Electrolyte additive, non-aqueous electrolyte and lithium ion battery

Abstract

The invention discloses an electrolyte additive, a non-aqueous electrolyte and a lithium ion battery. The electrolyte additive comprises a compound shown as a formula A, wherein R is sulfonyl fluoride or trifluoromethylsulfonyl. The electrolyte additive is high in solubility and good in wettability, and the low-temperature cycle performance of the lithium ion battery can be greatly improved under the condition that impedance is not increased.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to an electrolyte additive, a non-aqueous electrolyte and a lithium-ion battery. Background technique [0002] Lithium-ion batteries are widely used in 3C digital products, power tools, electric vehicles, aerospace and other fields due to their high operating voltage, high energy density, long life, wide operating temperature range, and environmental friendliness. As people's requirements for batteries are getting higher and higher, thin and light and high energy density have become the development trend of batteries, especially for 3C digital products, such as mobile phone batteries, tablet computers and photography equipment. The existing common commercial lithium-ion cathode materials include lithium iron phosphate, lithium cobaltate, and nickel-cobalt-manganese ternary materials. Low, so the energy density is not high enough. [0003] As the market de...

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Problems solved by technology

The existing common commercial lithium-ion cathode materials include lithium iron phosphate, lithium cobaltate, and nickel-cobalt-manganese ternary materials. Low, so the energy density is not high enough

[0003] As the market demand for high-energy-density lithium-ion batteries is increasing, increasing the charge cut-off voltage of positive electrode materials is an effective means to increase energy density, such as the commercial lithium cobalt oxide battery voltage 4.2V→4.35V→4.4V →4.45V→4.48V→4.5V, but there are also some problems in increasing the charging cut-off voltage of the positive electrode material (≥4.5V): For example, the compatibility of the conventional electrolyte used with the positive electrode material at high voltage is extremely poor, and commonly used Carbonate-based electrolytes are prone to oxidative decomposition under high voltage, and the by-products produced have a negative impact on the performance of lithium-ion batteries. Suffering from corrosion, especially at low temperatures, the low-temperature performance of lithium-ion batteries is obviously insufficient

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