CN110611123A - Lithium ion battery electrolyte and lithium ion battery - Google Patents
Lithium ion battery electrolyte and lithium ion battery Download PDFInfo
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- CN110611123A CN110611123A CN201911013607.2A CN201911013607A CN110611123A CN 110611123 A CN110611123 A CN 110611123A CN 201911013607 A CN201911013607 A CN 201911013607A CN 110611123 A CN110611123 A CN 110611123A
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- H—ELECTRICITY
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- 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
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- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—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
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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 a lithium ion battery electrolyte and a lithium ion battery. The lithium ion battery electrolyte comprises an organic solvent and a lithium salt, wherein the lithium salt comprises Li2B12(CN)12And/or Li2CB11(CN)12. The invention adopts the novel lithium salt to partially or completely replace halogen-containing salt (such as lithium hexafluorophosphate), thereby effectively reducing the toxicity of the prior halogen-containing salt electrolyte. The novel lithium salt is added into the electrolyte of the battery, so that the high-voltage resistance of the battery is improved, and the obtained lithium ion battery can be used at high voltage of 4.45V or above; meanwhile, the high-temperature storage performance of the battery in a full-charge state can be improved, the cycle life of the battery at 45 ℃ can be prolonged, the safety of the battery is further improved, and the low-temperature performance of the battery cannot be influenced.
Description
Technical Field
The invention belongs to the technical field of battery materials, and particularly relates to a lithium ion battery electrolyte and a lithium ion battery.
Background
With the continuous improvement of the energy density requirement of the lithium ion battery, the charge cut-off voltage of the lithium ion battery is also improved, and the defects that the full-charge high-temperature storage performance is reduced, the high-temperature cycle life is quickly attenuated and the like generally exist in the high-voltage lithium ion battery with the voltage of 4.45V or more in the current market compared with the lithium ion battery with the voltage of less than 4.45V. Therefore, there is a need to develop a new lithium salt to improve the voltage resistance, long cycle life, and safety of the battery, thereby overcoming the LiPF6The defects of easy reaction, no high temperature resistance and the like exist.
At present, to overcome LiPF6The electrolyte is insufficient, and lithium salt supplement LiFSI, LiTFSI, LiBOB, LiODFB and LiAsF are usually selected and used in the prior art6、Li(SO2CF3)2And LiClO4Etc. as disclosed in CN103531845A by LiBF2SO4The lithium ion battery electrolyte based on lithium salt comprises electrolyte lithium salt and aprotic solvent, wherein the electrolyte lithium salt can be single LiBF2SO4Or may be LiBF2SO4And other common lithium salts. CN105470575B discloses a wide temperature range electrolyte, which comprises a liquid electrolyte, wherein the liquid electrolyte comprises an electrolyte lithium salt and a non-aqueous organic solvent, the electrolyte lithium salt is composed of an A-class lithium salt and a B-class lithium salt, and the A-class lithium salt is selected from one of lithium trifluoroacetate, lithium fluoroalkyl phosphate, lithium bis (trifluoromethylsulfonic acid) imide, lithium bis (fluorosulfonyl) imide and lithium tetrafluoroborateThe B-type lithium salt is selected from one of lithium hexafluorophosphate, lithium dioxalate borate and lithium difluorooxalate borate. However, the above lithium salts all have drawbacks at high voltages, such as: high pressure difference resistance, high and low temperature performance, high toxicity, poor safety, easy explosion and the like.
Therefore, there is a need to find or develop a new lithium salt to supplement or replace LiPF6And the battery performance requirement under high voltage is met.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a lithium ion battery electrolyte and a lithium ion battery. The lithium ion battery electrolyte disclosed by the invention is beneficial to forming a stable protective film on a positive electrode and a negative electrode in a high-voltage lithium ion battery with the voltage of 4.45V or above, can improve the high-voltage resistance of the lithium ion battery, prolong the long cycle life, improve the high-temperature resistance and safety of the battery, and does not influence the low-temperature performance of the battery.
One of the objects of the present invention is to provide a lithium ion battery electrolyte comprising an organic solvent and a lithium salt, wherein the lithium salt comprises Li2B12(CN)12And/or Li2CB11(CN)12。
The present invention provides a novel lithium salt comprising Li2B12(CN)12And/or Li2CB11(CN)12The novel lithium salt is adopted to partially or completely replace halogen-containing salt (such as lithium hexafluorophosphate), so that the toxicity of the existing halogen-containing salt electrolyte can be effectively reduced. The novel lithium salt is added into the electrolyte of the battery, so that the high-voltage resistance of the battery is improved, and the obtained lithium ion battery can be used at high voltage of 4.45V or above; meanwhile, the high-temperature storage performance of the battery in a full-charge state can be improved, the cycle life of the battery at 45 ℃ can be prolonged, the safety of the battery is further improved, and the low-temperature performance of the battery cannot be influenced.
FIG. 1 shows Li in the present invention2B12(CN)12FIG. 2 is a molecular structure model of Li in the present invention2CB11(CN)12A molecular structure model of (1).
Preferably, the lithium salt further includes lithium hexafluorophosphate, or a mixed salt of lithium hexafluorophosphate and a doped lithium salt.
Preferably, the doped lithium salt comprises Li2CB11H12、Li2B12H12、LiBH4、LiB3H8Any one or a combination of at least two of lithium difluorooxalate phosphate and lithium tetrafluorooxalate phosphate.
The lithium salt in the present invention is preferably Li2B12(CN)12And/or Li2CB11(CN)12And a mixed salt obtained by mixing lithium hexafluorophosphate with a doped lithium salt.
Preferably, in the lithium ion battery electrolyte, Li2B12(CN)12The mass concentration percentage of (B) is 0.1 wt% to 20.0 wt%, for example, 0.5 wt%, 1.0 wt%, 2.0 wt%, 5.0 wt%, 8.0 wt%, 10.0 wt%, 12.0 wt%, 15.0 wt%, 18.0 wt%, or 20.0 wt%.
Preferably, in the lithium ion battery electrolyte, Li2CB11(CN)12The mass concentration percentage of (B) is 0.1 wt% to 20 wt%, for example, 0.5 wt%, 1.0 wt%, 2.0 wt%, 5.0 wt%, 8.0 wt%, 10.0 wt%, 12.0 wt%, 15.0 wt%, 18.0 wt%, or 20.0 wt%.
Preferably, the lithium salt includes Li2CB11(CN)12And Li2B12(CN)12In the lithium ion battery electrolyte, Li2CB11(CN)12And Li2B12(CN)12Is 0.1 wt% to 20.0 wt%, such as 0.5 wt%, 1.0 wt%, 2.0 wt%, 5.0 wt%, 8.0 wt%, 10.0 wt%, 12.0 wt%, 15.0 wt%, 18.0 wt%, or 20.0 wt%.
Preferably, the lithium salt is present in the lithium ion battery electrolyte in a total concentration percentage by mass of 10.0 wt% to 20.0 wt%, such as 11.0 wt%, 12.0 wt%, 13.0 wt%, 14.0 wt%, 15.0 wt%, 16.0 wt%, 17.0 wt%, 18.0 wt%, 19.0 wt%, or the like.
Preferably, the amount of the organic solvent added in the lithium ion battery electrolyte is 57-85 wt%, such as 58 wt%, 60 wt%, 62 wt%, 64 wt%, 65 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 76 wt%, 78 wt%, 80 wt%, 82 wt% or 84 wt% of the total mass of the lithium ion battery electrolyte.
Preferably, the organic solvent comprises ethylene carbonate and/or propylene carbonate.
Preferably, the organic solvent further comprises any one or a combination of at least two of diethyl carbonate, ethyl methyl carbonate, propyl propionate, ethyl propionate, propyl acetate, butyl butyrate, and ethyl butyrate.
Preferably, the lithium ion battery electrolyte further comprises an additive.
Preferably, the additive comprises vinylene carbonate, 1, 3-propane sultone, fluoroethylene carbonate, ethylene carbonate, 1, 3-propylene sultone, 1, 4-butane sultone, pentafluoroalkylcyclotriphosphazene, triallyl isocyanurate, ethyl 4,4, 4-trifluorobutyrate, 1,2, 2-tetrafluoroethyl-2, 2,3, 3-tetrafluoropropyl ether, any one or a combination of at least two of ethylene glycol dipropionitrile ether, 1,3, 6-hexanetricarbonitrile, adiponitrile, succinonitrile, citric anhydride, fluorobenzene, boron trifluoride tetrahydrofuran, tris (trimethylsilane) phosphate, tris (trimethylsilane) borate and methylene methanedisulfonate, preferably any one or a combination of at least two of vinylene carbonate, 1, 3-propanesultone and fluoroethylene carbonate.
Preferably, the content of the additive in the lithium ion battery electrolyte is 5-15 wt%, such as 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt% or 14 wt%.
The second purpose of the present invention is to provide a lithium ion battery comprising the lithium ion battery electrolyte according to the first purpose.
Preferably, the lithium ion battery further comprises a positive electrode, a negative electrode and a separator.
Preferably, the active material in the positive electrode: conductive agent: the binder is (90-98): (1-5), such as 90:5:5, 92:4:4, 93:4:3, 93:3:4, 94:3:3, 95:2.5:2.5, 97:1.5:1.5, 97:2:1 or 98:1: 1.
Preferably, the conductive agent is conductive carbon black Super-P.
Preferably, the binder is PVDF.
Preferably, the active material in the positive electrode is LiNixCoyMnzM1-x-y-zO2Or LiNixCoyAlzM1-x-y-zO2Wherein M is any one of Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, y is more than or equal to 0 and less than or equal to 1, x is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, x + y + z is less than or equal to 1, and a is more than or equal to 0 and less than or equal to 0<1, 0-b is less than or equal to 1, 0-c is less than or equal to 1, and a + b + c is less than or equal to 1. The value of y is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of x is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of z is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of x + y + z is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9; the value of a is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of b is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of c is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.; the value of a + b + c is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
Preferably, the active material in the anode: conductive agent: the binder is (80-98): (1-10), for example, 80:10:10, 82:9:9, 85:10:5, 88:6:6, 86:9:5, 90:5:5, 92:4:4, 93:4:3, 93:3:4, 94:3:3, 95:2.5:2.5, 97:1.5:1.5, 97:2:1 or 98:1:1, etc.
Preferably, the active material in the negative electrode is a silicon-carbon composite or a pure artificial graphite.
Preferably, the conductive agent is conductive carbon black Super-P.
Preferably, the binder is styrene butadiene rubber and/or carboxymethyl cellulose.
Preferably, the maximum charging voltage of the lithium ion battery is 4.45V to 5.0V, such as 4.5V, 4.55V, 4.6V, 4.65V, 4.7V, 4.75V, 4.8V, 4.85V, 4.9V, or 4.95V.
Compared with the prior art, the invention has the following beneficial effects:
(1) the present invention provides a novel lithium salt comprising Li2B12(CN)12And/or Li2CB11(CN)12The novel lithium salt is adopted to partially or completely replace halogen-containing salt (such as lithium hexafluorophosphate), so that the toxicity of the existing halogen-containing salt electrolyte can be effectively reduced.
(2) According to the invention, the novel lithium salt is added into the electrolyte of the battery, so that the high-voltage resistance of the battery is improved, and the obtained lithium ion battery can be used at high voltage of 4.45V or above; meanwhile, the high-temperature storage performance of the battery in a full-charge state can be improved, the cycle life of the battery at 45 ℃ can be prolonged, the safety of the battery is further improved, and the low-temperature performance of the battery cannot be influenced.
Drawings
FIG. 1 shows Li in the present invention2B12(CN)12The molecular structure model of (1);
FIG. 2 shows Li in the present invention2CB11(CN)12The molecular structure model of (1);
FIG. 3 is a comparison graph of EIS test patterns of the cell after capacity grading of comparative examples 1-4 and examples 1-3 of the invention.
Detailed Description
For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Comparative example 1
(1) Preparing a positive plate:
mixing a positive active material LiCoO in a mass ratio of 93:4:32Conductive carbon black Super-P and a binder polyvinylidene fluoride (PVDF), and then dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry, and the slurry is uniformly coatedDrying, rolling and vacuum drying the two surfaces of the aluminum foil, and welding aluminum tabs by using an ultrasonic welding machine to obtain a positive plate, wherein the thickness of the positive plate is 150 micrometers;
(2) preparing a negative plate:
mixing artificial graphite serving as a negative active material, conductive carbon black Super-P, Styrene Butadiene Rubber (SBR) serving as a binder and carboxymethyl cellulose (CMC) according to a mass ratio of 94:1:2.5:2.5, dispersing the mixed materials in deionized water to obtain negative slurry, coating the slurry on two sides of a copper foil, drying, rolling and vacuum drying, welding a nickel lug by using an ultrasonic welding machine to obtain a negative plate, wherein the thickness of the plate is 150 micrometers;
(3) preparing an electrolyte:
EC (ethylene carbonate), DEC (diethyl carbonate), PC (propylene carbonate) and PP (propyl propionate) are mixed according to the mass ratio EC: DEC: PC: PP ═ 1:3:1:4 to obtain a solvent accounting for 72.5 wt% of the mass percent of the electrolyte, PS (1, 3-propane sultone) accounting for 3.0 wt% of the mass percent of the electrolyte, FEC (fluoroethylene carbonate) accounting for 6.0 wt% of the mass percent of the electrolyte, ADN (adiponitrile) accounting for 2.0 wt%, EGBE (ethylene glycol dipropionitrilonitrile ether) accounting for 2.0 wt% of the mass percent of the electrolyte, HTCN (1,3, 6-hexanetrinitrile) accounting for 1.0 wt%, LiFSI (lithium bis-fluorosulfonylimide) accounting for 12.5 wt% of the mass percent of the electrolyte are added in sequence, and lithium hexafluorophosphate LiPF accounting for 12.5 wt% of the mass percent of the electrolyte is added6Fully mixing and dissolving for later use;
(4) preparing a battery:
placing a diaphragm with the thickness of 16 mu m between the positive plate and the negative plate, then winding a sandwich structure consisting of the positive plate, the negative plate and the diaphragm, flattening the wound body, then placing the flattened wound body into an aluminum-plastic film packaging bag, and baking the flattened wound body in vacuum at 80 ℃ for 48 hours to obtain a battery cell to be injected with liquid; respectively injecting the prepared electrolyte into a battery cell in a glove box with the dew point controlled below-40 ℃, carrying out vacuum packaging, standing for 24h, and then carrying out conventional formation and capacity grading according to the following steps: charging at 0.05C for 180min, charging at 0.2C to 3.95V, and vacuum sealing twice; further charging to 4.48V at a constant current of 0.2C, standing at normal temperature for 24h, and discharging to 3.0V at a constant current of 0.2C; and finally, charging the battery to 4.48V at a constant current of 1C for standby.
Comparative example 2
The difference from the comparative example 1 is that VC (vinylene carbonate) is added to the electrolyte in the step (3) in an amount of 1 wt% based on the total amount of the electrolyte in the comparative example 1.
Comparative example 3
The difference from the comparative example 1 is that FEC (fluoroethylene carbonate) is added to the electrolyte in the step (3) in an amount of 1 wt% based on the total amount of the electrolyte in the comparative example 1.
Comparative example 4
The difference from the comparative example 1 is that PS (1, 3-propane sultone) is added into the electrolyte in the step (3) and accounts for 1 wt% of the total weight of the electrolyte in the comparative example 1.
Example 1
The difference from the comparative example 1 is that Li is further added to the electrolyte in the step (3) in an amount of 1 wt% based on the total amount of the electrolyte in the comparative example 12B12(CN)12。
Example 2
The difference from the comparative example 1 is that Li is further added to the electrolyte in the step (3) in an amount of 1 wt% based on the total amount of the electrolyte in the comparative example 12CB11(CN)12。
Example 3
The difference from the comparative example 1 is that Li is further added to the electrolyte in the step (3) in an amount of 0.5 wt% based on the total amount of the electrolyte in the comparative example 12CB11(CN)12And Li in an amount of 0.5 wt% based on the total amount of the electrolyte of comparative example 12B12(CN)12。
Example 4
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement by 11.5 wt% lithium hexafluorophosphate LiPF6And Li in an amount of 1 wt% based on the total amount of the electrolyte2B12(CN)12。
Example 5
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 10.5 wt% lithium hexafluorophosphate LiPF6And mass accounts for electricityLi in an amount of 2 wt% based on the total amount of the electrolyte2B12(CN)12。
Example 6
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 8.5 wt% lithium hexafluorophosphate LiPF6And Li in an amount of 4 wt% based on the total amount of the electrolyte2B12(CN)12。
Example 7
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement by 4.5 wt% lithium hexafluorophosphate LiPF6And Li accounting for 8 wt% of the total electrolyte2B12(CN)12。
Example 8
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacing with Li accounting for 12.5 wt% of the total electrolyte2B12(CN)12。
Example 9
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement by 11.5 wt% lithium hexafluorophosphate LiPF6And Li in an amount of 1 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 10
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 10.5 wt% lithium hexafluorophosphate LiPF6And Li in an amount of 2 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 11
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 8.5 wt% lithium hexafluorophosphate LiPF6And Li in an amount of 4 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 12
Differs from comparative example 1 in the step (A)3) 12.5 wt% of lithium hexafluorophosphate LiPF in the electrolyte6Replacement by 4.5 wt% lithium hexafluorophosphate LiPF6And Li accounting for 8 wt% of the total electrolyte2CB11(CN)12。
Example 13
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacing with Li accounting for 12.5 wt% of the total electrolyte2CB11(CN)12。
Example 14
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement by 11.5 wt% lithium hexafluorophosphate LiPF6Li in an amount of 0.5 wt% based on the total amount of the electrolyte2B12(CN)12And Li in an amount of 0.5 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 15
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 10.5 wt% lithium hexafluorophosphate LiPF6Li in an amount of 1.0 wt% based on the total amount of the electrolyte2B12(CN)12And Li in an amount of 1.0 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 16
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement with 8.5 wt% lithium hexafluorophosphate LiPF6Li in an amount of 2.0 wt% based on the total amount of the electrolyte2B12(CN)12And Li in an amount of 2.0 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 17
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacement by 4.5 wt% lithium hexafluorophosphate LiPF6Li in an amount of 4.0 wt% based on the total amount of the electrolyte2B12(CN)12And Li in an amount of 4.0 wt% based on the total amount of the electrolyte2CB11(CN)12。
Example 18
Differs from the comparative example 1 in that 12.5 wt% of lithium hexafluorophosphate LiPF is contained in the electrolyte in the step (3)6Replacing with Li accounting for 6.25 wt% of the total electrolyte2B12(CN)12And Li accounting for 6.25 wt% of the total electrolyte2CB11(CN)12。
Performance testing
The batteries prepared in comparative examples 1 to 4 and examples 1 to 18 were subjected to the following performance tests.
(1) EIS Performance test
Taking the cell after grading of comparative examples 1-4 and examples 1-3 to perform EIS test, wherein the test conditions are as follows: the frequency range is 100 kHz-0.01 Hz, and the amplitude is 10 mV; the data after the test is derived, and the real part and the imaginary part are respectively used as an X axis and a Y axis for mapping analysis, and the result is shown in FIG. 3, and can be seen from FIG. 3: the electrolyte added with VC and PS can increase the battery impedance, and FEC and Li are added2CB11(CN)12、Li2CB11(CN)12The electrolyte of (1) reduces the battery impedance, to which Li is added2CB11(CN)12、Li2CB11(CN)12The resistance of the electrolyte is reduced more obviously;
(2) high temperature cycle performance test
The batteries prepared in comparative examples 1 to 4 and examples 1 to 18 were placed in an oven at a constant temperature of 45 ℃, and were charged to 4.48V at a constant current of 1C and then the constant voltage charging current was decreased to 0.02C, and then discharged to 3.0V at a constant current of 1C, and the cycle was repeated for 300 weeks, and the discharge capacity per week was recorded, and the capacity retention rate at high temperature cycle was calculated according to the following formula: the capacity retention ratio at n weeks was defined as discharge capacity at n week/discharge capacity at 1 week × 100%.
(3) Test of ordinary temperature cycle Performance
Taking the batteries prepared in comparative examples 1 to 4 and examples 1 to 18, charging the batteries to 4.48V at room temperature by a current of 1C at a constant current, then charging the batteries at a constant voltage until the current is reduced to 0.1C, then discharging the batteries to 3.0V at a current of 1C at a constant current, circulating the cycle for 300 weeks, recording the discharge capacity of each week, and calculating the capacity retention rate of the battery in normal-temperature cycle according to the following formula: the m-week capacity retention rate is m-week discharge capacity/1-week discharge capacity × 100%.
(4) Low temperature discharge performance test
At 25 ℃, the batteries formed in comparative examples 1 to 4 and examples 1 to 18 were charged to 4.48V with a constant current of 1C and a constant voltage, and then discharged to 3.0V with a constant current of 1C, and the discharge capacity was recorded; and then charging to 4.48V at constant current and constant voltage of 1C, standing for 4h in an environment at the temperature of minus 20 ℃, discharging to 3.0V at constant current of 0.2C, and recording the discharge capacity. Wherein the low-temperature discharge efficiency value at-20 ℃ is 0.2C discharge capacity (-20 ℃)/1C discharge capacity (25 ℃) multiplied by 100%;
(5) high temperature storage Performance test
At 25 ℃, the batteries formed in comparative examples 1 to 4 and examples 1 to 18 were charged to 4.48V with a constant current of 1C and a constant voltage, and then discharged to 3.0V with a constant current of 1C, and the discharge capacity was recorded; and then charging to 4.48V at constant current and constant voltage of 1C, standing for 4h in an environment at 85 ℃, discharging to 3.0V at constant current of 1C, and recording the discharge capacity. Wherein the capacity retention efficiency value is 1C discharge capacity (after 4h at 85 ℃)/1C discharge capacity (25 ℃) × 100%. The specific results of the above performance tests are shown in table 1.
TABLE 1
As can be seen from the data in table 1:
(1) li in electrolyte2B12(CN)12And/or Li2CB11(CN)12The addition of the electrolyte improves various performance indexes of the battery to different degrees. And, with Li2B12(CN)12And/or Li2CB11(CN)12Substituted LiPF6The battery performance is gradually improved with an increase in the ratio.
(2) Compared with the electrolyte added with single Li2B12(CN)12Or Li2CB11(CN)12When Li is added to the electrolyte2B12(CN)12And Li2CB11(CN)12The performance of the battery is correspondingly improved when the lithium salt is mixed, which is probably related to the synergistic effect of the two lithium salts. Considering that the synthesis of two lithium salts is costly and not suitable for adding too high a proportion at present, the scheme of adding a higher proportion is not implemented, but from the research result, a higher proportion of Li is added2B12(CN)12Or/and Li2CB11(CN)12The battery performance can be improved better.
(3) Addition of Li to electrolyte2B12(CN)12Or/and Li2CB11(CN)12Not only improves the cycle performance, but also shows excellent performance in high-temperature storage and low-temperature discharge. The results were consistent with the EIS test results and also indicate that the protective film formed by the addition of the two lithium salts was chemically more stable.
The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. The lithium ion battery electrolyte is characterized by comprising an organic solvent and a lithium salt, wherein the lithium salt comprises Li2B12(CN)12And/or Li2CB11(CN)12。
2. The lithium ion battery electrolyte of claim 1 wherein the lithium salt further comprises lithium hexafluorophosphate, or a mixed salt of lithium hexafluorophosphate and a doped lithium salt;
preferably, the doped lithium salt comprises Li2CB11H12、Li2B12H12、LiBH4、LiB3H8Any one or a combination of at least two of lithium difluorooxalate phosphate and lithium tetrafluorooxalate phosphate.
3. The lithium ion battery electrolyte of claim 1 or 2 wherein in the lithium ion battery electrolyte, Li2B12(CN)12The mass concentration percentage of the (B) is 0.1 wt% -20.0 wt%;
preferably, in the lithium ion battery electrolyte, Li2CB11(CN)12The mass concentration percentage of the (B) is 0.1 wt% -20.0 wt%;
preferably, the lithium salt includes Li2CB11(CN)12And Li2B12(CN)12In the lithium ion battery electrolyte, Li2CB11(CN)12And Li2B12(CN)12The total mass concentration percentage of the (B) is 0.1 wt% -20.0 wt%;
preferably, in the lithium ion battery electrolyte, the total mass concentration percentage of the lithium salt is 10.0 wt% to 20.0 wt%.
4. The lithium ion battery electrolyte of any one of claims 1-3, wherein the amount of organic solvent added to the lithium ion battery electrolyte is 57-85 wt% of the total mass of the lithium ion battery electrolyte;
preferably, the organic solvent comprises ethylene carbonate and/or propylene carbonate;
preferably, the organic solvent further comprises any one or a combination of at least two of diethyl carbonate, ethyl methyl carbonate, propyl propionate, ethyl propionate, propyl acetate, butyl butyrate, and ethyl butyrate.
5. The lithium ion battery electrolyte of any of claims 1-4 further comprising an additive;
preferably, the additive comprises vinylene carbonate, 1, 3-propane sultone, fluoroethylene carbonate, ethylene carbonate, 1, 3-propylene sultone, 1, 4-butane sultone, pentafluoroalkylcyclotriphosphazene, triallyl isocyanurate, ethyl 4,4, 4-trifluorobutyrate, 1,2, 2-tetrafluoroethyl-2, 2,3, 3-tetrafluoropropyl ether, any one or a combination of at least two of ethylene glycol dipropionitrile ether, 1,3, 6-hexanetricarbonitrile, adiponitrile, succinonitrile, citric anhydride, fluorobenzene, boron trifluoride tetrahydrofuran, tris (trimethylsilane) phosphate, tris (trimethylsilane) borate and methylene methanedisulfonate, preferably any one or a combination of at least two of vinylene carbonate, 1, 3-propanesultone and fluoroethylene carbonate;
preferably, in the lithium ion battery electrolyte, the content of the additive is 5-15 wt%.
6. A lithium ion battery, characterized in that the lithium ion battery comprises a lithium ion battery electrolyte according to any of claims 1 to 5.
7. The lithium ion battery of claim 6, further comprising a positive electrode, a negative electrode, and a separator.
8. The lithium ion battery of claim 6 or 7, wherein the active material in the positive electrode: conductive agent: the binder is (90-98), (1-5) and (1-5);
preferably, the conductive agent is conductive carbon black Super-P;
preferably, the binder is PVDF;
preferably, the active material in the positive electrode is LiNixCoyMnzM1-x-y-zO2Or LiNiaCobAlcN1-a-b-cO2Wherein M and N are respectively and independently selected from any one of Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, y is more than or equal to 0 and less than or equal to 1, x is more than or equal to 0 and less than 1, z is more than or equal to 0 and less than or equal to 1, x + y + z is less than or equal to 1, a is more than or equal to 0 and less than or equal to 1<1,0≤b≤1,0≤c≤1,a+b+c≤1。
9. The lithium ion battery of any of claims 6-8, wherein the active material in the negative electrode: conductive agent: the binder is (80-98), (1-10) and (1-10);
preferably, the active material in the negative electrode is a silicon-carbon composite material or pure artificial graphite;
preferably, the conductive agent is conductive carbon black Super-P;
preferably, the binder is styrene butadiene rubber and/or carboxymethyl cellulose.
10. The lithium ion battery of any of claims 6-9, wherein the lithium ion battery has a maximum charging voltage of 4.45V to 5.0V.
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114556662A (en) * | 2021-03-30 | 2022-05-27 | 宁德新能源科技有限公司 | Electrolyte and electrochemical device containing same |
EP4080638A4 (en) * | 2020-09-03 | 2024-07-17 | Lg Energy Solution Ltd | Lithium secondary battery |
US12148876B2 (en) | 2020-10-15 | 2024-11-19 | Ningde Amperex Technology Limited | Electrochemical apparatus and electronic apparatus |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002075441A (en) * | 2000-08-25 | 2002-03-15 | Sanyo Electric Co Ltd | Nonaqueous electrolyte cell |
US20110150736A1 (en) * | 2008-08-22 | 2011-06-23 | Yuji Hagiwara | Ionic compound, method for producing the same, and ion-conductive material comprising the same |
CN102948001A (en) * | 2010-06-22 | 2013-02-27 | 日本合成化学工业株式会社 | Electrolyte material, electrolyte for lithium secondary battery, lithium secondary battery using same, and novel lithium salt |
CN103840127A (en) * | 2012-11-22 | 2014-06-04 | 三星Sdi株式会社 | Positive active material layer for rechargeable lithium battery, separator for rechargeable lithium battery, and rechargeable lithium battery including at least one of same |
CN104937748A (en) * | 2013-02-27 | 2015-09-23 | 大曹株式会社 | Positive electrode and nonaqueous electrolyte secondary battery |
TW201611376A (en) * | 2014-06-04 | 2016-03-16 | 德山股份有限公司 | Non-aqueous electrolyte solution and electrical storage device using the same |
JP2017004638A (en) * | 2015-06-05 | 2017-01-05 | 株式会社トクヤマ | Electrolyte salt, non-aqueous electrolytic solution containing electrolyte salt, and power storage device using non-aqueous electrolytic solution |
CN107195966A (en) * | 2017-04-26 | 2017-09-22 | 湛江市金灿灿科技有限公司 | The high voltage tertiary cathode material system lithium-ion battery electrolytes that a kind of high/low temperature performance is taken into account |
CN107394267A (en) * | 2017-07-27 | 2017-11-24 | 湛江市金灿灿科技有限公司 | Electrolyte and lithium ion battery |
US20190036170A1 (en) * | 2016-02-09 | 2019-01-31 | Virginia Commonwealth University | Electrolytes containing superhalogens for metal ion batteries |
CN109461967A (en) * | 2018-11-01 | 2019-03-12 | 江西优锂新材股份有限公司 | A kind of nickelic tertiary cathode material electrolyte thereof and preparation method |
CN109546219A (en) * | 2018-12-19 | 2019-03-29 | 珠海光宇电池有限公司 | A kind of lithium-ion battery electrolytes and the lithium ion battery using the electrolyte |
JP2019064923A (en) * | 2016-02-18 | 2019-04-25 | 株式会社トクヤマ | Ionic compound, nonaqueous electrolyte including ionic compound and electricity storage device using nonaqueous electrolyte |
CN110048164A (en) * | 2019-05-16 | 2019-07-23 | 东莞维科电池有限公司 | A kind of Soft Roll lithium ion silicon-carbon battery electrolyte and lithium ion battery |
-
2019
- 2019-10-23 CN CN201911013607.2A patent/CN110611123A/en active Pending
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002075441A (en) * | 2000-08-25 | 2002-03-15 | Sanyo Electric Co Ltd | Nonaqueous electrolyte cell |
US20110150736A1 (en) * | 2008-08-22 | 2011-06-23 | Yuji Hagiwara | Ionic compound, method for producing the same, and ion-conductive material comprising the same |
CN102948001A (en) * | 2010-06-22 | 2013-02-27 | 日本合成化学工业株式会社 | Electrolyte material, electrolyte for lithium secondary battery, lithium secondary battery using same, and novel lithium salt |
CN103840127A (en) * | 2012-11-22 | 2014-06-04 | 三星Sdi株式会社 | Positive active material layer for rechargeable lithium battery, separator for rechargeable lithium battery, and rechargeable lithium battery including at least one of same |
CN104937748A (en) * | 2013-02-27 | 2015-09-23 | 大曹株式会社 | Positive electrode and nonaqueous electrolyte secondary battery |
TW201611376A (en) * | 2014-06-04 | 2016-03-16 | 德山股份有限公司 | Non-aqueous electrolyte solution and electrical storage device using the same |
JP2017004638A (en) * | 2015-06-05 | 2017-01-05 | 株式会社トクヤマ | Electrolyte salt, non-aqueous electrolytic solution containing electrolyte salt, and power storage device using non-aqueous electrolytic solution |
US20190036170A1 (en) * | 2016-02-09 | 2019-01-31 | Virginia Commonwealth University | Electrolytes containing superhalogens for metal ion batteries |
JP2019064923A (en) * | 2016-02-18 | 2019-04-25 | 株式会社トクヤマ | Ionic compound, nonaqueous electrolyte including ionic compound and electricity storage device using nonaqueous electrolyte |
CN107195966A (en) * | 2017-04-26 | 2017-09-22 | 湛江市金灿灿科技有限公司 | The high voltage tertiary cathode material system lithium-ion battery electrolytes that a kind of high/low temperature performance is taken into account |
CN107394267A (en) * | 2017-07-27 | 2017-11-24 | 湛江市金灿灿科技有限公司 | Electrolyte and lithium ion battery |
CN109461967A (en) * | 2018-11-01 | 2019-03-12 | 江西优锂新材股份有限公司 | A kind of nickelic tertiary cathode material electrolyte thereof and preparation method |
CN109546219A (en) * | 2018-12-19 | 2019-03-29 | 珠海光宇电池有限公司 | A kind of lithium-ion battery electrolytes and the lithium ion battery using the electrolyte |
CN110048164A (en) * | 2019-05-16 | 2019-07-23 | 东莞维科电池有限公司 | A kind of Soft Roll lithium ion silicon-carbon battery electrolyte and lithium ion battery |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP4080638A4 (en) * | 2020-09-03 | 2024-07-17 | Lg Energy Solution Ltd | Lithium secondary battery |
US12148876B2 (en) | 2020-10-15 | 2024-11-19 | Ningde Amperex Technology Limited | Electrochemical apparatus and electronic apparatus |
CN114556662A (en) * | 2021-03-30 | 2022-05-27 | 宁德新能源科技有限公司 | Electrolyte and electrochemical device containing same |
WO2022204980A1 (en) * | 2021-03-30 | 2022-10-06 | 宁德新能源科技有限公司 | Electrolyte and electrochemical device containing electrolyte |
EP4300651A4 (en) * | 2021-03-30 | 2024-05-08 | Ningde Amperex Technology Limited | Electrolyte and electrochemical device containing electrolyte |
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