CN114421008A - Wettability-enhanced lithium ion battery electrolyte and application thereof - Google Patents

Wettability-enhanced lithium ion battery electrolyte and application thereof Download PDF

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CN114421008A
CN114421008A CN202011174011.3A CN202011174011A CN114421008A CN 114421008 A CN114421008 A CN 114421008A CN 202011174011 A CN202011174011 A CN 202011174011A CN 114421008 A CN114421008 A CN 114421008A
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electrolyte
lithium
ion battery
lithium ion
wettability
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黄富强
韩振
毕辉
居亚兰
马文勤
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Shaanxi Zebang Environmental Technology Co ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
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    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
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    • 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
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    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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Abstract

The invention relates to an electrolyte of an wettability-enhanced lithium ion battery and application thereof, wherein the electrolyte of the wettability-enhanced lithium ion battery comprises: solvents, electrolytes and additives; the electrolyte is selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium dioxalate borate, N-dialkyl pyrrolidinium lithium salt, lithium difluorooxalate borate, lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide and lithium N-ethyl pyrrolidinium tetrafluoroborate; the additive is a halogenated polyaromatic ring, and is preferably at least one selected from 1-chloronaphthalene, 1, 4-dichloronaphthalene, 1,2,3, 4-tetrachloronaphthalene, 1-bromonaphthalene, alpha-nitronaphthalene, 1-chloromethylnaphthalene, 1-iodonaphthalene, anthracene and 2-chloroanthracene.

Description

Wettability-enhanced lithium ion battery electrolyte and application thereof
Technical Field
The invention relates to a lithium battery electrolyte, in particular to an wettability-enhanced lithium ion battery electrolyte and application thereof, and belongs to the technical field of lithium battery (lithium ion battery) electrolytes.
Background
The lithium ion battery is used as the most advantageous high-energy chemical power supply, the research on the lithium ion battery is continuously developed in depth and depth all over the world, and an electrolyte system used as an important component of the lithium ion battery is also subjected to continuous development. Research into these components, whether electrolytic lithium salts, novel organic solvents, or electrolyte additives, has been ongoing. Because the additive can have great influence on the performance of the battery, the lithium ion battery can adapt to different working environments by adding some functional additives into the common electrolyte, and the working performance of the lithium ion battery is improved. Lithium battery electrolyte additives are of a wide variety, and almost every additive has one or more functions to improve the performance of a lithium battery. The research and development of the additives are the main content of the electrolyte research at present.
The performance of a lithium ion battery is influenced by the conduction rate of lithium ions in positive and negative electrode materials, the conduction rate of the lithium ions in an electrolyte, the crossing of the lithium ions on an electrode surface interface, the transfer rate of interface charges and the like.
The wettability of the electrolyte often refers to the wettability of the electrolyte and the non-polar polymer separator before. Some electrolytes with poor wettability are often selected from cyclic carbonates (PC, EC, GBL). Or some substances with a relatively high density such as sulfones, in particular some cyclic sulfones, such as sulfolane (TMS). For poor wettability, the original condition is often improved by adding some wettability substance. For example, some ionic or some nonionic surfactants or some small molecular weight aromatic and paraffinic hydrocarbons are very good wetting agents. Since the wettability of the electrolyte greatly affects the performance of the battery, much attention has been paid to a number of researchers.
However, the current requirements for electrolytes containing additives need to be met: (1) higher electricityConductivity, lithium ion migration number, proper viscosity and good wettability to diaphragms, electrodes and the like; (2) the chemical stability is good, namely the electrolyte, an electrode material, a diaphragm, an SEI film on the surface of an electrode and the like do not generate chemical reaction under the condition of placing or working; (3) to the positive electrode material (such as LiCoO)2，LiFePO4Etc.) has better oxidation resistance; (4) forming a stable solid electrolyte interface film on the surface of a negative electrode material such as graphite; (5) a purification film (such as FSC) can be formed on the surface of a positive current collector, aluminum foil and the like, but the current infiltration performance of the electrolyte is always a pain point in the electrolyte industry, and the defects of poor capacity exertion of positive and negative electrode materials, poor rate performance and the like caused by poor infiltration performance of the electrolyte always troubles the whole industry.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a novel lithium electrolyte for improving electrochemical properties such as specific capacity and cycling stability of a battery.
In one aspect, the present invention provides an electrolyte for a wettability-enhanced lithium ion battery, including: solvents, electrolytes and additives; the electrolyte is selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium dioxalate borate, N-dialkyl pyrrolidinium lithium salt, lithium difluorooxalate borate, lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide and lithium N-ethyl pyrrolidinium tetrafluoroborate;
the additive is a halogenated polyaromatic ring, and is preferably at least one selected from 1-chloronaphthalene, 1, 4-dichloronaphthalene, 1,2,3, 4-tetrachloronaphthalene, 1-bromonaphthalene, alpha-nitronaphthalene, 1-chloromethylnaphthalene, 1-iodonaphthalene, anthracene and 2-chloroanthracene.
In the disclosure, the inventor combines the development of the battery key materials and the identification of the process parameters such as the optimization of the anode and cathode interface films, and the like, and analyzes the materials together as an organic whole from local research to overall system research to finally obtain the high-performance lithium ion battery system with excellent performance. The inventor firstly finds that the halogenated aromatic ring additive can greatly improve the wettability of the electrolyte and the polymer diaphragm, and mainly bases on the fact that the halogenated aromatic ring has two advantages of electrophilicity and nucleophilicity. And a perfect SEI film can be formed on the interface, which is beneficial to the rapid exchange of lithium ions and the rapid conduction of electrons, and the electrode material and the electrolyte interface are connected with each other to solve the interface problem of the battery. Therefore, the performance and the service life of the lithium ion electrolyte are greatly improved when the lithium ion electrolyte has long-term cyclicity under high voltage and high temperature. The research result may provide certain basic data and theoretical basis for the industrial enterprises in the aspects of power battery improved battery design, material model selection, process parameter identification and the like.
Preferably, the molar ratio of the electrolyte to the additive is 1: (0.001 to 0.2), preferably 1: (0.005-0.2), more preferably 1: (0.05-0.08).
Preferably, the solvent is an organic solvent, preferably at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl acetate, methyl acetate, methylethyl carbonate, glutaronitrile, and tetrahydrofuran.
Preferably, the concentration of the electrolyte is 0.0001-5M, preferably 0.5-5M.
Preferably, the concentration of the additive is 0.005-0.2M, preferably 0.05-0.08M.
Preferably, when the electrolyte concentration in the electrolyte is 1M, the concentration of the additive is 0.005-0.2M.
In addition, when the electrolyte concentration in the electrolyte is 1M, the concentration of the additive is preferably 0.05-0.08M.
Preferably, the electrolyte of the wettability-enhanced lithium ion battery further comprises at least one of vinylene carbonate and fluorinated vinylene carbonate; the total volume of the vinylene carbonate and the fluorinated vinylene carbonate is 0.005-2% of the volume of the solvent.
In another aspect, the present invention further provides a lithium ion battery, including: the anode, the cathode and the wettability enhanced lithium ion battery electrolyte.
Has the advantages that:
according to the invention, a certain amount of halogenated polyaromatic ring is added into the lithium battery electrolyte as an additive, and the additive can effectively increase the infiltration degree of the electrolyte, a positive electrode material, a negative electrode material and a diaphragm, so that the electrolyte can be in effective contact with a larger degree more quickly. The conductivity and the electrochemical stability of the electrolyte are improved, so that the lithium battery can normally work in a harsher environment, the service life of the lithium battery can be prolonged, a higher electrochemical window can be provided, and the energy density and the power density are improved;
(2) the electrolyte can obviously improve the specific capacity of the battery, and shows higher coulombic efficiency and cycling stability. The median voltage of the cell can be significantly increased: 3.78V, and shows higher coulombic efficiency of 98 percent and cycle stability: the capacity of 600 cycles is maintained at 94%.
Drawings
FIG. 1 shows 1moL of lithium hexafluorophosphate (LiPF) used in example 16) A comparative graph showing the median voltage at different rates of discharge of a battery produced by adding 0.02M 1-chloronaphthalene to an electrolyte obtained by dissolving 1L of a solvent (EC: EMC: DMC 1:1:1+ 2% VC) and a battery not added with the 1-chloronaphthalene additive;
FIG. 2 shows 1moL of lithium hexafluorophosphate (LiPF) used in example 16) A comparative graph showing different rate discharge capacities of a battery prepared by adding 0.02M 1-chloronaphthalene to a 1L solvent (EC: EMC: DMC ═ 1:1:1+ 2% VC) and a battery not added with the 1-chloronaphthalene additive;
FIG. 3 shows 1moL of lithium hexafluorophosphate (LiPF) used in example 16) And a comparison graph of cycle life after charge and discharge tests of batteries prepared by dissolving 0.02M 1-chloronaphthalene in 1L of a solvent (EC: EMC: DMC ═ 1:1:1+ 2% VC) and batteries without 1-chloronaphthalene additive.
Detailed Description
The present invention is further illustrated by the following examples, which are to be understood as merely illustrative and not restrictive.
In the present disclosure, the composition of a lithium battery (lithium ion battery) electrolyte comprises: solvents, electrolytes and additives. Wherein the additive is a halogenated polyaromatic ring. The molar ratio of electrolyte to the additive may be 1: (0.001 to 0.2), preferably 1: (0.005-0.2).
Hereinafter, the electrolyte solution for a lithium ion battery according to the present invention will be schematically described by taking an electrolyte solution for a lithium ion battery of one embodiment as an example.
The lithium ion battery electrolyte of the invention contains a solvent. As the solvent, an organic solvent such as Ethylene Carbonate (EC), Propylene Carbonate (PC), butylene carbonate, dimethyl carbonate (DMC), diethyl carbonate, ethyl acetate, methyl acetate, Ethyl Methyl Carbonate (EMC), glutaronitrile, tetrahydrofuran, or the like, which may be one or a combination of several of them, may be used. The solvent is preferably Ethylene Carbonate (EC), Propylene Carbonate (PC), dimethyl carbonate (DMC) or diethyl carbonate, which is used in combination, due to the influence of conductivity and viscosity. In one example, EC is used: DMC 1:1 as solvent. Other additives described later may be added to the solvent. In another example, EC: EMC: DMC 1:1:1+ 2% VC was used as the solvent.
In an alternative embodiment, the organic solvent has a water content of 5ppm or less. The capacity fading caused by the excessive moisture content is prevented.
The lithium ion battery electrolyte of the present invention contains a lithium salt as an electrolyte. As the electrolyte, lithium hexafluorophosphate (LiPF) can be used6) Lithium tetrafluoroborate (LiBF)4) Lithium perchlorate, lithium bis (oxalato) borate (LiBOB), lithium N-dialkylpyrrolidinium salt, lithium difluoro (oxalato) borate (LiODFB), lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium N-ethylpyrrolidinium tetrafluoroborate, and the like. These lithium salts may be used alone, or 2 or more kinds may be used in combination. The lithium salt is preferably lithium hexafluorophosphate (LiPF) due to the effects of solubility and conductivity6) Lithium tetrafluoroborate (LiBF)4). Preferably, the water content of the electrolyte may be 5ppm or less. The capacity fading caused by the side reaction due to the excessive moisture content is prevented.
In an alternative embodiment, the concentration of the electrolyte in the electrolyte of the lithium ion battery can be 0.0001-5M. The concentration of the electrolyte is preferably 0.5 to 5M due to the influence of viscosity and conductivity.
The lithium ion battery electrolyte of the invention contains an additive. As the above-mentioned additive, halogenated aromatic rings such as 1-chloronaphthalene, 1, 4-dichloronaphthalene, 1,2,3, 4-tetrachloronaphthalene, 1-bromonaphthalene, α -nitronaphthalene, 1-chloromethylnaphthalene, 1-iodonaphthalene, anthracene, 2-chloroanthracene and the like can be used. The additive is preferably 1-chloronaphthalene due to the influence of molecular weight on viscosity and solubility limitation.
In the present invention, the best matching additive concentration is selected in combination with the requirements for coulombic efficiency and capacity. In the lithium ion battery electrolyte, the concentration of the additive can be 0.005-0.2M. When the electrolyte is used in a lithium ion battery, the capacity of the lithium battery increases with the increase of the concentration of an additive added within a certain range (0.005-0.2M), and the coulombic efficiency is reduced after the capacity exceeds the range. Since the migration speed of lithium ions is influenced by viscosity, the concentration of the additive is preferably 0.05 to 0.08M.
By taking 1-chloronaphthalene as an example, the inventor finds that a certain amount of 1-chloronaphthalene is added into the lithium battery electrolyte as an additive, and the additive can effectively increase the infiltration degree of the electrolyte, a positive electrode material, a negative electrode material and a diaphragm, so that the electrolyte can be in effective contact with the positive electrode material, the negative electrode material and the diaphragm more quickly and to a greater extent. The conductivity and the electrochemical stability of the electrolyte are improved, so that the lithium battery can normally work in a harsher environment, the service life of the lithium battery can be prolonged, a higher electrochemical window can be provided, and the energy density and the power density are improved. Therefore, the specific capacity of the battery can be obviously improved, and higher coulombic efficiency and cycling stability are shown. In addition, the surfactant is added into the electrolyte, so that the coordination adsorption of the anode and the cathode can be accelerated in the charging and discharging processes, the dissociation of the lithium ion solvent effect can be remarkably increased, the content and the power are increased along with the increase of the concentration of the added additive (such as 1-naphthalene chloride) in a certain range, and the energy density of the lithium ion battery is effectively improved by the modified electrolyte.
In alternative embodiments, the molar ratio of electrolyte to additive may be 1: (0.005-0.2), preferably 1: (0.0005 to 0.5), more preferably 1: (0.05-0.08). For example, when the electrolyte concentration in the electrolyte is 1M, the concentration of the additive is 0.005-0.2M, preferably 0.05-0.08M. The molar ratio of the electrolyte to the additive is 1: (0.005-0.2), the wettability is enhanced, and the advantages are complementary.
As an example, at least one of 1-chloronaphthalene, 1, 4-dichloronaphthalene, 1,2,3, 4-tetrachloronaphthalene, 1-bromonaphthalene, α -nitronaphthalene, 1-chloromethylnaphthalene, 1-iodonaphthalene, anthracene, 2-chloroanthracene, and the like, which are additives, may be added to a common electrolyte (e.g., an EC: EMC: DMC ═ 1:1:1+ 2% VC electrolyte, and the like).
In an alternative embodiment, the electrolyte may further include Vinylene Carbonate (VC), fluorinated vinylene carbonate (FEC), and other additives, so as to form a protective SEI film on the surface of the negative electrode. The volume of the other additive may be 0.005-0.2% of the volume of the solvent.
And (4) preparing an electrolyte. The preparation method comprises the following steps: the solute is injected into the mixed solution of the solvents, and the additives are added. The invention has simple process, easy control of the process and low preparation cost, and can be suitable for the field of electrolyte. Hereinafter, a method for producing the lithium ion battery electrolyte according to the present invention will be described as an example.
Firstly, weighing a certain amount of electrolyte, weighing an organic solvent (such as propylene carbonate) according to the required concentration, completely dissolving the electrolyte in the organic solvent, and uniformly stirring to obtain a clear transparent solution (mixed solution); and then, adding the additive into the mixed solution, and uniformly stirring to prepare the lithium battery electrolyte.
The electrolyte can be prepared in an oxygen-free, water-free and nitrogen-filled glove box, so that the conditions of abnormal failure of the battery and the like caused by high moisture and oxygen content in the air are reduced.
In one embodiment of the present invention, a lithium ion battery to which the electrolyte of the present invention is applied may include a positive electrode, a negative electrode, an electrolyte, and the like, and preferably may further include a separator. For example, the positive electrode may be lithium manganate, lithium nickelate, lithium iron phosphate, or the like. The negative electrode may be natural graphite, artificial graphite, hard carbon, or the like. The diaphragm can be a PP diaphragm, a PE diaphragm, an alumina fiber diaphragm and the like.
Taking a lithium battery button cell as an example, a positive electrode material, a conductive agent acetylene black and a binder polyvinylidene fluoride (PVDF) are fully stirred and uniformly mixed in an N-methyl pyrrolidone solvent system according to a mass ratio of (85-90%) (5-10%), and then coated on a positive electrode current collector Al foil for drying to obtain a positive electrode plate, wherein the positive electrode material of the lithium ion battery may include lithium cobaltate, lithium manganate, lithium iron phosphate and the like; the lithium battery button cell can be obtained by taking a PE porous polymeric film and the like as an isolating film, placing a diaphragm between a positive plate and a negative plate (lithium plate) and stacking the diaphragm in order, contacting one surface of the pole plate coated with an active material with the diaphragm, sealing the isolating film and the electrode plate by adopting a packaging shell, and filling prepared electrolyte.
The electrolyte is used in the lithium ion battery, and can obviously improve the specific capacity: 175mAh/g, and shows higher coulombic efficiency of 98 percent and circulation stability: the capacity is kept 89% after 1000 cycles.
The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below. In the following examples and comparative examples, the reagents, materials and instruments used were all commercially available as conventional reagents, conventional materials and conventional instruments unless otherwise specified, and the reagents involved therein were also synthesized by a conventional synthesis method.
Example 1
Preparing an electrolyte: 1moL of lithium hexafluorophosphate (LiPF)6) Dissolving in 1L of solvent (EC: EMC: DMC 1:1:1+ 2% VC), adding 1-chloronaphthalene in different concentrations (0.005M, 0.01M, 0.02M, 0.05M, 0.1M, 0.2M respectively), and stirring to obtain electrolyte;
preparing a lithium battery button battery: dissolving polyvinylidene fluoride (PVDF) with the mass percentage of 10 percent into N-2 methyl pyrrolidone (NMP), stirring until the PVDF is completely dissolved, then 80 percent by mass of anode material (lithium cobaltate) and 10 percent by mass of conductive acetylene black are poured into the slurry to be stirred, after 12 hours of high-speed stirring, the active material is completely dissolved, and the slurry is in a black colloid shape, 20 mu L of the slurry is uniformly coated on a current collector, then the coated electrode plate is flatly placed in a drying box, baking at 120 ℃ for 5min to completely volatilize the N-2 methyl pyrrolidone, placing a diaphragm between a pole piece and a lithium piece, stacking the pole piece and the lithium piece in order, contacting one surface of the pole piece coated with an active material with the diaphragm, sealing the isolating membrane and the electrode piece by adopting a packaging shell, and filling the prepared electrolyte to obtain the lithium battery button cell;
and (3) testing electrical properties: the resulting cell was measured for capacitance, specific capacitance, energy density and power density using constant current on the Shanghai Chenghua CHI660D electrochemical workstation. The voltage test range is 3.0V to 4.2V.
Comparative example 1
In a common electrolyte: 1moL of lithium hexafluorophosphate (LiPF)6) The lithium battery was assembled in the same manner as in example 1 by dissolving 1L of a solvent (EC: EMC: DMC ═ 1:1:1+ 2% VC).
The comparative graph test results of different-rate discharge median voltages of fig. 1 show that the battery of example 1 using the electrolyte prepared with the addition of 0.02M 1-chloronaphthalene additive has a higher median voltage of the corresponding lithium battery, compared to the lithium battery of the conventional commercial electrolyte of comparative example 1;
FIG. 2 is a graph comparing different-rate discharge capacities; the conventional electrolyte of comparative example 1 has a small rate of 5C capacity retention of 92%, while the electrolyte of example 1 using 0.02M 1-chloronaphthalene has a higher capacity retention of 96%. The capacity retention rate of the conventional electrolyte in comparative example 1 is 72% at a high rate of 65C, while the capacity retention rate of 84% in example 1 is higher when the electrolyte containing 0.02M 1-chloronaphthalene is used;
as can be seen from fig. 3, the discharge capacity of the electrolyte containing 0.02M 1-chloronaphthalene was more stable after the electrolyte containing 0.2M 1-chloronaphthalene was used in example 1, and the capacity retention rate was increased significantly and the efficiency was still maintained at about 94% compared to 90% after 600 weeks of the conventional electrolyte.
Example 2:
electrolyte solution: 1moL of lithium difluorooxalato borate (LiODFB) was dissolved in 1L (EC: EMC: DMC 1:1:1+ 2% VC), 1.4-dichloronaphthalene was added thereto at different concentrations (0M, 0.005M, 0.01M, 0.02M, 0.05M, 0.1M, and 0.2M, respectively), and the mixture was sufficiently stirred to prepare an electrolyte solution. The cell was prepared as in example 1. The electrical properties were tested as in example 1.
Example 3:
electrolyte solution: 1moL of lithium hexafluorophosphate (LiPF)6) Was dissolved in 1L (EC: EMC: DMC ═ 1:1:1+ 2% VC), and then 1,2,3, 4-tetrachloronaphthalene was added thereto at different concentrations (0M, 0.005M, 0.01M, 0.02M, 0.05M, 0.1M, and 0.2M, respectively), followed by sufficient stirring to prepare an electrolyte solution. The cell was prepared as in example 1. The electrical properties were tested as in example 1.
Example 4:
electrolyte solution: 1moL of lithium bis (fluorosulfonyl) imide (LiFSI) was dissolved in 1L of a solvent (EC: DMC 1:1), and 1-bromonaphthalene was added thereto at different concentrations (0M, 0.005M, 0.01M, 0.02M, 0.05M, 0.1M, and 0.2M, respectively), followed by sufficient stirring to prepare an electrolyte solution. The cell was prepared as in example 1. The electrical properties were tested as in example 1.
Example 5:
electrolyte solution: 1.5 molN-ethylpyrrolidinium lithium tetrafluoroborate was dissolved in 1L of a solvent (EC: DMC 1:1), and anthracene was added thereto at different concentrations (0M, 0.005M, 0.01M, 0.02M, 0.05M, 0.1M, and 0.2M, respectively), followed by sufficient stirring to prepare an electrolyte solution. The cell was prepared as in example 1. The electrical properties were tested as in example 1.
Table 1 shows the compositions and measured performance parameters of the electrolytes prepared in examples 1 to 5 of the present invention:
Figure BDA0002748185540000071
Figure BDA0002748185540000081
. From table 1, it can be seen that the addition of the additive can increase the capacity retention (%) at 5C of the battery, but the corresponding contents are substantially different for the different additives while improving the cycle performance: for example, when the additive is 1-chloronaphthalene, the cyclic performance can be improved when the concentration is 0.005-0.02M. The additive is 1.4-naphthalene dichloride, and when the concentration is 0.005-0.1M, the additive can also improve the cycle performance. The additive is 1,2,3, 4-naphthalene tetrachloride, and when the concentration is 0.01-0.2M, the additive can also improve the cycle performance. The additive is 1-naphthalene bromide, and when the concentration is 0.01-0.2M, the additive can also improve the cycle performance. The additive is anthracene, and the cycle performance is basically stable when the concentration is 0.005-0.2M.

Claims (9)

1. The electrolyte for the wettability-enhanced lithium ion battery is characterized by comprising the following components in percentage by weight: solvents, electrolytes and additives; the electrolyte is selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium dioxalate borate, N-dialkyl pyrrolidinium lithium salt, lithium difluorooxalate borate, lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide and lithium N-ethyl pyrrolidinium tetrafluoroborate;
the additive is a halogenated polyaromatic ring, and is preferably at least one selected from 1-chloronaphthalene, 1, 4-dichloronaphthalene, 1,2,3, 4-tetrachloronaphthalene, 1-bromonaphthalene, alpha-nitronaphthalene, 1-chloromethylnaphthalene, 1-iodonaphthalene, anthracene and 2-chloroanthracene.
2. The enhanced wettability lithium ion battery electrolyte of claim 1 wherein the molar ratio of said electrolyte to said additive is 1: (0.001 to 0.2), preferably 1: (0.005-0.2), more preferably 1: (0.05-0.08).
3. The improved wettability lithium ion battery electrolyte according to claim 1 or 2, wherein the solvent is an organic solvent, preferably at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl acetate, methyl acetate, methylethyl carbonate, glutaronitrile, and tetrahydrofuran.
4. The improved electrolyte solution for a lithium ion battery as claimed in any one of claims 1 to 3, wherein the concentration of the electrolyte is 0.0001-5M, preferably 0.5-5M.
5. The improved electrolyte for a lithium ion battery according to any one of claims 1 to 4, wherein the concentration of the additive is 0.005-0.2M, preferably 0.05-0.08M.
6. The electrolyte for the wettability-enhanced lithium ion battery according to claim 4 or 5, wherein the concentration of the additive is 0.005-0.2M when the electrolyte concentration in the electrolyte is 1M.
7. The electrolyte for the wettability-enhanced lithium ion battery of claim 6, wherein the concentration of the additive is 0.05-0.08M when the electrolyte concentration in the electrolyte is 1M.
8. The enhanced wettability lithium ion battery electrolyte of any one of claims 1-7, wherein said enhanced wettability lithium ion battery electrolyte further comprises at least one of vinylene carbonate and fluorinated vinylene carbonate; the total volume of the vinylene carbonate and the fluorinated vinylene carbonate is 0.005-2% of the volume of the solvent.
9. A lithium ion battery, comprising: a positive electrode, a negative electrode, and the wettability-enhanced lithium ion battery electrolyte of any one of claims 1-8.
CN202011174011.3A 2020-10-28 2020-10-28 Wettability-enhanced lithium ion battery electrolyte and application thereof Pending CN114421008A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1430306A (en) * 2001-12-28 2003-07-16 三井化学株式会社 Nonaqueous electrolyte and lithium secondary battery using the electrolyte
KR20110080324A (en) * 2010-01-05 2011-07-13 성균관대학교산학협력단 Electrolyte for lithium-ion battery and lithium-ion battery comprising the same
CN109888394A (en) * 2019-04-08 2019-06-14 黄杜斌 A kind of novel serondary lithium battery electrolyte

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1430306A (en) * 2001-12-28 2003-07-16 三井化学株式会社 Nonaqueous electrolyte and lithium secondary battery using the electrolyte
KR20110080324A (en) * 2010-01-05 2011-07-13 성균관대학교산학협력단 Electrolyte for lithium-ion battery and lithium-ion battery comprising the same
CN109888394A (en) * 2019-04-08 2019-06-14 黄杜斌 A kind of novel serondary lithium battery electrolyte

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