CN113620295B - MXene-CoTe composite diaphragm material and preparation method and application thereof - Google Patents
MXene-CoTe composite diaphragm material and preparation method and application thereof Download PDFInfo
- Publication number
- CN113620295B CN113620295B CN202110882940.8A CN202110882940A CN113620295B CN 113620295 B CN113620295 B CN 113620295B CN 202110882940 A CN202110882940 A CN 202110882940A CN 113620295 B CN113620295 B CN 113620295B
- Authority
- CN
- China
- Prior art keywords
- mxene
- layer
- cote
- water
- suspension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/921—Titanium carbide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B19/00—Selenium; Tellurium; Compounds thereof
- C01B19/007—Tellurides or selenides of metals
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/431—Inorganic material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/20—Two-dimensional structures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
- C01P2002/85—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by XPS, EDX or EDAX data
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
- C01P2004/16—Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/20—Particle morphology extending in two dimensions, e.g. plate-like
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
-
- 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
Abstract
The invention discloses an MXene-CoTe composite diaphragm material and a preparation method and application thereof, belonging to the technical field of electrochemical cells. The preparation method of the MXene-CoTe composite material comprises the following steps: (1) With Ti 3 AlC 2 Removing the Al layer part by using a chemical etching-intercalation technology as a raw material, and then dispersing the Al layer part to prepare a few-layer MXene suspension; (2) Adding the small-layer MXene suspension into a mixed solution of water and N, N-dimethylformamide; and then adding cobalt salt, sodium tellurite, alkali, hydrazine hydrate solution and anionic surfactant, reacting, washing and drying to obtain the MXene-CoTe composite material. The composite diaphragm material is applied to the lithium-sulfur battery under high temperature and lean solution, and shows good cycle stability, excellent rate performance and ultrahigh surface capacity.
Description
Technical Field
The invention relates to the technical field of electrochemical cells, in particular to an MXene-CoTe composite diaphragm material and a preparation method and application thereof.
Background
The lithium secondary battery has the advantages of high theoretical specific capacity, high theoretical energy density, low cost, environmental friendliness and the like. However, the Celgard separator commonly used in lithium secondary batteries has poor thermal stability, mechanical strength, and low electrolyte wettability, while it is difficult to suppress the formation of lithium dendrites, resulting in poor thermal stability and safety of the lithium secondary batteries. In addition, as one of representatives of lithium secondary batteries, the lithium sulfur battery has delayed polysulfide conversion kinetics under high temperature and poor liquid conditions, and the accumulation of liquid phase polysulfide is increased, resulting in low sulfur utilization and severe shuttling behavior, thereby facing the lithium sulfur battery with poor cycle stability, poor rate performance, and low energy density.
In order to solve the above problems, a heat-resistant separator material having an electrocatalytic function has been conventionally constructed, which not only accelerates the conversion of polysulfide and alleviates the accumulation and shuttling behavior of polysulfide in an electrolyte, but also improves the heat resistance and wettability of the separator, suppresses the formation of lithium dendrites, and ensures excellent thermal stability and safety of a lithium secondary battery. MXene is a novel two-dimensional material, and high sulfur catalytic activity and strong lithium affinity can be realized by regulating and controlling the functional group of the body. However, due to the effect of van der waals forces, MXene nanoplatelets tend to agglomerate and accumulate, resulting in a large loss of the surface of the functional groups that catalyze the polysulfide conversion. Meanwhile, the transition metal sulfur/selenium compound has low electrical conductivity and poor thermal stability, resulting in low catalytic activity and poor structural stability during electrochemical reaction.
At present, a novel transition metal chalcogenide/MXene composite material needs to be prepared, the problems of structural stability of the transition metal chalcogenide and MXene self-accumulation are solved, the conductivity, the catalytic activity and the specific surface area of the composite material are improved, the conversion reaction of polysulfide is accelerated, and the formation of lithium dendrite is inhibited.
Disclosure of Invention
The composite diaphragm material solves the problems of structural stability of transition metal chalcogenide and self-accumulation of MXene, improves the conductivity and catalytic activity of the composite material, can accelerate the conversion reaction of polysulfide and inhibit the formation of lithium dendrite. In addition, the composite diaphragm material can improve the heat resistance, wettability and mechanical strength of the Celgard diaphragm; the composite diaphragm material is applied to the lithium-sulfur battery under high temperature and lean solution, has good cycle stability, excellent rate capability and ultrahigh surface capacity, and obviously improves the thermal stability and safety of the high specific energy lithium secondary battery.
