Electrolyte and lithium ion battery containing same

Abstract

The application relates to an electrolyte and a lithium ion battery containing the same. The electrolyte comprises an organic solvent, a lithium salt and an additive, wherein the additive comprises nitrogen-containing heterocyclic ring-boron trifluoride coordination compound and a silica phosphatide compound, and the nitrogen-containing heterocyclic ring is selected from at least one of heterocyclic ring containing pyridyl, heterocyclic ring containing pyridazine, heterocyclic ring containing pyrimidyl, heterocyclic ring containing pyrazinyl, heterocyclic ring containing pyrryl, heterocyclic ring containing pyrazolyl and heterocyclic ring containing imidazolyl. In the electrolyte provided by the application, the nitrogen-containing heterocyclic ring-boron trifluoride coordination compound and the silica phosphatide compound are simultaneously contained, and thus, the cycle performance of the lithium ion battery in a normal temperature and a high temperature can be improved.

Description

technical field [0001] The present application relates to the field of lithium batteries, in particular to an electrolyte and a lithium ion battery comprising the electrolyte. Background technique [0002] At present, the positive electrode active materials used in lithium-ion batteries mainly include lithium manganate, lithium cobaltate, ternary materials, lithium iron phosphate, etc. Under normal circumstances, the lithium-ion battery with the above-mentioned positive electrode materials The charging cut-off voltage of the lithium-ion battery does not exceed 4.2V, but with the advancement of technology and the continuous development of the market, it is increasingly important and urgent to increase the energy density of lithium-ion batteries. An effective way to increase the energy density of lithium-ion batteries is to develop high-voltage Lithium Ion Battery. [0003] However, for example, at a high voltage of 4.6V, it will cause the conventional electrolyte to oxidize ...

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Problems solved by technology

[0003] However, for example, at a high voltage of 4.6V, it will cause the conventional electrolyte to oxidize and decompose on the surface of the positive electrode of the battery. The oxidative decomposition of the electrolyte itself will also promote the deterioration of the positive active material, which will further affect the performance of the lithium-ion battery, such as cycle performance

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