Electrolyte additive, application of electrolyte additive, single-particle graphite negative electrode electrolyte and application of single-particle graphite negative electrode electrolyte

The invention relates to the technical field of lithium ion batteries, and discloses an electrolyte additive and an application thereof, and a single-particle graphite negative electrode electrolyte and an application thereof, the electrolyte additive contains a p-fluorobenzonitrile compound and a substance A, and the substance A is tris (pentafluorophenyl) borane and/or tris (pentafluorophenyl) phosphine; the dosage mass ratio of the p-fluorobenzonitrile compound to the substance A is 1: (0.1-0.5). According to the electrolyte additive provided by the invention, the wettability of a single-particle graphite negative electrode electrolyte can be remarkably improved, a highly-stable single-particle graphite negative electrode interface is formed, the impedance of a negative electrode is reduced, and the cycle performance and the rate capability of the negative electrode are improved. The cycle life and the rate capability of a total battery adopting the single-particle graphite negative electrode electrolyte p