The invention firstly provides a preparation method of MXene-CoTe composite material, which comprises the following steps:
(1) With Ti 3 AlC 2 Removing the Al layer part by using a chemical etching-intercalation technology as a raw material, and then dispersing the Al layer part to prepare a few-layer MXene suspension;
(2) Adding the small-layer MXene suspension into a mixed solution of water and N, N-Dimethylformamide (DMF); and then adding cobalt salt, sodium tellurite, alkali, hydrazine hydrate solution and anionic surfactant, reacting, washing and drying to obtain the MXene-CoTe composite material.
In the above preparation method, the etchant used in the chemical etching-intercalation technology is at least one of hydrofluoric acid, calcium chloride, sulfuric acid and hydrochloric acid;
the intercalation agent used by the chemical etching-intercalation technology is selected from one of ethanol, tetramethyl ammonium hydroxide and dimethyl sulfoxide.
In the step (1), the dispersing agent for dispersing is water; specifically, deionized water may be used.
In particular, with Ti 3 AlC 2 The specific steps for preparing a few-layer MXene suspension for the starting material are as follows: mixing and stirring lithium fluoride and hydrochloric acid, and then mixing Ti 3 AlC 2 Adding the mixture, and continuously stirring the mixture for 12 to 48 hours at the temperature of between 30 and 60 ℃; centrifuging and pouring out the supernatant; adding water into the precipitate, performing ultrasonic treatment, centrifuging, and pouring out the supernatant; repeating the water adding and ultrasonic centrifuging steps until the pH value of the poured liquid is 6; and then adding ethanol into the precipitate for ultrasonic treatment, centrifuging, collecting the lower-layer precipitate, adding water, shaking uniformly, performing ultrasonic treatment, centrifuging, and collecting the black rice dumpling color upper solution as a few-layer MXene suspension.
The lithium fluoride and Ti 3 AlC 2 The mass ratio of (a) to (b) is 1:1; the concentration of the hydrochloric acid is 9mol/L; the Ti 3 AlC 2 And hydrochloric acid at a mass to volume ratio of 1g to 20mL.
And simultaneously introducing argon inert gas in the ultrasonic process.
The water is deionized water.
In the above preparation method, in the step (2), the volume ratio of the water to the N, N-dimethylformamide is 1; specifically 1.5-2 or 1:1;
the concentration of the small-layer MXene suspension is 3-10 mol/L; specifically, the concentration can be 5-10 mol/L, 5-8 mol/L or 5mol/L;
the few-layer MXene suspension: the volume ratio of the mixed solution of water and N, N-dimethylformamide is 1; specifically, the ratio of 1.
In the preparation method, in the step (2), the cobalt salt is cobalt chloride, cobalt sulfate or cobalt acetate;
the alkali is sodium hydroxide and/or potassium hydroxide;
the anionic surfactant is one of sodium dodecyl sulfate, sodium dodecyl sulfate and sodium alkyl polyoxyethylene ether carboxylate;
the mass percentage concentration of the hydrazine hydrate solution is 40-80%; specifically 80 percent;
the molar ratio of the cobalt salt to the sodium tellurite is 1.5-1.5; specifically 1:1;
less layers of MXene in the less layers of MXene suspension: cobalt salt: alkali: hydrazine hydrate: the molar ratio of the anionic surface activity is 40-100; specifically, the ratio of the compound is 50-100; more specifically, the ratio of 70-100.
In the preparation method, in the step (2), the small-layer MXene suspension is added into a mixed solution of water and N, N-dimethylformamide and then stirred and subjected to ultrasonic treatment;
specifically, the stirring time can be 10-120 min; specifically 10-30 min; the ultrasonic time can be 20-120 min; specifically, the time can be 30-120 min, 20-50 min, 20-40 min or 30mim;
the method also comprises the step of stirring the solution before the reaction, wherein the stirring time is 0.5-3h; specifically, the time can be 0.5-2 h or 1h.
In the preparation method, in the step (2), the reaction is carried out for 6 to 36 hours at the temperature of 140 to 200 ℃ in a sealing way;
specifically, the reaction temperature is 160-200 ℃, 170-190 ℃ or 180 ℃; the reaction time is 10-25 h, 15-25 h or 20h;
the reaction is carried out in a hydrothermal kettle;
the washing sequentially adopts absolute ethyl alcohol and water; the number of washing times can be 3 respectively;
the drying is vacuum drying for 10 to 48 hours at the temperature of between 50 and 80 ℃; specifically, the drying temperature is 60 ℃; the drying time is 12-48 h, 12-24 h, 12-15 h or 12h.
