CN-121990978-A - Electrolyte additive for aluminum foil and application thereof

Abstract

The invention belongs to the technical field of electrolyte additives, and discloses an electrolyte additive for an aluminum foil and application thereof, wherein the electrolyte additive for the aluminum foil comprises an organic solvent, electrolyte lithium salt, a sulfur-containing additive and a compound, the organic solvent comprises cyclic carbonate and chain carbonate, the cyclic carbonate comprises at least one of ethylene carbonate and propylene carbonate, the chain carbonate comprises two or three of diethyl carbonate, dimethyl carbonate and methyl ethyl carbonate, the total mass of the cyclic carbonate and the chain carbonate is (35-45): (55-65), the problem that lithium bis-fluorosulfonyl imide corrodes the aluminum foil under high voltage in the prior art is solved, and the comprehensive performance of a supercapacitor is improved.

Inventors

• SUN GUOHUI
• WANG BAOLONG
• WU PENGYUE
• ZHANG LISONG
• CHEN SI
• Lou Fangxi
• XUE LEI
• Dai Benqian
• WANG XIAOHUI
• WANG HAIFENG
• SUN YIHUI
• DONG LILI
• HAN BOWEN
• MA XINYU
• ZHANG LIJING
• TANG ZHENYANG

Assignees

• 华能伊敏煤电有限责任公司
• 西安热工研究院有限公司

Dates

Publication Date

20260508

Application Date

20260120

Claims (10)

1. 1. A compound for aluminum foil, characterized by having the structure of formula I: General formula I.
2. 2. An electrolyte additive for aluminum foil, comprising: An organic solvent, an electrolyte lithium salt, a sulfur-containing additive, and a compound as claimed in claim 1.
3. 3. An electrolyte additive for aluminum foil according to claim 2, wherein the organic solvent comprises cyclic carbonate and chain carbonate.
4. 4. An electrolyte additive for aluminum foil according to claim 3, wherein the cyclic carbonate comprises at least one of ethylene carbonate and propylene carbonate; The chain carbonate comprises two or three of diethyl carbonate, dimethyl carbonate and ethylmethyl carbonate.
5. 5. An electrolyte additive for aluminum foil according to claim 3, wherein the total mass of the cyclic carbonate and the chain carbonate is (35-45): (55-65).
6. 6. An electrolyte additive for aluminum foil according to claim 2, wherein the sulfur-containing additive comprises at least one of vinyl sulfate, methylene methane disulfonate, 1, 3-propenesulfonic acid lactone; the electrolyte lithium salt is lithium hexafluorophosphate.
7. 7. The electrolyte additive for aluminum foil of claim 2, further comprising a lithium salt additive comprising at least one of lithium difluorophosphate, lithium bisoxalato borate.
8. 8. The electrolyte additive for aluminum foil according to claim 7, wherein the mass ratio of the compound to the sulfur-containing additive to the lithium salt additive is (0.8-1.5): 1.8-3): 3.5-4.8.
9. 9. The electrolyte additive for aluminum foil according to claim 8, wherein the electrolyte lithium salt is lithium hexafluorophosphate, and the mass percentage of the electrolyte lithium salt is 10% -15%.
10. 10. Use of an electrolyte additive for aluminium foil according to any one of claims 2 to 9 in a supercapacitor.

Description

Electrolyte additive for aluminum foil and application thereof Technical Field The invention relates to the technical field of electrolyte additives, in particular to an electrolyte additive for aluminum foil and application thereof. Background The super capacitor is a novel high-performance energy storage device and is arranged between a traditional capacitor and a battery. Its core advantage is high power density, quick charge and discharge in several seconds, long service life (hundreds of thousands times), and far beyond that of battery. The device stores energy through electrostatic adsorption (electric double layer principle) or rapid oxidation-reduction reaction (pseudo capacitance) on the surface of the electrode, and does not generate chemical reaction in the charge-discharge process, so that the device has high efficiency, small heat generation and good safety. The method is mainly applied to the scenes requiring instant high power, such as start-stop energy recovery of electric automobiles, braking energy storage of rail transit, power compensation of a smart grid, a backup power supply of consumer electronic equipment and the like, and short plates with insufficient battery power and low energy of a traditional capacitor are made up. In recent years, high voltage tolerant supercapacitor technology has received attention as a critical path for increasing the energy density of electrochemical energy storage devices. With the increasing demand of super-capacitors for high energy density, the continuous increase of the operating voltage becomes one of the key paths. Lithium bis (fluorosulfonyl imide) (LiFSI) is considered to be an ideal lithium salt for replacing conventional lithium hexafluorophosphate (LiPF 6) due to its excellent ionic conductivity, thermal stability, and film forming ability to the negative electrode interface. However, liFSI can severely corrode aluminum foil current collectors under high voltage (typically >4.2V vs. Li/Li +) conditions, which is a fatal defect that severely restricts its application in advanced supercapacitor systems such as high voltage ternary (e.g., NCM811, NCA) and the like. In the prior art, the mixed salt of LiSI and LiPF 6 can alleviate corrosion to a certain extent, but the high conductivity advantage of LiSI is sacrificed, and the addition of the conventional corrosion inhibitor has the problems of limited effect or negative influence on the overall electrochemical performance of the supercapacitor. Therefore, developing a novel additive which can effectively inhibit corrosion of LiFSI to aluminum foil, does not influence and even can improve the comprehensive performance of the super capacitor becomes a technical problem to be broken through in the field. Disclosure of Invention The invention aims to provide an electrolyte additive for aluminum foil and application thereof, which are used for solving the problems existing in the prior art, solving the problem that lithium bis (fluorosulfonyl) imide corrodes aluminum foil under high voltage in the prior art and improving the comprehensive performance of a supercapacitor. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: In a first aspect, the present invention provides a compound for aluminum foil having the structure of formula I (CAS: 145193-98-2): General formula I. In a second aspect, the present invention provides an electrolyte additive for aluminum foil comprising: organic solvents, electrolyte lithium salts, sulfur-containing additives, and compounds. In some embodiments, the organic solvent includes cyclic carbonates and chain carbonates. In some embodiments, the cyclic carbonate comprises at least one of ethylene carbonate and propylene carbonate; The chain carbonate comprises two or three of diethyl carbonate, dimethyl carbonate and ethylmethyl carbonate. In some embodiments, the total mass of the cyclic carbonate and the chain carbonate is (35-45): 55-65. In some embodiments, the sulfur-containing additive comprises at least one of vinyl sulfate (DTD), methylene Methane Disulfonate (MMDS), 1, 3-propenesulfonic acid lactone (PST); the electrolyte lithium salt is lithium hexafluorophosphate. In some embodiments, a lithium salt additive is also included, the lithium salt additive including at least one of lithium difluorophosphate (LiPO 2F2), lithium bisoxalato borate (LiBOB). In some embodiments, the mass ratio of the compound to the sulfur-containing additive to the lithium salt additive is (0.8-1.5): 1.8-3): 3.5-4.8. In some embodiments, the electrolyte lithium salt is lithium hexafluorophosphate (LiPF 6), and the mass percentage of the electrolyte lithium salt is 10% -15%. In a third aspect, the present invention provides the use of an electrolyte additive for aluminium foil in a supercapacitor. The technical scheme has the following advantages or beneficial effects: In a first aspect, the present invention provides a compound for aluminum