A kind of battery electrolyte additive, electrolyte containing the additive and application thereof

An electrolyte additive and electrolyte technology, applied in the field of lithium-ion batteries, can solve the problems of poor performance at room temperature and high temperature, and achieve the effects of reducing reactivity, improving high-temperature storage and high-temperature cycle performance, and preventing the decomposition process.

CN109638353BActive Publication Date: 2021-01-01SHANSHAN ADVANCED MATERIALS QUZHOU CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2021-01-01

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Abstract

The invention belongs to the technical field of lithium ion batteries, and in particular relates to a battery electrolyte additive, an electrolyte containing the additive and applications thereof. The lithium-ion battery electrolyte additive provided by the present invention is composed of a fluorosulfonic acid compound with a structural formula I and a cyclic acid anhydride compound with a structural formula II; the electrolyte includes an electrolyte lithium salt, a non-aqueous organic solvent and an additive. The additives include negative electrode film-forming additives, fluorosulfonic acid compounds with structural formula I and acid anhydride compounds with structural formula II. The fluorosulfonic acid compound with structural formula I and the acid anhydride compound with structural formula II of the present invention can form a stable and dense interfacial protective film on the surface of the positive electrode material, inhibit the dissolution of metal ions in the positive electrode material under high temperature conditions, and effectively improve the lithium ion battery Excellent high and low temperature performance, rate performance, cycle performance and service life, which solves the problem that the temperature performance of the battery in the prior art cannot be taken into account.
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Description

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a battery electrolyte additive, an electrolyte containing the additive and applications thereof. Background technique

[0002] Due to the advantages of high operating voltage, high energy density, long cycle life and environmental friendliness, lithium-ion batteries are widely used in 3C digital, power tools, aerospace, energy storage, power vehicles and other fields. With the rapid development of electronic information technology and consumer products, higher requirements are put forward for the performance of lithium-ion batteries in all aspects, and the development of electrolytes with excellent comprehensive properties such as high rate, long cycle life, high capacity and high retention rate The system is one of the important goals of developing high-performance lithium-ion batteries, and it is also one of the important ways to improve the energy density of lith...

Examples

Embodiment 1

[0056] Preparation of electrolyte: In a glove box filled with argon, mix ethylene carbonate, diethyl carbonate and ethyl methyl carbonate according to the mass ratio of EC:DEC:EMC=1:1:1, and then add to the mixed solution Slowly add 12.5wt% lithium hexafluorophosphate based on the total weight of the electrolyte, 0.5wt% lithium bisfluorosulfonimide (LiTFSI) based on the total weight of the electrolyte and 2.5wt% lithium bisfluorosulfonimide based on the total weight of the electrolyte (LiFSI), finally add 1.0wt% of the compound with the structure shown in formula I based on the total weight of the electrolyte, 0.1wt% of the cyclic anhydride compound shown in the formula II, 2.0wt% vinyl sulfate (DTD) and 1.0 wt% fluoroethylene carbonate (FEC), and stir to obtain the lithium-ion battery electrolyte of Example 1.

[0057] Preparation of lithium-ion battery: stack the prepared positive electrode sheet, separator, and negative electrode sheet in order, so that the separator is in ...

Embodiment 2-12

[0058] Embodiment 2-12 and comparative example 1-9

[0059] In Examples 2-12 and Comparative Examples 1-9, except that the proportions of the components of the electrolyte are added as shown in Table 1, the others are the same as in Example 1. In addition, the structural formulas of the additives of formula I and additives of formula II in each embodiment are shown in Table 2.

[0060] Table 1 embodiment 1-12 and the composition ratio of each component of the electrolyte of comparative example 1-9

[0061]

[0062]

[0063]

[0064] Structural formula Ⅰ and structural formula Ⅱ specific material description in the embodiment of table 2

[0065]

[0066]

[0067] Performance Testing

[0068] Performance tests were performed on the batteries prepared in Examples 1-12 and Comparative Examples 1-9.

[0069] (1) Cycling performance test at room temperature: At 25°C, charge the divided battery to 4.35V at 1C constant current and constant voltage, with a cut-off cur...