The second purpose of the invention is to provide the MXene-CoTe composite material prepared by the preparation method.
The application of the MXene-CoTe composite material in preparing the battery diaphragm also belongs to the protection scope of the invention.
The invention also provides a battery diaphragm, which comprises the MXene-CoTe composite material and a base film;
specifically, the base membrane is a PE single-layer diaphragm, a PP single-layer diaphragm or a PP/PE/PP three-layer diaphragm.
The base film may specifically be a Clegard film or a Clegard2325 film.
Further, the invention also provides a preparation method of the battery diaphragm, which comprises the following steps: and mixing the MXene-CoTe composite material with an adhesive, and coating the mixture on the base film to obtain the battery diaphragm.
In the preparation method, the mass ratio of the MXene-CoTe composite material to the adhesive is 1:0.1 to 0.4; specifically, 1;
the binder is at least one of polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO).
In the above preparation method, a drying step is further provided after the coating; specifically, the drying is vacuum drying for 12-24 h at 40-80 ℃; in particular to vacuum drying for 12h at 50 ℃.
The coating process is one of scraper coating, spin coating and vacuum filtration.
The thickness of the coating is 10-200 microns; specifically, it may be 10 to 100 micrometers, 10 to 80 micrometers, 10 to 50 micrometers or 10 micrometers.
Mixing the MXene-CoTe composite material with an adhesive in a solvent; specifically, the solvent is N-methylpyrrolidone.
The volume mass ratio of the solvent to the adhesive is 1mL: 0.01-0.05 g; specifically, the concentration can be 1mL.
The application of the battery separator in the preparation of the lithium secondary battery also belongs to the protection scope of the invention.
The invention also provides a lithium secondary battery, and the used diaphragm is the battery diaphragm;
specifically, the lithium secondary battery is a lithium sulfur battery.
The invention has the following advantages:
(1) The MXene-CoTe composite material is a two-dimensional/one-dimensional material, the one-dimensional CoTe nanorod can inhibit the self-agglomeration of MXene, the two-dimensional MXene can provide a large active surface, and the stability of the CoTe catalyst structure is improved, so that the composite material can fully catalyze polysulfide conversion, and Li can fully catalyze polysulfide conversion 2 S deposition/decomposition, reduction of Li 2 The S dissolution potential barrier finally solves the problem of shuttle effect fundamentally and realizes high energy density and cycling stability of the lithium secondary battery;
(2) The MXene-CoTe composite material has high heat resistance, good mechanical strength and electrolyte wettability; meanwhile, the MXene-CoTe composite material provides a large number of lithium-philic functional groups and a high specific surface area, can effectively inhibit the formation of lithium dendrites, and improves the thermal stability and safety of the lithium secondary battery;
(3) The MXene-CoTe composite material prepared by the invention is applied to the lithium-sulfur battery, and the lithium-sulfur battery can still realize 905mAh g at the high temperature of 60 ℃ and under the current density of 3C -1 Specific capacity of (a); the sulfur loading was 8.2mg cm at 60 ℃ high temperature test -2 The electrolyte/sulfur mass ratio was 3. Mu.L.mg -1 Then, the lithium-sulfur battery realizes 9.0mAh cm -2 The face volume of (a); in the electrolyte/sulfur mass ratio of 4. Mu.L. Mg -1 And at a high temperature of 60 DEG CAfter the lithium-sulfur battery is circulated for 30 circles, the surface capacity is still 4.1mAh cm -2 。
Drawings
FIG. 1 is an X-ray diffraction pattern of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1;
FIG. 2 is a scanning electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1;
fig. 3 is a transmission electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1;
FIG. 4 is an X-ray photoelectron spectrum of the MXene nanosheet/cobalt telluride nanorod composite prepared in example 1;
FIG. 5 is a graph of electrocatalytic polysulfide conversion data for MXene nanosheet/cobalt telluride nanorod composites prepared in example 1;
FIG. 6 is a scanning electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite membrane;
FIG. 7 is a thermal stability diagram of an MXene nanosheet/cobalt telluride nanorod composite diaphragm;
FIG. 8 is a contact angle data graph of an MXene nanosheet/cobalt telluride nanorod composite membrane;
FIG. 9 is a diagram of electrochemical performance data of a lithium-sulfur battery assembled by an MXene nanosheet/cobalt telluride nanorod composite membrane under high temperature and lean solution conditions; wherein, a in fig. 9 is a rate performance graph; b in fig. 9 is a charge-discharge curve at a current density of 0.01C; c in fig. 9 is a graph of the cycle performance at a current density of 0.02C.
