Antimony-containing negative-electrode active material and preparation method therefor, and lithium-ion battery

Abstract

An antimony-containing negative-electrode active material, containing graphite and an antimony-carbon composite material, wherein the antimony-carbon composite material comprises a metallic antimony kernel and a carbon cladding layer; in a Raman spectrum of the antimony-containing negative-electrode active material, the value of ID / IG ranges from 0.52 to 1.54; and in an X-ray diffraction pattern of the antimony-containing negative-electrode active material, the value of C110 / C002 ranges from 0.043 to 0.085. The antimony-containing negative-electrode active material has good cycling stability and a relatively high platform voltage. The carbon cladding layer contained in the antimony-carbon composite material can provide reliable protection for the metallic antimony kernel and can also improve the conductivity of an antimony-based negative electrode material. The graphite contained in the antimony-containing negative-electrode active material can be used as a load for the antimony-carbon composite material, thereby further improving the conductivity and lithium storage performance of the antimony-based negative electrode material.

Description

Antimony-containing negative electrode active material and preparation method thereof, and lithium ion battery Technical Field

[0001] The present application belongs to the technical field of lithium-ion batteries, and specifically relates to an antimony-containing negative electrode active material and a preparation method thereof, and a lithium-ion battery. Background Art

[0002] Rechargeable lithium-ion batteries (Li-ion batteries) have been widely used in power batteries, consumer electronics (C&C) batteries, and energy storage due to their high operating voltage, high energy density, lightweight, long cycle life, and environmental friendliness. New energy vehicles, mobile phones, and other products are demanding higher capacity from Li-ion batteries, necessitating the accelerated adoption of high-capacity anode materials. Graphite, a traditional anode material, offers excellent cycle stability and rate performance, but its theoretical capacity is only 372 mAh / g. Current graphite anode capacity is already close to its theoretical capacity, making it difficult to meet market demand for high-capacity Li-ion batteries. To increase battery density, new anode materials need to be developed.

[0003] In recent years, antimony-based materials have shown great potential as negative electrode materials for lithium-ion batteries. Antimony, with a theoretical capacity of 660 mAh / g and abundant reserves, has a low discharge voltage, making it a promising negative electrode material for lithium-ion batteries. Although antimony has a higher capacity than graphite, antimony negative electrodes undergo alloying and dealloying reactions during the charge and discharge process. This high capacity is accompanied by a significant volume expansion (290%). This significant volume expansion leads to the fragmentation and pulverization of the electrode material, rapidly degrading the battery's cycling performance.

[0004] Summary of the Invention

[0005] In order to improve the structural stability of lithium-ion batteries using antimony-based negative electrode active materials during cyclic charge and discharge, the present application provides an antimony-containing negative electrode active material and a preparation method thereof, and a lithium-ion battery.

[0006] According to a first aspect of the present application, an antimony-containing negative electrode active material is provided: the antimony-containing negative electrode active material comprises graphite and an antimony-carbon composite material, the antimony-carbon composite material comprises a metal antimony core and a carbon coating layer; in the Raman spectrum of the antimony-containing negative electrode active material, the peak intensity of the D peak is D The peak intensity of the G peak I G Ratio I D / I G =0.52~1.54; In the X-ray diffraction pattern of the antimony-containing negative electrode active material, the peak intensity C of the (110) surface characteristic peak 110 The peak intensity C of the characteristic peak of (002) surface 002 Ratio C 110 / C 002 =0.043~0.085.

[0007] Preferably, in the Raman spectrum of the antimony-containing negative electrode active material, the peak intensity of the D peak is D The peak intensity of the G peak I G Ratio I D / I G ≥1.

[0008] Preferably, in the X-ray diffraction pattern of the antimony-containing negative electrode active material, the peak intensity C of the characteristic peak of the (110) plane is 110 The peak intensity C of the characteristic peak of (002) surface 002 Ratio C 110 / C 002 =0.05~0.065.

[0009] Preferably, in the antimony-containing carbon composite material, the mass of the metal antimony: the mass of the carbon coating layer = 0.4-2.5: 0.4-4.

[0010] Preferably, in the antimony-containing negative electrode active material, the mass of metal antimony:the mass of graphite=4-26:5-50.

[0011] Preferably, the antimony-containing negative electrode active material D 90 =8~10μm, D of antimony-containing negative electrode active material 10 =0.5~1.5μm.

[0012] Preferably, the antimony-containing negative electrode active material D 50 =2.5~5μm.

[0013] Preferably, the specific surface area of ​​the antimony-containing negative electrode active material is 1.5 to 4.5 m 2 / g.

[0014] The antimony-containing negative electrode active material provided in the present application has excellent cycle stability and a high platform voltage. The carbon coating layer included in the antimony-carbon composite material contains a large amount of amorphous carbon, so that the carbon coating layer can form a uniform and dense coating layer on the surface of the metal antimony core. The carbon coating layer is not easy to break or fall off from the surface of the metal antimony core, and can provide reliable protection for the metal antimony core. As a result, the metal antimony can be effectively separated from the electrolyte, thereby reducing the interfacial side reactions between the metal antimony and the electrolyte, inhibiting the volume expansion of the metal antimony during the cyclic charge and discharge process, and avoiding the rupture of the SEI film caused by the expansion of the metal antimony. At the same time, the close contact between the carbon coating layer and the metal antimony can improve the conductivity of the antimony-based negative electrode material. Among them, the graphite contained in the antimony-containing negative electrode active material of the present application can be used as a carrier of the antimony-carbon composite material. The gaps formed between the graphites can provide a buffer space for the expansion stress generated by the expansion of the antimony-based material, so as to avoid the expansion of the antimony-carbon composite material causing obvious deformation of the negative electrode sheet using it, thereby further enhancing the structural stability of the negative electrode sheet using the antimony-based negative electrode material. Moreover, the three-dimensional skeleton constructed by graphite has excellent conductivity. Using it as a load for the antimony-carbon composite material can further improve the conductivity and lithium storage performance of the antimony-based negative electrode material.

[0015] According to the second aspect of the present application, a method for preparing the antimony-containing negative electrode active material as described above is provided, comprising the following operations: S1. slurrying an antimony source, an organic carbon source, graphite, and a solvent to obtain a reaction slurry; S2. completely volatilizing the solvent in the reaction slurry and grinding the remaining dry material to obtain a precursor; S3. placing the precursor in a reaction system provided with a reducing agent, and then raising the temperature of the reaction system to 500-1000°C, so that: the antimony source is converted into metallic antimony under the action of the reducing agent, and the organic carbon source undergoes a pyrolysis reaction to form a carbon coating layer on the surface of the metallic antimony.

[0016] Preferably, in S1, the particle size of the antimony source used is 100-200 nm.

[0017] Preferably, in S1, the organic carbon source used includes at least one of glucose, asphalt, polyvinyl alcohol, polyacrylic acid, and polybutyl acrylate.

[0018] Preferably, in S1, the particle size D of the graphite used is 50 =5~20μm.

[0019] Preferably, in S1, the solvent used includes at least one of water, ethanol, methanol, toluene, and tetrahydrofuran.

[0020] Preferably, in the temperature increasing operation involved in S3, the temperature increasing rate of the reaction system is 1-10°C / min.

[0021] Preferably, in S3, the temperature of the reaction system is raised to 500-1000° C. and then maintained at that temperature for 2-10 hours.

[0022] According to a third aspect of the present application, a lithium-ion battery is provided, comprising a negative electrode, wherein the negative electrode active material layer of the negative electrode comprises the above antimony-containing negative electrode active material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a Raman spectrum of the antimony-containing negative electrode active material obtained in Example 1;

[0024] FIG2 is the X-ray diffraction spectrum of the antimony-containing negative electrode active material obtained in Example 1. DETAILED DESCRIPTION

[0025] In order to enable people in this technical field to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0026] Example 1

[0027] The raw materials used in this embodiment include: antimony source, antimony trioxide, spherical, D 50 =100 nm; dispersant, polyvinylpyrrolidone; organic carbon source, glucose; graphite, flake, D 50 =5μm; solvent: water. The above raw materials were used to prepare the antimony-containing negative electrode active material according to the following operation:

[0028] S1. Weigh the raw materials according to the mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 1:1:6:1:100, mix the weighed raw materials, and use ultrasonic dispersion for 30 minutes while providing high-speed stirring at a stirring speed of 100 r / min to obtain a uniform reaction slurry.

