Electrolyte liquid with fast charging and ultralow-temperature discharging performances and lithium ion battery

Abstract

The invention belongs to the technical field of lithium ion batteries, and discloses electrolyte liquid with fast charging and ultralow temperature charging performance and a lithium ion battery. The electrolyte liquid comprises a solvent, an electrolyte and an additive; the solvent comprises ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate and propylene carbonate in a mass ratio of 1: 1: 1: 0.5; the electrolyte comprises lithium hexafluorophosphate and lithium tetrafluoroborate in a mass ratio of 1: 0.5, and the molar concentration of the electrolyte is 1mol / L; and the additive is silicon nitride, and the mass concentration of the silicon nitride is 0.1%. The additive silicon nitride is added into the electrolyte liquid disclosed by the invention, so that the thermal shock resistance of the battery can be improved, and the performance of the battery can be kept stable at high and low temperatures, so that the fast charging and ultralow-temperature discharging performances are both considered. The battery provided by the invention can be fully charged within 15 minutes, the discharging efficiency at -20 DEG C is greater than 80%, the discharging efficiency at -50 DEG C is greater than 60%, and the use requirements in frigid regions are met.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to an electrolyte solution and a lithium-ion battery that take into account fast charging and ultra-low temperature discharge performance. Background technique [0002] Lithium-ion batteries, with their high energy, high battery voltage, wide operating temperature range, long storage life, no memory effect, small self-discharge rate, fast charge and discharge, etc., are widely used in mobile phones, notebook computers, digital cameras and other electronic devices. Among the products, it is also widely used as a power battery in electric bicycles, model airplanes, and electric vehicles. [0003] The fastest charging speed of traditional lithium-ion batteries is about 1 hour at room temperature, while the discharge efficiency at low temperature (minus 20°C) is very low, about 50%, and low temperature (minus 40°C) basically cannot discharge normally, thus limiting the lit...

AI Technical Summary

Problems solved by technology

[0003] The fastest charging speed of traditional lithium-ion batteries is about 1 hour at room temperature, while the discharge efficiency at low temperature (minus 20°C) is very low, about 50%, and low temperature (minus 40°C) basically cannot discharge normally, thus limiting the lithium-ion battery. Application Range of Ion Batteries