Electrolyte additive, lithium ion battery electrolyte and lithium ion battery

Abstract

The invention discloses an electrolyte additive, a lithium ion battery electrolyte and a lithium ion battery, and the electrolyte additive comprises a compound shown as a structural formula 1, r1 to R4 are respectively and independently selected from hydrogen, halogen, substituted or unsubstituted C1-C12 alkyl groups, substituted or unsubstituted C2-C12 unsaturated groups, substituted or unsubstituted amino groups, substituted or unsubstituted acylamino groups and substituted or unsubstituted nitrogen-containing heterocyclic groups. The electrolyte additive disclosed by the invention is applied to the lithium ion battery, and the lithium ion battery has relatively good low-temperature discharge performance, high-temperature storage performance and cycle performance under high voltage.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an electrolyte additive, a lithium ion battery electrolyte and a lithium ion battery. Background technique [0002] Due to the advantages of high specific energy, long cycle life and no memory effect, lithium-ion batteries are widely used in mobile phones, computers, cameras, electric vehicles and other fields. However, with the continuous development of science and technology, various application fields have put forward higher requirements for the performance of lithium-ion batteries. Among them, the most urgent is to improve the energy density of lithium-ion batteries under the premise of ensuring safety. At present, the energy density of lithium-ion batteries is often improved by increasing the charge cut-off voltage, but there are also some problems at high voltages: when the voltage reaches 4.4V, the commonly used carbonate-based electrolyte begins...

AI Technical Summary

Problems solved by technology

At present, the energy density of lithium-ion batteries is often increased by increasing the charge cut-off voltage, but there are also some problems at high voltages: when the voltage reaches 4.4V, the commonly used carbonate-based electrolyte begins to oxidize and decompose side reactions on the surface of the positive electrode material. , affecting the performance of lithium-ion batteries. At the same time, nickel-cobalt-manganese ternary materials will undergo irreversible H2-H3 phase transitions, resulting in excessive metal dissolution, intensified electrolyte side reactions, and increased battery gas production, which will lead to sudden decline in battery performance.

Especially at low temperature, the internal impedance of the lithium-ion battery increases, and the low-temperature discharge performance of the lithium-ion battery is obviously insufficient.

Images