[0029] S2. The reaction slurry obtained in S1 was stirred under heating conditions until the solvent therein was completely volatilized, the stirring speed was 100 r / min, the heating temperature was 50°C, and then the remaining material was dried at 50°C, and then the remaining dry material was ground to obtain a precursor.

[0030] S3. Place the precursor prepared in S2 into a muffle furnace filled with a reducing gas, wherein the reducing gas is an argon-hydrogen mixture with a hydrogen volume content of 5%. Then, heat the muffle furnace to 600°C at a heating rate of 2°C / min and keep it warm for 2 hours. During this process, antimony trioxide is converted into metallic antimony, and glucose undergoes a thermal decomposition reaction to form a carbon coating layer on the surface of the metallic antimony. After the reaction is completed, an antimony-containing negative electrode active material is obtained.

[0031] Example 2

[0032] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, and referring to the method for preparing an antimony-containing negative electrode active material provided in Example 1, the antimony-containing negative electrode active material of this example was prepared. The difference from Example 1 lies in the raw material ratio, which is weighed according to the mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 2:1:6:1:100. Aside from these differences, the raw materials and process steps used in this example strictly adhere to those of Example 1.

[0033] Example 3

[0034] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, and referring to the method for preparing an antimony-containing negative electrode active material provided in Example 1, the antimony-containing negative electrode active material of this example was prepared. The difference from Example 1 lies in the raw material ratio, which is weighed according to the mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 3:1:6:1:100. Aside from these differences, the raw materials and process steps used in this example strictly adhere to those of Example 1.

[0035] Example 4

[0036] The difference between the raw materials used in this embodiment to prepare the antimony-containing negative electrode active material and those in Example 1 is that the graphite used in this embodiment is D 50 =10μm flake graphite. Except for this, the other raw materials used in this embodiment are consistent with those in the embodiment. Using the above raw materials, the antimony-containing negative electrode active material of this embodiment was prepared according to the method for preparing the antimony-containing negative electrode active material in Example 1. All process steps are strictly consistent with those in Example 1.

[0037] Example 5

[0038] The difference between the raw materials used in this embodiment to prepare the antimony-containing negative electrode active material and those in Example 1 is that the graphite used in this embodiment is D 50 =20 μm flake graphite. Except for this, the other raw materials used in this embodiment are consistent with those in Example 1. Using the above raw materials, the antimony-containing negative electrode active material of this embodiment was prepared according to the method for preparing an antimony-containing negative electrode active material in Example 1, and all process steps were strictly consistent with those in Example 1.

[0039] Example 6

[0040] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, the antimony-containing negative electrode active material of this example was prepared in accordance with the method for preparing the antimony-containing negative electrode active material provided in Example 1. The difference from Example 1 is that, in step S3 of preparing the antimony-containing negative electrode active material, the muffle furnace is maintained at a temperature of 700°C. Aside from these differences, all process steps involved in preparing the antimony-containing negative electrode active material in this example are strictly consistent with those in Example 1.

[0041] Example 7

[0042] This embodiment uses the same raw materials as in Example 1 for preparing the antimony-containing negative electrode active material. The difference from Example 1 is that the dispersant used in this embodiment is carboxymethyl cellulose and the organic carbon source used is polyacrylic acid. Other than these, the other raw materials used in preparing the antimony-containing negative electrode active material in this embodiment are the same as in Example 1. The antimony-containing negative electrode active material is prepared using the above raw materials in accordance with the following operations:

[0043] S1. Weigh the raw materials according to the mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 1:1:6:1:100, mix the weighed raw materials, and use ultrasonic dispersion for 30 minutes while providing high-speed stirring at a stirring speed of 100 r / min to obtain a uniform reaction slurry.

[0044] S2. The reaction slurry obtained in S1 was stirred under heating conditions until the solvent therein was completely volatilized, the stirring speed was 100 r / min, the heating temperature was 50°C, and then the remaining material was dried at 50°C, and then the remaining dry material was ground to obtain a precursor.

[0045] S3. Place the precursor prepared in S2 into a muffle furnace filled with a reducing gas, wherein the reducing gas is an argon-hydrogen mixture with a hydrogen volume content of 5%. Then, heat the muffle furnace to 800°C at a heating rate of 5°C / min and keep it warm for 2 hours. During this process, antimony trioxide is converted into metallic antimony, and glucose undergoes a thermal decomposition reaction to form a carbon coating layer on the surface of the metallic antimony. After the reaction is completed, an antimony-containing negative electrode active material is obtained.

[0046] Example 8

[0047] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, and referring to the method for preparing an antimony-containing negative electrode active material provided in Example 1, the antimony-containing negative electrode active material of this example was prepared. The difference from Example 1 lies in the raw material ratio, which is weighed according to a mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 1:1:0.15:1:100. Aside from these differences, the raw materials and process steps used in this example strictly adhere to those of Example 1.

[0048] Example 9

[0049] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, and referring to the method for preparing an antimony-containing negative electrode active material provided in Example 1, the antimony-containing negative electrode active material of this example was prepared. The difference from Example 1 lies in the raw material ratio, which is weighed according to a mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 1:1:11:1:100. Aside from these differences, the raw materials and process steps used in this example strictly adhere to those of Example 1.

[0050] Example 10

[0051] The raw materials used to prepare the antimony-containing negative electrode active material in this example are the same as those in Example 1. Using these raw materials, and referring to the method for preparing an antimony-containing negative electrode active material provided in Example 1, the antimony-containing negative electrode active material of this example was prepared. The difference from Example 1 lies in the raw material ratio, which is weighed according to the mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 1:1:6:15:100. Aside from these differences, the raw materials and process steps used in this example strictly adhere to those of Example 1.

[0052] Comparative Example 1

[0053] The raw materials used to prepare the antimony-containing negative electrode active material in this comparative example do not include graphite; the remaining raw materials are the same as those in Example 1. Using these raw materials, the antimony-containing negative electrode active material of this comparative example was prepared with reference to the method for preparing an antimony-containing negative electrode active material provided in Example 1. Unlike Example 1, the addition of graphite is omitted in this comparative example. Aside from these differences, the raw materials and process steps used in this comparative example strictly adhere to those of Example 1.

[0054] Comparative Example 2

[0055] The raw materials used to prepare the antimony-containing negative electrode active material in this comparative example are the same as those in Example 1. Using these raw materials, the antimony-containing negative electrode active material of this comparative example was prepared according to the method for preparing the antimony-containing negative electrode active material provided in Example 1. The difference from Example 1 is that, in step S3 of preparing the antimony-containing negative electrode active material, the muffle furnace was maintained at a temperature of 1100°C. Aside from these differences, all process steps involved in preparing the antimony-containing negative electrode active material in this comparative example strictly adhered to those in Example 1.

[0056] Comparative Example 3

[0057] The raw materials used to prepare the antimony-containing negative electrode active material in this comparative example are the same as those in Example 1. Using these raw materials, the antimony-containing negative electrode active material of this comparative example was prepared according to the method for preparing the antimony-containing negative electrode active material provided in Example 1. The difference from Example 1 is that, in step S3 of preparing the antimony-containing negative electrode active material, the muffle furnace was maintained at a temperature of 400°C. Aside from these differences, all process steps involved in preparing the antimony-containing negative electrode active material in this comparative example strictly adhered to those in Example 1.

[0058] Comparative Example 4

[0059] The raw materials used to prepare the antimony-containing negative electrode active material in this embodiment are the same as those in Example 1. The antimony-containing negative electrode active material of this embodiment was prepared using the above raw materials and with reference to the method for preparing the antimony-containing negative electrode active material provided in Example 1. The difference from Example 1 is that the raw materials were weighed according to a mass ratio of antimony trioxide: polyvinyl pyrrolidone: glucose: graphite: solvent water = 2.5:1:6:1:100. Aside from these differences, the raw materials used in this embodiment are the same as those used in Example 1 to prepare the antimony-containing negative electrode active material. The antimony-containing negative electrode active material of this comparative example was prepared using the above raw materials and with reference to the method for preparing the antimony-containing negative electrode active material provided in Example 1. The difference from Example 1 is that in step S3 of preparing the antimony-containing negative electrode active material, the muffle furnace's holding temperature was 550°C. Aside from these differences, all process steps involved in preparing the antimony-containing negative electrode active material in this comparative example are strictly consistent with those in Example 1.

[0060] Comparative Example 5

[0061] The types of raw materials used in this comparative example to prepare the antimony-containing negative electrode active material are different from those in Example 1 as follows: the graphite used in this comparative example is D 50= 20 μm flake graphite; the dispersant used in this comparative example is carboxymethyl cellulose, and the organic carbon source used is polyacrylic acid. Except for the above, the other raw materials used in this comparative example are consistent with those in Example 1. Using the above raw materials, the antimony-containing negative electrode active material of this comparative example was prepared according to the method for preparing an antimony-containing negative electrode active material in Example 1, with all process steps strictly consistent with those in Example 1.

[0062] Test Case

[0063] 1. Test subjects and control subjects

[0064] The antimony-containing negative electrode active materials prepared in Examples 1 to 7 and Comparative Examples 1 to 6 were used as test objects in this test example; and metallic antimony was used as the negative electrode active material, which was marked as a control object.

[0065] 2. Assembly of lithium-ion batteries

[0066] The test objects and control objects from different examples and comparative examples were used as negative electrode active materials. A mass ratio of negative electrode active material: conductive agent carbon black (sp): binder sodium carboxymethyl cellulose (CMC) was prepared at 8:1:1. These materials were mixed to form a slurry. The resulting mixed slurry was then mixed and ground to produce a uniformly dispersed battery slurry. The battery slurry was evenly coated on the surface of a copper foil, then vacuum-dried at 60°C for 12 hours and pressed into sheets to serve as negative electrode sheets. A lithium sheet was used as the positive electrode sheet, and Celgard 2500 was used as the separator. An electrolyte was prepared using EC, DEC, FEC, and LiPF6. EC and DEC were first mixed at a mass ratio of 1:1, and then LiPF6 and FEC were added to the resulting mixed organic solvent to produce an electrolyte containing 1M LiPF6 and 5% FEC. Finally, a button-type half-cell was assembled in a glove box using the above-mentioned positive electrode sheet, negative electrode sheet, separator, and electrolyte.

[0067] 3. Test items

[0068] (1) Raman spectroscopy

[0069] According to the GB / T 33252-2016 laser confocal micro-Raman spectrometer performance test method, the antimony-containing negative electrode active material was tested by Raman spectroscopy, and the peak value at 1300 cm was read in the measured Raman spectrum. -1 Peak intensity of D at nearby position I D , the reading peak is at 1600cm -1 The peak intensity of G peak at the nearby position I G .

[0070] (2) X-ray diffraction spectrum detection

[0071] According to T / CSTM 00166.2-2020 Graphene Material Characterization Part 2 X-ray Diffraction Method, the antimony-containing negative electrode active material was tested by X-ray diffraction spectrum, and the peak intensity C of the characteristic peak of the (110) plane was read. 110 The peak intensity C of the characteristic peak of (002) surface 002 .

[0072] (3) Particle size test

[0073] The particle size of the antimony-containing negative electrode active material was tested according to GB / T 19077_1-2003 particle size analysis-laser diffraction method.

[0074] (4) Cycle performance test

[0075] This study used a standard charge and discharge cycle test method to evaluate the cycle performance of button batteries. First, the battery was charged to a full state using a constant current and constant voltage charging method, and left to stand for a period of time to ensure that the electrochemical reaction inside the battery reached stability. Then, the battery was discharged with a fixed constant current load, and the voltage change during the discharge process and the corresponding discharge capacity were recorded. Among them, in the selection of button battery samples, button battery samples with similar parameters were selected from the button battery samples prepared using the antimony-containing negative electrode active material provided by the same embodiment or comparative example (twenty repeated button battery samples were selected for each antimony-containing negative electrode active material provided in each embodiment or comparative example, and each button battery sample was a repeat), to ensure that the differences between the button battery samples prepared using the same antimony-containing negative electrode active material were as small as possible.

[0076] The prepared button-type half-cell was discharged at a constant current (0.1 mA / mg, 0.005 V), allowed to rest for 5 minutes, and then charged at a constant current (0.1 mA / mg, 3.000 V). The number of cycles required for the capacity retention of the button-type half-cell to drop to 80% was recorded.

[0077] 4. Test Results

[0078] The test results of this test example are shown in Table 1. As a control object, a lithium-ion battery was made using only metal antimony as the negative electrode active material. During the process of cyclic charge and discharge of the lithium-ion battery, the metal antimony will undergo significant volume expansion. As the number of cycles of charge and discharge increases during the test, the capacity retention rate of the lithium-ion battery obtained thereby decreases significantly more than that of other test products. In addition, after the test, the control object and other test objects were disassembled, and it can be seen that the negative electrode of the control object has undergone significant expansion compared to before the lithium-ion battery participated in the cyclic test, and its negative electrode active material layer has also been damaged. Compared with the negative electrode of the control object, the negative electrode of the other test objects can better maintain its shape before participating in the cyclic test after completing the test of this test example. The antimony-containing negative electrode active materials prepared in Examples 1 to 10 and Comparative Examples 1 to 5 all have a carbon coating layer coated on the surface of the metallic antimony. The carbon coating layer can isolate the metallic antimony from the electrolyte, reduce the side reaction between the electrolyte and the metallic antimony, and to a certain extent limit the expansion of the metallic antimony. Therefore, compared with the control objects using only metallic antimony as the negative electrode material, the lithium-ion batteries prepared in these examples and comparative examples respectively have negative electrodes with higher structural stability, so that these lithium-ion batteries exhibit better cycle characteristics in tests.

[0079] In Examples 1-10 and Comparative Examples 1-5, the antimony-containing negative electrode active material prepared in Comparative Example 1 does not contain graphite. The test results of this test example show that the number of cycles measured for the lithium-ion battery prepared in Comparative Example 1 is significantly less than the number of cycles measured for the lithium-ion batteries prepared in the other Examples and Comparative Examples. This demonstrates that the antimony-containing negative electrode active material provided herein, by compounding graphite with an antimony-carbon composite material, can effectively optimize the cycling performance of lithium-ion batteries using the antimony-carbon composite material as the negative electrode active material.

[0080] The negative electrode active materials used in Examples 1 to 10 and Comparative Examples 2 to 5 are all antimony-containing negative electrode active materials obtained by compounding graphite and antimony-carbon composite materials (including a metal antimony core and a carbon coating layer). However, compared with the lithium ion batteries prepared in Comparative Examples 2 to 5, the lithium ion batteries provided by Examples 1 to 10 have significantly higher measured cycle numbers. The antimony-containing negative electrode active materials prepared in Examples 1 to 10 have both I D / I G =0.52~1.54 Raman spectrum characteristics, and also has C 110 / C 002= 0.043 ~ 0.085 X-ray diffraction pattern characteristics, in the antimony-containing negative electrode active material with the above characteristics, the antimony-carbon composite material included has excellent structural stability, the carbon coating layer can form a uniform and dense coating layer on the surface of the metal antimony core, which is not easy to break and not easy to fall off from the surface of the metal antimony core, and can provide reliable protection for the metal antimony core. In addition, the graphite and the antimony-carbon composite material are compounded in an appropriate proportion, and the gaps formed between the graphites can provide a buffer space for the expansion stress generated by the expansion of the antimony-based material, so as to avoid the expansion of the antimony-carbon composite material causing obvious deformation of the negative electrode sheet using it, thereby further enhancing the structural stability of the negative electrode sheet using the antimony-based negative electrode material.

[0081] Furthermore, among the antimony-containing negative electrode active materials prepared in Examples 1 to 10, the Raman spectra of the antimony-containing negative electrode active materials of Examples 1, 2, and 5 further conform to I D / I G ≥1, the number of cycles corresponding to the lithium-ion batteries prepared in these three embodiments is significantly greater, which shows that when the antimony-containing negative electrode active material provided in this application is used, the Raman spectrum is consistent with I D / I G The use of antimony-containing negative electrode active materials with a specific RI of ≥1 in lithium-ion batteries can further optimize the cycling characteristics of lithium-ion batteries. Among all the test subjects, the lithium-ion battery provided by Example 1 had the best cycling performance. The corresponding Raman and X-ray diffraction spectra of the antimony-containing negative electrode active material used therein are shown in Figures 1 and 2, respectively.

[0082] Table 1. Test result statistics of this test case

[0083] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the technical solutions of the present application can be modified or replaced by equivalents, but these modifications or replacements are all within the scope of protection of the present application.

Claims

1. An antimony-containing negative electrode active material, characterized in that: The antimony-containing negative electrode active material comprises graphite and an antimony-carbon composite material, wherein the antimony-carbon composite material comprises a metal antimony core and a carbon coating layer; In the Raman spectrum of the antimony-containing negative electrode active material, the peak intensity of the D peak is D The peak intensity of the G peak is G Ratio I D / I G =0.52~1.54; In the X-ray diffraction spectrum of the antimony-containing negative electrode active material, the peak intensity C 110 The peak intensity of the characteristic peak of (002) surface C 002 Ratio C 110 / C 002 =0.043~0.

085.

2. The antimony-containing negative electrode active material according to claim 1, characterized in that: In the Raman spectrum of the antimony-containing negative electrode active material, the peak intensity of the D peak is D The peak intensity of the G peak is G Ratio I D / I G ≥1.

3. The antimony-containing negative electrode active material according to claim 2, characterized in that: In the X-ray diffraction spectrum of the antimony-containing negative electrode active material, the peak intensity C 110 The peak intensity of the characteristic peak of (002) surface C 002 Ratio C 110 / C 002 =0.05~0.

065.

4. The antimony-containing negative electrode active material according to claim 1, characterized in that: In the antimony-carbon composite material, the mass of metal antimony: the mass of the carbon coating layer = 0.4-2.5: 0.4-4.

5. The antimony-containing negative electrode active material according to claim 1, characterized in that: In the antimony-containing negative electrode active material, the mass of metal antimony: the mass of graphite = 4-26: 5-50.

6. The antimony-containing negative electrode active material according to claim 1, characterized in that: The antimony-containing negative electrode active material D 90 =8-10 μm, the antimony-containing negative electrode active material D 10 =0.5~1.5μm.

7. The antimony-containing negative electrode active material according to claim 5, characterized in that: The antimony-containing negative electrode active material D 50 =2.5~5μm.

8. The antimony-containing negative electrode active material according to claim 1, characterized in that: The specific surface area of ​​the antimony-containing negative electrode active material is 1.5 to 4.5 m 2 / g 9. The method for preparing an antimony-containing negative electrode active material according to any one of claims 1 to 7, characterized in that: The following operations are included: S1. slurrying using an antimony source, an organic carbon source, graphite, and a solvent to obtain a reaction slurry; S2. The solvent of the reaction slurry is completely evaporated, and the remaining dry material is ground to obtain a precursor; S3. placing the precursor into a reaction system provided with a reducing agent, and then raising the temperature of the reaction system to 500-1000°C, so that: the antimony source is converted into metallic antimony under the action of the reducing agent, and the organic carbon source undergoes a pyrolysis reaction to form the carbon coating layer on the surface of the metallic antimony.

10. A lithium ion battery, characterized in that: The invention comprises a negative electrode, wherein a negative electrode active material layer of the negative electrode comprises the antimony-containing negative electrode active material according to any one of claims 1 to 8.

Images