Detailed Description
The present invention is described in further detail below with reference to specific embodiments, which are given for the purpose of illustration only and are not intended to limit the scope of the invention.
The experimental procedures in the following examples are conventional unless otherwise specified.
Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
Ti in the following examples 3 AlC 2 From Jilin province one-to-one science and technologyA limited company.
Example 1 preparation of MXene nanosheet/cobalt telluride nanorod composite
1) 1g of lithium fluoride and 9M 20mL of hydrochloric acid were stirred in a beaker for 20min, and then 1g of Ti was added 3 AlC 2 Slowly added to the beaker and stirred continuously at 40 ℃ for 36h. Then centrifuging for 15min at 4000rpm, pouring out the supernatant after centrifugation, adding 20mL of deionized water into the precipitate, and carrying out ultrasonic treatment in an ultrasonic machine of 750W for 20min, wherein argon inert gas is introduced during the ultrasonic treatment. The supernatant was decanted by centrifugation and the precipitate was added with deionized water and the ultrasonic centrifugation step was repeated until the pH of the decanted liquid reached 6. Adding 20mL of ethanol, performing ultrasonic treatment for 1h, centrifuging at 10000rpm for 15min, collecting the lower-layer precipitate, adding 10mL of deionized water, shaking up, performing ultrasonic treatment, centrifuging for 5min at 3500 rpm, and collecting the black rice dumpling color upper liquid which is a few-layer MXene suspension with the concentration of 5mol/L.
2) 18mL of the layered MXene suspension at 5mol/L was added to a beaker containing 22mL of deionized water and DMF (at a volume ratio of 1:1), stirred for 20min, and sonicated for 30min. Subsequently, 0.25g (1 mmol) of cobalt sulfate, 0.22g (1 mmol) of sodium tellurite and 0.5g of sodium hydroxide were added to the above solution, respectively. Finally, 4mL of hydrazine hydrate solution (80 wt%) and 1g of sodium dodecylsulfate were added, and stirred for 1h.
3) Adding the solution obtained in the step 2) into a hydrothermal kettle, carrying out sealing reaction for 20h at 180 ℃, sequentially washing with absolute ethyl alcohol and deionized water for three times respectively, and carrying out vacuum drying for 12h at 60 ℃ to obtain the MXene nanosheet/cobalt telluride nanorod composite material.
FIG. 1 is an X-ray diffraction pattern of the MXene nanosheet/cobalt telluride nanorod composite prepared in example 1; by comparison with a standard PDF card, MXene-CoTe composite material can be confirmed.
Fig. 2 is a scanning electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1, and it can be seen that the MXene nanosheet is wrapped by a CoTe nanorod.
Fig. 3 is a transmission electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1, and it can be seen that a few layers of MXene nanosheets and CoTe nanorods with a diameter of 50nm are intermingled.
Fig. 4 is an X-ray photoelectron spectrum of the MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1, and the presence of Ti, C, O, co, and Te elements is confirmed.
Mixing 80wt% of MXene nanosheet/cobalt telluride nanorod composite and 20wt% of PVDF (polyvinylidene fluoride) in NMP (N-methyl pyrrolidone, the volume to mass ratio of NMP to PVDF being 1mL 0.02g) to form a homogeneous slurry. The homogeneous slurry was then coated directly onto carbon paper and dried in an oven at 60 ℃ for 24 hours. The material was used as an electrode to assemble a symmetrical CR2016 coin cell, clegard2325 was a separator, 40. Mu.L Li 2 S 6 Electrolyte (containing 1M LiTFSI, 0.2M LiNO in DOL/DME solvent) 3 And 0.2M Li 2 S 6 DOL and DME in a volume ratio of 1:1) as the battery electrolyte. The electrochemical workstation (CHI 604D) for the symmetrical cell was operated at 0.1mV s under a voltage window of-0.8 to 0.8V -1 The CV curve is measured at the scan rate.
