CN114464891B - Ultralow-density electrolyte and lithium sulfur battery - Google Patents
Ultralow-density electrolyte and lithium sulfur battery Download PDFInfo
- Publication number
- CN114464891B CN114464891B CN202011236792.4A CN202011236792A CN114464891B CN 114464891 B CN114464891 B CN 114464891B CN 202011236792 A CN202011236792 A CN 202011236792A CN 114464891 B CN114464891 B CN 114464891B
- Authority
- CN
- China
- Prior art keywords
- lithium
- electrolyte
- battery
- density
- ultra
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—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
- H01M10/0569—Liquid materials characterised by the solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
- H01M2300/0028—Organic electrolyte characterised by the solvent
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention relates to an ultralow-density electrolyte and a lithium sulfur battery. The density of the ultralow-density electrolyte is less than 0.9g/ml; the ultralow-density electrolyte comprises lithium salt and a nonaqueous organic solvent; wherein, the single molecular structure of the nonaqueous organic solvent contains at most two nucleophilic sites and/or at most three fluorine atoms, the length of the main carbon chain is not more than 7 carbon atoms, and at most two alkane branched structures are contained; the dielectric constant of the nonaqueous organic solvent is less than 7, so that the dissociation or dissolution of the polysulfide compound in the nonaqueous organic solvent is inhibited under the limit of the polar functional group; in the ultralow-density electrolyte, the total concentration of lithium salt ranges from 0.01M to 1.2M. Under the condition of the same electrolyte volume, the weight proportion of the electrolyte in the lithium-sulfur full battery can be greatly reduced by adopting the electrolyte, so that the overall energy density of the lithium-sulfur primary battery and the lithium-sulfur secondary battery can be effectively improved, and the cycle stability of the lithium-sulfur battery can be effectively improved.
Description
Technical Field
The invention relates to the technical field of materials, in particular to an ultralow-density electrolyte and a lithium-sulfur battery.
Background
Along with the development demands of 3C products and new energy electric vehicles for long endurance, the energy storage market puts forward higher demands on the energy density of lithium ion batteries. However, due to the limitations of conventional "de-intercalation" type positive and negative electrode materials, the energy density of lithium ion batteries has approached its limit of energy density (< 300 Wh/Kg), and thus the development of secondary batteries having higher energy densities has been a trend. The lithium-sulfur battery has 2600Wh/Kg theoretical energy density, has the advantages of wide material source, low price, no pollution and the like, and is considered as a new secondary battery system with the most development prospect in the future.
Although the lithium sulfur battery has higher theoretical energy density, the actual energy density can only reach 300-400Wh/Kg due to the excessively high weight ratio of inactive substances (> 70 wt%) in the actual application process, namely, the actual energy density can only reach about 15% of the theoretical energy density. Wherein, the weight proportion of the electrolyte in the lithium sulfur full battery is the highest (> 50 wt%) so that reducing the weight proportion of the electrolyte in the lithium sulfur full battery is an important way for improving the energy density of the lithium sulfur battery. The most straightforward way is to reduce the amount of electrolyte used in lithium sulfur batteries. However, reducing the amount of electrolyte used in lithium sulfur batteries is currently a significant challenge due to the excessive porosity (> 70 vol%) of the sulfur positive electrode and the special "solid-liquid" conversion process during charge and discharge.
At the same electrolyte usage/sulfur mass (E/S) ratio, the density of different electrolytes can lead to a large difference in total electrolyte weight, which can lead to a large change in lithium sulfur full cell energy density. Therefore, the invention solves the problems in the prior art from the aspect of reducing the electrolyte density, and effectively reduces the mass proportion of the electrolyte in the full battery by reducing the electrolyte density, thereby realizing the purpose of improving the actual energy density of the lithium-sulfur battery. Therefore, the development of the electrolyte with the ultra-low density has great significance for improving the energy density of the lithium-sulfur battery.
Disclosure of Invention
The embodiment of the invention provides an ultralow-density electrolyte and a lithium sulfur battery, which can greatly reduce the weight proportion of the electrolyte in the lithium sulfur full battery under the condition of the same E/S ratio, thereby effectively improving the overall energy density of the lithium sulfur battery and the cycle stability of the lithium sulfur battery.
In a first aspect, embodiments of the present invention provide an ultra-low density electrolyte having a density of less than 0.9g/ml; the ultra-low density electrolyte comprises lithium salt and a nonaqueous organic solvent;
wherein, the single molecular structure of the nonaqueous organic solvent contains at most two nucleophilic sites and/or at most three fluorine atoms, the length of the main carbon chain is not more than 7 carbon atoms, and at most two alkane branched structures are contained;
the dielectric constant of the non-aqueous organic solvent is less than 7, so that the dissociation or dissolution of the polysulfide in the non-aqueous organic solvent is inhibited under the limit of the polar functional group;
in the ultralow-density electrolyte, the total concentration range of lithium salt is between 0.01M and 1.2M.
