CN116979145A - Electrolyte, electrochemical device, and electronic device - Google Patents
Electrolyte, electrochemical device, and electronic device Download PDFInfo
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- CN116979145A CN116979145A CN202210458733.4A CN202210458733A CN116979145A CN 116979145 A CN116979145 A CN 116979145A CN 202210458733 A CN202210458733 A CN 202210458733A CN 116979145 A CN116979145 A CN 116979145A
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- 125000001971 neopentyl group Chemical group [H]C([*])([H])C(C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 125000002868 norbornyl group Chemical group C12(CCC(CC1)C2)* 0.000 description 1
- 125000002347 octyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000006259 organic additive Substances 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 1
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 description 1
- 229920000120 polyethyl acrylate Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229930195734 saturated hydrocarbon Natural products 0.000 description 1
- 150000003346 selenoethers Chemical class 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
Abstract
Embodiments of the present disclosure provide an electrolyte, an electrochemical device, and an electronic device. The electrolyte comprises a compound represented by a formula I,
Description
Technical Field
Example embodiments of the present disclosure relate generally to the field of energy storage technology, and in particular, to an electrolyte, an electrochemical device, and an electronic device.
Background
With the dramatic decrease in global fossil energy and the increase in greenhouse effect, lithium ion batteries as new energy storage devices are an important form of future energy supply. The lithium ion battery has the advantages of high energy density, low memory effect, environmental friendliness, long service life and the like, and is widely applied to the field of electrochemical energy storage. In particular, in the automotive industry, two of the most urgent requirements of electric vehicles on power batteries at present are fast charging capability and high safety. The current mainstream strategy to improve the fast charge capability of power cells is to use a high kinetic electrolyte, which however tends to lead to significant deterioration of cycle life and high temperature characteristics. In addition, the flame-retardant electrolyte is also a battery cell safety improvement strategy of the current industry main attack, but the battery cell impedance is obviously increased, so that the cycle life is drastically reduced.
Therefore, there is a need to develop a solution that combines both the fast charge capability and the high safety of lithium ion batteries.
Disclosure of Invention
It is an object of the present disclosure to provide an electrolyte, an electrochemical device and an electronic device, which at least partially solve the above-mentioned problems existing in the prior art.
According to a first aspect of the present disclosure, there is provided an electrolyte comprising a compound represented by formula I,
In the case of the formula I,
r1, R2 and R3 are each independently selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a substituted or unsubstituted C2-C4 alkenylene group, and a heteroatom, wherein the heteroatom includes at least one of an O atom, an S atom, and an N atom, and when substituted, the substituent includes at least one of an F atom, a sulfonyl group, a cyano group, and an alkoxy group;
r4 is selected from any one of substituted or unsubstituted C1-C4 alkyl, N atom, P atom and B atom, wherein when substituted, the substituent comprises at least one of C2-C4 alkenyl, C2-C4 alkynyl, F atom and derivatives thereof, sulfonyl, cyano and alkoxy; and
x1 is selected from any one of P atom, B atom and P or B containing group.
In some embodiments, the compound represented by formula I includes at least one of compounds represented by formulas I-1 through I-8:
in some embodiments, the compound represented by formula I is present in an amount of 0.1% to 2% by mass based on the total mass of the electrolyte.
In some embodiments, the electrolyte further comprises a compound represented by formula II,
in formula II, R5 is selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a C2-C4 alkenyl group, a C2-C4 alkynyl group, an O atom, an S atom and an N atom, wherein when substituted, the substituent includes at least one of an F atom, a sulfonyl group and a cyano group.
In some embodiments, the compound represented by formula II includes at least one of compounds represented by formulas II-1 to II-8:
in some embodiments, the total mass percent of both the compound represented by formula I and the compound represented by formula II is from 0.01% to 20%, based on the total mass of the electrolyte.
In some embodiments, the compound represented by formula I is present in an amount of 0.1% to 2% by mass based on the total mass of the electrolyte.
In some embodiments, the compound represented by formula II is present in an amount of 0.1% to 5% by mass based on the total mass of the electrolyte.
According to a second aspect of the present disclosure, there is provided an electrochemical device including a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte according to the first aspect of the present disclosure.
According to a third aspect of the present disclosure, there is provided an electronic device comprising an electrochemical device according to the second aspect of the present disclosure.
In the embodiment according to the disclosure, by introducing the compound represented by the formula I and the optional additive such as the compound represented by the formula II into the electrolyte, a fast ion transmission channel can be formed at an electrode interface in the preparation process of the battery cell, so that the impedance of the battery cell is remarkably reduced. In addition, the fast ion transmission channel has good thermal stability and voltage stability at high temperature, can inhibit high-temperature high-voltage gas generation and inhibit self-heating rate of the battery cell in the process of heat abuse.
This content section is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This section is not intended to identify key features or essential features of the disclosure, nor is it intended to be used to limit the scope of the disclosure.
Detailed Description
In order to make the objects, technical solutions and advantages of the present disclosure more apparent, the technical solutions of the present disclosure will be clearly and completely described in connection with example embodiments. It should be understood that the described embodiments are some, but not all, of the embodiments of the present disclosure. The related embodiments described herein are of illustrative nature and are intended to provide a basic understanding of the present disclosure. The embodiments of the present disclosure should not be construed as limiting the present disclosure. Based on the technical solution provided in the present disclosure and the embodiments given, all other embodiments obtained by a person skilled in the art without making any creative effort are within the scope of protection of the present disclosure.
In this document, a list of items connected by the terms "any of," "any of," or other similar terms may mean any of the listed items. For example, if items A and B are listed, then the phrase "either of A and B" means either only A or only B. In another example, if items A, B and C are listed, then the phrase "any of A, B and C" means only a; only B; or only C. Item a may comprise a single element or multiple elements. Item B may comprise a single element or multiple elements. Item C may comprise a single element or multiple elements.
In this document, a list of items connected by the terms "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items a and B are listed, the phrase "at least one of a and B" means only a; only B; or A and B. In another example, if items A, B and C are listed, then the phrase "at least one of A, B and C" means only a; or only B; only C; a and B (excluding C); a and C (excluding B); b and C (excluding A); or A, B and C. Item a may comprise a single element or multiple elements. Item B may comprise a single element or multiple elements. Item C may comprise a single element or multiple elements.
Herein, for simplicity, a "Cn-Cm" group refers to a group having "n" to "m" carbon atoms, where "n" and "m" are integers. For example, "C1-C10" alkyl refers to an alkyl group having 1 to 10 carbon atoms.
In this context, the term "alkyl" is intended to be a straight chain saturated hydrocarbon structure having from 1 to 20 carbon atoms. "alkyl" is also intended to be a branched or cyclic hydrocarbon structure having 3 to 20 carbon atoms. For example, the alkyl group may be an alkyl group of 1 to 20 carbon atoms, an alkyl group of 1 to 10 carbon atoms, an alkyl group of 1 to 5 carbon atoms, an alkyl group of 5 to 20 carbon atoms, an alkyl group of 5 to 15 carbon atoms, or an alkyl group of 5 to 10 carbon atoms. When alkyl groups having a specific carbon number are specified, all geometric isomers having that carbon number are contemplated; thus, for example, reference to "butyl" is intended to include n-butyl, sec-butyl, isobutyl, tert-butyl and cyclobutyl; "propyl" includes n-propyl, isopropyl and cyclopropyl. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, octyl, cyclopropyl, cyclobutyl, norbornyl, and the like. In addition, the alkyl group may be optionally substituted or unsubstituted.
Herein, the term "alkenyl" refers to a monovalent unsaturated hydrocarbon group that may be straight or branched and has at least one, and typically 1, 2, or 3 carbon-carbon double bonds. Unless otherwise defined, the alkenyl group typically contains 2 to 20 carbon atoms, for example, can be an alkenyl group of 2 to 20 carbon atoms, an alkenyl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 10 carbon atoms, or an alkenyl group of 2 to 6 carbon atoms. Representative alkenyl groups include, for example, vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but-3-enyl, n-hex-3-enyl, and the like. In addition, alkenyl groups may optionally be substituted or unsubstituted.
Herein, the term "alkenylene" encompasses both straight and branched chain alkenylenes. When an alkenylene group having a specific carbon number is specified, all geometric isomers of the alkenylene group having that carbon number are contemplated. For example, the alkenylene group may be an alkenylene group of 2 to 20 carbon atoms, an alkenylene group of 2 to 15 carbon atoms, an alkenylene group of 2 to 10 carbon atoms, an alkenylene group of 2 to 5 carbon atoms, an alkenylene group of 5 to 20 carbon atoms, an alkenylene group of 5 to 15 carbon atoms, or an alkenylene group of 5 to 10 carbon atoms. Representative alkylene groups include, for example, vinylidene, propenylene, butenylene, and the like. In addition, alkenylene groups may be optionally substituted or unsubstituted.
Herein, the term "alkynyl" refers to a monovalent unsaturated hydrocarbon group that may be straight or branched and has at least one and typically 1, 2, or 3 carbon-carbon triple bonds. Unless otherwise defined, the alkynyl group typically contains 2 to 20 carbon atoms, for example, an alkynyl group which may be 2 to 20 carbon atoms, an alkynyl group of 6 to 20 carbon atoms, an alkynyl group of 2 to 10 carbon atoms, or an alkynyl group of 2 to 6 carbon atoms. Representative alkynyl groups include, for example, ethynyl, prop-2-ynyl (n-propynyl), n-but-2-ynyl, n-hex-3-ynyl, and the like. In addition, alkynyl groups may optionally be substituted or unsubstituted.
Herein, the term "heteroatom" means an atom other than C, H. For example, the heteroatom may comprise at least one of B, N, O, si, P, S.
In this context, the term "cyano" encompasses organics containing an organic group-CN.
Herein, the term "alkoxy" refers to an L-O group, wherein L is an alkyl group. The alkoxy group herein may be an alkoxy group of 1 to 12 carbon atoms, and may also be an alkoxy group of 1 to 10 carbon atoms, an alkoxy group of 1 to 5 carbon atoms, an alkoxy group of 5 to 12 carbon atoms, or an alkoxy group of 5 to 10 carbon atoms.
As described hereinabove, the two most urgent demands of electric vehicles on power batteries are rapid charging capability and high safety.
In order to solve the problem of rapid charging, many efforts are made in the industry, for example, measures such as low doping coating materials, particle size optimization and the like are adopted for the positive electrode, and high dynamic solvents (such as methyl ethyl carbonate, dimethyl carbonate and the like) are mainly introduced for the electrolyte. The fast charging capability of the battery cell is improved most obviously by using the high-dynamic solvent, but the cycle performance and the high-temperature storage performance of the battery cell are often obviously deteriorated due to the strong self-reactivity of the high-dynamic solvent. Similar problems are encountered with low doped cladding materials.
In addition, for high safety cells, much research in the industry is currently focused on flame retardant electrolytes. The flame-retardant electrolyte is mostly prepared from additives or solvents containing free radical quenching groups, and the additives and solvents have poor compatibility with the anode material, so that the cycle performance and the dynamic performance are greatly reduced.
In order to solve the above-described problems in the prior art, embodiments of the present disclosure provide an electrolyte.
[ electrolyte ]
The electrolyte of embodiments of the present disclosure includes an organic solvent, an electrolyte, and an additive.
1. Organic solvents
In the embodiments according to the present disclosure, there is no particular limitation on the kind of the organic solvent, and it may be selected and customized according to the system requirements. For example, nonaqueous organic solvent systems may be employed. The nonaqueous organic solvent system may include any of a variety of carbonate, carboxylate, nitrile, sulfone, and ether solvents. The carbonates may include cyclic carbonates and chain carboxylates, and halogenated derivatives thereof, or mixtures thereof in any ratio. Specifically, the organic solvent may be at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylethyl carbonate, methyl formate, ethyl acetate, propyl propionate, ethyl propionate, γ -butyrolactone, and tetrahydrofuran. It should be understood that various other types of organic solvents are also possible, and the scope of the present disclosure is not strictly limited in this respect.
2. Electrolyte composition
In embodiments according to the present disclosure, the electrolyte may be of various useful types, such as a solid electrolyte, a gel electrolyte, or a liquid electrolyte.
In one embodiment, when the electrolyte is a liquid electrolyte, the mass of the liquid electrolyte may be 5% -23% of the total mass of the electrolyte. Preferably, the mass of the liquid electrolyte may be 9% -16% of the total weight of the electrolyte. In one embodiment, the liquid electrolyte may be selected from at least one of lithium salt and sodium salt. The kind of lithium salt is not particularly limited and may be selected according to actual demands. Preferably, the lithium salt may include at least LiPF 6 . The lithium salt may further comprise LiBF 4 、LiClO 4 、LiAsF 6 、LiBOB、LiDFOB、LiFSI、LiTFSI、LiPO 2 F 2 、LiTFOP、LiN(SO 2 RF) 2 、LiN(SO 2 F)(SO 2 RF), wherein rf=c n F 2n+1 Represents a perfluoroalkyl group, and n is an integer of 1 to 10. The type of sodium salt is not particularly limited, and can be selected according to actual requirements. Preferably, the sodium salt may be selected from the group consisting of NaPF 6 、NaBF 4 、NaClO、NaAsF 6 、NaCF 3 SO 3 、NaN(CF 3 SO 2 ) 2 、NaN(C 2 F 5 SO 2 ) 2 、NaN(FSO 2 ) 2 At least one of them.In other embodiments, the liquid electrolyte may be of other types than lithium and sodium salts, and the scope of the present disclosure is not strictly limited in this respect.
Similarly, in embodiments according to the present disclosure, there is also no strict limitation on the type of solid electrolyte and gel electrolyte, and various conventional or future available solid electrolytes and gel electrolytes are possible.
3. Additive agent
In some embodiments, the additive comprises a first additive, the first additive being a compound represented by formula I,
in the case of the formula I,
r1, R2 and R3 are each independently selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a substituted or unsubstituted C2-C4 alkenylene group, and a heteroatom, wherein the heteroatom includes at least one of an O atom, an S atom, and an N atom, and when substituted, the substituent includes at least one of an F atom, a sulfonyl group, a cyano group, and an alkoxy group;
r4 is selected from any one of substituted or unsubstituted C1-C4 alkyl, N atom, P atom and B atom, wherein when substituted, the substituent comprises at least one of C2-C4 alkenyl, C2-C4 alkynyl, F atom and derivatives thereof, sulfonyl, cyano and alkoxy; and
x1 is selected from any one of P atom, B atom and P or B containing group.
In some embodiments, the first additive comprises at least one of the compounds represented by formulas I-1 through I-8:
by adding the first additive into the electrolyte, the impedance of the battery cell can be obviously reduced, and the cycle capacity retention rate and the high-temperature storage performance can be improved.
In some embodiments, the first additive is present in an amount of 0.1% to 2% by mass based on the total mass of the electrolyte.
In some embodiments, the electrolyte further comprises a second additive, the second additive being a compound represented by formula II,
in formula II, R5 is selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a C2-C4 alkenyl group, a C2-C4 alkynyl group, an O atom, an S atom and an N atom, wherein when substituted, the substituent includes at least one of an F atom, a sulfonyl group and a cyano group.
In some embodiments, the second additive comprises at least one of the compounds represented by formulas II-1 through II-8:
by introducing the first additive and the second additive into the electrolyte, the first additive and the second additive can cooperate in the preparation process of the battery cell to form a fast ion transmission channel at the interface of the electrode, so that the impedance of the battery cell is obviously reduced. In addition, the fast ion transmission channel has good thermal stability and voltage stability at high temperature, can inhibit high-temperature high-voltage gas generation and inhibit self-heating rate of the battery cell in the process of heat abuse.
In some embodiments, the total mass percent of both the first additive and the second additive is from 0.01% to 20% based on the total mass of the electrolyte.
In some embodiments, the first additive is present in an amount of 0.1% to 2% by mass based on the total mass of the electrolyte.
In some embodiments, the second additive is present in an amount of 0.1% to 5% by mass based on the total mass of the electrolyte.
When the mass of the first additive accounts for 0.1-2% of the electrolyte and the mass of the second additive accounts for 0.1-5% of the electrolyte, the first additive and the second additive can form a film on the surfaces of the positive electrode and the negative electrode in a synergic mode due to the coupling difference of oxidation-reduction potentials, the interface film generated by the synergic mode is rich in fast ion conducting groups such as N, B and the like, the impedance can be obviously reduced, the interface film generated by the synergic mode is uniform, the high-temperature stability is good, the side reaction at high temperature is restrained, and meanwhile, the temperature rise accompanied by the side reaction is restrained; both the first additive and the second additive can capture free Lewis acid (Lewis acid), reducing the reactivity of the electrolyte itself.
4. Preparation of electrolyte
In some embodiments, the electrolyte may be prepared using the following procedure: in a dry argon glove box, the organic solvent, additives, and electrolyte were mixed in the desired amounts. Specifically, an organic solvent is firstly added into a dry argon glove box, then an additive is added, electrolyte is added after dissolution and full stirring, and the electrolyte is obtained after uniform mixing.
It should be appreciated that other methods or in other environments may also be employed to prepare the electrolyte in embodiments according to the present disclosure, the scope of the present disclosure is not strictly limited in this respect.
[ electrochemical device ]
Embodiments of the present disclosure provide an electrochemical device, such as a primary battery or a secondary battery. The secondary battery is, for example, a lithium ion battery, a sodium ion battery, a zinc ion battery, or a supercapacitor. In the embodiments of the present disclosure, the principles of the present disclosure are described only with lithium ion batteries as examples, but the scope of the present disclosure is not limited thereto.
The electrochemical device includes an electrolyte of an embodiment of the present disclosure. In addition, the electrochemical device may further include a positive electrode sheet, a negative electrode sheet, a separator, a case, and the like.
1. Positive plate
The positive electrode sheet is a positive electrode sheet that is well known in the art and can be used in an electrochemical device. In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
The positive electrode current collector is a supporting layer that is conductive and does not react with other components of the electrochemical device. In some embodiments, the positive electrode current collector comprises a metal, including but not limited to aluminum foil.
The positive electrode active material layer is disposed on the surface of the positive electrode current collector. The positive electrode active material layer contains a positive electrode active material, and may further contain a binder and a conductive agent. The positive electrode active material may be selected from materials known in the art that can be used as an electrochemical device for lithium ion deintercalation.
In some embodiments, the positive electrode active material may be selected from LiMnO 2 、LiMn 2 O 4 、LiNi 1-x Co x O 2 、LiCo 1- x Mn x O 2 、LiNi 1-x Mn x O 2 (0<x<1)、Li(Ni x Co y Mn z )O 4 (0<x<1,0<y<1,0<z<1,0<x+y+z<1)、LiMn 2-a Ni a O 4 、LiMn 2-a Co a O 4 (0<a<2)、LiMPO 4 (M is at least one selected from Co, ni, fe, mn, V), spinel material LiMn 2 O 4 Layered material lithium cobalt oxide (LiCoO) 2 ) Lithium nickelate (LiNiO) 2 )、Li a Ni x A y B (1-x-y) O 2 (0.95.ltoreq.a.ltoreq.1, A and B may be independently selected from any one of Co, mn, al, and A and B are different, 0 < x < 1,0 < y < 1,0 < x+y < 1). In some embodiments, the positive electrode active material may also include at least one of sulfide, selenide, and halide.
In some embodiments, the positive electrode active material also has a coating layer on its surface, or is mixed with a material having a coating layer. In some embodiments, the coating layer comprises at least one coating element compound selected from oxides, hydroxides, oxyhydroxides, oxycarbonates, hydroxycarbonates of the coating element. In some embodiments, the compound used for the cladding layer may be crystalline or amorphous. In some embodiments, the cladding elements for the cladding layer include Mg, al, co, K, na, ca, si, ti, V, sn, ge, ga, B, as, zr or any mixture thereof. In some embodiments, the coating layer may be formed by any method as long as the properties of the positive electrode active material are not adversely affected by including the element in the compound.
In some embodiments, the positive electrode active material layer further includes a positive electrode binder and a positive electrode conductive agent. The positive electrode binder is used to improve the binding properties of the positive electrode active material particles with each other and with the positive electrode current collector. In some embodiments, the positive electrode binder includes at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethyleneoxy-containing polymer, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber of acrylic acid (ester), epoxy resin, nylon. The positive electrode conductive agent is used to provide conductivity to the electrode, and may include any conductive material as long as it does not chemically react with the active material. In some embodiments, the positive electrode conductive agent is at least one of natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, metal powder, metal fiber, and polyphenylene derivative. In some embodiments, the metal in the metal powder, metal fibers comprises at least one of copper, nickel, aluminum, silver.
In some embodiments, the method of preparing the positive electrode sheet is a method of preparing a positive electrode sheet that is well known in the art and that can be used in electrochemical devices. For example, the positive electrode active material, the conductive agent, and the binder may be mixed in a predetermined ratio as needed, and stirred; then adding a non-aqueous solvent, stirring and dispersing to obtain target slurry; then, coating, drying and rolling are carried out to obtain the target positive plate.
In some embodiments, the positive electrode sheet may be prepared using the following procedure (environmental requirements: humidity below 10%, temperature 20-30 ℃):
uniformly coating a super-P conductive solution with the solid content of 65% on the surface of an anode aluminum foil to obtain an aluminum foil containing a conductive coating: active material Li (Ni) 0.8 Co 0.1 Mn 0.1 )O 2 The conductive agent Super-P and the binder polyvinylidene fluoride are prepared according to the mass ratio of 96:2.2:1.8, mixing, adding N-methyl pyrrolidone, stirring and dispersing to obtain target slurry, and uniformly coating the obtained slurry on an aluminum foil;
drying the coated aluminum foil at high temperature, cold pressing, cutting, slitting, and drying for 12 hours at the temperature of 85 ℃ under vacuum condition to obtain a positive electrode plate;
and rolling, slitting and cutting the obtained pole piece to obtain the target pole piece.
2. Negative plate
The negative electrode sheet is a negative electrode sheet that can be used in an electrochemical device, as known in the art. In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
The negative electrode current collector is a supporting layer that is conductive and does not react with other components of the electrochemical device. In some embodiments, the negative current collector comprises a metal, including but not limited to copper foil.
The anode active material layer is disposed on the surface of the anode current collector. The anode active material layer contains an anode active material. The negative electrode active material may be selected from various negative electrode active materials known in the art that can be used as an electrochemical device. The active material includes, for example, a material capable of reversibly intercalating and deintercalating active ions or a material capable of reversibly doping and deintercalating active ions.
In some embodiments, the negative electrode active material includes at least one of lithium metal, a lithium metal alloy, a carbon material, and a silicon-based material. In some embodiments, the lithium metal alloy comprises an alloy of lithium and a metal selected from Na, K, rb, cs, fr, be, mg, ca, sr, si, sb, in, zn, ba, ra, ge, al, sn.The carbon material may be selected from various carbon materials known in the art that can be used as a carbon-based anode active material of an electrochemical device. In some embodiments, the carbon material comprises at least one of crystalline carbon, amorphous carbon. In some embodiments, the crystalline carbon is natural graphite or synthetic graphite. In some embodiments, the crystalline carbon is amorphous, plate-shaped, platelet-shaped, spherical, or fibrous in shape. In some embodiments, the crystalline carbon is a low crystalline carbon or a high crystalline carbon. In some embodiments, the low crystalline carbon comprises at least one of soft carbon, hard carbon. In some embodiments, the high crystalline carbon comprises at least one of natural graphite, crystalline graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesophase carbon microbeads, mesophase pitch, high temperature calcined carbon. In some embodiments, the high temperature calcined carbon is petroleum or coke derived from coal tar pitch. In some embodiments, the amorphous carbon comprises at least one of soft carbon, hard carbon, mesophase pitch carbonized product, and fired coke. In some embodiments, the anode active material comprises a transition metal oxide. In some embodiments, the anode active material comprises Si, siO x (0 < x < 2), si/C composite, si-Q alloy, sn, snO z At least one of Sn-C compound and Sn-R alloy, wherein Q is at least one selected from alkali metals, alkaline earth metals, 13 th to 16 th group elements, transition elements and rare earth elements, and Q is not Si, R is at least one selected from alkali metals, alkaline earth metals, 13 th to 16 th group elements, transition elements and rare earth elements, and R is not Sn. In some embodiments, Q and R comprise at least one of Mg, ca, sr, ba, sc, Y, ti, zr, hf, rf, V, nb, ta, db, cr, mo, W, sg, tc, re, bh, fe, pb, ru, os, hs, rh, ir, pd, pt, cu, ag, au, zn, cd, B, al, ga, sn, in, tl, ge, P, as, sb, bi, S, se, te, po.
In some embodiments, the anode active material layer further comprises an anode binder and an anode conductive agent. In some embodiments, the negative electrode binder comprises at least one of a vinylidene fluoride-hexafluoropropylene copolymer (PVDF-Co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethyleneoxy-containing polymer, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber of acrylic acid (ester), epoxy resin, nylon. In some embodiments, the negative electrode conductive agent is used to provide conductivity to the electrode, and may comprise any conductive material so long as it does not react with other components of the electrochemical device. In some embodiments, the negative electrode conductive agent comprises any one of a carbon-based material, a metal-based material, a conductive polymer, or a mixture thereof. In some embodiments, the carbon-based material comprises at least one of natural graphite, synthetic graphite, carbon black, acetylene black, ketjen black, carbon fiber. In some embodiments, the metal-based material comprises at least one of a metal powder or metal fiber of copper, nickel, aluminum, silver, or the like. In some embodiments, the conductive polymer comprises a polyphenylene derivative.
In some embodiments, the method of preparing the negative electrode sheet is a method of preparing a negative electrode sheet that can be used in an electrochemical device, as is known in the art. In some embodiments, in the preparation of the anode slurry, a solvent is generally added, and the anode active material is added to a binder and, if necessary, a conductive material and a thickener, and then dissolved or dispersed in the solvent to prepare the anode slurry. The solvent is volatilized during the drying process. The solvent is a solvent known in the art that can be used as the anode active material layer, and includes, but is not limited to, water. The thickener is a thickener known in the art to be useful as a negative electrode active material layer, and includes, but is not limited to, sodium carboxymethyl cellulose.
The embodiment of the present disclosure is not particularly limited in the mixing ratio of the anode active material, the binder, and the thickener in the anode active material layer, and the mixing ratio thereof may be controlled according to desired electrochemical device performance.
In some embodiments, the negative electrode sheet may be prepared using the following procedure:
the negative electrode active material artificial graphite, a conductive agent Super-P, a thickener sodium carboxymethyl cellulose (CMC) and a binder styrene-butadiene rubber are mixed according to the mass ratio of 96.2:2:0.8:1, mixing, adding deionized water, and obtaining negative electrode slurry under the action of a vacuum stirrer, wherein the solid content of the negative electrode slurry is 54wt%;
Uniformly coating the negative electrode slurry on a negative electrode current collector copper foil;
and (3) drying the coated copper foil at high temperature, cold pressing, cutting and slitting, and then drying for 12 hours under the vacuum condition at 120 ℃ to obtain the negative plate.
3. Isolation film
Separator membranes are well known in the art as separator membranes that can be used in electrochemical devices, including but not limited to microporous membranes of the polyolefin type. In some embodiments, the barrier film comprises at least one of Polyethylene (PE), ethylene-propylene copolymer, polypropylene (PP), ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-methacrylate copolymer.
In some embodiments, the separator is a single layer separator or a multilayer separator.
In some embodiments, the separator is coated with a coating. In some embodiments, the coating comprises at least one of an organic coating and an inorganic coating, wherein the organic coating is selected from at least one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic-styrene copolymer, polydimethylsiloxane, sodium polyacrylate, sodium carboxymethyl cellulose, and the inorganic coating is selected from SiO 2 、Al 2 O 3 、CaO、TiO 2 、ZnO 2 、MgO、ZrO 2 、SnO 2 At least one of them.
The embodiment of the present disclosure is not particularly limited in terms of the form and thickness of the separator. The method of preparing the separator is a method of preparing a separator that can be used in an electrochemical device, which is well known in the art.
In embodiments according to the present disclosure, the release film may be prepared using the following procedure: selecting polyethylene isolating film with thickness of 9um, passing through PVDF slurry and inorganic particles (sheet shape)Boehmite and Al 2 O 3 The mass ratio of (2) is 70:30 And (3) coating and drying the slurry to obtain the final isolating film, wherein the thickness of the coating is 3um, and the porosity of the membrane is 55%.
4. Preparation of electrochemical device
In some embodiments, an electrochemical device (e.g., a lithium-ion battery) may be prepared using the following procedure: sequentially stacking the positive plate, the isolating film and the negative plate, so that the isolating film is positioned between the positive plate and the negative plate to play a role in isolation; then winding the positive plate, the isolating film and the negative plate to obtain a bare cell, welding the tab, and placing the obtained bare cell in an aluminum-plastic film of an outer package; the electrolyte according to the embodiment of the present disclosure is injected into the dried bare cell, and the target cell, i.e., the electrochemical device, is obtained through the processes of vacuum packaging, standing, formation (e.g., 0.02C constant current to 3.3V, and then 0.1C constant current to 3.6V), shaping, capacity testing, and the like.
[ test of Electrical Properties of electrochemical device ]
Hereinafter, the electrical performance test results of the electrochemical device will be described using a lithium ion battery as an example. The lithium ion battery comprises a positive plate, a negative plate, a separation film and electrolyte according to the embodiment of the disclosure.
In the examples and comparative examples described below, reagents, materials and instruments used were commercially available or synthetically obtained unless otherwise specified. The specific reagents used in the electrolyte are as follows:
a first additive:
and a second additive:
organic solvent: ethylene carbonate (abbreviated EC), diethyl carbonate (abbreviated DEC), ethylmethyl carbonate (EMC);
an electrolyte: and (3) a lithium salt.
Both the first additive and the second additive are commercially available or may be synthetically obtained by methods of preparation well known and conventional in the art.
The lithium ion batteries of examples 1 to 12 and comparative examples 1 to 7 in tables 1 to 3 described below can each be produced according to the following method.
(1) Preparation of a positive plate: uniformly coating the surface of positive aluminum foil with super-P conductive solution with 65% solid content in the environment with humidity lower than 10% and temperature of 20-30deg.C to obtain aluminum foil containing conductive coating, specifically active material Li (Ni 0.8 Co 0.1 Mn 0.1 )O 2 The conductive agent Super-P and the binder polyvinylidene fluoride are prepared according to the mass ratio of 96:2.2:1.8, mixing, adding N-methyl pyrrolidone, stirring and dispersing to obtain target slurry, and uniformly coating the obtained slurry on an aluminum foil; drying the coated aluminum foil at high temperature, cold pressing, cutting, slitting, and drying at 85 ℃ under vacuum for 12 hours to obtain a positive electrode plate; and rolling, slitting and cutting the obtained pole piece to obtain the target pole piece.
(2) Preparing a negative plate: the negative electrode active material artificial graphite, a conductive agent Super-P, a thickener sodium carboxymethyl cellulose (CMC) and a binder styrene-butadiene rubber are mixed according to the mass ratio of 96.2:2:0.8:1, mixing, adding deionized water, and obtaining negative electrode slurry under the action of a vacuum stirrer, wherein the solid content of the negative electrode slurry is 54wt%; uniformly coating the negative electrode slurry on a negative electrode current collector copper foil; and (3) drying the coated copper foil at high temperature, cold pressing, cutting and slitting, and then drying for 12 hours under the vacuum condition at 120 ℃ to obtain the negative plate.
(3) Preparation of electrolyte: in a dry argon glove box, an organic solvent (EC/DEC/emc=3/2/5, according to mass ratio), additives, lithium salt electrolyte were mixed according to the desired content. Specifically, an organic solvent is firstly added into a dry argon glove box, then an additive is added, the lithium salt electrolyte is added after dissolution and full stirring, and the electrolyte is obtained after uniform mixing.
(4) Preparation of a separation film: the polymer with the thickness of 9um is selectedEthylene separator film, which is made of PVDF slurry, inorganic particles (boehmite in flake form and Al 2 O 3 The mass ratio of (2) is 70:30 And (3) coating and drying the slurry to obtain the final isolating film, wherein the thickness of the coating is 3um, and the porosity of the membrane is 55%.
(5) Preparation of a lithium ion battery: sequentially stacking the positive plate, the isolating film and the negative plate, so that the isolating film is positioned between the positive plate and the negative plate to play a role in isolation; then winding the positive plate, the isolating film and the negative plate to obtain a bare cell, welding the tab, and placing the obtained bare cell in an aluminum-plastic film of an outer package; the electrolyte according to the embodiment of the disclosure is injected into the dried bare cell, and the target cell is obtained through the procedures of vacuum packaging, standing, formation (for example, 0.02C constant current is filled to 3.3V, and then 0.1C constant current is filled to 3.6V), shaping, capacity testing and the like.
In examples 1 to 12 and comparative examples 1 to 7, the kinds and contents of the first additive and the second additive used are shown in tables 1, 2 and 3, wherein the contents of the respective additives are weight percentages calculated based on the total mass of the electrolyte.
Next, a performance test process and test results of the lithium ion battery are described.
1. High temperature cycle test of lithium ion battery:
the lithium ion battery is placed in a constant temperature oven at 45 ℃, is charged to 4.2V at a constant current of 2.0C, is charged to a current of 0.05C at a constant voltage, is kept stand for 5min (minutes), is discharged to 3.0V at a constant current of 1C, and is kept stand for 10min, so that the lithium ion battery is used as a cycle. The discharge capacity at the initial cycle was designated as C0, and the discharge capacity at 1000 cycles of the battery was designated as C1000.
The capacity retention (%) =c1000/c0×100% after 1000 cycles of lithium ion battery at 45 ℃.
2. High temperature storage test of lithium ion battery:
before storage, the lithium ion battery is charged to 3.65V at a constant current of 0.5C, then the thickness of the lithium ion battery is tested by using a plate thickness meter to obtain the thickness L1, the constant current of 0.5C is charged to 4.2V, the constant voltage is charged to 0.05C, then the lithium ion battery is placed in a high-temperature oven at 60 ℃ for storage for 30 days, and the thickness L30 of the lithium ion battery is measured again after the lithium ion battery is cooled.
The thickness increase rate of the high-temperature storage battery cell of the lithium ion battery is = (L30-L1)/L1 is 100%.
3. DCR test of lithium ion battery:
placing the lithium ion battery in a constant temperature box at 25 ℃ for 2 hours, charging the lithium ion battery to 4.2V at a constant current of 0.5 ℃, charging the lithium ion battery to 0.05C at a constant voltage, standing for 5min, discharging the lithium ion battery to 3.0V at a constant current of 0.1C, and recording the lithium ion battery as capacity C 2 At 0.2C 2 Constant current discharge for 2.5h, recording end voltage U0,1C 2 Discharge for 1s (second), and record terminal voltage U1.
The calculation formula of the direct current internal resistance DCR of the lithium ion battery is as follows: dcr= (U0-U1)/(0.9C) 2 )。
4. And (3) cell heating experiment:
placing each group of 5 lithium ion batteries in a constant temperature box at 25 ℃, and standing for 30 minutes to enable the lithium ion batteries to reach constant temperature. Discharging to 3V at constant current of 0.5C, standing for 5min, charging the lithium ion battery to 4.2V at constant current of 0.5C, charging to 0.05C at constant voltage, standing for 5min, heating to 130 ℃ at 5 ℃/min, keeping the temperature for 60 min, observing and recording the state of the sample, photographing and recording, and performing a heating experiment without ignition or explosion.
Table 1 below shows the capacity retention after 1000 cycles of various lithium ion batteries. In various lithium ion batteries, the content of the first additive and the second additive refers to mass percentages relative to the total mass of the electrolyte. In comparative example 1, the contents of the first additive and the second additive were both 0, that is, the first additive and the second additive were not added to the electrolyte, at which time the capacity retention rate was 81%; in comparative example 2, the first additive represented by the formula I-4 was used in an amount of 0.01%, and the second additive was used in an amount of 0, at which time the capacity retention rate was 82%; in comparative example 5, the second additive represented by the formula II-7 was used in an amount of 0.01%, and the first additive was used in an amount of 0, at which time the capacity retention rate was 81%; in example 1, the first additive represented by the formula I-4 was used in an amount of 0.1%, and the second additive represented by the formula II-7 was used in an amount of 0.5%, at which time the capacity retention was 83%. The types and amounts of the first additive and the second additive and the corresponding capacity retention rates in other examples and comparative examples are shown in table 1 in the same manner, and will not be described again here.
Table 1 capacity retention of lithium ion battery
The high-temperature cycle capacity retention rate data of comparative examples 1 to 7 in table 1 show that, in the practical range, both the first additive and the second additive can form an interfacial film on the surface of the electrode material, inhibit phase transition of the positive electrode material and loss of lithium source due to polarization, and improve the high-temperature cycle retention rate. Compared with the second additive, the first additive forms an interface film which is more uniform and compact, and the circulation improving effect is more obvious. Comparison of the retention data of examples 1-12 with the retention data of comparative examples 1-7 shows that the first additive and the second additive, when present together, form an interfacial film having a synergistic effect, the redox potentials of the two being coupled, the interfacial film being rich in multi-scale inorganic components, providing a more excellent cycle improvement effect. In particular, example 3 can achieve the highest capacity retention rate as compared with other examples and comparative examples.
Table 2 below shows the DCR test results and thickness retention of various lithium ion batteries stored at 60 ℃ for 30 days. In various lithium ion batteries, the content of the first additive and the second additive refers to mass percentages relative to the total mass of the electrolyte. In comparative example 1, the contents of the first additive and the second additive were both 0, i.e., the first additive and the second additive were not added to the electrolyte, and the DCR at this time was 44mohm and the thickness increase rate was 25%; in comparative example 2, the first additive represented by formula I-4 was used in an amount of 0.01% and the second additive was used in an amount of 0, and DCR at this time was 44mohm and the thickness increase rate was 22%; in comparative example 5, the second additive represented by formula II-7 was used in an amount of 0.01% and the first additive was used in an amount of 0, and DCR at this time was 44mohm and the thickness increase rate was 24%; in example 1, the first additive represented by formula I-4 was used in an amount of 0.1%, and the second additive represented by formula II-7 was used in an amount of 0.5%, and the DCR at this time was 42mohm and the thickness increase rate was 19%. The types and amounts of the first additive and the second additive and the corresponding DCR and thickness increase rate in other examples and comparative examples are shown in table 2 in the same manner, and will not be described again here.
Table 2 DCR test results and thickness retention of lithium ion batteries
The DCR and thickness retention data of comparative examples 1 to 7 in table 2 show that both the first additive and the second additive can improve high temperature storage performance while reducing resistance in the practical range. The interface film formed by the first additive and the second additive has excellent ionic conductivity, and the interface film has excellent high-temperature electrochemical stability and mechanical modulus. Comparison of the DCR and thickness retention data of examples 1-12 with the DCR and thickness retention data of comparative examples 1-7 shows that, within the scope of implementation, the composition of the first additive and the second additive directly determine the composition and thickness of the interfacial film, and after the content of both additives is optimized, the thickness and size of the optimized interfacial film can simultaneously satisfy the inhibition of high temperature side reaction gas production, simultaneously promote lithium ion conduction more rapidly, and reduce interfacial impedance. Especially example 3, the lowest DCR and thickness increase rate can be achieved compared to other examples and comparative examples.
Table 3 below shows the results of the heating experiments for various lithium ion batteries. In various lithium ion batteries, the content of the first additive and the second additive refers to mass percentages relative to the total mass of the electrolyte. In comparative example 1, the contents of the first additive and the second additive were both 0, that is, the first additive and the second additive were not added to the electrolyte, and the passing rate of the heating experiment at this time was 0/5, that is, the group of 5 lithium ion batteries failed the heating experiment; in comparative example 2, the first additive represented by the formula I-4 was used in an amount of 0.01% and the second additive was used in an amount of 0, and the passing rate of the heating test at this time was 0/5, i.e., none of the 5 lithium ion batteries of the group passed the heating test; in comparative example 6, the second additive represented by the formula II-7 was used in an amount of 4% and the first additive was used in an amount of 0, and the pass rate of the heating test at this time was 2/5, i.e., two of the 5 lithium ion batteries of the group passed the heating test, and three failed the heating test; in example 2, the first additive represented by formula I-4 was used in an amount of 0.5% and the second additive represented by formula II-7 was used in an amount of 1%, at which time the pass rate of the heating test was 3/5, i.e., three of the 5 lithium ion batteries passed the heating test and two failed the heating test. The types and amounts of the first additive and the second additive in other examples and comparative examples and the corresponding heat test passing rates are shown in table 3 in the same manner, and will not be described again here.
Table 3 heating test results of lithium ion battery
The heating test results of comparative examples 1, 3, 4, 6 and 7 in table 3 show that the addition of a certain amount of the first additive and the second additive to the electrolyte can improve the heating test passing rate of the lithium ion battery. The heating experiment passing rate data of examples 1-12 show that the combination of the first additive and the second additive in the optimized ratio has very remarkable effect on the heating experiment passing rate improvement, and the main reason is that the interface film formed by the first additive and the second additive in the optimized ratio is more uniform, so that the overall heat generation rate is inhibited; and the components of the interface film have better high-temperature stability, and the two comprehensively improve the passing rate of the heating experiment of the lithium ion battery. In particular, examples 3 and 8, compared with other examples and comparative examples, can achieve the highest pass rate of the heating test, which is 5/5, i.e., each of the 5 lithium ion batteries of the corresponding group can pass the heating test.
[ electronic device ]
Embodiments of the present disclosure also provide an electronic device that may be any electronic device including, but not limited to, an automobile, a motorcycle, a skateboard, an airplane, a passenger car, a motor, a backup power source, a household large-sized battery, a lithium ion capacitor, a computer, a cell phone, an electronic book, a facsimile machine, a copier, a flash lamp, a television, a VR, an AR, and the like. Note that the electrochemical device of the embodiments of the present disclosure is applicable to, in addition to the above-described electronic devices as examples, electronic devices such as energy storage power stations, marine vehicles, air vehicles, and the like. The air vehicle comprises an air vehicle within the atmosphere and an air vehicle outside the atmosphere.
The electronic device of the embodiments of the present disclosure may include the electrochemical device as described above.
The foregoing description of the embodiments of the present disclosure has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvement in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (10)
1. An electrolyte comprising a compound represented by formula I,
in the case of the formula I,
r1, R2 and R3 are each independently selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a substituted or unsubstituted C2-C4 alkenylene group, and a heteroatom, wherein the heteroatom includes at least one of an O atom, an S atom, and an N atom, and when substituted, the substituent includes at least one of an F atom, a sulfonyl group, a cyano group, and an alkoxy group;
r4 is selected from any one of substituted or unsubstituted C1-C4 alkyl, N atom, P atom and B atom, wherein when substituted, the substituent comprises at least one of C2-C4 alkenyl, C2-C4 alkynyl, F atom and derivatives thereof, sulfonyl, cyano and alkoxy; and
X1 is selected from any one of P atom, B atom and P or B containing group.
2. The electrolyte according to claim 1, wherein the compound represented by formula I includes at least one of compounds represented by formulas I-1 to I-8:
3. the electrolyte according to claim 1, wherein the mass percentage of the compound represented by formula I is 0.1% -2% based on the total mass of the electrolyte.
4. The electrolyte according to claim 1, further comprising a compound represented by formula II,
in formula II, R5 is selected from any one of a substituted or unsubstituted C1-C4 alkyl group, a C2-C4 alkenyl group, a C2-C4 alkynyl group, an O atom, an S atom and an N atom, wherein when substituted, the substituent includes at least one of an F atom, a sulfonyl group and a cyano group.
5. The electrolyte according to claim 4, wherein the compound represented by formula II includes at least one of compounds represented by formulas II-1 to II-8:
6. the electrolyte according to claim 4, wherein the total mass percentage of both the compound represented by formula I and the compound represented by formula II is 0.01% -20% based on the total mass of the electrolyte.
7. The electrolyte according to claim 6, wherein the mass percentage of the compound represented by formula I is 0.1% -2% based on the total mass of the electrolyte.
8. The electrolyte according to claim 6, wherein the mass percentage of the compound represented by formula II is 0.1% -5% based on the total mass of the electrolyte.
9. An electrochemical device comprising a positive electrode sheet, a negative electrode sheet, a separator, and the electrolyte according to any one of claims 1 to 8.
10. An electronic device comprising the electrochemical device according to claim 9.
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