Li 2 Deposition and dissolution testing of S: a CR2025 catalytic cell was assembled by using the above-described electrode as the working electrode and lithium foil as the counter electrode. 25 μ L of Li was used 2 S 8 Electrolyte (containing 0.05M Li in DOL/DME) 2 S 8 And Li of 1M LiTFSI 2 S 8 Solution, DOL and DME in a volume ratio of 1:1) as catholyte, 25. Mu.L Li-free 2 S 8 The above electrolyte is used as an anolyte. For Li 2 Deposition of S was carried out using a catalytic cell at a constant current of 0.112mA to 2.06V and then at a constant potential of 2.05V for 5,000 seconds. For Li 2 And S is dissolved, and the battery is firstly discharged to 1.8V at a constant current of 0.10mA and then discharged to 1.7V at a constant current of 0.01 mA. Finally, the cell was charged potentiostatically at 2.35V until 20000s to dissolve Li sufficiently 2 And S. The test results are shown in FIG. 5.
FIG. 5 is a graph of electrocatalytic polysulfide conversion data for MXene nanoplate/cobalt telluride nanorod composites prepared in example 1; from the cyclic voltammogram of the symmetrical cell in a of fig. 5, three pairs of redox peaks can be seen, representing that the MXene-CoTe composite material can accelerate the conversion reaction between sulfur and lithium sulfide. MXene-CoTe complex can be seen from b in FIG. 5The composite material realizes the lithium sulfide 438.8 mAh.g -1 The deposition capacity of (c). According to c in FIG. 5, MXene-CoTe composite material can be seen to realize 306mAh g of lithium sulfide -1 The dissolution capacity of (a).
Example 2 preparation of MXene nanosheet/cobalt telluride nanorod composite diaphragm
The MXene nanosheet/cobalt telluride nanorod composite material prepared in example 1 and polyvinylidene fluoride are uniformly mixed in N-methyl pyrrolidone (the volume mass ratio of the N-methyl pyrrolidone to the polyvinylidene fluoride is 1mL and 0.02g) according to the mass ratio of 4:1, coated on a Celgard 2325 diaphragm with the diameter of 19mm by a spin coating machine, and dried in vacuum at 50 ℃ for 12 hours, so that the heat-resistant diaphragm for the lithium secondary battery (namely the MXene nanosheet/cobalt telluride nanorod composite diaphragm) is obtained.
Fig. 6 is a scanning electron microscope image of the MXene nanosheet/cobalt telluride nanorod composite membrane, and it can be seen that the MXene nanosheet/cobalt telluride nanorod composite material is uniformly coated on the membrane, and the coating thickness is 10 microns.
Fig. 7 is a thermal stability test of the MXene nanosheet/cobalt telluride nanorod composite membrane, and it can be found that the MXene-CoTe membrane still has no thermal shrinkage at a high temperature of 90 ℃ and has good heat resistance.
The material preparation and testing method in fig. 7 is as follows:
preparation of MXene material: 30mL of the small-layer MXene suspension prepared in the step 1) of the example 1 was taken out, and the suspension was freeze-dried for 48h at-45 ℃ in a freeze dryer.
The preparation method of the CoTe nanorod is consistent with that of the MXene nanosheet/cobalt telluride nanorod composite material in the example 1, except that no small-layer MXene suspension is added.
The preparation method of the diaphragm is consistent with that of the MXene nanosheet/cobalt telluride nanorod composite diaphragm, and only the active material needs to be changed into an MXene material or a CoTe nanorod.
The prepared diaphragm is placed in an oven with different temperature gradients (60-90 ℃) for 1 hour, and then taken out for photographing.
Fig. 8 is a contact angle test of the MXene nanosheet/cobalt telluride nanorod composite membrane, and it can be found that the contact angle of the MXene-CoTe membrane is smaller than that of the MXene and CoTe membranes, and the wettability of the MXene-CoTe membrane to the electrolyte is excellent.
The test method of fig. 8 is as follows:
the materials were prepared as in fig. 7, and the dropping contact angle test was carried out by dropping a certain amount of electrolyte (electrolyte composed of 1mol/L lithium bis (trifluoromethylsulfonyl) imide as lithium salt, solvent 1,3-dioxolane and ethylene glycol dimethyl ether (volume ratio v/v = 1:1), 0.2M lithium nitrate additive) on different separators, and after standing for 2s, measured by a gram Lv Shi DSA100 tester.
