Summary:

The invention discloses a lithium-ion battery electrolyte with negative electrode targeted passivation, comprising lithium salt, a first-phase solvent, a passivating agent, and a second-phase solvent; The lithium salt is dissolved in the first phase solvent and insoluble in the second phase solvent, and the passivator is dissolved in the second phase solvent and insoluble in the first phase solvent, and the first phase solvent and the second phase solvent are miscible to form a macroscopic homogeneous and microscopic phase splitting solution system. The passivator can initiate ring-opening polymerization by lithium or lithium metal. When the negative electrode SEI film is broken to expose the negative electrode graphite, the passivator is precisely oriented to the crushed position to open the ring to form a film, repair the damaged SEI film, and prevent the continuous reaction between the electrolyte and the negative electrode. When the SEI film is completely decomposed and broken due to the continuous rise of temperature, the polymer film generated by the ring-opening polymerization of the passivator can replace the SEI film, block the exothermic side reaction between the electrolyte and the negative electrode, reduce the initial heat accumulation during thermal runaway, delay or avoid the occurrence of thermal runaway of the battery, and improve the safety of the battery.

Link: http://epub.cnipa.gov.cn/patent/CN115051032A?8kt2YOWWXQBD=1669778859841