CN114914543A - Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery - Google Patents
Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery Download PDFInfo
- Publication number
- CN114914543A CN114914543A CN202210501351.5A CN202210501351A CN114914543A CN 114914543 A CN114914543 A CN 114914543A CN 202210501351 A CN202210501351 A CN 202210501351A CN 114914543 A CN114914543 A CN 114914543A
- Authority
- CN
- China
- Prior art keywords
- group
- electrolyte
- lithium
- additive
- fluorine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses an electrolyte additive for efficiently inhibiting dendritic crystals, application thereof and a lithium metal secondary battery, and the electrolyte additive and the lithium metal secondary battery with the same structural characteristic are obtained, wherein the structural formula of the high-fluorine amphoteric molecule is C n F 2n+1 G, the structural general formula is as follows:
wherein G is a lyophilic group, including but not limited to an ionic hydrophilic group; and n is 4 to 20, and represents a highly fluorine-substituted long alkyl chain as a lyophobic group. The additives can be classified into anionic, cationic, nonionic, etc. according to the difference of charges of the G functional group in the dissociation state. The invention also provides the use of the compound as an electrolyte additive in lithium metal secondaryApplication in batteries. The electrolyte additive disclosed by the invention can efficiently realize Solid Electrolyte Interface (SEI) fluorination under a small using amount so as to promote uniform deposition of lithium in compact particles, inhibit formation of lithium dendrites and improve the cycle life and coulombic efficiency of a metal lithium cathode.
Description
Technical Field
The invention belongs to the field of lithium metal secondary batteries, and particularly relates to an electrolyte additive for efficiently inhibiting dendritic crystals and application thereof in a lithium metal secondary battery.
Background
The lithium ion battery is widely applied to various aspects of national economy, and the nation vigorously develops electric automobiles, but at present, the lithium ion battery is difficult to meet the aim that the energy density of a power battery monomer reaches 500Wh/kg in a long term, the main reason is that the theoretical gram capacity of the negative electrode material graphite is lower and is only 372mAh/g, and the actual energy density of the battery is often less than 300 Wh/kg.
The standard hydrogen potential of lithium metal is only-3.14V at the lowest, the mass specific capacity is as high as 3860mAh/g, and the volume specific capacity can contribute 2277mAh/cm 3 The energy density of the lithium metal negative electrode secondary battery is increased to a level of 500 Wh/kg. The lighter and smaller secondary battery device can greatly improve the cruising ability of mobile electronic equipment and new energy automobiles. The challenges facing lithium metal anodes are mainly three: firstly, the electrolyte has active chemical properties, and is easy to generate side reaction with the electrolyte in the circulating process, so that the capacity is attenuated; secondly, dendritic crystal is generated, after a certain current density is reached, the uneven deposition of lithium is gradually developed into dendritic crystal, so that the cycle life of the battery is shortened, and even a series of safety problems are caused; and three is a relatively infinite volume expansion. Avoiding lithium dendrite formation and stabilizing the negative electrode/electrolyte interface are key to promote the application of metallic lithium negative electrodes.
Numerous studies have shown that if an SEI film containing LiF as a representative component can be formed on the surface of lithium metal, dendrite formation can be greatly slowed down. For example, Lang et al observed a distinct LiF-forming layer under a scanning electron microscope by soaking a pure lithium sheet in pvdf-dimethylformamide for 5-10s, and the pretreated lithium sheet exhibited good cycling stability and high current resistance when assembled into a battery (Lang, j., et al. Many researchers add a fluorine-containing auxiliary agent (fluorination auxiliary agent) to the electrolyte, such as a high-concentration fluorine-containing lithium salt (such as lithium bistrifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, etc.) or a high-quality fraction fluorine-containing solvent (such as fluoroethylene carbonate), so that the lithium metal negative electrode can obtain better protection effect in the process of electric cycle. Patent CN108539272A discloses a lithium fluoride-containing salt of 15M, up to 10 wt% of metal halide (including AgF, CuF) 2 Etc.) additive compositionAn electrolyte system; patent CN110416615A discloses an electrolyte system in which fluorine-containing lithium salt is dissolved in ester or ether solvent at a concentration of up to 10M. Although these methods can alleviate the growth of dendrites to some extent and prolong the service life of the lithium metal battery, when the amount of the fluorine-containing additive is too large, the viscosity of the electrolyte is increased, the conductivity is decreased, the wettability to the separator and the electrode is decreased, the internal resistance is increased, and the battery performance is deteriorated. Moreover, the fluorination aids are costly and not suitable for commercial applications. Therefore, the finding of the fluorine-containing additive which can effectively realize the fluorination of the solid electrolyte membrane (SEI) under a small addition amount has important application value.
