CN109786832B - Electrolyte additive, electrolyte and lithium ion secondary battery - Google Patents
Electrolyte additive, electrolyte and lithium ion secondary battery Download PDFInfo
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Abstract
The invention provides an electrolyte additive, an electrolyte and a lithium ion secondary battery. The electrolyte additive has the formula I
Having the structure shown in formula I, wherein R1，R2，R3Each independently being a hydrogen atom or a cyano group, R1，R2，R3At least one of which is cyano, R4，R5Each independently is an alkyl group of the formula CnH2n+1And n is 1 to 8. According to the invention, the additive is added into the electrolyte, so that the electrolyte can form an SEI film with high-temperature stability and cycle stability in the charging process. The reaction of the electrolyte on the surface of the electrode material can be effectively inhibited, the dissolution of the metal of the anode material is inhibited, the high-temperature cycle and storage performance of the lithium ion battery are improved, the gas generation during high-temperature storage is inhibited, and the comprehensive performance of the battery cell under high voltage is improved.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to an electrolyte additive, an electrolyte and a lithium ion secondary battery.
Background
The popularization of consumer electronics products, such as notebook computers, smart phones, wearable devices, unmanned aerial vehicles, and the like. The lithium ion battery is a green high-energy environment-friendly battery appearing in the nineties of the last century, and is widely applied to portable electronic products such as mobile phones, notebook computers, video cameras, digital cameras, tablet computers and the like with emphasis on lightness, thinness, shortness and multiple functions because of the advantages of high voltage, small volume, light weight, high specific energy, no memory effect, no pollution, small self-discharge, long service life and the like. But at the same time lithium ion secondary batteries need to have a higher capacity in a defined volume or a defined mass. Therefore, how to improve the energy density of the lithium ion battery and how to improve the safety performance of the battery under the condition of high energy density of the lithium ion battery are always difficult problems which need to be overcome for a long time. Under the present circumstances, increasing the cell operating voltage is one of the effective ways to increase the energy density, and the stability under high voltage, especially the stability of high temperature performance, is a great challenge.
Disclosure of Invention
In view of the problems mentioned in the background art, the present invention aims to provide an electrolyte additive, which is added to an electrolyte, and a lithium ion secondary battery prepared from the electrolyte has better high-temperature storage performance.
The inventor of the invention finds out in the research process that: in high temperature storage environments, the challenges facing the interior of the cell are: first, the high-temperature stability of the "solid electrolyte interface film" on the negative electrode: the decomposition of the SEI film at high temperature causes the decomposition reaction of the electrolyte on the negative electrode, so that a large amount of gas is generated in the battery cell and the storage electrochemical performance of the battery cell is affected. Secondly, the stability of the anode with high oxidation activity and the electrolyte at high temperature; the oxidative decomposition of the electrolyte by the positive electrode is enhanced under high voltage and high temperature conditions, and the reaction is the main cause of the large amount of gas generation of the battery cell. The two main reasons can cause the expansion deformation of the lithium ion secondary battery, and cause the short circuit inside the lithium ion secondary battery, or the combustible electrolyte leakage caused by the expansion and breakage of the battery package, thereby having the risk of causing safety accidents such as fire hazard.
In order to meet the requirements of long-term operation, high driving mileage, normal use in high and low temperature environments, rapid charging, and long service life of electric vehicles, it is necessary to develop a lithium ion secondary battery having higher energy density, more excellent high-temperature cycle, storage performance, and low-temperature rate performance.
In order to solve the above problems, and in view of the above needs, there is a need for an additive or a combination of additives that can enable the formation of a high temperature stable and cycle stable SEI film on the positive and negative electrodes of a lithium ion secondary battery. Thereby improving the comprehensive performance of the battery cell at high voltage.
