Cs + Intercalation high-entropy phosphorus sulfide / MXene composite fiber material, preparation method, application and battery

Abstract

The application belongs to the technical field of battery materials, and specifically discloses a Cs + intercalated high-entropy phosphorus sulfide / MXene composite fiber material, a preparation method, application and battery thereof. + The intercalated high-entropy metal phosphorus sulfide fiber and the MXene nanosheet are self-assembled, the Cs + The mass ratio of the intercalated high-entropy metal phosphorus sulfide fiber to the MXene nanosheet is (4-22):1, wherein the Cs + The intercalated high-entropy metal phosphorus sulfide fiber is Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3. The composite fiber of the application has a diameter of hundreds of nanometers and a length of tens of micrometers, and exhibits excellent rate performance and cycle stability, and can have a specific capacity of 350-450 mAhg ‑1 after 1000 cycles of charge and discharge at a large current density of 10 Ag ‑1 .

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery materials, and particularly relates to a Cs + The application relates to an intercalation high-entropy phosphorus sulfide / MXene composite fiber material, a method for preparing the composite fiber material and application, and application in the field of battery materials. BACKGROUND

[0002] Designing high-capacity and high-rate performance anode materials can further improve the sodium storage performance of sodium ion batteries. Metal phosphorus sulfides (MPS3, M=Mn, Fe, Co, Ni, etc.) are widely studied due to their high theoretical specific capacity, unique two-dimensional structure, large interlayer spacing, excellent ion migration rate, adjustable band gap and rich element combination, and are expected to become the next generation of sodium ion battery anode materials. However, MPS3 still has some limitations, such as low electronic conductivity and serious particle pulverization or agglomeration due to large volume change during charging and discharging, which seriously affects the electrochemical performance of sodium ion batteries.

[0003] Peng et al. combined MnPS3 with graphene by high-energy ball milling and high-temperature argon calcination, successfully prepared a 2D / 2D heterojunction of ultrathin MnPS3 / rGO; compared with the original MnPS3, the obtained MnPS3 / rGO hybrid can enhance the conductivity of the material and improve the volume change during the insertion / extraction process of sodium ion storage, which makes the 2D / 2D heterojunction of the ultrathin MnPS3 / rGO composite material exhibit good cycle performance, and the specific capacity of the material is 290mAh g -1 after 150 cycles at 0.2A g -1, the capacity retention rate reached 92% (Sang Y, Wang L, Cao X, et al. Emerging 2D-Layered MnPS3 / rGO composite as asuperior anode for sodium-ion batteries[J]. Journal of Alloys and Compounds, 2020, 831.). Yan et al. increased the MPS3(M=Fe, Co, Ni) intercalation layer spacing by propylamine at room temperature, improved the ionic conductivity of the material, and thus improved the sodium storage performance of the material (Liang Q, Zheng Y, DuC, et al. General and Scalable Solid-State Synthesis of 2D MPS3(M=Fe, Co, Ni) Nanosheets and Tuning Their Li / Na Storage Properties[J]. Small Methods, 2017, 1(12).). The above-mentioned problems faced by metal phosphosulfides can be significantly improved through intercalation and composite methods. At the same time, the rich element combination of metal phosphosulfides makes it possible to improve the sodium storage properties of materials through high entropy.

[0004] MXene is a type of two-dimensional transition metal carbonitride with excellent electronic conductivity, which is conducive to the transmission of electrons in the material, as well as excellent chemical and volume stability, which helps to improve the cycle life of the battery. However, its capacity is relatively low and it is difficult to apply on a large scale. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a Cs + The intercalated high-entropy phosphosulfide / MXene composite fiber negative electrode material uses MXene as a conductive agent and is compounded with the intercalated high-entropy metal phosphosulfide, so that the material has both excellent electronic conductivity and ionic conductivity. MXene can also accommodate the huge volume changes produced by the metal phosphosulfide during the charging and discharging process, avoiding structural damage.

[0006] The technical solutions of the present invention are as follows:

[0007] The present invention provides a Cs + Intercalated high entropy phosphosulfide / MXene composite fiber materials, including Cs + The intercalated high entropy metal phosphosulfide fibers are self-assembled with MXene nanosheets, and the Cs +The mass ratio of the intercalated high-entropy metal phosphorus sulfide fiber to the MXene nanosheet is (4-22): 1, wherein the Cs + The intercalated high-entropy metal phosphorus sulfide fiber is Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3.