Example 3 high temperature-lean solution lithium-sulfur battery electrochemical Performance testing of MXene nanoplate/cobalt telluride nanorod composite membranes
Assembly and testing of lithium sulfur batteries: the heat-resistant diaphragm prepared in example 2 was used as the diaphragm, the negative electrode was a lithium sheet, and the positive electrode was a carbon nanotube/sulfur composite positive electrode material (the carbon nanotube material and elemental sulfur were mixed uniformly in a mass ratio of 2:8, and then added into a sealed can filled with argon, heated at 155 ℃ for 12 hours in a muffle furnace at a rate of 1 ℃ for min -1 To obtain the carbon nano tube/sulfur composite material. ) Electrolyte solution: 1mol/L lithium bis (trifluoromethylsulfonyl) imide is used as lithium salt, the solvent is a mixed solution of 1,3-dioxolane and ethylene glycol dimethyl ether (the volume ratio v/v = 1:1), and 0.2M lithium nitrate additive is used to form electrolyte; assembling the lithium-sulfur battery CR2025 under the conditions of different electrolyte volume to sulfur mass ratios; after standing for 24h, the electrochemical performance of the lithium-sulfur battery was tested in a thermostat at 60 ℃ under a voltage of 1.7-2.8V, and the results are shown in FIG. 9.
FIG. 9 is a diagram of electrochemical performance data of a lithium-sulfur battery assembled by an MXene nanosheet/cobalt telluride nanorod composite membrane under high temperature and lean solution conditions. As can be seen from a in FIG. 9, the lithium-sulfur battery still achieves 1664mAh g at a high temperature of 60 ℃ and at current densities of 0.1C and 3C -1 And 905 mAh. G -1 The specific capacity of (A). From b in FIG. 9, it can be seen that the sulfur loading was 3.7,5.6,8.2mg cm under the high temperature test at 60 deg.C -2 The mass ratio of the electrolytic liquid volume to the sulfur is 7,5,3 muL mg -1 Then, the lithium-sulfur battery realized 4.9,7.2,9.0 mAh.cm -2 The surface area capacity of (a). As can be seen from c in FIG. 9, the volume of electrolyte and the mass of sulfurThe ratio is 4. Mu.L. Mg -1 And under the high temperature condition of 60 ℃, after the lithium-sulfur battery circulates for 30 circles, the surface capacity is still 4.1mAh cm -2 。
Claims (17)
1. The application of the MXene-CoTe composite material in preparing the lithium-sulfur battery diaphragm;
the preparation method of the MXene-CoTe composite material comprises the following steps:
(1) With Ti 3 AlC 2 Removing the Al layer part by using a chemical etching-intercalation technology as a raw material, and then dispersing the Al layer part to prepare a few-layer MXene suspension;
the intercalation agent used by the chemical etching-intercalation technology is selected from one of ethanol, tetramethyl ammonium hydroxide and dimethyl sulfoxide;
(2) Adding the small-layer MXene suspension into a mixed solution of water and N, N-dimethylformamide; then adding cobalt salt, sodium tellurite, alkali, hydrazine hydrate solution and anionic surfactant, reacting, washing and drying to obtain the MXene-CoTe composite material;
in the step (2), the reaction is carried out for 6 to 36 hours at the temperature of 140 to 200 ℃ in a sealing way;
in the step (2), the volume ratio of the water to the N, N-dimethylformamide is 1 to 0.5-4;
the cobalt salt is cobalt chloride, cobalt sulfate or cobalt acetate;
less layers of MXene in the less layers of MXene suspension: cobalt salt: alkali: hydrazine hydrate: the molar ratio of the anionic surfactant is 40 to 100, and the molar ratio is;
the CoTe is a one-dimensional nanorod structure.
2. Use according to claim 1, characterized in that: the etchant used by the chemical etching-intercalation technology is at least one of hydrofluoric acid, calcium chloride, sulfuric acid and hydrochloric acid;
in the step (1), the dispersant for dispersion is water.
3. Use according to claim 1 or 2, characterized in that: in the step (2), the concentration of the small-layer MXene suspension is 3 to 10mol/L;
the few-layer MXene suspension: the volume ratio of the mixed liquid of water and N, N-dimethylformamide is 1.
4. Use according to claim 1 or 2, characterized in that: in the step (2), the alkali is sodium hydroxide and/or potassium hydroxide;
the anionic surfactant is one of sodium dodecyl sulfate, sodium dodecyl sulfate and sodium alkyl polyoxyethylene ether carboxylate;
the mass percentage concentration of the hydrazine hydrate solution is 40-80%;
the molar ratio of the cobalt salt to the sodium tellurite is 1:0.5 to 1.5.
5. Use according to claim 1 or 2, characterized in that: in the step (2), the small-layer MXene suspension is added into a mixed solution of water and N, N-dimethylformamide and then stirred and subjected to ultrasonic treatment;
the method also comprises the step of stirring the solution before the reaction, wherein the stirring time is 0.5-3 h.
6. Use according to claim 5, characterized in that: adding the small-layer MXene suspension into a mixed solution of water and N, N-dimethylformamide, and stirring for 10-120 min; the time of ultrasonic treatment is 20 to 120 min.
7. Use according to claim 1 or 2, characterized in that: in the step (2), absolute ethyl alcohol and water are adopted for washing in sequence;
the drying is carried out for 10 to 48 hours under vacuum at the temperature of 50 to 80 ℃.
8. Use according to claim 7, characterized in that: in the step (2), the reaction is carried out in a hydrothermal kettle.
9. A lithium-sulfur battery diaphragm comprises an MXene-CoTe composite material and a base film;
the preparation method of the MXene-CoTe composite material comprises the following steps:
(1) With Ti 3 AlC 2 Removing the Al layer part by using a chemical etching-intercalation technology as a raw material, and then dispersing the Al layer part to prepare a few-layer MXene suspension;
the intercalation agent used by the chemical etching-intercalation technology is selected from one of ethanol, tetramethyl ammonium hydroxide and dimethyl sulfoxide;
(2) Adding the small-layer MXene suspension into a mixed solution of water and N, N-dimethylformamide; then adding cobalt salt, sodium tellurite, alkali, hydrazine hydrate solution and anionic surfactant, reacting, washing and drying to obtain the MXene-CoTe composite material;
in the step (2), the reaction is carried out for 6 to 36 hours at the temperature of 140 to 200 ℃ in a sealing way;
in the step (2), the volume ratio of the water to the N, N-dimethylformamide is 1 to 0.5-4;
the cobalt salt is cobalt chloride, cobalt sulfate or cobalt acetate;
less layer of MXene in the less layer of MXene suspension: cobalt salt: alkali: hydrazine hydrate: the molar ratio of the anionic surfactant is 40 to 100, and the molar ratio is;
the CoTe is a one-dimensional nanorod structure.
10. The lithium sulfur battery separator according to claim 9, wherein: the base membrane is a PE single-layer diaphragm, a PP single-layer diaphragm or a PP/PE/PP three-layer diaphragm.
11. The lithium sulfur battery separator according to claim 9, wherein: the etchant used by the chemical etching-intercalation technology is at least one of hydrofluoric acid, calcium chloride, sulfuric acid and hydrochloric acid;
in the step (1), the dispersant for dispersion is water.
12. The lithium sulfur battery separator according to claim 9, wherein: in the step (2), the concentration of the small-layer MXene suspension is 3 to 10mol/L;
the few-layer MXene suspension: the volume ratio of the mixed liquid of water and N, N-dimethylformamide is 1.
13. The lithium sulfur battery separator according to claim 9, wherein: in the step (2), the alkali is sodium hydroxide and/or potassium hydroxide;
the anionic surfactant is one of sodium dodecyl sulfate, sodium dodecyl sulfate and sodium alkyl polyoxyethylene ether carboxylate;
the mass percentage concentration of the hydrazine hydrate solution is 40% -80%;
the molar ratio of the cobalt salt to the sodium tellurite is 1:0.5 to 1.5.
14. The lithium sulfur battery separator according to claim 9, wherein: in the step (2), the small-layer MXene suspension is added into a mixed solution of water and N, N-dimethylformamide and then stirred and subjected to ultrasonic treatment;
the method also comprises the step of stirring the solution before the reaction, wherein the stirring time is 0.5-3 h.
15. The lithium sulfur battery separator according to claim 14, wherein: adding the small-layer MXene suspension into a mixed solution of water and N, N-dimethylformamide, and stirring for 10-120 min; the time of ultrasonic treatment is 20 to 120 min.
16. The lithium sulfur battery separator according to claim 9, wherein: in the step (2), absolute ethyl alcohol and water are adopted for washing in sequence;
the drying is carried out for 10 to 48 hours under vacuum at the temperature of 50 to 80 ℃.
