CN114678579B - Lithium-sulfur battery electrolyte containing phenylselenol additive and lithium-sulfur battery - Google Patents

Lithium-sulfur battery electrolyte containing phenylselenol additive and lithium-sulfur battery Download PDF

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CN114678579B
CN114678579B CN202210233538.1A CN202210233538A CN114678579B CN 114678579 B CN114678579 B CN 114678579B CN 202210233538 A CN202210233538 A CN 202210233538A CN 114678579 B CN114678579 B CN 114678579B
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sulfur
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CN114678579A (en
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郭玮
孙俊鹏
郑思晨
付永柱
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Zhengzhou University
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    • 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
    • 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
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
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Abstract

The invention discloses a lithium-sulfur battery electrolyte containing a phenylselenophene (PhSeH) additive and a lithium-sulfur battery. The electrolyte comprises an ether solvent, lithium salt and an additive, wherein the additive is phenylselenophene. According to the electrolyte of the lithium sulfur battery, the organic micromolecular selenol phenylselenophene is used as an additive, S atoms are fixed through Se-S bonds, an intermediate product PhSeSSePH is generated in the charging and discharging process, the intermediate product PhSeSSePH returns to a sulfur simple substance state in the later stage of the charging process, the original redox path of the battery is changed, the battery process is completely reversible, the high capacity characteristic of the lithium sulfur battery is fully realized, and the cycling stability of the lithium sulfur battery is greatly improved.

Description

Lithium-sulfur battery electrolyte containing phenylselenol additive and lithium-sulfur battery
Technical Field
The invention belongs to the technical field of lithium-sulfur battery electrolyte, and particularly relates to a lithium-sulfur battery electrolyte containing a phenylselenol additive and a lithium-sulfur battery.
Background
With the rapid development of portable electronic devices, society is increasingly concerned with the development of lithium batteries. 372mAh g of lithium ion battery -1 The theoretical specific capacity of (c) has failed to meet the needs of the public. Meanwhile, the lithium sulfur battery has 2600Wh kg due to the lithium sulfur battery -1 Is favored by researchers due to the energy density and abundant sulfur resource reserves in the crust. During discharge, S 8 Accept 8 electrons and 8 Li + Corresponding to 1675mAh g -1 Is a theoretical specific capacity of (c). However, lithium sulfur batteries also face the following challenges: (1) severe shuttle effect: the high-order lithium polysulfide has higher solubility in an ether electrolyte system used in a lithium sulfur battery, so that the lithium polysulfide is led to migrate in the battery, which is led to diffuse to a negative electrode and react with a lithium sheet, and the problems of loss of active substance sulfur, corrosion of the lithium sheet, reduction of coulombic efficiency and even safety are caused. (2) Due to S 8 And the charge and discharge products have lower ionic conductivity and electronic conductivity, the reaction kinetics of the battery is slower,the active material utilization rate is low. Thus, to enhance the electrochemical performance of the battery, current work is focused mainly on inhibiting the shuttling effect of the sulfide, enhancing the conductivity of the positive electrode material, and replacing the traditional electrolyte components. The organic sulfur compound is a novel lithium sulfur battery anode material which can be used for replacing elemental sulfur. If the Se element participates in the composition of the electrode material, the cell will exhibit a lower voltage hysteresis due to its higher ionic conductivity.
The addition of electrolyte additives may form an isolation layer near the positive electrode by changing the kind of active material, catalyze disproportionation reaction of lithium polysulfide, react with lithium polysulfide, or change the composition of the SEI film to help form a denser SEI film, but at the same time inevitably reduces the energy density of the battery, sometimes with respect to the flammability, toxicity, viscosity, ionic conductivity, etc. of the electrolyte, may pose serious challenges. Therefore, it is urgent to find an electrolyte additive that enhances the electrochemical performance of a battery while suppressing the formation of lithium polysulfide.
Disclosure of Invention
The invention aims to provide a lithium-sulfur battery electrolyte containing a phenylselenol additive and a lithium-sulfur battery. The additive phenylselenophene realizes the fixation of S atoms through Se-S bonds, generates an intermediate product PhSeSSePH in the charging and discharging processes, returns to a sulfur simple substance state in the later stage of the charging process, changes the original redox path of the battery, fully inverts the battery process, fully realizes the high capacity characteristic of the lithium-sulfur battery, and greatly improves the cycling stability of the lithium-sulfur battery.
In order to solve the technical problems, the invention provides the following technical scheme:
the lithium sulfur battery electrolyte containing the phenylselenophene additive comprises an ether solvent, lithium salt and the additive, wherein the additive is phenylselenophene.
According to the scheme, the concentration of the phenylselenol in the electrolyte is 0.05-1.0 mol/L.
According to the scheme, the ether solvent is a mixed solution of DME (ethylene glycol dimethyl ether) and DOL (1, 3-dioxolane), wherein the volume ratio of the DME to the DOL solvent is (0.8-1.2): 1.
According to the scheme, the lithium salt is LiTFSI (lithium bis (trifluoromethylsulfonyl imide)) and LiNO 3 A mixture, wherein the concentration of LiTFSI is 1.0-1.5 mol/L, liNO 3 The concentration of (C) is 0.15-0.25 mol/L.
A lithium sulfur battery is provided, which comprises a positive electrode material, a negative electrode material, a diaphragm and the lithium sulfur battery electrolyte containing the phenylselenophene additive.
According to the scheme, the anode material is multi-wall carbon nano tube paper loaded with elemental sulfur.
Preferably, the sulfur loading is 0.88-1.15 mg cm -2 The diameter of the carbon nanotube paper is 11-13 mm.
According to the scheme, the preparation method of the positive electrode material comprises the following steps: a certain amount of elemental sulfur is dissolved in a proper amount of carbon disulfide, after the elemental sulfur is completely dissolved, a proper amount of solution is dripped on the multi-wall carbon nano tube paper, and then the multi-wall carbon nano tube paper is dried in a blast oven at 60-65 ℃ for 12-13 hours to completely volatilize the solvent.
According to the scheme, the anode material is a lithium metal sheet.
According to the scheme, the diaphragm is Celgard 2400.
According to the scheme, the electrolyte containing the phenylselenophene additive is dripped on two sides of the diaphragm, so that the electrolyte is fully contacted with the anode and the cathode, and the lithium-sulfur battery is assembled.
The application of the phenylselenol as an additive in the electrolyte of the lithium-sulfur battery is provided.
The application of the lithium sulfur battery electrolyte containing the phenylselenol additive in the lithium sulfur battery is provided, wherein:
when the lithium-sulfur battery is a button battery, the concentration of the phenylselenol in the electrolyte is 0.5-1.0 mol/L;
when the lithium-sulfur battery is a soft-package battery, the concentration of the phenylselenol in the electrolyte is 0.05-0.30 mol/L.
When the lithium sulfur battery electrolyte containing the phenylselenol additive is used for a lithium sulfur battery, the charge-discharge oxidation-reduction reaction path of the battery is changed, long-chain polysulfide generation and shuttling in the charge-discharge process are avoided, and positive electrode active substances are reducedLoss, the battery performance is improved; wherein: during the discharge process, the phenylselenophene reacts with elemental sulfur to generate an intermediate product PhSeSSePh, and finally, phenylselenomethiol (PhSeLi) and lithium sulfide (Li) 2 S), avoiding the generation of long chain polysulfides; during charging, the phenylselenium free radical is combined with the sulfur free radical to generate an intermediate product PhSeSSePH, but because the Se-S bond energy is lower, the Se-S bond is broken at high voltage, and the PhSeSSePH generated during charging is decomposed and returns to S again 8 Simple substance state, so that the battery process is more reversible. In conclusion, after the phenylselenol is introduced into a lithium-sulfur battery system as an electrolyte additive, the reaction path of the traditional lithium-sulfur battery is changed, the generation of lithium polysulfide is reduced, and the shuttle effect is inhibited, so that the utilization rate of active substances is improved, and the electrochemical performance of the battery is improved.
The beneficial effects of the invention are as follows:
the lithium sulfur battery electrolyte provided by the invention takes the organic micromolecular phenylselenophene as an electrolyte additive, the phenylselenophene realizes the fixation of S atoms through Se-S bonds, phSeSSePH is generated in the charging and discharging process, and the phenylselenophene returns to S in the later stage of the charging process 8 The state avoids the generation and shuttling of long-chain polysulfide in the charge and discharge process, improves the utilization rate of active substances, and the battery is more reversible; meanwhile, the overall overpotential of the battery is reduced due to the higher ion conductivity of Se element; when the electrolyte is used for a lithium sulfur battery, the electrochemical performance is excellent, and the electrolyte has 1436mAh g at 0.5C multiplying power -1 The maximum discharge specific capacity of (2) is 1300mAh g after 200 circles -1 The reversible specific capacity of the lithium sulfur battery is 91.86%, the high capacity characteristic of the lithium sulfur battery is fully realized, the cycling stability of the lithium sulfur battery is greatly improved, and the potential of commercial application of the lithium sulfur battery is improved.
Drawings
FIG. 1 is a graph showing the long cycle performance at 1C rate of a lithium sulfur CR2032 coin cell containing 0.50mol/L phenylselenol additive in example 1 of the invention.
FIG. 2 is a voltage-capacity curve at 1C rate for a lithium sulfur CR2032 coin cell containing 0.50mol/L phenylselenol additive in example 1 of the invention.
FIG. 3 is a graph showing the long cycle performance at 1C rate of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive in example 2 of the invention.
FIG. 4 is a voltage-capacity curve at 1C rate for a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive in example 2 of the invention.
FIG. 5 is a graph showing the long cycle performance at 1C rate of a lithium sulfur CR2032 coin cell containing 1.0mol/L phenylselenol additive in example 3 of the invention.
FIG. 6 is a voltage-capacity curve at 1C rate for a lithium sulfur CR2032 coin cell containing 1.0mol/L phenylselenophene additive in example 3 of the present invention.
FIG. 7 is a voltage-capacity curve at 0.5C rate for a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive and a matrix electrolyte corresponding to a lithium sulfur CR2032 coin cell of example 4 of the invention.
FIG. 8 is a graph showing the long cycle performance at 0.5C rate of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive and a corresponding lithium sulfur CR2032 coin cell of the matrix electrolyte in example 4 of the invention.
FIG. 9 is a graph showing the rate performance of lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenophene additive in example 4 of the present invention.
FIG. 10 is a graph showing the cycle performance of a lithium sulfur soft pack battery containing 0.10mol/L phenylselenophene additive in example 5 of the present invention.
FIG. 11 is a mass spectrum of phenylselenol (PhSeH) produced by substituting proton hydrogen for lithium in phenylselenol lithium (PhSeLi) which is a discharge product of lithium sulfur CR2032 button cell containing 0.70mol/L phenylselenol additive in example 4 of the present invention.
FIG. 12 is a mass spectrum of diphenyl diselenide (PhSeSePh) which is a charged product of lithium sulfur CR2032 button cell comprising 0.70mol/L phenylselenophene additive in example 4 of the present invention.
FIG. 13 is a mass spectrum of a charged product PhSeSSePh (DPDSeS) of a lithium sulfur CR2032 button battery containing 0.70mol/L of phenylselenophene additive in example 4 of the present invention.
FIG. 14 is a UV-Vis comparison chart of the positive electrode of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive in example 4 of the invention and a lithium sulfur CR2032 coin cell corresponding to a matrix electrolyte when discharged to 2.1V.
FIG. 15 is an in situ Raman spectrum of the first-cycle discharge process of a lithium sulfur CR2032 button cell containing 0.70mol/L phenylselenol additive in example 4 of the invention.
FIG. 16 is an in situ Raman spectrum of a lithium sulfur CR2032 coin cell battery of example 4 of the invention containing 0.70mol/L phenylselenophene additive.
FIG. 17 is an XPS chart (S2 p) of the positive electrode after charging of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive in example 4 of the invention.
FIG. 18 is an XPS (Se 3 d) of the positive electrode of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenophene additive in example 4 of the present invention after charging.
FIG. 19 is an XPS (Se 3 d) of the positive electrode of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive in example 4 of the invention after discharge.
FIG. 20 is a FT-IR spectrum of phenylselenophene and a reaction mixture of elemental sulfur and phenylselenophene in example 4 of the present invention.
FIG. 21 is an ex situ Raman spectrum of elemental sulfur and a phenylselenophene starting material and a reaction mixture of the two in example 4 of the present invention.
FIG. 22 is an SEM image of the sulfur positive electrode of a lithium sulfur CR2032 button cell containing 0.70mol/L phenylselenophene additive of example 4 of the present invention after charging.
FIG. 23 is an SEM image of the sulfur positive electrode of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenol additive of example 4 of the invention after discharge.
FIG. 24 is a TEM image of a sulfur positive electrode after charging of a lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenophene additive in example 4 of the present invention.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings, so that those skilled in the art can better understand the technical scheme of the present invention.
Example 1
Provides a lithium sulfur battery electrolyte containing a phenylselenophene additive, which comprises an ether solvent, a lithium salt andan additive; wherein the ether solvent is a mixed solution of DOL and DME in a volume ratio of 1:1, and the lithium salts LiTFSI and LiNO 3 LiTFSI concentration is 1mol/L, liNO 3 The concentration is 0.15mol/L, the additive is phenylselenophene (PhSeH), and the concentration is 0.50mol/L.
The lithium-sulfur battery electrolyte containing the phenylselenophene additive obtained in the embodiment is assembled with a carbon nano tube anode, a diaphragm and a lithium metal cathode loaded with elemental sulfur to form the CR2032 button battery.
In the carbon nano tube anode loaded with the sulfur simple substance, the sulfur loading amount is 1mg, and the diameter of the carbon nano tube paper is 11mm. The sulfur solid powder is dissolved in a carbon disulfide solvent and then is dripped on carbon nanotube paper, and the carbon nanotube paper is dried in a blast oven at 60-65 ℃ for 12-13 hours to volatilize the solvent, thus obtaining the carbon nanotube carbon fiber composite material.
The diaphragm was Celgard-2400 with a diameter of 19mm.
The lithium metal anode had a thickness of 450 μm and a diameter of 15.6mm.
Electrochemical tests were performed on the lithium sulfur CR2032 coin cell described above containing 0.50mol/L phenylselenophene electrolyte.
FIG. 1 shows a long-cycle performance curve of a lithium-sulfur CR2032 button cell containing 0.50mol/L phenylselenol with a reversible specific capacity of 1100mAh g obtained in this example at a 1C rate -1 The coulomb efficiency is as high as 99%, and the capacity and the coulomb efficiency are hardly attenuated after 100 circles.
FIG. 2 shows the voltage-capacity curve of the lithium sulfur CR2032 button cell containing 0.50mol/L phenylselenol obtained in this example at a 1C rate, and three more obvious discharge platforms can be seen, with less cell overpotential.
Example 2
Providing a lithium sulfur battery electrolyte containing a phenylselenophene additive, wherein the lithium sulfur battery electrolyte comprises an ether solvent, lithium salt and an additive; wherein the ether solvent is a mixed solution of DOL and DME in a volume ratio of 1:1, and the lithium salts LiTFSI and LiNO 3 LiTFSI concentration is 1mol/L, liNO 3 The concentration is 0.15mol/L, the additive is phenylselenophene (PhSeH), and the concentration is 0.70mol/L.
The lithium-sulfur battery electrolyte containing the phenylselenophene additive obtained in the embodiment is assembled with a carbon nano tube anode, a diaphragm and a lithium metal cathode loaded with elemental sulfur to form the CR2032 button battery.
In the carbon nano tube anode loaded with the sulfur simple substance, the sulfur loading amount is 1mg, and the diameter of the carbon nano tube paper is 11mm. The sulfur solid powder is dissolved in a carbon disulfide solvent and then is dripped on carbon nanotube paper, and the carbon nanotube paper is dried in a blast oven at 60-65 ℃ for 12-13 hours to volatilize the solvent, thus obtaining the carbon nanotube carbon fiber composite material.
The diaphragm was Celgard-2400 with a diameter of 19mm.
The lithium metal anode had a thickness of 450 μm and a diameter of 15.6mm.
Electrochemical tests were performed on the lithium sulfur CR2032 coin cell described above containing 0.70mol/L phenylselenophene electrolyte.
FIG. 3 is a graph showing the long cycle performance curve of a 0.70mol/L phenylselenophene-containing lithium sulfur CR2032 button cell with a maximum specific discharge capacity of 1248mAh g at a 1C rate -1 。
FIG. 4 shows the voltage-capacity curve of the lithium sulfur CR2032 button cell containing 0.70mol/L phenylselenol obtained in this example at a 1C rate, and three more obvious discharge platforms can be seen, with less cell overpotential.
Example 3
Providing a lithium sulfur battery electrolyte containing a phenylselenophene additive, wherein the lithium sulfur battery electrolyte comprises an ether solvent, lithium salt and an additive; wherein the ether solvent is a mixed solution of DOL and DME in a volume ratio of 1:1, and the lithium salts LiTFSI and LiNO 3 LiTFSI concentration is 1mol/L, liNO 3 The concentration is 0.15mol/L, the additive is phenylselenophene (PhSeH), and the concentration is 1.0mol/L respectively.
The lithium-sulfur battery electrolyte containing the phenylselenophene additive obtained in the embodiment is assembled with a carbon nano tube anode, a diaphragm and a lithium metal cathode loaded with elemental sulfur to form the CR2032 button battery.
In the carbon nano tube anode loaded with the sulfur simple substance, the sulfur loading amount is 1mg, and the diameter of the carbon nano tube paper is 11mm. The sulfur solid powder is dissolved in a carbon disulfide solvent and then is dripped on carbon nanotube paper, and the carbon nanotube paper is dried in a blast oven at 60-65 ℃ for 12-13 hours to volatilize the solvent, thus obtaining the carbon nanotube carbon fiber composite material.
The diaphragm was Celgard-2400 with a diameter of 19mm.
The lithium metal anode had a thickness of 450 μm and a diameter of 15.6mm.
Electrochemical tests were performed on the lithium sulfur CR2032 coin cell described above containing 1.0mol/L phenylselenophene electrolyte.
FIG. 5 shows the long cycle performance curve of a lithium sulfur CR2032 button cell containing 1.0mol/L phenylselenol obtained in this example at a 1C rate, with a reversible specific capacity of 1100mAh g after 40 cycles -1 The coulomb efficiency is as high as 99%, and the capacity and the coulomb efficiency are hardly attenuated after 100 circles.
FIG. 6 shows the voltage-capacity curve of a lithium sulfur CR2032 button cell containing 1.0mol/L phenylselenol obtained in this example at a 1C rate, and three more obvious discharge platforms can be seen, with less cell overpotential.
Example 4
Providing a lithium sulfur battery electrolyte containing a phenylselenophene additive, wherein the lithium sulfur battery electrolyte comprises an ether solvent, lithium salt and an additive; wherein the ether solvent is a mixed solution of DOL and DME in a volume ratio of 1:1, and the lithium salts LiTFSI and LiNO 3 LiTFSI concentration is 1mol/L, liNO 3 The concentration is 0.15mol/L, the additive is phenylselenophene (PhSeH), and the concentration is 0.70mol/L.
Preparing a matrix lithium sulfur electrolyte, wherein the matrix lithium sulfur electrolyte contains 1mol/L LiTFSI and 0.15mol/L LiNO 3 DOL and DME (DOL to DME volume ratio of 1:1). The matrix lithium sulfur electrolyte was used as a control for setting up the control group.
The lithium sulfur battery electrolyte or matrix lithium sulfur electrolyte containing the phenylselenol additive obtained in the embodiment is assembled with a carbon nano tube anode, a diaphragm and a lithium metal cathode loaded with elemental sulfur to form a CR2032 button battery, so as to obtain an experimental group and a control group respectively.
In the carbon nano tube anode loaded with the sulfur simple substance, the sulfur loading amount is 1mg, and the diameter of the carbon nano tube paper is 11mm. The sulfur solid powder is dissolved in a carbon disulfide solvent and then is dripped on carbon nanotube paper, and the carbon nanotube paper is dried in a blast oven at 60-65 ℃ for 12-13 hours to volatilize the solvent, thus obtaining the carbon nanotube carbon fiber composite material.
The diaphragm was Celgard-2400 with a diameter of 19mm.
The lithium metal anode had a thickness of 450 μm and a diameter of 15.6mm.
Electrochemical tests were performed on the above-described lithium sulfur CR2032 coin cell containing 0.70mol/L phenylselenophene electrolyte (experimental group) and lithium sulfur CR2032 coin cell containing matrix electrolyte (control group), and the positive electrode after cycling thereof was characterized by liquid phase-mass spectrometry (LC-MS), ultraviolet-visible spectrum characterization (UV-Vis), in-situ and ex-situ Raman spectroscopy (Raman), X-ray photoelectric spectroscopy (XPS), fourier transform infrared absorption spectroscopy (FT-IR), scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM).
Fig. 7 is a voltage-capacity curve of lithium sulfur CR2032 coin cells of the experimental group and the control group obtained in this example at a 0.5C magnification, and the data marked in the graph are voltage hysteresis of the cells of the experimental group and the control group, respectively. It can be seen that the experimental group was only 0.22V with respect to the voltage hysteresis of 0.28V for the control group, which was significantly reduced.
Fig. 8 is a graph showing the long cycle performance of lithium sulfur CR2032 coin cells of the experimental group and the control group obtained in this example at a 0.5C magnification. The maximum discharge specific capacity of the lithium sulfur battery of the experimental group is 1436mAh g -1 While the control group is only 800mAh g -1 . After 200 circles, the experimental group can still keep 1300mAh g -1 The specific capacity of the water-based paint is 91.86%, and compared with a control group, the circulating performance of the water-based paint is obviously improved.
Fig. 9 is a graph showing the rate performance of lithium-sulfur CR2032 coin cells of the experimental group obtained in this example. At 0.1, 0.2, 0.5, 1.2, 1, 0.5, 0.2 and 0.1C rates, the specific discharge capacities of the batteries were 1450,1380,1300,1180,1050,1170,1250,1330,1360mAh g, respectively -1 . After this, the cell remained at about 1100mAh g after recycling for 70 cycles at 0.5C rate -1 The specific capacity of the battery indicates that the rate performance of the battery is good.
Fig. 11 is a mass spectrum of the positive electrode of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example in a discharge state, and a discharge product of phenylselenyllithium (PhSeLi) was detected. Since lithium ions are replaced by hydrogen protons during the detection process, phenylselenophene (PhSeH) is actually detected, and its mass-to-charge ratio is 157.9600.
FIG. 12 is a mass spectrum of the positive electrode of the lithium-sulfur CR2032 coin cell of the experimental group obtained in this example in a charged state, and a charged product C was detected 12 H 10 Se 2 The mass to charge ratio was 313.9184.
FIG. 13 is a mass spectrum of the positive electrode of the lithium-sulfur CR2032 coin cell of the experimental group obtained in this example in a charged state, and a charged product C was detected 12 H 10 Se 2 S, the mass-to-charge ratio is 345.8857. This suggests that the association of phenylselenophene with elemental sulfur during charging produces PhSeSSePh (DPDSeS) containing Se-S bonds, which alters the original redox pathway of lithium sulfur batteries, thereby reducing polysulfide formation and shuttling.
Fig. 14 is a UV-vis test performed on the positive electrode when the lithium sulfur CR2032 coin cell of the experimental group and the lithium sulfur CR2032 coin cell of the control group obtained in this example were discharged to 2.1V. The graph shows that polysulfide S is detected when the lithium sulfur cells of the control group discharge to 2.1V 4 2- /S 6 2- Characteristic peaks at 275nm indicate polysulfide production during discharge. When the lithium sulfur battery containing the additive in the experimental group is discharged to 2.1V, the characteristic peak of polysulfide is not detected, and the additive is proved to change the charging and discharging process of sulfur simple substance, so that the generation of polysulfide is limited.
FIG. 15 is an in-situ Raman spectrum of the first-round discharge process of the lithium-sulfur CR2032 button cell of the experimental group obtained in this example, firstly, elemental sulfur (S 8 ) At 150cm -1 ，215cm -1 And 470cm -1 Disappearance of characteristic peak at site, explaining S 8 The molecules react. 340cm -1 The strong peak at the position is attributed to Se-S bond, which indicates that the phenylselenophene and S are generated before the discharge process is started 8 And (3) a chemical combination reaction and DPDSES generation. The peak intensity was continuously reduced during the discharge until almost complete disappearance at the end of the first discharge (2.05V).
Fig. 16 is an in situ Raman spectrum of the lithium sulfur CR2032 coin cell first cycle charge of the experimental set obtained in this example. Se-S bond 340cm -1 The characteristic peak at the position gradually increases with the progress of charging, and the charging is performedThe strongest signal was found to be at 2.35V, confirming that Se-S bonds are generated during charging, consistent with DPDSES generation detected by LC-MS during charging. When charged to 2.41V, the characteristic peak of Se-S bond gradually weakens, indicating cleavage of Se-S bond. When charged to 3.00V, the characteristic peak of Se-S bond completely disappears, and sulfur simple substance (S 8 ) At 150cm -1 ，215cm -1 And 470cm -1 The appearance of characteristic peaks at the positions indicates S 8 And regenerating the molecules. In-situ Raman analysis shows that sulfur free radicals are captured by phenylselenium free radicals to form Se-S bonds in the charging process, so that polysulfide formation and shuttling are avoided; in the later stage of the charging process, se-S bonds are broken to generate elemental sulfur, and the elemental sulfur is kept consistent with the state at the beginning of discharging, so that the battery is highly reversible in the charging and discharging process.
Fig. 17 is an XPS chart (S2 p) of the positive electrode after charging of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example. Detection of charging product S 8 Non-polar S-S bonds (162.2/160.8 eV).
Fig. 18 is an XPS graph (Se 3 d) of the positive electrode after charging of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example. Se-Se bonds (165.08/158.59 eV) of the charged product PhSeSePh were detected.
Fig. 19 is an XPS graph (Se 3 d) of the positive electrode after discharge of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example. Se-Li bonds (54.73/55.77 eV) of the final discharge product phenylselenyllithium (PhSeLi) were detected.
FIG. 20 is a FT-IR spectrum of a reaction mixture of phenylselenophene and elemental sulfur. 2300cm -1 The disappearance of Se-H signals shows that the phenylselenophene reacts with elemental sulfur, and the content is reduced.
FIG. 21 is a Raman spectrum of elemental sulfur and a phenylselenophene starting material, as well as a reaction mixture of the two. Elemental sulfur (S) 8 ) Is at 150cm -1 ，215cm -1 And 470cm -1 . Raman shift elimination and 360cm position of elemental sulfur in the reaction mixture -1 The occurrence of raman shift at Se-S demonstrates the formation of molecules containing Se-S bonds. This result is consistent with the generation of PhSeSSePh (DPDSeS) during the actual battery cycle detected by the LC-MS.
Fig. 22 is an SEM image of the positive electrode of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example after charging. The charged products are uniformly distributed in the carbon nanotube network and are closely adhered around the carbon nanotubes, and the three-dimensional globular deposition form is presented.
Fig. 23 is an SEM image of the positive electrode of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example after discharge. It can be seen that the morphology of the charged product is similar, and the charged product is uniformly and dispersedly deposited on the carbon nano-tubes in a small sphere shape.
Fig. 24 is a TEM image of the positive electrode of the lithium sulfur CR2032 coin cell of the experimental group obtained in this example after charging, which is consistent with the appearance obtained by SEM image, and is spherical three-dimensional deposition and uniform distribution.
Example 5
Providing a lithium sulfur battery electrolyte containing a phenylselenophene additive, wherein the lithium sulfur battery electrolyte comprises an ether solvent, lithium salt and an additive; wherein the ether solvent is a mixed solution of DOL and DME in a volume ratio of 1:1, and the lithium salts LiTFSI and LiNO 3 LiTFSI concentration is 1mol/L, liNO 3 The concentration is 0.15mol/L, the additive is phenylselenophene (PhSeH), and the concentration is 0.10mol/L.
Here, it should be noted that, when the concentration of the phenylselenol in the soft pack battery is too high, formation of the lithium negative electrode SEI layer of the soft pack battery is unfavorable to some extent, and therefore, a proper reduction of the phenylselenol concentration is favorable to improvement of the long cycle performance of the soft pack battery relative to the button cell. In the soft-package battery, the applicable concentration of the phenylselenol is 0.05-0.30 mol/L. In practical applications, the optimum concentration of phenylselenophene should be selected based on battery performance.
And injecting the electrolyte into the lithium sulfur soft package battery to assemble the lithium sulfur soft package battery. The pouch cell was purchased from the new materials science co.ltd, henna microliter (Hunan Vincere New Material Technology co., LTD) and had a total sulfur loading of 1.2g and was used for testing only in the examples.
FIG. 10 is a graph showing the cycle performance of a lithium sulfur pouch cell containing 0.10mol/L phenylselenophene additive, obtained in this example, at 50mA current. The maximum discharge capacity of the battery is 1398mAh.
It is apparent that the above examples are only examples given for clarity of illustration and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. And thus obvious variations or modifications to the disclosure are within the scope of the invention.

Claims (10)

1. The lithium sulfur battery electrolyte containing the phenylselenophene additive is characterized by comprising an ether solvent, lithium salt and the additive, wherein the additive is phenylselenophene.
2. The electrolyte of claim 1, wherein the concentration of the phenylselenol in the electrolyte is 0.05 to 1.0mol/L.
3. The electrolyte of claim 1, wherein the ether solvent is a mixture of DME and DOL, and wherein the volume ratio of DME to DOL solvent is (0.8-1.2): 1.
4. The electrolyte of claim 1 wherein the lithium salts are LiTFSI and LiNO 3 A mixture, wherein the concentration of LiTFSI is 1.0-1.5 mol/L, liNO 3 The concentration of (C) is 0.15-0.25 mol/L.
5. A lithium sulfur battery comprising a positive electrode material, a negative electrode material, a separator, and the phenylselenol additive-containing lithium sulfur battery electrolyte of any one of claims 1-4.
6. The lithium sulfur battery of claim 5 wherein the positive electrode material is a multiwall carbon nanotube paper loaded with elemental sulfur.
7. The lithium sulfur battery of claim 6 wherein the sulfur loading is 0.88 to 1.15mg cm -2 。
8. The lithium sulfur battery of claim 5 wherein the negative electrode material is a lithium metal sheet; the membrane is Celgard 2400.
9. The application of the phenylselenol as an additive in lithium-sulfur battery electrolyte.
10. Use of the phenylselenophene additive-containing lithium sulfur battery electrolyte as claimed in any one of claims 1 to 4 in lithium sulfur batteries, wherein:
when the lithium-sulfur battery is a button battery, the concentration of the phenylselenol in the electrolyte is 0.5-1.0 mol/L;
when the lithium-sulfur battery is a soft-package battery, the concentration of the phenylselenol in the electrolyte is 0.05-0.30 mol/L.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107785603A (en) * 2017-09-12 2018-03-09 深圳启辰新能源科技有限公司 Lithium-sulfur cell electrolyte and preparation method thereof and the battery using the electrolyte
WO2018164642A1 (en) * 2017-03-07 2018-09-13 Agency For Science, Technology And Research A method of preparing metal nanoclusters
CN108963195A (en) * 2017-05-18 2018-12-07 中国科学院宁波材料技术与工程研究所 A kind of lithium selenium cell anode composite material and preparation method thereof
CN109650348A (en) * 2018-12-18 2019-04-19 深圳先进技术研究院 Transition metal chalcogenide nanoscale twins material and preparation method thereof, cell negative electrode material, secondary cell and its application
CN111613784A (en) * 2020-05-22 2020-09-01 郑州大学 Organic-inorganic composite lithium-selenium battery positive electrode material and preparation method and application thereof
CN112018356A (en) * 2020-08-17 2020-12-01 五邑大学 Flaky potassium ion negative electrode material
CN112018357A (en) * 2020-08-17 2020-12-01 五邑大学 Electrode composite material
CN113394460A (en) * 2021-06-24 2021-09-14 郑州大学 Lithium-sulfur battery electrolyte containing benzenetrithiol additive and lithium-sulfur battery

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190341623A1 (en) * 2018-05-01 2019-11-07 National Technology & Engineering Solutions Of Sandia, Llc Carbon coated nano-materials and metal oxide electrodes, and methods of making the same
CN109830661B (en) * 2019-01-16 2022-01-04 五邑大学 Selenium-doped MXene composite nano material and preparation method and application thereof

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018164642A1 (en) * 2017-03-07 2018-09-13 Agency For Science, Technology And Research A method of preparing metal nanoclusters
CN108963195A (en) * 2017-05-18 2018-12-07 中国科学院宁波材料技术与工程研究所 A kind of lithium selenium cell anode composite material and preparation method thereof
CN107785603A (en) * 2017-09-12 2018-03-09 深圳启辰新能源科技有限公司 Lithium-sulfur cell electrolyte and preparation method thereof and the battery using the electrolyte
CN109650348A (en) * 2018-12-18 2019-04-19 深圳先进技术研究院 Transition metal chalcogenide nanoscale twins material and preparation method thereof, cell negative electrode material, secondary cell and its application
CN111613784A (en) * 2020-05-22 2020-09-01 郑州大学 Organic-inorganic composite lithium-selenium battery positive electrode material and preparation method and application thereof
CN112018356A (en) * 2020-08-17 2020-12-01 五邑大学 Flaky potassium ion negative electrode material
CN112018357A (en) * 2020-08-17 2020-12-01 五邑大学 Electrode composite material
CN113394460A (en) * 2021-06-24 2021-09-14 郑州大学 Lithium-sulfur battery electrolyte containing benzenetrithiol additive and lithium-sulfur battery

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Selenonium Polyelectrolyte Synthesis through Post-Polymerization Modifications of poly(Glycidyl Methacrylate) Scaffolds;Taejun Eom and Anzar Khan;《polymers》;第12卷;第1-9页 *
载体化的苯硫酚、苯硒酚阴离子的制备及其反应;张万轩等;《离子交换与吸附》;第14卷(第01期);第36-40页 *

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