CN114976220A - Sulfide solid electrolyte and preparation method and application thereof - Google Patents

Sulfide solid electrolyte and preparation method and application thereof Download PDF

Info

Publication number
CN114976220A
CN114976220A CN202210712248.5A CN202210712248A CN114976220A CN 114976220 A CN114976220 A CN 114976220A CN 202210712248 A CN202210712248 A CN 202210712248A CN 114976220 A CN114976220 A CN 114976220A
Authority
CN
China
Prior art keywords
temperature
sintering
solid electrolyte
mixing
sulfide solid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210712248.5A
Other languages
Chinese (zh)
Inventor
别晓非
翟喜民
杨贺捷
何丽红
姜涛
孙焕丽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FAW Group Corp
Original Assignee
FAW Group Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by FAW Group Corp filed Critical FAW Group Corp
Priority to CN202210712248.5A priority Critical patent/CN114976220A/en
Publication of CN114976220A publication Critical patent/CN114976220A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0562—Solid materials
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/10—Halides or oxyhalides of phosphorus
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/14—Sulfur, selenium, or tellurium compounds of phosphorus
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/40—Electric properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0068—Solid electrolytes inorganic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0088—Composites
    • H01M2300/0094—Composites in the form of layered products, e.g. coatings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)

Abstract

The invention provides a sulfide solid electrolyte and a preparation method and application thereof. The solid electrolyte comprises a core, a transition layer and a coating layer, wherein the transition layer and the coating layer are sequentially connected with the core; the core is Li 7‑ x PS 6‑x Cl x X is more than or equal to 0.6 and less than or equal to 1.9; the transition layer is Li 7‑y PS 6‑ y Cl y Y is more than or equal to 0.3 and less than or equal to 0.6; the coating layer is Li 7‑z PS 6‑z Cl z And z is more than or equal to 0 and less than or equal to 0.3, and the concentration of Cl element in the coating layer is reduced in a gradient manner from the inner layer to the outer layer. The sulfide solid electrolyte provided by the invention enables the battery to have higher charge and discharge capacity, better rate performance and more excellent cycle performance.

Description

Sulfide solid electrolyte and preparation method and application thereof
Technical Field
The invention relates to the field of lithium ion batteries, and relates to a sulfide solid electrolyte set and a preparation method and application thereof.
Background
Lithium ion secondary batteries have been widely used in the fields of personal consumer electronics, electric two-wheeled vehicles, new energy vehicles, large-scale energy storage power stations, and the like. Because of its characteristics of repeated charging and discharging, high energy density, long cycle life and the like, people's daily life can not leave the lithium ion secondary battery. With the increase of energy consumption of consumer electronic products and the increase of the mileage requirement of electric vehicles, the commercial conventional lithium ion secondary battery made of liquid electrolyte at present cannot meet the desire of people on the aspects of battery energy density, safety performance and the like. In order to solve the safety performance problem of the traditional lithium ion secondary battery and improve the energy density of the battery, the novel all-solid-state lithium ion secondary battery becomes a development hotspot of the battery technology. The all-solid-state battery has the characteristics of high energy density, no explosion, no combustion and the like, and is a well-known development direction of battery technology in the future.
Compared with the traditional liquid lithium ion secondary battery, the all-solid-state battery replaces the liquid electrolyte and the diaphragm with the solid electrolyte. The solid electrolyte is uniformly mixed with the anode material or the cathode material at the anode side or the cathode side to conduct Li + The function of (1). Meanwhile, the solid electrolyte forms a solid electrolyte membrane similar to a diaphragm between the anode and the cathode, so that the anode and the cathode are physically isolated, and Li is transmitted between the anode and the cathode + The function of (1). It can be seen that the solid electrolyte is used for transporting Li in a solid battery system + The important medium of (1). However, due to the nature of the natural phase of the solid electrolyte, the solid electrolyte cannot be well infiltrated into the gaps between the particles of the positive or negative electrode material like a liquid electrolyte. Because the solid in the solid battery is difficult to form rich, stable and effective ion transport channels by the contact of the solid and the solid, the battery system is faced with low charge and discharge capacity, poor first charge and discharge efficiency, poor cycle performance and high-rate charge and discharge performanceAnd various electrochemical kinetics problems such as non-ideal.
CN113410515A discloses a sulfide solid electrolyte, a preparation method and application thereof. The sulfide solid electrolyte includes a sulfide electrolyte and a halogen oxidizer. The halogen oxidant is doped into the surface lattice of the sulfide electrolyte in a lattice-doped manner. The halogen oxidant is doped into the surface lattice of the sulfide electrolyte in a lattice doping mode. A nano-scale oxidation state coating layer may be formed on the surface layer of the sulfide electrolyte. The sulfide solid electrolyte has high internal ionic conductivity, and meanwhile, the surface oxidation state has good stability to the anode, so that the stability of contact with the anode can be improved, the cycle performance of the battery can be improved, and the service life of the battery can be prolonged. However, after the halogen oxidant is doped into the crystal lattice of the sulfide electrolyte, the ion transport performance, the air stability and other performances of the material can be changed, and a new problem is brought to a solid-state battery system.
CN110098432A discloses a preparation method and application of a carbon fiber-coated solid electrolyte material. The method comprises the following steps: 1. weighing polyacrylonitrile powder, dissolving in dimethylformamide, and magnetically stirring until the solution becomes transparent viscous and uniform; 2. transferring the electrostatic spinning solution into an injector for electrostatic spinning; 3. taking down the solid electrolyte sheet after electrostatic spinning, drying, calcining in a tubular furnace, and pre-oxidizing; 4. and carbonizing the pre-oxidized material in an argon atmosphere to obtain the carbon fiber coated solid electrolyte material. The surface of the solid electrolyte is coated by the electrostatic spinning carbon fiber, and the coating layer is tightly contacted with the solid electrolyte, so that the occurrence of element diffusion and side reaction between the anodes can be inhibited, meanwhile, the contact area of the anode material and the electrolyte can be obviously improved, the interface contact resistance is reduced, the polarization is reduced, and the discharge performance is improved. However, the coated solid electrolyte material provided by the invention has the advantages of complex synthesis process, low production rate, low capacity and high cost, and is difficult to carry out large-scale production.
CN112448025A discloses a softened solid-state electrolyte for lithium ion batteries. In an embodiment, the softened solid-state electrolyte comprises an oxide-based solid-state electrolyte, wherein at least a portion of the oxide anions in the oxide-based solid-state electrolyte are replaced with replacement anions. In another embodiment, the softened solid state electrolyte comprises a sulfide-based solid state electrolyte, wherein at least a portion of the sulfide anions in the sulfide-based solid state electrolyte are replaced with replacement anions. The replacement anion has a larger atomic radius than the oxide anion when the replacement anion replaces the oxide anion, and the replacement anion has a larger atomic radius than the sulfide anion when the replacement anion replaces the sulfide anion. Such anion-displacing solid-state electrolytes may increase the interfacial contact between the softened solid-state electrolyte and the electrode relative to a solid-state battery that includes the corresponding solid-state electrolyte but does not displace anions. However, after the anion with a larger atomic radius is used for replacement, the crystal structure of the material body is significantly changed, and then various electrochemical properties such as ionic conductivity of the material body are affected.
Therefore, how to prepare a sulfide solid electrolyte with large scale, high ionic conductivity and stable material performance is an important research direction in the field.
Disclosure of Invention
The invention aims to provide a sulfide solid electrolyte set and a preparation method and application thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention aims to provide a sulfide solid electrolyte which comprises an inner core, a transition layer and a coating layer, wherein the transition layer and the coating layer are sequentially connected with the inner core.
The core is Li 7-x PS 6-x Cl x 0.6. ltoreq. x.ltoreq.1.9, where x can be 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 or 1.9, etc., but is not limited to the values listed, and other values not listed in the numerical range are likewise suitable.
The transition layer is Li 7-y PS 6-y Cl y 0.3. ltoreq. y.ltoreq.0.6, where the value of y may be 0.3, 0.4, 0.5 or 0.6 etc., but is not limited to the values listed, which range fromOther values not listed within the enclosure are equally applicable.
The coating layer is Li 7-z PS 6-z Cl z And z is 0. ltoreq. z.ltoreq.0.3, wherein the value of z may be 0, 0.1, 0.2, 0.3 or the like, but is not limited to the enumerated values, and other unrecited values within the numerical range are also applicable, and the concentration of the Cl element in the coating layer decreases in a gradient from the inner layer to the outer layer.
The present invention provides a solid electrolyte material in which the Cl element concentration decreases in a gradient from the center to the outer surface, the Cl element concentration on the outer surface of the material particles is minimized, and the hardness of the outer surface thereof is also minimized. After the solid-state battery is subjected to pressurization treatment, the solid-state electrolyte material with the smaller hardness outer surface has a larger contact area with the anode material or the cathode material particles, so that a richer and more effective ion conduction channel is established between the anode material and the cathode material and the sulfide solid-state electrolyte particles. The sulfide solid electrolyte provided by the invention enables the battery to have higher charge and discharge capacity, better rate performance and more excellent cycle performance.
Because the gradient coating material only presents the phenomenon of lower Cl element concentration on the outer surface, the crystal structure of the gradient coating material does not present Li due to the lack of Cl element + A phenomenon that ion transport ability becomes poor. Optimized Li 7-x PS 6-x Cl x (x is more than or equal to 0.6 and less than or equal to 1.9) the solid electrolyte material still has excellent ion conductivity performance.
In a preferred embodiment of the present invention, the concentration of Cl element in the transition layer near the inner core is greater than the concentration of Cl element near the cladding layer.
Preferably, the raw material of the solid electrolyte comprises LiCl, P 2 S 5 And Li 2 S。
A second object of the present invention is to provide a method for producing a sulfide solid electrolyte according to the first object, comprising the steps of:
(1) LiCl and P are mixed 2 S 5 And Li 2 S, carrying out first mixing to obtain a raw material precursor, carrying out first high-temperature sintering on the raw material precursor, and naturally sinteringCooling to obtain a first sintering base material;
(2) the first sintering base material in the step (1) and P 2 S 5 And Li 2 And S, performing second mixing to obtain a mixed sample, performing second high-temperature sintering on the mixed sample, and naturally cooling to obtain the sulfide solid electrolyte material.
In the invention, by using non-optimized Li 7-x PS 6-x Cl x (x is more than or equal to 0.6 and less than or equal to 1.9) carrying out additive solid-phase mixing and pyrogenic sintering processes on the base material. The solid-phase mixed sintering process adopted by the gradient coated solid electrolyte material is simple and easy to implement, is suitable for large-scale industrial production, and is beneficial to improving the consistency of products.
In the preparation scheme of the invention, Li with certain Cl concentration can be obtained after one burning 7-x PS 6-x Cl x (x is more than or equal to 0.6 and less than or equal to 1.9) matrix material. The Cl element content is uniformly distributed in the matrix material particles and on the surface of the matrix material particles. In the second sintering process, the surface of the base material particles is coated with P 2 S 5 And Li 2 S raw material, under the action of thermal diffusion, Cl atoms in the base material are gradually diffused to the surface of the coating layer, and simultaneously P 2 S 5 And Li 2 Li, P, S and other elements in the S raw material are also diffused into the base material, so that Cl element concentration gradient from the interior to the outer surface of the material particles is formed. The concentration gradient is used for coating the outer surface of the material particle, the concentration of the Cl element is minimum, and therefore the hardness of the outer surface of the material particle is minimum. The material design can obviously improve the contact between the solid electrolyte material and the anode material or cathode material particles, thereby establishing abundant, stable and effective Li + An ion transport channel.
As a preferable embodiment of the present invention, LiCl and P are mixed in the first mixing in the step (1) 2 S 5 And Li 2 The molar ratio of S is 2 m: 1: (7-2m), 0.6. ltoreq. m.ltoreq.1.9, wherein m may have a value of 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 or 1.9, etc., but is not limited to the recited values, and other values not recited in the numerical range are also applicable.
In a preferred embodiment of the present invention, the first mixing in step (1) is performed at a rate of 500 to 700rpm, wherein the rate may be 500rpm, 520rpm, 540rpm, 560rpm, 580rpm, 600rpm, 620rpm, 640rpm, 660rpm, 680rpm, 700rpm, or the like, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned value range are also applicable.
Preferably, the time for the first mixing in step (1) is 20-25 min, wherein the time can be 20min, 21min, 22min, 23min, 24min or 25min, etc., but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.
Preferably, the atmosphere of the first high-temperature sintering in the step (1) is an inert atmosphere.
Preferably, the temperature increase rate of the first high-temperature sintering in step (1) is 4-6 ℃/min, wherein the temperature increase rate can be 4 ℃/min, 5 ℃/min or 6 ℃/min, etc., but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.
Preferably, the constant temperature of the first high-temperature sintering in step (1) is 500-600 ℃, wherein the constant temperature may be 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃ or 600 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the constant temperature holding time of the first high temperature sintering in the step (1) is 5-10 h, wherein the constant temperature holding time can be 5h, 6h, 7h, 8h, 9h or 10h, etc., but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferable embodiment of the present invention, in the second mixing in the step (2), the first sintered base material and P are mixed 2 S 5 And Li 2 The molar ratio of S is 1: (0.001-0.01): (0.001-0.1), wherein the molar ratio may be 1:0.001:0.001, 1:0.001:0.1, 1:0.001:0.01, 1:0.01:0.001, 1:0.01:0.01, or 1:0.01:0.1, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.
In a preferred embodiment of the present invention, the second mixing rate in step (2) is 500 to 700rpm, wherein the second mixing rate may be 500rpm, 520rpm, 540rpm, 560rpm, 580rpm, 600rpm, 620rpm, 640rpm, 660rpm, 680rpm, 700rpm, or the like, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned value range are also applicable.
Preferably, the time for the second mixing in step (2) is 20-25 min, wherein the time can be 20min, 21min, 22min, 23min, 24min or 25min, etc., but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.
Preferably, the atmosphere of the second high-temperature sintering in the step (2) is an air atmosphere.
Preferably, the temperature increase rate of the second high temperature sintering in step (2) is 15 to 25 ℃/min, wherein the temperature increase rate can be 15 ℃/min, 16 ℃/min, 17 ℃/min, 18 ℃/min, 19 ℃/min, 20 ℃/min, 21 ℃/min, 22 ℃/min, 23 ℃/min, 24 ℃/min or 25 ℃/min, and the like, but is not limited to the enumerated values, and other values in the numerical range are also applicable.
Preferably, the constant temperature of the second high temperature sintering in step (2) is 300-600 ℃, wherein the constant temperature may be 300 ℃, 330 ℃, 360 ℃, 390 ℃, 420 ℃, 450 ℃, 480 ℃, 510 ℃, 540 ℃, 570 ℃ or 600 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the constant temperature holding time of the second high temperature sintering in the step (2) is 2-6 h, wherein the constant temperature holding time can be 2h, 3h, 4h, 5h or 6h, etc., but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferred embodiment of the present invention, the temperature after the natural cooling in the step (1) is less than 50 ℃, wherein the temperature may be 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃ or 49 ℃ or the like, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.
Preferably, the temperature after the natural cooling in the step (2) is less than 50 ℃, wherein the temperature can be 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃ or 49 ℃ and the like, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferred technical scheme of the invention, the preparation method comprises the following steps:
(1) LiCl and P are mixed 2 S 5 And Li 2 S, carrying out first mixing at the speed of 500-700 rpm for 20-25 min to obtain a raw material precursor, carrying out first high-temperature sintering on the raw material precursor at the temperature rise speed of 4-6 ℃/min, at the constant temperature of 500-600 ℃ and at the constant temperature for 5-10 h, and naturally cooling to the temperature of 500-700 rpm<Obtaining a first sintering base material at 50 ℃;
(2) the first sintering base material in the step (1) and P 2 S 5 And Li 2 S, performing second mixing at the speed of 500-700 rpm for 20-25 min to obtain a mixed sample, performing second high-temperature sintering on the mixed sample at the temperature rising speed of 15-25 ℃/min, at the constant temperature of 300-600 ℃ and at the constant temperature for 2-6 h, and naturally cooling to the temperature<Obtaining the sulfide solid electrolyte material at 50 ℃.
The second purpose of the invention is to provide the application of the sulfide solid electrolyte as mentioned in the first purpose, and the sulfide solid electrolyte is applied to the field of lithium ion batteries.
Compared with the prior art, the invention has the following beneficial effects:
the concentration of the element Cl in the solid electrolyte of the present invention decreases in a gradient from the center to the outer surface. The Cl element concentration on the outer surface of the material particles is minimal and the hardness of the outer surface is also minimal. After the solid-state battery is subjected to pressurization treatment, the solid-state electrolyte material with the smaller hardness outer surface has a larger contact area with the anode material or the cathode material particles, so that richer and more effective ion conduction channels are established between the anode material, the cathode material and the solid-state electrolyte particles. The solid electrolyte provided by the invention enables the battery to have higher charge and discharge capacity, better rate performance and more excellent cycle performance, wherein the first charge and discharge reversible specific capacity can reach more than 180mAh/g, the 2C rate capacity retention rate can reach more than 80%, and the cycle performance can exceed 150 cycles
Drawings
FIG. 1 is an SEM photograph of a sulfide solid electrolyte in example 1 of the present invention.
Fig. 2 is an XRD profile of the sulfide solid state electrolyte material in example 1 of the present invention and comparative example 1.
Fig. 3 is a charge and discharge curve of a sulfide solid electrolyte in a solid-state battery in example 1 of the present invention and comparative example 1.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl, 22.227gP 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 20min at the speed of 500rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 5 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.04gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, the mixture is mixed for 20min at the speed of 500rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and put into an atmosphere sintering furnace, and the mixed sample is heated at the speed of 20 ℃/min, at the constant temperature of 500 ℃ and for 2h under the nitrogen atmosphereSecond high-temperature sintering, after finishing constant-temperature heat preservation, leaving the sample in an atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining the sulfide solid electrolyte material at 50 ℃. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
The SEM image of the sulfide solid electrolyte in this example is shown in FIG. 1.
Example 2
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl and 22.227gP are mixed 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 25min at the speed of 700rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 4 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.04gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, second mixing is carried out for 25min at the speed of 700rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and is placed into an atmosphere sintering furnace, second high-temperature sintering is carried out on the mixed sample under the nitrogen atmosphere, the temperature rising speed is 15 ℃/min, the constant temperature is 300 ℃, the constant temperature heat preservation time is 2h, after the constant temperature heat preservation is finished, the sample is left in the atmosphere sintering furnace to be naturally cooled to the hearth temperature<Obtaining the sulfide solid electrolyte material at 50 ℃. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
Example 3
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl, 22.227gP 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 22min at the speed of 600rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise rate of 6 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.04gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, second mixing is carried out for 25min at the speed of 600rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and placed into an atmosphere sintering furnace, second high-temperature sintering is carried out on the mixed sample under the nitrogen atmosphere at the temperature rising speed of 25 ℃/min, the constant temperature of 600 ℃ and the constant temperature preservation time of 2h, and after the constant temperature preservation is finished, the sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining the sulfide solid electrolyte material at 50 ℃. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
Example 4
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl and 22.227gP are mixed 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 20min at the speed of 500rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 5 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.08gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, second mixing is carried out for 20min at the speed of 500rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and put into an atmosphere sintering furnace, second high-temperature sintering is carried out on the mixed sample under the nitrogen atmosphere at the temperature rising speed of 20 ℃/min, the constant temperature of 500 ℃ and the constant temperature preservation time of 2h, and after the constant temperature preservation is finished, the sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining the sulfide solid electrolyte material at 50 ℃. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
Example 5
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl, 22.227gP 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 20min at the speed of 500rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 5 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.04gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, second mixing is carried out for 20min at the speed of 500rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and put into an atmosphere sintering furnace, second high-temperature sintering is carried out on the mixed sample under the nitrogen atmosphere at the temperature rising speed of 20 ℃/min, the constant temperature of 500 ℃ and the constant temperature preservation time of 4h, and after the constant temperature preservation is finished, the sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining the sulfide solid electrolyte material at 50 ℃. Solid-state electrolysis of sintered sulfideAnd taking the material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
Example 6
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl and 22.227gP are mixed 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 20min at the speed of 500rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 5 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) 50g of the first sintered base material of the step (1) and 0.04gP 2 S 5 And 0.3gLi 2 S is added into a high-speed mixer, second mixing is carried out for 20min at the speed of 500rpm to obtain a mixed sample, the mixed sample is poured into a ceramic crucible and put into an atmosphere sintering furnace, second high-temperature sintering is carried out on the mixed sample under the nitrogen atmosphere at the temperature rising speed of 20 ℃/min, the constant temperature of 400 ℃ and the constant temperature preservation time of 2h, and after the constant temperature preservation is finished, the sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining the sulfide solid electrolyte material at 50 ℃. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
Example 7
This example is prepared by mixing 8.478gLiCl and 22.227gP in step (1) 2 S 5 And 22.975gLi 2 S is replaced by 4.239gLiCl and 22.227gP 2 S 5 And 27.57gLi 2 Except for S, the other conditions were the same as in example 1.
Example 8
This example is prepared by mixing 8.478gLiCl and 22.227gP in step (1) 2 S 5 And 22.975gLi 2 S is replaced by 16.956g LiCl,22.227gP 2 S 5 And 13.785gLi 2 Except for S, the other conditions were the same as in example 1.
Comparative example 1
The embodiment provides a preparation method of a sulfide solid electrolyte, which comprises the following steps:
(1) 8.478gLiCl and 22.227gP are mixed 2 S 5 And 22.975gLi 2 S is added into a high-speed mixer, first mixing is carried out for 20min at the speed of 500rpm to obtain a raw material precursor, the raw material precursor is transferred into a ceramic crucible and is placed into an atmosphere sintering furnace, first high-temperature sintering is carried out on the raw material precursor for 8h at the temperature rise speed of 5 ℃/min, the constant temperature of 550 ℃ and the constant temperature preservation time under the nitrogen atmosphere, after the constant-temperature sintering is finished, a sample is left in the atmosphere sintering furnace to be naturally cooled to the temperature of a hearth<Obtaining a first sintering base material at 50 ℃, and taking the material out of a sintering furnace under the protection of nitrogen atmosphere;
(2) and (2) pouring the first sintering base material obtained in the step (1) into a ceramic crucible, putting the ceramic crucible into an atmosphere sintering furnace, performing second high-temperature sintering on the first sintering base material at the temperature rising speed of 20 ℃/min, at the constant temperature of 500 ℃ and for the constant-temperature heat preservation time of 2 hours in the nitrogen atmosphere, and after the constant-temperature heat preservation is finished, leaving the sample in the atmosphere sintering furnace to be naturally cooled to the hearth temperature of less than 50 ℃ to obtain the sulfide solid electrolyte material. And taking the sintered sulfide solid electrolyte material out of the hearth under the protection of nitrogen atmosphere to finish sintering.
The XRD curves of the sulfide solid electrolytes prepared in example 1 and this comparative example are shown in fig. 2, and the charge and discharge curves of the prepared sulfide solid batteries are shown in fig. 3.
FIG. 2 is an XRD curve of a gradient coated sulfide solid state electrolyte material; the gradient-clad optimized solid state electrolyte provided by the present invention has the same crystal structure as the unoptimized solid state electrolyte material, indicating that P 2 S 5 And Li 2 The S coating does not change the crystal structure of the material and does not influence the ionic conductivity of the material.
Fig. 3 is a charge-discharge curve of the sulfide solid electrolyte obtained in example 1 and comparative example 1 in a solid-state battery. The sulfide solid electrolyte optimized by gradient coating can provide higher capacity and smaller polarization effect after being assembled into a solid battery. This phenomenon can be attributed to the excellent fusibility between the particles of the positive electrode material, and the abundant, stable and effective lithium ion transport paths exist between the particles of the material.
Comparative example 2
This comparative example was conducted without addition of Li in the second mixing of step (2) 2 Except for S, the other conditions were the same as in example 1.
Comparative example 3
This comparative example was conducted without adding P in the second mixing of step (2) 2 S 5 Otherwise, the conditions were the same as in example 1.
The sulfide solid-state electrolytes of examples 1 to 8 and comparative examples 1 to 3 were assembled into batteries, and the batteries were tested for ion conductivity, rate capability and cycle performance, and the test results are shown in table 1.
The method for testing the lithium ion conductivity comprises the following steps: in an argon glove box, 100mg of the solid electrolyte powder was weighed, placed in an insulating outer cylinder, pressure-molded at a pressure of 300MPa, and subjected to ac impedance spectroscopy using a die battery. The test conditions were: the testing pressure is 300MPa, and the frequency is 3.5MHz-0.1 Hz. The test data calculates the ionic conductivity of the electrolyte material according to the impedance value and the arrhenius formula.
The method for testing the multiplying power performance comprises the following steps: a mold battery which is composed of 811 ternary material as a positive electrode, Li/In alloy as a negative electrode and the sulfide solid electrolyte is assembled In an argon glove box and is subjected to 0.1C constant current charging and discharging and 2C constant current charging and discharging tests by using a constant current charging and discharging tester. And dividing the 2C constant-current discharge capacity by the 0.1C constant-current discharge capacity to obtain the capacity retention rate percentage as the rate performance. (ii) a
The test method of the cycle performance comprises the following steps: a mold battery composed of 811 ternary material as a positive electrode, Li/In alloy as a negative electrode and the sulfide solid electrolyte was assembled In an argon glove box, and subjected to 1/3C constant current charge and discharge test using a constant current charge and discharge tester. After 100 constant current charge-discharge cycles, the percentage of the residual reversible capacity to the first capacity is the cycle performance.
TABLE 1
Figure BDA0003707255650000151
From the above table we can get:
(1) li added during the second sintering 2 S and P 2 S 5 The solid electrolyte provided by the scheme of the invention can establish a good lithium ion conduction path between a solid state and a solid surface.
(2) In the second sintering process, the sintering temperature plays a very important role in realizing the Cl element gradient coating target.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (10)

1. The sulfide solid electrolyte is characterized by comprising an inner core, a transition layer and a coating layer, wherein the transition layer and the coating layer are sequentially connected with the inner core;
the core is Li 7-x PS 6-x Cl x ，0.6≤x≤1.9；
The transition layer is Li 7-y PS 6-y Cl y ，0.3≤y≤0.6；
The coating layer is Li 7-z PS 6-z Cl z And z is more than or equal to 0 and less than or equal to 0.3, and the concentration of Cl element in the coating layer is reduced in a gradient manner from the inner layer to the outer layer.
2. The sulfide solid state electrolyte of claim 1, wherein a concentration of the element Cl in the transition layer near the core is greater than a concentration of the element Cl near the cladding layer;
preferably, the raw material of the solid electrolyte comprises LiCl, P 2 S 5 And Li 2 S。
3. A production method of the sulfide solid electrolyte according to claim 1 or 2, comprising the steps of:
(1) LiCl and P are mixed 2 S 5 And Li 2 S, carrying out first mixing to obtain a raw material precursor, carrying out first high-temperature sintering on the raw material precursor, and naturally cooling to obtain a first sintering base material;
(2) the first sintering base material in the step (1) and P 2 S 5 And Li 2 And S, performing second mixing to obtain a mixed sample, performing second high-temperature sintering on the mixed sample, and naturally cooling to obtain the sulfide solid electrolyte material.
4. The method according to claim 3, wherein LiCl, P in the first mixing of step (1) 2 S 5 And Li 2 The molar ratio of S is 2 m: 1: (7-2m), wherein m is more than or equal to 0.6 and less than or equal to 1.9.
5. The method according to claim 3 or 4, wherein the first mixing in step (1) is performed at a rate of 500 to 700 rpm;
preferably, the time for the first mixing in the step (1) is 20-25 min;
preferably, the atmosphere of the first high-temperature sintering in the step (1) is an inert atmosphere;
preferably, the temperature rise rate of the first high-temperature sintering in the step (1) is 4-6 ℃/min;
preferably, the constant temperature of the first high-temperature sintering in the step (1) is 500-600 ℃;
preferably, the constant temperature heat preservation time of the first high temperature sintering in the step (1) is 5-10 h.
6. The production method according to any one of claims 3 to 5, wherein in the second mixing in step (2), the first sintered base material, P, is mixed with 2 S 5 And Li 2 The molar ratio of S is 1: (0.001-0.01): (0.001-0.1).
7. The method according to any one of claims 3 to 6, wherein the second mixing in step (2) is carried out at a rate of 500 to 700 rpm;
preferably, the time of the second mixing in the step (2) is 20-25 min;
preferably, the atmosphere of the second high-temperature sintering in the step (2) is air atmosphere;
preferably, the temperature rise rate of the second high-temperature sintering in the step (2) is 15-25 ℃/min;
preferably, the constant temperature of the second high-temperature sintering in the step (2) is 300-600 ℃;
preferably, the constant-temperature heat preservation time of the second high-temperature sintering in the step (2) is 2-6 h.
8. The method of any one of claims 3-7, wherein the temperature after the natural cooling of step (1) is <50 ℃;
preferably, the temperature after said natural cooling of step (2) is <50 ℃.
9. The method according to any one of claims 3 to 8, characterized in that it comprises the following steps:
(1) LiCl and P are mixed 2 S 5 And Li 2 S, carrying out first mixing at the speed of 500-700 rpm for 20-25 min to obtain a raw material precursor, carrying out first high-temperature sintering on the raw material precursor at the temperature rise speed of 4-6 ℃/min, at the constant temperature of 500-600 ℃ and at the constant temperature for 5-10 h, and naturally cooling to the temperature of 500-700 rpm<Obtaining a first sintering base material at 50 ℃;
(2) the first sintering base material in the step (1) and P 2 S 5 And Li 2 S is advancedPerforming second mixing at the speed of 500-700 rpm for 20-25 min to obtain a mixed sample, performing second high-temperature sintering on the mixed sample at the temperature rise speed of 15-25 ℃/min, at the constant temperature of 300-600 ℃ and at the constant temperature for 2-6 h, and naturally cooling to the temperature<Obtaining the sulfide solid electrolyte material at 50 ℃.
10. Use of the sulfide solid electrolyte according to claim 1 or 2 in the field of lithium ion batteries.
CN202210712248.5A 2022-06-22 2022-06-22 Sulfide solid electrolyte and preparation method and application thereof Pending CN114976220A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210712248.5A CN114976220A (en) 2022-06-22 2022-06-22 Sulfide solid electrolyte and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210712248.5A CN114976220A (en) 2022-06-22 2022-06-22 Sulfide solid electrolyte and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN114976220A true CN114976220A (en) 2022-08-30

Family

ID=82965943

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210712248.5A Pending CN114976220A (en) 2022-06-22 2022-06-22 Sulfide solid electrolyte and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN114976220A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117594869A (en) * 2024-01-17 2024-02-23 中国第一汽车股份有限公司 Sulfide and preparation method thereof, solid electrolyte, all-solid-state battery and electric equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117594869A (en) * 2024-01-17 2024-02-23 中国第一汽车股份有限公司 Sulfide and preparation method thereof, solid electrolyte, all-solid-state battery and electric equipment
CN117594869B (en) * 2024-01-17 2024-05-14 中国第一汽车股份有限公司 Sulfide and preparation method thereof, solid electrolyte, all-solid-state battery and electric equipment

Similar Documents

Publication Publication Date Title
CN107464938B (en) Molybdenum carbide/carbon composite material with core-shell structure, preparation method thereof and application thereof in lithium air battery
CN112928246B (en) Composite material, preparation method and application thereof
CN111484247A (en) Glass positive electrode material and preparation method and application thereof
CN114976220A (en) Sulfide solid electrolyte and preparation method and application thereof
CN114497707A (en) High-performance low-cost composite solid electrolyte and preparation method and application thereof
CN103515600A (en) Ti3SiC2 and carbon composite modified LiFePO4 lithium ion battery anode material and preparation method thereof
CN115312736B (en) Preparation method of Si@TiN-asphalt composite anode material
CN114420927B (en) Negative electrode material, preparation method thereof and negative electrode sheet
CN115172681A (en) Preparation method and application of lithium ferric manganese phosphate cathode material
CN114420932B (en) High-performance glass-ceramic electrode material containing variable-valence metal ion oxide, and preparation method and application thereof
CN109786709A (en) A kind of ferroferric oxide/carbon composite negative electrode material and its preparation method and application
CN111048776B (en) Shape-adjustable cubic cobaltosic oxide, preparation method and lithium ion battery
CN114784233A (en) Negative electrode active material and preparation method and application thereof
CN114361577A (en) Pure cubic phase nano lithium gallium lanthanum zirconium oxygen powder and preparation method and application thereof
CN108807889B (en) Preparation method and application of porous iron-doped vanadium oxide electrode material
CN114824271B (en) Anode material and preparation method thereof, lithium battery anode and preparation method thereof, and lithium battery
CN114583137B (en) Method for modifying carbon surface by sulfur doped phosphorus and application thereof
CN108862403A (en) A kind of preparation method and applications of cobalt acid zinc nanometer sheet material
CN114956182B (en) Micron rod-shaped niobium tungsten oxide and preparation method and application thereof
CN108550851B (en) Method for preparing lithium battery anode material by calcining organic silicide
CN118198244A (en) Method for preparing graphite anode material
CN118315571A (en) Nitrogen-doped molybdenum oxide coated graphite negative electrode material and preparation method thereof
CN115911335A (en) Si-Sn-TiC/C/asphalt composite material and preparation method and application thereof
CN117038875A (en) Method for coating surface of silicon-carbon composite anode material with nitrogen-doped carbon
CN116364889A (en) Preparation method and application of organic polymer-sodium titanate material

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination