CN112467210B - Lithium ion battery and preparation method thereof - Google Patents
Lithium ion battery and preparation method thereof Download PDFInfo
- Publication number
- CN112467210B CN112467210B CN201910864602.4A CN201910864602A CN112467210B CN 112467210 B CN112467210 B CN 112467210B CN 201910864602 A CN201910864602 A CN 201910864602A CN 112467210 B CN112467210 B CN 112467210B
- Authority
- CN
- China
- Prior art keywords
- lithium
- ion battery
- lithium ion
- active material
- compound
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The invention provides a lithium ion battery containing a nonaqueous electrolyte and a preparation method thereof. The lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the positive electrode comprises a positive active material, a binder and a conductive agent, the negative electrode comprises a negative active material and a conductive agent, the electrolyte comprises a non-aqueous organic solvent, a conductive lithium salt and an additive, and the additive comprises a phenylsilane compound and a lithium salt compound; the phenyl silane compound and the lithium salt compound are combined for use, wherein the phenyl silane compound can be better complexed with the anode to form a similar protective layer, so that the anode structure is more stable, and the side reaction decomposition of the electrolyte is prevented from being catalyzed by the dissolution of metal ions; the lithium salt type compound can form more SEI films with inorganic layers and better toughness on the surface of the negative electrode, and lithium ions can migrate efficiently.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery and a preparation method thereof.
Background
Lithium ion batteries have excellent electrochemical properties such as high specific energy, long service life, high operating voltage, and no memory effect, and have been widely used in the consumer electronics field. With the rapid development of electronic technology, in order to meet the increasing demand of people on products, the development of lithium ion batteries with high and low temperature, longer cycle life and better safety is urgently needed.
The electrolyte is one of main materials of the lithium ion battery, and plays a role in transmitting Li < + > in the lithium ion battery. Therefore, research and development of an electrolyte are important for a lithium ion battery, but an electrolyte having excellent overall performance and high and low temperature performance is not easily developed. At present, the use of additives in electrolytes is a highly effective weapon to solve the above problems. However, it is often difficult to simultaneously achieve high and low temperature performance with current electrolyte additives.
Disclosure of Invention
The invention aims to solve the problem that the existing electrolyte additive is not ideal in both high and low temperature performance, and provides a lithium ion battery, which contains an electrolyte, wherein the electrolyte can improve the cycle life of the lithium ion battery and simultaneously has both low temperature performance and long service life.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, wherein the positive electrode comprises a positive electrode active material, a binder and a conductive agent, the negative electrode comprises a negative electrode active material and a conductive agent, the electrolyte comprises a non-aqueous organic solvent, a conductive lithium salt and an additive, and the additive comprises a phenylsilane compound and a lithium salt compound;
wherein the mass ratio of the phenyl silane compound to the sum of the positive electrode active material and the conductive agent is more than 0 and less than or equal to 0.06; the mass ratio of the lithium salt type compound to the sum of the negative electrode active material and the conductive agent is more than 0 and less than or equal to 0.05.
Further, the mass ratio of the phenylsilane compound to the sum of the positive electrode active material and the conductive agent is 0.005 to 0.06, for example, 0.05, 0.04, 0.03, 0.02, 0.01, 0.005; the mass ratio of the lithium salt type compound to the sum of the negative electrode active material and the conductive agent is 0.005 or more and 0.05 or less, for example, 0.04, 0.03, 0.02, 0.01, 0.005 or less.
Further, the mass ratio of the positive electrode active material and the conductive agent is well known in the art.
Further, the mass ratio of the negative electrode active material and the conductive agent is well known in the art.
Further, the phenylsilane compound has a general structural formula shown in a formula (I):
wherein R is 1 、R 2 Identical or different, each independently selected from halogen, unsubstituted or optionally substituted by one, two or more R a Substituted of the following groups: c 1-12 Alkyl radical, C 2-12 Alkenyl radical, C 2-12 Alkynyl, C 6-20 An aryl group; each R a Identical or different, independently of one another, from halogen, C 1-12 An alkyl group.
Further, R 1 、R 2 Same or different, each independently selected from F, C 1-6 Alkyl radical, C 2-6 Alkenyl, phenyl, naphthyl.
The term "C 1-12 Alkyl is understood to preferably mean a straight-chain or branched, saturated monovalent hydrocarbon radical having from 1 to 12 carbon atoms, preferably C 1-10 An alkyl group. "C 1-10 Alkyl "is understood to preferably mean a straight-chain or branched, saturated monovalent hydrocarbon radical having 1,2,3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. The alkyl group is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a 2-methylbutyl group, a 1-ethylpropyl group, a 1, 2-dimethylpropyl group, a neopentyl group, a 1, 1-dimethylpropyl group, a 4-methylpentyl group, a 3-methylpentyl group, a 2-ethylbutyl group, a 1-ethylbutyl group, a 3, 3-dimethylbutyl group, a 2, 2-dimethylbutyl group, a 1, 1-dimethylbutyl group, a 2, 3-dimethylbutyl group, a 1, 3-dimethylbutyl group or a 1, 2-dimethylbutyl group, or the like, or isomers thereof. In particular, the radicals have 1,2,3, 4, 5, 6 carbon atoms ("C) 1-6 Alkyl groups) such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, more particularly groups having 1,2 or 3 carbon atoms ("C) 1-3 Alkyl radicals), e.g. methyl, ethylN-propyl or isopropyl.
The term "C 2-12 Alkenyl "is understood to preferably mean a straight-chain or branched monovalent hydrocarbon radical comprising one or more double bonds and having from 2 to 12 carbon atoms, preferably" C 2-10 Alkenyl ". "C 2-10 Alkenyl "is understood to preferably mean a straight-chain or branched, monovalent hydrocarbon radical which contains one or more double bonds and has 2,3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms (" C 2-3 Alkenyl "), it being understood that in the case where the alkenyl group comprises more than one double bond, the double bonds may be separated from each other or conjugated. The alkenyl group is, for example, vinyl, allyl, (E) -2-methylvinyl, (Z) -2-methylvinyl, (E) -but-2-enyl, (Z) -but-2-enyl, (E) -but-1-enyl, (Z) -but-1-enyl, pent-4-enyl, (E) -pent-3-enyl, (Z) -pent-3-enyl, (E) -pent-2-enyl, (Z) -pent-2-enyl, (E) -pent-1-enyl, (Z) -pent-1-enyl, hex-5-enyl, (E) -hex-4-enyl, (Z) -hex-4-enyl, m-n-2-enyl, m-n-1-enyl, m-n-E-4-enyl, m-n-2-enyl, m-n-enyl, m-E-4-enyl, m-2-enyl, m-pent-1-enyl, m-2-methyl-enyl, m-2-methylvinyl, m-2-methyl-2-methylvinyl, m-but-2-enyl, (E) -hex-3-enyl, (Z) -hex-3-enyl, (E) -hex-2-enyl, (Z) -hex-2-enyl, (E) -hex-1-enyl, (Z) -hex-1-enyl, isopropenyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl, 2-methylprop-1-enyl, (E) -1-methylprop-1-enyl, (Z) -1-methylprop-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E) -2-methylbut-2-enyl, (Z) -2-methylbut-2-enyl, (E) -1-methylbut-2-enyl, (Z) -1-methylbut-2-enyl, (E) -3-methylbut-1-enyl, (Z) -3-methylbut-1-enyl, (E) -2-methylbut-1-enyl, (Z) -2-methylbut-1-enyl, (E) -1-methylbut-1-enyl, (Z) -1-methylbut-1-enyl, 1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, m-methylbut-2-enyl, m-methylbut-1-enyl, m-methylbut-2-enyl, m-methylbut-1-ylprop-1-enyl, m-methylbut-2-enyl, m-methylbut-1-enyl, m, 1-propylvinyl group and 1-isopropylvinyl group.
The term "C 2-12 Alkynyl "is understood to mean a straight-chain or branched monovalent hydrocarbon radical comprising one or more triple bonds and having from 2 to 12 carbon atoms, preferably" C 2 -C 10 Alkynyl ". The term "C 2 -C 10 Alkynyl "is understood as preferably meaning a straight-chain or branched, monovalent hydrocarbon radical which contains one or more triple bonds and has a structure of 2,3, 4, 5,6. 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms ("C) 2 -C 3 -alkynyl "). The alkynyl group is, for example, ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 1-methylprop-2-ynyl, 2-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, prop-2-ynyl, but-3-methylbut-1-ynyl, and so-1-ethylprop-2-ynyl, 3-methylpent-4-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-3-ynyl, 1-methylpent-3-ynyl, 4-methylpent-2-ynyl, 1-methylpent-2-ynyl, 4-methylpent-1-ynyl, 3-methylpent-1-ynyl, 2-ethylbut-3-ynyl, 1-ethylbut-2-ynyl, 1-propylprop-2-ynyl, 1-isopropylprop-2-ynyl, 2-dimethylbut-3-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-1-ynyl, 3-methylpent-1-ynyl, 2-ynyl, 2-dimethylbut-3-ynyl, 2-methylpent-2-ynyl, 4-methylpent-alkynyl, 4-ynyl, 2-methylpent-3-ynyl, 3-methylpent-ynyl, 3-1-methylpent-1-ynyl, 3-1-methylpent-ynyl, 3-ynyl, 2-methylpent-1-ynyl, 3-1-methylpent-1-ynyl, methyl-1-methylpent-1-ynyl, 2-1-methylpent-1-ynyl, 2-1-methylpent-1-ynyl, 2-1-methylpent-1-methylpent-1-ynyl, 2-1-ynyl, 2-1-2-1-2-ynyl, 2-alkynyl, 2-butynyl, 2-butynyl, 2, 1, 1-dimethylbut-3-ynyl, 1-dimethylbut-2-ynyl or 3, 3-dimethylbut-1-ynyl. In particular, the alkynyl group is ethynyl, prop-1-ynyl or prop-2-ynyl.
The term "C 6-20 Aryl "is understood to preferably mean a monocyclic, bicyclic or tricyclic hydrocarbon ring of monovalent or partial aromaticity having 6 to 20 carbon atoms, preferably" C 6-14 Aryl ". The term "C 6-14 Aryl "is to be understood as preferably meaning a mono-, bi-or tricyclic hydrocarbon ring having a monovalent or partially aromatic character with 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms (" C 6-14 Aryl group "), in particular a ring having 6 carbon atoms (" C 6 Aryl "), such as phenyl; or biphenyl, or is a ring having 9 carbon atoms ("C 9 Aryl), such as indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 Aryl radicals), such as tetralinyl, dihydronaphthyl or naphthyl, or rings having 13 carbon atoms ("C 13 Aryl radicals), such as the fluorenyl radical, or a ring having 14 carbon atoms ("C) 14 Aryl), such as anthracyl.
Further, the phenylsilane compounds are selected from at least one of the compounds shown in the following formulas (II) to (VII):
further, the lithium salt type compound is selected from one or a mixture of more of lithium difluorophosphate, lithium difluorosulfimide, lithium difluorobis (oxalato) phosphate, lithium tetrafluorooxalato phosphate, lithium difluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide and lithium bis (oxalato borate).
Further, the non-aqueous organic solvent is selected from one or a combination of a plurality of carbonic esters, carboxylic esters and fluoroethers, wherein the carbonic ester is selected from one or a combination of a plurality of carbonic esters such as ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and methyl propyl carbonate; the carboxylic ester is selected from one or more of ethyl propionate and propyl propionate; the fluoroether is selected from 1,1,2, 3-tetrafluoroethyl-2, 2,3, 3-tetrafluoropropyl ether.
Furthermore, the lithium salt is selected from lithium hexafluorophosphate, and the dosage of the lithium salt accounts for 10-20% of the total mass of the nonaqueous electrolyte.
Further, the positive electrode active material is selected from LiCoO 2 、LiNiO 2 、LiMn 2 O 4 、LiFePO 4 、Li x Ni y M 1-y O 2 Wherein x is more than or equal to 0.9 and less than or equal to 1.2, and y is more than or equal to 0.5<1, M is selected from one or more of Co, Mn, Al, Mg, Ti, Zr, Fe, Cr, Mo, Cu and Ca.
Further, the negative active material is graphite or a graphite composite material containing 1-12 wt.% SiOx/C or Si/C, wherein 2> x > 0.
Further, the conductive agent is selected from conductive agents known in the art for preparing a positive electrode or a negative electrode, for example, from acetylene black, carbon nanotubes, and the like.
Further, the separator is a separator known in the art, such as a polyethylene separator, a polypropylene separator, and the like.
The invention also provides a preparation method of the lithium ion battery containing the nonaqueous electrolyte, which comprises the following steps:
(1) preparing a positive plate and a negative plate, wherein the positive plate contains a positive active substance, and the negative plate contains a negative active substance;
(2) mixing a non-aqueous organic solvent, a conductive lithium salt and an additive, and ensuring that the mass ratio of the phenyl silane compound to the sum of the positive active material and the conductive agent is less than or equal to 0.06; the mass ratio of the lithium salt type compound to the sum of the mass of the negative electrode active material and the mass of the conductive agent is less than or equal to 0.05, and an electrolyte is prepared;
(3) winding the positive plate, the diaphragm and the negative plate to obtain a naked battery cell without liquid injection; and (3) placing the bare cell in an outer packaging foil, injecting the electrolyte in the step (2) into the dried bare cell, and preparing to obtain the lithium ion battery.
Exemplarily, the method specifically comprises the following steps:
1) preparing a positive plate:
ternary material (such as LiNi) of positive electrode active material 0.5 Co 0.3 Mn 0.2 O 2 ) Mixing polyvinylidene fluoride (PVDF) serving as a binder and acetylene black serving as a conductive agent according to a weight ratio of 96.5:2:1.5, adding N-methylpyrrolidone (NMP), and stirring under the action of a vacuum stirrer until a mixed system becomes uniform and flowable anode slurry; uniformly coating the positive electrode slurry on an aluminum foil with the thickness of 9-12 mu m; drying the coated aluminum foil in an oven at the temperature of 100-130 ℃ for 4-10h, and then rolling and slitting to obtain a required positive plate;
2) preparing a negative plate:
mixing a negative electrode active material graphite, a thickening agent sodium carboxymethyl cellulose (CMC), a binder styrene butadiene rubber and a conductive agent acetylene black according to a weight ratio of 96.4:1:1:1.6, adding deionized water, and obtaining negative electrode slurry under the action of a vacuum stirrer; uniformly coating the negative electrode slurry on a copper foil with the thickness of 6-9 mu m; airing the copper foil at room temperature, transferring the copper foil to a 75-100 ℃ oven for drying for 6-12h, and then carrying out cold pressing and slitting to obtain a negative plate;
3) preparing an electrolyte:
uniformly mixing ethylene carbonate, propylene carbonate, diethyl carbonate and n-propyl propionate according to the mass ratio of 20:20:25:35 in a glove box filled with argon and having qualified water oxygen content, and quickly adding 1mol/L of fully dried lithium hexafluorophosphate (LiPF) 6 ) Phenyl silane compounds and lithium salt compounds, and the mass ratio of the phenyl silane compounds to the sum of the positive active material and the conductive agent is less than or equal to 0.06; the mass ratio of the lithium salt type compound to the sum of the mass of the negative electrode active material and the mass of the conductive agent is less than or equal to 0.05, and an electrolyte is prepared;
4) preparing a diaphragm:
selecting a polyethylene diaphragm with the thickness of 7-9 mu m;
5) preparation of lithium ion battery
Winding the prepared positive plate, the diaphragm and the prepared negative plate to obtain a naked battery cell without liquid injection; placing the bare cell in an outer packaging foil, injecting the prepared electrolyte into the dried bare cell, and performing vacuum packaging, standing, formation, shaping, sorting and other processes to obtain the required lithium ion battery.
Furthermore, the charge cut-off voltage of the lithium ion battery is more than or equal to 4.4V.
Has the beneficial effects that:
the invention provides a lithium ion battery containing a nonaqueous electrolyte and a preparation method thereof. The lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the positive electrode comprises a positive active material, a binder and a conductive agent, the negative electrode comprises a negative active material and a conductive agent, the electrolyte comprises a non-aqueous organic solvent, a conductive lithium salt and an additive, and the additive comprises a phenylsilane compound and a lithium salt compound; the phenyl silane compound and the lithium salt compound are combined for use, wherein the phenyl silane compound can be better complexed with the anode to form a similar protective layer, so that the anode structure is more stable, and the side reaction decomposition of the electrolyte is prevented from being catalyzed by the dissolution of metal ions; the lithium salt type compound can form more SEI films with better inorganic layer toughness on the surface of the negative electrode, so that lithium ions can be transferred efficiently. In conclusion, the two additives are comprehensively protected, the mass ratios of the two additives to the positive and negative electrode active substances and the conductive agent are respectively limited, and a proper amount of additive can form a sufficient amount of firm positive and negative electrode interface film with high lithium ion conductivity on the surfaces of the positive and negative electrode active substances and the surface of the conductive agent, so that the low-temperature performance and the cycle life of the battery are improved.
Detailed Description
The preparation method of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.
Comparative examples 1 to 3 and examples 1 to 10
The lithium ion batteries of comparative examples 1 to 3 and examples 1 to 10 were each prepared according to the following preparation method, except for the selection and addition of additives, and the specific differences are shown in tables 1 and 2.
(1) Preparation of positive plate
LiNi as positive electrode active material 0.5 Co 0.3 Mn 0.2 O 2 Mixing polyvinylidene fluoride (PVDF) serving as a binder and acetylene black serving as a conductive agent according to a weight ratio of 96.5:2:1.5, adding N-methylpyrrolidone (NMP), and stirring under the action of a vacuum stirrer until a mixed system becomes uniform and flowable anode slurry; uniformly coating the positive electrode slurry on an aluminum foil with the thickness of 9-12 mu m; baking the coated aluminum foil in 5 sections of baking ovens with different temperature gradients, drying the aluminum foil in a baking oven at 120 ℃ for 8 hours, and rolling and cutting to obtain the required positive plate.
(2) Preparation of negative plate
Mixing a negative active material graphite, a thickening agent sodium carboxymethyl cellulose (CMC), a binder styrene butadiene rubber and a conductive agent acetylene black according to a weight ratio of 96.4:1:1:1.6, adding deionized water, and obtaining negative slurry under the action of a vacuum stirrer; uniformly coating the negative electrode slurry on a copper foil with the thickness of 6-9 mu m; and (3) airing the copper foil at room temperature, transferring the copper foil to an oven at 80 ℃ for drying for 8h, and then carrying out cold pressing and slitting to obtain the negative plate.
(3) Preparation of electrolyte
Uniformly mixing ethylene carbonate, propylene carbonate, diethyl carbonate and n-propyl propionate according to the mass ratio of 20:20:25:35 in a glove box filled with argon and qualified in water oxygen content (the solvent needs to be normalized), and quickly adding 1mol/L of fully dried lithium hexafluorophosphate (LiPF) 6 ) And additives (specific amounts and selections are shown in tables 1 and 2) to obtain an electrolyte.
(4) Preparation of the separator
Selecting a polyethylene diaphragm with the thickness of 7-9 mu m.
(5) Preparation of lithium ion battery
Winding the prepared positive plate, the diaphragm and the prepared negative plate to obtain a naked battery cell without liquid injection; placing the bare cell in an outer packaging foil, injecting the prepared electrolyte into the dried bare cell, and performing vacuum packaging, standing, formation, shaping, sorting and other processes to obtain the required lithium ion battery.
Table 1 compositions of lithium ion batteries prepared in comparative examples 1 to 3
Table 2 compositions of lithium ion batteries prepared in examples 1-10
The lithium ion batteries in the examples and comparative examples were tested for high temperature cycle and low temperature discharge performance under the following specific test conditions:
high-temperature cycle test: standing at 45 deg.C, performing charge-discharge cycle with 1C current in 2.8-4.2V charge-discharge voltage interval, recording initial capacity as Q, and selecting capacity as Q for cycle of 500 weeks 1 The capacity retention rate of the battery at high temperature cycle for 500 weeks was calculated by the following formula:
capacity retention ratio (%) - (Q) 1 /Q×100。
And (3) low-temperature discharge test: the cell was charged and discharged 3 times at 1C rate at room temperature, then charged to full charge at 1C rate, and the 1C capacity Q was recorded 0 . Laying the battery in a full-charge state at-20 ℃ for 4h, discharging to 3V at 0.4C rate, and recording discharge capacity Q 2 Calculating the low-temperature discharge capacity retention rate, recording the result, and calculating the low-temperature discharge capacity retention rate of the battery according to the following formula:
capacity retention (%) ═ Q 2 /Q×100。
TABLE 3 test results of comparative examples 1-3 and examples 1-10
The data show that the phenyl silane compound and the lithium salt compound have obvious beneficial effects on high-temperature circulation and low-temperature discharge of the lithium ion battery, and the phenyl silane compound and the lithium salt compound are mixed and added into the electrolyte, so that the lithium ion battery has outstanding advantages, and the high-temperature and low-temperature electrical properties of the battery are mainly improved. The examples 1 to 10 are obviously superior to the comparative examples, so that the battery prepared by the electrolyte has extremely high durability and market value and social benefit.
The reason why the cell performance is deteriorated when the additive is not added or the additive amount exceeds the ratio in comparative examples 1 to 3 is that the resistance is too large due to excessive side reactions of the additive, and the cycle performance of the lithium ion battery using the electrolyte according to the present invention is significantly improved, and the low temperature performance of the battery is also significantly improved.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made without departing from the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (9)
1. A lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, wherein the positive electrode comprises a positive electrode active material, a binder and a conductive agent, the negative electrode comprises a negative electrode active material and a conductive agent, the electrolyte comprises a non-aqueous organic solvent, a conductive lithium salt and an additive, and the additive comprises a phenylsilane compound and a lithium salt compound;
wherein the mass ratio of the phenylsilane compound to the sum of the positive electrode active material and the conductive agent is more than 0 and less than or equal to 0.06; the mass ratio of the lithium salt type compound to the sum of the negative electrode active material and the conductive agent is more than 0 and less than or equal to 0.05;
the phenylsilane compound has a general structural formula shown in a formula (I):
wherein R is 1 、R 2 Identical or different, each independently selected from halogen, unsubstituted or optionally substituted by one, two or more R a Substituted of the following groups: c 1-12 Alkyl radical, C 2-12 Alkenyl radical, C 2-12 Alkynyl, C 6-20 An aryl group; each R a Identical or different, independently of one another, from halogen, C 1-12 An alkyl group;
the lithium salt type compound is selected from one or a mixture of more of lithium difluorophosphate, lithium difluorosulfonimide, lithium difluorobis (oxalato) phosphate, lithium tetrafluoro (oxalato) phosphate, lithium difluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide and lithium bis (oxalato) borate.
2. The lithium ion battery according to claim 1, wherein the mass ratio of the phenylsilane-based compound to the sum of the positive electrode active material and the conductive agent is 0.005 or more and 0.06 or less; the mass ratio of the lithium salt type compound to the sum of the negative electrode active material and the conductive agent is not less than 0.005 and not more than 0.05.
3. The lithium ion battery of claim 1, wherein R 1 、R 2 Same or different, each independently selected from F, C 1-6 Alkyl radical, C 2-6 Alkenyl, phenyl, naphthyl.
4. The lithium ion battery according to claim 3, wherein the phenylsilane compound is at least one selected from the group consisting of compounds represented by the following formulae (II) to (VII):
5. the lithium ion battery according to any one of claims 1 to 4, wherein the non-aqueous organic solvent is selected from one or more of carbonate, carboxylic ester and fluoroether, wherein the carbonate is selected from one or more of ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and propyl methyl carbonate; the carboxylic ester is selected from one or more of ethyl propionate and propyl propionate; the fluoroether is selected from 1,1,2, 3-tetrafluoroethyl-2, 2,3, 3-tetrafluoropropyl ether.
6. The lithium ion battery according to any one of claims 1 to 4, wherein the lithium salt is selected from lithium hexafluorophosphate in an amount of 10 to 20% by mass based on the total mass of the nonaqueous electrolytic solution.
7. The lithium ion battery of any of claims 1-4, wherein the positive electrode active material is selected from LiCoO 2 、LiNiO 2 、LiMn 2 O 4 、LiFePO 4 、Li x Ni y M 1-y O 2 Wherein x is more than or equal to 0.9 and less than or equal to 1.2, and y is more than or equal to 0.5<1, M is selected from one or more of Co, Mn, Al, Mg, Ti, Zr, Fe, Cr, Mo, Cu and Ca.
8. The lithium ion battery of any of claims 1-4, wherein the negative active material is graphite, a graphite composite with 1-12 wt.% SiOx/C, or a graphite composite with 1-12 wt.% Si/C, wherein 2> x > 0.
9. The lithium ion battery according to any one of claims 1 to 4, wherein the charge cut-off voltage of the lithium ion battery is not less than 4.4V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910864602.4A CN112467210B (en) | 2019-09-09 | 2019-09-09 | Lithium ion battery and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910864602.4A CN112467210B (en) | 2019-09-09 | 2019-09-09 | Lithium ion battery and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112467210A CN112467210A (en) | 2021-03-09 |
| CN112467210B true CN112467210B (en) | 2022-08-30 |
Family
ID=74807610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910864602.4A Active CN112467210B (en) | 2019-09-09 | 2019-09-09 | Lithium ion battery and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112467210B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007123098A (en) * | 2005-10-28 | 2007-05-17 | Sony Corp | Battery |
| CN108376765A (en) * | 2017-01-31 | 2018-08-07 | 三星电子株式会社 | It include the lithium secondary battery of electrolyte for including single fluorosilane compounds |
| WO2019031508A1 (en) * | 2017-08-10 | 2019-02-14 | 三菱ケミカル株式会社 | Nonaqueous electrolyte secondary battery |
-
2019
- 2019-09-09 CN CN201910864602.4A patent/CN112467210B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007123098A (en) * | 2005-10-28 | 2007-05-17 | Sony Corp | Battery |
| CN108376765A (en) * | 2017-01-31 | 2018-08-07 | 三星电子株式会社 | It include the lithium secondary battery of electrolyte for including single fluorosilane compounds |
| WO2019031508A1 (en) * | 2017-08-10 | 2019-02-14 | 三菱ケミカル株式会社 | Nonaqueous electrolyte secondary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112467210A (en) | 2021-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112467219B (en) | Electrolyte and lithium ion battery comprising same | |
| CN111916824B (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery using same | |
| JP3558007B2 (en) | Non-aqueous electrolyte and lithium secondary battery using the same | |
| CN107871889B (en) | Electrolyte solution and secondary battery | |
| CN110970621B (en) | Lithium ion battery | |
| CN111916825B (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery using same | |
| CN111916823A (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery using same | |
| JP4092631B2 (en) | Nonaqueous electrolyte secondary battery | |
| KR20150036216A (en) | Non-aqueous electrolyte secondary battery | |
| CN113013488A (en) | Electrolyte and lithium ion battery comprising same | |
| CN108878975B (en) | Electrolyte and secondary battery including the same | |
| CN114497737B (en) | Nonaqueous electrolyte and lithium ion battery containing same | |
| CN112467208A (en) | Silicon-carbon lithium ion battery containing non-aqueous electrolyte and preparation method and application thereof | |
| CN112467210B (en) | Lithium ion battery and preparation method thereof | |
| CN112467206A (en) | Lithium ion battery containing non-aqueous electrolyte | |
| CN112467204A (en) | Lithium ion battery containing lithium ion battery electrolyte | |
| CN112751085A (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery comprising same | |
| TW201943141A (en) | Additive for nonaqueous electrolyte solutions, nonaqueous electrolyte solution, and electricity storage device | |
| CN113013487A (en) | Electrolyte and lithium ion battery comprising same | |
| CN113013489B (en) | Electrolyte and lithium ion battery comprising same | |
| CN114122521B (en) | Nonaqueous electrolyte for lithium ion battery and lithium ion battery comprising same | |
| JP6792798B2 (en) | Manufacturing method of lithium ion secondary battery | |
| CN112803069A (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery comprising same | |
| CN112751084A (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery comprising same | |
| CN114024033A (en) | Non-aqueous electrolyte for lithium ion battery and lithium ion battery comprising same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |