CN117080558A - Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof - Google Patents

Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof Download PDF

Info

Publication number
CN117080558A
CN117080558A CN202311166265.4A CN202311166265A CN117080558A CN 117080558 A CN117080558 A CN 117080558A CN 202311166265 A CN202311166265 A CN 202311166265A CN 117080558 A CN117080558 A CN 117080558A
Authority
CN
China
Prior art keywords
electrolyte
carbonate
additive
boron
phosphorus
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.)
Pending
Application number
CN202311166265.4A
Other languages
Chinese (zh)
Inventor
孙春胜
郭营军
邹凯
朱少华
申海鹏
汪宇凡
王艳杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xianghe Kunlun New Energy Materials Co ltd
Original Assignee
Xianghe Kunlun New Energy Materials Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xianghe Kunlun New Energy Materials Co ltd filed Critical Xianghe Kunlun New Energy Materials Co ltd
Priority to CN202311166265.4A priority Critical patent/CN117080558A/en
Publication of CN117080558A publication Critical patent/CN117080558A/en
Pending legal-status Critical Current

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
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • 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
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using 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

The invention provides a phosphorus-boron-containing electrolyte additive, an electrolyte and application thereof, wherein the phosphorus-boron-containing electrolyte additive comprises ionic liquid with a compound structure shown in a formula I, and the electrolyte comprises electrolyte, an organic solvent and an additive, and the additive comprises ionic liquid with a compound structure shown in the formula I. The electrolyte prepared by adding the electrolyte additive containing the phosphorus and boron elements can improve the electrochemical performance of an electrochemical device, including the rate discharge performance, the charge and discharge cycle performance and the low-temperature discharge performance.

Description

Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof
Technical Field
The invention belongs to the technical field of electrolyte materials, and particularly relates to a phosphorus-boron-containing electrolyte additive, an electrolyte and application thereof.
Background
At present, the organic electrolyte materials used in the lithium battery industry are mainly alkyl carbonate compounds and LiPF 6 Lithium salt systems have greatly reduced performance at high temperatures, whereas power cells for example for electric vehicles require a higher operating temperature range (about-30 to 80 ℃); moreover, the alkyl carbonate organic electrolyte material has high flammability, so that great potential safety hazard exists; particularly in the fields of hybrid and all-electric automobile application, long-term circulation problems and safety are important factors limiting the practical application of the materials.
The electrolyte is an important component of a lithium ion battery and plays a role in transmitting lithium ions between the anode and the cathode. The safety of the battery, the charge-discharge cycle, the operating temperature range, the charge-discharge capacity of the battery, and the like are all important relationships with the electrochemical performance of the electrolyte. The traditional functional components in the electrolyte play a key role in prolonging the service life of the battery, but no long-term effective measures exist at present for delaying or inhibiting the generation of lithium dendrites, so that the safety performance of the battery and the service life of charge-discharge cycles are greatly influenced.
CN110600802a discloses a high-safety lithium ion battery electrolyte and a lithium ion battery, wherein the high-safety lithium ion battery electrolyte comprises an organic solvent, lithium salt and an additive, the additive comprises a main additive and an auxiliary additive, and the main additive is at least one of pyrrole ionic liquid and phosphorus-containing ionic liquid. According to the technical scheme, the lithium ion battery electrolyte prepared by adding the additive can improve the cycle life of the battery, the electrode stability and the flame retardant effect of the battery.
CN109830747a discloses an electrolyte additive, an electrolyte and application of the electrolyte, wherein the additive is a phosphorus-containing and boron-containing organic compound salt, the cation part of the additive is a phosphorus-containing cation with four benzene rings, and the anion part of the additive is a boron-containing anion with four benzene rings, and the structural general formula is as follows:
the additive provided by the technical scheme is used in the electrolyte, has a remarkable effect of inhibiting dendrites, and can improve the cycle performance and the safety performance of a metal lithium (or sodium or potassium) battery.
CN115441052a discloses a preparation method and application of electrolyte additive composition, the additive composition is a mixture of single-substituted difluorophosphate lithium trifluoroborate and lithium tetrafluoroborate shown in the following formula (I),
the additive composition provided by the technical scheme is used in electrolyte, and has the advantages of reducing the impedance of a battery, improving the high-temperature circulation, normal-temperature circulation and high-temperature storage performance of the battery, improving the long-term storage stability of the battery and the like.
Although various electrolyte additives have been developed to improve the safety performance and charge-discharge cycle performance of lithium ion batteries, and these electrolyte additives can inhibit the generation of lithium dendrites to some extent, the inhibition capability of these electrolyte additives on lithium dendrites is not enough to enable lithium metal cathodes to be applied to commercial batteries in large scale, and the requirements of batteries on high energy density and high-temperature high-voltage stability are increasingly high, and the inhibition capability of electrolyte additives on lithium dendrites still needs to be further improved.
Therefore, it is important to develop an additive that improves battery stability and charge-discharge cycle performance and an electrolyte.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide an electrolyte additive containing phosphorus and boron elements, an electrolyte and application thereof. The electrolyte prepared by adding the electrolyte additive containing the phosphorus and boron elements can improve the electrochemical performance of an electrochemical device, including the charge-discharge cycle performance and the low-temperature discharge performance.
To achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the invention provides a phosphorus-boron-containing electrolyte additive, which comprises ionic liquid with a compound structure shown in a formula I,
wherein R is 1 、R 2 And R is 3 Each independently selected from a halogen atom or an organic group having 1 to 10 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.), the dotted line represents a conjugated pi bond.
In the invention, the ionic liquid with the structure shown in the formula I is used as an electrolyte additive, so that the prepared electrochemical device has the characteristics of excellent comprehensive performance, high charge-discharge cycle stability and good low-temperature discharge performance.