[0008] In an embodiment of the present application, the Cs + The mass ratio of the intercalated high-entropy metal phosphorus sulfide fiber to the MXene nanosheet is more preferably (5-20): 1, for example 5:1, 7:1, 8:1, 10:1, 15:1 or 20:1.

[0009] In an embodiment of the present application, the Cs + The average diameter of the intercalated high-entropy metal phosphorus sulfide fiber is 100-500 nm.

[0010] In an embodiment of the present application, the Cs + The average length of the intercalated high-entropy metal phosphorus sulfide fiber is 50-300 μm.

[0011] In an embodiment of the present application, the MXene nanosheet is a Nb2CSe2 or Ta2CSe2 nanosheet, which has a lateral dimension of 100-2000 nm and a thickness of 3-15 nm.

[0012] The present application also provides the above-mentioned Cs + A preparation method of the intercalated high-entropy phosphorus sulfide / MXene composite fiber material, comprising the following steps: dispersing the Cs + The intercalated high-entropy metal phosphorus sulfide fiber Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The PS3 is dispersed in a solvent, after sufficient dispersion, a dispersion liquid containing the MXene nanosheet is added dropwise while stirring, and after the dropwise addition is completed, the reaction is continued for 0.5-2 h, and the Cs + The intercalated high-entropy phosphorus sulfide and MXene composite fiber material.

[0013] In an embodiment of the present application, the solvent is a conventional solvent in the art, and is preferably deionized water.

[0014] In an embodiment of the present application, the Cs +The intercalated high-entropy metal phosphorus sulfide fiber is added into a solvent, and is ultrasonically treated for 20-40 min to achieve full dispersion.

[0015] In an embodiment of the present application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The preparation method of PS3 comprises the following steps:

[0016] (1) hydrothermal reaction is performed on an aqueous solution containing a manganese salt, a cadmium salt, an iron salt, a nickel salt, a cobalt salt and hexamethylenetetramine to obtain a high-entropy metal hydroxide, wherein the molar ratio of the manganese salt, the cadmium salt, the iron salt, the nickel salt and the cobalt salt is 6:1:1:1:1, the temperature of the hydrothermal reaction is 110-160 ℃, and the hydrothermal reaction time is 4-20 h;

[0017] (2) the high-entropy metal hydroxide, a phosphorus source and a sulfur source are ground and uniformly mixed, and then are moved into a quartz tube, the quartz tube is sealed under vacuum, and a solid-phase reaction is performed at a high temperature of 450-650 ℃ for 8-25 h, and then the high-entropy metal phosphorus sulfide Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 is obtained after washing and drying, wherein the molar ratio of the high-entropy metal hydroxide, the phosphorus source and the sulfur source is 1:1:(3-4);

[0018] (3) the mixture of the high-entropy metal phosphorus sulfide Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 and a CsCl solution is filtered, washed and dried to obtain Cs + The intercalated high-entropy metal phosphorus sulfide fiber Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3.

[0019] In an embodiment of the present application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1In step (1) of the PS3 method, the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt are one or more of nitrate, sulfate and chloride salts of the corresponding metal. For example, the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt are all one of nitrate, sulfate or chloride; or the manganese salt and cadmium salt are nitrate and the iron salt, nickel salt and cobalt salt are sulfate; or the manganese salt is nitrate and the cadmium salt, iron salt, nickel salt and cobalt salt are chloride.

[0020] In one embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (1) of the PS3 method, the ratio of the sum of the molar amounts of the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt to the molar amount of the hexamethylenetetramine is 1:(1.2-4), more preferably 1:(1.5-3), for example 1:2.

[0021] Preferably, the sum of the molar concentrations of the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt in the aqueous solution is (0.02-0.2) mol / L, for example 0.067 mol / L.

[0022] In one embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (1) of the PS3 method, the temperature of the hydrothermal reaction is preferably 115-145°C, for example 120°C, 130°C or 140°C, and the time of the hydrothermal reaction is preferably 5-15 h, for example 6 h, 8 h, 10 h or 12 h.

