▎ 摘　　要

NOVELTY - A molybdenum diselenide nano-sheet prepared based on ultrasonic spray pyrolysis, has a spherical shape with a diameter of 500 nm to 1 microm, a low number of layers of 5-10 layers, and a layer of large interlayer spacing in excess of 0.7 nm. USE - Preparation of molybdenum diselenide nano-sheet used for cathode material of lithium ion battery used in battery device. ADVANTAGE - The molybdenum diselenide nano-sheet has ball shape, low layer number, large interlayer distance, high discharge specific capacity, and can keep good cycle stability. The method has simple operation, high repeatability, low cost and large yield. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a preparation method of molybdenum diselenide nano-sheet prepared based on ultrasonic spray pyrolysis, comprising fully dissolving molybdate and hexamethylenetetramine in solvent, mixing uniformly the obtained solution as precursor solution is placed in the ultrasonic atomizing chamber of ultrasonic spray pyrolysis system, setting the atomizing power, carrier gas flow rate and pyrolysis temperature for ultrasonic spray pyrolysis to obtain calcined precursor; and calcining the precursor with selenium powder at high temperature, where calcining atmosphere is argon and hydrogen mixed atmosphere; and (2) a preparation method of cathode material of lithium ion battery.