CN111640977B - High-power electrolyte and lithium ion battery containing same - Google Patents
High-power electrolyte and lithium ion battery containing same Download PDFInfo
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- CN111640977B CN111640977B CN202010530963.8A CN202010530963A CN111640977B CN 111640977 B CN111640977 B CN 111640977B CN 202010530963 A CN202010530963 A CN 202010530963A CN 111640977 B CN111640977 B CN 111640977B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
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Abstract
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a high-power electrolyte and a lithium ion battery containing the same. The invention adopts the lithium iron phosphate anode material with better power performance, and simultaneously uses the solvent with high lithium ion mobility, the additive combination and the lithium salt to improve the power performance of the electrolyte. The electrolyte additive can be used for protecting the film with higher performance strength on the surface of the anode and the cathode so as to improve the high-temperature performance of the battery. Meanwhile, the lithium salt with higher decomposition temperature is used, so that the safety performance of the lithium ion battery is improved.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a high-power electrolyte and a lithium ion battery containing the same.
Background
In recent years, the automobile industry in China is rapidly developed, and the automobile conservation quantity in China is continuously improved. In the face of increasingly serious energy and environmental crisis, the country has come out a plurality of laws and regulations for energy conservation and emission reduction of automobiles. The 48V hybrid power system for the automobile can realize the functions of sliding start and stop, kinetic energy recovery, auxiliary acceleration and the like, and the fuel saving rate is 14% -17%.
However, compared with a pure electric lithium ion battery, a start-stop lithium ion battery has higher requirements on indexes of high-low temperature performance, power performance and cycle life and consideration of all performances. The positive electrode and the electrolyte are used as main components of the lithium ion battery, and the design of the positive electrode and the electrolyte is a main factor for preventing the performance of the high-power lithium ion battery from being started and stopped. Therefore, there is a need to develop electrolyte and positive electrode material combinations that meet high power discharge and high temperature performance, which would be of great significance for the development of applications for start-stop high power batteries.
Disclosure of Invention
The invention provides a high-power electrolyte with high-low temperature performance, and simultaneously provides a high-power lithium ion battery using the electrolyte, which aims to solve the problems that the current lithium ion battery is low in power density and difficult to consider high-low temperature performance, and the safety performance of the lithium ion battery is greatly improved.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
an electrolyte comprising a conductive lithium salt, an additive, and a solvent; wherein the additive comprises lithium difluorophosphate, vinyl sulfate, vinylene carbonate and boron-phosphorus lithium oxalate; the solvent comprises ethyl 3-methoxypropionate.
According to the present invention, the solvent further includes at least one of a cyclic carbonate, a linear carbonate and a linear carboxylate.
Wherein the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate and propylene carbonate.
Wherein the linear carbonate is at least one selected from dimethyl carbonate, diethyl carbonate and methylethyl carbonate.
Wherein the linear carboxylic acid ester is selected from at least one of ethyl propionate, propyl propionate and propyl acetate.
According to the invention, the viscosity of the 3-methoxy ethyl propionate is higher than that of the cyclic carbonate, the linear carbonate and the linear carboxylate, but the number of polar functional groups in the molecular structure is more, when the 3-methoxy ethyl propionate is used as an electrolyte solvent, the 3-methoxy ethyl propionate can form a solvated structure with lithium ions in the electrolyte, and the solvated structure can jump to move the lithium ions in the electrolyte, so that the migration rate of the lithium ions in the electrolyte can be quickly improved, the purpose of quickly moving the lithium ions between the anode and the cathode of the electrolyte is realized, and the power density of a lithium ion battery is improved. The solvated structure mechanism of action is as follows:
according to the invention, the addition amount of the 3-methoxy ethyl propionate accounts for 10% -50% of the total mass of the electrolyte, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50%.
According to the invention, the boron-phosphorus lithium oxalate is at least one selected from compounds shown in the following structural formula:
wherein R is 1 -R 8 Identical or different, independently of one another, from H, F, halogen-substituted C 1-6 Alkyl (e.g. CF 3 -)。
Illustratively, the boron-phosphorus lithium oxalate is at least one selected from the compounds shown in the following structural formulas:
according to the invention, the addition amount of the boron-phosphorus type lithium oxalate accounts for 0.1% -4% of the total mass of the electrolyte, such as 0.1% -2%, such as 0.1% -1%, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%.
According to the invention, the vinyl sulfate is added in an amount of 0.1% -5% by weight of the total electrolyte, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.4%, 4.5%, 4.8%, 5%.
According to the invention, the lithium difluorophosphate is added in an amount of 0.1% -2% of the total mass of the electrolyte, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, 2%.
According to the invention, the ethylene carbonate is added in an amount of 0.1% -3% of the total mass of the electrolyte, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8%, 3%.
The additive of the invention is added with the vinyl sulfate, the lithium difluorophosphate, the vinylene carbonate and the boron-phosphorus lithium oxalate at the same time, and the four components can form a novel high-conductivity ion protection film with low impedance on the surfaces of the anode and the cathode, because the formed components are mostly inorganic lithium salt compounds, and lithium ions in the electrolyte can be quickly migrated into the electrode active material through the replacement of lithium ions in the compounds, thereby improving the power density of the lithium ion battery. In addition, the obtained novel high-conductivity ion protective film with low impedance is very complete, can completely prevent the electrolyte from directly contacting with the electrode active material, prevents the electrolyte component from generating side reaction with the electrode active material, reduces the consumption of the electrolyte component in the use of the lithium ion battery, and further improves the cycle performance of the lithium ion battery.
According to the invention, the conductive lithium salt is selected from lithium difluorosulfonimide and lithium hexafluorophosphate.
According to the invention, the addition amount of the conductive lithium salt accounts for 14% -20% of the total mass of the electrolyte, such as 14%, 15%, 16%, 17%, 18%, 19% and 20%.
According to the invention, the addition amount of the lithium bis (fluorosulfonate) is 4% -17% of the total mass of the electrolyte, such as 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%.
The invention can obviously improve the high-temperature performance and the safety performance of the electrolyte by using the lithium bis (fluorosulfonate), and the lithium bis (fluorosulfonate) has a larger radius as the anion of the lithium bis (fluorosulfonate) has small acting force with the cation lithium ion, so that the migration speed of the lithium ion can be improved, and the safety of the lithium ion is further improved. Decomposition temperature of lithium bis-fluorosulfonate>200 ℃ far higher than LiPF 6 And the safety performance of lithium ions can be improved.
According to the invention, the lithium hexafluorophosphate is added in an amount of 3% -16% of the total mass of the electrolyte, such as 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%.
The invention also provides a lithium ion battery, which comprises the electrolyte.
According to the invention, the lithium ion battery further comprises a positive electrode, a negative electrode and a diaphragm.
According to the invention, the positive electrode comprises a positive electrode active material layer and a positive electrode current collector, wherein the positive electrode active material layer is arranged on one side or two side surfaces of the positive electrode current collector, and comprises a positive electrode active material, a conductive agent and a binder, wherein the positive electrode active material is lithium iron phosphate.
According to the invention, the chemical formula of the lithium iron phosphate is denoted as LiFePO 4 。
According to the invention, the material of the positive electrode current collector can be at least one of aluminum foil and nickel foil.
According to the present invention, the conductive agent may be at least one selected from carbon black, acetylene black, graphene, ketjen black, carbon fiber, and carbon nanotube.
According to the present invention, the binder may be at least one selected from polytetrafluoroethylene, polyvinylidene fluoride (PVDF), polyvinyl fluoride, polyethylene, polypropylene, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, an ethylene oxide-containing polymer, polyvinylpyrrolidone, polyurethane.
According to the invention, the positive electrode active material layer comprises the following components in percentage by mass:
80-99.8wt% of positive electrode active material, 0.1-10wt% of binder and 0.1-10wt% of conductive agent.
Preferably, the positive electrode active material layer comprises the following components in percentage by mass:
84-99wt% of negative electrode active material, 0.5-8wt% of binder and 0.5-8wt% of conductive agent.
Still preferably, the positive electrode active material layer comprises the following components in percentage by mass:
90-99wt% of positive electrode active material, 0.5-5wt% of binder and 0.5-5wt% of conductive agent.
According to the invention, the lithium iron phosphate has a median particle diameter of 0.2 to 5. Mu.m, such as 0.4 to 2. Mu.m, such as 0.5 to 1.5. Mu.m.
According to the invention, the specific surface area of the lithium iron phosphate is 4-22m 2 /g, e.g. 5-20m 2 /g, e.g. 6-15m 2 /g。
The lithium iron phosphate is used as the positive electrode active material, the energy density of the lithium ion battery can be improved, meanwhile, the specific surface area and the median particle size of the lithium iron phosphate are further limited, and the migration distance of lithium ions in the positive electrode active material can be reduced by adopting the lithium iron phosphate with the median particle size and the specific surface area, so that the lithium ions in the lithium iron phosphate can be rapidly released and intercalated, and the lithium ion battery has better power density. The main bottlenecks of high-power discharge lithium ion batteries are the transmission of lithium ions and the intercalation of lithium ions into the positive electrode. The lithium iron phosphate with the specified surface area and median particle diameter has better power performance, but the high-temperature performance is poorer, and the high-temperature performance can be obviously improved by combining the electrolyte provided by the invention, because the additives can form a protective layer with more inorganic components on the surface of the positive electrode, the formation mechanism is that the lithium ions have strong solvation capability in the ethyl 3-methoxypropionate, and the lithium ions can be formed moreMultiple ethyl 3-methoxypropionate solvated clusters. The electrolyte of the invention can form Li when charged for the first time + [ (3-methoxy-propionic acid ethyl ester) a (difluorophosphate) b (vinyl sulfate) c (vinylene carbonate) d (borophosphate oxalate) e ] - The solvated clusters of (a) have lower oxidation potential than those of vinyl sulfate, lithium difluorophosphate, vinylene carbonate, boron-phosphorus lithium oxalate and the like when used alone, and can form a protective film on the surface of the positive electrode material better. In the absence of ethyl 3-methoxypropionate, organic sulfur-containing compounds, boron-containing compounds, and the like having poor thermal stability, such as vinyl sulfate, vinylene carbonate, and boron-phosphorus lithium oxalate, are formed, and the inorganic layer formed by oxidation of the clusters has a main component of Li 2 CO 3 、Li 2 SO 4 、LiBO 3 、Li 3 PO 4 And LiF, these inorganic components have a high decomposition temperature and are not easily dissolved by the electrolyte. Therefore, the inorganic protective layers have higher strength, can be stable and not broken under high temperature conditions, can better protect the anode and prevent the electrolyte from being oxidized by the anode, and therefore have better high temperature and safety performance.
According to the present invention, the anode includes an anode active material layer and an anode current collector, the anode active material layer is provided on one side or both side surfaces of the anode current collector, and the anode active material layer includes an anode active material, a conductive agent, a dispersant, and a binder.
According to the present invention, the negative electrode active material is at least one of graphite, a silicon-containing compound, and silicon.
According to the invention, the material of the negative electrode current collector can be at least one of copper foil, foam nickel and foam copper.
According to the present invention, the conductive agent may be at least one selected from natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, graphene, and carbon nanotubes.
According to the present invention, the binder may be at least one selected from sodium carboxymethyl cellulose (CMC), styrene Butadiene Rubber (SBR), polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethylene oxide-containing polymer, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyvinyl alcohol, sodium polyacrylate.
According to the invention, the negative electrode active material layer comprises the following components in percentage by mass:
70-99.7wt% of negative electrode active material, 0.1-10wt% of binder, 0.1-10wt% of dispersing agent and 0.1-10wt% of conductive agent.
Preferably, the mass percentage of each component in the anode active material layer is as follows:
76-98.5wt% of negative electrode active material, 0.5-8wt% of binder, 0.5-8wt% of dispersing agent and 0.5-8wt% of conductive agent.
Still preferably, the mass percentage of each component in the negative electrode active material layer is:
85-98.5wt% of negative electrode active material, 0.5-5wt% of binder, 0.5-5wt% of dispersing agent and 0.5-5wt% of conductive agent.
According to the present invention, the binder is at least one polymer selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethyleneimine (PEI), polyaniline (PAN), polyacrylic acid (PAA), sodium alginate, styrene-butadiene rubber (SBR), sodium carboxymethyl cellulose (CMC-Na), phenolic resin and epoxy resin.
According to the present invention, the dispersant is at least one selected from Polypropylene (PVA), cetyl ammonium bromide, sodium dodecylbenzenesulfonate, a silane coupling agent, ethanol, N-methylpyrrolidone (NMP), N-Dimethylformamide (DMF), etc., more preferably at least one selected from cetyl ammonium bromide, sodium dodecylbenzenesulfonate, a silane coupling agent, ethanol.
According to the present invention, the conductive agent is at least one selected from among industrially common conductive agents such as Carbon Nanotubes (CNTs), carbon fibers (VGCF), conductive graphite (KS-6, SFG-6), mesophase Carbon Microspheres (MCMB), graphene, ketjen black, super P, acetylene black, conductive carbon black, or hard carbon.
According to the present invention, the separator may be a separator material commonly used in lithium ion batteries at present, such as one of a coated or uncoated polypropylene separator (PP), a polyethylene separator (PE), and a polyvinylidene fluoride separator.
According to the invention, the lithium ion battery is a high-power lithium ion battery, and the power density is more than or equal to 5000W/kg, such as 5000-8000W/kg.
According to the invention, the capacity retention rate of the lithium ion battery is more than or equal to 85% after the lithium ion battery is stored for 90 days at 60 ℃.
According to the invention, the capacity recovery rate of the lithium ion battery after being stored at 60 ℃ for 90 days is more than or equal to 89%.
According to the invention, the thickness change rate of the lithium ion battery after being stored at 60 ℃ for 90 days is less than or equal to 6%.
According to the invention, the capacity retention rate of the lithium ion battery after 500 weeks of circulation at 55 ℃ is more than or equal to 86%.
According to the invention, the voltage of the lithium ion battery after the discharge of the 10C multiplying power for 2s is more than or equal to 2.4V.
The beneficial effects are that:
1. the invention adopts the lithium iron phosphate anode material with better power performance, and simultaneously uses the solvent with high lithium ion mobility, the additive combination and the lithium salt to improve the power performance of the electrolyte.
2. The electrolyte additive can be used for protecting the film with higher performance strength on the surface of the anode and the cathode so as to improve the high-temperature performance of the battery. Meanwhile, the lithium salt with higher decomposition temperature is used, so that the safety performance of the lithium ion battery is improved.
Detailed Description
The present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the invention. All techniques implemented based on the above description of the invention are intended to be included within the scope of the invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; the reagents, materials, etc. used in the examples described below are commercially available unless otherwise specified.
Examples and comparative examples
(1) Preparation of electrolyte:
the electrolytes of each example and comparative example (specific differences are shown in table 1) were obtained by thoroughly mixing the solvents, conductive lithium salts, and additives in different components and amounts under an inert atmosphere (moisture <10ppm, oxygen <1 ppm).
(2) Preparation of a positive plate:
dispersing lithium iron phosphate (different specific surface areas and median particle diameters are shown in table 1), a conductive agent acetylene black and a binder polyvinylidene fluoride (PVDF) in a proper amount of N-methyl pyrrolidone (NMP) solvent according to a mass ratio of 90:5:5, and fully stirring and mixing to form uniform anode slurry; and uniformly coating the anode slurry on the anode current collector Al, and drying, rolling and cutting to obtain the anode plate.
(3) Preparing a negative plate:
dispersing negative electrode active material graphite, conductive agent acetylene black, binder sodium carboxymethylcellulose (CMC) and Styrene Butadiene Rubber (SBR) in a proper amount of deionized water according to a mass ratio of 95:2:2:1, and fully stirring and mixing to form uniform negative electrode slurry; and uniformly coating the negative electrode slurry on the negative electrode current collector Cu, and drying, rolling and slitting to obtain the negative electrode plate.
(4) Assembling a battery:
and stacking the positive plate, the diaphragm and the negative plate in sequence, enabling the diaphragm to be positioned between the positive plate and the negative plate to play a role of isolation, then stacking to obtain a bare cell, placing the bare cell in an outer packaging shell, drying, and then injecting electrolyte. And the preparation of the lithium ion battery is completed through the procedures of vacuum packaging, standing, formation, shaping and the like.
TABLE 1
The batteries obtained in the above examples and comparative examples were tested as follows:
(a) High temperature storage experiment: the batteries obtained in examples and comparative examples were subjected to a charge-discharge cycle test 5 times at room temperature at a charge-discharge rate of 1C, and then the 1C rate was charged to a full-charge state. The 1C capacity Q and the battery thickness T are recorded separately. Storing the battery in full state at 60deg.C for 90 days, and recording battery thickness T 0 And 1C discharge capacity Q 1 The battery was then charged and discharged at 1C for 5 weeks at room temperature, and the 1C discharge capacity Q was recorded 2 Experimental data such as a high-temperature storage capacity retention rate, a capacity recovery rate, a thickness change rate and the like of the battery are calculated and recorded as a result in table 2. The calculation formula used therein is as follows: capacity retention (%) =q 1 Q.times.100%; capacity recovery rate (%) =q 2 Q.times.100%; thickness change rate (%) = (T) 0 -T)/T×100％。
(b) High temperature cycle test: the battery was left at 55℃and the initial capacity was recorded as A 1 The capacity of the selective circulation to 500 weeks is A 2 The capacity retention rate of the battery at a high temperature cycle of 500 weeks was calculated from the following formula: circulation capacity retention (%) =a 2 /A 1 X 100% and the results are reported in table 2.
(c) Multiplying power (power) performance test:
the battery having an SOC of 50% was left to stand at-30 ℃ for 3 hours, and then discharged for 2s using a 10C rate to obtain a voltage thereof, and the results are recorded as in table 2.
(d) Safety test: the batteries obtained in the fully charged examples and comparative examples were stored at 160℃for 1 hour, and the results are recorded in Table 2.
TABLE 2
From the above table, the lithium ion battery of the present invention has outstanding advantages, mainly in improving the high temperature storage performance, high temperature cycle and high rate discharge performance of the battery. The examples are clearly superior to their comparative examples. Therefore, the lithium ion battery has extremely high safety performance and durability, and extremely high market value and social benefit. The foregoing is a specific description of a possible embodiment of the invention, but is not intended to limit the scope of the invention.
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, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. An electrolyte comprising a conductive lithium salt, an additive, and a solvent; wherein the additive comprises at least four of lithium difluorophosphate, vinyl sulfate, vinylene carbonate and boron-phosphorus lithium oxalate; the solvent comprises ethyl 3-methoxypropionate;
the addition amount of the 3-methoxy ethyl propionate accounts for 10% -50% of the total mass of the electrolyte;
the boron-phosphorus lithium oxalate is at least one selected from compounds shown in the following structural formula:
；
wherein R is 1 -R 8 Identical or different, independently of one another, from H, F, halogen-substituted C 1-6 An alkyl group;
the conductive lithium salt is selected from lithium bis-fluorosulfonyl imide and lithium hexafluorophosphate;
the addition amount of the conductive lithium salt accounts for 14-20% of the total mass of the electrolyte.
2. The electrolyte of claim 1, wherein the solvent further comprises at least one of a cyclic carbonate, a linear carbonate, and a linear carboxylate.
3. The electrolyte according to claim 2, wherein the cyclic carbonate is selected from at least one of ethylene carbonate and propylene carbonate;
the linear carbonic ester is at least one of dimethyl carbonate, diethyl carbonate and ethylmethyl carbonate;
the linear carboxylic acid ester is selected from at least one of ethyl propionate, propyl propionate and propyl acetate.
4. The electrolyte according to any one of claims 1 to 3, wherein the addition amount of the boron-phosphorus lithium oxalate is 0.1 to 4% of the total mass of the electrolyte; and/or, the addition of the vinyl sulfate accounts for 0.1-5% of the total mass of the electrolyte; and/or, the addition of the lithium difluorophosphate accounts for 0.1-2% of the total mass of the electrolyte; and/or the addition of the vinylene carbonate accounts for 0.1% -3% of the total mass of the electrolyte.
5. A lithium ion battery comprising the electrolyte of any one of claims 1-4.
6. The lithium ion battery of claim 5, wherein the lithium ion battery further comprises a positive electrode, a negative electrode, a separator;
the positive electrode comprises a positive electrode active material layer and a positive electrode current collector, wherein the positive electrode active material layer is arranged on one side or two side surfaces of the positive electrode current collector, and comprises a positive electrode active material, a conductive agent and a binder, wherein the positive electrode active material is lithium iron phosphate; the median particle diameter of the lithium iron phosphate is 0.2-5 mu m; the specific surface area of the lithium iron phosphate is 4-22m 2 /g。
7. The lithium ion battery of claim 5 or 6, wherein the lithium ion battery has at least one of the following properties:
(1) The lithium ion battery is a high-power lithium ion battery, and the power density of the lithium ion battery is more than or equal to 5000W/kg;
(2) The capacity retention rate of the lithium ion battery after being stored at 60 ℃ for 90 days is more than or equal to 85%;
(3) The capacity recovery rate of the lithium ion battery after being stored at 60 ℃ for 90 days is more than or equal to 89%;
(4) The thickness change rate of the lithium ion battery after being stored at 60 ℃ for 90 days is less than or equal to 6%;
(5) The capacity retention rate of the lithium ion battery after the lithium ion battery is cycled at 55 ℃ for 500 weeks is more than or equal to 86%;
(6) The voltage of the lithium ion battery after the discharge of the 10C multiplying power for 2s is more than or equal to 2.4V.
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| CN111640987A (en) * | 2020-06-11 | 2020-09-08 | 珠海冠宇电池股份有限公司 | High-power electrolyte and lithium ion battery containing same |
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2020
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107210489A (en) * | 2015-03-17 | 2017-09-26 | 株式会社艾迪科 | Nonaqueous electrolytic solution and nonaqueous electrolytic solution secondary battery |
| JP2017195174A (en) * | 2016-04-14 | 2017-10-26 | 株式会社Adeka | Method for manufacturing electrode for nonaqueous electrolyte secondary battery |
| CN108598574A (en) * | 2018-04-16 | 2018-09-28 | 东莞市杉杉电池材料有限公司 | A kind of lithium-ion battery electrolytes and the lithium ion battery containing the electrolyte |
| CN109713366A (en) * | 2018-12-13 | 2019-05-03 | 风帆有限责任公司 | A kind of electrolyte and dynamic lithium battery for high power start and stop battery |
| CN110212235A (en) * | 2019-06-12 | 2019-09-06 | 广州天赐高新材料股份有限公司 | A kind of lithium secondary cell electrolyte and its lithium secondary battery reducing battery impedance |
| CN110556580A (en) * | 2019-10-15 | 2019-12-10 | 骆驼集团武汉光谷研发中心有限公司 | Start-stop battery electrolyte and lithium ion battery |
| CN111640987A (en) * | 2020-06-11 | 2020-09-08 | 珠海冠宇电池股份有限公司 | High-power electrolyte and lithium ion battery containing same |
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