Local high-concentration electrolyte, preparation method thereof and battery

The invention discloses a local high-concentration electrolyte, a preparation method thereof and a battery, and relates to the technical field of batteries. The local high-concentration electrolyte comprises a lithium salt, a solvent and a diluent, the solvent comprises a carbonic ester compound, a fluoro carbonic ester compound and a silane compound, and the silane compound comprises one or more of dimethoxydimethylsilane, diethoxydimethylsilane and trimethoxymethylsilane. According to the local high-concentration electrolyte, lithium salt can be dissolved by carbonic ester and fluoro carbonic ester, and ions are promoted to flow between the positive electrode and the negative electrode of the battery; the silane compound is stable to heat and chemical reagents, can improve the stability of the local high-concentration electrolyte and effectively improve the high-temperature resistance and high-voltage resistance of the local high-concentration electrolyte, and the silane compound is low in impedance, can in