Disclosure of Invention
The invention aims to provide an electrolyte additive for efficiently inhibiting dendritic crystals, application and a lithium metal secondary battery, aiming at solving the problems in the prior art, and the High Fluorinated Amphoteric Molecule (HFAM) additive with a common structure characteristic is obtained, so that the fluorination of a solid electrolyte membrane (SEI) is efficiently realized under a small using amount, the uniform deposition of lithium in a dense granular state is promoted, the formation of lithium dendritic crystals is inhibited, and the cycle life and the coulombic efficiency of a metal lithium cathode are improved.
The electrolyte additive for efficiently inhibiting dendritic crystals is a high-fluorine-containing amphoteric molecule with the structural formula of C n F 2n+1 G, the structural general formula is as follows:
wherein G is a lyophilic group, including but not limited to an ionic hydrophilic group; and n is 4 to 20, and represents a highly fluorine-substituted long alkyl chain as a lyophobic group. The additives can be classified into anionic, cationic, nonionic, etc. according to the difference of charges of the G functional group in the dissociation state.
Further, when the lyophilic group G is a cationic group, G is selected from at least one of sulfonamide cationic group and carboxylic acid amide cationic group (structural formula is shown in the specification), wherein M is I - 、Br - 、Cl - One of (1), R 1 、R 2 、 R 3 、R 4 Are all alkyl chains; preferably, when G is a cationic group, the high-fluorinated amphoteric molecular additive is selected from at least one of perfluorooctyl quaternary amine iodide, perfluorononyl sulfonamide bromide.
Further, when the lyophilic group G is an anionic group, G is selected from at least one of carboxylic acid group and sulfonic acid group (structural formula shown in the specification), wherein M is H + 、Li + 、Na + 、K + 、Cs + 、NH 4 + 、1/2(Ca 2+ 、Mg 2+ 、Zn 2+ 、 N(CH 3 ) 4 + 、N(C 2 H 5 ) 4 + 、N(C 3 H 7 ) 4 + 、N(C 4 H 9 ) 4 + One of (1); preferably, when G is an anionic group, the high-fluorine amphoteric molecule additive is at least one selected from potassium perfluorooctyl sulfonate and sodium perfluorooctyl carboxylate.
Further, when the lyophilic group G is a nonionic group, G is selected from at least one of an ethanolamine group and an amine oxide group (the structural formula is shown as the following), wherein R is 1 、R 2 、R 3 Are all alkyl chains; preferably, when G is a nonionic group, the high-fluorine amphoteric molecule additive is selected from at least one of perfluorooctylsulfonyl ethanolamine and perfluorooctylsulfonyl diethanolamine.
Further, the electrolyte additive can be at least one or more than two of cationic, anionic and nonionic compound mixtures.
The invention also provides an electrolyte based on the additive, which comprises a lithium salt, an organic solvent and the electrolyte additive.
The molar concentration of the electrolyte additive is 1 mmol/L-100 mmol/L.
In the electrolyte, the electrolyte additive can be a compound of an anion type and a cation type, and preferably, the compound molar concentration ratio of the anion type to the cation type is 1: 1.
the electrolyte solution is characterized in that the organic solvent is at least one selected from dimethyl carbonate (DMC), diethyl carbonate (DEC), Ethylene Carbonate (EC), Propylene Carbonate (PC), Vinylene Carbonate (VC), ethylene glycol dimethyl ether (DME), fluoroethylene carbonate (FEC), 1, 3-Dioxolane (DOL), diethylene glycol dimethyl ether (BME), tetraethylene glycol dimethyl ether (TEGDME) and diphenyl ether (DPE).
The electrolyte, wherein the lithium salt is selected from lithium hexafluorophosphate (LiPF) 6 ) Lithium bistrifluoromethanesulfonylimide (LiTFSI), lithium tetrafluoroborate (LiBF) 4 ) Lithium hexafluoroarsenate (LiAsF) 6 ) Lithium perchlorate (LiClO) 4 ) At least one of (1).
In the electrolyte, the molar concentration of the lithium salt is 0.1-8.0 mol/L.
The invention also provides a preparation method of the electrolyte, which comprises the following steps:
(1) drying the high fluorine additive powder for 12h at 60 ℃ under vacuum;
(2) and adding the high-fluorine additive into the lithium salt electrolyte in a glove box protected by argon atmosphere with water and oxygen content less than or equal to 0.1ppm, and fully and uniformly stirring to obtain the electrolyte.
The invention also provides application of the high-fluorine amphoteric molecule in a lithium metal secondary battery, wherein the application is used as an electrolyte additive.
In the application, the high-fluorine amphoteric molecule is used as an electrolyte additive, and the molar concentration of the high-fluorine amphoteric molecule in the electrolyte is 1 mmol/L-100 mmol/L; the negative electrode material of the lithium metal secondary battery is a lithium metal or lithium alloy electrode material using metal lithium as an active material.
The invention also provides application of the electrolyte in manufacturing a lithium metal secondary battery, wherein a negative electrode material of the secondary lithium metal battery is a lithium metal or lithium alloy electrode material taking metal lithium as an active substance.
The invention also provides a lithium metal secondary battery based on the electrolyte, which comprises the electrolyte, a positive electrode, a spring plate, a gasket, a diaphragm and a negative electrode.
The lithium metal secondary battery has a positive electrode material selected from LiFePO 4 、LiCoO 2 、LiNi a Co b Mn c O 2 (NCM ternary cathode Material), LiNi a Co b Al c O 2 (NCA ternary positive electrode material) and metal sulfide; the proportion of the ternary material satisfies the relation: a + b + c is 1.
In the lithium metal secondary battery, the negative electrode material is selected from pure metal lithium or lithium alloy electrode material Li taking metal lithium as an active material m X is one of lithium-philic metal elements such as Si, Sn, In, Ag and the like.
The preparation of the electrolyte and the assembly of the lithium metal secondary battery are carried out in a glove box filled with argon, and the oxygen content is less than 0.1ppm and the water content is less than 0.1 ppm.
Compared with the prior art, the invention has the following beneficial effects:
1. the high-fluorine amphoteric molecular additive provided by the invention has strong surface activity, contains a large amount of fluorine atoms in molecules, can form an SEI (solid electrolyte interphase) film with a compact structure and rich in LiF (lithium ion exchange membrane) on the surface of a lithium cathode under the condition of using an additive with extremely low concentration (<100mmol/L), effectively passivates the surface of lithium, protects the surface of lithium metal, can promote the formation of large-particle lithium deposition products in an electrical cycle process, induces lithium ions to be densely and uniformly deposited in particles, inhibits dendritic crystal formation, improves the cycle life and the coulombic efficiency of a metal lithium cathode, and has good application prospect in a secondary battery with lithium metal as the cathode.
2. The high-fluorine amphoteric molecular additive provided by the invention can be oxidized and decomposed on the positive electrode side to form a stable positive electrode passive film (CEI), can improve the voltage working window of a battery, further improve the energy density of the battery, obviously reduce the surface tension of electrolyte and improve the wettability of the electrolyte to a diaphragm and an electrode.
3. The high-fluorine amphoteric molecular additive used in the invention has good solubility in both carbonate electrolyte and ether electrolyte, can obviously play a role under the condition of extremely small dosage, has low cost and simple operation, has strong process compatibility with the existing lithium secondary battery, and is suitable for large-scale popularization.
Drawings
FIG. 1 shows Li | | | Cu cell of example 1 at 1mA/cm 2 SEM images after 2h of current density deposition.
FIG. 2 shows comparative example 1Li | | | Cu cell at 1mA/cm 2 SEM images after 2h of current density deposition.
FIG. 3 shows Li cells of examples 1 and 2 and comparative example 1 at 0.5mA/cm 2 ，1mAh/cm 2 Voltage-time diagram of charge and discharge.
Detailed Description
The invention is further illustrated by the following examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make certain insubstantial modifications and adaptations of the present invention based on the above disclosure and still fall within the scope of the present invention.
In the following examples, the application of the electrolytic liquid system in lithium metal batteries includes the preparation of the electrode sheet, the assembly of the batteries and the corresponding test conditions of the batteries. The highly fluorinated amphoteric molecular additives and the electrolyte components used in the examples are commercially available.
Preparing a lithium negative pole piece:
pressing pure metal lithium and lithium-tin alloy materials together with a copper foil current collector, and punching into a wafer;
assembling the battery:
(1) lithium-lithium symmetric battery: lithium sheets and lithium alloy sheets are used as electrodes, namely Li | | | Li and Li-Sn | | | Li-Sn, a diaphragm is Celgard 2500, and according to the embodiment, the electrolyte is filled with argon, and a CR2025 symmetrical button cell (hereinafter referred to as a symmetrical cell) is manufactured in a glove box with the water and oxygen contents lower than 0.01 ppm.
(2) Lithium copper button cell: the prepared lithium sheet and lithium alloy sheet are used as working electrodes, namely Li | | | Cu or Li-Sn | | Cu is matched with a counter electrode copper foil, different electrolytes are selected according to different embodiments, a diaphragm is celgard 2500, and a CR2025 lithium copper button cell (hereinafter referred to as a lithium copper cell) is manufactured in a glove box which is filled with argon and has water and oxygen contents lower than 0.1 ppm.
The symmetric cell test condition is that the activation current is 0.1mA/cm 2 The primary charge and discharge is 20min, and the constant current charge and discharge current density is 0.5mA/cm 2 Or 1mA/cm 2 The charge and discharge time was 4 hours.
The test condition of the lithium-copper battery is that 0.2mA/cm is adopted 2 After three cycles of current activation, 2.852mAh of lithium was previously deposited on the copper foil to eliminate the effect of the copper foil on lithium deposition/electrolysis, and then at 0.5mA/cm 2 ，0.5mAh/cm 2 Under the condition of (1), charging and discharging are carried out for 100 circles under constant current, and finally, the lithium on the copper foil is completely electrolyzed after charging to 1V.
Example 1
0.0500g of potassium perfluorooctyl sulfonate (C) 8 F 17 SO 3 K, hereinafter designated as HFAM1) was dissolved in 9.5mL of 1mol/L LiPF 6 And adding 0.5mL of FEC into the conventional electrolyte with the volume ratio of EC/EMC/DMC (1: 1: 1), wherein the molar concentration of the anionic high-fluorine amphoteric additive is 10mmol/L, and the volume fraction of FEC is 5%.
Assembling Li-Sn | Li-Sn, Li | Li symmetrical batteries and Li-Sn | Cu, Li | Cu batteries, respectively adding 5 drops of the prepared electrolyte by using a dropper, and packaging. Standing for 2h in a constant-temperature 20 ℃ blue test box, and then carrying out subsequent electrochemical test.
At 0.5mA/cm 2 ，1mAh/cm 2 Under the condition, the Li symmetrical battery can stably circulate for 200 circles. The Li | | Cu battery can effectively circulate for 50 circles and storesThe Lorentz efficiency was 92.0%.
Example 2
0.0675g of perfluorooctyl quaternary ammonium iodide (C) 14 H 16 F 17 IN 2 O 2 S; hereinafter referred to as HFAM2) was dissolved in 9.5mL of 1mol/L LiPF 6 And adding 0.5mL of FEC into the + EC/EMC/DMC (the volume ratio of the three is 1: 1: 1) electrolyte, wherein the molar concentration of the cationic high-fluorine amphoteric additive is 10mmol/L, and the volume fraction of the FEC is 5%.
When assembling Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Sn | Cu, Li | Cu battery, respectively adding 5 drops of the prepared electrolyte by a dropper, and finally packaging. Standing for 2h in a constant temperature 20 ℃ blue electricity test box, and then carrying out subsequent electrochemical test.
At 0.5mA/cm 2 ，1mAh/cm 2 Under the condition, the Li symmetrical battery can stably circulate for 200 circles. The Li | | Cu battery can effectively circulate for 60 circles, and the coulombic efficiency is 93.4%.
Example 3
0.1000g of HFAM1 was dissolved in 9.5mL of 1mol/L LiPF 6 And adding 0.5mL of FEC into the conventional electrolyte with the volume ratio of + EC/EMC/DMC (1: 1: 1), wherein the molar concentration of the anionic high-fluorine amphoteric additive is 20mmol/L, and the volume fraction of FEC is 5%.
And 5 drops of the prepared electrolyte are respectively added by a dropper when the Li-Sn | Li-Sn, Li | Li symmetrical battery and the Li-Sn | Cu battery are assembled, and finally the packaging is carried out. Standing for 2h in a constant-temperature 20 ℃ blue test box, and then carrying out subsequent electrochemical test.
Example 4
0.0500g of HFAM1 was dissolved in 9.5mL of 11 mol/L LiPF together with 0.0675g of HFAM2 6 And adding 0.5mL of FEC into the conventional electrolyte of + EC/EMC/DMC (the volume ratio of the three is 1: 1: 1), wherein the molar concentration of the composite high fluorine amphoteric additive is 20mmol/L, and the volume fraction of FEC is 5%.
Assembling Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Li 22 Sn 5 And 5 drops of the prepared electrolyte are added by a dropper when the battery is a Li Cu battery, and finally the battery is packaged. In a constant temperature 20 ℃ blue test boxStanding for 2h, and then carrying out subsequent electrochemical tests.
Example 5
0.2000g of HFAM1 was dissolved in 9.5mL of 11 mol/L LiPF 6 And adding 0.5mL of FEC into the conventional electrolyte of + EC/EMC/DMC (the volume ratio of the three is 1: 1: 1), wherein the molar concentration of the anionic high-fluorine additive is 40 mmol/L, and the volume fraction of the FEC is 5%.
And 5 drops of the prepared electrolyte are added by a dropper when the Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Sn | Cu battery are used, and finally the packaging is carried out. Standing for 2h in a constant-temperature 20 ℃ blue test box, and then carrying out subsequent electrochemical test.
Example 6
0.0674g of perfluorononyl sulfonamide bromide (C) 9 F 19 SO 2 NH(CH 2 ) 3 N(CH 3 ) 3 Br) was co-dissolved in 9.5mL of 11 mol/L LiPF 6 And adding 0.5mL of FEC into the conventional electrolyte of + EC/EMC/DMC (the volume ratio of the three is 1: 1: 1), wherein the molar concentration of the anionic high-fluorine amphoteric additive is 10mmol/L, and the volume fraction of FEC is 5%.
Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Li 22 Sn 5 And 5 drops of the prepared electrolyte are added by a dropper when the battery is a Cu or Li Cu battery, and finally the battery is packaged. Standing for 2h in a constant-temperature 20 ℃ blue test box, and then carrying out subsequent electrochemical test.
Example 7
0.0500g of perfluorooctylsulfonylethanolamine (C) 8 F 17 SO 2 N(CH 2 CH 2 OH) 2 ) 11 mol/L LiPF dissolved in 9.5mL 6 And adding 0.5mL of FEC into the conventional electrolyte of + EC/EMC/DMC (the volume ratio of the three is 1: 1: 1), wherein the molar concentration of the nonionic high-fluorine amphoteric additive is 10mmol/L, and the volume fraction of the FEC is 5%.
And 5 drops of the prepared electrolyte are added by a dropper when the Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Sn | Cu battery are used, and finally the packaging is carried out. Standing for 2h in a constant-temperature 20 ℃ blue test box, and then carrying out subsequent electrochemical test.
Comparative example 1
9.5mL of 1M LiPF was measured out using a measuring cylinder 6 + EC/EMC/DMC (1: 1: 1 volume ratio of the three) of the conventional electrolyte, and then 0.5mL of FEC, where the molar concentration of the surfactant as an additive was 0mmol/L and the volume fraction of FEC was 5% (hereinafter referred to as blank electrolyte).
And 5 drops of the prepared electrolyte are respectively added by a dropper when the battery is a Li-Sn | Li-Sn, Li | Li symmetrical battery and Li-Sn | Cu, Li | Cu battery, and finally the battery is packaged. Standing for 2h in a constant temperature 20 ℃ blue electricity test box, and then carrying out subsequent electrochemical test. At 0.5mA/cm 2 ，1mAh/cm 2 Under the condition, the Li symmetrical battery can stably circulate for 125 circles. The Li | Cu battery can effectively circulate for 48 circles.
FIG. 1 shows the Li | | | Cu cell of example 1 at 1mA/cm 2 SEM images of current density after 2h deposition; FIG. 2 shows comparative example 1Li | | | Cu cell at 1mA/cm 2 SEM images after 2h of current density deposition. It can be seen that a small amount of HFAM1 was effective in inducing uniform deposition of lithium ions, and the morphology after deposition was denser than that of comparative example 1 using a blank electrolyte.
FIG. 3 shows Li cells of examples 1 and 2 and comparative example 1 at 0.5mA/cm 2 ，1mAh/cm 2 The voltage-time diagram of charging and discharging shows that after the blank electrolyte is circulated for 500 hours, the overpotential obviously rises, which indicates that the dendrite growth for a long time causes the intense polarization in the battery. After the electrolyte of HFAM1 or HFAM2 is added, the overpotential tends to be stable after 700-hour circulation, and no obvious polarization appears, which shows that the additive can effectively prolong the service life of the lithium metal negative electrode.
Claims (10)
1. The electrolyte additive for efficiently inhibiting dendritic crystals is characterized by being a high-fluorinated amphoteric molecule with a structural formula of C n F 2n+1 G, the structural general formula is as follows:
wherein G is a lyophilic group, including but not limited to an ionic hydrophilic group; n is 4 to 20, and represents a highly fluorine-substituted long alkyl chain as a lyophobic group.
2. The electrolyte additive of claim 1 wherein the lyophilic group G is a cationic group, an anionic group, or a nonionic group;
when the lyophilic group G is a cationic group, G is selected from at least one of sulfonamide cationic group and carboxylic acid amide cationic group; when the lyophilic group G is an anionic group, G is selected from at least one of carboxylic acid group and sulfonic acid group; and when the lyophilic group G is a nonionic group, G is selected from at least one of an ethanolamine group and an amine oxide group.
3. The electrolyte additive according to claim 1, wherein when G is a cationic group, G is selected from at least one of sulfonamide cationic groups and carboxylic acid amide cationic groups, wherein M is I - 、Br - 、Cl - One of (1), R 1 、R 2 、R 3 、R 4 Are all alkyl chains;
when G is an anionic group, G is selected from at least one of carboxylic acid group and sulfonic acid group, wherein M is H + 、Li + 、Na + 、K + 、Cs + 、NH 4 + 、1/2(Ca 2+ 、Mg 2+ 、Zn 2+ 、N(CH 3 ) 4 + 、N(C 2 H 5 ) 4 + 、N(C 3 H 7 ) 4 + 、N(C 4 H 9 ) 4 + One of (1);
when G is a nonionic group, G is selected from at least one of ethanolamine group and amine oxide group, wherein R is 1 、R 2 、R 3 Are all alkyl chains;
4. the electrolyte additive of claim 1, wherein when G is a cationic group, the high-fluorinated amphoteric molecule additive is at least one selected from the group consisting of perfluorooctyl quaternary amine iodide, perfluorononyl sulfonamide bromide; when G is an anionic group, the high-fluorine amphoteric molecule additive is selected from at least one of potassium perfluorooctyl sulfonate and sodium perfluorooctyl carboxylate; and when G is a nonionic group, the high-fluorine amphoteric molecule additive is selected from at least one of perfluorooctyl sulfonyl ethanolamine and perfluorooctyl sulfonyl diethanolamine.
5. An electrolyte comprising a lithium salt, an organic solvent and the electrolyte additive of any one of claims 1 to 3.
6. The electrolyte of claim 5, wherein the molar concentration of the electrolyte additive in the electrolyte is 1mmol/L to 100 mmol/L; the organic solvent is at least one selected from dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, vinylene carbonate, ethylene glycol dimethyl ether, fluoroethylene carbonate, 1, 3-dioxolane, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether and diphenyl ether; the lithium salt is selected from at least one of lithium hexafluorophosphate, lithium bistrifluoromethanesulfonylimide, lithium tetrafluoroborate, lithium hexafluoroarsenate and lithium perchlorate; the molar concentration of the lithium salt is 0.1-8.0 mol/L.
7. The method for preparing the electrolyte of claim 5, comprising the steps of:
(1) drying the high fluorine additive powder for 12 hours at 60 ℃ under vacuum;
(2) and adding the high-fluorine additive into the lithium salt electrolyte in a glove box protected by argon atmosphere with water and oxygen content less than or equal to 0.1ppm, and fully and uniformly stirring to obtain the electrolyte.
8. Use of a highly fluorinated amphoteric molecule as an electrolyte additive in a lithium metal secondary battery, said highly fluorinated amphoteric molecule having the structural formula C n F 2n+1 G, the general structural formula is as follows:
wherein G is a lyophilic group, including but not limited to an ionic hydrophilic group; n is 4 to 20, and represents a highly fluorine-substituted long alkyl chain as a lyophobic group.
9. The use according to claim 8, wherein the lyophilic group G is a cationic group, an anionic group or a non-ionic group;
when the lyophilic group G is a cationic group, G is selected from at least one of sulfonamide cationic group and carboxylic acid amide cationic group; when the lyophilic group G is an anionic group, G is selected from at least one of carboxylic acid group and sulfonic acid group; and when the lyophilic group G is a nonionic group, G is selected from at least one of ethanolamine group and amine oxide group.
10. The lithium metal secondary battery according to claim 5, comprising the electrolyte according to claim 4, and a positive electrode, a spring, a gasket, a separator, and a negative electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210501351.5A CN114914543A (en) | 2022-05-09 | 2022-05-09 | Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210501351.5A CN114914543A (en) | 2022-05-09 | 2022-05-09 | Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114914543A true CN114914543A (en) | 2022-08-16 |
Family
ID=82765894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210501351.5A Pending CN114914543A (en) | 2022-05-09 | 2022-05-09 | Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114914543A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115863768A (en) * | 2023-02-22 | 2023-03-28 | 安徽盟维新能源科技有限公司 | Electrolyte and lithium metal battery containing same |
| CN117682972A (en) * | 2024-01-31 | 2024-03-12 | 安徽盟维新能源科技有限公司 | Organic compound containing sulfonamide group and fluorinated group and application thereof |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07282851A (en) * | 1994-04-14 | 1995-10-27 | Sony Corp | Nonaqueous electrolytic secondary battery |
| JPH087923A (en) * | 1994-06-22 | 1996-01-12 | Tokin Corp | Electrolyte for lithium secondary cell |
| JPH1012273A (en) * | 1996-06-25 | 1998-01-16 | Sony Corp | Nonaqueous electrolyte secondary battery |
| JP2002033118A (en) * | 2000-07-14 | 2002-01-31 | Mitsubishi Heavy Ind Ltd | Lithium secondary battery |
| JP2003086241A (en) * | 2001-09-14 | 2003-03-20 | Mitsubishi Heavy Ind Ltd | Lithium secondary battery |
| JP2004079335A (en) * | 2002-08-19 | 2004-03-11 | Nec Corp | Electrolytic solution for secondary battery and secondary battery using it |
| JP2004253296A (en) * | 2003-02-21 | 2004-09-09 | Nec Corp | Electrolyte for secondary battery and secondary battery using it |
| KR20080018850A (en) * | 2006-08-25 | 2008-02-28 | 소니 가부시끼가이샤 | Electrolytic solution and battery |
| JP2008198409A (en) * | 2007-02-09 | 2008-08-28 | Sony Corp | Nonaqueous electrolyte solution and nonaqueous electrolyte solution cell using it |
| CN101826635A (en) * | 2010-04-09 | 2010-09-08 | 广州天赐高新材料股份有限公司 | Polymer electrolyte for lithium battery and manufacturing method of battery thereof |
| CN102484281A (en) * | 2009-08-31 | 2012-05-30 | 三菱化学株式会社 | Nonaqueous electrolyte solution and nonaqueous electrolyte battery using same |
| JP2014164801A (en) * | 2013-02-21 | 2014-09-08 | Shin Kobe Electric Mach Co Ltd | Nonaqueous electrolyte, nonaqueous electrolyte secondary battery using the same, and secondary battery system with nonaqueous electrolyte secondary battery |
| CN107093694A (en) * | 2017-05-17 | 2017-08-25 | 河北金力新能源科技股份有限公司 | A kind of aqueous PVDF coating lithium ions battery diaphragm and preparation method thereof |
| CN110416615A (en) * | 2019-05-15 | 2019-11-05 | 华南理工大学 | A kind of electrolyte and lithium battery inhibiting lithium dendrite growth |
| CN111799444A (en) * | 2020-07-20 | 2020-10-20 | 厦门大学 | Lithium metal negative electrode protection method for improving lithium utilization efficiency |
| WO2022093716A1 (en) * | 2020-10-28 | 2022-05-05 | Enevate Corporation | Symmetrical or asymmetrical alkylsulfonyl imide or cyclic alkylene sulfonylimide salts as cathode additives, electrolyte additives, or si anode additives for si anode-based li-ion cells |
-
2022
- 2022-05-09 CN CN202210501351.5A patent/CN114914543A/en active Pending
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07282851A (en) * | 1994-04-14 | 1995-10-27 | Sony Corp | Nonaqueous electrolytic secondary battery |
| JPH087923A (en) * | 1994-06-22 | 1996-01-12 | Tokin Corp | Electrolyte for lithium secondary cell |
| JPH1012273A (en) * | 1996-06-25 | 1998-01-16 | Sony Corp | Nonaqueous electrolyte secondary battery |
| JP2002033118A (en) * | 2000-07-14 | 2002-01-31 | Mitsubishi Heavy Ind Ltd | Lithium secondary battery |
| JP2003086241A (en) * | 2001-09-14 | 2003-03-20 | Mitsubishi Heavy Ind Ltd | Lithium secondary battery |
| JP2004079335A (en) * | 2002-08-19 | 2004-03-11 | Nec Corp | Electrolytic solution for secondary battery and secondary battery using it |
| JP2004253296A (en) * | 2003-02-21 | 2004-09-09 | Nec Corp | Electrolyte for secondary battery and secondary battery using it |
| KR20080018850A (en) * | 2006-08-25 | 2008-02-28 | 소니 가부시끼가이샤 | Electrolytic solution and battery |
| JP2008198409A (en) * | 2007-02-09 | 2008-08-28 | Sony Corp | Nonaqueous electrolyte solution and nonaqueous electrolyte solution cell using it |
| CN102484281A (en) * | 2009-08-31 | 2012-05-30 | 三菱化学株式会社 | Nonaqueous electrolyte solution and nonaqueous electrolyte battery using same |
| CN101826635A (en) * | 2010-04-09 | 2010-09-08 | 广州天赐高新材料股份有限公司 | Polymer electrolyte for lithium battery and manufacturing method of battery thereof |
| JP2014164801A (en) * | 2013-02-21 | 2014-09-08 | Shin Kobe Electric Mach Co Ltd | Nonaqueous electrolyte, nonaqueous electrolyte secondary battery using the same, and secondary battery system with nonaqueous electrolyte secondary battery |
| CN107093694A (en) * | 2017-05-17 | 2017-08-25 | 河北金力新能源科技股份有限公司 | A kind of aqueous PVDF coating lithium ions battery diaphragm and preparation method thereof |
| CN110416615A (en) * | 2019-05-15 | 2019-11-05 | 华南理工大学 | A kind of electrolyte and lithium battery inhibiting lithium dendrite growth |
| CN111799444A (en) * | 2020-07-20 | 2020-10-20 | 厦门大学 | Lithium metal negative electrode protection method for improving lithium utilization efficiency |
| WO2022093716A1 (en) * | 2020-10-28 | 2022-05-05 | Enevate Corporation | Symmetrical or asymmetrical alkylsulfonyl imide or cyclic alkylene sulfonylimide salts as cathode additives, electrolyte additives, or si anode additives for si anode-based li-ion cells |
Non-Patent Citations (5)
| Title |
|---|
| 云斯宁主编: "《新型能源材料与器件》", 北京：中国建材工业出版社 * |
| 冯建文;胡时光;韩兵;肖映林;邓永红;王朝阳;: "锂金属电池电解液组分调控的研究进展" * |
| 戚世瀚;王华平;何健;刘建东;崔春雨;武明光;李芳;冯跃战;马建民: "用于金属锂电池的全氟烷基磺酸钾盐优化电解液" * |
| 李萌;邱景义;余仲宝;廖红英;李冰川;: "高功率锂离子电池电解液中导电锂盐的新应用" * |
| 王旭尧;刘姝伶;闫晓丹;张灵志;: "单离子导体聚合物电解质研究进展" * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115863768A (en) * | 2023-02-22 | 2023-03-28 | 安徽盟维新能源科技有限公司 | Electrolyte and lithium metal battery containing same |
| CN115863768B (en) * | 2023-02-22 | 2023-04-25 | 安徽盟维新能源科技有限公司 | Electrolyte and lithium metal battery containing same |
| CN117682972A (en) * | 2024-01-31 | 2024-03-12 | 安徽盟维新能源科技有限公司 | Organic compound containing sulfonamide group and fluorinated group and application thereof |
| CN117682972B (en) * | 2024-01-31 | 2024-04-30 | 安徽盟维新能源科技有限公司 | Organic compound containing sulfonamide group and fluorinated group and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20080131772A1 (en) | Electrolytes, electrolyte additives and cells | |
| US20030129498A1 (en) | Electrolyte system and energy storage device using same | |
| KR20110038131A (en) | Nonaqueous electrolyte solution and lithium secondary battery | |
| KR20180057969A (en) | Electrolyte for secondary battery and secondary battery comprising same | |
| JP5062459B2 (en) | Nonaqueous electrolyte secondary battery | |
| CN114639873B (en) | Battery electrolyte, secondary battery and terminal | |
| CN114914543A (en) | Electrolyte additive for efficiently inhibiting dendritic crystal, application thereof and lithium metal secondary battery | |
| CN111934015B (en) | Non-aqueous electrolyte of lithium ion battery and lithium ion battery containing non-aqueous electrolyte | |
| CN115911560A (en) | Electrolyte, secondary battery and electric equipment | |
| CN111313086B (en) | Electrolyte and lithium ion battery | |
| EP3738167A1 (en) | Non-aqueous electrolyte compositions comprising lithium bis(fluorosulfonyl)imide | |
| CN113394450A (en) | Lithium cobaltate high-voltage lithium ion battery non-aqueous electrolyte and lithium ion battery | |
| CN113972397A (en) | Electrolyte for lithium metal secondary battery and application thereof | |
| CN116525940A (en) | Sodium ion battery electrolyte and sodium ion battery | |
| US20230019506A1 (en) | Electrolyte composition with fluorinated acyclic carbonate and fluorinated cyclic carbonate | |
| CN114566712A (en) | High-voltage lithium ion battery electrolyte containing lithium difluorophosphate, preparation method thereof and lithium ion battery | |
| CN115882070A (en) | Electrolyte and lithium metal battery containing same | |
| CN112117492A (en) | Organic ester electrolyte additive, electrolyte containing additive, lithium metal battery and application | |
| CN111354977A (en) | Lithium ion battery electrolyte, preparation method thereof and lithium battery comprising lithium ion battery electrolyte | |
| CN114914544B (en) | Sodium metal battery electrolyte and preparation method thereof | |
| CN112864459B (en) | Electrolyte, preparation method thereof and secondary lithium metal battery | |
| EP4391108A1 (en) | Solid state electrolyte for anode-free metal battery cell | |
| US12148889B2 (en) | Non-aqueous electrolyteincluding lithium bis(fluorosulfonyl)imide, fluorinated acyclic carboxylic acid ester, organic carbonate and electrolyte salt | |
| CN118017006A (en) | Lithium/sodium metal battery electrolyte and preparation method thereof | |
| CN117239238A (en) | Electrolyte and lithium ion battery thereof |
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 |