CN111403731B

CN111403731B - 3d orbital alloy sulfide material and preparation method and application thereof

Info

Publication number: CN111403731B
Application number: CN202010236657.3A
Authority: CN
Inventors: 郭灏; 唐立成; 曹云鹤; 吴宁宁; 郭胜楠; 王畅; 杨程响; 唐康康; 王储; 滕久康; 石斌; 邹睿; 陈铤
Original assignee: Guizhou Meiling Power Supply Co Ltd
Current assignee: Guizhou Meiling Power Supply Co Ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-11-03
Anticipated expiration: 2040-03-30
Also published as: CN111403731A

Abstract

The invention relates to the technical field of battery materials, in particular to a 3d orbital alloy sulfide material and a preparation method and application thereof, wherein the chemical formula of the 3d orbital alloy sulfide material is Fe_0.5Co_xNi_yS₂The preparation method comprises the steps of crushing, melting, hydrothermal reaction and high-temperature purification, and the 3d orbital alloy sulfide material is used for preparing a positive electrode for a thermal battery, a positive electrode for a lithium-sulfur battery and a negative electrode for a sodium-ion battery.

Description

3d orbital alloy sulfide material and preparation method and application thereof

Technical Field

The invention relates to the technical field of battery materials, in particular to a 3d orbital alloy sulfide material and a preparation method and application thereof.

Background

Transition metal sulfide materials, such as iron disulfide, cobalt disulfide, nickel disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide, niobium disulfide, and the like, have semiconductor or superconducting properties, and are widely applied to the fields of light, electricity, and the like.

The thermal battery is a storage type primary battery taking molten salt as electrolyte, the main action objects are missile and nuclear weapons, common anode materials of the thermal battery are transition metal sulfides such as iron disulfide, cobalt disulfide and nickel disulfide, but capacity release bottlenecks caused by slow kinetic reaction limit capacity release of the anode materials and hinder development of the high-specific-energy thermal battery.

The lithium-sulfur battery is a secondary battery using electrolyte, the main action object of the lithium-sulfur battery is an unmanned device, common elemental sulfur of the battery is used as a positive electrode active material, and a carbon-based, oxygen-based and sulfur-based transition metal compound is matched with the positive electrode active material to be used as a sulfur load body, so that excellent high specific capacity is provided, but the development of the lithium-sulfur battery is greatly limited by the shuttle effect of the elemental sulfur.

The sodium ion battery is a secondary battery using electrolyte, the main action object is a power supply of a base station, a metal sodium sheet or transition metal sulfide is commonly used as a negative electrode, and compared with the sodium sheet, the transition metal sulfide has the characteristics of low price, good cyclicity and high safety (without dendrite), but the development of the transition metal sulfide is limited by the poor embedding reaction kinetics of the transition metal sulfide, and the conversion type transition metal sulfide cannot be used.

In order to solve the problems of the prior art, an alloying strategy is usually adopted; the document Angew Chem Int Ed Engl,2016,55(41):12822-12826 reports the single-phase binary alloy sulfide Fe_xCo_1-xS₂In sodium-ion batteriesThe application, but no record of the influence of the third metal element on the crystal structure, the physical property and the electrochemical performance of the third metal element is mentioned; fe was synthesized in JAlloys Compd,2018,762:109-_0.5Co_0.5S₂The single-phase material also discloses the performance characteristics of the single-phase material in a thermal battery, and does not relate to the record of the influence of a third metal element on the crystal structure, the physical characteristics and the electrochemical performance of the single-phase material after being doped; synthesis of Ni from the literature Carbon,2015,90:44-52_xCo_1-xS₂The single-phase material is applied to a super capacitor, and the influence of the doped third metal element on the crystal structure, the physical property and the electrochemical performance is not described.

Patent 201810792243.1 firstly alloys compound Fe_xCo_1-xS₂、Fe_xNi_1-xS₂、Co_xNi_1-xS₂Or Fe_xCo_yNi_1-x-yS₂One of the above, 0 < x < 1, 0 < x + y < 1, has been used in thermal batteries, but there is no report on how to make Fe_xCo_yNi_1-x-yS₂(0 < x < 1, 0 < x + y < 1) high thermal stability and a description of how to change it to release abnormal capacity; patent 201811282657.6 discloses a metal sulfide prepared by using at least one of nickel source, iron source, cobalt source and molybdenum source as metal source and thiourea as sulfur source, and it is used as counter electrode in dye-sensitized solar cell and applied in hydrogen production by electrolyzing water, but its application range in electrode is narrow.

In the prior art, no reports about the embedded single-phase 3d orbital alloy sulfide Fe-Co-Ni-S type material with high thermal stability exist, and the inconsistent cation valence state of the material is not described. Therefore, the sulfide which contains the whole 3d orbital transition metal VIII group element and has different valence states simultaneously is synthesized, and the sulfide has great research value and engineering application prospect.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: directly synthesizes a product which is not stored before without adopting a cladding strategyHigh heat stability embedded single phase material Fe with special valence state_0.5Co_xNi_yS₂(x is more than 0 and less than 0.3, and x + y is 0.5), the material provides unusual high-performance capacity through a unique cation conversion mechanism and self chemical characteristics, and three brand-new electrode material preparation methods are provided based on the characteristics of the material and are applied to a thermal battery, a lithium-sulfur battery and a sodium-ion battery to realize that 3d orbital alloy sulfide Fe in different system batteries_0.5Co_xNi_yS₂Can be used as both anode material and cathode material.

The method is realized by the following technical scheme:

the invention aims to provide a 3d orbital alloy sulfide material, wherein the chemical formula of the 3d orbital alloy sulfide material is Fe_0.5Co_xNi_yS₂Wherein x is more than 0 and less than 0.3, and x + y is 0.5.

Fe in the 3d orbital alloy sulfide material is only +3 valence, and Co and Ni have +2 valence and +3 valence simultaneously.

The 3d orbital alloy sulfide material is Fe³⁺Form Fe_0.5As the insertion type body, Co and Ni ions having both a divalent and a trivalent are doped to form an insertion type compound.

The 3d orbital alloy sulfide material has a hollowed "raspberry" -like microstructure.

The 3d orbital alloy sulfide belongs to an embedded compound and only has a single-phase diffraction peak, wherein the single-phase diffraction peak refers to a pure-phase NiS corresponding to an initial diffraction angle in a main characteristic peak type of material XRD₂The diffraction angle of the XRD characteristic peak point and the stop diffraction angle of the XRD characteristic peak point correspond to pure phase FeS₂The diffraction angle of the XRD characteristic peak point of the compound is in pure phase CoS₂A proximity offset; the 3d orbital alloy sulfide material has high thermal stability, wherein the high thermal stability means that a main heat absorption peak value in a DSC test curve of the material is above 700 ℃; the 3d orbital alloy sulfide material has a special valence state, wherein Fe is only +3 valence, but Co and Ni exist +2 valence and +3 valence at the same time.

One of the purposes of the invention is to provide a preparation method of a 3d orbital alloy sulfide material, which is obtained by crushing ferric salt, adding nickel salt and cobalt salt, crushing, adding sulfur salt, crushing, melting, performing hydrothermal reaction and performing high-temperature purification treatment.

Further, the preparation method of the 3d orbital alloy sulfide material comprises the following steps:

(1) crushing: firstly, putting ferric salt into a crusher to be crushed, simultaneously adding nickel salt and cobalt salt to be crushed, adding sulfur salt to be crushed, and uniformly mixing until a product passes through a 100-mesh sieve to obtain a pink mixture;

(2) melting: treating pink mixed product at 100-120 deg.c to obtain purple black molten liquid;

(3) hydrothermal reaction: adding water into the purple black melt to dilute the purple black melt to prepare a purple black solution, then putting the purple black solution into a hydrothermal reaction kettle, sealing the hydrothermal reaction kettle, and heating the hydrothermal reaction kettle at the temperature of 160-200 ℃ for 2-6 hours;

(4) high-temperature purification: taking out the hydrothermal reaction product, cooling to room temperature, filtering to obtain black precipitate, washing with water, and removing water; heating the mixture to 450-480 ℃ in a tubular furnace under the protection of argon, preserving heat, and cooling to obtain the 3d orbital alloy sulfide material Fe_0.5Co_xNi_yS₂。

The preparation method of the 3d orbital alloy sulfide material specifically comprises the following steps:

(1) crushing: weighing transition metal salt and sulfur salt according to a stoichiometric ratio, wherein the transition metal salt is ferric salt, cobalt salt and nickel salt, and the sulfur salt is controlled to be 2.1-3.2 times of the molar ratio of the transition metal salt; putting an iron salt into a high-energy crusher, crushing for 20-120 s at the rotating speed of 3000r/min, adding a nickel salt and a cobalt salt, crushing for 20-120 s at the rotating speed of 3000r/min, adding a sulfur salt, crushing for 10-60 s at the rotating speed of 3000r/min, and sieving with a 100-mesh sieve, wherein an unscreened product is crushed for several times at the rotating speed of 3000r/min, and the crushing time is 30s each time until all products are sieved with the 100-mesh sieve, so that a pink mixed product is obtained;

(2) melting: putting the pink mixed product into a polytetrafluoroethylene container, putting the polytetrafluoroethylene container into a drying box, and drying the container for more than 20 hours at the temperature of 100-120 ℃ to obtain purple black molten liquid;

(3) hydrothermal reaction: adding water into a polytetrafluoroethylene container containing the purple-black molten liquid to 70-80% of the volume of the container to obtain a purple-black solution; putting the polytetrafluoroethylene container filled with the purple black solution into a hydrothermal reaction kettle, sealing, and heating for 2-6 h at 160-200 ℃;

(4) and (3) drying: taking out the polytetrafluoroethylene container, cooling to room temperature, and filtering to obtain black precipitate; washing the precipitate with water for more than 3 times, and removing water by sublimation in a freeze dryer, or drying at 80 deg.C for 6 hr in a vacuum drying oven with pressure lower than-0.9 Mpa; then heating the steel plate to 450-480 ℃ in a tube furnace under the protection of argon, carrying out heat preservation treatment for 2-4 h, and cooling to obtain a 3d orbital alloy sulfide material Fe_0.5Co_xNi_yS₂。

Preferably, the ferric salt is any one or a mixture of more of ferrous sulfate, ferrous sulfate heptahydrate, ferric nitrate nonahydrate, ferric trichloride and ferric trichloride hexahydrate.

Preferably, the cobalt salt is any one or a mixture of two of cobalt sulfate and cobalt sulfate heptahydrate.

Preferably, the nickel salt is any one or a mixture of nickel sulfate and nickel sulfate hexahydrate.

Preferably, the sulfur salt is any one or a mixture of two of sodium thiosulfate and sodium thiosulfate pentahydrate.

Preferably, the water for washing is any one of deionized water, distilled water and ultrapure water.

The 3d orbital alloy sulfide material is used for preparing a positive electrode for a thermal battery, a positive electrode for a lithium-sulfur battery and a negative electrode for a sodium-ion battery.

One of the purposes of the invention is to provide an application method of the 3d orbital alloy sulfide material, which comprises the following specific steps:

the method for preparing the anode for the thermal battery by using the 3d orbital alloy sulfide material comprises the following steps:

(1) pulping: preparing a 3d orbital alloy sulfide material and acetone into slurry, and then stirring in a closed manner to obtain a 3d orbital alloy sulfide slurry A;

(2) melting: taking foam metal as a carrier, and mixing the following components in percentage by weight: weighing electrolyte salt according to the mass ratio of (2-4) of the electrolyte salt, uniformly spreading the electrolyte salt on a carrier, heating for 2-4 hours in an inert gas environment at 350-550 ℃, and cooling to room temperature to obtain salt-coated foam metal B;

(3) immersing: weighing the 3d track alloy sulfide slurry A and the salt-coated foam metal B according to the mass ratio of (4-10): 1, placing the 3d track alloy sulfide slurry A on the surface of the salt-coated foam metal B one by one, and using a corundum scraper to horizontally scrape and immerse the 3d track alloy sulfide slurry A into the salt-coated foam metal B to obtain a mixed material C;

(4) in-situ synthesis: and drying the mixed material C to remove acetone to obtain a mixed material D, placing the mixed material D in an inert gas environment at 350-550 ℃, heating for 2-4 h, and cooling to room temperature to obtain the anode for the thermal battery.

Preferably, the foam metal in step (2) is nickel foam, iron foam, copper foam or titanium foam.

Preferably, the inert gas in step (2) is argon or nitrogen.

Preferably, the part by part in the step (3) means that the addition amount of the 3d orbital alloy sulfide slurry A per part does not exceed the mass of the salt-coated foamed metal B.

The method for preparing the anode for the lithium-sulfur battery by using the 3d orbital alloy sulfide material comprises the following steps:

(1) sulfur injection: mixing Na₂S₂O₃Mixing with 3d orbit alloy sulfide material, stirring for 30-120 s, melting at 60-100 deg.C, cooling to room temperature, coarse grinding, sieving with 80 mesh sieve, and adding H₂SO₄Stirring the solution at room temperature for 2-4 h, washing with water, and drying in a vacuum drying oven with air pressure lower than-0.9 Mpa to obtain a vulcanized positive electrode A;

(2) purifying: and (2) soaking the vulcanized positive electrode A in the step (1) in a sulfur removal agent for 25-35 min, and washing with absolute ethyl alcohol to obtain the positive electrode for the lithium-sulfur battery.

Preferably, in the step (1), the rotation speed of the mixing and stirring is 400r/min to 1500 r/min.

Preferably, in the step (2), the desulfurizing agent is absolute ethyl alcohol: CS2 is 4:1 by volume.

The method for preparing the cathode for the sodium ion battery by using the 3d orbital alloy sulfide material comprises the following steps:

(1) mixing: mixing the 3d orbital alloy sulfide material and the conductive material according to a mass ratio of 9.9 (0.1-8: 2), and grinding uniformly to form a mixed material A; crushing the metal Sn, sieving the metal Sn by a sieve with the granularity of more than or equal to 60 meshes, and mixing and stirring the mixed material A and the sieved metal Sn for 30-120 s to obtain a mixed material B;

(2) in-situ bonding: and (2) uniformly spreading the mixed material B in the step (1) on a smooth ceramic die, heating to 280-320 ℃, preserving heat for 1-3 h, and cooling to room temperature to obtain the cathode for the sodium-ion battery.

Preferably, in step (2), the ceramic mold is made of boron nitride, silicon nitride, or silicon carbide.

The technical principle of the invention is as follows:

the invention leads the 3d orbit alloy sulfide material Fe to be prepared by a special preparation method_0.5Co_xNi_yS₂The high-temperature-stability and abnormally high specific capacity are achieved; the invention starts from the basic principle, constructs a brand new material frame, and aims at the traditional single-phase anode material FeS in the aspect of capacity design₂、CoS₂、NiS₂In other words, according to the faraday standard charge model equation, the theoretical specific capacities are respectively shown in formulas (1), (2) and (3).

FeS₂：C1＝4×96485As/mol÷120g/mol＝3216As/g (1)

CoS₂：C2＝4×96485As/mol÷123.06g/mol＝3136.19As/g (2)

NiS2：C3＝4×96485As/mol÷122.83g/mol＝3142.06As/g (3)

The 4 electrons are transferred because the Fe, Co and Ni are +2 valence while the S is-1 valence in the above reaction, so that the metal ions become elementary metals of Fe, Co and Ni, and the sulfur is Li₂The S form exists, which is further reduced to-2 valence, so the overall reaction is to transfer 4 valence electrons. However, such a high theoretical specific capacity cannot be completely released, and the release of the capacity is mostly derived from the first reaction equation and the second reaction equation, and the cut-off voltage of the monomer is 1.5V.

For FeS₂For purposes of this specification, the first and second equations are generally recognized as (4) and (5)

FeS₂+1.5Li⁺+1.5e^-→0.5Li₃Fe₂S₄(4)

0.5Li₃Fe₂S₄+0.5Li⁺+0.5e^-→0.5Li₂FeS₂+0.5FeS+0.5Li₂S (5)

It is evident from equation (4) that this is an intercalation reaction, and in step (4), 1.5mol of electrons are completely from S, and FeS is evident₂In (ii) -1 valence S is all changed to Li₃Fe₂S₄In the case of S having a valence of-2, but 0.5mol of electrons are hindered by Fe having a valence of +2, due to Li₃Fe₂S₄Half of the Fe in the alloy is +3, so 2mol of electrons are reduced by self-1 valence sulfur, but because 0.5mol of +2 valence Fe is oxidized, the reaction only provides 1.5mol of electrons; therefore, FeS contributes to capacity₂In fact, it is mainly the anion that provides capacity in redox. In this step, the theoretical specific capacity in formula (6) can be obtained according to the faraday standard charge model equation:

FeS₂：C4＝1.5×96485As/mol÷120g/mol＝1206As/g (6)

whereas for formula (5), 0.5mol of electron transfer is derived from Li₃Fe₂S₄Trivalent Fe in (b) becomes divalent Fe; due to mesophase Li₃Fe₂S₄Derived from FeS₂So according to the Faraday standard charge model equation, canObtaining the theoretical specific capacity in formula (7):

FeS₂：C5＝0.5×96485As/mol÷120g/mol＝402As/g (7)

in this step, however, the capacity is provided by the metal cation, but the second reaction step has a practically very small available capacity, originating from Li₃Fe₂S₄Poor electron conductivity increases ohmic polarization, so for single phase FeS₂Although the theoretical specific capacity can reach 1608As/g when used As a positive electrode active material, the actual specific capacity that can be utilized is often less than 900 As/g.

Interestingly, CoS₂、NiS₂A completely different discharge form is exhibited, and the discharge mechanism of both of them has been significantly changed in recent years, and in the present invention, the result of recent research using neutron diffraction is explained; for CoS₂It adopts reaction equations (8) and (9) obtained by neutron diffraction, and the cut-off voltage of the monomer is 1.4V:

CoS₂+2Li⁺+2e^-→CoS+Li₂S (8)

CoS+2/9Li⁺+2/9e^-→1/9Co₉S₈+1/9Li₂S (9)

in equation (8), it is evident that a shift reaction, 2mol of charge transfer is completely from the anion, redox from S ion of-1 valence to S ion of-2 valence; recent studies have shown that 2mol of electron transfer exceeds the conventionally recognized 1.333mol of electron transfer, so that the theoretical specific capacity in formula (10) can be obtained according to the Faraday standard charge model equation:

CoS₂：C6＝2×96485As/mol÷123.06g/mol＝1568As/g (10)

this is greater than 1045As/g in traditional cognition; in equation (9), 2/9mol of electrons are transferred, and the theoretical specific capacity in equation (11) is obtained according to the Faraday standard charge model equation:

CoS₂：C7＝2/9×96485As/mol÷123.06g/mol＝174As/g (11)

in fact, this part is due to the monomer cut-off voltage being too low (1.4V), and is essentially negligible, even moreWhat is more is the theoretical capacity (monomer cut-off voltage 1.6V) of formula (11); in the same way, NiS₂Is also a conversion reaction, which uses neutron diffraction to obtain the reaction equations (12) and (13):

NiS₂+2Li⁺+2e^-→NiS+Li₂S (12)

NiS+2/3Li⁺+2/3e^-→1/3Ni₃S₂+1/3Li₂S (13)

in equation (12), it is clear that this is also a shift reaction and its theoretical specific capacities are 1571As/g and 523.67As/g, respectively, and the first step reaction equation of the main source of capacity still reveals that the capacity originates from the redox of the anion; and CoS₂The significant difference is that the second reaction almost reaches FeS₂Although the theoretical capacity is As high As 2094.67As/g, the effective release capacity of the second reaction is still not ideal due to the low monomer cut-off (1.4V) and poor conductivity of NiS.

In summary, single-phase FeS₂、CoS₂、NiS₂Has the advantages of inherent high theoretical capacity, but the capacity release seriously restricts the practical use performance of the capacitor due to the limitation of discharge products and self-discharge effect, and more importantly, the NiS₂And CoS₂All are conversion reactions, which further restricts the development of the ion-embedded material; therefore, in the invention, the material is designed and prepared by adopting a technical scheme completely different from the background technology, and the material design method of the invention comprises the following steps:

firstly, using reaction equation (4) as the basis of the new material of the invention, and adding CoS₂And NiS₂The two materials are respectively extracted from reaction equations (8) and (12), and Co and Ni are respectively introduced into FeS₂In the lattice site of (2), a completely new Fe is formed_0.5Co_xNi_yS₂Unit cell, where 0 < x < 0.3, x + y ═ 0.5, and Fe must be based on 0.5, less than this value will not form an ion-embedded structure, but a single phase FeS₂With binary alloy compounds Ni_xCo_1-xS₂Or binary alloy compound Ni_xCo_1-xS and NiCo₂S₄More than this value will reduce the capacity supply and reaction kinetics from Co and Ni, as shown in fig. 8. Furthermore, the present invention strictly limits the molar ratio of Co, and it is desirable to reduce the content of rare metal Co as much as possible to maximize the performance of 3d orbital alloy sulfides at low cost. Based on the reaction equations of (4), (5), (8) and (12) in combination with the discharge data of application example one of the present invention, the present invention proposes new reaction mechanism equations of (14) and (15)

Fe_0.5Co_xNi_yS₂+Li⁺+e^-→LiFe_0.5Co_xNi_yS₂(14)

LiFe_0.5Co_xNi_yS₂+3Li⁺+3e^-→2Li₂S+xCo+yNi+0.5Fe (15)

From the reaction equation, it can be seen that in the first step, the theoretical capacity of the present invention is reduced, and according to the faraday standard charge model equation, the theoretical specific capacity in formula (16) can be obtained:

Fe_0.5Co_xNi_yS₂: c8 ═ 96485As/mol ÷ 121g/mol (ca.) -797.39 As/g (16)

Co/Ni +2/+3 mixed valence state substituted Fe³⁺Production of Fe_0.5Co_xNi_yS₂The phases exhibit electrochemical activity due to the cation Fe²⁺Change to Fe²⁺/Fe³⁺(Charge) and anion S^2-/S^n-Redox (discharge) of (ii); however, the present invention makes creative use of most of the capacity of the subsequent reaction process, since the two reactions share almost the same voltage platform, so it will start to transfer 3mol of electrons at the higher platform, and according to the faraday standard charge model equation, the theoretical specific capacity in formula (17) can be obtained:

Fe_0.5Co_xNi_yS₂: c9 ═ 3 × 96485As/mol ÷ 121g/mol (ca.) -2382 As/g (17)

From the aspect of improving thermal stability, the invention creates a fused salt-hydrothermal synthesis method, so that iron salt, cobalt salt, nickel salt and sulfur salt form homogeneous mixing in a molten stateAnd synthesizing the precursor, and eliminating the solid-solid crystal boundary influence in a molten liquid state, thereby reducing the surface free energy and improving the thermodynamic stability. Thereby only FeS is formed from the original in the four materials in the hydrothermal process₂，CoS₂，NiS₂The three single-phase materials are changed into 3d orbital alloy sulfide Fe_0.5Co_xNi_yS₂。

Has the advantages that:

the 3d orbital alloy sulfide material is an embedded alloy sulfide Fe with high thermal stability_0.5Co_xNi_yS₂Wherein x is more than 0 and less than 0.3, and x + y is 0.5, and the preparation method is respectively applied to the preparation of a thermal battery anode active material, a lithium-sulfur battery anode active material and a sodium ion battery cathode active material, thereby realizing the practical application of the materials under various systems;

(1) in principle, the invention provides a specific chemical formula and a reaction mechanism of 3d orbital alloy sulfide; the invention uses 3-valence Fe element to form an embedded body, and doping trivalent and divalent mixed Co and Ni ions to form an embedded compound; the material designed and synthesized by the invention is completely different from the traditional single-phase material, the capacity far exceeding that of the first step is released by the second step, and most of the capacity can be utilized under a higher voltage platform; in addition, the mixed-valence metal ions are adopted, so that the embedding reaction capacity of the first step is reduced, the reaction conversion of the intermediate phase is accelerated, and the ultrahigh specific capacity reaction process of the second step is performed as soon as possible, so that the larger specific capacity supply in the primary battery is provided; for the secondary battery, the mixed valence metal is beneficial to introducing vacancies to reduce the embedding energy barrier and provide faster ion de-embedding power, thereby fully utilizing the embedding theoretical capacity of the first reaction plateau.

(2) For a thermal battery, the calculated voltage of the cut-off voltage of a monomer reaches 1.5V, and the 3d orbit alloy sulfide material created by the invention brings the actual specific capacity which is up to over 1600 As/g; for lithium-sulfur batteries, the 3d orbital alloy sulfide provided by the invention belongs to a polar material, has excellent chemical adsorption and catalysis effects on polysulfide, and greatly reduces shuttle effect3d rail alloy sulfide is used as a sulfur load, and the formed composite anode material can provide specific capacity of more than 1300 mAh/g; for a sodium ion battery, Co and Ni are creatively replaced by the crystal lattice sites of Fe, so that the energy band width is reduced, the electronic conductivity is enhanced, and CoS which can not be embedded is added₂And NiS₂Introduction of advantages of (1) and synthesis of Fe_0.5Co_xNi_yS₂When the intercalation reaction is performed to form a negative electrode, a discharge capacity of 200mAh/g or more is provided at a high discharge density.

(3) The invention adopts mixed valence metal, firstly FeS is mixed with mixed valence metal₂The Fe in the intermediate phase is increased from +2 valence to +3 valence, then half of trivalent iron is replaced by Co and Ni which have divalent and trivalent functions, the embedding energy barrier is reduced, the embedding reaction power is improved, and the intermediate phase Fe is rapidly completed_0.5Co_xNi_yS₂So that the high-discharge plateau enters a second-step reaction stage with 2382As/g high specific capacity; the valence states of Fe, Co and Ni ions in the alloy sulfide are related to the synthesis method of the invention.

(4) The invention provides a method for preparing an alloy sulfide single-phase material containing the whole 3d orbital transition metal VIII group element by adopting a melting-hydrothermal synthesis method, and precursors of the alloy sulfide single-phase material are uniformly mixed under the condition of eliminating a grain boundary, so that the surface free energy is reduced, and the thermodynamic stability is improved. After hydrothermal synthesis, the DSC main absorption peak can reach more than 700 ℃, and the excellent thermal stability can make the material more stable and provide strong performance.

(5) The method for using the 3d orbital alloy sulfide as the anode material of the thermal battery adopts an in-situ preparation mode, and is completely different from the existing powder pressing process and spraying process. The method adopts the method of integrally molding raw materials and a carrier, so that the finally molded positive electrode has high strength characteristic and is convenient for lamination operation, and simultaneously, the carrier is metal rather than an insulator, such as MgO and Al₂O₃The fiber also greatly enhances the conductivity of the anode, thereby effectively reducing the integral polarization and enabling the active material to output higher capacity.

(6) The method for using the 3d orbital alloy sulfide as the anode material of the lithium-sulfur battery provided by the invention utilizes a hollow raspberry-shaped microstructure of the alloy sulfide, as shown in figure 4, and adopts a mode of melting, mixing and liquid-phase sulfur injection to uniformly load elemental sulfur on the alloy sulfide; and then, the surface sulfur floating of the alloy sulfide is washed away by the sulfur remover, the service time of the sulfur remover is strictly limited, the sulfur remover can not be completely removed when the service time is lower than the limit value, elemental sulfur in the 3d orbit alloy sulfide is washed away when the service time is higher than the limit value, and finally the alloy sulfide with high sulfur loading elemental sulfur is obtained. And due to Fe_0.5Co_xNi_yS₂The polar thiophilic nature of (a) converts the catalytic lithium polysulfide to lithium sulfide, thereby reducing the loss of capacity by the shuttle effect.

(7) The invention provides a method for using 3d orbital alloy sulfide as a negative electrode material of a sodium-ion battery, and provides a preparation method for changing alloy sulfide powder into a flexible pole piece by using an in-situ sheet making method for the first time, wherein the preparation method has the characteristic of thinning; the using amount and the particle size of the metal tin are strictly limited, so that the metal tin can be uniformly mixed, the content of active substances is improved, and meanwhile, better toughness is provided for the cathode.

(8) The invention provides Fe for the first time_0.5Co_xNi_yS₂The molecular structure design and the electrochemical reaction mechanism of the material, and provides a preparation method combining low-temperature melting and hydrothermal reaction, so that the 3d orbital alloy sulfide with high thermal stability is synthesized, and meanwhile, the sulfide plays an excellent role in thermal batteries, lithium-sulfur batteries and sodium-ion batteries, thereby having extremely high research value and engineering application value.

Drawings

FIG. 1 is an XRD test chart of sulfide of 3d orbital alloy in example 1 of the present invention;

FIG. 2 is a representation of Fe in XPS elemental valence analysis of 3d orbital alloy sulfide in example 1 of the present invention;

FIG. 3 is a diagram showing the representation of Co in XPS elemental valence analysis of 3d orbital alloy sulfide in example 1 of the present invention;

FIG. 4 is a representation of Ni in XPS elemental valence analysis of 3d orbital alloy sulfide in example 1 of the present invention;

FIG. 5 is a DSC of sulfide of 3d orbital alloy in example 2 of the present invention;

FIG. 6 is an SEM test chart of sulfides in the 3d orbital alloy in example 3 of the present invention;

fig. 7 is a discharge curve in application example 1 of the present invention;

fig. 8 is a discharge curve in application example 2 of the present invention;

fig. 9 is a discharge curve in application example 3 of the present invention;

figure 10 is an XRD test curve for a chalcogenide material in excess of the proportion of the present invention.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.

Example 1

3d orbital alloy sulfide material Fe_0.5Co_0.2Ni_0.3S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.5Co_0.2Ni_0.3S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, and the molar ratio of the sodium thiosulfate pentahydrate is 2.6 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy pulverizer, crushing for 1min at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 1min at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 30s at a rotating speed of 3000r/min, and sieving by a 100-mesh sieve to obtain a pink mixed product;

(2) melting: putting the pink mixed product prepared in the step (1) into a polytetrafluoroethylene container, and then putting the polytetrafluoroethylene container into a drying oven to dry for 20 hours at the temperature of 110 ℃ to obtain purple black molten liquid;

(3) hydrothermal reaction: adding ultrapure water into the polytetrafluoroethylene container containing the purple-black melt liquid in the step (2) to 70% of the volume of the container to obtain a purple-black solution, then placing the polytetrafluoroethylene container containing the purple-black solution into a hydrothermal reaction kettle, sealing, and heating for 4 hours at 180 ℃;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and placing the precipitate into a freeze dryer for sublimation and water removal; then placing the mixture in a tube furnace under the protection of argon gas, heating the mixture to 480 ℃, preserving heat for 2 hours, and cooling the mixture to obtain a 3d orbital alloy sulfide material Fe_0.5Co_0.2Ni_0.3S₂；

The XRD test result of the 3d orbital alloy sulfide of the embodiment is shown in figure 1, and the XRD characteristic peak range of the material of the invention comprises FeS from the XRD structure₂、CoS₂、NiS₂The characteristic peak values of the three single-phase materials are obtained, so that the embeddability of the structure, the high thermal stability of the performance and the high specific capacity characteristic are realized; the XPS test results are shown in FIGS. 2-4, and as can be seen from FIGS. 2-4, the spectrum of Fe shows that it is close to Fe₂O₃Fe in (2)³⁺Is completely different from FeS₂Fe in (1)²⁺Therefore, the alloy has high binding energy characteristic, and Co and Ni both show the mixed coexistence characteristic of +2 valence and +3 valence, wherein Co²⁺More than Co³ ⁺And Ni³⁺More than Ni²⁺Satellite peaks appear in the high binding energy directions of Fe, Co and Ni, which are caused by strong covalency, and the improvement of the covalency provides stronger reaction power for the material.

The 3d orbital alloy sulfide material Fe_0.5Co_0.2Ni_0.3S₂A method for preparing a positive electrode for a thermal battery, comprising the steps of:

(1) pulping: preparing a 3d orbital alloy sulfide material and acetone into slurry according to a mass ratio of 2:1, and then stirring for 24 hours in a closed container to obtain a 3d orbital alloy sulfide slurry A;

(2) melting: weighing thermal battery electrolyte salt according to the mass ratio of 1:2.9 by taking foamed nickel as a carrier, uniformly and flatly paving LiF-LiCl-LiBr ternary eutectic molten salt on the foamed nickel, heating for 4 hours in an argon environment at 550 ℃, and cooling to room temperature to obtain salt-coated foamed metal B;

(3) immersing: according to the proportion of 3d orbital alloy sulfide slurry A: weighing the salt-coated foam metal B in a mass ratio of 6:1, then placing the 3d track alloy sulfide slurry A on the surface of the salt-coated foam metal B one by one, wherein the addition amount of each 3d track alloy sulfide slurry A is equal to the mass ratio of the salt-coated foam metal B, and then using a corundum scraper to horizontally scrape and immerse the 3d track alloy sulfide slurry A into the salt-coated foam metal B to obtain a mixed material C;

(4) in-situ synthesis: placing the mixed material C in an oven at 70 ℃ for more than 6h, and completely removing acetone to obtain a mixed material D; and then placing the mixed material D in an inert gas environment at 550 ℃ for heating for 2h, and cooling to room temperature to obtain the 3D orbital alloy sulfide anode for the thermal battery.

Example 2

3d orbital alloy sulfide material Fe_0.5Co_0.1Ni_0.4S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.5Co_0.1Ni_0.4S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferric trichloride hexahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, so that the molar ratio of the sodium thiosulfate pentahydrate is 2.7 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy crusher, crushing for 40s at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 40s at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 40s at a rotating speed of 3000r/min, sieving with a 100-mesh sieve, and crushing for several times at a rotating speed of 3000r/min for 30s each time if an object which is not sieved exists, until all products are sieved with the 100-mesh sieve, so as to obtain a pink mixed product;

(2) melting: putting the pink mixed product obtained in the step (1) into a polytetrafluoroethylene container, and then putting the polytetrafluoroethylene container into a drying oven to dry for 22 hours at the temperature of 110 ℃ to obtain purple black molten liquid;

(3) hydrothermal reaction: adding ultrapure water into the polytetrafluoroethylene container containing the purple-black melt liquid in the step (2) to 80% of the volume of the container to obtain a purple-black solution; putting the polytetrafluoroethylene container filled with the purple black solution into a hydrothermal reaction kettle, sealing, and heating at 160 ℃ for 6 hours;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature, filtering to obtain black precipitate, washing with ultrapure water for more than 3 times, and drying the precipitate in a vacuum drying oven with the air pressure of lower than-0.9 Mpa at 80 ℃ for 6 h; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and carrying out heat preservation treatment for 2 hours to obtain the 3d orbital alloy sulfide material Fe_0.5Co_0.1Ni_0.4S₂；

The DSC test result of the 3d orbital alloy sulfide obtained in this example is shown in fig. 5, and it can be seen from the DSC result that the material of this example has only one characteristic peak, so that the material has only one phase transition, so that the 3d orbital alloy sulfide synthesized in this example is a single-phase material, and the main absorption peak reaches 712.5 ℃, which is far superior to that of ordinary FeS₂The thermal decomposition temperature (550 ℃) of (a), indicating that it has good thermal stability;

the 3d orbital alloy sulfide material Fe_0.5Co_0.1Ni_0.4S₂A method for preparing a positive electrode of a lithium-sulfur battery, comprising the steps of:

(1) sulfur injection: mixing Na₂S₂O₃And 3d orbital alloy sulfide material in a mass ratio of 19.8:1 in a planetary mixer, mechanically stirring at a speed of 600r/min for 1min, then melt-mixing at 60 ℃, cooling to room temperature, coarse-grinding to 80 mesh, and adding 0.5M H₂SO₄Stirring the solution at room temperature for 3 hours; then centrifugally washing with deionized water, and then putting the washed solution into a vacuum drying oven with the air pressure lower than-0.9 Mpa to heat and dry at 60 ℃ to obtain a vulcanized positive electrode A;

(2) purifying: and (2) soaking the vulcanized positive electrode A in the step (1) in a sulfur removal agent for 30min, wherein the sulfur removal agent is composed of absolute ethyl alcohol and CS2 according to a volume ratio of 4:1, and then washing with the absolute ethyl alcohol to obtain the 3d rail alloy sulfide positive electrode for the lithium-sulfur battery.

