A kind of electrolytic solution and lithium ion battery

Abstract

The invention provides an electrolyte solution and a lithium ion battery. Lithium dioxalate borate (LiBOB) and a cyano-containing pyridyl compound shown in Formula 1 are added to the electrolyte, wherein the cyano-containing pyridyl compound shown in Formula 1 can be combined with the cyano-containing pyridyl compound contained in the electrolyte The ester group is chelated and forms a tough protective network on the surface of the positive electrode, which inhibits the decomposition and gas generation of LiBOB at the positive electrode. At the same time, because LiBOB forms high impedance at the negative electrode, it is more stable and more conducive to the formation of SEI film with high temperature performance , the two compounds together form a strong protective film on the surface of the positive and negative electrodes, and the solvent contains low-viscosity n-propyl propionate, the addition of the n-propyl propionate is more conducive to ion conduction, further improving the power of the electrolyte It improves the chemical performance, reduces the battery impedance, and makes the movement of lithium ions smooth, thus significantly improving the high and low temperature performance and safety performance of the battery.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and in particular relates to an electrolyte and a lithium-ion battery. Background technique [0002] In recent years, with the rapid development of electronic products such as smart phones, tablet computers and smart wearables, consumers have more and more requirements for the energy density and use environment of lithium-ion batteries, considering the length of use of electronic products and the difference in working environment. At the same time, with the phenomenon of global warming, this requires lithium-ion batteries to have excellent high and low temperature performance. [0003] At present, the improvement of the energy density of lithium-ion batteries is mainly achieved by using high-voltage lithium cobaltate cathode materials of 4.4V and above and graphite anode materials with high capacity and high compaction density. However, as the voltage of lithium-ion batteries increas...

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Problems solved by technology

[0005] The object of the present invention is to provide an electrolyte and a lithium ion battery in order to solve the problems of existing lithium-ion batteries, such as difficulty in balancing high and low temperature performance, and poor safety performance. The battery has excellent high and low temperature performance and safety performance

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