Copper sulfide / cobalt tetrasulfide hybrid nanocages as lithium metal anode materials
By preparing the lithium metal negative electrode material of copper sulfide/tricobalt sulfide hybrid nanocage, the problems of poor conductivity and large volume changes of the negative electrode material of lithium metal battery are solved, and the electrochemical performance improvement of high capacity and long cycle life is achieved.
Patent Information
- Application Number
- CN202211396917.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-09
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2042-11-09
AI Technical Summary
The negative electrode materials of existing lithium metal batteries have poor conductivity and large volume changes during the electrochemical reaction, resulting in limited reaction rate and cycling performance.
A lithium metal negative electrode material using copper sulfide/tricobalt tetrasulfide hybrid nanocage was used to form a mesh cubic nano hollow structure by stacking CuS nanosheets and Co3S4 nanosheets. Cu2O was used as a template and a corrosion deposition and vulcanization path were used to prepare CuS/Co3S4 hybrid nanostructures.
The electrochemical performance of lithium metal batteries is improved, showing high capacity, outstanding rate performance and long cycle life.
Smart Images
Figure CN115863560B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of lithium metal batteries, and in particular to lithium metal negative electrode materials of copper sulfide / cobalt tetrasulfide hybrid nanocages. Background Art
[0002] As the demand for advanced portable electronics and electric vehicles continues to increase, the demand for high energy density electrochemical storage devices is also increasing. Lithium metal batteries have a low electrode potential (3.04 V relative to standard hydrogen electrode) and a high theoretical specific capacity (3860 mAh g -1 ) and has attracted increasing attention. Lithium metal batteries can use metallic lithium as the anode, thus providing the opportunity to use lithium-free materials as the cathode. Due to their high capacity and good electrochemical reversibility, various metal sulfides, such as CoS x 、CuS x 、SnS x 、FeS x While some nanostructured electrodes have been reported for use in lithium metal batteries, their poor conductivity and large volume changes during electrochemical reactions limit reaction rates and cycling performance. Rational nanostructure design and carbon modification are two effective approaches to address these issues and enhance electrochemical performance. Due to the synergistic effects of different components, constructing hybrid nanostructured electrodes is considered an effective strategy to enhance lithium storage performance. Summary of the Invention
[0003] In view of this, the present application provides a lithium metal negative electrode material of copper sulfide / cobalt tetrasulfide hybrid nanocage, which can improve the electrochemical performance.
[0004] In a first aspect, the present application provides a lithium metal negative electrode material of a copper sulfide / cobalt tetrasulfide hybrid nanocage, the morphology of which presents a network cubic nano hollow structure and is composed of a stack of CuS nanosheets and Co3S4 nanosheets.
[0005] In a second aspect, the present application provides a method for preparing the above-mentioned lithium metal negative electrode material, comprising the following steps:
[0006] A. dispersing Cu2O and a cobalt source in a mixed solution of deionized water and ethanol to obtain solution a;
[0007] B. adding polyvinylpyrrolidone (PVP) to the solution a to react to obtain a solution b;
[0008] C. adding lithium thiosulfate pentahydrate solution to the solution b to react to obtain solution c;
[0009] D. Add lithium sulfide solution to solution c to react, and then centrifuge to obtain a CuS / Co(OH)2 hybrid structure;
[0010] E. Dispersing the CuS / Co(OH)2 hybrid structure in a mixed solution of deionized water and ethanol, adding lithium thiosulfate pentahydrate to react, and hydrothermally reacting the collected precipitate product with thioacetamide in an ethanol solution to obtain a CuS / Co3S4 hybrid nanocage material.
[0011] Suitably but not limiting, in step A:
[0012] The mass ratio of the Cu2O to the cobalt source is 10:3-6;
[0013] Preferably, the cobalt source is one of cobalt chloride, cobalt nitrate and cobalt sulfate;
[0014] Preferably, the volume ratio of deionized water to ethanol in the mixed solution of deionized water and ethanol is 1:1.