Example 3

3d orbital alloy sulfide material Fe_0.5Co_0.15Ni_0.35S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.5Co_0.15Ni_0.35S₂Weighing transition metal salt and sodium thiosulfate according to a stoichiometric ratio, wherein the transition metal salt is ferric nitrate nonahydrate, cobalt sulfate and nickel sulfate, and the molar ratio of the sodium thiosulfate is controlled to be 3 times that of the transition metal salt; putting ferrous sulfate into a high-energy crusher, crushing for 30s at a rotating speed of 3000r/min, simultaneously adding nickel sulfate and cobalt sulfate, crushing for 30s at a rotating speed of 3000r/min, adding sodium thiosulfate, crushing for 1min at a rotating speed of 3000r/min, sieving with a 100-mesh sieve, continuously crushing substances which cannot be sieved for several times at a rotating speed of 3000r/min until the substances pass through the 100-mesh sieve, wherein the crushing time is 30s each time, and obtaining a pink mixed product;

(2) melting: putting the pink mixed product obtained in the step (1) into a polytetrafluoroethylene container, and then putting the polytetrafluoroethylene container into a drying oven to dry for 24 hours at the temperature of 110 ℃ to obtain purple black molten liquid;

(3) hydrothermal reaction: adding ultrapure water into the polytetrafluoroethylene container containing the purple-black melt liquid in the step (2) to 80% of the volume of the container to obtain a purple-black solution; putting the polytetrafluoroethylene container filled with the purple black solution into a hydrothermal reaction kettle, sealing, and heating at 200 ℃ for 2 hours;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and drying the precipitate in a vacuum drying oven with pressure lower than-0.9 Mpa at 80 deg.C for 6 hr; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and carrying out heat preservation treatment for 2 hours to obtain the 3d orbital alloy sulfide material Fe_0.5Co_0.15Ni_0.35S₂(ii) a The SEM test result of the 3d orbital alloy sulfide obtained in the embodiment is shown in FIG. 6, and it can be seen from the SEM test result that the 3d orbital alloy sulfide prepared by the method orderly forms a larger hollow raspberry-shaped material by small particles of about 100nm, and the raspberry structures are connected in series to form a hierarchical structure, so that the hierarchical structure is reducedThe defect effect of nanocrystallization is reduced, the thermal stability is enhanced by reducing the specific surface energy, and a larger specific surface area is kept, so that the material has more reactive sites; the structure can lead the electrolyte or elemental sulfur or sodium ions to form regular and uniform complete filling, thereby realizing that the electrolyte can meet the application performance requirements of anode materials and cathode active materials.

The 3d orbital alloy sulfide material Fe_0.5Co_0.15Ni_0.35S₂The method for preparing the negative electrode of the sodium-ion battery comprises the following steps:

(1) mixing: mixing the 3d orbital alloy sulfide material and the conductive material according to the mass ratio of 9:1, and grinding uniformly to form a mixed material A; crushing the metal Sn until the metal Sn passes through a 60-mesh sieve, and then placing the mixed material A and the sieved metal Sn in a planetary stirrer according to the mass ratio of 9:1 and mixing and stirring the mixed material A and the sieved metal Sn at a speed of 600r/min for 1min to obtain a mixed material B;

(2) in-situ bonding: and (2) uniformly spreading the mixed material B in the step (1) on a smooth boron nitride mold, heating to 300 ℃, carrying out heat preservation treatment for 2 hours, and cooling to room temperature to obtain the 3d rail alloy sulfide cathode for the sodium-ion battery.

The ICP element weight percentage test analysis of the 3d orbital alloy sulfide material prepared by the methods of the embodiments 1-3 of the invention is shown in the following table 1.

TABLE 1

Group of	Ratio of Fe	Ratio of Co	Ratio of Ni	Ratio of S
					Example 1	22.61	9.52	14.18	53.69
Example 2	22.56	4.76	18.86	53.82
					Example 3	22.65	6.77	16.57	54.01

Comparative example 1

3d orbital alloy sulfide material Fe_0.4Co_0.3Ni_0.3S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.4Co_0.3Ni_0.3S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, and the molar ratio of the sodium thiosulfate pentahydrate is 2.6 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy pulverizer, crushing for 1min at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 1min at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 30s at a rotating speed of 3000r/min, and sieving by a 100-mesh sieve to obtain a pink mixed product;

(4) and (3) drying: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and placing the precipitate into a freeze dryer for sublimation and water removal; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and preserving heat for 2 hours, and cooling to obtain FeS₂And Ni_0.5Co_0.5S₂Mixed phases of (1).

Comparative example 2

3d orbital alloy sulfide material Fe_0.3Co_0.35Ni_0.35S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.3Co_0.35Ni_0.35S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, and the molar ratio of the sodium thiosulfate pentahydrate is 2.6 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy pulverizer, crushing for 1min at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 1min at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 30s at a rotating speed of 3000r/min, and sieving by a 100-mesh sieve to obtain a pink mixed product;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and placing the precipitate into a freeze dryer for sublimation and water removal; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and preserving heat for 2 hours, and cooling to obtain FeS₂And Ni_0.5Co_0.5S₂Mixed phases of (1).

Comparative example 3

3d orbital alloy sulfide material Fe_0.2Co_0.6Ni_0.2S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.2Co_0.6Ni_0.2S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, and the molar ratio of the sodium thiosulfate pentahydrate is 2.6 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy pulverizer, crushing for 1min at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 1min at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 30s at a rotating speed of 3000r/min, and sieving by a 100-mesh sieve to obtain a pink mixed product;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and placing the precipitate into a freeze dryer for sublimation and water removal; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and preserving heat for 2 hours, and cooling to obtain FeS₂And Ni_xCo_1-xS₂、NiCo₂S₄Mixed phases of (1).

Comparative example 4

3d orbital alloy sulfide material Fe_0.1Co_0.5Ni_0.4S₂The preparation method comprises the following steps:

(1) crushing: according to Fe_0.1Co_0.5Ni_0.4S₂Weighing transition metal salt and sodium thiosulfate pentahydrate according to a stoichiometric ratio, wherein the transition metal salt is ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate hexahydrate, and the molar ratio of the sodium thiosulfate pentahydrate is 2.6 times that of the transition metal salt; putting ferrous sulfate heptahydrate into a high-energy pulverizer, crushing for 1min at a rotating speed of 3000r/min, simultaneously adding nickel sulfate hexahydrate and cobalt sulfate heptahydrate, crushing for 1min at a rotating speed of 3000r/min, adding sodium thiosulfate pentahydrate, crushing for 30s at a rotating speed of 3000r/min, and sieving by a 100-mesh sieve to obtain a pink mixed product;

(4) high-temperature purification: cooling the polytetrafluoroethylene container in the step (3) to room temperature and filtering to obtain black precipitate; washing the precipitate with ultrapure water for more than 3 times, and placing the precipitate into a freeze dryer for sublimation and water removal; then placing the mixture in a tube furnace protected by argon gas to heat to 480 ℃ and preserving heat for 2 hours, and cooling to obtain FeS₂And Ni_xCo_1-xS₂、NiCo₂S₄Mixed phases of (a);

the results of the XRD tests of comparative examples 1-4 are shown in FIG. 10, from which it can be seen that: the materials synthesized in the comparison documents 1 to 4 belong to the mixed product, not the single-phase material.

Application example one

Taking the drops obtained by the method of example 130.0g of composite cathode material with low self-discharge degree is taken as cathode material; the diaphragm consists of LiF-LiCl-LiBr and MgO according to the mass ratio of 50:50, and the mass is 8.6 g; the anode material is a LiB alloy sheet with the thickness of 1.1mm and the Li content of 64 percent; placing the anode material, the diaphragm and the cathode material in a 96 mm-diameter die to be punched into sheet-shaped monomers, wherein the total mass is 45.9 g; the heating material is prepared by adopting a patent 201811293098.9 mode; forming a cell stack by 16 single cells of the sheet type, and placing the two cell stacks in a titanium alloy cylinder in a parallel connection mode to form a unit cell; activating the unit cell at 20 deg.C, operating at 43.4A constant current with current density of 300mA/cm²The effective working time (calculated by the cut-off voltage of 25V) of the battery is 1788s, and the actual output specific capacity Fe of the 3d orbital alloy sulfide_0.5Co_0.2Ni_0.3S₂At 1616.6As/g, the discharge curve of the unit cell of this application example is shown in FIG. 7; the voltage plateau transition time point was 610.6s, and the capacity released in the nearly fully balanced phase was 551.5 As/g.

Application example two

A slurry was prepared by mixing the 3d orbital alloy sulfide positive electrode material active material for lithium sulfur batteries in example 2, a mixed conductive agent (1:1 mass ratio) of stalactite-like macroporous activated carbon (CN109607533B) and MWCNT, and a PVDF binder in a weight ratio of 75:15:10 in N-methyl-2-pyrrolidone (NMP); then uniformly depositing the slurry on the cleaned and polished aluminum collector plate; finally, the electrode was heated to 60 ℃ under-0.9 Mpa and dried for 12h to remove the NMP solvent; li foil was used as a negative electrode, and the electrolyte was 1MLiTFSI, dissolved in a mixture of 1, 3-Dioxolane (DOL) and DME (1:1 by volume), and mixed with 0.1M LiNO₃Is an electrolyte additive, a diaphragm is Celgard2325, and the CR2032 button cell is assembled in an argon atmosphere glove box; all cells were aged for several hours prior to cycling to ensure adequate electrolyte penetration into the electrodes; then, at a 2C rate, 1.7V was used as a cut-off voltage, the specific release capacity of active sulfur was 1352.7mAh/g, and the discharge curve of the battery of this application example is shown in FIG. 8.

Application example three

Assembling and testing by using a CR2032 button cell, selecting porous glass fiber (whatman) as a diaphragm and electrolyte at a volume ratio of 1mol/LNaClO4-EC/PC (1: 1); in the electrode, a sodium vanadate nanowire array is adopted as a positive electrode of the sodium ion battery (document Mater Lett,2019,237: 122-; and (3) carrying out charge and discharge tests on the assembled sodium-ion battery, wherein the test voltage range is 0.8-2.7V, the charge and discharge current density is 2A/g, the discharge capacity of the negative electrode is 213.9mAh/g when the discharge cut-off voltage is 0.8V, and the discharge curve of the battery of the application example is shown in figure 9.

Claims

1. The 3d orbital alloy sulfide material is characterized in that the chemical formula of the 3d orbital alloy sulfide material is Fe_0.5Co_xNi_yS₂Wherein 0 < x < 0.3, and x + y ═ 0.5, which exhibits a hollowed "raspberry" -like structure, said 3d orbital alloy sulfide being a single phase material.

2. The 3d orbital alloy sulfide material of claim 1, wherein Fe in the 3d orbital alloy sulfide material is only + 3.

3. The 3d orbital alloy sulfide material of claim 1, wherein the 3d orbital alloy sulfide material is Fe³⁺Form Fe_0.5The intercalator host is an intercalator compound.

4. The method for preparing 3d orbital alloy sulfide material according to any one of claims 1 to 3, wherein the sulfide material is prepared by crushing iron salt, adding nickel salt and cobalt salt, crushing, adding sulfur salt, crushing, mixing homogeneously, melting, hydrothermal reaction, and purifying at high temperature.

5. The method for preparing the 3d orbital alloy sulfide material according to claim 4, comprising the steps of:

6. The 3d orbital alloy sulfide material as defined in claim 1, which is used for producing a positive electrode for a thermal battery, a positive electrode for a lithium-sulfur battery, and a negative electrode for a sodium-ion battery.

7. The 3d orbital alloy sulfide material prepared by the preparation method of the 3d orbital alloy sulfide material according to claim 4 is used for preparing a positive electrode for a thermal battery, a positive electrode for a lithium-sulfur battery and a negative electrode for a sodium-ion battery.

8. The use according to claim 7, wherein the 3d orbital alloy sulfide material is used in a method for preparing a positive electrode for a thermal battery, comprising the steps of:

9. The use according to claim 7, wherein the 3d orbital alloy sulfide material is used in a method for preparing a positive electrode for a lithium sulfur battery by the steps of:

10. The use according to claim 7, wherein the 3d orbital alloy sulfide material is used in a method for preparing a negative electrode for a sodium-ion battery, comprising the steps of: