CN116014257A - A kind of preparation method of lithium-sulfur battery and lithium-sulfur battery - Google Patents
A kind of preparation method of lithium-sulfur battery and lithium-sulfur battery Download PDFInfo
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Abstract
The application provides a preparation method of a lithium sulfur battery and the lithium sulfur battery, which are applied to the technical field of batteries, wherein the method comprises the steps of obtaining a first solvent prepared from dioxolane, dimethoxyethane and dibenzyl diselenide; adding lithium salt into the first solvent to obtain battery electrolyte; after dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, adding dibenzyl diselenide into the dispersing agent to obtain anode slurry; and preparing the lithium sulfur battery by using the battery electrolyte and the positive plate obtained according to the positive slurry. According to the method, dibenzyl diselenide is added into the battery electrolyte and the positive plate, so that the aggregation of polysulfide formed by the positive sulfur in the lithium-sulfur battery due to circulation is prevented, and the battery capacity at low temperature is improved.
Description
Technical Field
The application relates to the technical field of batteries, in particular to a preparation method of a lithium-sulfur battery and the lithium-sulfur battery.
Background
Along with the increasing demands of communication base station construction in low-temperature areas such as high altitude, high latitude and the like, among a plurality of novel lithium batteries, the lithium sulfur battery becomes an ideal choice of a high-specific energy battery due to high theoretical capacity and high energy density. However, lithium sulfur batteries have a series of problems such as slow ion transport at low temperature, difficult desolvation of lithium ions, high interfacial charge transfer resistance, etc., which result in rapid decay of low-temperature performance, and practical performance far below its theoretical value.
In the existing preparation method of the lithium-sulfur battery, the desolvation energy barrier of the lithium ion is reduced at low temperature mainly through regulating and controlling the solvation structure of the lithium ion, so that the aim of improving the low-temperature performance of the lithium-sulfur battery is fulfilled, but the method ignores the characteristic that the lithium-sulfur battery is easy to dissolve polysulfide. As the temperature decreases, the electrolyte fluidity becomes worse, and the dissolution of polysulfide makes the electrode liquid more viscous, accelerating the aggregation of polysulfide, resulting in further decrease in battery capacity at low temperature.
Disclosure of Invention
The embodiment of the application provides a preparation method of a lithium sulfur battery and the battery, which are used for solving the problem of reduced battery capacity at low temperature in the existing preparation method of the lithium sulfur battery.
In order to solve the technical problems, the application is realized as follows:
in a first aspect, embodiments of the present application provide a method for preparing a lithium sulfur battery. The method comprises the following steps:
obtaining a first solvent prepared from dioxolane, dimethoxyethane and dibenzyl diselenide;
adding lithium salt into the first solvent to obtain battery electrolyte;
after dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, adding dibenzyl diselenide into the dispersing agent to obtain anode slurry;
and preparing the lithium sulfur battery by using the battery electrolyte and the positive plate obtained according to the positive slurry.
Optionally, the obtaining a first solvent prepared from dioxolane, dimethoxyethane, and dibenzyldiselenoether comprises:
obtaining a second solvent prepared from the dioxolane and the dimethoxyethane;
adding the dibenzyl diselenide into the second solvent to obtain a third solvent, wherein the concentration of the dibenzyl diselenide in the third solvent is 1-100 mmol/L;
after the third solvent is placed at a first temperature and stored for a first time period, the temperature is raised to a second temperature according to a first heating speed, the third solvent is stirred for a second time period at a first rotating speed, and the first solvent is obtained, wherein the value range of the first heating speed is 1-5 ℃ per hour, the first temperature is-20 ℃, the value range of the first time period is 5-10 hours, the second temperature is 25 ℃, the first rotating speed is 500 revolutions per minute, and the value range of the second time period is 12-24 hours.
Optionally, the obtaining a second solvent prepared from the dioxolane and the dimethoxyethane comprises:
mixing the dried dioxolane and the dried dimethoxyethane in an argon glove box according to a first volume ratio, and stirring the mixed dioxolane and dimethoxyethane for a third time period at a first rotating speed to obtain a second solvent, wherein the value range of the first volume ratio is 1:1-1:10, and the range of the third time period is 6-12 hours.
Optionally, before the dried dioxolane and dimethoxyethane are mixed in an argon glove box according to a first volume ratio and stirred at a first rotational speed for a third period of time to obtain the second solvent, the method further includes:
the dioxolane, the dimethoxyethane and the dibenzyl diselenide are respectively added into a glass bottle filled with a molecular sieve for drying, the drying time is a fourth time, the value range of the fourth time is 12-24 hours, the value range of the mass ratio of the dioxolane to the molecular sieve is 10:1-50:1, the value range of the mass ratio of the dimethoxyethane to the molecular sieve is 10:1-50:1, and the value range of the mass ratio of the dibenzyl diselenide to the molecular sieve is 10:1-50:1.
Optionally, adding lithium salt into the first solvent to obtain a battery electrolyte, including:
adding lithium salt into the first solvent, stirring the first solvent added with the lithium salt at a third temperature for a fifth time period to obtain a fourth solvent, wherein the value range of the concentration of the lithium salt in the fourth solvent is 0.2-1 mol/liter, the value range of the third temperature is 30-50 ℃, and the value range of the fifth time period is 12-24 hours;
and continuously adding the lithium salt into the fourth solvent, and stirring the fourth solvent added with the lithium salt at a third temperature for a fifth period of time to obtain battery electrolyte, wherein the value range of the concentration of the lithium salt in the battery electrolyte is 0.5-2 mol/L.
Optionally, after dispersing the conductive additive, the sulfur powder and the binder in the dispersing agent, dibenzyl diselenide ether is added to the dispersing agent to obtain a positive electrode slurry, which comprises:
dispersing a conductive additive, sulfur powder and a binder in a dispersing agent according to a first mass ratio to obtain first slurry, wherein the first mass ratio is 1:8:1, the value range of the volume of the dispersing agent is 1-10L, and the value range of the solid content in the dispersing agent is 0.1-1 g/L;
after the first slurry is stirred for a sixth time period according to a second rotating speed, adding dibenzyl diselenide ether with a first concentration for N times at a fourth temperature to obtain a second slurry, wherein the value range of N is 3-5, the value range of the interval time between every two times of adding the dibenzyl diselenide ether is 10-30 minutes, the value range of the volume of each time of adding the dibenzyl diselenide ether is 1-1000 milliliters, the value range of the first concentration is 10-2000 millimoles/liter, the value range of the second rotating speed is 50-300 revolutions/minute, the value range of the sixth time period is 3-6 hours, and the value range of the fourth temperature is 25-50 ℃;
and stirring the second slurry at a fifth temperature for a seventh time period to obtain positive electrode slurry, wherein the fifth temperature is 25 ℃, and the seventh time period is 12 hours.
Optionally, the conductive additive is conductive carbon-containing powder, the binder is one or more of polyvinylidene fluoride, sodium hydroxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polytetrafluoroethylene and polyvinyl alcohol, and the dispersing agent is one or more of dimethylformamide, methyl pyrrolidone, water and alcohol.
In a second aspect, embodiments of the present application also provide a lithium sulfur battery. The lithium sulfur battery is manufactured according to the manufacturing method of the lithium sulfur battery.
The preparation method of the lithium sulfur battery comprises the steps of obtaining a first solvent prepared from dioxolane, dimethoxyethane and dibenzyl diselenide; adding lithium salt into the first solvent to obtain battery electrolyte; after dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, adding dibenzyl diselenide into the dispersing agent to obtain anode slurry; and preparing the lithium sulfur battery by using the battery electrolyte and the positive plate obtained according to the positive slurry. According to the method, dibenzyl diselenide is added into the battery electrolyte and the positive plate, so that the aggregation of polysulfide formed by the positive sulfur in the lithium-sulfur battery due to circulation is prevented, and the battery capacity at low temperature is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments of the present application will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for preparing a lithium sulfur battery according to an embodiment of the present application;
fig. 2 is a charge-discharge graph of a lithium sulfur battery and a battery based on a control group according to an embodiment of the present application;
fig. 3 is a battery cycle diagram of a lithium sulfur battery and a control battery based on a first embodiment of the present application;
fig. 4 is a charge-discharge graph of a lithium sulfur battery provided according to embodiment two of the present application and a battery based on a control group;
fig. 5 is a battery cycle diagram of a lithium-sulfur battery provided based on embodiment three of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
The embodiment of the application provides a preparation method of a lithium-sulfur battery. Referring to fig. 1, fig. 1 is a flowchart of a method for preparing a lithium sulfur battery according to an embodiment of the present application, as shown in fig. 1, including the following steps:
and 104, preparing the lithium-sulfur battery through the battery electrolyte and the positive plate obtained according to the positive electrode slurry.
In order to solve the problem that the performance of the lithium-sulfur battery is rapidly attenuated in a low-temperature environment, the existing preparation method of the lithium-sulfur battery is more to reduce the desolvation energy barrier of the lithium-sulfur battery at a low temperature by regulating and controlling the solvation structure of lithium ions, so that the aim of improving the low-temperature performance of the lithium-sulfur battery is fulfilled. Although the method can improve the low-temperature performance of the battery to a certain extent, only desolvation of lithium ions is emphasized, the characteristic that the lithium-sulfur battery is easy to dissolve in polysulfide is ignored, as the temperature is reduced, the fluidity of the battery electrolyte is poor, the electrolyte is more viscous due to the dissolution of polysulfide, the aggregation of polysulfide is accelerated, and further the rapid attenuation of the battery capacity is caused.
In the preparation method of the lithium sulfur battery, a first solvent prepared from dioxolane, dimethoxyethane and dibenzyl diselenide is obtained, and then a lithium salt is added into the first solvent to obtain a battery electrolyte, wherein the lithium salt can be lithium triflate, lithium bis (trifluoromethanesulfonyl) imide and lithium bis (fluorosulfonyl) imide. After dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, adding dibenzyl diselenide into the dispersing agent to obtain positive electrode slurry, coating and drying the positive electrode slurry on an aluminum foil in a conventional manner, and finally obtaining the positive electrode plate modified by the dibenzyl diselenide. And assembling the obtained battery electrolyte and the positive plate in an argon glove box in a conventional manner to obtain the lithium-sulfur battery.
The method is carried out by introducing a special organic compound: dibenzyl diselenide is used as a redox regulating medium in electrochemical reaction to change electrostatic interaction of polysulfide in lithium-sulfur battery in conversion process so as to destroy Li + —S x 2- Thereby preventing the accumulation of polysulfides at low temperatures, which are derived from the positive sulfur of lithium sulfur batteries, which form polysulfides during battery cycling. Meanwhile, the dibenzyl diselenide can be added to graft at the tail end of polysulfide, so as to induce charge redistribution on the polysulfide surface, thereby changing the energy level of the lowest unoccupied orbit and the highest occupied orbit, reducing the electrochemical reaction energy barrier and further improving the unit capacity of the lithium-sulfur battery at low temperature. The grafting refers to chemically attaching one functional group to the surface of an object or to another functional group.
Optionally, the obtaining a first solvent prepared from dioxolane, dimethoxyethane, and dibenzyldiselenoether comprises:
obtaining a second solvent prepared from the dioxolane and the dimethoxyethane;
adding the dibenzyl diselenide into the second solvent to obtain a third solvent, wherein the concentration of the dibenzyl diselenide in the third solvent is 1-100 mmol/L;
after the third solvent is placed at a first temperature and stored for a first time period, the temperature is raised to a second temperature according to a first heating speed, the third solvent is stirred for a second time period at a first rotating speed, and the first solvent is obtained, wherein the value range of the first heating speed is 1-5 ℃ per hour, the first temperature is-20 ℃, the value range of the first time period is 5-10 hours, the second temperature is 25 ℃, the first rotating speed is 500 revolutions per minute, and the value range of the second time period is 12-24 hours.
In the preparation method of the lithium sulfur battery, a second solvent prepared from dioxolane and dimethoxyethane is obtained, dibenzyl diselenide is added into the second solvent to obtain a third solvent, wherein the concentration of the dibenzyl diselenide in the third solvent is in the range of 1-100 mmol/L. And then, after the third solvent is placed at the first temperature and stored for a first time period, the temperature is increased to a second temperature according to a first heating speed, and the third solvent is stirred for a second time period at a first rotating speed to obtain the first solvent, wherein the value range of the first heating speed is 1-5 ℃ per hour, the first temperature is-20 ℃, the value range of the first time period is 5-10 hours, the second temperature is 25 ℃, the first rotating speed is 500 revolutions per minute, and the value range of the second time period is 12-24 hours. The method is favorable for leading dibenzyl diselenide to carry out head-to-tail grafting with dioxolane and dimethoxyethane solvent molecules, and reduces the polymerization possibility after polysulfide dissolution. The grafting refers to chemically attaching one functional group to the surface of an object or to another functional group.
Illustratively, a second solvent prepared from dioxolane and dimethoxyethane is obtained, and dibenzyldiselenide ether is added to the second solvent to obtain a third solvent, wherein the concentration of dibenzyldiselenide ether in the third solvent may be 20 mmol/l. Subsequently, after the third solvent was kept at a temperature of-20 degrees centigrade for 5 hours, the temperature was raised to 25 degrees centigrade at a temperature rising rate of 2 degrees centigrade/hour, and the third solvent was stirred at a speed of 500 rotations/minute for 12 hours, to obtain the first solvent.
Optionally, the obtaining a second solvent prepared from the dioxolane and the dimethoxyethane comprises:
mixing the dried dioxolane and the dried dimethoxyethane in an argon glove box according to a first volume ratio, and stirring the mixed dioxolane and dimethoxyethane for a third time period at a first rotating speed to obtain a second solvent, wherein the value range of the first volume ratio is 1:1-1:10, and the range of the third time period is 6-12 hours.
In the preparation method of the lithium sulfur battery, the dried dioxolane and dimethoxyethane are mixed in an argon glove box according to a first volume ratio, and the mixed dioxolane and dimethoxyethane are stirred on a magnetic stirring table at a first rotating speed for a third time period to obtain a second solvent, wherein the value range of the first volume ratio is 1:1-1:10, and the range of the third time period is 6-12 hours. The method is beneficial to fully mixing the dioxolane and the dimethoxyethane.
Illustratively, the dried dioxolane and dimethoxyethane are prepared according to a ratio of 1:5 in an argon glove box, and stirring the mixed dioxolane and dimethoxyethane on a magnetic stirring table at 500 rpm for 6 hours to obtain a second solvent.
Optionally, before the dried dioxolane and dimethoxyethane are mixed in an argon glove box according to a first volume ratio and stirred at a first rotational speed for a third period of time to obtain the second solvent, the method further includes:
the dioxolane, the dimethoxyethane and the dibenzyl diselenide are respectively added into a glass bottle filled with a molecular sieve for drying, the drying time is a fourth time, the value range of the fourth time is 12-24 hours, the value range of the mass ratio of the dioxolane to the molecular sieve is 10:1-50:1, the value range of the mass ratio of the dimethoxyethane to the molecular sieve is 10:1-50:1, and the value range of the mass ratio of the dibenzyl diselenide to the molecular sieve is 10:1-50:1.
In the preparation method of the lithium sulfur battery, dioxolane, dimethoxyethane and dibenzyl diselenide are respectively added into a glass bottle filled with a molecular sieve for drying, the drying time is the fourth time, the value range of the fourth time is 12-24 hours, the value range of the mass ratio of the dioxolane to the molecular sieve is 10:1-50:1, the value range of the mass ratio of the dimethoxyethane to the molecular sieve is 10:1-50:1, and the value range of the mass ratio of the dibenzyl diselenide to the molecular sieve is 10:1-50:1. The method is used for drying the dioxolane, the dimethoxyethane and the dibenzyl diselenide, and is favorable for removing a small amount of water mixed in the compound.
Illustratively, dioxolane, dimethoxyethane and dibenzyl diselenide are added into a glass bottle filled with molecular sieves respectively for drying for 24 hours, wherein the mass ratio of the dioxolane to the molecular sieves is 20:1, the mass ratio of the dimethoxyethane to the molecular sieves is 20:1, and the mass ratio of the dibenzyl diselenide to the molecular sieves is 20:1.
Optionally, adding lithium salt into the first solvent to obtain a battery electrolyte, including:
adding lithium salt into the first solvent, stirring the first solvent added with the lithium salt at a third temperature for a fifth time period to obtain a fourth solvent, wherein the value range of the concentration of the lithium salt in the fourth solvent is 0.2-1 mol/liter, the value range of the third temperature is 30-50 ℃, and the value range of the fifth time period is 12-24 hours;
and continuously adding the lithium salt into the fourth solvent, and stirring the fourth solvent added with the lithium salt at a third temperature for a fifth period of time to obtain battery electrolyte, wherein the value range of the concentration of the lithium salt in the battery electrolyte is 0.5-2 mol/L.
In the preparation method of the lithium-sulfur battery, a lithium salt is added into a first solvent, the first solvent added with the lithium salt is stirred for a fifth time period at a third temperature to obtain a fourth solvent, wherein the value range of the concentration of the lithium salt in the fourth solvent is 0.2-1 mol/liter, the value range of the third temperature is 30-50 ℃, and the value range of the fifth time period is 12-24 hours. And then continuously adding lithium salt into the fourth solvent, and stirring the fourth solvent added with the lithium salt at a third temperature for a fifth period of time to obtain the battery electrolyte, wherein the value range of the concentration of the lithium salt in the battery electrolyte is 0.5-2 mol/L. The method is advantageous in that lithium salt is sufficiently dissolved in the battery electrolyte.
Illustratively, a lithium salt is added to the first solvent, and the first solvent to which the lithium salt is added is stirred at a temperature of 40 degrees celsius for 12 hours to obtain a fourth solvent, wherein the concentration of the lithium salt in the fourth solvent may be 0.2 mole/liter. Then, adding lithium salt into the fourth solvent continuously, and stirring the fourth solvent added with the lithium salt at the temperature of 40 ℃ continuously for 12 hours to obtain the battery electrolyte, wherein the concentration of the lithium salt in the battery electrolyte can be 0.5 mol/L.
Optionally, after dispersing the conductive additive, the sulfur powder and the binder in the dispersing agent, dibenzyl diselenide ether is added to the dispersing agent to obtain a positive electrode slurry, which comprises:
dispersing a conductive additive, sulfur powder and a binder in a dispersing agent according to a first mass ratio to obtain first slurry, wherein the first mass ratio is 1:8:1, the value range of the volume of the dispersing agent is 1-10L, and the value range of the solid content in the dispersing agent is 0.1-1 g/L;
after the first slurry is stirred for a sixth time period according to a second rotating speed, adding dibenzyl diselenide ether with a first concentration for N times at a fourth temperature to obtain a second slurry, wherein the value range of N is 3-5, the value range of the interval time between every two times of adding the dibenzyl diselenide ether is 10-30 minutes, the value range of the volume of each time of adding the dibenzyl diselenide ether is 1-1000 milliliters, the value range of the first concentration is 10-2000 millimoles/liter, the value range of the second rotating speed is 50-300 revolutions/minute, the value range of the sixth time period is 3-6 hours, and the value range of the fourth temperature is 25-50 ℃;
and stirring the second slurry at a fifth temperature for a seventh time period to obtain positive electrode slurry, wherein the fifth temperature is 25 ℃, and the seventh time period is 12 hours.
In the preparation method of the lithium-sulfur battery, the conductive additive, the sulfur powder and the binder are dispersed in the dispersing agent according to the first mass ratio to obtain the first slurry, wherein the first mass ratio is 1:8:1, the value range of the volume of the dispersing agent is 1-10L, and the value range of the solid content in the dispersing agent is 0.1-1 g/L. And (3) stirring the first slurry for a sixth time at a second rotating speed, and then adding dibenzyl diselenide ether with a first concentration for N times at a fourth temperature to obtain a second slurry, wherein the value range of N is 3-5, the value range of the interval time between every two times of adding dibenzyl diselenide ether is 10-30 minutes, the value range of the volume of each time of adding dibenzyl diselenide ether is 1-1000 milliliters, and the value range of the first concentration is 10-2000 millimoles/liter. The value range of the second rotating speed is 50-300 revolutions per minute, the value range of the sixth time period is 3-6 hours, and the value range of the fourth temperature is 25-50 ℃. And stirring the second slurry at a fifth temperature for a seventh time to obtain positive electrode slurry, wherein the fifth temperature is 25 ℃, the seventh time is 12 hours, and coating and drying the obtained positive electrode slurry on an aluminum foil in a conventional manner to finally obtain the positive electrode plate of the lithium-sulfur battery. The method is beneficial to improving the unit capacity of the lithium sulfur battery by introducing dibenzyl diselenide into the positive plate.
Illustratively, the conductive additive, sulfur powder, and binder are dispersed in a dispersant according to a first mass ratio to obtain a first slurry, wherein the first mass ratio is 1:8:1, the volume of the dispersant can be 5L, and the solid content in the dispersant can be 0.5 g/L. After the first slurry is stirred for 3 hours at 500 revolutions per minute, at the temperature of 40 ℃ for 10 minutes at intervals, 2 times of dibenzyl diselenide with the concentration of 10-2000 mmol/L are added to obtain second slurry, and the volume of each time of adding dibenzyl diselenide can be 1-1000 ml. The second slurry was then stirred at a temperature of 25 c for 12 hours to obtain a positive electrode slurry,
optionally, the conductive additive is conductive carbon-containing powder, the binder is one or more of polyvinylidene fluoride, sodium hydroxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polytetrafluoroethylene and polyvinyl alcohol, and the dispersing agent is one or more of dimethylformamide, methyl pyrrolidone, water and alcohol.
In the preparation method of the lithium sulfur battery, the conductive additive is conductive carbon-containing powder, wherein the carbon-containing powder can be one or more of carbon black, acetylene black, carbon nano tubes, carbon spheres, carbon fibers and the like, the binder is one or more of polyvinylidene fluoride, sodium hydroxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polytetrafluoroethylene and polyvinyl alcohol, and the dispersing agent is one or more of dimethylformamide, methyl pyrrolidone, water and alcohol. This facilitates the full contact of dibenzyl diselenide with sulfur, changes the electrostatic interaction of sulfur during conversion, damages Li + —S x 2- So that polysulfides do not agglomerate at low temperatures.
In a second aspect, embodiments of the present application also provide a lithium sulfur battery. The lithium sulfur battery is manufactured according to the manufacturing method of the lithium sulfur battery.
In order to further illustrate the beneficial effects obtained by the preparation method of the lithium sulfur battery in the embodiment of the present application, experiments were performed using the lithium sulfur battery prepared in the first embodiment of the present application and the second embodiment of the present application, and the battery electrolyte used in the comparative battery was a mixed solution of dimethyl carbonate and trifluoroethyl ether in which a concentration of 0.5 mol/l of lithium difluorosulfimide salt was dissolved in a volume ratio of 1:1.
In the present applicationIn the method for preparing a lithium-sulfur battery of example one, dioxolane, dimethoxyethane and dibenzyl diselenide are added separately to a battery equipped with
Drying in glass bottle of molecular sieve for 24 hr, wherein each liquid is mixed with +.>
The mass ratio of the molecular sieve is 20:1. The dried dioxolane and dimethoxyethane were mixed in a volume ratio of 1:5 in an argon glove box and then stirred on a magnetic stirring table at 500 rpm for 12 hours to give a second solvent. And then adding the dried dibenzyl diselenide into a second solvent to obtain a third solvent, controlling the concentration of the dibenzyl diselenide in the third solvent to be 20 mmol/L, immediately placing the third solvent in an environment of-20 ℃ for 5 hours, gradually raising the temperature to 25 ℃ according to the heating rate of 2 ℃ per hour, and stirring at the speed of 500 rpm for 12 hours to finally obtain the first solvent. Lithium bistrifluoromethylsulfonylimide was dissolved in the first solvent at a concentration of 0.2 mol/l, and the stirring temperature was increased to 40 degrees celsius and stirred for 12 hours. And then maintaining the stirring temperature unchanged, adding the lithium bistrifluoromethylsulfonyl imide for multiple times, and continuously stirring for 12 hours, so that the concentration of the lithium bistrifluoromethylsulfonyl imide in the obtained battery electrolyte is 0.5 mol/L.
Carbon black, sulfur powder and polyvinylidene fluoride are dispersed in 1 liter of dimethylformamide according to the mass ratio of 1:8:1, and a first slurry is obtained, wherein the solid content in the dimethylformamide is 0.5 g/liter. The first slurry was stirred at 50 rpm for 3 hours, then the stirring temperature was increased to 40 degrees celsius for 10 minutes each time 200 ml was added each time, and 2 dibenzyldiselenide ether was added at a concentration of 50 mmoles/liter to give a second slurry. After the addition, the temperature is restored to 25 ℃, and the mixture is stirred for 12 hours, so that the uniform anode slurry is finally obtained. And then, coating the anode slurry on an aluminum foil in a conventional manner, and drying to finally obtain the anode plate. And assembling the battery electrolyte and the positive plate in an argon glove box according to a conventional mode to obtain the lithium-sulfur battery.
Fig. 2 is a charge-discharge curve diagram of a lithium sulfur battery prepared in the first embodiment of the present application and a comparative battery used in a control group at a temperature of 0 ℃. As can be seen from the figure, in the lithium sulfur battery prepared in example 1 of the present application, by introducing dibenzyl diselenide, the electrochemical reaction barrier of the lithium sulfur battery at low temperature is reduced, so as to improve the electrochemical potential, and the discharge platform in example 1 of the present application is obviously higher than that of the control group, and the higher reaction potential can ensure that the overall capacity of the battery is not excessively attenuated after the temperature is continuously reduced.
Fig. 3 is a cycle chart of a comparative battery used in the first and control groups of the present application at a temperature of 0 ℃. In example 1 of the present application, li which is easily aggregated at a low temperature is destroyed as compared with the control group + —S x 2- Chains, which reduce the viscosity of the electrolyte, can maintain longer cycling stability.
In the method for preparing the lithium sulfur battery in the second embodiment of the present application, dioxolane, dimethoxyethane and dibenzyl diselenide are added respectively to the battery
Drying in glass bottle of molecular sieve for 12 hr, wherein each liquid is mixed with +.>
The mass ratio of the molecular sieve is 10:1. The dried dioxolane and dimethoxyethane were mixed in an argon glove box at a volume ratio of 1:2 and then stirred on a magnetic stirring table at 500 rpm for 12 hours to give a second solvent. Then adding the dried dibenzyl diselenide into a second solvent to obtain a third solvent, controlling the concentration of the dibenzyl diselenide in the third solvent to be 50 millimoles/liter, then immediately placing the third solvent in an environment of-20 ℃ for 10 hours, and gradually raising the temperature to 25 ℃ according to the temperature raising speed of 5 ℃ per hourThe mixture was stirred at 500 rpm for 12 hours to finally obtain a first solvent. Lithium bis (fluorosulfonyl) imide was dissolved in the first solvent at a concentration of 0.5 mol/l, and the stirring temperature was increased to 45 degrees celsius and stirred for 12 hours. And then maintaining the stirring temperature unchanged, adding the lithium bis (fluorosulfonyl) imide for multiple times, and continuously stirring for 12 hours, so that the concentration of the lithium bis (trifluoromethylsulfonyl) imide in the obtained battery electrolyte is 1 mol/liter.
Dispersing carbon nano tubes, sulfur powder and sodium hydroxymethyl cellulose in 5 liters of water according to a mass ratio of 1:8:1 to obtain a first slurry, wherein the solid content of the water is 0.5 g/liter. The first slurry was stirred at 100 rpm for 3 hours, then the stirring temperature was increased to 30 degrees celsius, and 1 200 milliliters of dibenzyldiselenide ether at a concentration of 50 mmoles/liter was added to obtain a second slurry. After the addition, the temperature is restored to 25 ℃, and the mixture is stirred for 12 hours, so that the uniform anode slurry is finally obtained. And then, coating the anode slurry on an aluminum foil in a conventional manner, and drying to finally obtain the anode plate. And assembling the battery electrolyte and the positive plate in an argon glove box according to a conventional mode to obtain the lithium-sulfur battery.
Fig. 4 is a charge-discharge curve diagram of a lithium sulfur battery according to the second embodiment of the present application and a comparative battery of a control group under an extremely low temperature condition of-30 ℃. It can be seen that, for the control group, lithium ion transmission was blocked, and the lithium sulfur battery hardly released capacity and coulombic efficiency were also low due to the influence of low temperature. In example 2 of the present application, the capacity of the lithium-sulfur battery of example 2 was significantly increased to 395 milliamp hours per gram, which is more than 2 times that of the control group, thanks to the reduction of the electrochemical reaction barrier.
In the preparation method of the lithium sulfur battery in the third embodiment of the application, dioxolane, dimethoxyethane and dibenzyl diselenide are respectively added and filled
Drying in glass bottle of molecular sieve for 24 hr, wherein each liquid is mixed with +.>
The mass ratio of the molecular sieve is 50:1. The dried dioxolane and dimethoxyethane were mixed in an argon glove box at a volume ratio of 1:5 and then stirred on a magnetic stirring table at 500 rpm for 6 hours to give a second solvent. And then adding the dried dibenzyl diselenide into a second solvent to obtain a third solvent, controlling the concentration of the dibenzyl diselenide in the third solvent to be 80 millimoles/liter, immediately placing the third solvent in an environment of-20 ℃ for 10 hours, gradually raising the temperature to 25 ℃ according to the temperature raising speed of 1 ℃ per hour, and stirring at the speed of 500 revolutions per minute for 24 hours to finally obtain the first solvent. Lithium triflate was dissolved in the first solvent at a concentration of 1 mol/liter, and the stirring temperature was increased to 50 degrees celsius and stirred for 24 hours. And then maintaining the stirring temperature unchanged, adding the lithium triflate for a plurality of times, and continuing stirring for 24 hours, so that the concentration of the lithium triflate in the battery electrolyte is finally 2 mol/L.
Acetylene black, sulfur powder and polyvinylidene fluoride are dispersed in 5 liters of methyl pyrrolidone according to the mass ratio of 1:8:1 to obtain a first slurry, wherein the solid content of the methyl pyrrolidone is 1 g/liter. The first slurry was stirred at 300 rpm for 6 hours, then the stirring temperature was increased to 40 degrees celsius at 15 minute intervals of 500 ml each time, and 5 times of 50 mmol/l dibenzyl diselenide ether was added to obtain a second slurry. After the addition, the temperature is restored to 25 ℃, and the mixture is stirred for 12 hours, so that the uniform anode slurry is finally obtained. And then, coating the anode slurry on an aluminum foil in a conventional manner, and drying to finally obtain the anode plate. And assembling the battery electrolyte and the positive plate in an argon glove box according to a conventional mode to obtain the lithium-sulfur battery.
Fig. 5 is a cycle curve of a lithium sulfur battery prepared in example three of the present application. It can be seen that the introduction of dibenzyl diselenide effectively improves the initial capacity and the cycle performance of the lithium sulfur battery. Even in an environment of-30 degrees celsius, example 3 of the present application maintained an initial capacity of up to 334 milliamp-hours per gram, and after 150 cycles, the capacity was maintained at 390 milliamp-hours per gram, with good cycle performance and stability.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk), including several instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method described in the embodiments of the present application.
The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those of ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are also within the protection of the present application.
Claims (8)
1. A method for preparing a lithium sulfur battery, the method comprising:
obtaining a first solvent prepared from dioxolane, dimethoxyethane and dibenzyl diselenide;
adding lithium salt into the first solvent to obtain battery electrolyte;
after dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, adding dibenzyl diselenide into the dispersing agent to obtain anode slurry;
and preparing the lithium sulfur battery by using the battery electrolyte and the positive plate obtained according to the positive slurry.
2. The method of manufacturing a lithium sulfur battery according to claim 1, wherein the obtaining a first solvent prepared from dioxolane, dimethoxyethane, and dibenzyl diselenide comprises:
obtaining a second solvent prepared from the dioxolane and the dimethoxyethane;
adding the dibenzyl diselenide into the second solvent to obtain a third solvent, wherein the concentration of the dibenzyl diselenide in the third solvent is 1-100 mmol/L;
after the third solvent is placed at a first temperature and stored for a first time period, the temperature is raised to a second temperature according to a first heating speed, the third solvent is stirred for a second time period at a first rotating speed, and the first solvent is obtained, wherein the value range of the first heating speed is 1-5 ℃ per hour, the first temperature is-20 ℃, the value range of the first time period is 5-10 hours, the second temperature is 25 ℃, the first rotating speed is 500 revolutions per minute, and the value range of the second time period is 12-24 hours.
3. The method of producing a lithium sulfur battery according to claim 2, wherein the obtaining a second solvent produced from the dioxolane and the dimethoxyethane comprises:
mixing the dried dioxolane and the dried dimethoxyethane in an argon glove box according to a first volume ratio, and stirring the mixed dioxolane and dimethoxyethane for a third time period at a first rotating speed to obtain a second solvent, wherein the value range of the first volume ratio is 1:1-1:10, and the range of the third time period is 6-12 hours.
4. The method for preparing a lithium sulfur battery according to claim 3, wherein the dried dioxolane and dimethoxyethane are mixed in an argon glove box according to a first volume ratio and stirred at a first rotational speed for a third period of time to obtain the second solvent, and before the method further comprises:
the dioxolane, the dimethoxyethane and the dibenzyl diselenide are respectively added into a glass bottle filled with a molecular sieve for drying, the drying time is a fourth time, the value range of the fourth time is 12-24 hours, the value range of the mass ratio of the dioxolane to the molecular sieve is 10:1-50:1, the value range of the mass ratio of the dimethoxyethane to the molecular sieve is 10:1-50:1, and the value range of the mass ratio of the dibenzyl diselenide to the molecular sieve is 10:1-50:1.
5. The method for preparing a lithium-sulfur battery according to claim 1, wherein the step of adding a lithium salt to the first solvent to obtain a battery electrolyte comprises:
adding lithium salt into the first solvent, stirring the first solvent added with the lithium salt at a third temperature for a fifth time period to obtain a fourth solvent, wherein the value range of the concentration of the lithium salt in the fourth solvent is 0.2-1 mol/liter, the value range of the third temperature is 30-50 ℃, and the value range of the fifth time period is 12-24 hours;
and continuously adding the lithium salt into the fourth solvent, and stirring the fourth solvent added with the lithium salt at a third temperature for a fifth period of time to obtain battery electrolyte, wherein the value range of the concentration of the lithium salt in the battery electrolyte is 0.5-2 mol/L.
6. The method for producing a lithium-sulfur battery according to claim 1, wherein after dispersing a conductive additive, sulfur powder and a binder in a dispersing agent, dibenzyldiselenide is added to the dispersing agent to obtain a positive electrode slurry, comprising:
dispersing a conductive additive, sulfur powder and a binder in a dispersing agent according to a first mass ratio to obtain first slurry, wherein the first mass ratio is 1:8:1, the value range of the volume of the dispersing agent is 1-10L, and the value range of the solid content in the dispersing agent is 0.1-1 g/L;
after the first slurry is stirred for a sixth time period according to a second rotating speed, adding dibenzyl diselenide ether with a first concentration for N times at a fourth temperature to obtain a second slurry, wherein the value range of N is 3-5, the value range of the interval time between every two times of adding the dibenzyl diselenide ether is 10-30 minutes, the value range of the volume of each time of adding the dibenzyl diselenide ether is 1-1000 milliliters, the value range of the first concentration is 10-2000 millimoles/liter, the value range of the second rotating speed is 50-300 revolutions/minute, the value range of the sixth time period is 3-6 hours, and the value range of the fourth temperature is 25-50 ℃;
and stirring the second slurry at a fifth temperature for a seventh time period to obtain positive electrode slurry, wherein the fifth temperature is 25 ℃, and the seventh time period is 12 hours.
7. The method of claim 6, wherein the conductive additive is a conductive carbonaceous powder, the binder is a mixture of one or more of polyvinylidene fluoride, sodium hydroxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polytetrafluoroethylene, and polyvinyl alcohol, and the dispersant is a mixture of one or more of dimethylformamide, methylpyrrolidone, water, and alcohol.
8. A lithium-sulfur battery, characterized in that it is manufactured according to the lithium-sulfur battery manufacturing method according to any one of claims 1-7.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008047402A (en) * | 2006-08-14 | 2008-02-28 | Sony Corp | Nonaqueous electrolyte secondary battery |
| CN113206255A (en) * | 2021-05-06 | 2021-08-03 | 中国铁塔股份有限公司四川省分公司 | High-performance lithium-sulfur battery composite positive electrode material and preparation method thereof |
| CN113540567A (en) * | 2021-07-07 | 2021-10-22 | 清华大学 | A kind of lithium-sulfur battery electrolyte and preparation method thereof |
| CN113594545A (en) * | 2021-07-27 | 2021-11-02 | 宁德新能源科技有限公司 | Lithium-sulfur battery and electronic device comprising same |
-
2023
- 2023-01-16 CN CN202310072402.1A patent/CN116014257B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008047402A (en) * | 2006-08-14 | 2008-02-28 | Sony Corp | Nonaqueous electrolyte secondary battery |
| CN113206255A (en) * | 2021-05-06 | 2021-08-03 | 中国铁塔股份有限公司四川省分公司 | High-performance lithium-sulfur battery composite positive electrode material and preparation method thereof |
| CN113540567A (en) * | 2021-07-07 | 2021-10-22 | 清华大学 | A kind of lithium-sulfur battery electrolyte and preparation method thereof |
| CN113594545A (en) * | 2021-07-27 | 2021-11-02 | 宁德新能源科技有限公司 | Lithium-sulfur battery and electronic device comprising same |
Non-Patent Citations (1)
| Title |
|---|
| 肖元化;苏当成;王雪兆;王振兴;方少明;吴诗德;周立明;李峰;: "二维层状金属硒化物在电化学能源领域中的应用", 科学通报, no. 27, 30 September 2017 (2017-09-30) * |
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