In the invention, the ionic liquid with the structure shown in the formula I has the action mechanism in electrolyte: the difluoro phosphorus oxygen group in the anion structure of the ionic liquid with the compound structure shown in the formula I can improve the stability of the electrolyte; the acting force of the anion structure with larger space structure and the electrolyte solvent is weaker, so that the oxidation resistance of the electrolyte can be improved; the lone pair electrons on the nitrogen atoms in the cation structure can capture transition metal ions diffused from the positive electrode and dissociated in the electrolyte, so that the damage of the transition metal ions to the negative electrode interface is prevented, and the SEI interface film is stabilized, and the cycle life, the rate capability and the low-temperature capability of the electrochemical device are improved.
In the present invention, "low temperature" means-30 to-20℃and "high temperature" means 45 to 80℃and the same meaning as the same expression is given below.
Preferably, the halogen atom is any one of fluorine, chlorine, bromine or iodine.
Preferably, the organic group having 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.) is an alkyl group having 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.), an alkoxy group having 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.), an alkenyl group having 2 to 10 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.), an alkynyl group having 2 to 10 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10, etc.), an aryl group having 5 to 10 (e.g., 5, 6, 7, 8, 9, or 10, etc.), or a cycloalkyl group having 5 to 10 (e.g., 5, 6, 7, 8, 9, or 10, etc.).
Preferably, the cycloalkyl group having 5 to 10 carbon atoms (e.g., 5, 6, 7, 8, 9, or 10, etc.) includes a five-membered cycloalkyl group or a six-membered cycloalkyl group.
Preferably, said R 1 、R 2 And R is 3 Each independently selected from methyl or propyl.
Preferably, the electrolyte additive containing the phosphorus and boron elements comprises a compound shown as a formula II and/or a formula III,
in a second aspect, the present invention provides an electrolyte comprising an electrolyte, an organic solvent and an additive comprising the electrolyte additive of the phosphorus-boron-containing element of the first aspect.
Preferably, the electrolyte comprises any one or a combination of at least two of lithium salt, sodium salt or potassium salt.
Preferably, the electrolyte comprises XClO 4 、XPF 6 、XBF 4 、XTFSI、XFSI、XBOB、XODFB，XCF 3 SO 3 XDFP, XDODFP, XOTFP or XASF 6 Any one or a combination of at least two, wherein X comprises any one of Li, na or K.
Preferably, the mass percentage of the electrolyte is 8% -49%, for example 8%, 10%, 12%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 49%, etc., more preferably 8-18%, based on 100% of the total mass of the electrolyte.
Preferably, the organic solvent comprises a non-aqueous organic solvent.
Preferably, the organic solvent includes any one or a combination of at least two of carbonate, carboxylate, fluorocarboxylate, propionate, fluoroether compound, or aromatic hydrocarbon.
Preferably, the carbonate comprises a halogenated carbonate and/or a non-halogenated carbonate.
Preferably, the method comprises the steps of, the halogenated carbonates comprise fluoroethylene carbonate, propylene carbonate, ethyl trifluoroacetate, ethyl trifluoromethyl carbonate, vinyl trifluoromethyl carbonate, 4-trifluoromethyl ethylene carbonate, vinyl chlorocarbonate bis (2, 2-trifluoroethyl) carbonate, methyl trifluoropropionate, ethyl 3, 3-trifluoroacetate, methyl 2-trifluoromethylbenzoate ethyl 4, 4-trifluorobutyrate or 1, 3-hexafluoroisopropyl acrylate, or a combination of at least two.
Preferably, the non-halogenated carbonate comprises any one or a combination of at least two of ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate or ethylmethyl carbonate.
Preferably, the carboxylic acid esters include halogenated carboxylic acid esters and/or non-halogenated carboxylic acid esters.
Preferably, the halogenated carboxylic acid ester comprises any one or a combination of at least two of propyl fluorobutyrate, propyl fluoroacetate, isopropyl fluoroacetate, butyl fluoropropionate, isopropyl fluoropropionate, ethyl fluorobutyrate, methyl fluoropropionate, ethyl fluoropropionate or propyl fluoropropionate.
Preferably, the non-halogenated carboxylic acid ester comprises any one or a combination of at least two of propyl butyrate, propyl acetate, isopropyl acetate, butyl propionate, isopropyl propionate, ethyl butyrate, methyl propionate, ethyl propionate, or propyl propionate.
Preferably, the fluoroether compound has a carbon number of 7 or less, for example, 1, 2, 3, 4, 5, 6 or 7, etc.
Preferably, the aromatic hydrocarbon comprises halogenated aromatic hydrocarbon and/or non-halogenated aromatic hydrocarbon.
Preferably, the halogenated aromatic hydrocarbon comprises any one or a combination of at least two of monofluorobenzene, difluorobenzene, 1,3, 5-trifluorobenzene, benzotrifluoride, 2-fluorotoluene or 2, 4-dichlorobenzotrifluoride.
Preferably, the mass percentage of the organic solvent is 1% -85%, for example 1%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80% or 85%, etc., based on 100% of the total mass of the electrolyte.
Preferably, the additive is present in a mass percentage of 0.01% -3%, such as 0.01%, 0.05%, 0.1%, 0.3%, 0.5%, 1%, 1.5%, 1.8%, 2%, 2.5% or 3% based on 100% of the total mass of the electrolyte.
Preferably, the electrolyte further comprises other additives.
In a third aspect, the present invention provides an electrochemical device comprising an electrolyte additive according to the first aspect and/or an electrolyte according to the second aspect.
Preferably, the electrochemical device includes any one of a lithium ion battery, a sodium ion battery, a potassium ion battery, or a supercapacitor.
Preferably, the negative electrode material of the lithium ion battery comprises any one or a combination of at least two of graphite, soft carbon, hard carbon, a composite material of monocrystalline silicon and graphite, a composite material of silicon oxide and graphite, lithium titanate or niobium pentoxide.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the ionic liquid with the structure shown in the formula I is selected as the electrolyte additive, so that the problems of low safety performance and poor charge-discharge cycling stability of the current electrochemical device are solved. The lithium battery prepared by adding the electrolyte additive containing the phosphorus and boron has the characteristics of excellent electrochemical performance, high charge and discharge cycle stability and good low-temperature discharge performance. The lithium ion battery prepared by adding the electrolyte containing the electrolyte additive of the phosphorus and boron elements has a 3C charging rate of 76.6-85.1 percent at normal temperature, a 1C discharging rate of 78.2-87.9 percent at-20 ℃, a cycle capacity retention rate of 90.0-97.0 percent after normal temperature cycle 800 times of 3C charging/1C discharging, and a cycle capacity retention rate of 87.5-94.4 percent after 45 ℃ high temperature cycle 800 times of 3C charging/1C discharging.
Detailed Description
The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
The electrolyte additive containing the phosphorus and boron elements used in example 1-example 21 was derived from santa chemical of Shimadzu (purity 99.5%).
Example 1
The embodiment provides an electrolyte additive containing phosphorus and boron and an electrolyte, wherein the electrolyte additive containing phosphorus and boron is a compound shown in a formula II.
An electrolyte, the preparation method of which is as follows: preparing an electrolyte in a glove box, uniformly mixing Ethylene Carbonate (EC), methyl ethylene carbonate (EMC) and diethyl carbonate (DEC) according to a mass ratio of 3:5:2 to obtain an organic solvent, and mixing 82.9wt% of the organic solvent and 15wt% of LiPF which is fully dried 6 Mixing, adding 0.1wt% of a compound shown in a formula II, and adding 1wt% of Vinylene Carbonate (VC) and 1wt% of 1, 3-Propane Sultone (PS) to prepare an electrolyte, wherein the total weight of the electrolyte is 100wt%.
Examples 2 to 21
Examples 2-21 respectively provide an electrolyte additive and an electrolyte containing phosphorus and boron, wherein the electrolyte comprises 1% of VC and 1% of PS by mass percent, and the preparation method is the same as that of example 1.
TABLE 1
Wherein "-" represents that the component was not added, PC represents propylene carbonate, PP represents propyl propionate, and EP represents ethyl propionate.
Example 21
This example provides an electrolyte additive and electrolyte containing phosphorus and boron, which differ from example 4 only in that the electrolyte additive containing phosphorus and boron is a compound of formula IV,
other raw materials, amounts and preparation methods were the same as in example 4.
Comparative examples 1 to 2
Comparative examples 1-2 each provided an electrolyte having components in mass percent, each of which contained 1wt% of VC and 1wt% of PS, as shown in Table 2, and were prepared in the same manner as in example 1.
TABLE 2
Wherein "-" represents that the component was not added, PC represents propylene carbonate, PP represents propyl propionate, and EP represents ethyl propionate.
The electrolytes provided in experimental examples 1 to 19, example 21 and comparative example 1 were prepared into lithium ion batteries and subjected to performance test, and the preparation method was as follows:
1.0wt% of binder PVDF-S5130, 1.5wt% of composite conductive agent Super-P/KS-6 (the mass ratio Super-P: KS-6=2:1), 98.5wt% of NCM622 nickel cobalt manganese ternary positive electrode material and a proper amount of dispersant NMP (N-methyl pyrrolidone) are prepared into slurry with the solid content of 63%, and the slurry is baked by a mixer and a coater to prepare the positive electrode plate.
97.5wt% of graphite anode material (fir P15), 1.5wt% of conductive agent Super-P, 0.5wt% of CMC (sodium carboxymethyl cellulose) and 0.5wt% of binder SBR (purchased from Ruixian, brand 451B) are mixed with a proper amount of water, and a coating mechanism is used for preparing the anode plate.
The electrolytes provided in experimental examples 1 to 19, example 21 and comparative example 1 were assembled with the above positive electrode sheet and the above negative electrode sheet, respectively, to prepare a lithium ion battery, and the ratio (N/P ratio) of the negative electrode capacity to the positive electrode capacity of the battery was designed to be 1.12, and the capacity was 1671mAh.
Performance test:
(1) Charging rate performance: the 1C current is 1.67A, the 3C current is 5.01A, the charge-discharge potential range is 2.75V-4.30V, and the charging rate of the normal temperature 3C is the ratio of the capacity C2 of 3C constant current charging to the capacity C1 of 1C constant current charging.
(2) Cycle performance: the charge-discharge potential range is 2.75V-4.30V, the charge current is 3C (5.01A) to 4.30V, the constant voltage charge of 4.30V is less than or equal to 0.02C (0.0334A) of cut-off current, after standing for 5 minutes, 1C (1.67A) is discharged to 2.75V, and standing for 5 minutes; the charge and discharge were cycled in this manner, and the normal temperature cycle performance and the high temperature (45 ℃) cycle performance were respectively tested.
(3) Low temperature discharge performance: the discharge capacity of 1C (1.67A) at normal temperature 25 ℃ is marked as C1, after 4.30V is fully charged, the freezing is carried out for 4 hours at-20 ℃, the discharge is carried out to 2.75V by 1C (1.67A), the discharge capacity is marked as C2, and the discharge rate at-20 ℃ is marked as C2/C1.
The electrolytes provided in experimental example 20 and comparative example 2 were prepared into lithium ion batteries and performance test was performed, and the preparation method was as follows:
1.0wt% of binder PVDF-S5130, 1.5wt% of composite conductive agent Super-P/KS-6 (the mass ratio Super-P: KS-6=2:1), 98.5wt% of lithium cobaltate positive electrode material and a proper amount of dispersant NMP (N-methylpyrrolidone) are prepared into slurry with the solid content of 63%, and the slurry is baked by a mixer and a coater to prepare the positive electrode plate.
97.5wt% of silicon carbon negative electrode material (Bei Terui S420), 1.5wt% of conductive agent Super-P, 0.5wt% of CMC (sodium carboxymethyl cellulose) and 0.5wt% of binder SBR (purchased from Rui Wen, brand 451B) are mixed with a proper amount of water, and a negative electrode plate is manufactured through a coating mechanism.
The electrolytes provided in experimental example 20 and comparative example 2 were assembled with the positive electrode sheet and the negative electrode sheet, respectively, to prepare a lithium ion battery, and the N/P ratio was designed to be 1.12, and the capacity was 1671mAh.
Performance test:
(1) Charging rate performance: the 1C current is 1.85A, the 3C current is 5.55A, the charge-discharge potential range is 2.75V-4.30V, and the charging rate at normal temperature 3C is the ratio of the capacity C2 of 3C constant current charging to the capacity C1 of 1C constant current charging.
(2) Cycle performance: the charge-discharge potential range is 2.75V-4.30V, the charge current is 3C (5.55A) to 4.30V, the constant voltage charge of 4.30V is less than or equal to 0.02C (0.037A), after standing for 5 minutes, 1C (1.85A) is discharged to 2.75V, and standing for 5 minutes; the charge and discharge were cycled in this manner, and the normal temperature cycle performance and the high temperature (45 ℃) cycle performance were respectively tested.
(3) Low temperature discharge performance: the discharge capacity of 1C (1.85A) at normal temperature 25 ℃ is marked as C1, after 4.30V is fully charged, the freezing is carried out for 4 hours at-20 ℃, the discharge is carried out to 2.75V by 1C (1.85A), the discharge capacity is marked as C2, and the discharge rate at-20 ℃ is marked as C2/C1.
The test results are shown in tables 3 and 4.
TABLE 3 Table 3
TABLE 4 Table 4
From the data in tables 3 and 4, it is understood that the lithium ion battery prepared from the electrolyte provided in examples 1 to 21 has a 3C charging rate of 76.6 to 85.1%, a 1C discharging rate of 78.2 to 87.9% at-20 ℃, a cycle capacity retention rate of 90.0 to 97.0% for 800 times of 3C charging/1C discharging at normal temperature cycles, and a cycle capacity retention rate of 87.5 to 94.4% for 800 times of 3C charging/1C discharging at 45 ℃.
From the test results of examples 1 to 6 and examples 7 to 12, it is understood that as the mass percentage of the electrolyte additive containing the phosphorus and boron element increases, the 3C charge rate at normal temperature, the 1C discharge rate at-20 ℃, the normal temperature cycle performance and the high temperature cycle performance all increase and decrease.
As is clear from comparison of examples 15 and examples 1 to 6, if the mass percentage of the electrolyte additive containing the phosphorus and boron elements is too small, the 3C charging rate at normal temperature, the 1C discharging rate at-20 ℃, the normal temperature cycle performance and the high temperature cycle performance are all reduced; as is clear from comparison of examples 16 and examples 1 to 6, if the mass percentage of the electrolyte additive containing the phosphorus and boron element is too large, small insoluble particles exist in the electrolyte due to the problem of solubility, and the performance of the battery is further caused to show a deterioration trend; the electrolyte additive containing phosphorus and boron elements in specific mass percentages is proved to be added, and the prepared lithium ion battery has better performance.
As can be seen from comparison of examples 4 and examples 17 to 19, as the mass percentage of the electrolyte increases, the 3C charging rate at normal temperature increases and then decreases, and the 1C discharging rate at-20 ℃ decreases, and if the mass percentage of the electrolyte is higher (example 19), the 3C charging rate and the 1C discharging rate at-20 ℃ are lower, which proves that the performance of the prepared lithium ion battery is better when the electrolyte with the mass percentage of 8-18% is added.
In comparison with example 1 and example 7, if the electrolyte additive containing phosphorus and boron is not added (comparative example 1), the 3C charge rate at normal temperature, -1C discharge rate at 20 ℃, the normal temperature cycle performance, and the high temperature cycle performance are all reduced; as can be seen from comparison with example 21, if the electrolyte additive containing phosphorus and boron is not added (comparative example 2), the 3C charging rate at normal temperature, the 1C discharging rate at-20 ℃ and the normal temperature cycle performance and the high temperature cycle performance are all reduced, and the electrolyte added with the electrolyte additive containing phosphorus and boron can improve the charging rate performance, the cycle performance and the low temperature discharging performance of the lithium ion battery.
The applicant states that the present invention is illustrated by the above examples as an electrolyte additive, electrolyte and its use for phosphorus-boron-containing elements, but the present invention is not limited to, i.e. it is not meant that the present invention must be practiced in dependence upon the above examples. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.

Claims (10)

1. The electrolyte additive containing the phosphorus and boron elements is characterized by comprising ionic liquid with a compound structure shown in a formula I,
wherein R is 1 、R 2 And R is 3 Each independently selected from a halogen atom or an organic group having 1 to 10 carbon atoms, and the dotted line represents a conjugated pi bond.
2. The phosphorus-boron-containing electrolyte additive according to claim 1, wherein the halogen atom is any one of fluorine, chlorine, bromine or iodine;
preferably, the organic group with 1-10 carbon atoms is alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, alkenyl with 2-10 carbon atoms, alkynyl with 2-10 carbon atoms, aryl with 5-10 carbon atoms or cycloalkyl with 5-10 carbon atoms;
preferably, the cycloalkyl group having 5 to 10 carbon atoms includes a five-membered cycloalkyl group or a six-membered cycloalkyl group.
3. A phosphorus-boron-containing element according to claim 1 or 2An electrolyte additive, characterized in that R 1 、R 2 And R is 3 Each independently selected from methyl or propyl.
4. The electrolyte additive containing phosphorus and boron according to any one of claims 1 to 3, wherein the electrolyte additive containing phosphorus and boron comprises a compound represented by formula II and/or formula III,
5. an electrolyte comprising an electrolyte, an organic solvent and an additive, wherein the additive comprises the electrolyte additive comprising the phosphorus-boron element of any one of claims 1-4.
6. The electrolyte of claim 5, wherein the electrolyte comprises any one or a combination of at least two of a lithium salt, a sodium salt, or a potassium salt;
preferably, the electrolyte comprises XClO 4 、XPF 6 、XBF 4 、XTFSI、XFSI、XBOB、XODFB、XCF 3 SO 3 XDFP, XDODFP, XOTFP or XASF 6 Any one or a combination of at least two of the following;
wherein X comprises any one of Li, na or K;
preferably, the mass percentage of the electrolyte is 8% to 49%, more preferably 8% to 18%, based on 100% of the total mass of the electrolyte.
7. The electrolyte according to claim 5 or 6, wherein the organic solvent comprises a non-aqueous organic solvent;
preferably, the organic solvent comprises any one or a combination of at least two of carbonate, carboxylate, fluorocarboxylate, propionate, fluoroether compound or aromatic hydrocarbon;
preferably, the carbonate comprises a halogenated carbonate and/or a non-halogenated carbonate;
preferably, the method comprises the steps of, the halogenated carbonates comprise fluoroethylene carbonate, propylene carbonate, ethyl trifluoroacetate, ethyl trifluoromethyl carbonate, vinyl trifluoromethyl carbonate, 4-trifluoromethyl ethylene carbonate, vinyl chlorocarbonate bis (2, 2-trifluoroethyl) carbonate, methyl trifluoropropionate, ethyl 3, 3-trifluoroacetate, methyl 2-trifluoromethylbenzoate ethyl 4, 4-trifluorobutyrate or 1, 3-hexafluoroisopropyl acrylate, or a combination of at least two thereof;
preferably, the non-halogenated carbonate comprises any one or a combination of at least two of ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate or ethylmethyl carbonate;
preferably, the carboxylic acid esters include halogenated carboxylic acid esters and/or non-halogenated carboxylic acid esters;
preferably, the halogenated carboxylic acid ester comprises any one or a combination of at least two of propyl fluorobutyrate, propyl fluoroacetate, isopropyl fluoroacetate, butyl fluoropropionate, isopropyl fluoropropionate, ethyl fluorobutyrate, methyl fluoropropionate, ethyl fluoropropionate or propyl fluoropropionate;
preferably, the non-halogenated carboxylic acid ester comprises any one or a combination of at least two of propyl butyrate, propyl acetate, isopropyl acetate, butyl propionate, isopropyl propionate, ethyl butyrate, methyl propionate, ethyl propionate or propyl propionate;
preferably, the number of carbon atoms of the fluoroether compound is less than or equal to 7;
preferably, the aromatic hydrocarbon comprises halogenated aromatic hydrocarbon and/or non-halogenated aromatic hydrocarbon;
preferably, the halogenated aromatic hydrocarbon comprises any one or a combination of at least two of monofluorobenzene, difluorobenzene, 1,3, 5-trifluorobenzene, benzotrifluoride, 2-fluorotoluene or 2, 4-dichlorobenzotrifluoride;
preferably, the mass percentage of the organic solvent is 1% -85% based on 100% of the total mass of the electrolyte.
8. The electrolyte according to any one of claims 5 to 7, wherein the mass percentage of the additive is 0.01% to 3% based on 100% of the total mass of the electrolyte;
preferably, the electrolyte further comprises other additives.
9. An electrochemical device, characterized in that the electrochemical device comprises the electrolyte additive according to any one of claims 1-4 and/or the electrolyte according to any one of claims 5-8.
10. The electrochemical device of claim 9, wherein the electrochemical device comprises any one of a lithium ion battery, a sodium ion battery, a potassium ion battery, or a supercapacitor;
preferably, the negative electrode material of the lithium ion battery comprises any one or a combination of at least two of graphite, soft carbon, hard carbon, a composite material of monocrystalline silicon and graphite, a composite material of silicon oxide and graphite, lithium titanate or niobium pentoxide.
CN202311166265.4A 2023-09-11 2023-09-11 Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof Pending CN117080558A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311166265.4A CN117080558A (en) 2023-09-11 2023-09-11 Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311166265.4A CN117080558A (en) 2023-09-11 2023-09-11 Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof

Publications (1)

Publication Number Publication Date
CN117080558A true CN117080558A (en) 2023-11-17

Family

ID=88709835

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311166265.4A Pending CN117080558A (en) 2023-09-11 2023-09-11 Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof

Country Status (1)

Country Link
CN (1) CN117080558A (en)

Similar Documents

Publication Publication Date Title
CN113839093A (en) Non-aqueous electrolyte of lithium ion battery and application thereof
CN107359369B (en) Electrolyte and lithium ion battery
CN108987808B (en) High-voltage lithium ion battery non-aqueous electrolyte and lithium ion battery
CN110085906B (en) Nonaqueous electrolyte and lithium ion battery containing same
CN113161615B (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN114512721B (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN114597489A (en) Electrolyte containing fluorobenzene carbonate and battery composed of electrolyte
CN112186248B (en) Lithium ion battery non-aqueous electrolyte and lithium ion battery
CN112186254A (en) Electrolyte containing difluoro oxalic acid phosphorus imide lithium and lithium ion battery using electrolyte
CN114520371B (en) Nonaqueous electrolyte and lithium ion battery comprising same
CN113948775B (en) Electrolyte and battery comprising same
CN113991176B (en) Nonaqueous electrolyte and lithium battery using same
CN112186249B (en) Electrolyte containing fluoro-malonic acid difluoro-lithium phosphate and lithium ion battery containing electrolyte
CN111048836B (en) Electrolyte and lithium ion battery
CN114464889A (en) Non-aqueous electrolyte for high-voltage lithium ion battery and lithium ion battery thereof
CN117080558A (en) Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof
CN117117321A (en) Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof
CN117175010A (en) Electrolyte additive containing phosphorus and boron elements, electrolyte and application thereof
CN113130999A (en) Lithium ion battery electrolyte and lithium ion battery
CN113078357A (en) High-voltage lithium ion battery non-aqueous electrolyte and lithium ion battery
CN116759643A (en) Electrolyte and application thereof
CN113690490B (en) Phosphite lithium ion battery electrolyte additive and application thereof
CN115732756B (en) Electrolyte and secondary battery using same
CN112186250B (en) Electrolyte containing lithium bis (oxalato) phosphoryl imine and lithium ion battery using electrolyte
CN116995300A (en) Electrolyte and application thereof

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