The application belongs to the field of
new energy materials, and provides a preparation method of stannous
iodide, which comprises the following steps: adding hydriodic acid into
ultrapure water to configure a solution A; adding a
tin source into pure water, and then adding an
antioxidant to form a solution B; adding the solution A into the solution B, heating and reacting, and then adding a reaction catalyst, stirring, and obtaining an orange-red
solid; separating the orange-red
solid from a liquid, washing, and
vacuum drying to obtain a crude stannous
iodide; performing a first heating process on the crude stannous
iodide to separate the stannous iodide from oxidized impurities; and then performing a second heating process to obtain stannous iodide for
perovskite batteries through high-temperature purification; wherein the
tin source contains
divalent tin ions. The preparation method has mild
reaction conditions, simple
raw material acquisition and preservation, high reaction efficiency, and the prepared finished product has high quality and high purity and is not easy to be oxidized, and is used in narrow-bandgap
perovskite solar cells and laminated solar cells, and the
photoelectric conversion efficiency is significantly improved.