CN115241443A - Preparation method of transition metal sulfide/carbon of lithium ion battery negative electrode material - Google Patents

Preparation method of transition metal sulfide/carbon of lithium ion battery negative electrode material Download PDF

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CN115241443A
CN115241443A CN202211025298.2A CN202211025298A CN115241443A CN 115241443 A CN115241443 A CN 115241443A CN 202211025298 A CN202211025298 A CN 202211025298A CN 115241443 A CN115241443 A CN 115241443A
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carbon
lithium ion
ion battery
transition metal
metal sulfide
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闫霄
刘小雨
马昕
顾洪飞
谭春梅
王敏
李彦娟
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Jiangsu Normal University
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/12—Sulfides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/581—Chalcogenides or intercalation compounds thereof
    • H01M4/5815—Sulfides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

The invention discloses a preparation method of transition metal sulfide/carbon of a lithium ion battery cathode material, which comprises the following steps: dispersing metal sulfate, a carbon source and a molten salt medium into certain water, and stirring into a uniform mixed solution; transferring the mixed solution into an evaporating dish, and setting freezing temperature and freezing time for freeze drying; grinding the freeze-dried sample into powder, performing high-temperature heat treatment in a sintering atmosphere, and desalting and drying to obtain the TMS/C composite material with a layered structure. The method has the advantages of no need of an additional sulfur source, green and simple preparation process, low cost, short reaction time, uniform particle size distribution of the prepared material, high purity crystallinity and high electrochemical capacity, and can show excellent electrochemical performance when the material is used as a lithium ion negative electrode material.

Description

Preparation method of transition metal sulfide/carbon of lithium ion battery negative electrode material
Technical Field
The invention belongs to the technical field of lithium ion battery electrode materials, and particularly relates to a preparation method of a transition metal sulfide/carbon of a lithium ion battery cathode material.
Background
Rechargeable lithium ion batteries play an important role in relieving energy crisis and environmental pollution. The cathode material is used as a key component of the battery and has important significance for the development of high-performance batteries. At present, graphite is commercially used as a negative electrode material of a lithium ion battery, and has the advantages of high stability, good conductivity, wide source and the like. But the theoretical capacity is lower and is only 372mAh/g.
Transition metal sulfide M of conversion radical x S y (M = Mn, fe, ni, co and Cu) has higher theoretical capacity which is nearly two times higher than that of a commercial graphite electrode, and the voltage platform is more than 1.0V, so that the formation of lithium dendrites is avoided, and the high safety of the lithium dendrites is ensured. These advantages indicate that the metal sulfide is expected to become the next generation lithium ion battery cathode material. However, the problems of volume change of the transition metal sulfide in the charging and discharging process, poor dissolution and conductivity of lithium polysulfide and the like cause that the cycle performance and rate capability of the transition metal sulfide as a battery negative electrode material are not ideal. Research shows that the metal sulfide and carbon composite material (TMS/C) can improve the electrochemical performance.
The common methods for synthesizing transition metal sulfide/carbon mainly include hydrothermal method, solvothermal method, high-temperature solid-phase method and the like, but the methods are complex in synthesis process, long in time consumption and difficult to control the shape and size of the material.
Disclosure of Invention
The invention aims to provide a preparation method of transition metal sulfide/carbon of a lithium ion battery cathode material, which does not need an additional sulfur source, has the advantages of green and simple preparation process, low cost, short reaction time and easiness in controlling the shape and the size of the material, and the prepared material has uniform particle size distribution, high purity crystallinity and high electrochemical capacity and can show excellent electrochemical performance when being used as a lithium ion cathode material.
In order to achieve the purpose, the invention adopts the technical scheme that: a preparation method of transition metal sulfide/carbon of a lithium ion battery negative electrode material comprises the following steps:
(1) Dispersing metal sulfate, a carbon source and a molten salt medium into certain water, and stirring into a uniform mixed solution;
(2) Transferring the mixed solution into an evaporating dish, and setting freezing temperature and freezing time for freeze drying;
(3) And (3) grinding the sample subjected to freeze drying in the step (2) into powder, performing high-temperature heat treatment in a sintering atmosphere, and desalting and drying to obtain the TMS/C composite material with the laminated structure.
Preferably, in the step (1), the mass ratio of the metal sulfate, the carbon source and the molten salt medium is 1: (0.5-1): (4-6); stirring for 2 hours at normal temperature at the rotating speed of 1000 r/min; the concentration of the metal sulfate in the mixed solution is 0.5mol/L.
Preferably, in the step (1), the metal sulfate is one of ferrous sulfate, cobalt sulfate, copper sulfate, nickel sulfate, stannous sulfate and vanadyl sulfate.
Preferably, in the step (1), the carbon source is one of glucose, citric acid, tartaric acid, phenolic resin and dopamine.
Preferably, in the step (1), the molten salt medium is one or more of sodium chloride, potassium chloride and lithium chloride.
Preferably, in the step (2), the freezing temperature is-50 to-30 ℃, and the freezing time is 12 to 24 hours.
Preferably, in the step (3), the sintering temperature is 800-1000 ℃, and the sintering time is 3-5h;
preferably, in the step (3), the sintering atmosphere is one of nitrogen, argon and a mixed atmosphere of argon/hydrogen.
Further, in the step (3), the desalting and drying process comprises: and putting the sintered sample in an oil bath at the temperature of 60-80 ℃ for desalting for 12-24h, and drying at the temperature of 70-90 ℃ in a vacuum atmosphere for 12-20h.
Compared with the prior art, the invention has the following advantages:
the TMS/C composite material is prepared by using metal sulfate and a carbon source as raw materials and using molten salt as a template through one-step conversion. The method is simpler and universal, and different TMS/C composite materials can be prepared by different metal sulfates; meanwhile, molten salt is used for providing a liquid environment for the template, the ion diffusion speed is remarkably accelerated, and reactants are mixed at a molecular scale, so that the reaction is changed from solid-solid reaction into solid-liquid or liquid-liquid reaction. The method has the advantages of no need of an additional sulfur source, green and simple preparation process, low cost, short reaction time, easiness in controlling the shape, the size and the like of the material, uniform particle size distribution of the prepared material, high purity and crystallinity, and contribution to lithium ion transmission.
Drawings
FIG. 1 is an XRD pattern of a FeS/C composite material prepared according to a first embodiment of the present invention;
FIG. 2 is an SEM image of a FeS/C composite material prepared according to a first embodiment of the invention;
fig. 3 is a charge-discharge cycle curve diagram of a lithium ion battery assembled by the FeS/C composite prepared in the first embodiment of the present invention at a current density of 1C.
FIG. 4 is a graph of rate capability of the FeS/C composite material prepared in the first embodiment of the present invention as a lithium ion battery cathode material.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
Example one
A preparation method of transition metal sulfide/carbon of a lithium ion battery negative electrode material comprises the following steps:
(1) 1g ferrous sulfate and 0.5g glucose were dispersed in 7.19ml water (C (FeSO) 4 ) =0.5 mol/L), and 5g of a mixture of LiCl and KCl (mass ratio between LiCl and KCl 45:55 Stirring to obtain a uniform mixed solution;
(2) Transferring the mixed solution into an evaporation dish, and freeze-drying the mixed solution for 24 hours at a freezing temperature of-40 ℃;
(3) Grinding the sample subjected to freeze drying in the step (2) to powder, performing high-temperature heat treatment in an argon atmosphere, wherein the sintering temperature is 900 ℃, the sintering time is 5h, placing the sintered sample in an oil bath at 80 ℃ for desalting for 12h, and drying in a vacuum atmosphere at 80 ℃ for 15h to obtain the FeS/C composite material with a laminated structure.
The FeS/C composite material prepared in this example was subjected to characterization test, and XRD result in fig. 1 shows that all diffraction peaks are attributed to standard peaks, which proves that pure-phase FeS is obtained. The SEM result of FIG. 2 shows that the FeS/C composite material has a layered structure.
The FeS/C composite material prepared in this example was subjected to electrochemical performance test: uniformly mixing the prepared negative electrode composite material, a conductive agent Super P and a binder polyvinylidene fluoride, fully grinding, mixing with a dispersant N-methyl pyrrolidone to make a sample into a viscous state, coating the sample on a copper foil, drying, and cutting the dried sample into electrode plates with the diameter of 10 mm. The electrode sheet, a 14mm round lithium sheet, a 16mm round Celgard 2400, an electrolyte (1 MLiPF6 dissolved in ethylene carbonate/methyl carbonate/diethyl carbonate v = 1). As can be seen from FIG. 3, at a current density of 1C, the lithium ion battery has an initial specific capacity of 831.5mAh/g, and after 100 cycles, the capacity is maintained at 581.6mAh/g, and the capacity retention rate is as high as 69.9%. As can be seen from FIG. 4, at a current density of 5C, the specific discharge capacity still reaches 402.6mAh/g, and the rate also shows excellent electrochemical performance.
Example two
A preparation method of transition metal sulfide/carbon of a lithium ion battery cathode material comprises the following steps:
(1) 0.5g of cobalt sulfate and 0.5g of glucose were dispersed in 3.55mL of water (C (CoSO) 4 ) =0.5 mol/L), adding 3g NaCl, and stirring to obtain a uniform mixed solution;
(2) Transferring the mixed solution into an evaporation dish, and freeze-drying the mixed solution for 18 hours, wherein the freezing temperature is set to be-30 ℃;
(3) Grinding the sample subjected to freeze drying in the step (2) into powder, performing high-temperature heat treatment in an argon atmosphere, wherein the sintering temperature is 800 ℃, the sintering time is 4h, placing the sintered sample at 60 ℃ for oil bath desalination for 24h, and drying at 70 ℃ for 20h in a vacuum atmosphere to obtain Co with a laminated structure 9 S 8 a/C composite material.
The electrochemical performance of the composite material prepared in this example was tested in the same manner as in example one. The test results are: under the current density of 1C, the initial specific capacity of the lithium ion battery is 844.8mAh/g, after 100 weeks of circulation, the capacity is maintained at 487.2mAh/g, and the capacity retention rate reaches 57.2%. Under the current density of 5C, the specific discharge capacity still reaches 295.1mAh/g, and the multiplying power also shows excellent electrochemical performance.
EXAMPLE III
A preparation method of transition metal sulfide/carbon of a lithium ion battery negative electrode material comprises the following steps:
(1) 1g copper sulfate and 0.6g phenolic resin were dispersed in 12.5mL water (C (CuSO) 4 ) =0.5 mol/L), adding 4g NaCl, stirring at the rotation speed of 1000r/min for 2h at normal temperature, and stirring into a uniform mixed solution;
(2) Transferring the mixed solution into an evaporation dish, and freeze-drying the mixed solution for 12 hours at a freezing temperature of-50 ℃;
(3) Grinding the sample subjected to freeze drying in the step (2) to powder, performing high-temperature heat treatment in an argon atmosphere, wherein the sintering temperature is 1000 ℃, the sintering time is 3h, placing the sintered sample at 70 ℃ for oil bath desalination for 20h, and drying at 90 ℃ for 12h in a vacuum atmosphere to obtain the CuS/C composite material with a laminated structure.
The electrochemical performance of the composite material prepared in this example was tested in the same manner as in example one. The test results are as follows: under the current density of 1C, the lithium ion battery has the initial specific capacity of 1031.5mAh/g, and after 100-week circulation, the capacity is kept at 621.6mAh/g, and the capacity retention rate reaches 60.2%. Under the current density of 5C, the specific discharge capacity still reaches 437.5mAh/g, and the multiplying power also shows excellent electrochemical performance.

Claims (9)

1. A preparation method of transition metal sulfide/carbon of a lithium ion battery cathode material is characterized by comprising the following steps:
(1) Dispersing metal sulfate, a carbon source and a molten salt medium into certain water, and stirring into a uniform mixed solution;
(2) Transferring the mixed solution into an evaporating dish, and setting freezing temperature and freezing time for freeze drying;
(3) And (3) grinding the sample subjected to freeze drying in the step (2) into powder, performing high-temperature heat treatment in a sintering atmosphere, and desalting and drying to obtain the TMS/C composite material with the laminated structure.
2. The method for preparing transition metal sulfide/carbon as the negative electrode material of the lithium ion battery according to claim 1, wherein in the step (1), the mass ratio of the metal sulfate to the carbon source to the molten salt medium is 1: (0.5-1): (4-6); stirring for 2 hours at normal temperature at the rotating speed of 1000 r/min; the concentration of the metal sulfate in the mixed solution is 0.5mol/L.
3. The method for preparing transition metal sulfide/carbon of negative electrode material of lithium ion battery as claimed in claim 1 or 2, wherein in step (1), the metal sulfate is one of ferrous sulfate, cobalt sulfate, copper sulfate, nickel sulfate, stannous sulfate and vanadyl sulfate.
4. The method for preparing transition metal sulfide/carbon of the lithium ion battery anode material according to claim 1 or 2, wherein in the step (1), the carbon source is one of glucose, citric acid, tartaric acid, phenolic resin and dopamine.
5. The method for preparing the transition metal sulfide/carbon of the lithium ion battery negative electrode material according to claim 1 or 2, wherein in the step (1), the molten salt medium is one or more of sodium chloride, potassium chloride and lithium chloride.
6. The method for preparing the transition metal sulfide/carbon of the lithium ion battery anode material according to claim 1 or 2, wherein in the step (2), the freezing temperature is-50 to-30 ℃, and the freezing time is 12 to 24 hours.
7. The method for preparing transition metal sulfide/carbon of the lithium ion battery anode material according to claim 1 or 2, wherein in the step (3), the sintering temperature is 800-1000 ℃, and the sintering time is 3-5h.
8. The method for preparing transition metal sulfide/carbon of the lithium ion battery anode material according to claim 1 or 2, wherein in the step (3), the sintering atmosphere is one of nitrogen, argon and a mixed atmosphere of argon/hydrogen.
9. The method for preparing transition metal sulfide/carbon of the lithium ion battery negative electrode material according to claim 1 or 2, wherein in the step (3), the desalting and drying process comprises: and putting the sintered sample in an oil bath at the temperature of 60-80 ℃ for desalting for 12-24h, and drying at the temperature of 70-90 ℃ in a vacuum atmosphere for 12-20h.
CN202211025298.2A 2022-08-25 2022-08-25 Preparation method of transition metal sulfide/carbon of lithium ion battery negative electrode material Pending CN115241443A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116212875A (en) * 2023-02-23 2023-06-06 江苏科技大学 FeCo/C catalytic material, feCo/C working electrode and electrochemical sensor

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116212875A (en) * 2023-02-23 2023-06-06 江苏科技大学 FeCo/C catalytic material, feCo/C working electrode and electrochemical sensor

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