17. The lithium sulfur battery separator according to claim 16, wherein: in the step (2), the reaction is carried out in a hydrothermal kettle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110882940.8A CN113620295B (en) | 2021-08-02 | 2021-08-02 | MXene-CoTe composite diaphragm material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110882940.8A CN113620295B (en) | 2021-08-02 | 2021-08-02 | MXene-CoTe composite diaphragm material and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113620295A CN113620295A (en) | 2021-11-09 |
| CN113620295B true CN113620295B (en) | 2022-11-18 |
Family
ID=78382251
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110882940.8A Active CN113620295B (en) | 2021-08-02 | 2021-08-02 | MXene-CoTe composite diaphragm material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113620295B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109742378A (en) * | 2019-01-24 | 2019-05-10 | 安徽师范大学 | A kind of CoTe nano wire-graphene composite material and preparation method thereof |
| CN110729441A (en) * | 2019-10-17 | 2020-01-24 | 广东工业大学 | MXene/polyimide composite battery diaphragm and preparation method and application thereof |
| CN112018349A (en) * | 2020-08-12 | 2020-12-01 | 五邑大学 | CoTe2/MXene composite material and preparation method thereof |
| CN112054199A (en) * | 2020-09-02 | 2020-12-08 | 山东大学 | MoS for high-performance potassium ion battery2/Ti3C2Preparation method of MXene composite material |
-
2021
- 2021-08-02 CN CN202110882940.8A patent/CN113620295B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109742378A (en) * | 2019-01-24 | 2019-05-10 | 安徽师范大学 | A kind of CoTe nano wire-graphene composite material and preparation method thereof |
| CN110729441A (en) * | 2019-10-17 | 2020-01-24 | 广东工业大学 | MXene/polyimide composite battery diaphragm and preparation method and application thereof |
| CN112018349A (en) * | 2020-08-12 | 2020-12-01 | 五邑大学 | CoTe2/MXene composite material and preparation method thereof |
| CN112054199A (en) * | 2020-09-02 | 2020-12-08 | 山东大学 | MoS for high-performance potassium ion battery2/Ti3C2Preparation method of MXene composite material |
Non-Patent Citations (2)
| Title |
|---|
| "Active Site Identification and Evaluation Criteria of In situ Grown CoTe and NiTe Nanoarrays for Hydrogen Evolution and Oxygen Evolution Reactions";Liu Yang等;《Small Methods》;20190510;第3卷(第5期);第1-11页 * |
| 水热模板法合成碲化镍纳米棒;左鹏飞等;《化学研究》;20081215(第04期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113620295A (en) | 2021-11-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111554919B (en) | Positive electrode active material, preparation method thereof and sodium ion battery | |
| CN109755545B (en) | Porous carbon material and preparation method thereof, porous carbon/sulfur composite material, battery positive electrode material, lithium-sulfur battery and application thereof | |
| CN104733708B (en) | A kind of preparation method of the nickle cobalt lithium manganate composite of Surface coating LiFePO4 | |
| CN108199041B (en) | Modified lithium iron phosphate material, preparation method and application | |
| CN103280601B (en) | Method for manufacturing lithium-sulfur battery | |
| CN115101741B (en) | Nitrogen-doped graphene-coated silicon-carbon composite material and preparation method and application thereof | |
| CN114094102A (en) | Secondary battery | |
| CN113823781A (en) | Composite negative electrode material and preparation method thereof | |
| CN107482188B (en) | Hollow core-shell structure composite material and preparation method and application thereof | |
| CN102157727B (en) | Preparation method for nano MnO of negative electrode material of lithium ion battery | |
| CN112751008B (en) | Polyphenol modified zinc-iron based heterojunction oxide carbon nano lithium ion battery cathode composite material and preparation method thereof | |
| CN114447321A (en) | Positive electrode material, positive plate comprising same and battery | |
| Wu et al. | Scalable fabrication of Ni (OH) 2/carbon/polypropylene separators for high-performance Li-S batteries | |
| CN111554905B (en) | Preparation method, product and application of zinc oxide-based carbon composite nano material | |
| CN116230908A (en) | Lithium supplementing agent, positive electrode plate, electrochemical device and preparation method of lithium supplementing agent | |
| CN113620295B (en) | MXene-CoTe composite diaphragm material and preparation method and application thereof | |
| CN114751395A (en) | Nitrogen-doped porous carbon sphere/S composite material, preparation method thereof and application thereof in lithium-sulfur battery | |
| WO2018195837A1 (en) | Metal-sulfur battery and preparation method therefor | |
| CN112374552A (en) | Composite modified graphite negative electrode material and preparation method thereof | |
| US11515516B2 (en) | Method of preparing cathode matertal for a battery | |
| CN117219777B (en) | Lithium supplementing agent, preparation method thereof, positive electrode plate and secondary battery | |
| CN115986087B (en) | Silane coupling agent modified covalent organic framework/graphene composite material, preparation method thereof, electrode and battery | |
| WO2023208007A1 (en) | Composite material, preparation method therefor and application thereof | |
| Huang | Ion-pre intercalation of hydrated vanadium oxide cathode by K+ and its performance in Lithium-ion Battery | |
| CN116470016A (en) | Composite electrode material, electrode plate, preparation method and application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |