Rare earth halide solid electrolyte and preparation method and application thereof

The invention discloses a rare earth halide solid electrolyte and a preparation method and application thereof, the rare earth halide solid electrolyte is characterized in that the chemical general formula of the rare earth halide solid electrolyte is LiaYBra + 3-bXb, X is Cl or I, when X is Cl, 2.5 < = a < = 3, 0 lt; blt; 1.5 parts; when X is I, 2.5 < = a < = 3, 0 lt; b < = 3; and the values of a and b satisfy 2b < = a + 3. According to the material, the room-temperature lithium ion conductivity of Li3YBr6 is remarkably improved, and meanwhile, the reduction stability of Li3YBr6 is effectively improved. 本发明公开了一种稀土卤化物固态电解质及其制备方法与应用，其特征在于，其化学通式为LiaYBra+3-bXb，其中X为Cl或I，当X为Cl时，2.5≤a≤3，0