High-voltage electrolyte for lithium ion battery and lithium ion battery

Abstract

The invention discloses a high-voltage electrolyte for a lithium ion battery and the lithium ion battery. The electrolyte comprises the following raw materials of a lithium salt, a non-aqueous solvent, an additive A and an additive B, wherein the non-aqueous solvent is a mixed solvent of linear carbonate ester and cyclic carbonate ester, the additive A is a benzothiophene or dibenzothiophene solvent, and the additive B is propenyl-1, 3-sultone. In the high-voltage electrolyte for the lithium ion battery and the lithium ion battery, a solvent containing a sulfur element is used as a high-voltage additive of the lithium ion electrolyte, oxidization and decomposition of the carbonate solvent on a surface of an electrode can be reduced, the propenyl-1, 3-sultone has good negative electrode film formation performance, a negative electrode material can be effectively coated, and the room-temperature cycle property under a high voltage can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a high-voltage electrolyte for lithium-ion batteries and the lithium-ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, large specific capacity, long cycle life, no memory effect, and environmental friendliness. They are widely used in various electronic devices. With the wide application of lithium-ion batteries in electric vehicles, people Higher requirements are put forward for the energy density of the battery. The currently used ternary materials, lithium iron phosphate and other positive electrode materials can carry out the deintercalation reaction of lithium ions at a very high voltage, which provides a new way for people to improve the energy density of the battery. approach, but the current lithium-ion battery electrode solution of the conventional organic carbonate system is easily oxidized and de...

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Problems solved by technology

[0002] Lithium-ion batteries have the advantages of high working voltage, large specific capacity, long cycle life, no memory effect, and environmental friendliness. They are widely used in various electronic devices. With the wide application of lithium-ion batteries in electric vehicles, people Higher requirements are put forward for the energy density of the battery. The currently used ternary materials, lithium iron phosphate and other positive electrode materials can carry out the deintercalation reaction of lithium ions at a very high voltage, which provides a new way for people to improve the energy density of the battery. approach, but the current lithium-ion battery electrode solution of the conventional organic carbonate system is easily oxidized and decomposed at high temperature, producing a large amount of gas, increasing the internal pressure of the battery, and having a very negative impact on the cycle performance and safety performance of the battery. Further development of high-voltage lithium-ion batteries, so a high-voltage electrolyte for lithium-ion batteries and lithium-ion batteries are proposed

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