CN118325087A

CN118325087A - Polymer, preparation method thereof, solid electrolyte, battery and electricity utilization device

Info

Publication number: CN118325087A
Application number: CN202410540818.6A
Authority: CN
Inventors: 陈永胜; 高贺; 田二丽; 孟祥宇; 周琪; 翟旭亮; 赵壮; 孙永健; 周馨悦; 姜迪
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Filing date: 2024-04-30
Publication date: 2024-07-12

Abstract

The application provides a polymer and a preparation method thereof, a solid electrolyte, a battery and an electric device, and belongs to the technical field of solid lithium metal batteries. The preparation method of the polymer comprises the steps of reacting a first mixture containing elemental sulfur, a first alkaline compound and a first solvent at a temperature of 25-90 ℃ for 0.1-3 hours to obtain a second mixture, mixing the second alkaline compound, diamine, anhydrous chloroform and the second mixture, and reacting at a temperature of 25-120 ℃ for 1-20 hours to obtain a third mixture. The preparation method of the polymer can prepare the polythiourea with higher molecular weight, the polythiourea can be used for preparing solid electrolyte, the thiourea group and lithium ions form tight combination through synergistic electrostatic action and hydrogen bonding action, the dissolution of lithium salt in a polymer matrix is promoted, the lithium ions are combined, an ion conduction channel is constructed, and the movement of the lithium ions is assisted in a mode of decoupling with the movement of a polymer chain segment.

Description

Polymer, preparation method thereof, solid electrolyte, battery and electricity utilization device

Technical Field

The application relates to the technical field of solid lithium metal batteries, in particular to a polymer, a preparation method thereof, a solid electrolyte, a battery and an electric device.

Background

In recent years, all-solid-state lithium metal batteries have attracted wide attention due to the advantages of high energy density, high safety and the like, but the conventional liquid electrolyte has the risks of easy leakage, inflammability, explosiveness and the like, and is difficult to use in all-solid-state lithium metal batteries. The polymer electrolyte has the advantages of high (electrochemical) stability, processability and the like, and is one of key materials for realizing the all-solid-state lithium metal battery. Polymer electrolytes, which mainly include lithium salt-polymer blend systems and single lithium ion conducting polymer systems, offer a safe solution for future solid state high energy density batteries. The limitation of low room temperature conductivity and limitation of high-efficiency lithium ion transmission becomes one of the main bottlenecks for developing all-solid-state lithium metal batteries.

Disclosure of Invention

The application provides a polymer, a preparation method thereof, a solid electrolyte, a battery and an electric device, which can improve ion conductivity and lithium ion transmission efficiency.

Embodiments of the present application are implemented as follows:

In a first aspect, the present examples provide a method of preparing a polymer comprising: reacting a first mixture containing elemental sulfur, a first alkaline compound and a first solvent at a temperature of 25-90 ℃ for 0.1-3 hours to obtain a second mixture, mixing the second alkaline compound, diamine, anhydrous chloroform and the second mixture, and reacting at a temperature of 25-120 ℃ for 1-20 hours to obtain a third mixture.

Wherein the structural formula of the diamine is as follows:

R ₁ is selected from O, C _1～20 saturated alkyl or C _1～20 aliphatic ether group.

In the technical scheme, the preparation method of the polymer comprises two steps of reaction, wherein the first step is to react elemental sulfur with a first alkaline compound to open a sulfur ring, and the second step is to polymerize chain sulfur with a second alkaline compound, diamine and anhydrous chloroform to prepare the polythiourea with higher molecular weight, and the preparation method of the polymer has the advantages of improved yield and no toxic and harmful substances introduced in the polymerization process of the polymer.

The polythiourea can be used for preparing solid electrolyte, the thiourea groups and lithium ions form tight combination through synergistic electrostatic action and hydrogen bond action, the dissolution of lithium salt in a polymer matrix is promoted, lithium ions are combined, an ion conduction channel is constructed, and the movement of lithium ions is assisted in a mode of decoupling with the movement of a polymer chain segment.

With reference to the first aspect, in a first possible example of the first aspect of the present application, the above-mentioned polymer preparation method satisfies at least one of the following conditions:

a. The mole ratio of the elemental sulfur to the diamine is 1-6:1.

B. The molar ratio of the first basic compound to the diamine is 1-6:1.

C. the molar ratio of the second basic compound to the diamine is 1-2:1.

D. The molar ratio of the anhydrous chloroform to the diamine is 1-6:1.

E. The volume molar ratio of the first solvent to the diamine is 0.1 mL-1 mL:1mol.

In the above examples, by making each raw material in the production method of the polymer satisfy at least one of the above conditions, the produced polythiourea is higher in molecular weight and higher in yield.

With reference to the first aspect, in a second possible example of the first aspect of the present application, the diamine includes N is an integer of 1 to 9.

With reference to the first aspect, in a third possible example of the first aspect of the present application, the diamine includesN is an integer of 1 to 9.

In the above examples, the polythiourea molecular weight obtained by the production method of the polymer of the present application is higher by allowing the diamine to satisfy the above structure.

With reference to the first aspect, in a fourth possible example of the first aspect of the present application, the above-mentioned first basic compound includes any one or more of calcium hydroxide, potassium tert-butoxide, sodium hydroxide, and potassium carbonate;

The second alkaline compound includes any one or more of calcium hydroxide, potassium tert-butoxide, sodium hydroxide and potassium carbonate.

With reference to the first aspect, in a fifth possible example of the first aspect of the present application, the first solvent includes any one or more of pyridine, N-dimethylacetamide, t-butanol, 1, 4-dioxane, and dimethylsulfoxide.

In combination with the first aspect, in a sixth possible example of the first aspect of the present application, the preparation method of the polymer further includes settling the third mixture in the second solvent, filtering to obtain a solid, washing the solid with the third solvent, and centrifuging to obtain the polythiourea.

In the above examples, the preparation method of the present application can remove or reduce impurities doped in the polythiourea by means of sedimentation, filtration and washing, thereby obtaining purer polythiourea.

With reference to the first aspect, in a seventh possible example of the first aspect of the present application, the second solvent includes any one or more of water, cyclohexane, n-hexane, and methanol.

In the above example, the polythiourea was allowed to settle by selecting the above solvent as the second solvent, and thus could be collected by filtration.

With reference to the first aspect, in an eighth possible example of the first aspect of the present application, a ratio of a volume of the second solvent to a volume of the first solvent is equal to or greater than 1.

In the above example, by making the ratio of the volume of the second solvent to the volume of the first solvent be 1 or more, the polythiourea dissolved in the first solvent can be precipitated.

With reference to the first aspect, in a ninth possible example of the first aspect of the present application, the third solvent includes methanol and/or ethanol.

In the above examples, the polythiourea is insoluble in methanol and/or ethanol, other small molecules without polymerization and byproducts can be soluble in methanol and/or ethanol, and the impurities on the surface of the polythiourea can be removed by washing the polythiourea with methanol and/or ethanol, so that purer polythiourea is obtained.

In a second aspect, the present examples provide a polymer produced according to the above-described method of producing a polymer.

In the technical scheme, the polymer provided by the application has higher molecular weight, can be used for preparing solid electrolyte, forms tight combination through synergistic electrostatic action and hydrogen bonding action between thiourea groups and lithium ions, promotes dissolution of lithium salt in a polymer matrix, combines lithium ions, constructs an ion conduction channel, and assists movement of lithium ions in a mode of decoupling movement of polymer chain segments.

In a third aspect, the present examples provide a solid state electrolyte comprising a lithium salt and the polymer described above.

In the technical scheme, the solid electrolyte provided by the application has higher ion conductivity and lithium ion transmission efficiency.

With reference to the third aspect, in a first possible example of the third aspect of the present application, the lithium salt accounts for 1wt% to 80wt% of the total mass of the solid electrolyte.

With reference to the third aspect, in a second possible example of the third aspect of the present application, the lithium salt includes any one or more of lithium perchlorate, lithium bis (trifluoromethylsulfonyl) imide, lithium tetrafluoroborate, and lithium bis difluorosulfimide.

In a fourth aspect, an example of the application provides a battery comprising the solid electrolyte described above.

In a fifth aspect, an example of the application provides an electrical device comprising a battery as described above.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows ion conductivities of solid electrolytes prepared in examples 1 to 3 of the present application.

