High-voltage lithium-ion battery electrolyte silicon-based pyridine additive, electrolyte and battery thereof

Abstract

The invention discloses a silicon-based pyridine additive for a high-voltage lithium-ion battery electrolyte, an electrolyte and a battery thereof. The electrolyte additive for a high-voltage lithium-ion battery provided by the invention is an acetylene-silyl-pyridine compound, and the acetylene-silyl-pyridine compound passes through an electric Chemical polymerization forms on the surface of positive and negative electrodes with high electronic conductivity (RC 2 Si) n Organic and inorganic products containing -C=C-C=C- and N-containing elements, wherein the pyridyl functional group can also inhibit the dissolution of transition metal ions in the positive electrode and the damage of transition metal ions to the negative electrode interface film, and Si As a core group, through the anchoring effect of Si element, the product composition in the interface film is stabilized, avoiding complete oxidative decomposition and continuous side reactions under high voltage, protecting the interface film of the positive and negative electrodes, and inhibiting the side effects of the electrolyte. reaction, thereby reducing the impedance of the battery and improving the cycle performance of the high-voltage battery.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a silicon-based pyridine additive for a high-voltage lithium-ion battery electrolyte, an electrolyte and a battery thereof. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, high specific power, high conversion rate, long life, and no pollution, and have been rapidly popularized. Their applications have gradually shifted from portable electronic products and communication tools to the power supply field. The lithium battery industry has a good According to the development trend, the production capacity of lithium-ion batteries has reached 198GWh in 2019, and it is estimated that by 2030, the production capacity will reach 3392GWh, an increase of nearly 17 times. [0003] However, with the expansion of science and technology and application fields, higher requirements are placed on the energy density and cycl...

AI Technical Summary

Problems solved by technology

However, under high voltage, the halogenated pyridine cannot stably form a stable interfacial film on the interface between the positive and negative electrodes, and it will continue to oxidize and decompose, causing side reactions and deteriorating battery performance.

[0006] Publication number "CN108321433A", the patent titled "An electrolyte additive and electrolyte for improving the low-temperature performance of lithium-ion batteries" discloses an electrolyte additive and electrolyte for improving the low-temperature performance of lithium-ion batteries. The pyridine of the group is used as an additive to improve the low-temperature performance of the lithium-ion battery. Through the negative charge tendency of the nitrogen atom in the pyridine, it forms a synergistic effect with the lithium salt to improve the ionic and electronic capabilities of the electrolyte, and at the same time utilizes the hydrophobicity and hydrophilicity of the alkyl group. The imine group reduces the surface tension of the electrolyte and improves the wettability of the electrolyte, thereby improving the low-temperature cycle performance of lithium-ion batteries. Although this patent can improve the performance at low temperatures, at high voltages, especially at high temperatures, The additive will also have a continuous oxidation-reduction side reaction, causing battery deterioration

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