Preferably, the nonaqueous organic solvent at least comprises an ether or alkane with the density of less than 0.85g/ml and a corresponding fluorinated solvent, and the ether or alkane with the density of less than 0.85g/ml and the corresponding fluorinated solvent account for 20-90% of the total volume of the nonaqueous organic solvent.
Preferably, in the ultralow-density electrolyte, the ratio of the density of the ultralow-density electrolyte to the density of the solvent is less than or equal to 1.1 when the concentration of the lithium salt is less than 1.0M, and the ultralow-density electrolyte has an ion conductivity of > 1 mS/cm.
Preferably, the lithium salt includes: lithium nitrate (LiNO) 3 ) Lithium iodide (LiI), lithium bromide (LiBr), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI), lithium 1,2, 3-hexafluoropropane-1, 3-disulfonate imide (LiHFDF), lithium perchlorate (LiClO) 4 ) One or more of lithium bis (fluorosulfonyl) imide (LiFSI), lithium trifluoroacetate (LiFSA), lithium bis (fluorosulfonyl) trifluoromethylsulfonyl imide (LiFTFSI), lithium (tf) trifluoromethane sulfonate (LiTf), lithium bis (pentafluoroethane) sulfonyl imide (LiBETI).
Further preferably, the lithium salt specifically includes: liNO 3 And LiTFSI.
Preferably, the nonaqueous organic solvent includes: methyl Propyl Ether (MPE), and ethylene glycol dimethyl ether (DME), acetonitrile (AN), 1, 3-Dioxolane (DOL), dimethoxymethane (MMA), tetrahydrofuran (THF), methyl tetrahydrofuran (mehf), diethyl ether (EE), methyl tert-butyl ether (MTBE), methyl n-butyl ether (MBE), propyl ether (DE), isopropyl ether (IPE), n-Pentane (PE), n-Hexane (HE), n-Heptane (HEP), n-Octane (OCT), fluorinated solvents corresponding to ether solvents in the above solvents, and isomers corresponding to alkane solvents in the above solvents or mixtures of one or more fluorinated systems.
Preferably, the viscosity of the ultra-light electrolyte is between 0.45 mpa.s and 1.20 mpa.s at 25 ℃.
In a second aspect, an embodiment of the present invention provides a lithium sulfur battery according to the first aspect, where the lithium sulfur battery includes the ultralow-density electrolyte according to the first aspect; the lithium sulfur battery includes a lithium sulfur primary battery or a lithium sulfur secondary battery.
Preferably, the positive electrode material of the lithium-sulfur battery comprises Mo 6 S 8 With TiS 2 Is a composite material of one or two of S, wherein the Mo 6 S 8 With TiS 2 Is used for inhibiting the shuttle effect in the lithium-sulfur battery and simultaneously playing an electrocatalytic role.
Preferably, the positive electrode material of the lithium-sulfur battery further comprises a conductive carbon nanotube and graphene composite as a conductive additive.
The ultralow-density electrolyte provided by the embodiment of the invention scientifically and reasonably defines lithium salt and nonaqueous organic solvent which meet the conditions, so that the electrolyte formed by the lithium salt and the nonaqueous organic solvent can greatly reduce the weight proportion of the electrolyte in the lithium-sulfur full battery under the same E/S ratio condition, thereby effectively improving the overall energy density of the lithium-sulfur battery and effectively improving the cycle stability of the lithium-sulfur battery.
Drawings
The technical scheme of the embodiment of the invention is further described in detail through the drawings and the embodiments.
FIG. 1 is a schematic representation of the density of different solvents at 25 ℃;
FIG. 2 is a schematic representation of an ultra-light solvent having a density in the range of (0.6-0.8) g/mL;
FIG. 3 is a comparison of electrochemical performance test results of inventive example 1 and comparative example 1.
Detailed Description
The invention is further illustrated by the drawings and the specific examples, which are to be understood as being for the purpose of more detailed description only and are not to be construed as limiting the invention in any way, i.e. not intended to limit the scope of the invention.
In order to better understand the intention of the invention, firstly, the idea and idea of the technical scheme of the invention are analyzed and described.
In the research, we find that the high weight fraction ratio of the electrolyte in the lithium-sulfur full cell is the main reason for the large gap between the actual energy density and the theoretical value. So far, it has been challenging for lithium sulfur batteries to further reduce the E/S ratio to E/S < 3uL/mg due to the high electrode porosity of lithium sulfur batteries and the limitations of metallic lithium negative electrodes on electrolyte consumption. In addition to the E/S ratio, we believe that electrolyte density is also another key parameter in determining electrolyte weight in a full cell, but was ignored in previous studies. The density of the conventional lithium sulfur electrolyte is even higher than that of the lithium ion battery electrolyte. Therefore, if the electrolyte density can be reduced to effectively reduce the mass proportion of the electrolyte in the full battery, the aim of improving the actual energy density of the lithium-sulfur battery can be achieved.