Detailed Description

Embodiments of the present application will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present application and should not be construed as limiting the scope of the present application. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The following is a specific description of a polymer, a preparation method thereof, a solid electrolyte, a battery and an electric device according to an embodiment of the present application:

the application provides a preparation method of a polymer, which comprises the following steps:

S1, pretreatment

Since the process for producing the polymer of the present application is carried out in an anhydrous environment, it is necessary to dry the reaction raw materials and the reaction vessel.

The pretreatment comprises the steps of drying and dehumidifying the reaction raw materials, and drying the reaction kettle and the stirring device.

Alternatively, the drying temperature is 90℃to 150 ℃.

S2, polymerization

Firstly introducing inert gas into a reaction kettle to discharge air or oxygen in the reaction kettle, then adding elemental sulfur, a first alkaline compound and a first solvent into the reaction kettle, starting a stirring device, reacting for 0.1-3 h at 25-90 ℃ to prepare a second mixture, adding a second alkaline compound, diamine and anhydrous chloroform into the reaction kettle, and reacting for 1-20 h at 25-120 ℃ to prepare a third mixture.

The inert gas includes any one or more of nitrogen, helium, argon, and xenon.

As an example, the inert gas may be nitrogen, helium, argon, or xenon alone, or may be a mixed gas of nitrogen and helium, or may be a mixed gas of helium and argon, or may be a mixed gas of argon and xenon, or may be a mixed gas of nitrogen and argon, or may be a mixed gas of helium and xenon, or may be a mixed gas of helium, argon, and xenon, or may be a mixed gas of nitrogen, helium, and argon.

The first basic compound includes an organic basic compound and an inorganic basic compound.

Alternatively, the inorganic basic compound includes a hydroxide and a metal salt.

Optionally, the first basic compound comprises any one or more of calcium hydroxide, potassium tert-butoxide, sodium hydroxide, and potassium carbonate.

As an example, the first basic compound may be calcium hydroxide, potassium tert-butoxide, sodium hydroxide or potassium carbonate alone, or may be a mixture of potassium tert-butoxide and sodium tert-butoxide, or may be a mixture of calcium hydroxide and sodium hydroxide, or may be a mixture of calcium hydroxide and potassium tert-butoxide, or may be a mixture of sodium tert-butoxide and sodium hydroxide, or may be a mixture of calcium hydroxide, potassium tert-butoxide and sodium tert-butoxide, or may be a mixture of potassium tert-butoxide, sodium tert-butoxide and sodium hydroxide, or may be a mixture of calcium hydroxide, potassium tert-butoxide, sodium tert-butoxide and sodium hydroxide.

The first solvent includes any one or more of pyridine, N-dimethylacetamide, t-butanol, 1, 4-dioxane, and dimethylsulfoxide.

As an example, the first solvent may be pyridine, N-dimethylacetamide, t-butanol, 1, 4-dioxane or dimethylsulfoxide alone, or may be a mixture of pyridine and N, N-dimethylacetamide, or may be a mixture of N, N-dimethylacetamide and t-butanol, or may be a mixture of 1, 4-dioxane and dimethylsulfoxide, or may be a mixture of pyridine and t-butanol, or may be a mixture of 1, 4-dioxane and N, N-dimethylacetamide, or may be a mixture of pyridine and dimethylsulfoxide, or may be a mixture of pyridine, N-dimethylacetamide and t-butanol, or may be a mixture of t-butanol, 1, 4-dioxane and dimethylsulfoxide, or may be a mixture of pyridine, N-dimethylacetamide, t-butanol and dimethylsulfoxide.

The second basic compound includes an organic basic compound and an inorganic basic compound.

Optionally, the second alkaline compound comprises any one or more of calcium hydroxide, potassium tert-butoxide, sodium hydroxide, and potassium carbonate.

As an example, the second basic compound may be calcium hydroxide, potassium tert-butoxide, sodium hydroxide or potassium carbonate alone, or may be a mixture of potassium tert-butoxide and sodium tert-butoxide, or may be a mixture of calcium hydroxide and sodium hydroxide, or may be a mixture of calcium hydroxide and potassium tert-butoxide, or may be a mixture of sodium tert-butoxide and sodium hydroxide, or may be a mixture of calcium hydroxide, potassium tert-butoxide and sodium tert-butoxide, or may be a mixture of potassium tert-butoxide, sodium tert-butoxide and sodium hydroxide, or may be a mixture of calcium hydroxide, potassium tert-butoxide, sodium tert-butoxide and sodium hydroxide.

The first basic compound and the second basic compound may be the same or different.

The structural formula of the diamine is as follows:

Alternatively, the diamine comprises N is an integer of 1 to 9.

Alternatively, the diamine comprisesN is an integer of 1 to 9.

By allowing the diamine to satisfy the above structure, the polythiourea produced by the production method of the polymer of the present application has a relatively high molecular weight.

Alternatively, the diamine has the structural formula:

The mole ratio of the elemental sulfur to the diamine is 1-6:1.

As examples, the molar ratio of elemental sulfur to diamine may be 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1.

The molar ratio of the first basic compound to the diamine is 1-6:1.

As an example, the molar ratio of the first basic compound to the diamine may be 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1.

The molar ratio of the second basic compound to the diamine is 1-2:1.

As an example, the molar ratio of the second basic compound to the diamine may be 1:1, 1.2:1, 1.5:1, 1.8:1, or 2:1.

The molar ratio of the anhydrous chloroform to the diamine is 1-6:1.

As examples, the molar ratio of anhydrous chloroform to diamine may be 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1.

The volume molar ratio of the first solvent to the diamine is 0.1 mL-1 mL:1mol.

As examples, the volumetric molar ratio of the first solvent to diamine may be 0.1mL:1mol, 0.2mL:1mol, 0.5mL:1mol, 0.8mL:1mol, or 1mL:1mol.

By allowing each raw material in the production method of the polymer to satisfy at least one of the above conditions, the produced polythiourea is higher in molecular weight and higher in yield.

As an example, the reaction temperature at which the second mixture is prepared may be 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, or 90 ℃, and the reaction time at which the second mixture is prepared may be 0.1h, 0.2h, 0.5h, 0.8h, 1h, 1.5h, 2h, 2.5h, or 3h.

It should be noted that the reaction temperature of the second mixture cannot be higher than 90 ℃, so that the coking of elemental sulfur is avoided to generate side reactions.

As an example, the reaction temperature at which the third mixture is prepared may be 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃,100 ℃, 105 ℃, 110 ℃, 115 ℃, or 120 ℃, and the reaction time at which the second mixture is prepared may be 1h, 2h, 5h, 8h, 10h, 15h, or 20h.

In the polymerization step, two steps of reactions are carried out, wherein the first step is to enable elemental sulfur and a first alkaline compound to react, so that a sulfur ring is opened, and the second step is to enable chain sulfur, a second alkaline compound, diamine and anhydrous chloroform to carry out polymerization reaction, so that polythiourea with higher molecular weight is prepared, and the yield of the preparation method of the polymer is improved, and no toxic and harmful substances are introduced in the polymerization process of the polymer.

S3, purifying

And (3) settling the third mixture in a second solvent, filtering to obtain a solid, washing the solid by adopting the third solvent, and centrifuging to obtain the polythiourea.

The second solvent includes any one or more of water, cyclohexane, n-hexane, and methanol.

By selecting the above solvent as the second solvent, the polythiourea is allowed to settle, so that it can be collected by filtration.

As an example, the second solvent may be water, cyclohexane, n-hexane, or methanol alone, or may be a mixture of cyclohexane and n-hexane, or may be a mixture of n-hexane and methanol, or may be a mixture of cyclohexane, n-hexane, and methanol.

The third solvent comprises methanol and/or ethanol.

The polythiourea can not be dissolved in methanol and/or ethanol, other small molecules without polymerization and byproducts can be dissolved in the methanol and/or the ethanol, and the impurities on the surface of the polythiourea can be removed by washing the polythiourea with the methanol and/or the ethanol, so that purer polythiourea is obtained.

As an example, the third solvent may be methanol or ethanol alone, or may be a mixture of methanol and ethanol.

The ratio of the volume of the second solvent to the volume of the first solvent is more than or equal to 1.

The polythiourea dissolved in the first solvent can be precipitated by making the ratio of the volume of the second solvent to the volume of the first solvent be equal to or larger than 1.

Optionally, the ratio of the volume of the second solvent to the volume of the first solvent is greater than or equal to 10.

The number of times the solid is washed with the third solvent is 1 to 5 times.

Impurities doped in the polythiourea are removed or reduced in the purification step by means of sedimentation, filtration and washing, so that purer polythiourea is obtained.

The application also provides a polymer, which is prepared according to the preparation method of the polymer.

The polymer provided by the application has higher molecular weight, can be used for preparing solid electrolyte, forms tight combination through synergistic electrostatic action and hydrogen bonding action between thiourea groups and lithium ions, promotes dissolution of lithium salt in a polymer matrix, combines lithium ions, constructs an ion conduction channel, and assists movement of lithium ions in a mode of decoupling movement of polymer chain segments.

The application also provides a solid electrolyte comprising a lithium salt and the polymer described above.

The lithium salt comprises any one or more of lithium perchlorate, lithium bis (trifluoromethylsulfonyl) imide, lithium tetrafluoroborate and lithium bis (difluorosulfimide).

The lithium salt accounts for 1-80 wt% of the total mass of the solid electrolyte.

As an example, the lithium salt may account for 1wt%, 2wt%, 5wt%, 8wt%, 10w%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 75wt%, or 80wt% of the total mass of the solid electrolyte.

The solid electrolyte provided by the application has higher ionic conductivity and lithium ion transmission efficiency.

The solid electrolyte of the application can be prepared by adopting the existing preparation method, and the preparation method of the solid electrolyte is provided as follows:

respectively dissolving polythiourea and lithium salt according to a proportion, uniformly mixing to obtain a fourth mixture, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ion solid electrolyte PSE.

The application also provides a battery comprising the solid electrolyte.

The application also provides an electric device which comprises the battery.

A polymer, a method for preparing the same, and a solid electrolyte according to the present application are described in further detail below with reference to examples.

Example 1

The embodiment of the application provides a polymer and a preparation method thereof, and a solid electrolyte and a preparation method thereof, comprising the following steps:

S1, pretreatment

The reaction raw materials are subjected to drying and dehumidifying treatment, and the reaction kettle and the stirring device are subjected to drying treatment, wherein the drying temperature is 100 ℃.

S2, polymerization

Firstly, introducing nitrogen into a reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 2mmol of potassium tert-butoxide and 4mL of dimethyl sulfoxide into the reaction kettle, starting a stirring device, reacting for 2h at the temperature of 60 ℃ to prepare a second mixture, then adding 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and continuing to react for 12h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

And (3) settling the prepared third mixture in water, filtering to obtain a solid, washing the solid with methanol for 2 times, centrifugally collecting the precipitate, and drying the precipitate in a vacuum drying oven until the weight is constant to obtain a powdery product, wherein the powdery product is the polythiourea P1.

The structural formula of the prepared polythiourea P1 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P1 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO ₄ to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE1.

Example 2

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into a reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 2mmol of elemental sulfur, 2mmol of sodium hydroxide and 4mL of dimethyl sulfoxide into the reaction kettle, starting a stirring device, reacting for 2h at the temperature of 60 ℃ to prepare a second mixture, then adding 2mmol of potassium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and continuing to react for 12h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

And (3) settling the prepared third mixture in water, filtering to obtain a solid, washing the solid with methanol for 2 times, centrifugally collecting the precipitate, and drying the precipitate in a vacuum drying oven until the weight is constant to obtain a powdery product, wherein the powdery product is the polythiourea P2.

The structural formula of the prepared polythiourea P2 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P2 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO ₄ to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE2.

Example 3

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into a reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 3mmol of potassium tert-butoxide and 4mL of dimethyl sulfoxide into the reaction kettle, starting a stirring device, reacting for 2h at the temperature of 60 ℃ to prepare a second mixture, then adding 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and continuing to react for 12h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

And (3) settling the prepared third mixture in water, filtering to obtain a solid, washing the solid with methanol for 2 times, centrifugally collecting the precipitate, and drying the precipitate in a vacuum drying oven until the weight is constant to obtain a powdery product, wherein the powdery product is the polythiourea P3.

The structural formula of the prepared polythiourea P3 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P3 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO ₄ to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE3.

Example 4

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into a reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 3mmol of potassium tert-butoxide and 4mL of dimethyl sulfoxide into the reaction kettle, starting a stirring device, reacting for 0.1h at the temperature of 90 ℃ to prepare a second mixture, then adding 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and continuing to react for 1h at the temperature of 120 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

And (3) settling the prepared third mixture in water, filtering to obtain a solid, washing the solid with methanol for 2 times, centrifugally collecting the precipitate, and drying the precipitate in a vacuum drying oven until the weight is constant to obtain a powdery product, wherein the powdery product is the polythiourea P4.

The structural formula of the prepared polythiourea P4 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P4 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO ₄ to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE4.

Example 5

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into a reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 3mmol of potassium tert-butoxide and 4mL of dimethyl sulfoxide into the reaction kettle, starting a stirring device, reacting for 3h at the temperature of 25 ℃ to prepare a second mixture, then adding 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and continuing to react for 20h at the temperature of 25 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

And (3) settling the prepared third mixture in water, filtering to obtain a solid, washing the solid with methanol for 2 times, centrifugally collecting the precipitate, and drying the precipitate in a vacuum drying oven until the weight is constant to obtain a powdery product, wherein the powdery product is the polythiourea P5.

The structural formula of the prepared polythiourea P5 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P5 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO ₄ to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE5.

Comparative example 1

The application provides a polymer and a preparation method thereof, a solid electrolyte and a preparation method thereof, and the preparation method comprises the following steps:

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into the reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 2mmol of potassium tert-butoxide, 4mL of dimethyl sulfoxide, 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and reacting for 14h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

The structural formula of the prepared polythiourea P1 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P1 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO4 to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE6.

Comparative example 2

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into the reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 2mmol of elemental sulfur, 2mmol of sodium hydroxide, 4mL of dimethyl sulfoxide, 2mmol of potassium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and reacting for 14h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

The structural formula of the prepared polythiourea P1 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P1 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO4 to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE7.

Comparative example 3

S1, pretreatment

S2, polymerization

Firstly, introducing nitrogen into the reaction kettle for 1min to discharge air or oxygen in the reaction kettle, then, adding 1mmol of elemental sulfur, 3mmol of potassium tert-butoxide, 4mL of dimethyl sulfoxide, 2mmol of sodium hydroxide, 1mmol of diamine and 4mmol of anhydrous chloroform into the reaction kettle, and reacting for 14h at the temperature of 60 ℃ to prepare a third mixture.

Wherein the structural formula of the diamine is as follows:

s3, purifying

The structural formula of the prepared polythiourea P1 is as follows:

s4, preparing solid electrolyte

And respectively dissolving the prepared polythiourea P1 and lithium perchlorate, uniformly mixing to obtain a fourth mixture, enabling the doping ratio (r= [ Li ⁺ ]/[ C=S ]) of LiClO4 to be 4, pouring the fourth mixture into a polytetrafluoroethylene plate, and drying to obtain the super-ionic solid electrolyte PSE8.

Test example 1

The molecular weights and polydispersities of the polymers of examples 1 to 5 and comparative examples 1 to 3 were measured by GPC, respectively, and the results are shown in Table 1.

TABLE 1 molecular weight and polydispersity of the polymers of examples 1-5 and comparative examples 1-3

From the comparison of example 1 and comparative example 1, comparison of example 2 and comparative example 2, comparison of example 3 and comparative example 3 in Table 1, it is understood that the polymers produced by the process for producing a polymer of the present application have higher weight average molecular weight and better polydispersity. Wherein the polymer obtained in example 3 had a weight average molecular weight of 73000g/mol and a polydispersity of 1.44.

Test example 2

The solid electrolytes prepared in examples 1 to 3 were subjected to ion conductivity test: cutting the solid electrolyte membrane into regular slices, assembling the regular slices with stainless steel to form a pair of electrodes, adopting electrochemical alternating current impedance spectrum, measuring at different temperatures, wherein the frequency range is 1Hz to 100 kHz. The ion conductivity (σ) is calculated by the following formula: σ=d/(r×s), where σ is the ion conductivity (s·cm ^-1), d is the thickness of the electrolyte, R is the bulk resistance, and S represents the area in contact with the electrode, respectively, and the result is shown in fig. 1.

As can be seen from fig. 1, the solid electrolyte PSE3 prepared in example 3 has higher ionic conductivity than the solid electrolyte PSE2 prepared in example 2 and the solid electrolyte PSE1 prepared in example 1, and the solid electrolyte PSE1 prepared in example 1 has lower activation energy than the solid electrolyte PSE2 prepared in example 2 and the solid electrolyte PSE3 prepared in example 3.

Test example 3

The solid electrolytes prepared in examples 1 to 3 were subjected to a Li ⁺ migration number test: the solid electrolyte membrane was cut into regular sheets, assembled with lithium sheets into a Li/solid electrolyte/Li symmetric cell structure, and the Li ⁺ migration number was measured by combining electrochemical impedance spectroscopy and chronoamperometry (t _Li+).Li⁺ migration number was calculated by the following formula: t _Li+＝I_SS(ΔV-I₀ R₀)/I₀(ΔV-I_SSR_SS) using the Bruce-Vincent method, where Δv is the applied polarization voltage, I ₀ and R ₀ are the initial current and interface resistance before polarization, and I _ss and R _ss are the final state current and interface resistance after polarization, respectively, and the results are shown in table 3.

TABLE 2 Li ⁺ migration number of solid electrolytes prepared in examples 1 to 3

As can be seen from table 2, the solid state electrolyte PSE3 prepared in example 3 has a higher ion migration number than the solid state electrolyte PSE2 prepared in example 2 and the solid state electrolyte PSE1 prepared in example 1, which may be caused by pushing away benzene rings by the main chain.

The above description is only of specific embodiments of the application and is not intended to limit the application, but various modifications and variations can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of preparing a polymer, the method comprising: reacting a first mixture containing elemental sulfur, a first alkaline compound and a first solvent at a temperature of 25-90 ℃ for 0.1-3 hours to obtain a second mixture, mixing the second alkaline compound, diamine, anhydrous chloroform and the second mixture, and reacting at a temperature of 25-120 ℃ for 1-20 hours to obtain a third mixture;

Wherein the structural formula of the diamine is as follows:

2. The method of producing a polymer according to claim 1, wherein the method of producing a polymer satisfies at least one of the following conditions:

a. the molar ratio of the elemental sulfur to the diamine is 1-6:1;

b. the molar ratio of the first alkaline compound to the diamine is 1-6:1;

c. the molar ratio of the second alkaline compound to the diamine is 1-2:1;

d. The molar ratio of the anhydrous chloroform to the diamine is 1-6:1;

3. The method of producing a polymer according to claim 1, wherein the diamine comprises N is an integer of 1 to 9.

4. The method of producing a polymer according to claim 1, wherein the diamine comprisesN is an integer of 1 to 9.

5. The method for producing a polymer according to claim 1, wherein the first basic compound comprises any one or more of calcium hydroxide, potassium t-butoxide, sodium hydroxide, and potassium carbonate; and/or the number of the groups of groups,

6. The method for producing a polymer according to claim 2, wherein the first solvent comprises any one or more of pyridine, N-dimethylacetamide, t-butanol, 1, 4-dioxane, and dimethylsulfoxide.

7. The method for preparing a polymer according to claim 1, further comprising precipitating the third mixture in a second solvent, filtering to obtain a solid, washing the solid with the third solvent, and centrifuging to obtain the polythiourea.

8. The method of producing a polymer according to claim 7, wherein the second solvent comprises any one or more of water, cyclohexane, n-hexane, and methanol.

9. The method for producing a polymer according to claim 7, wherein a ratio of a volume of the second solvent to a volume of the first solvent is not less than 1.

10. The method of preparing a polymer according to claim 7, wherein the third solvent comprises methanol and/or ethanol.

11. A polymer, characterized in that it is produced according to the process for the preparation of a polymer according to any one of claims 1 to 10.

12. A solid state electrolyte comprising a lithium salt and the polymer of claim 11.

13. The solid state electrolyte of claim 12, wherein the lithium salt comprises 1wt% to 80wt% of the total mass of the solid state electrolyte.

14. The solid state electrolyte of claim 12 wherein the lithium salt comprises any one or more of lithium perchlorate, lithium bis (trifluoromethylsulfonyl) imide, lithium tetrafluoroborate, lithium bis-difluorosulfimide.

15. A battery comprising the solid electrolyte of any one of claims 12 to 14.

16. An electrical device comprising the battery of claim 15.