[0015] Suitable but not limited to, in step B:
[0016] The mass of the polyvinyl pyrrolidone (PVP) is 1-6 g, and the volume of solution a is 1 ml.
[0017] Suitably but not limiting, in step C:
[0018] The volume ratio of the anhydrous lithium thiosulfate solution to the solution a is 1 to 2:5;
[0019] Preferably, the concentration of the lithium thiosulfate pentahydrate solution is 0.1-1M.
[0020] Suitable but not limiting, in said step D:
[0021] The volume ratio of the lithium sulfide solution to the solution c is 1:5-10;
[0022] Preferably, the concentration of the lithium sulfide solution is in the range of 0.01 to 0.1M.
[0023] Suitably but not limiting, in step E:
[0024] The volume ratio of the anhydrous lithium thiosulfate solution to the solution a is 1 to 2:5, and the concentration of the lithium thiosulfate pentahydrate solution is 0.1 to 1 M;
[0025] Preferably, the mass ratio of thioacetamide to Cu2O is 9:20.
[0026] Suitable but not limiting, in step E: the temperature of the hydrothermal reaction is 105-115° C., and the reaction time is 1.5-2.5 h.
[0027] In a third aspect, the present application provides a lithium metal battery having the lithium metal negative electrode material as described above.
[0028] Conventional technology known to those skilled in the art is that the aforementioned lithium metal battery negative electrode material is coated to form a negative electrode sheet. The negative electrode sheet comprises a substrate and a slurry coated on the substrate. The slurry is composed of an active material, conductive carbon black, and a binder.
[0029] Here, the substrate is single-gloss copper foil, double-gloss copper foil or aluminum foil.
[0030] Here, the conductive carbon black is super carbon black (Super P Li).
[0031] Here, the binder is polyvinylidene fluoride (PVDF).
[0032] Here, the solvent for the slurry material is N-methylpyrrolidone (NMP).
[0033] Compared with the prior art, the copper sulfide / cobalt tetrasulfide hybrid nanocage lithium metal negative electrode material of the present application has the following beneficial effects:
[0034] (1) This application provides a method for preparing CuS / Co3S4 hybrid nanocage lithium metal anode materials. Using Cu2O as a template, a corrosion deposition and sulfurization process are used to prepare CuS / Co3S4 hybrid nanostructures for the first time. This method is simple and easy to operate, has a short reaction cycle, is environmentally friendly, and is low-cost.
[0035] (2) The CuS / Co3S4 hybrid nanocage lithium metal negative electrode prepared in this application improves the electrochemical performance of the battery, showing high capacity, outstanding rate performance and long cycle life. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.
[0037] Figure 1 a represents a low-magnification field scanning electron microscope (SEM) image of the CuS / Co3S4 hybrid nanocage lithium metal negative electrode active material in this embodiment, with a resolution of 1 μm; Figure 1 b represents a high-magnification scanning electron microscope (SEM) image of the CuS / Co3S4 hybrid nanolithium metal electrode active material in this embodiment, with a resolution of 200 nm;
[0038] Figure 2 The test diagrams of Examples 1-5 are shown, which are cycle curves of lithium metal batteries assembled using CuS / Co3S4 hybrid nano-lithium metal electrode sheets. DETAILED DESCRIPTION
[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.
[0040] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. The reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.
[0041] Example 1
[0042] A. Preparation of CuS / Co3S4 hybrid nanoelectrode active materials
[0043] 1) Weigh a certain amount of Cu2O (200 mg) and a certain amount of cobalt chloride (80 mg) and disperse them in a deionized water / ethanol mixed solution (volume ratio 1:1) and sonicate for 10 minutes; add 1 g of polyvinylpyrrolidone (K30) to the above solution and stir at room temperature for 30 minutes; then add 40 mL of sodium thiosulfate pentahydrate (0.86 M) dropwise to the solution and react for 8 minutes; then add 40 mL of sodium sulfide solution (0.086 M) dropwise and react for 5 minutes before centrifugation to obtain a Cu2O / CuS / Co(OH)2 hybrid structure;
[0044] 2) The above precipitate was redispersed in a deionized water / ethanol mixed solution (volume ratio 1:1), and 40 mL of sodium thiosulfate pentahydrate solution (0.86 M) was added dropwise. After reacting for 2 hours, the mixture was centrifuged and the precipitate was washed multiple times (at least 5 times) with a deionized water / ethanol mixed solution. The precipitate was collected to obtain a CuS / Co(OH)2 structure;
[0045] 3) The above precipitate and thioacetamide (90 mg) were dispersed in an ethanol solution and stirred for 30 minutes. The above solution was transferred to a reactor for hydrothermal reaction. After reacting at 100°C for 2 hours, the mixture was collected by centrifugation and finally washed with a deionized water / ethanol mixed solution. The final precipitate was dried in an oven to obtain CuS / Co3S4 hybrid nanomaterials.
[0046] B. Preparation of CuS / Co3S4 hybrid nanoelectrode
[0047] A certain amount of polyvinylidene fluoride (PVDF) was weighed and dispersed in an N-methylpyrrolidone solution. A certain amount of CuS / Co3S4 hybrid nanomaterial and conductive carbon black (Super P Li) were weighed and ground. After grinding, the mixture was added to the above solution and stirred for a certain period of time to obtain a uniformly dispersed slurry. The slurry was coated on a single-layer copper foil, dried at 80°C for 6 hours, and transferred to a vacuum oven for further drying for 12 hours. The slurry was cut into discs with a diameter of 10 mm, and the coating surface density was about 1.1 mg cm -2 .
[0048] Assemble lithium metal batteries and test the lithium metal batteries using the electrode at room temperature at 0.5A·g -1 The charge and discharge cycle curve under current density is set to 1.2-3.0V.
[0049] Example 2
[0050] A. Preparation of CuS / Co3S4 hybrid nanoelectrode active materials
[0051] 1) Weigh a certain amount of Cu2O (200 mg) and a certain amount of cobalt chloride (120 mg) and disperse them in a deionized water / ethanol mixed solution (volume ratio 1:1) and sonicate for 10 minutes; add 1 g of polyvinylpyrrolidone (K30) to the above solution and stir at room temperature for 30 minutes; then add 40 mL of sodium thiosulfate pentahydrate (0.86 M) dropwise to the solution and react for 8 minutes; then add 40 mL of sodium sulfide solution (0.086 M) dropwise and react for 5 minutes before centrifugation to obtain a Cu2O / CuS / Co(OH)2 hybrid structure;
[0052] 2) The above precipitate was redispersed in a deionized water / ethanol mixed solution (volume ratio 1:1), and 40 mL of sodium thiosulfate pentahydrate solution (0.86 M) was added dropwise. After reacting for 2 hours, the mixture was centrifuged and the precipitate was washed multiple times (at least 5 times) with a deionized water / ethanol mixed solution. The precipitate was collected to obtain a CuS / Co(OH)2 structure;
[0053] 3) The above precipitate and thioacetamide (90 mg) were dispersed in an ethanol solution and stirred for 30 minutes. The above solution was transferred to a reactor for hydrothermal reaction. After reacting at 100°C for 2 hours, the mixture was collected by centrifugation and finally washed with a deionized water / ethanol mixed solution. The final precipitate was dried in an oven to obtain CuS / Co3S4 hybrid nanomaterials.
[0054] B. Preparation of CuS / Co3S4 hybrid nanoelectrode
[0055] A certain amount of polyvinylidene fluoride (PVDF) was weighed and dispersed in an N-methylpyrrolidone solution. A certain amount of CuS / Co3S4 hybrid nanomaterial and conductive carbon black (Super P Li) were weighed and ground. After grinding, the mixture was added to the above solution and stirred for a certain period of time to obtain a uniformly dispersed slurry. The slurry was coated on a single-layer copper foil, dried at 80°C for 6 hours, and transferred to a vacuum oven for further drying for 12 hours. The slurry was cut into discs with a diameter of 10 mm, and the coating surface density was about 1.1 mg cm -2 .
[0056] Assemble lithium metal batteries and test the lithium metal batteries using the electrode at room temperature at 0.5A g -1 The charge and discharge cycle curve under current density is set to 1.2-3.0V.
[0057] Example 3
[0058] A. Preparation of CuS / Co3S4 hybrid nanoelectrode active materials
[0059] 1) Weigh a certain amount of Cu2O (200 mg) and a certain amount of cobalt chloride (80 mg) and disperse them in a deionized water / ethanol mixed solution (volume ratio 1:1) and sonicate for 10 minutes; add 1 g of polyvinylpyrrolidone (K30) to the above solution and stir at room temperature for 30 minutes; then add 60 mL of sodium thiosulfate pentahydrate (0.86 M) dropwise to the solution and react for 8 minutes; then add 40 mL of sodium sulfide solution (0.086 M) dropwise and react for 5 minutes before centrifugation to obtain a Cu2O / CuS / Co(OH)2 hybrid structure;
[0060] 2) The above precipitate was redispersed in a deionized water / ethanol mixed solution (volume ratio 1:1), and 60 mL of sodium thiosulfate pentahydrate solution (0.86 M) was added dropwise. After reacting for 2 hours, the mixture was centrifuged and the precipitate was washed multiple times (at least 5 times) with a deionized water / ethanol mixed solution. The precipitate was collected to obtain a CuS / Co(OH)2 structure;
[0061] 3) The above precipitate and thioacetamide (90 mg) were dispersed in an ethanol solution and stirred for 30 minutes. The above solution was transferred to a reactor for hydrothermal reaction. After reacting at 100°C for 2 hours, the mixture was collected by centrifugation and finally washed with a deionized water / ethanol mixed solution. The final precipitate was dried in an oven to obtain CuS / Co3S4 hybrid nanomaterials.
[0062] B. Preparation of CuS / Co3S4 hybrid nanoelectrode
[0063] A certain amount of polyvinylidene fluoride (PVDF) was weighed and dispersed in an N-methylpyrrolidone solution. A certain amount of CuS / Co3S4 hybrid nanomaterial and conductive carbon black (Super P Li) were weighed and ground. After grinding, the mixture was added to the above solution and stirred for a certain period of time to obtain a uniformly dispersed slurry. The slurry was coated on a single-layer copper foil, dried at 80°C for 6 hours, and transferred to a vacuum oven for further drying for 12 hours. The slurry was cut into discs with a diameter of 10 mm, and the coating surface density was about 1.1 mg cm -2 .
[0064] Assemble lithium metal batteries and test the lithium metal batteries using the electrode at room temperature at 0.5A g -1 The charge and discharge cycle curve under current density is set to 1.2-3.0V.
[0065] Example 4
[0066] A. Preparation of CuS / Co3S4 hybrid nanoelectrode active materials
[0067] 1) Weigh a certain amount of Cu2O (200 mg) and a certain amount of cobalt chloride (80 mg) and disperse them in a deionized water / ethanol mixed solution (volume ratio 1:1) and sonicate for 10 minutes; add 1 g of polyvinylpyrrolidone (K30) to the above solution and stir at room temperature for 30 minutes; then add 80 mL of sodium thiosulfate pentahydrate (0.86 M) dropwise to the solution and react for 8 minutes; then add 40 mL of sodium sulfide solution (0.086 M) dropwise and react for 5 minutes before centrifugation to obtain a Cu2O / CuS / Co(OH)2 hybrid structure;
[0068] 2) The above precipitate was redispersed in a deionized water / ethanol mixed solution (volume ratio 1:1), and 80 mL of sodium thiosulfate pentahydrate solution (0.86 M) was added dropwise. After reacting for 2 hours, the mixture was centrifuged and the precipitate was washed multiple times (at least 5 times) with a deionized water / ethanol mixed solution. The precipitate was collected to obtain a CuS / Co(OH)2 structure;
[0069] 3) The above precipitate and thioacetamide (90 mg) were dispersed in an ethanol solution and stirred for 30 minutes. The above solution was transferred to a reactor for hydrothermal reaction. After reacting at 100°C for 2 hours, the mixture was collected by centrifugation and finally washed with a deionized water / ethanol mixed solution. The final precipitate was dried in an oven to obtain CuS / Co3S4 hybrid nanomaterials.
[0070] B. Preparation of CuS / Co3S4 hybrid nanoelectrode
[0071] A certain amount of polyvinylidene fluoride (PVDF) was weighed and dispersed in an N-methylpyrrolidone solution. A certain amount of CuS / Co3S4 hybrid nanomaterial and conductive carbon black (Super P Li) were weighed and ground. After grinding, the mixture was added to the above solution and stirred for a certain period of time to obtain a uniformly dispersed slurry. The slurry was coated on a single-layer copper foil, dried at 80°C for 6 hours, and transferred to a vacuum oven for further drying for 12 hours. The slurry was cut into discs with a diameter of 10 mm, and the coating surface density was about 1.1 mg cm -2 .
[0072] Assemble lithium metal batteries and test the lithium metal batteries using the electrode at room temperature at 0.5A g -1 The charge and discharge cycle curve under current density is set to 1.2-3.0V.
[0073] Example 5
[0074] A. Preparation of CuS / Co3S4 hybrid nanoelectrode active materials
[0075] 1) Weigh a certain amount of Cu2O (200 mg) and a certain amount of cobalt chloride (80 mg) and disperse them in a deionized water / ethanol mixed solution (volume ratio 1:1) and sonicate for 10 minutes; add 6 g of polyvinylpyrrolidone (K30) to the above solution and stir at room temperature for 30 minutes; then add 40 mL of sodium thiosulfate pentahydrate (0.86 M) dropwise to the solution and react for 8 minutes; then add 40 mL of sodium sulfide solution (0.086 M) dropwise and react for 5 minutes before centrifugation to obtain a Cu2O / CuS / Co(OH)2 hybrid structure;
[0076] 2) The above precipitate was redispersed in a deionized water / ethanol mixed solution (volume ratio 1:1), and 40 mL of sodium thiosulfate pentahydrate solution (0.86 M) was added dropwise. After reacting for 2 hours, the mixture was centrifuged and the precipitate was washed multiple times (at least 5 times) with a deionized water / ethanol mixed solution. The precipitate was collected to obtain a CuS / Co(OH)2 structure;
[0077] 3) The above precipitate and thioacetamide (90 mg) were dispersed in an ethanol solution and stirred for 30 minutes. The above solution was transferred to a reactor for hydrothermal reaction. After reacting at 100°C for 2 hours, the mixture was collected by centrifugation and finally washed with a deionized water / ethanol mixed solution. The final precipitate was dried in an oven to obtain CuS / Co3S4 hybrid nanomaterials.
[0078] B. Preparation of CuS / Co3S4 hybrid nanoelectrode
[0079] A certain amount of polyvinylidene fluoride (PVDF) was weighed and dispersed in an N-methylpyrrolidone solution. A certain amount of CuS / Co3S4 hybrid nanomaterial and conductive carbon black (Super P Li) were weighed and ground. After grinding, the mixture was added to the above solution and stirred for a certain period of time to obtain a uniformly dispersed slurry. The slurry was coated on a single-layer copper foil, dried at 80°C for 6 hours, and transferred to a vacuum oven for further drying for 12 hours. The slurry was cut into discs with a diameter of 10 mm, and the coating surface density was about 1.1 mg cm -2 .
[0080] Assemble lithium metal batteries and test the lithium metal batteries using the electrode at room temperature at 0.5A g -1 The charge and discharge cycle curve under current density is set to 1.2-3.0V.
[0081] from Figure 1 It can be seen from the high and low magnification scanning electron micrographs of the CuS / Co3S4 hybrid nanolithium metal electrode active materials in a and 1b that the CuS / Co3S4 hybrid nanostructure prepared in the present application has a mesh-like cubic nanohollow structure, the surface of which is composed of CuS and Co3S4 sheets stacked together, and the material size is maintained at about 500 nm and is evenly dispersed.
[0082] from Figure 2 The results of the lithium metal battery cycle test of the CuS / Co3S4 hybrid nano-lithium metal electrode assembly show that the battery capacity in Example 1 reaches 421mAg -1 , stable cycle of about 200 cycles; Example 2 increases the mass of cobalt chloride on the basis of Example 1, and the results show that the capacity is reduced, reaching only 216mAh g -1 In Example 3 and Example 4, the volume of sodium thiosulfate pentahydrate solution was increased in turn on the basis of Example 1. The results showed that the performance of the electrode assembly battery prepared by adding 40mL of sodium thiosulfate pentahydrate solution was the best and the capacity was the highest. However, due to poor stability, there was a tendency of attenuation after 200 cycles. Therefore, in Example 5, the mass of polyvinyl pyrrolidone was increased on the basis of Example 1. It was found that while maintaining a high capacity (407mAh·g -1 ) while being able to stably cycle for more than 500 times.
[0083] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.
Claims
1. A method for preparing a lithium metal negative electrode material of a copper sulfide / cobalt tetrasulfide hybrid nanocage, characterized in that: The following steps are involved: A. dispersing Cu2O and a cobalt source in a mixed solution of deionized water and ethanol to obtain solution a; B. adding polyvinylpyrrolidone (PVP) to the solution a to react to obtain a solution b; C. adding lithium thiosulfate pentahydrate solution to the solution b to react to obtain solution c; D. Add lithium sulfide solution to solution c to react, and then centrifuge to obtain a CuS / Co(OH)2 hybrid structure; E. dispersing the CuS / Co(OH)2 hybrid structure in a mixed solution of deionized water and ethanol, adding lithium thiosulfate pentahydrate to react, and hydrothermally reacting the collected precipitate with thioacetamide in an ethanol solution to obtain a CuS / Co3S4 hybrid nanocage material; The lithium metal negative electrode material has a morphology of a network cubic nano hollow structure and is formed by stacking CuS nanosheets and Co3S4 nanosheets.
2. The method for preparing the lithium metal negative electrode material according to claim 1, wherein: In step A: The mass ratio of the Cu2O to the cobalt source is 10:3-6; The cobalt source is one of cobalt chloride, cobalt nitrate and cobalt sulfate; The volume ratio of deionized water to ethanol in the deionized water and ethanol mixed solution is 1:
1.
3. The method for preparing the lithium metal negative electrode material according to claim 1, wherein: In step B: The mass of the polyvinylpyrrolidone (PVP) is 1-6 g, and the volume of solution a is 1 ml.
4. The method for preparing the lithium metal negative electrode material according to claim 1, wherein: In step C: The volume ratio of the lithium thiosulfate pentahydrate solution to the solution a is 1-2:5; The concentration of the lithium thiosulfate pentahydrate solution is 0.1-1 M.
5. The method for preparing the lithium metal negative electrode material according to claim 1, wherein: In the step D: The volume ratio of the lithium sulfide solution to the solution c is 1:5-10; The concentration range of the lithium sulfide solution is 0.01~0.1 M.
6. The method for preparing the lithium metal negative electrode material according to claim 1, characterized in that: In step E: The volume ratio of the lithium thiosulfate pentahydrate solution to the solution a is 1-2:5, and the concentration of the lithium thiosulfate pentahydrate solution is 0.1-1 M; The mass ratio of the thioacetamide to Cu2O is 9:
20.
7. The method for preparing the lithium metal negative electrode material according to claim 1, characterized in that: In step E: the temperature of the hydrothermal reaction is 105-115° C., and the reaction time is 1.5-2.5 h.
8. A lithium metal battery, characterized in that: A lithium metal negative electrode material prepared by the preparation method according to any one of claims 1 to 7.