Low-temperature-resistant and high-temperature-resistant non-aqueous electrolyte and lithium ion battery

Abstract

The invention relates to a low-temperature-resistant and high-temperature-resistant non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte comprises an electrolyte lithium salt, a non-aqueous solvent, a first additive and a second additive, the first additive comprises a compound represented by a formula (I) and / or a compound represented by a formula (II), and the second additive comprises tris (trimethylsilane) phosphate, wherein structural formulas (I) and (II) are shown in the specification respectively, R and Y are independently selected from hydrogen, a C1-C5 saturated alkyl group, a C1-C5 unsaturated alkyl group, a C1-C5 alkoxy group, halogen or a C6-C18 aryl group.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a low-temperature and high-temperature-resistant non-aqueous electrolyte and a lithium-ion battery. Background technique [0002] Electrolyte is one of the four key materials of lithium-ion batteries. It is called the "blood" of lithium-ion batteries. Its function is to conduct electrons between the positive and negative electrodes in the battery. It is also the reason for lithium-ion batteries to obtain the advantages of high voltage and high specific energy. Important guarantee. Electrolytes used in lithium-ion batteries should generally meet the following basic requirements: 1. High ion conductivity, generally should reach 1×10 -3 ~2×10 -2 S / cm; 2. High thermal and chemical stability, no separation in a wide voltage range; 3. Wide electrochemical window, maintaining stable electrochemical performance in a wide voltage range; 4. It has good compatibility with other parts o...

AI Technical Summary

Problems solved by technology

[0003] At present, people have conducted a series of researches on high-temperature resistant electrolytes. In order to improve high-temperature performance, additives such as vinylene carbonate and ethylene carbonate are generally used. However, these additives will cause large battery impedance, and it is difficult to balance capacity, Balance of other electrochemical properties such as internal resistance

In order to improve the low-temperature performance of the battery, carboxylic acid esters with low melting points such as ethyl acetate and ethyl propionate are generally selected as the main solvent of the electrolyte, but these solvents have relatively low boiling points, which are not good for the high-temperature performance of the battery.

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