Low-temperature electrolyte taking ethyl fluoroacetate as solvent and application of low-temperature electrolyte

Abstract

The invention belongs to the technical field of electrochemistry, and particularly relates to a low-temperature electrolyte taking ethyl fluoroacetate as a solvent and application of the low-temperature electrolyte. According to the low-temperature electrolyte, fluoroethyl acetate and derivatives thereof are used as solvents, lithium salt, sodium salt or quaternary ammonium salt is used as solutes, and the low-temperature electrolyte further comprises a cosolvent and an additive. Compared with the traditional electrolyte, the low-temperature electrolyte disclosed by the invention still shows higher ionic conductivity at lower temperature (minus 80 DEG C). Under the electron withdrawing action of fluorine atoms, fluoroethyl acetate and positive ions have lower desolvation energy, the desolvation process is promoted, and the intercalation and deintercalation of ions at the low temperature are facilitated. When the electrolyte provided by the invention is applied to a lithium ion battery,a sodium ion battery, a supercapacitor and a hybrid supercapacitor, the system shows excellent specific capacity, cycle performance and power performance at low temperature.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a low-temperature electrolyte and its application. Background technique [0002] As the speed of fossil energy consumption on the earth continues to accelerate, environmental problems have become increasingly prominent. Therefore, searching for an efficient, clean, safe and renewable new energy source has become a research focus of scientists from all over the world. Since the commercialization of secondary batteries, they have been widely used in more and more fields, but with the continuous upgrading of requirements, such as special needs in military equipment, aerospace and other fields, the secondary batteries used today are becoming more and more These requirements cannot be met due to the limited temperature range. For example, a lithium-ion battery can only release 12% of its rated capacity at room temperature under the condition of minus 40 degrees,...

AI Technical Summary

Problems solved by technology

Since the commercialization of secondary batteries, they have been widely used in more and more fields, but with the continuous upgrading of requirements, such as special needs in military equipment, aerospace and other fields, the secondary batteries used today are becoming more and more are limited by the temperature range to meet these requirements

However, these low-temperature batteries cannot be charged and discharged at low temperatures, and can only be discharged at low temperatures after being charged at room temperature, which greatly limits their practical applications.

Moreover, none of the commercially used high-energy intercalation compound electrode materials can be applied at low temperatures, resulting in the low energy density of most low-temperature batteries, which is also the main problem facing low-temperature batteries at this stage.