Nanocomposite gel electrolyte, lithium secondary battery and preparation method of lithium secondary battery

The invention relates to nanocomposite gel electrolyte, a lithium secondary battery and a preparation method of the lithium secondary battery. The gel electrolyte is prepared by the steps: introducinghydrophobic modified nanoparticles into liquid electrolyte, and forming a three-dimensional network by using hydrogen-bond interaction among the hydrophobic modified nanoparticles and surface modified molecules thereof and electrolyte solvent molecules, so as to enable gelation of the liquid electrolyte. The ionic conductivity of the gel electrolyte is close to that of electrolyte of the same type and is about 10 S/cm. According to the addition of the hydrophobic modified nanoparticles, the lithium-ion transference number of the electrolyte can be effectively improved, and the interface impedance between the electrolyte and the lithium metal is reduced. In addition, compared with the pure electrolyte of the same type, the gel electrolyte has excellent compatibility with a lithium metal electrode and good cycl