scope of the claims of the present application should also be included.

[0046] The reaction raw materials used in the following examples and comparative examples are as follows:

[0047] The ternary positive electrode material NMC811 (S85E) used is from Ningbo Rongbai New Energy Technology Co., Ltd.;

[0048] The ternary positive electrode material NMC613 (C6005) used is from Wanhua Chemical Group Co., Ltd.

[0049] The lithium cobaltate (LC9000E) used is from Ningbo Sunwin Group Co., Ltd.

[0050] The binder PVDF (Solef-5130) used is from Dongguan Huapuzhixing New Material Technology Co., Ltd.

[0051] The conductive agent Super P (ENSACO250G) used is from Changzhou Temi Graphite Co., Ltd.

[0052] The dispersion solvent NMP (ALADDIN M100588) used is from Aladdin Reagent (Shanghai) Co., Ltd.

[0053] The inorganic foaming agent ammonium bicarbonate (ALADDIN A110537) used is from Aladdin Reagent (Shanghai) Co., Ltd.

[0054] The phytic acid solution (ALADDIN J838633) used is from Aladdin Reagent (Shanghai) Co., Ltd.

[0055] The metal (copper, aluminum, zinc, iron, nickel, cobalt, tin, magnesium) nitrate used is KM202105, KM202107, KM202109, KM202114, KM202115, KM202118, KM202120, KM202121, Tianjin Kemio Chemical Reagent Co., Ltd.

[0056] A ceramic filter is installed in the diesel engine emission system to capture soot particles generated during the operation of the diesel engine to the end.

[0057] Example 1

[0058] Soot-derived carbon particle preparation: 100g of soot particles (D50 of 4μm) generated in the automobile exhaust of a car using a diesel engine were collected by using a particulate trapping technology (DPF), and the soot particles were sequentially acid washed and purified by using 70wt% aqua regia, pure water, and ethanol, and then dried. The purified soot particles were immersed in 1L of a 0.01mol / L phytic acid solution, stirred, and allowed to stand for 20min. Cobalt nitrate was added to make the salt solution concentration 0.005mol / L, and then stirred and allowed to stand at 1℃ for 2h. The phytic acid molecules complexed with the metal ions and were adsorbed to the purified soot particles. The carbon particles were washed with pure water and dried, and then pyrolyzed and carbonized at 800℃ for 120min under an Ar atmosphere. After cooling, the particles were crushed by an air flow crusher to obtain soot-derived carbon particles with a D50 of 50nm.

[0059] The ternary cathode material NMC811 (S85E)-D50 of 5 pm, binder (PVDF), conductive agent (Super P: carbon soot derived carbon particles-D50 of 50 nm = 1:1), and inorganic foaming agent (ammonium carbonate-D50 of 1 pm) were weighed in a mass ratio of 93.8:3:3:0.2, and the total mass of the solid content was 5 kg. The dispersion solvent (NMP) was weighed in a solid content of 60%. After stirring, the slurry preparation process was completed.

[0060] The prepared slurry was coated on the aluminum foil at a thickness of 300 pm, and vacuum drying was performed at 110°C for 30 min. The dried electrode sheet was rolled to a compact density of 3.3 g / cm 3 The electrode sheet was cut, assembled into a button cell, and subjected to electrochemical testing.

[0061] The prepared slurry was coated on the aluminum foil at a thickness of 300 pm, and air drying was performed at a coating machine speed parameter of 1000 mm / min and a temperature zone setting of 90°C-110°C-110°C for 5 min. The electrode sheet was cut, assembled into a soft package battery, and subjected to electrochemical testing.

[0062] Example 2

[0063] Carbon soot derived carbon particles were prepared: 100 g of carbon soot particles (D50 of 10 pm) generated in automobile exhaust from a diesel engine vehicle were collected using a particulate trap (DPF). The carbon soot particles were sequentially acid washed and purified by drying using 90 wt% aqua regia, pure water, and ethanol. The purified carbon soot particles were immersed in 1 L of a 0.05 mol / L phytic acid solution, stirred, and allowed to stand for 40 min. Aluminum nitrate was added to make the salt solution concentration 0.02 mol / L, and stirring was performed. The solution was allowed to stand at 3°C for 6 h. Phytic acid molecules complexed metal ions and were adsorbed to the purified carbon soot particles. After washing the carbon particles with pure water and drying, pyrolysis carbonization was performed at 900°C for 120 min under an Ar atmosphere. After cooling, the particles were pulverized using an airflow pulverizer to obtain carbon soot derived carbon particles with a D50 of 80 nm.

[0064] The ternary cathode material NMC613 (C6005)-D50 of 10 pm, binder (PVDF), conductive agent (Super P: carbon soot derived carbon particles-D50 of 50 nm = 1:6), and inorganic foaming agent (ammonium bicarbonate-D50 of 4.5 pm) were weighed in a mass ratio of 91.5:3:4:0.5, and the total mass of the solid content was 5 kg. The dispersion solvent (NMP) was weighed in a solid content of 60%. After stirring, the slurry preparation process was completed.

[0065] The prepared slurry was coated on the aluminum foil at a thickness of 400 pm, and vacuum drying was performed at 110°C for 40 min. The dried electrode sheet was rolled to a compact density of 3.3 g / cm3 Cutting the electrode sheet, assembling the button cell, and performing electrochemical tests.

[0066] The prepared slurry was coated on both sides of the aluminum foil at a thickness of 400 pm, the coating machine speed parameter was set to 1000 mm / min, and the temperature zone was set to 90°C-110°C-110°C for air drying. After 5 min of drying, the electrode sheet was cut, the soft-pack battery was assembled, and electrochemical tests were performed.

[0067] Example 3

[0068] Carbon soot-derived carbon particle preparation: 100 g of carbon soot particles (D50 of 20 pm) generated in automobile exhaust from a diesel engine vehicle were collected using a particulate trap (DPF), and the carbon soot particles were sequentially acid washed and purified by drying using 100 wt% aqua regia, pure water, and ethanol. The purified carbon soot particles were immersed in 1 L of a 0.1 mol / L phytic acid solution, stirred, and allowed to stand for 60 min. Nickel nitrate was added to make the salt solution concentration 0.05 mol / L, and the mixture was stirred and allowed to stand at 5°C for 10 h. The phytic acid molecules complexed the metal ions and were adsorbed to the purified carbon soot particles. After the carbon particles were washed with pure water and dried, they were pyrolyzed and carbonized at 1000°C for 120 min under an Ar atmosphere, cooled, and pulverized using an airflow pulverizer to prepare carbon soot-derived carbon particles having a D50 of 100 nm.

[0069] Lithium cobalt oxide (LC9000E) cathode material (D50 of 15 pm), binder (PVDF), conductive agent (Super P: carbon soot-derived carbon particles - D50 of 100 nm = 1:9), and inorganic foaming agent (sodium bicarbonate - D50 of 8 pm) were weighed in a mass ratio of 91:3:5:1, and the total mass of the above solid content was 5 kg. The dispersion solvent (NMP) was weighed in a solid content ratio of 60%. After stirring, the slurry preparation process was completed.

[0070] The prepared slurry was coated on the aluminum foil at a thickness of 500 pm, and vacuum drying was performed at 110°C for 60 min. The dried electrode sheet was roll-pressed to a compacted density of 3.3 g / cm 3 Cutting the electrode sheet, assembling the button cell, and performing electrochemical tests.

[0071] The prepared slurry was coated on both sides of the aluminum foil at a thickness of 500 pm, the coating machine speed parameter was set to 1000 mm / min, and the temperature zone was set to 90°C-110°C-110°C for air drying. After 5 min of drying, the electrode sheet was cut, the soft-pack battery was assembled, and electrochemical tests were performed.

[0072] Comparative Example 1

[0073] In comparison with Example 1, carbon soot-derived carbon particles were not used.

[0074] The ternary cathode material NMC811 (S85E)-D50 of 5 μm, binder (PVDF), conductive agent (Super P) and inorganic foaming agent (ammonium bicarbonate-D50 of 1 μm) were weighed according to the mass ratio of 93.8:3:3:0.2, the total mass of the above solid content was 5 kg, and the dispersion solvent (NMP) was weighed according to the solid content of 60%. Stir evenly, complete the pulp preparation process.

[0075] The prepared slurry was coated on the aluminum foil with a thickness of 300 μm, vacuum dried at 110℃ for 40 min, and the dried electrode sheet was rolled to a compaction density of 3.3 g / cm 3 The electrode sheet was cut, assembled into a button cell, and subjected to electrochemical test.

[0076] The prepared slurry was coated on the aluminum foil with a thickness of 300 μm, coated with a coating machine speed parameter of 800 mm / min, and air dried at a temperature zone of 90℃-110℃-110℃. The electrode sheet was cut, assembled into a soft package battery, and subjected to electrochemical test.

[0077] The main process conditions of the examples and comparative examples and the performance test data of the lithium ion batteries prepared are as follows in Table 1:

[0078] Table 1 Performance test data table of lithium ion batteries

[0079]

[0080] The main process conditions of the examples and comparative examples and the pore structure parameter data of the thick electrode prepared are as follows in Table 2:

[0081] Table 2 Pore structure parameter data table of thick electrode

[0082]

[0083]

[0084] From the electrochemical data in the table, the lithium ion battery made using the thick electrode has higher energy density, rate performance, cycle life and lower charge transfer resistance.

[0085] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. Those skilled in the art can understand that some modifications or adjustments can be made to the present application under the teaching of the present specification. These modifications or adjustments should also be within the scope defined by the claims of the present application.

Claims

1. A thick electrode for a lithium battery cathode having a directional pore structure, characterized in that, The thick electrode positive electrode material is one or more of nickel-cobalt-manganese ternary material, lithium cobaltate material, lithium manganate material, the thick electrode conductive agent is small particle super conductive carbon black SuperP and carbon soot derived carbon particles, the thick electrode adopts inorganic foaming agent to form pore channel; The preparation method of the carbon soot derived carbon particles comprises the following steps: S1: purifying automobile exhaust soot particles with aqua regia, cleaning, drying; S2: immersing the purified carbon soot particles into phytic acid solution, stirring, standing; S3: adding metal salt, stirring, standing, phytic acid molecules complexing metal ions and adsorbing to the purified carbon soot particles; S4: washing the carbon soot particles and drying, pyrolyzing carbonization, cooling, crushing to obtain carbon soot derived carbon particles; The addition amount of the carbon soot derived carbon particles accounts for 50wt%-100wt% of the conductive agent. The slurry coating thickness of the thick electrode is 300μm-500μm.

2. The thick electrode according to claim 1, wherein The particle size distribution D50 of the positive electrode material in the thick electrode is 5μm-15μm.

3. The thick electrode according to claim 1 or 2, characterized by The carbon soot derived carbon particles are prepared by collecting the carbon soot particles in automobile exhaust generated by the automobile using diesel engine by using the DPF (diesel particulate filter) technology. The addition amount of the conductive agent is 3wt%-5wt% of the total solid content of the thick electrode raw materials, and the solid content includes the positive electrode material, the binder, the conductive agent and the foaming agent. The addition amount of the carbon soot derived carbon particles accounts for 60wt%-95wt% of the conductive agent.

4. The thick electrode according to claim 1, wherein The concentration of the aqua regia in S1 is 70wt%-100wt%. The cleaning in S1 is sequentially using pure water and ethanol.

5. The thick electrode according to claim 1, wherein The concentration of the phytic acid solution in S2 is 0.01mol / L-0.1mol / L. The standing time in S2 is 20min-60min.

6. The thick electrode according to claim 1, wherein The metal salt in S3 is one or more of copper, aluminum, zinc, iron, nickel, cobalt, tin and magnesium nitrate. The temperature in S3 is 1℃-5℃, and the standing time is 2h-10h.

7. The thick electrode according to claim 6, wherein The concentration of the metal salt in S3 is 0.005mol / L-0.05mol / L.

8. The thick electrode according to claim 1, wherein The washing method in S4 is pure water washing. The pyrolyzing carbonization in S4 is pyrolyzing carbonization at 800℃-1000℃ under Ar atmosphere. The crushing in S4 adopts the jet mill.

9. The thick electrode according to claim 8, wherein The D50 distribution of the carbon soot derived carbon particles after crushing in S4 is 50nm-100nm.

10. The thick electrode as claimed in claim 1, wherein The inorganic foaming agent is one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonium nitrite.

11. The thick electrode as claimed in claim 10, wherein The particle size distribution D50 of the inorganic foaming agent is 1μm-8μm. The addition amount of the inorganic foaming agent is 0.1wt%-1wt% of the total solid content of the thick electrode raw materials.

12. The thick electrode as claimed in claim 1, wherein The porosity P of the surface of the thick electrode is 8%-20%, the pore diameter d is 10μm-40μm, the pore spacing b is 50μm-120μm, and the pore inclination angle, i.e. the deviation angle of the pore central axis compared with the vertical to the electrode plate axis, is 0°-10°.

13. The thick electrode as claimed in claim 1, wherein The slurry coating and drying temperature of the thick electrode is 60℃-130℃, and the air blowing drying time is 3min-10min or the vacuum drying time is 20min-60min.

14. A soot-derived carbon particle obtained by the method for producing a soot-derived carbon particle in a thick electrode according to any one of claims 1 to 13, characterized by The particle size distribution D50 of the carbon particles is 50nm-100nm.

15. A lithium ion battery using the thick electrode of the lithium battery anode with a directional pore structure according to any one of claims 1-13 as an anode.

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