According to the analysis, the invention provides an ultralow-density electrolyte comprising lithium salt and a nonaqueous organic solvent;
in the practice of the present invention, we evaluated electrolyte densities of different salts as a function of their concentrations, while also considering the chemical compatibility of lithium salts with polysulfides, as well as ionic conductivity, to determine lithium salts that can be used in the ultra low density electrolytes of the present invention.
In addition to lithium salts, the density of the solvent used has a large relationship with the molecular weight, polarity, structure and functional groups of the solvent. FIG. 1 shows a graph of the densities of the solvents used for the different electrolytes at 25℃divided into four regions according to the densities. From bottom to top, it can be seen that the gas/liquid/solid phase diagrams correspond to densities, respectively<0.6g/mL, a density of 0.6-1.8g/mL and a density>1.8 g/mL. At a density of less than 0.6 g.mL -1 Within the scope of (2), solvent molecules are generally gaseous at room temperature, are generally nonpolar or have small molecular dimensions. Cooling or pressurizing the polar gas may form a liquefied gas electrolyte, but may severely degrade the dynamic performance of the lithium sulfur battery. In the liquid zone, the catalyst can be further divided into a conventional zone (0.85-1.2 g/mL) and an ultra-light zone<0.85 g/mL). The results show that the density of common electrolyte solvents (including ether, ester and fluorinated solvents) is above 0.85g/ml, which means that ultra low concentration and even salt free electrolyte densities cannot be below 0.85 g/ml. Therefore, we are closely concerned withUltra-light solvents are injected, typically having a density of less than 0.8g/mL in the liquid phase. FIG. 2 shows a density of (0.6-0.8) g.multidot.mL -1 Some candidate solvents for ultra-light solvents in the range. In general, ultra-light solvents have low polarity and low dielectric constant resulting in lower salt dissolution capacity. Thus, some solvents such as n-pentane (0.63 g.multidot.mL) -1 ) Hexane (0.66 g.mL) -1 ) N-heptane (0.68 g.mL) -1 ) And n-octane (0.70 g.mL) -1 ) Is excluded because there are no strong nucleophilic sites in the low dielectric constant molecules, resulting in unsatisfactory salt solubility. Thus, we have focused on monoethers having one Lewis basic oxygen atom, which not only have lower densities than ethers having multiple oxygen atoms, but also have a moderate dielectric constant that favors salt solubility. In addition, these ethers have high reduction resistance and show high compatibility with lithium metal, compared with other kinds of high polar ether solvents. Considering that the polarity of ether solvents decreases with increasing number of branches and C/O ratio, we are more concerned with linear ethers of low C/O ratio (i.e. C/o=4, 5, 6).
After researching the matching behavior of lithium salt and solvent, we also choose Methyl Propyl Ether (MPE) to be added into the solvent as cosolvent, and the unique molecular structure thereof ensures that the electrolyte has the characteristics of low viscosity, medium polarity, inertness to lithium metal and low polysulfide solubility, thus ensuring that the electrolyte has low density and high ionic conductivity.
Based on the above technical analysis demonstration and implementation, in the ultralow density electrolyte provided by the embodiment, the single molecular structure of the nonaqueous organic solvent contains at most two nucleophilic sites and/or at most two fluorine atoms, the length of the main carbon chain is not more than 7 carbon atoms, and at most two alkane branched structures are contained; the dielectric constant of the nonaqueous organic solvent is less than 7, so that the polysulfide compound is limited by the polar functional group and is not dissociated or dissolved in the nonaqueous organic solvent;
further, the nonaqueous organic solvent at least comprises an ether or alkane with the density of less than 0.85g/ml and a corresponding fluorinated solvent, and the ether or alkane with the density of less than 0.85g/ml and the corresponding fluorinated solvent account for 20-90% of the total volume content of the nonaqueous organic solvent.
The density of the ultralow-density electrolyte provided by the invention is less than 0.9g/ml, and the total concentration range of lithium salt in the ultralow-density electrolyte is between 0.01M and 1.2M. Wherein the ratio of the density of the ultralow electrolyte to the density of the solvent is less than or equal to 1.1 at a concentration of lithium salt < 1.0M, and has an ionic conductivity of > 1 mS/cm.
Based on the above constraints on the lithium salt and the nonaqueous organic solvent, the lithium salt constituting the ultralow-density electrolyte of the invention may specifically include: lithium nitrate (LiNO) 3 ) Lithium bis (trifluoromethylsulfonyl) imide (LiTFSI), lithium 1,2, 3-hexafluoropropane-1, 3-disulfonimide (LiHFDF), lithium perchlorate (LiClO) 4 ) One or more of lithium bis (fluorosulfonyl) imide (LiFSI), lithium trifluoroacetate (LiFSA), lithium bis (fluorosulfonyl) trifluoromethylsulfonyl imide (LiFTFSI), lithium (tf) trifluoromethane sulfonate (LiTf), lithium bis (pentafluoroethane) sulfonyl imide (LiBETI).
The nonaqueous organic solvent includes: methyl Propyl Ether (MPE), which may further include Acetonitrile (AN), ethylene glycol dimethyl ether (DME), 1, 3-Dioxolane (DOL), dimethoxymethane (MMA), tetrahydrofuran (THF), methyl tetrahydrofuran (mehf), diethyl ether (EE), methyl tert-butyl ether (MTBE), methyl n-butyl ether (MBE), propyl ether (DE), isopropyl ether (IPE), n-Pentane (PE), n-Hexane (HE), n-Heptane (HEP), n-Octane (OCT), fluorinated solvents corresponding to ether solvents among the above solvents, and one or more of isomers or fluorinated systems corresponding to AN alkane solvent among the above solvents.
In order to better understand the technical scheme provided by the invention, the ultralow-density electrolyte and the battery performance of the ultralow-density electrolyte applied to the lithium-sulfur battery are respectively described in the following specific examples.
First, we devised a comparative example for performance comparison with the following examples. The comparative example used a conventional electrolyte to synthesize a lithium sulfur battery.
Comparative example 1
The electrolyte provided in this comparative example 1 and the lithium sulfur secondary battery electrode were prepared as follows:
(1) With commercial electrolyte (1M LiTFSI+2wt%LiNO) 3 +DME/DOL (1:1)) was used as electrolyte for the lithium sulfur experiment, 50 μm ultrathin lithium strip was used as negative electrode, carbon-coated aluminum foil was used as current collector, polypropylene PP was used as diaphragm, mo 6 S 8 +S 8 The composite material of +graphene nanoplatelets (GNs) +carbon nanotubes (CNTs) (mass ratio 20:60:10:10) is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material.
(2) And (2) standing the battery obtained in the step (1) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Comparative example 2
The electrolyte provided in this comparative example 2 and the lithium sulfur secondary battery electrode were prepared as follows:
(1) The high-concentration electrolyte (7M LiTFSI+DME/DOL (1:1)) reported in the literature is used as electrolyte of the lithium sulfur experiment, a 50 mu m ultrathin lithium belt is used as a negative electrode, a carbon-coated aluminum foil is used as a current collector, polypropylene PP is used as a diaphragm, and Mo is used as a diaphragm 6 S 8 +S 8 The composite material of +graphene nanoplatelets (GNs) +carbon nanotubes (CNTs) (mass ratio 20:60:10:10) is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material.
(2) And (2) standing the battery obtained in the step (1) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Comparative example 3
The electrolyte provided in this comparative example 3 and the lithium sulfur primary battery electrode were prepared as follows:
(1) With commercial electrolyte (1M LiTFSI+2wt%LiNO) 3 +DME/DOL (1:1)) is used as electrolyte of the lithium sulfur experiment, a 40 μm ultrathin lithium belt is used as a negative electrode, a carbon-coated aluminum foil is used as a current collector, polypropylene PP is used as a diaphragm, and a S/C ratio is used as a positive electrode material to assemble the soft package battery of the lithium sulfur 1Ah by using a 75:25 (carbon comprises 60% ketjen black and 40% multi-wall carbon nano tubes) composite material.
(2) And (2) standing the battery obtained in the step (1) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Comparative example 4
The electrolyte provided in this comparative example 4 and the lithium sulfur primary battery electrode were prepared as follows:
(1) The high-concentration electrolyte (7M LiTFSI+DME/DOL (1:1)) is used as the electrolyte in the experiment, a 40 mu m ultrathin lithium belt is used as a negative electrode, a carbon-coated aluminum foil is used as a current collector, polypropylene PP is used as a diaphragm, and a S/C ratio is used as a positive electrode material to assemble the soft package battery of lithium sulfur 1Ah by using a 75:25 (carbon comprises 60% ketjen black and 40% multi-wall carbon nano tubes) composite material.
(2) And (2) standing the battery obtained in the step (1) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 1
The embodiment provides a LiTFSI/LiNO 3 Preparation of MPE/DME ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LITFSI and 0.4M LiNO were taken, respectively 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) Respectively taking a certain amount of MPE and DME according to the volume ratio of 5:5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte which is 0.825g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The composite material of +graphene nanoplatelets (GNs) +carbon nanotubes (CNTs) (mass ratio 20:60:10:10) is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The results of the electrochemical performance test of this example 1 and comparative example 1 are shown in FIG. 3. The test result data are detailed in table 1 below.
In this embodiment, we prefer to use LiNO in view of electrolyte density and ionic conductivity 3 The configuration of the double salt of LiTfSi as the lithium salt of the ultra-light electrolyte not only can provide effective lithium ion conductivity on the basis of low density, but also can form a stable SEI film on the surface of the metal lithium, thereby effectively inhibiting the growth of lithium dendrites.
Example 2
The embodiment provides a LiFSI/LiNO 3 Preparation of MPE/DME/DOL ultra-low density electrolyte and performance test for application in secondary batteries.
(1) In a glove box filled with argon, 0.2M LIFSI and 0.4M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4.5:0.5, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.836g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 3
The embodiment provides a LiFSI/LiNO 3 Preparation of MPE/DME/MTBE ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LIFSI and 0.4M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, MTBE is respectively taken according to the volume ratio of 4:4:2, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.813g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 4
The embodiment provides a preparation method of LiTFSI/LiHFDF-MPE/DME/DOL ultra-low density electrolyte and a performance test applied to a secondary battery.
(1) In a glove box filled with argon, respectively taking 0.15M LIFSI and 0.15M LiHFDF, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4.5:0.5, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.845g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 5
The embodiment provides a preparation method of LiTFSI/LiNO3-MPE/DME/MTBE ultra-low density electrolyte and a performance test applied to a secondary battery.
(1) In a glove box filled with argon, respectively taking 0.15M LIFSI and 0.2M LiHFDF, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) A certain amount of MPE, DME, MTBE is respectively taken according to the volume ratio of 4.5:4.5:1.0, placed into a beaker, fully stirred and mixed, and then poured into a quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.818g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 6
The embodiment provides a LiHFDF/LiNO 3 Preparation of MPE/DME/MTBE ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LiHFDF and 0.3M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4:1, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte which is 0.842g/mL;
(4) With 50 μm ultrathin lithium strips as negativeElectrode, carbon-coated aluminum foil as current collector, polypropylene PP as diaphragm, mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 7
The embodiment provides a LiBr/LiNO 3 Preparation of MPE/DME ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.3M LiHFDF and 0.3M LiNO were taken out, respectively 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) Respectively taking a certain amount of MPE and DME according to the volume ratio of 5:5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.834g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 8
The embodiment provides a LiBr/LiNO 3 Preparation of MPE/DME/DOl ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.3M LiHFDF and 0.3M LiNO were taken out, respectively 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4:1, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.839g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 9
The present embodiment provides a LiTf/LiNO 3 Preparation of MPE/DME ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LiTf and 02M LiNO were taken, respectively 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) Respectively taking a certain amount of MPE and DME according to the volume ratio of 5:5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte which is 0.833g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 10
The present embodiment provides a LiClO 4 /LiNO 3 Preparation of MPE/DME/DOl ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LiClO4 and 0.4M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4.5:0.5, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.846g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 11
The present embodiment provides a LiTf/LiNO 3 Preparation of MPE/DME/DOl ultra low density electrolyte and performance testing for use in secondary batteries.
(1) In a glove box filled with argon, 0.2M LiTf and 0.4M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) A certain amount of MPE, DME, DOL is respectively taken according to the volume ratio of 5:4.5:0.5, placed into a beaker, fully stirred and mixed, and then poured into the quantitative bottle of 100ml, so that lithium salt is fully dissolved and mixed;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.845g/mL;
(4) Taking a 50 mu m ultrathin lithium belt as a negative electrode, taking a carbon-coated aluminum foil as a current collector, taking polypropylene PP as a diaphragm and Mo 6 S 8 +S 8 The +GNs+CNTs (mass ratio of 20:60:10:10) composite material is a soft package battery of lithium sulfur 1Ah assembled by the positive electrode material and the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 12
The embodiment provides a LiI/LiNO 3 Preparation of MPE/AN ultra low density electrolyte and performance test for application in primary batteries.
(1) In a glove box filled with argon, 0.2M LiI and 0.3M LiNO were taken separately 3 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) Respectively taking a certain amount of MPE and AN according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte which is 0.824g/mL;
(4) And (3) using a 50-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 13
The embodiment provides a LiI/LiNO 3 Preparation of MPE/AN ultra low density electrolyte and performance test for application in primary batteries.
(1) In a glove box filled with argon, 0.2M LiI and 0.3M LiNO were taken separately 3 Put into 10Fully stirring and mixing in a 0mL quantitative bottle;
(2) Respectively taking a certain amount of MPE and AN according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.795g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 14
The embodiment provides a preparation method of LiI/LiBr-MPE/AN ultra-low density electrolyte and a performance test applied to a primary battery.
(1) In a glove box filled with argon, respectively taking 0.2M LiI and 0.2M LiBr, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) Respectively taking a certain amount of MPE and AN according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.792g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 15
The embodiment provides a preparation method of LiI/LiTf-MTBE/AN ultra-low density electrolyte and a performance test applied to a primary battery.
(1) In a glove box filled with argon, respectively taking 0.2M LiI and 0.1M LiTf, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) Respectively taking a certain amount of MTBE and DME according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle with the volume of 100ml to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.789g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 16
The embodiment provides a LiI/LiClO 4 Preparation of MPE/DME ultra low density electrolyte and performance testing for use in primary batteries.
(1) In a glove box filled with argon, 0.2M LiI and 0.1M LiClO were taken separately 4 Placing the mixture into a quantitative bottle with 100mL, and fully stirring and mixing the mixture;
(2) Respectively taking a certain amount of MPE and AN according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.786g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 17
The embodiment provides a preparation method of LiI/LiWSI-MTBE/AN ultra-low density electrolyte and a performance test applied to a primary battery.
(1) In a glove box filled with argon, respectively taking 0.2M LiI and 0.08M LiFSI, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) Respectively taking a certain amount of MTBE and AN according to the volume ratio of 5.5:4.5, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle with the volume of 100ml to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte of 0.791g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
Example 18
The embodiment provides a preparation method of LiBr/LiWSI-MPE/AN ultra-low density electrolyte and a performance test applied to a primary battery.
(1) In a glove box filled with argon, respectively taking 0.2M LiI and 0.08M LiFSI, putting into a 100mL quantitative bottle, and fully stirring and mixing;
(2) Respectively taking a certain amount of MPE and AN according to the volume ratio of 6:4, putting into a beaker, fully stirring and mixing, and then pouring into the quantitative bottle of 100ml so as to fully dissolve and mix lithium salt;
(3) Testing the density of the electrolyte for 10 times at the constant temperature of 25 ℃ and taking an average value to obtain the density of the electrolyte which is 0.781g/mL;
(4) And (3) using a 40-mu m ultrathin lithium belt as a negative electrode, a carbon-coated aluminum foil as a current collector, polypropylene PP as a diaphragm, and a S/C ratio of 75:25 (carbon comprises 60% Ketjen black and 40% multi-wall carbon nano tubes) composite material as a positive electrode material, and assembling the lithium-sulfur 1Ah soft-package battery with the electrolyte obtained in the step (3).
(5) And (3) standing the battery obtained in the step (4) for 12 hours, and testing the electrochemical performance of the battery on a LAND battery testing system, wherein the multiplying power is 0.1C, and the testing temperature is 25 ℃. The test results are detailed in table 1 below.
TABLE 1
The ultra-light electrolyte provided by the embodiment of the invention has a positive effect on inhibiting polysulfide solubility due to the inhibition effect of multiphase extraction on polysulfide solubility. It should be noted that the proper polysulfide solubility of the ultra-light electrolyte not only helps to suppress the shuttle effect, but also provides a suitable environment for the solid-liquid conversion reaction kinetics of the positive electrode sulfur. The ultra-light electrolyte has higher ionic conductivity of 3.46 mS.cm at 25 DEG C -1 More importantly, it has an ultra low activation energy of 2.29 kj/mole, which results in a reduced energy barrier for ion transfer. In addition, the ultra-light electrolyte exhibits an abnormally low viscosity (0.45 to 1.20 mpa.s) in a wide temperature range of 0 to 50 ℃ and has a small fluctuation, which is much lower than the viscosity (1.73 to 3.11 mpa.s) of the conventional electrolyte and the viscosity (40 to 887 mpa.s) of the high-concentration electrolyte, thereby exhibiting excellent wettability to the porous separator and the electrode, which is advantageous for improving the rate performance of the active material.
The ultra-light electrolyte provided by the invention can still keep higher ion conductivity (3.73-4.74mS·cm -1 ) And moderate viscosity (0.55-2.37 MPa.S) -1 ). This will facilitate the efficient ingress of polysulfide dissolved in the electrolyte into the electrode pores, allowing the polysulfide to be fully reduced, thus achieving rapid transport of lithium ions and polysulfide actives that remain in lean conditions. Therefore, the effective redistribution of active substances in the charge and discharge processes of the lithium-sulfur battery is effectively improved, and the high-sulfur utilization rate can be realized.
The invention provides a novel ultralow-density electrolyte for solving the problem of high mass fraction of an inactive electrolyte in a lithium-sulfur full battery. The result shows that compared with the conventional electrolyte, the ultra-low density electrolytic solution provided by the invention has the advantages that the weight per unit volume is reduced by 30%, the ultra-low density electrolytic solution has good compatibility with lithium metal, the weight ratio of the electrolyte in the lithium-sulfur battery can be greatly reduced, the high sulfur utilization rate is maintained under the lean solution condition, and the energy density can be improved by more than 20% by introducing the ultra-low density electrolytic solution provided by the invention into the lithium-sulfur battery.
The ultralow-density electrolyte provided by the embodiment of the invention can greatly reduce the weight proportion of the electrolyte in the lithium-sulfur full battery under the condition of the same E/S ratio, thereby effectively improving the overall energy density of the lithium-sulfur battery and effectively improving the cycle stability of the lithium-sulfur battery.