[0023] The skilled person will routinely dissolve the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt in deionized water before adding the hexamethylenetetramine, and will typically use a polytetrafluoroethylene lined reaction vessel for the hydrothermal reaction. The product will typically be washed and dried after the reaction.

[0024] In one embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (2) of the PS3 method, the phosphorus source is red phosphorus or phosphorus pentasulfide, and the sulfur source is sulfur powder or phosphorus pentasulfide.

[0025] In one embodiment of the application, the Cs0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (2) of the PS3 method, the molar ratio of the high-entropy metal hydroxide, the phosphorus source and the sulfur source is more preferably 1:1:(3.3-4), for example 1:1:3.5.

[0026] In an embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (2) of the PS3 method, the vacuum degree is 10-100 Pa.

[0027] The solid phase reaction is generally carried out in a muffle furnace, and the reaction temperature is preferably 500-600°C, for example 550°C, and the reaction time is preferably 10-24 h, for example 10 h, 15 h or 20 h.

[0028] In an embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (2) of the PS3 method, the solvent for washing is preferably CS2 and ethanol.

[0029] In an embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 In step (3) of the PS3 method, the concentration of the CsCl solution is 0.2-8 mol / L, more preferably 1 mol / L or 5 mol / L, and the Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The ratio of the mass of the PS3 to the volume of the CsCl solution can be (0.5-4) mg / mL, preferably 2 mg / mL.

[0030] In an embodiment of the application, the Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co0.1 In step (3) of the PS3 method, the reaction temperature is preferably 25-85°C, such as 25°C, 50°C or 80°C, and the reaction time is preferably 12-50h, such as 16h, 20h, 24h, 30h or 48h; the reaction is preferably carried out under stirring, more preferably at a rotation speed of 200-800rpm, such as 600rpm.

[0031] In an embodiment of the present application, the method for preparing the dispersion of MXene nanosheets preferably comprises the following steps:

[0032] (1) taking transition metal M, carbon source and selenium powder in a molar ratio of 2:1:2, respectively, adding C6Cl6 for grinding, then moving into a reaction tube, vacuum sealing and calcining to obtain M2CSe2, wherein the transition metal M is niobium powder or tantalum powder, the calcination temperature is 1100-1300°C, and the calcination time is 4-20h;

[0033] (2) adding the M2CSe2 to a n-butyllithium solution under inert gas protection, and reacting at 20-120°C to obtain lithium intercalated M2CSe2 after washing and drying;

[0034] (3) adding the lithium intercalated M2CSe2 to an aqueous sulfuric acid solution, ultrasonicating and centrifuging to obtain the dispersion of M2CSe2 nanosheets from the supernatant.

[0035] In an embodiment of the present application, in step (1) of the method for preparing the dispersion of MXene nanosheets, the carbon source is preferably one or more of graphite, carbon nanotubes, graphene or PVC.

[0036] In an embodiment of the present application, in step (1) of the method for preparing the dispersion of MXene nanosheets, the mass ratio of the transition metal M, the carbon source and the selenium powder to the C6Cl6 is preferably (50-200):1, such as 100:1 or 150:1.

[0037] In an embodiment of the present application, in step (1) of the method for preparing the dispersion of MXene nanosheets, the grinding time can be conventional in the art, and is preferably 2-10min, such as 5min.

[0038] In an embodiment of the present application, in step (1) of the method for preparing the dispersion of MXene nanosheets, the calcination temperature is preferably 1150-1250°C, such as 1200°C, and the rate of temperature rise to the calcination temperature can be 2-10°C / min, such as 5°C / min; the calcination time is preferably 6-10h, such as 8h.

[0039] In an embodiment of the present application, in step (2) of the method for preparing the MXene nanosheet dispersion liquid, the concentration of the n-butyllithium solution can be 1-5 M, preferably 2-3 M, such as 1.5 M, 2 M, 2.5 M, 3 M or 4 M. The solvent in the n-butyllithium solution is a conventional solvent in the art, such as hexane.

[0040] In an embodiment of the present application, in step (2) of the method for preparing the MXene nanosheet dispersion liquid, the mass ratio of the M2CSe2 to the amount of substance of n-butyllithium in the n-butyllithium solution can be conventional in the art, and generally an excess of n-butyllithium is acceptable, preferably 1:(4-12) g / mmol, for example 1:9 g / mmol, 1:9.6 g / mmol or 1:10 g / mmol; the temperature of the reaction is more preferably 25°C, 40°C, 80°C or 120°C; and the time of the reaction is more preferably 1-10 days, for example 2 days, 3 days, 5 days or 8 days.

[0041] In an embodiment of the present application, step (2) of the method for preparing the MXene nanosheet dispersion liquid is preferably that, under the protection of an inert gas, the M2CSe2 is added to the n-butyllithium solution, transferred to a quartz tube, frozen by liquid nitrogen and then vacuum sealed, reacted at 20-120°C for 2-8 days, and then washed and dried by hexane to obtain lithium intercalated M2CSe2.

[0042] Step (2) is more preferably that, under the protection of an inert gas, 1 g of M2CSe2 is added to 5-10 mL of a 1-3 M n-butyllithium solution, transferred to a quartz tube, frozen by liquid nitrogen and then vacuum sealed, reacted at 20-120°C for 2-8 days, and then washed and dried by hexane to obtain lithium intercalated M2CSe2.

[0043] In an embodiment of the present application, in step (3) of the method for preparing the MXene nanosheet dispersion liquid, the concentration of the aqueous sulfuric acid solution is preferably (1x10 -4 -5x10 -3 ) M, for example 2.5x10 -3 M. The mass of the lithium intercalated M2CSe2 to the volume of the aqueous sulfuric acid solution is preferably (0.2-2) mg / mL, for example 0.5 mg / mL; and the ultrasonic time can be 5-20 min, for example 10 min.

[0044] In the process of preparing the MXene nanosheet in the present application, MXene powder is prepared by a high-temperature solid-phase reaction, the MXene powder is then subjected to a lithium intercalation reaction in a n-butyllithium solution, and the lithium intercalated M2CSe2 is then added to an aqueous sulfuric acid solution, so that H2 generated by the reaction between Li and H + in the interlayer overcomes the interlayer van der Waals force, and assists in obtaining M2CSe2 nanosheets by ultrasonic treatment.

[0045] The application also provides the Cs + The application also provides the application of the intercalated high-entropy phosphorus sulfide / MXene composite fiber material in battery materials.

[0046] The application also provides a battery comprising a positive electrode, a negative electrode, an electrolyte and a separator, one or more of the positive electrode, the negative electrode, the electrolyte or the separator comprising the Cs + The application also provides the application of the intercalated high-entropy phosphorus sulfide / MXene composite fiber material in battery materials.

[0047] Compared with the prior art, the application has the following beneficial effects:

[0048] The application also provides a Cs + The intercalated high-entropy phosphorus sulfide / MXene composite fiber material, MXene is used as a conductive agent and is combined with the intercalated high-entropy metal phosphorus sulfide, the high-entropy material is used to improve the sodium storage performance of the metal phosphorus sulfide, the intercalation of cesium ions increases the huge interlayer spacing and the vacancy of metal ions, so that the material exhibits excellent ion conductivity, the surface-wrapped MXene nanosheet improves the electronic conductivity of the material, the diameter of the composite fiber of the negative electrode material is hundreds of nanometers, the length is tens of micrometers, and the composite fiber exhibits excellent rate performance and cycle stability, and can be used as a negative electrode material for 10 Ag -1 The specific capacity is maintained at 350-450 mAhg -1 . BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 (a) is an SEM image of the negative electrode material prepared in Comparative Example 1; Figure 1 (b) is a Cs 0.3 Mn 0.4 5Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 SEM image of PS3 fiber; Figure 1 (c) is a Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 AFM image of PS3 fiber; Figure 1 (d) is a TEM image of Nb2CSe2 nanosheet prepared in Example 1; Figure 1 (e) is an AFM image of Nb2CSe2 nanosheet prepared in Example 1;Figure 1 (f) SEM image of the composite fiber prepared in Example 1;

[0050] Figure 2 XRD pattern of the negative electrode material of Comparative Example 1 and Example 1;

[0051] Figure 3 Rate performance graph of the electrode material prepared in Comparative Example 1 and Example 1;

[0052] Figure 4 Cycle graph of the electrode material prepared in Example 1 at 10Ag -1 Current density. DETAILED DESCRIPTION

[0053] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0054] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description. In other instances, well-known methods have not been described in detail in order to avoid obscuring the present application.

[0055] Example 1

[0056] Cs + Preparation of intercalated high-entropy metal phosphorus sulfide fiber: that is, preparation of Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3:

[0057] (1) 1.2 mmol, 0.2 mmol, 0.2 mmol, 0.2 mmol and 0.2 mmol of manganese nitrate, cadmium nitrate, ferrous nitrate, nickel nitrate and cobalt nitrate, respectively, were weighed, dissolved in 30 ml of deionized water, 4 mmol of hexamethylenetetramine was added, and after dissolution, it was placed in a 50 ml polytetrafluoroethylene lined reaction kettle, and hydrothermally treated at 120°C for 12 hours. After washing with deionized water and ethanol and drying, a high-entropy metal hydroxide was obtained.

[0058] (2) Mn(NO3)2, Cd(NO3)2, Fe(NO3)2, Ni(NO3)2, and Co(NO3)2 were weighed according to the molar ratio of 1:1:3.5, and red phosphorus and sulfur powder were weighed according to the molar ratio of 1:1:3.5. The high-entropy hydroxide, red phosphorus, and sulfur powder were ground and mixed, and then the mixed powder was transferred into a quartz glass tube. The quartz glass tube was sealed after being vacuumized. The sealed quartz tube was placed in a muffle furnace, and the temperature was raised to 550°C at a rate of 5°C / min. After 10 hours of heat preservation, the precursor high-entropy metal phosphorus sulfide MnPS3was obtained by washing with CS2 and ethanol to remove excess sulfur powder. 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3;

[0059] (3) 100 mg of Mn(NO3)2, 50 mg of Cd(NO3)2, 100 mg of Fe(NO3)2, 100 mg of Ni(NO3)2, and 50 mg of Co(NO3)2 were weighed, and 100 mg of red phosphorus and 350 mg of sulfur powder were weighed. The high-entropy hydroxide, red phosphorus, and sulfur powder were ground and mixed, and then the mixed powder was transferred into a quartz glass tube. The quartz glass tube was sealed after being vacuumized. The sealed quartz tube was placed in a muffle furnace, and the temperature was raised to 550°C at a rate of 5°C / min. After 10 hours of heat preservation, the precursor high-entropy metal phosphorus sulfide MnPS3was obtained by washing with CS2 and ethanol to remove excess sulfur powder. 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3was placed in a beaker containing 50 ml of 1M CsCl aqueous solution, and the opening was sealed with a sealing film. The beaker was stirred at 25°C for 48 hours at a stirring speed of 600 revolutions per minute. After stirring, the product was obtained by vacuum filtration, washing, and drying. + The intercalated high-entropy metal phosphorus sulfide fiber is Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3fiber.

[0060] Nb2CSe2nanosheet preparation:

[0061] (1) 1 g of niobium powder, carbon nanotubes (YFT401, Yufen Technology), and selenium powder were weighed in a molar ratio of 2:1:2, and 10 mg of C6Cl6was added. The mixture was ground manually for 5 minutes, and then the mixed powder was transferred into a quartz tube. The quartz tube was sealed after being vacuumized. The sealed quartz tube was placed in a muffle furnace, and the temperature was raised to 1200°C at a rate of 5°C / min. After 8 hours of heat preservation, Nb2CSe2MXene was obtained.

[0062] (2) 1 g of Nb2CSe2was weighed and added to 5 ml of 2M n-butyllithium hexane solution under an Ar atmosphere. The mixture was transferred into a quartz tube and vacuum-sealed after being frozen with liquid nitrogen. After 8 days of reaction at room temperature, the product was washed several times with hexane and dried to obtain lithium-intercalated Nb2CSe2powder.

[0063] (3) to 200 ml of deionized water, 1 ml of 0.5M aqueous sulfuric acid solution was added dropwise, and after stirring uniformly, 50 mg of lithium intercalated Nb2CSe2 was added, and ultrasonic was performed for 10 min. After ultrasonic, 2000 rpm centrifugation was performed per minute, and the supernatant was taken to obtain a Nb2CSe2 nanosheet dispersion liquid. A certain amount of dispersion liquid was dried to determine the concentration of the dispersion liquid;

[0064] Cs of Example 1 of the application + Preparation of intercalated high-entropy phosphorus sulfide / Nb2CSe2 composite fiber material:

[0065] 100 mg of Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The PS3 fiber was added to 100 ml of deionized water and ultrasonically dispersed for 30 minutes. The Nb2CSe2 nanosheet dispersion liquid was added dropwise at a fiber to MXene nanosheet mass ratio of 8:1, and the Nb2CSe2 nanosheet dispersion liquid was added dropwise while stirring vigorously. After the addition was completed, stirring was continued for 1 hour, and the Nb2CSe2 coated Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 composite fiber CMCFNC@N1.

[0066] Example 2

[0067] Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The preparation of the PS3 fiber is the same as in Example 1;

[0068] Preparation of Ta2CSe2 nanosheet:

[0069] (1) 1 g of tantalum powder, graphite powder (Macklin, 99.95%) and selenium powder in a molar ratio of 2:1:2 was weighed, 10 mg of C6Cl6 was added, and manual grinding was performed for 5 minutes. Then the mixed powder was moved into a quartz tube, and the quartz tube was sealed after being vacuumized. The sealed quartz tube was placed in a muffle furnace, and the temperature was raised to 1200℃ at a rate of 5℃ / min, and the temperature was maintained for 10 hours to obtain Ta2CSe2 MXene;

[0070] (2) Weigh 1 g of Ta2CSe2 and add it to 3 ml of a 3 M n-butyllithium hexane solution under an Ar atmosphere. Transfer the mixture to a quartz tube, freeze it with liquid nitrogen, and then vacuum seal it. After reacting at 120°C for 2 days, rinse it several times with hexane and dry it to obtain lithium-intercalated Ta2CSe2 powder.

[0071] (3) Add 400 μl of 0.5 M sulfuric acid solution to 100 ml of deionized water, stir thoroughly, then add 50 mg of lithium-intercalated Nb2CSe2 and sonicate for 10 min. After sonication, centrifuge at 2000 rpm and collect the supernatant to obtain a Ta2CSe2 nanosheet dispersion. Dried a certain amount of the dispersion to determine the concentration of the dispersion.

[0072] Cs in Example 2 of the present invention + Preparation of intercalated high entropy phosphosulfide / Ta2CSe2 composite fiber materials:

[0073] Take 100mg Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 fibers were added to 100 ml of deionized water and ultrasonically dispersed for 30 minutes. The Ta2CSe2 nanosheet dispersion was added dropwise at a fiber to MXene nanosheet mass ratio of 8:1, with vigorous stirring. After the addition was complete, stirring was continued for 1 hour, and the Ta2CSe2-coated CsO2 was obtained by filtration, washing, and drying. 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 composite fiber CMCFNC@T1.

[0074] Example 3

[0075] Compared with Example 1, in the preparation of Cs + In the process of inserting high entropy phosphosulfide / Nb2CSe2 composite fiber materials, in addition to Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 Except that the mass ratio of PS3 fiber to Nb2CSe2 nanosheets was adjusted to 5:1, the other operations and conditions were the same as those in Example 1.

[0076] Example 4

[0077] Compared with Example 1, in the preparation of Cs +In the process of inserting high entropy phosphosulfide / Nb2CSe2 composite fiber materials, in addition to Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 Except that the mass ratio of PS3 fiber to Nb2CSe2 nanosheets was adjusted to 20:1, the other operations and conditions were the same as those in Example 1.

[0078] Comparative Example 1

[0079] (1) Manganese powder, red phosphorus, and sulfur powder were weighed in a molar ratio of 1:1:3, placed in an agate mortar, and manually ground for 5 minutes. The mixed powder was then transferred to a quartz glass tube, which was then sealed after evacuation.

[0080] (2) The sealed quartz tube was placed in a muffle furnace, heated to 650°C at 5°C / min, and kept at this temperature for 5 h to obtain MnPS3.

[0081] Comparative Example 2

[0082] Compared with Example 1, except that the mass ratio of fiber to MXene nanosheets in the preparation process of the high entropy phosphosulfide composite material was adjusted to 30:1, the other operations and conditions were the same as those in Example 1.

[0083] The performance tests of Comparative Examples 1 to 2 and Examples 1 to 4 were performed as follows:

[0084] (1) Morphology characterization and XRD characterization

[0085] Figure 1 (a) SEM image of the negative electrode material prepared in Comparative Example 1; Figure 1 (b) is the Cs prepared in Example 1 0.3 Mn 0.4 5Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 SEM images of PS3 fibers; Figure 1 (c) is the Cs prepared in Example 1 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 AFM images of PS3 fibers; Figure 1 (d) TEM image of Nb2CSe2 nanosheets prepared in Example 1; Figure 1 (e) AFM image of Nb2CSe2 nanosheets prepared in Example 1; Figure 1(f) SEM images of the composite fibers prepared in Example 1. According to the test results, the prepared Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The average diameter of the PS3 fibers is 100-500 nm, and the average length is 50-300 μm; the lateral size of the prepared Nb2CSe2 nanosheets is 100-2000 nm, and the thickness is 3-15 nm.

[0086] Figure 2 The XRD patterns of the composite fiber materials of Comparative Example 1 and Example 1, apparently, with the intercalation of Cs + Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The interlayer distance of PS3 is significantly increased.

[0087] Tables 1-4 are respectively the ICP-OES data of the composite fiber materials prepared in Comparative Example 1, the Cs + intercalated high-entropy metal phosphorus sulfide fibers prepared in Example 1, the Nb2CSe2 nanosheets prepared in Example 1, and the Cs + intercalated high-entropy phosphorus sulfide / MXene composite fiber materials prepared in Example 1. (10 mg of sample was taken, 3 ml of aqua regia and 2 ml of 10% hydrofluoric acid solution were added, microwave digestion was performed, and Agilent 5110 (OES) was used for testing.)

[0088] Table 1

[0089] Element Content % Atomic % P 16.47 19.24 S 54.83 61.86 Mn 28.70 18.90

[0090] Table 2

[0091] Element Content % Atomic % P 13.86 19.19 S 43.96 58.81 Mn 10.72 8.37 Fe 2.63 2.02 Co 2.47 1.80 Ni 2.46 1.80 Cd 4.95 1.89 Cs 18.95 6.12

[0092] Table 3

[0093] Element Content % Atomic % Se 45.78 49.83 Nb 54.22 50.17

[0094] Table 4

[0095] Element Content % Atomic % P 12.79 18.42 S 40.24 56.02 Mn 9.96 8.10 Fe 2.21 1.77 Co 2.26 1.71 Ni 2.28 1.73 Cd 4.55 1.81 Cs 15.85 5.32 Se 4.55 2.57 Nb 5.31 2.55

[0096] (2) Electrochemical performance test

[0097] The final products Cs + intercalated high-entropy phosphorus sulfide / MXene composite fiber materials prepared in Examples 1-4 and the fibers obtained from Comparative Examples 1-2 were respectively prepared into electrodes according to the following method and assembled into batteries:

[0098] The product, Super P and CMC were weighed in a mass ratio of 8:1:1, placed in a agate mortar, and manually ground until uniform. Then, an appropriate amount of deionized water was added, and the grinding was continued for 1-2 hours to prepare a slurry. The slurry was uniformly coated on a copper foil using a 250-micron film applicator, and then placed in a vacuum oven with a temperature setting of 100°C for drying for 8 hours. The battery was assembled in an argon glove box with water content less than 0.5 ppm and oxygen content less than 0.5 ppm, using a piece of metallic sodium as the positive electrode, 1M NaPF6 / diethylene glycol dimethyl ether as the electrolyte, and a glass fiber separator. After the battery was left to stand for 12 hours, electrochemical performance testing was performed on a blue electric test system, with a voltage range of 0.01-3.0V (vs. Na / Na + ).

[0099] 10Ag -1 Specific capacity at a current density of 10Ag

[0100] Table 5

[0101]

[0102] Figure 3 Rate performance graph of the electrode material made from Comparative Example 1 and Example 1, according to Figure 3 and Table 5, the high-entropy of metal phosphorus sulfide, the intercalation of Cs + and the coating of MXene significantly improve the rate performance of the negative electrode material. Figure 4 10Ag -1 Specific capacity at a current density of 10Ag -1 The capacity of the product can still be maintained at about 400 mAhg -1 after 2500 cycles at a current density of 10Ag

[0103] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details, nor limit the application to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A Cs + Intercalated high entropy phosphosulfide / MXene composite fiber material, characterized in that Including Cs + The intercalated high entropy metal phosphosulfide fibers are self-assembled with MXene nanosheets, and the Cs + The mass ratio of the intercalated high entropy metal phosphosulfide fiber to the MXene nanosheet is (4-22):1, wherein the Cs + Intercalated high entropy metal phosphosulfide fibers are Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3.

2. Cs according to claim 1 + Intercalated high entropy phosphosulfide / MXene composite fiber material, characterized in that The MXene nanosheets are Nb2CSe2 or Ta2CSe2 nanosheets.

3. Cs according to claim 1 or 2 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: The following steps are involved: The Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3 is dispersed in a solvent, and a dispersion containing the MXene nanosheets is added dropwise to obtain Cs + Intercalated high entropy phosphosulfide and MXene composite fiber materials.

4. Cs according to claim 3 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: The Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The preparation of PS3 includes the following steps: (1) subjecting an aqueous solution containing a manganese salt, a cadmium salt, an iron salt, a nickel salt, a cobalt salt, and hexamethylenetetramine to a hydrothermal reaction to obtain a high entropy metal hydroxide, wherein the molar ratio of the manganese salt, the cadmium salt, the iron salt, the nickel salt, and the cobalt salt is 6:1:1:1:1, the hydrothermal reaction temperature is 110-160° C., and the hydrothermal reaction time is 4-20 h; (2) Grinding and mixing the high entropy metal hydroxide, phosphorus source and sulfur source, and then transferring them into a quartz tube, sealing the tube under vacuum conditions, and reacting them at a high temperature of 450-650 ° C for 8-25 hours, and then washing and drying to obtain high entropy metal phosphosulfide Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3, wherein the molar ratio of the high entropy metal hydroxide, the phosphorus source and the sulfur source is 1:1:(3-4); (3) Mn 0.6 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 The mixture of PS3 and CsCl solution was reacted at 20-90℃ for 10-60h, and then filtered, washed and dried to obtain Cs + Intercalated high entropy metal phosphosulfide fibers Cs 0.3 Mn 0.45 Cd 0.1 Fe 0.1 Ni 0.1 Co 0.1 PS3.

5. Cs according to claim 4 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: In step (1), the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt are one or more of nitrates, sulfates and hydrochlorides of the corresponding metals.

6. Cs according to claim 4 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: In step (1), the ratio of the sum of the molar amounts of the manganese salt, cadmium salt, iron salt, nickel salt and cobalt salt to the molar amount of the hexamethylenetetramine is 1:(1.2-4).

7. Cs according to claim 4 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: In step (2), the phosphorus source is red phosphorus or phosphorus pentasulfide; And / or, the sulfur source is sulfur powder or phosphorus pentasulfide.

8. Cs according to claim 3 + The preparation method of intercalated high entropy phosphosulfide / MXene composite fiber material is characterized in that: The preparation of the MXene nanosheet dispersion comprises the following steps: (1) Based on molar weight, a transition metal M, a carbon source, and selenium powder are taken in a ratio of 2:1:2, added to C6Cl6, ground, and then transferred into a reaction tube, which is sealed under vacuum and calcined to obtain M2CSe2, wherein: The transition metal M is niobium powder or tantalum powder, the calcination temperature is 1100-1300°C, and the calcination time is 4-20h; (2) Under the protection of inert gas, the M2CSe2 is added to an n-butyl lithium solution, reacted at 20-120°C, and washed and dried to obtain lithium intercalated M2CSe2; (3) Add lithium intercalated M2CSe2 to the sulfuric acid aqueous solution, centrifuge after ultrasonication, and collect the supernatant to obtain the M2CSe2 nanosheet dispersion.

9. A Cs according to claim 1 or 2 + Application of intercalated high entropy phosphosulfide / MXene composite fiber materials in battery materials.

10. A battery comprising a positive electrode, a negative electrode, an electrolyte and a separator, wherein one or more of the positive electrode, the negative electrode, the electrolyte or the separator comprises the Cs as claimed in claim 1 or 2 + Intercalated high entropy phosphosulfide / MXene composite fiber materials.

Images