Porous cobalt-antimony alloy negative electrode material, preparation method thereof, and battery

Abstract

The present invention discloses a porous cobalt-antimony alloy negative electrode material and its preparation method and battery, belonging to the technical field of negative electrode materials. The preparation method comprises the following steps: step 1, promoting Co 3+ and Sb 3+ The catalyst is reacted with the chelating resin to obtain a complex; Step 2, the catalyst and the complex are fully mixed to obtain a precursor, and then the precursor is calcined under a protective gas, and after the calcination, the porous cobalt antimony alloy negative electrode material is obtained by washing with water; wherein the catalyst includes Na + Substances and K-containing + In the present invention, firstly, Co and Sb are uniformly coordinated and complexed in the chelate resin at the atomic level, and secondly, Na-containing + Substances and K-containing + The material acts as a catalyst during calcination, wherein sodium is reduced during the high-temperature process to form an alloy with Co-Sb. Then, since Co-Sb is insoluble in water while sodium is soluble in water, Na in the alloy is washed out, thereby forming a porous Co-Sb alloy, which reserves effective space for the expansion of the Co-Sb alloy.

Description

Technical Field

[0001] The present invention relates to the technical field of negative electrode materials, and in particular to a porous cobalt-antimony alloy negative electrode material, a preparation method thereof, and a battery. Background Art

[0002] Research on negative electrode materials has revealed that certain alloy compounds may offer new anode materials for lithium-ion batteries. For example, Si (silicon), Ge (germanium), Sn (tin), Pb (lead), Al (aluminum), Ga (gallium), and Sb (antimony) all possess high lithium storage capacities, making alloys promising candidates for new lithium-ion battery negative electrode materials.

[0003] Among them, elemental Sb can alloy with sodium ions to form Na-Sb alloys, which offer high theoretical specific capacity and a moderate operating voltage (0.5-0.8 vs Na+ / Na), making them a preferred anode material for sodium-ion batteries (SIBs). However, during the charge-discharge process, Sb-based materials suffer from problems such as easy agglomeration, large volume expansion, and continuous SEI growth. These problems lead to the shattering of the electrode material structure, slow ion transport kinetics, and loss of active materials during long cycles. This, in turn, reduces battery cycling stability, directly impacting the battery's electrochemical performance and hindering the further application of Sb-based materials.

[0004] Based on this, how to improve the stability and rate capability of negative electrode materials made of Sb-based materials has become a current research hotspot. Summary of the Invention

[0005] In order to solve the problem that the existing Sb-based materials are easy to agglomerate and expand in volume, resulting in poor stability and rate capability of the negative electrode materials made therefrom, one of the objectives of the present invention is to provide a method for preparing a porous cobalt-antimony alloy negative electrode material.

[0006] The present invention solves the above technical problems with the following technical solutions: A method for preparing a porous cobalt-antimony alloy negative electrode material comprises the following steps:

[0007] Step 1: Encourage Co 3+ and Sb 3+ Carrying out complexation reaction with chelating resin to obtain a complex;

[0008] Step 2: Fully mix the catalyst and the complex to obtain a precursor, then calcine the precursor under protective gas, and wash with water after calcination to obtain a porous cobalt-antimony alloy negative electrode material; wherein the catalyst includes Na + Substances and K-containing + substance.

[0009] On the basis of the above technical solution, the present invention can also be improved as follows:

[0010] Further, Co 3+ and Sb 3+ The molar ratio is 1:9~3:7.

[0011] Further, Co 3+ Derived from cobalt salts, Sb 3+ Derived from antimony salt; the mass ratio of the total mass of cobalt salt and antimony salt to the mass ratio of chelating resin is 1: (1~4).

[0012] Furthermore, the chelate resin is an iminodiacetic acid type chelate resin.

[0013] Furthermore, the Na + and K + The molar ratio is 1:9~9:1.

[0014] Furthermore, Na + The substance is any one of sodium oxide, sodium peroxide, sodium hydroxide and sodium-containing inorganic salts; containing K + The substance is any one of potassium oxide, potassium peroxide, potassium hydroxide and potassium-containing inorganic salts.

[0015] Furthermore, the calcination conditions are: calcination temperature is 500~1200°C, and calcination time is 5min~10h.

[0016] Furthermore, the protective gas is argon.

[0017] The second object of the present invention is to provide a porous cobalt-antimony alloy negative electrode material obtained by the preparation method in the first object.

[0018] The third object of the present invention is to provide a battery, which includes the porous cobalt-antimony alloy negative electrode material in the second object as the negative electrode.

[0019] The present invention has the following beneficial effects:

[0020] The porous cobalt-antimony alloy anode material prepared by the present invention, due to the atomic dispersion of Co-Sb in a multi-level porous three-dimensional graphene structure, combined with the anchoring effect of Co and the porous Co-Sb alloy, can fundamentally suppress the volume change of Sb, thereby significantly improving the cycling stability of the antimony anode. In addition, the in-situ multi-level porous three-dimensional graphene structure effectively blocks direct contact between Co-Sb and the electrolyte, thereby reducing the capacity decay caused by SEI, further improving the Coulombic efficiency and stability during the cycle. In addition, this multi-level porous structure can also promote electrolyte infiltration, significantly reducing the ionic impedance of the composite material. Combined with the interaction between the in-situ formed Sb, Co-C, and carbon, a complete conductive network is constructed, effectively improving the rate performance of the composite material.

[0021] Moreover, according to subsequent tests, it can be seen that the porous cobalt-antimony alloy negative electrode material prepared in the present invention has good first coulombic efficiency, 1C specific capacity and 1C capacity retention rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a macroscopic TEM (transmission electron microscope) image of the porous cobalt-antimony alloy negative electrode material prepared in the present invention;

[0023] Figure 2 This is a microscopic TEM (transmission electron microscope) image of the porous cobalt-antimony alloy negative electrode material prepared in the present invention;

[0024] Figure 3 The BET (specific surface area) test results of the porous cobalt-antimony alloy negative electrode material prepared in the present invention are shown in FIG. (a) is an adsorption isotherm curve, and (b) is a pore size distribution curve.

[0025] Figure 4 The XRD (X-ray diffraction) pattern of the porous cobalt-antimony alloy negative electrode material prepared in the present invention;

[0026] Figure 5 This is a first charge and discharge curve diagram of the porous cobalt-antimony alloy negative electrode material prepared in the present invention;

[0027] Figure 6 This is a rate performance diagram of the porous cobalt-antimony alloy negative electrode material prepared in the present invention;

[0028] Figure 7 This is a 1C cycle performance diagram of the porous cobalt-antimony alloy negative electrode material prepared in the present invention. DETAILED DESCRIPTION

[0029] The following describes a porous cobalt-antimony alloy negative electrode material, a preparation method thereof, and a battery in the present application in conjunction with embodiments.

[0030] However, the present application may be exemplified in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the scope of the application to those skilled in the art.

[0031] The inventors' research has revealed that prior art methods for preparing M-Sb materials (where M is a metal such as Fe (iron) or Co (cobalt)) by reducing metallic Sb to nanometer size and then combining it with other metals can significantly alleviate the volume expansion problem of metallic Sb, thereby improving its cycling stability. Furthermore, loading the nanosized M-Sb onto a carbon material can prevent Sb reagglomeration while improving its electronic conductivity. Therefore, preparing M-Sb@carbon composites is an effective means of improving the electrochemical performance of Sb.

[0032] However, conventional metal-carbon composite synthesis methods cannot effectively control the particle size of metal particles and make it difficult to evenly distribute the metal particles within the carbon network. Therefore, they can only alleviate the volume expansion problem to a certain extent, with limited improvement in the cycling stability of the electrode material. For example, in the patent application number CN101036947A, entitled "A Method for Preparing a High-Capacity Co / Sb Alloy Lithium-Ion Battery Anode Material," cobalt and antimony oxides are metered according to the ratio of Co to Sb in the resulting alloy composite. An appropriate amount of activated carbon or carbon black is then added as a reducing agent. The resulting mixture is then mixed and heated at a rate of 2-30°C / min to a desired temperature of 750-1000°C in a flowing atmosphere of argon, nitrogen, or argon or nitrogen containing 5-10 vol% H2. The mixture is then held at this temperature for 1-6 hours, followed by programmed temperature cooling or furnace cooling to room temperature. The Co / Sb alloy particles prepared by high-temperature sintering in this patent are large and difficult to evenly disperse, which is detrimental to electrochemical performance. For example, in the patent "Application No.: KR20160028192A, Patent Name: Method for Manufacturing Co-Sb Intermetallic Compound / Carbon Nanocomposite Material by Using Disproportionation Reaction", a cobalt-antimony intermetallic compound / carbon nanocomposite material is prepared by disproportionation reaction. The method includes the following steps: (a) preparing a Co-Sb intermetallic compound by using Co powder and Sb powder; (b) manufacturing a Co-Sb intermetallic compound / carbon nanocomposite material comprising a Co-Sb intermetallic compound, amorphous Sb (a-Sb) and carbon by reacting the Co-Sb intermetallic compound with carbon (C).

[0033] In addition, the structural characteristics of M-Sb, such as particle size, distribution, position, composition, and interaction with the carbon framework, are also important in controlling the electrochemical performance. Furthermore, the properties of carbon also have a significant impact on the performance of Sb, such as the degree of graphitization of carbon, the specific surface area, pore volume, pore size distribution of carbon, and the interaction between carbon and M-Sb.

[0034] Based on this, how to evenly distribute the alloy into the carbon network to suppress the volume change of metallic Sb at the root remains a severe challenge facing high-performance Sb anodes.

[0035] The present invention provides a solution that can fundamentally solve the expansion of metal Sb, as follows:

[0036] An embodiment of the first aspect of the present invention provides a method for preparing a porous cobalt-antimony alloy negative electrode material, the preparation method comprising the following steps:

[0037] Step 1: Encourage Co 3+ and Sb 3+ Carrying out complexation reaction with chelating resin to obtain a complex;

[0038] Step 2: Fully mix the catalyst and the complex to obtain a precursor, then calcine the precursor under protective gas, and wash with water after calcination to obtain a porous cobalt-antimony alloy negative electrode material; wherein the catalyst includes Na + Substances and K-containing + substance.

[0039] In the present invention, firstly, Co and Sb are uniformly coordinated and complexed in the chelate resin at the atomic level, and the metals can be evenly distributed in the carbon network of the carbon composite material after calcination. Secondly, the catalyst selected during calcination includes Na + Substances and K-containing + In the process of high temperature, sodium is reduced to form an alloy with Co-Sb. Then, because Co-Sb is insoluble in water while sodium is soluble in water (i.e., metallic sodium can react with water), the Na metal in the alloy is washed out, leaving pores in the alloy and finally forming a porous Co-Sb alloy. This reserves effective space for the expansion of the Co-Sb alloy, thereby suppressing the volume change of metallic Sb from the root.

[0040] In some embodiments, the Na in the catalyst + and K + The molar ratio is 1:9 to 9:1. In the present invention, this molar ratio ensures that the catalyst must include Na + The porous cobalt-antimony alloy is then washed away during rinsing after calcination, removing not only the Na in the alloy but also the remaining K- and Na-containing substances (i.e., those located within the graphene). This ultimately forms a nanoscale porous Co-Sb alloy uniformly distributed throughout the hierarchically porous three-dimensional graphene composite material (i.e., a porous cobalt-antimony alloy anode material, hereinafter referred to as CS@C).

[0041] In some embodiments, Na + The substance is any one of sodium oxide, sodium peroxide, sodium hydroxide and sodium-containing inorganic salts. Preferably, the sodium-containing inorganic salt can be any one of Na2CO3, NaCl, Na2SO4, NaHCO3, NaNO3 and Na3PO4; the K-containing + The substance is any one of potassium oxide, potassium peroxide, potassium hydroxide and potassium-containing inorganic salts. Preferably, the potassium-containing inorganic salt can be any one of K2CO3, KCl, K2SO4, KHCO3, KNO3 and K3PO4.

[0042] In addition, the catalyst in the present invention also acts as an activator, containing Na +Taking Na2CO3 and potassium-containing substance K2CO3 as examples, the catalyst in the present invention is described as both a catalyst and an activator during calcination (carbonization process). At high temperature, Na2CO3 and K2CO3 will decompose to generate Na2O, K2O, Na-containing substances and K-containing substances. These Na / K-containing compounds will undergo redox reactions with carbon to generate pores. In addition, the metal Na and metal K generated by the redox reaction will be embedded in the carbon lattice, causing the carbon lattice to expand, thereby generating a developed pore structure after washing with water, and this role is that of an activator. At the same time, the metal Na and metal K will also guide the carbon lattice from being unordered to being ordered, thereby facilitating the graphitization of carbon, and thus play the role of a catalyst.

[0043] In some embodiments, Co 3+ and Sb 3+ The molar ratio is 1:9 to 3:7. In the present invention, since Sb is an active component, it can improve the specific capacity, and Co is an inactive component, which mainly stabilizes the material structure. 3+ and Sb 3+ When the molar ratio of Co is 1:9 to 3:7, on the one hand, it can avoid that too little Co cannot improve the stability of the negative electrode material, and on the other hand, it can also avoid that too much Co causes the specific capacity of the negative electrode material to decrease. 3+ Derived from cobalt salts, Sb 3+ Derived from antimony salts.

[0044] Further preferably, the cobalt salt can be any one of CoCl3, Co(NO3)3 and Co2(SO4)3, and the antimony salt can be any one of SbCl3, Sb(NO3)3 and Sb2(SO4)3. In the present embodiment, during the complex reaction, the cobalt salt and the antimony salt are usually dissolved in a solvent (such as ethanol) and then subjected to a complex reaction with a chelating resin. Therefore, after the complex reaction is completed, it is usually necessary to heat and remove the solvent in the complex. The heating temperature varies depending on the solvent. For example, when ethanol is selected as the solvent, the ethanol can be removed at 80°C.

[0045] In certain embodiments, the chelate resin is an iminodiacetic acid type chelate resin. In the present invention, a chelate resin is a high molecular compound that can selectively chelate specific metal ions in the form of an ionic bond or a coordinate bond from a solution containing metal ions. The iminodiacetic acid type chelate resin is a skeleton with a cross-linked polymer (such as styrene / divinylbenzene resin) connected with a special functional group (such as a carboxyl group, an imino group etc.). And Co and Sb are present in the solution with a +3 valence state during the preparation process of the present invention, and more easily form a complex with the iminodiacetic acid type chelate resin, realizing atomic level dispersion. Preferably, the iminodiacetic acid type chelate resin is a CR11 type chelate resin.

[0046] In addition, in this embodiment, the mass ratio of the total mass of the cobalt salt and the antimony salt to the mass of the chelating resin is 1:(1-4). This mass ratio allows the Co-Sb alloy in the porous cobalt-antimony alloy negative electrode material to be uniformly dispersed in the carbon (i.e., graphene) formed by carbonization of the chelating resin. It also prevents the spontaneous agglomeration and growth of the Co-Sb alloy particles when the total mass of the cobalt salt and the antimony salt is excessive. It also prevents the excessive proportion of carbon (i.e., graphene) in the porous cobalt-antimony alloy negative electrode material formed when the mass of the chelating resin is excessive, which could lead to a decrease in the specific capacity of the negative electrode material.

[0047] In some embodiments, the calcination conditions are: a calcination temperature of 500-1200°C and a calcination time of 5 min-10 h. This temperature range ensures the formation of the porous cobalt-antimony alloy negative electrode material, avoids the calcination temperature being lower than 500°C, which may result in incomplete carbonization of the chelating resin, and also avoids the Na + and K + It cannot be fully restored and perform the corresponding functions.

[0048] In some embodiments, the protective gas is argon. In practice, the protective gas may also be other gases that do not participate in the roasting reaction.

[0049] An embodiment of the second aspect of the present invention provides a porous cobalt-antimony alloy negative electrode material, which is prepared by the method described in the embodiment of the first aspect. The porous cobalt-antimony alloy negative electrode material in this embodiment includes a carrier and a porous cobalt-antimony alloy supported on the carrier, wherein the carrier is graphene, which is formed by carbonizing a chelate resin and is porous, and the porous cobalt-antimony alloy is also porous.

[0050] An embodiment of the third aspect of the present invention provides a battery, which includes the porous cobalt-antimony alloy negative electrode material of the embodiment of the second aspect as a negative electrode.

[0051] Example

[0052] The technical solution of the present invention will be further explained below through specific embodiments.

[0053] Example 1

[0054] A method for preparing a porous cobalt-antimony alloy negative electrode material comprises the following steps:

[0055] Step 1: Mix 1g of CoCl3·6H2O and SbCl3 (Co 3+ and Sb 3+ The molar ratio of 1:5) was dissolved in 20 mL of ethanol to form a clear solution, and 2 g of CR11 chelating resin was added to the solution. 3+ and Sb 3+The complex reaction is carried out at room temperature with stirring to form a complex, and the ethanol is removed at 80°C. After the complex reaction is completed, the complex is dried to obtain a dried complex.

[0056] Step 2: The dried complex from Step 1 was mixed with 10 g of a mixture of potassium carbonate and sodium carbonate (sodium carbonate:potassium carbonate molar ratio of 3:7) and ball-milled to obtain a precursor. The precursor was calcined at 500°C in an argon atmosphere for 60 min. After calcination, the precursor was cooled and rinsed with deionized water until neutral. Finally, the product CS@C was obtained by vacuum drying.

[0057] Example 2

[0058] A method for preparing a porous cobalt-antimony alloy negative electrode material comprises the following steps:

[0059] Step 1: Mix 1g of CoCl3·6H2O and SbCl3 (Co 3+ and Sb 3+ The molar ratio of 1:9) was dissolved in 20 mL of ethanol to form a clear solution, and 1 g of CR11 chelating resin was added to the solution. 3+ and Sb 3+ The complex reaction is carried out at room temperature with stirring to form a complex, and the ethanol is removed at 80°C. After the complex reaction is completed, the complex is dried to obtain a dried complex.

[0060] Step 2: The dried complex from Step 1 was mixed with 10 g of a mixture of potassium carbonate and sodium carbonate (sodium carbonate:potassium carbonate molar ratio of 1:9) and ball-milled to obtain a precursor. The precursor was calcined at 800°C in an argon atmosphere for 10 h. After calcination, the precursor was cooled and rinsed with deionized water until neutral. Finally, the product CS@C was obtained by vacuum drying.

[0061] Example 3

[0062] A method for preparing a porous cobalt-antimony alloy negative electrode material comprises the following steps:

[0063] Step 1: Mix 1g of CoCl3·6H2O and SbCl3 (Co 3+ and Sb 3+ The molar ratio of 3:7) was dissolved in 20 mL of ethanol to form a clear solution, and 4 g of CR11 chelating resin was added to the solution. 3+ and Sb 3+ The complex reaction is carried out at room temperature with stirring to form a complex, and the ethanol is removed at 80°C. After the complex reaction is completed, the complex is dried to obtain a dried complex.

[0064] Step 2: The dried complex from Step 1 was mixed with 10 g of a mixture of potassium carbonate and sodium carbonate (sodium carbonate:potassium carbonate molar ratio of 9:1) and ball-milled to obtain a precursor. The precursor was calcined at 1200°C in an argon atmosphere for 5 minutes. After calcination, the precursor was cooled and rinsed with deionized water until neutral. Finally, the product CS@C was obtained by vacuum drying.

[0065] Comparative Example 1

[0066] A method for preparing an antimony alloy negative electrode material comprises the following steps:

[0067] Step 1: 2 g of CR11 chelating resin was mixed with 10 g of a mixture of potassium carbonate and sodium carbonate (sodium carbonate: potassium carbonate molar ratio of 3:7), ball-milled, and calcined at 500 °C in an argon atmosphere for 5 min. The mixture was then centrifuged and washed with deionized water and dried to obtain a three-dimensional graphene structure (HPGC).

[0068] Step 2: Disperse HPGC in a mixture containing 1g of CoCl3·6H2O and SbCl3 (Co 3+ :Sb 3+ 1 g of sodium borohydride was added to 20 mL of ethanol (with a molar ratio of 1:5) to reduce antimony in situ in the three-dimensional porous graphene. The CS / C composite material was obtained by filtration and washing.

[0069] Comparative Example 2

[0070] The preparation method of the antimony alloy negative electrode material in this embodiment is the same as that in Comparative Example 1, except that: in step 2, the three-dimensional structured graphene is directly mixed with metal cobalt and metal antimony (the molar ratio of metal Co to metal Sb is 1:5) and then ball milled to obtain the CS-C composite material.

[0071] Comparative Example 3

[0072] The preparation method of the antimony alloy negative electrode material in this embodiment is the same as that in Example 1, except that sodium carbonate is replaced with potassium carbonate in the same molar amount.

[0073] Comparative Example 4

[0074] The preparation method of the antimony alloy negative electrode material in this embodiment is the same as that in Example 1, except that cobalt chloride is replaced by nickel chloride in the same molar amount.

[0075] Comparative Example 5

[0076] The preparation method of the antimony alloy negative electrode material in this embodiment is the same as that in Example 1, except that CoCl 3 ·6H 2 O is not added.

[0077] Test analysis:

[0078] 1. Morphology and structure test analysis

[0079] 1. The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to TEM (transmission electron microscopy) analysis. The test results are detailed in Figure 1 and Figure 2 .in, Figure 1 This is a macroscopic TEM (transmission electron microscope) image of the porous cobalt-antimony alloy negative electrode material prepared in the present invention. Figure 2 This is a microscopic TEM (transmission electron microscope) image of the porous cobalt-antimony alloy negative electrode material prepared in the present invention.

[0080] The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to BET analysis. The test results are detailed in Figure 3 , Figure 3 The BET (specific surface area) test results of the porous cobalt-antimony alloy negative electrode material prepared in the present invention are shown in FIG. (a) is an adsorption isotherm curve, and (b) is a pore size distribution curve.

[0081] First, from Figure 1 It can be seen that the large curved flakes in the figure are graphite structures with pores in the middle, indicating that they are porous graphene. It can also be seen that the Co-Sb alloy is evenly distributed in the porous graphene; and, through Figure 3 The BET test results further show that the porous cobalt-antimony alloy negative electrode material prepared in Example 1 has a porous structure, especially typical micropores of 1-2 nm and macropores of 10-100 nm.

[0082] in addition, Figure 2 The lattice fringes of the Co-Sb alloy are shown in the figure, and it can be seen that the Co-Sb alloy is uniformly distributed in the graphene at the nanoscale.

[0083] 2. The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to XRD (X-ray diffraction) analysis. The test results are detailed in Figure 4 ;in, Figure 4 This is the XRD (X-ray diffraction) pattern of the porous cobalt-antimony alloy negative electrode material prepared in the present invention.

[0084] from Figure 4 It can be seen that characteristic peaks of Co-Sb alloy appear at 32°, 43° and 46°, which means that the present invention has successfully prepared a porous cobalt-antimony alloy negative electrode material.

[0085] 2. Performance Testing

[0086] 1. The negative electrode materials prepared in the examples and comparative examples were tested for their initial coulombic efficiency, 1C specific capacity, and 1C capacity retention rate. The test results are shown in Table 1.

[0087] Table 1. Negative electrode material performance test table

[0088]

[0089] As can be seen from Table 1, the porous cobalt-antimony alloy negative electrode material prepared in the present invention has excellent first coulombic efficiency, 1C specific capacity and 1C capacity retention rate.

[0090] And it can be seen from Table 1 that compared with Example 1, Comparative Example 1 adopts the preparation method of "first preparing HPGC, then in-situ depositing Co-Sb alloy therein and reducing it, thereby achieving uniform dispersion of Co-Sb alloy" to obtain the negative electrode material. Since it is not formed during the in-situ carbonization process, it lacks binding force with the carbon network, resulting in a lower first efficiency, and similarly leads to poor cycle performance.

[0091] As can be seen from Table 1, the negative electrode material prepared by physical mixing in Comparative Example 2 has poor first efficiency and cycle performance. The reasons are: first, the Co-Sb alloy is unevenly distributed in graphene; second, the Co-Sb alloy has weak adhesion on HPGC.

[0092] As can be seen from Table 1, when comparative example 3 does not use sodium carbonate (i.e., lacks sodium-containing substances), it results in a lack of activator and catalyst during roasting, and the antimony alloy negative electrode material formed lacks reserved expansion space, which in turn leads to its low first efficiency and similarly poor cycle.

[0093] It can be seen from Table 1 that in Comparative Example 4, when Co is replaced by other metals, the first effect and cycle of the negative electrode material prepared are weakened. The reason is that Co has the function of stabilizing the material structure, so there is a strong force between the formed Co-C-Sb. When Co is replaced by other metals, the stability of the negative electrode material will be reduced, and the first effect and cycle of the prepared negative electrode material will be weakened.

[0094] As can be seen from Table 1, in Comparative Example 5, no Co was added. 3+ When the substance is not used, the cycle and first efficiency of the negative electrode material prepared are poor. The reason is that Co has the function of stabilizing the material structure. The lack of Co will lead to the reduction of the stability of the negative electrode material.

[0095] 2. The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to the first charge and discharge test analysis. The test results are detailed in Figure 5 ;in, Figure 5 This is the first charge and discharge curve of the porous cobalt-antimony alloy negative electrode material prepared in the present invention.

[0096] from Figure 5It can be seen from the figure that the porous cobalt-antimony alloy negative electrode material CS@C prepared in the present invention has high specific capacity and coulombic efficiency.

[0097] 3. The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to rate performance test analysis. The test results are detailed in Figure 6 ;in, Figure 6 This is a rate performance diagram of the porous cobalt-antimony alloy negative electrode material prepared in the present invention.

[0098] from Figure 6 It can be seen from the figure that the porous cobalt-antimony alloy negative electrode material CS@C prepared in the present invention has good rate characteristics.

[0099] 4. The porous cobalt-antimony alloy negative electrode material CS@C prepared in Example 1 was subjected to 1C cycle performance test analysis. The test results are detailed in Figure 7 ;in, Figure 7 This is a 1C cycle performance diagram of the porous cobalt-antimony alloy negative electrode material prepared in the present invention.

[0100] from Figure 7 It can be seen from the figure that the porous cobalt-antimony alloy negative electrode material CS@C prepared in the present invention has good cycle stability.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A porous cobalt-antimony alloy negative electrode material, characterized in that: The porous cobalt-antimony alloy negative electrode material is a porous Co-Sb alloy uniformly distributed in a multi-level porous three-dimensional graphene structure; The preparation of the porous cobalt-antimony alloy negative electrode material comprises the following steps: Step 1: Encourage Co 3+ and Sb 3+ Carrying out complexation reaction with chelating resin to obtain a complex; Step 2: fully mixing the catalyst and the complex to obtain a precursor, then calcining the precursor under a protective gas, and washing with water after calcination to obtain a porous cobalt-antimony alloy negative electrode material; Wherein, the catalyst includes Na + Substances and K-containing + Substance; the chelate resin is an iminodiacetic acid type chelate resin; Na + During the roasting process, reduction is carried out to form an alloy with Co-Sb. The fact that Co-Sb is insoluble in water while sodium is soluble in water is used to wash out the Na metal in the alloy, leaving pores in the alloy to form a porous Co-Sb alloy. When washed with water after roasting, the K and Na-containing substances in the roasted graphene are washed away, forming a multi-level porous three-dimensional structure graphene.

2. The porous cobalt-antimony alloy negative electrode material according to claim 1, characterized in that: The Co 3+ and Sb 3+ The molar ratio is 1:9~3:

7.

3. The porous cobalt-antimony alloy negative electrode material according to claim 2, characterized in that: The Co 3+ Derived from cobalt salt, the Sb 3+ Derived from antimony salts; The mass ratio of the total mass of the cobalt salt and the antimony salt to the chelating resin is 1:(1-4).

4. The porous cobalt-antimony alloy negative electrode material according to claim 1, characterized in that: The Na in the catalyst + and K + The molar ratio is 1:9~9:

1.

5. The porous cobalt-antimony alloy negative electrode material according to claim 4, characterized in that: The Na-containing + The substance is any one of sodium oxide, sodium peroxide, sodium hydroxide and sodium-containing inorganic salts; The K-containing + The substance is any one of potassium oxide, potassium peroxide, potassium hydroxide and potassium-containing inorganic salts.

6. The porous cobalt-antimony alloy negative electrode material according to claim 1, characterized in that: The calcination conditions are: calcination temperature of 500-1200°C, and calcination time of 5 min-10 h.

7. The porous cobalt-antimony alloy negative electrode material according to claim 1, characterized in that: The protective gas is argon.

8. A battery, characterized in that: The battery comprises the porous cobalt-antimony alloy negative electrode material according to any one of claims 1 to 7 as a negative electrode.

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