The present invention provides an electrolyte additive, an electrolyte and a lithium ion secondary battery comprising the electrolyte. The additive provided by the invention can solve the problems of capacity attenuation and flatulence caused by long-term storage of the battery at room temperature or high temperature.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
according to a first aspect of the invention, there is provided a battery electrolyte additive having the structure of formula I;
wherein R is1，R2，R3Each independently is a hydrogen atom or a cyano group, and R1，R2，R3At least one of which is cyano, R4，R5Each independently is an alkyl group of the formula CnH2n+1And n is 1 to 8. The inventor realizes in the research process that the positive electrode used by the current commercial lithium ion power battery is mostly a ternary positive electrode material (LiNi) with high nickel content0.6Co0.2Mn0.2O2，LiNi0.8Co0.1Mn0.1O2) This positive electrode material has an unstable structure at high temperatures, and is easy to elute metal ions, and expensive Ni4+It is liable to undergo an oxidation reaction with the electrolyte, resulting in deterioration of the battery performance. The phosphorus-oxygen double bond in the aromatic phosphate compound provided by the invention has lone pair electrons, is Lewis base and can react on the surface of the anode material to form a layer of protective film, so that the high-temperature performance of the lithium ion battery is improved. In addition, cyano (-CN) in the aromatic phosphate compound provided by the invention can generate a complex reaction with metal ions, so that the activity of the metal ions is reduced, the side reaction in the battery is reduced, and the performance is improved. The electrolyte obtained by applying the electrolyte additive provided by the invention and the lithium ion secondary battery obtained by the electrolyte additive have the following properties: the high-temperature cycle and storage performance of the lithium ion battery are improved, and the high-temperature storage gas generation is inhibited, so that the high-temperature cycle and storage performance lithium ion battery is more suitable for the high-voltage requirement.
Further, said R4，R5Each independently selected from one of methane and ethane. The additives are added into the electrolyte, an SEI film with high temperature stability and stable circulation can be formed in the charging process, and the additives have the advantages of simple structure, simple preparation process and high yield.
Further, the additive is selected from at least one of the following compounds:
according to a second aspect of the invention, there is provided a battery electrolyte comprising: a non-aqueous organic solvent, a lithium salt dissolved in the non-aqueous organic solvent, and an additive dissolved in the non-aqueous organic solvent, the additive being as described in any embodiment of the first aspect of the invention.
Further, the mass of the additive accounts for 0.01-5% of the total mass of the nonaqueous organic solvent. When the content of the additive is too low, the protective effect on the electrode cannot be generated due to the too low content; when the content of the additive is too high, the viscosity of the electrolyte increases, thereby deteriorating the cycle performance of the lithium ion secondary battery. When the mass ratio of the additive to the total mass of the nonaqueous organic solvent is 0.01-5%, the normal-temperature and high-temperature cycle storage performance of the lithium ion secondary battery can be improved. For example, the concentration may be 0.05 to 5%, 0.1 to 5%, 1 to 4%, or the like, and any range value of these ranges.
Further, the mass of the additive accounts for 0.5-3% of the total mass of the nonaqueous organic solvent. When the mass of the additive accounts for 0.5-3% of the total mass of the non-aqueous organic solvent, the normal-temperature and high-temperature cycle storage performance of the lithium ion battery can be remarkably improved, and the protection effect on the electrode is exerted.
Further, the non-aqueous organic solvent comprises cyclic carbonate and chain carbonate, wherein the cyclic carbonate is at least one selected from ethylene carbonate, propylene carbonate and gamma-butyrolactone; the chain carbonate is at least one selected from dimethyl carbonate, butylene carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate. The cyclic carbonate and chain carbonate are used as solvents for lithium ion batteries, and have the advantages of good oxidation reduction resistance, high dielectric constant and low viscosity.
Further, the lithium salt is selected from LiPF6 and LiBF4、LiBOB、LiDFOB、LiAsF6、Li(CF3SO2)2N、Li(FSO2)2N、LiPO2F2、LiCF3SO3、LiClO4At least one of (1). These lithium salts have the advantages of high conductivity, good thermal stability and good electrochemical stability. The preparation method is applied to the preparation process of the battery electrolyte, and can enhance the conductivity and electrochemical stability of the battery electrolyte.
According to a third aspect of the present invention, there is provided a lithium ion secondary battery comprising: the positive plate comprises a positive current collector and a positive membrane containing a positive active material, which is arranged on the positive current collector; the negative plate comprises a negative current collector and a negative diaphragm containing a negative active material, which is arranged on the negative current collector; the spacing film is arranged between the positive plate and the negative plate; an electrolyte according to any embodiment of the second aspect of the present invention.
Further, the positive active material is selected from transition metal oxides of lithium.
Further, the transition metal oxide of lithium is selected from LiCoO2、LiMn2O4、LiMnO2、Li2MnO4、LiFePO4、LiNixCoyMnzO2、Li1+aMn1-xMxO2、LiCo1-xMxO2、LiFe1-xMxPO4、LiMn2-yMyO4、Li2Mn1-xO4Wherein M is at least one selected from Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F and Y, and a is more than or equal to 0<0.2, x is more than or equal to 0, y and z are less than or equal to 1. The material is used as the anode active material and has high energy density and cyclicityGood performance and the like.
Further, the negative active material is selected from at least one of natural graphite, artificial graphite, soft carbon, hard carbon, lithium titanate, silicon-carbon alloy and silicon-oxygen alloy. These materials are likely to undergo lithium ion intercalation and deintercalation reactions and can be used as a preferable negative electrode active material.
Detailed Description
The following detailed description of embodiments of the invention is intended to be illustrative of the invention and is not to be construed as limiting the invention.
According to one aspect of the present invention, there is provided an electrolyte additive having the formula I:
wherein R is1，R2，R3Each independently is a hydrogen atom or a cyano group, and R1，R2，R3At least one of which is cyano, R4，R5Each independently is an alkyl group of the formula CnH2n+1，n＝1～8。
The phosphorus-oxygen double bond in the cyano-substituted aromatic phosphate compound shown in the formula I has lone pair electrons, and the cyano-substituted aromatic phosphate compound can react on the surface of a positive electrode material to form a protective film when applied to an electrolyte, so that the high-temperature performance of a battery is improved. And cyano (-CN) in the compound can be complexed with metal ions, so that the activity of the metal ions is reduced, and side reactions in the battery are reduced. The compound is used as the additive of the battery electrolyte, and the performance of the battery can be obviously improved.
In some preferred embodiments, the additive may comprise at least one of the following compounds:
in some embodiments, the additives may be prepared by reference to the synthesis of the structurally similar common pesticide thiocyanoton (Cyanophos). For example, taking compound 1 as an example, the synthesis method of compound 1 is as follows: 4-cyanophenol and O, O-dimethylphosphoryl chloride are stirred at room temperature for 8 hours under the catalysis of a base (such as anhydrous potassium carbonate or triethylamine) by using acetonitrile as a solvent, and the product is obtained after filtration and drying under reduced pressure. The reaction equation is as follows:
similarly, in the preparation of compound 2, 3, 4-dicyanophenol and O, O-dimethylphosphoryl chloride are stirred at room temperature for 10 hours under the catalysis of a base (e.g., anhydrous potassium carbonate or triethylamine) using acetonitrile as a solvent, filtered and dried under reduced pressure to give compound 2. Similarly, other additives may be prepared with reference to the above methods. For example, methyl phosphoryl chloride and cyanophenol are reacted under the catalysis of a base by using acetonitrile as a solvent, and the corresponding compound is obtained after filtration and drying under reduced pressure. The obtained compound was confirmed by nuclear magnetic resonance detection.
When the additive is used for preparing the battery electrolyte, the content of the additive in the electrolyte is not easy to be too high or too low. In some embodiments, the additive is present in an amount of 0.01% to 5% by weight of the total mass of the electrolyte of the lithium ion secondary battery.
The invention also provides an electrolyte of the lithium ion secondary battery, which comprises a non-aqueous organic solvent, a lithium salt and the additive.
In some embodiments of the present invention, the non-aqueous organic solvent comprises a cyclic carbonate and a chain carbonate. The cyclic carbonate is selected from one or more of ethylene carbonate, propylene carbonate and gamma-butyrolactone; the chain carbonate is selected from one or more of dimethyl carbonate, butylene carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate.
In still other embodiments of the present invention, the lithium salt is selected from LiPF6、LiBF4、LiBOB、LiDFOB、LiAsF6、Li(CF3SO2)2N、Li(FSO2)2N、LiPO2F2、LiCF3SO3、LiClO4One or more of them.
The present invention also provides a lithium ion secondary battery comprising: the positive plate comprises a positive current collector and a positive membrane containing a positive active material, which is arranged on the positive current collector; the negative plate comprises a negative current collector and a negative diaphragm containing a negative active material, which is arranged on the negative current collector; the spacing film is arranged between the positive plate and the negative plate; and the electrolyte. Of course, the lithium ion secondary battery is also provided with a package outside according to the general understanding of the art, and may be, for example, an aluminum plastic film, a stainless steel cylinder, a square aluminum case, or the like.
In some embodiments, the positive active material is selected from transition metal oxides of lithium, wherein the transition metal oxide of lithium is LiCoO2、LiMn2O4、LiMnO2、Li2MnO4、LiFePO4、LiNixCoyMnzO2、Li1+aMn1-xMxO2、LiCo1-xMxO2、LiFe1-xMxPO4、LiMn2-yMyO4、Li2Mn1-xO4Wherein M is one or more selected from Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F and Y, and a is more than or equal to 0<0.2，0≤x,y,z≤1。
In some embodiments, the negative active material includes, but is not limited to, one or more of natural graphite, artificial graphite, soft carbon, hard carbon, lithium titanate, silicon carbon alloy, silicon oxygen alloy, and the like, which are capable of undergoing a lithium ion intercalation and deintercalation reaction.
In at least some embodiments, the lithium ion secondary battery provided by the present invention has a cutoff voltage of 4.1v to 4.8 v. In at least some embodiments, the lithium ion secondary battery provided by the invention has a capacity retention rate of 85% or more after 500 charge-discharge cycles. In at least some embodiments, the lithium ion secondary battery provided by the invention has a storage capacity retention rate of 85% or more when stored at 60 degrees celsius for 30 days. In at least other embodiments, the lithium ion secondary battery provided by the present invention has a core volume expansion rate of 30% or less when stored at 60 degrees celsius for 30 days. Thus, a lithium ion secondary battery having excellent performance in all aspects, particularly, having improved high-temperature cycle and storage performance and maintaining excellent performance at high voltage can be provided.
The embodiment of the present invention will be specifically described below by way of specific examples. It should be noted that the following examples are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
Example 1
(1) Preparation of positive plate of lithium ion secondary battery
Preparing positive electrode active material nickel cobalt lithium manganate (LiNi)0.6Co0.2Mn0.2O2) Dissolving a conductive agent Super-P and a bonding agent PVDF in a solvent N-methyl pyrrolidone according to a mass ratio of 96:2.0:2.0, uniformly mixing to prepare anode slurry, and uniformly coating the anode slurry on a current collector aluminum foil with a coating amount of 18mg/cm2And then drying at 85 ℃, performing cold pressing, trimming, cutting into pieces and slitting, drying for 4 hours at 85 ℃ under a vacuum condition, and welding tabs to prepare the positive plate of the lithium ion secondary battery meeting the requirements.
(2) Preparation of negative plate of lithium ion secondary battery
Activating the negative electrodeDissolving artificial graphite, a conductive agent Super-P, a thickening agent CMC and a binding agent SBR in a solvent deionized water according to a mass ratio of 96.5:1.0:1.0:1.5, uniformly mixing to prepare a negative electrode slurry, and then uniformly coating the negative electrode slurry on a current collector copper foil with a coating amount of 8.9mg/cm2And then drying at 85 ℃, performing cold pressing, trimming, cutting into pieces and slitting, drying for 4 hours at 110 ℃ under a vacuum condition, and welding tabs to prepare the negative plate of the lithium ion secondary battery meeting the requirements.
(3) Preparation of electrolyte for lithium ion secondary battery
LiPF serving as electrolyte of lithium ion secondary battery6The electrolyte is a lithium salt (the concentration of the potassium salt in the electrolyte is 1mol/L), a mixture of Ethylene Carbonate (EC), Ethyl Methyl Carbonate (EMC) and diethyl carbonate (DEC) is used as a non-aqueous organic solvent, and the mass ratio of EC to EMC to DEC is 30:50: 20. In addition, the electrolyte of the lithium ion secondary battery also contains an additive, wherein the additive is the compound 1 accounting for 0.5 percent of the total mass of the electrolyte of the lithium ion secondary battery.
(4) Preparation of lithium ion secondary battery
And (2) manufacturing the positive plate, the negative plate and the isolating membrane (PE membrane) of the lithium ion secondary battery prepared according to the process into a battery cell with the thickness of 8mm, the width of 60mm and the length of 130mm through a winding process, baking the battery cell in vacuum at 75 ℃ for 10h, injecting electrolyte, standing for 24h, then charging the battery cell to 4.2V by using a constant current of 0.1C (160mA), then charging the battery cell to 0.05C (80mA) by using a constant voltage of 4.2V until the current is reduced to 0.05C (160mA), then discharging the battery cell to 2.8V by using a constant current of 0.1C (160mA), repeating the charging and discharging for 2 times, and finally charging the battery cell to 3.8V by using a constant current of 0.1C (160mA) to finish the preparation of the lithium ion secondary battery.
Example 2
A lithium ion secondary battery was prepared in accordance with the method of example 1, except that in the preparation of the electrolyte of the lithium ion secondary battery (i.e., step (3)), the amount of the additive compound 1 was 1% by mass of the total mass of the electrolyte.
Example 3
A lithium ion secondary battery was prepared in accordance with the method of example 1, except that in the preparation of the electrolyte of the lithium ion secondary battery (i.e., step (3)), the amount of the additive compound 1 was 2% by mass of the total mass of the electrolyte.
Example 4
A lithium ion secondary battery was prepared in accordance with the method of example 1, except that in the preparation of the electrolyte of the lithium ion secondary battery (i.e., step (3)), the amount of the additive compound 1 was 3% of the total mass of the electrolyte.
Example 5
A lithium ion secondary battery was produced in accordance with the method of example 1, except that in the production of the electrolyte for a lithium ion secondary battery (i.e., step (3)), the additive was compound 2, and the amount of the compound was 1% by mass of the total mass of the electrolyte.
Comparative example 1
A lithium ion secondary battery was manufactured according to the method of example 1, except that: except that no additive was added in the preparation of the electrolyte solution for a lithium ion secondary battery (i.e., step (3)).
Comparative example 2
A lithium ion secondary battery was manufactured according to the method of example 1, except that: except that in the preparation of the electrolyte for a lithium ion secondary battery (i.e., step (3)), the amount of the additive compound 1 was 0.001% of the total mass of the electrolyte.
Comparative example 3
A lithium ion secondary battery was manufactured according to the method of example 1, except that: except that in the preparation of the electrolyte for a lithium ion secondary battery (i.e., step (3)), the amount of the additive compound 1 was 8% by mass of the total mass of the electrolyte.
Then, the performance of the lithium ion secondary batteries prepared in examples 1 to 5 and comparative examples 1 to 3 was tested according to the following methods, respectively.
1. High temperature cycle performance test of lithium ion secondary battery
The high-temperature cycle performance of the lithium ion secondary batteries prepared in examples 1 to 4 and the lithium ion secondary batteries prepared in comparative examples 1 to 3 was tested, specifically: at 60 ℃, the lithium ion secondary battery is charged to 4.2V by constant current of 1C, then charged to current of 0.05C by constant voltage of 4.2V, and then discharged to 2.8V by constant current of 1C, which is a charge-discharge cycle process, and the discharge capacity of the time is the discharge capacity of the first cycle. The lithium ion secondary battery was subjected to a cyclic charge-discharge test in the above manner, and the discharge capacity at the 500 th cycle was taken.
The capacity retention (%) after 500 cycles of the lithium ion secondary battery was [ discharge capacity at 500 cycles/discharge capacity at first cycle ] × 100%.
The test results of the batteries are shown in table 1.
2. High temperature storage performance test of lithium ion secondary battery
At 25 ℃, charging the lithium ion secondary battery to 4.2V at a constant current of 1C, further charging the lithium ion secondary battery to a constant voltage of 4.2V until the current is 0.05C, and then discharging the lithium ion secondary battery to 2.8V at a constant current of 1C, wherein the discharge capacity at this time is the discharge capacity of the lithium ion secondary battery before high-temperature storage; and then charging the lithium ion secondary battery to 4.2V by using a constant current of 1C, storing the lithium ion secondary battery at 60 ℃ for 30 days, after the storage is finished, placing the lithium ion secondary battery in an environment of 25 ℃, then discharging the lithium ion secondary battery to 2.8V by using a constant current of 0.5C, then charging the lithium ion secondary battery to 4.2V by using a constant current of 1C, further charging to 1C by using a constant voltage of 4.2V, then discharging the lithium ion secondary battery to 2.8V by using a constant current of 1C, and finally, the discharge capacity of the last time is the discharge capacity of the lithium ion secondary battery after high-temperature storage. Capacity retention (%) after high-temperature storage of the lithium ion secondary battery [ discharge capacity after high-temperature storage of the lithium ion secondary battery/discharge capacity before high-temperature storage of the lithium ion secondary battery ] × 100%.
3. High-temperature storage gas production performance test of lithium ion secondary battery
At 25 ℃, charging the lithium ion secondary battery to 4.2V at a constant current of 1C, further charging the lithium ion secondary battery to a constant voltage of 4.2V until the current is 0.05C, and then discharging the lithium ion secondary battery to 2.8V at a constant current of 1C, wherein the discharge capacity at this time is the discharge capacity of the lithium ion secondary battery before high-temperature storage; then, the lithium ion secondary battery was charged to 4.2V at a constant current of 1C, charged at a constant voltage of 4.2V to a current of 0.05C, and fully charged. The volume of the battery cell is tested by adopting a drainage method, and the thickness of the battery cell is measured by using a micrometer.
And then storing the lithium ion battery at 60 ℃ for 30 days, after the storage is finished, placing the lithium ion secondary battery in an environment of 25 ℃, testing the volume of the battery cell by adopting a drainage method, and measuring the thickness of the battery cell by using a micrometer. Then the lithium ion secondary battery is discharged to 2.8V with a constant current of 0.5C, then the lithium ion secondary battery is charged to 4.2V with a constant current of 1C, further the lithium ion secondary battery is charged to a constant voltage of 4.2V until the current is 1C, then the lithium ion secondary battery is discharged to 2.8V with a constant current of 1C, and the last discharge capacity is the discharge capacity of the lithium ion secondary battery after high-temperature storage.
Cell volume expansion rate (volume after storage/volume before storage-1)%
TABLE 1 parameters and Performance test results for examples 1-5 and comparative examples 1-3
From the results shown in table 1, comparing the results of examples 1 to 5 and comparative example 1, compared with the battery without any additive, with the addition of the phosphate compound 1, the capacity retention rate of the lithium ion secondary battery after being stored at 60 ℃ for 30 days is increased, the capacity retention rate after being cycled at 60 ℃ is also increased, and the capacity retention rate after being stored at high temperature is decreased, which indicates that the phosphate compound may inhibit the side reaction of the electrolyte and the cathode material at high temperature, thereby increasing the capacity retention rate of the battery after being stored at high temperature and cycled.
It can be seen from comparative examples 2 and 3 that when the content of the phosphate ester additive is too low (0.001%), it does not play a role in protecting the positive electrode, and when the content of the phosphate ester additive is too high (8%), it is possible that the viscosity of the electrolyte increases due to too high content, deteriorating the cycle performance of the battery.
It should be noted that, although only additive compound 1 and compound 2 are exemplified in the examples of the present specification, according to other embodiments of the lithium ion secondary battery of the present invention, the additive for the electrolyte of the lithium ion secondary battery may be one or more of the additive compounds mentioned in other claims.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
While embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and not to be construed as limiting of the present invention, as will be apparent to those of ordinary skill in the art. Variations and modifications to the above-described embodiments may also occur to those skilled in the art from the disclosure and description of the above specification. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (8)
1. An electrolyte, comprising:
a non-aqueous organic solvent, and a solvent,
a lithium salt dissolved in the non-aqueous organic solvent,
and an additive dissolved in the non-aqueous organic solvent, the additive being selected from at least one of the following compounds:
the mass of the additive accounts for 0.01-5% of the total mass of the nonaqueous organic solvent.
2. The electrolyte of claim 1, wherein the additive is present in an amount of 0.5% to 3% by mass based on the total mass of the nonaqueous organic solvent.
3. The electrolyte solution according to claim 1, wherein the non-aqueous organic solvent contains a cyclic carbonate and a chain carbonate,
the cyclic carbonate is selected from at least one of ethylene carbonate, propylene carbonate and gamma-butyrolactone;
the chain carbonate is at least one selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate.
4. The electrolyte of claim 1, wherein the lithium salt is selected from LiPF6、LiBF4、LiBOB、LiDFOB、LiAsF6、Li(CF3SO2)2N、Li(FSO2)2N、LiPO2F2、LiCF3SO3、LiClO4At least one of (1).
5. A lithium-ion secondary battery characterized by comprising:
the positive plate comprises a positive current collector and a positive membrane containing a positive active material, which is arranged on the positive current collector;
the negative plate comprises a negative current collector and a negative diaphragm containing a negative active material, which is arranged on the negative current collector;
the spacing film is arranged between the positive plate and the negative plate;
an electrolyte according to any one of claims 1 to 4.
6. The lithium ion secondary battery according to claim 5, wherein the positive electrode active material is selected from transition metal oxides of lithium.
7. The lithium ion secondary battery according to claim 6, wherein the transition metal oxide of lithium is selected from LiCoO2、LiMn2O4、LiMnO2、Li2MnO4、LiFePO4、LiNixCoyMnzO2、Li1+aMn1-xMxO2、Li Co1-xMxO2、LiFe1-xMxPO4、LiMn2-yMyO4、Li2Mn1-xO4Wherein M is at least one selected from Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F and Y, and a is more than or equal to 0<0.2，0≤x,y,z≤1。
8. The lithium ion secondary battery according to claim 5, wherein the negative active material is selected from at least one of natural graphite, artificial graphite, soft carbon, hard carbon, lithium titanate, silicon carbon alloy, and silicon oxygen alloy.
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| CN111509232B (en) * | 2020-05-29 | 2022-10-25 | 蜂巢能源科技有限公司 | Positive plate and preparation method and application thereof |
| CN114122513B (en) * | 2020-08-28 | 2024-06-18 | 天津中电新能源研究院有限公司 | Functional electrolyte additive, battery electrolyte and sodium ion battery |
| CN113471538B (en) * | 2021-08-18 | 2022-12-06 | 中节能万润股份有限公司 | Lithium ion battery nonaqueous electrolyte additive and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102414902A (en) * | 2009-04-22 | 2012-04-11 | 中央硝子株式会社 | Electrolyte for electrochemical device, electrolyte solution using same, and nonaqueous electrolyte battery |
| EP2796926A2 (en) * | 2013-04-25 | 2014-10-29 | Samsung SDI Co., Ltd. | Additive for an electrolyte for a lithium battery, organic electrolytic solution comprising the same, and lithium battery comprising the organic electrolytic solution |
| JP2016139611A (en) * | 2015-01-23 | 2016-08-04 | 東ソ−・エフテック株式会社 | Nonaqueous electrolyte and nonaqueous secondary battery using the same |
| CN106486696A (en) * | 2015-08-31 | 2017-03-08 | 比亚迪股份有限公司 | A kind of non-aqueous electrolyte for lithium ion cell and lithium ion battery |
| CN106558731A (en) * | 2015-09-28 | 2017-04-05 | 比亚迪股份有限公司 | A kind of lithium-ion battery electrolytes and lithium ion battery |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6919141B2 (en) * | 1998-10-22 | 2005-07-19 | Wilson Greatbatch Technologies, Inc. | Phosphate additives for nonaqueous electrolyte rechargeable electrochemical cells |
| CN102918701B (en) * | 2010-05-25 | 2017-05-03 | U芝加哥阿尔贡股份有限公司 | Polyether-functionalized redox shuttle additives for lithium ion batteries |
-
2019
- 2019-01-09 CN CN201910020535.8A patent/CN109786832B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102414902A (en) * | 2009-04-22 | 2012-04-11 | 中央硝子株式会社 | Electrolyte for electrochemical device, electrolyte solution using same, and nonaqueous electrolyte battery |
| EP2796926A2 (en) * | 2013-04-25 | 2014-10-29 | Samsung SDI Co., Ltd. | Additive for an electrolyte for a lithium battery, organic electrolytic solution comprising the same, and lithium battery comprising the organic electrolytic solution |
| JP2016139611A (en) * | 2015-01-23 | 2016-08-04 | 東ソ−・エフテック株式会社 | Nonaqueous electrolyte and nonaqueous secondary battery using the same |
| CN106486696A (en) * | 2015-08-31 | 2017-03-08 | 比亚迪股份有限公司 | A kind of non-aqueous electrolyte for lithium ion cell and lithium ion battery |
| CN106558731A (en) * | 2015-09-28 | 2017-04-05 | 比亚迪股份有限公司 | A kind of lithium-ion battery electrolytes and lithium ion battery |
Non-Patent Citations (1)
| Title |
|---|
| 亚磷酸三苯酯作为锂离子电池电解液稳定剂的研究;王超等;《材料导报》;20110525;第25卷;第294-296页 * |
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