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (10)
1. An ultra-low density electrolyte, characterized in that the density of the ultra-low density electrolyte is less than 0.9g/ml; the ultra-low density electrolyte comprises lithium salt and a nonaqueous organic solvent;
wherein, the single molecular structure of the nonaqueous organic solvent contains at most two nucleophilic sites and/or at most three fluorine atoms, the length of the main carbon chain is not more than 7 carbon atoms, and at most two alkane branched structures are contained;
the dielectric constant of the non-aqueous organic solvent is less than 7, so that the dissociation or dissolution of the polysulfide in the non-aqueous organic solvent is inhibited under the limit of the polar functional group;
in the ultralow-density electrolyte, the total concentration range of lithium salt is between 0.01M and 1.2M.
2. The ultra-low density electrolyte according to claim 1, wherein the non-aqueous organic solvent comprises at least one ether or alkane having a density of less than 0.85g/ml and a corresponding fluorinated solvent, and the ether or alkane having a density of less than 0.85g/ml and the corresponding fluorinated solvent account for 20% -90% of the total volume of the non-aqueous organic solvent.
3. The ultra-low density electrolyte of claim 2, wherein the ratio of the density to the solvent density of the ultra-low density electrolyte is 1.1 or less and has an ionic conductivity of > 1mS/cm at a concentration of the lithium salt < 1.0M in the ultra-low density electrolyte.
4. The ultra-low density electrolyte of claim 1, wherein the lithium salt comprises: lithium nitrate (LiNO) 3 ) Lithium iodide (LiI), lithium bromide (LiBr), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI), lithium 1,2, 3-hexafluoropropane-1, 3-disulfonate imide (LiHFDF), lithium perchlorate (LiClO) 4 ) One or more of lithium bis (fluorosulfonyl) imide (LiFSI), lithium trifluoroacetate (LiFSA), lithium bis (fluorosulfonyl) trifluoromethylsulfonyl imide (LiFTFSI), lithium (tf) trifluoromethane sulfonate (LiTf), lithium bis (pentafluoroethane) sulfonyl imide (LiBETI).
5. The ultra-low density electrolyte of claim 4, wherein the lithium salt specifically comprises: liNO 3 And LiTFSI.
6. The ultra-low density electrolyte of claim 1, wherein the non-aqueous organic solvent comprises: one or more of Methyl Propyl Ether (MPE), a mixed solvent of Methyl Propyl Ether (MPE) and a first solvent, a mixed solvent of Methyl Propyl Ether (MPE) and a second solvent, and a mixed solvent of Methyl Propyl Ether (MPE) and a third solvent;
the first solvent comprises: one or more of ethylene glycol dimethyl ether (DME), acetonitrile (AN), 1, 3-Dioxolane (DOL), dimethoxymethane (MMA), tetrahydrofuran (THF), methyltetrahydrofuran (mehf), diethyl ether (EE), methyl tert-butyl ether (MTBE), methyl n-butyl ether (MBE), propyl ether (DE), isopropyl ether (IPE), n-Pentane (PE), n-Hexane (HE), n-Heptane (HEP), n-Octane (OCT);
the second solvent comprises: one or more of ethylene glycol dimethyl ether (DME), diethyl ether (EE), methyl tert-butyl ether (MTBE), methyl n-butyl ether (MBE), propyl ether (DE), isopropyl ether (IPE) fluorinated solvents;
the third solvent comprises: one or more of dimethoxymethane (MMA), n-Pentane (PE), n-Hexane (HE), n-Heptane (HEP), and n-Octane (OCT) corresponding isomers or fluorinated systems.
7. The ultra-low density electrolyte of claim 1, wherein the viscosity of the ultra-low density electrolyte is between 0.45 mpa-sec and 1.20 mpa-sec at 25 ℃.
8. A lithium sulfur battery comprising the ultra low density electrolyte of any one of claims 1-7; the lithium sulfur battery includes a lithium sulfur primary battery or a lithium sulfur secondary battery.
9. The lithium sulfur battery of claim 8 wherein the positive electrode material of the lithium sulfur battery comprises Mo 6 S 8 With TiS 2 Is a composite material of one or two of S, wherein the Mo 6 S 8 With TiS 2 Is used for inhibiting the shuttle effect in the lithium-sulfur battery and simultaneously playing an electrocatalytic role.
10. The lithium sulfur battery of claim 8 wherein the positive electrode material of the lithium sulfur battery further comprises a conductive carbon nanotube and graphene composite as a conductive additive.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011236792.4A CN114464891B (en) | 2020-11-09 | 2020-11-09 | Ultralow-density electrolyte and lithium sulfur battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011236792.4A CN114464891B (en) | 2020-11-09 | 2020-11-09 | Ultralow-density electrolyte and lithium sulfur battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114464891A CN114464891A (en) | 2022-05-10 |
| CN114464891B true CN114464891B (en) | 2023-05-02 |
Family
ID=81404698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011236792.4A Active CN114464891B (en) | 2020-11-09 | 2020-11-09 | Ultralow-density electrolyte and lithium sulfur battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114464891B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115064762A (en) * | 2022-07-28 | 2022-09-16 | 蜂巢能源科技股份有限公司 | Lithium ion battery |
| CN115763950A (en) * | 2022-11-28 | 2023-03-07 | 安徽工业大学 | Electrolyte of lithium-sulfur battery without negative electrode and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103718372A (en) * | 2011-07-18 | 2014-04-09 | 株式会社Lg化学 | Non-aqueous electrolyte and lithium secondary battery using same |
| CN105074968A (en) * | 2013-09-11 | 2015-11-18 | 株式会社Lg化学 | Lithium electrode and lithium secondary battery comprising same |
| CN106848156A (en) * | 2017-03-07 | 2017-06-13 | 南京航空航天大学 | Lithium-sulfur cell diaphragm material and its application |
| CN108933274A (en) * | 2017-05-26 | 2018-12-04 | 中国科学院上海硅酸盐研究所 | A kind of lithium-sulfur cell electrolyte and its application |
| CN109659493A (en) * | 2018-12-26 | 2019-04-19 | 国联汽车动力电池研究院有限责任公司 | It is a kind of comprising solid electrolyte, low porosity cathode and application the cathode lithium battery |
| CN111668550A (en) * | 2020-06-22 | 2020-09-15 | 中航锂电技术研究院有限公司 | Lithium-sulfur battery |
-
2020
- 2020-11-09 CN CN202011236792.4A patent/CN114464891B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103718372A (en) * | 2011-07-18 | 2014-04-09 | 株式会社Lg化学 | Non-aqueous electrolyte and lithium secondary battery using same |
| CN105074968A (en) * | 2013-09-11 | 2015-11-18 | 株式会社Lg化学 | Lithium electrode and lithium secondary battery comprising same |
| CN106848156A (en) * | 2017-03-07 | 2017-06-13 | 南京航空航天大学 | Lithium-sulfur cell diaphragm material and its application |
| CN108933274A (en) * | 2017-05-26 | 2018-12-04 | 中国科学院上海硅酸盐研究所 | A kind of lithium-sulfur cell electrolyte and its application |
| CN109659493A (en) * | 2018-12-26 | 2019-04-19 | 国联汽车动力电池研究院有限责任公司 | It is a kind of comprising solid electrolyte, low porosity cathode and application the cathode lithium battery |
| CN111668550A (en) * | 2020-06-22 | 2020-09-15 | 中航锂电技术研究院有限公司 | Lithium-sulfur battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114464891A (en) | 2022-05-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang et al. | Challenges and future perspectives on sodium and potassium ion batteries for grid-scale energy storage | |
| Liu et al. | Ionic liquids for high performance lithium metal batteries | |
| Lux et al. | Lithium insertion in graphite from ternary ionic liquid–lithium salt electrolytes: II. Evaluation of specific capacity and cycling efficiency and stability at room temperature | |
| CN108292782B (en) | Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same | |
| JP4423277B2 (en) | Lithium secondary battery | |
| Pang et al. | A novel dimethyl sulfoxide/1, 3-dioxolane based electrolyte for lithium/carbon fluorides batteries with a high discharge voltage plateau | |
| CN114464891B (en) | Ultralow-density electrolyte and lithium sulfur battery | |
| CN108288728A (en) | It is a kind of adaptation silicon carbon material lithium-ion battery electrolytes and its application | |
| JP4626020B2 (en) | Non-aqueous electrolyte secondary battery | |
| CN106025270A (en) | Electrochemical energy storage device | |
| Su et al. | Liquid electrolytes for low-temperature lithium batteries: main limitations, current advances, and future perspectives | |
| CN105140558A (en) | High-pressure electrolyte of lithium ion battery and preparation method thereof | |
| CN113363586A (en) | Lithium battery electrolyte and application thereof in lithium battery | |
| Liu et al. | Improving the electrochemical performance of lithium-sulfur batteries by interface modification with a bifunctional electrolyte additive | |
| KR20150049794A (en) | A cathode for lithium sulfur battery and a method for preparing thereof | |
| CN113823839A (en) | Electrolyte and sodium ion battery containing same | |
| CN111211356B (en) | Lithium secondary battery electrolyte containing solid electrolyte and application thereof | |
| JP4901089B2 (en) | Nonaqueous electrolyte secondary battery | |
| CN116666754A (en) | Novel additive of sodium ion battery and sodium ion battery | |
| KR20080040031A (en) | Ion-conductive material and use thereof | |
| KR20050039231A (en) | Organic electrolytic solution and lithium battery using the same | |
| CN111430799B (en) | High-voltage electrolyte for lithium nickel manganese oxide positive electrode material | |
| CN106785023A (en) | A kind of lithium ion battery silicon substrate/silicon-carbon composite cathode material electrolyte system | |
| Kim et al. | Study on urea precursor effect on the electroactivities of nitrogen-doped graphene nanosheets electrodes for lithium cells | |
| CN105609878A (en) | High-voltage electrolyte for lithium-ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |