The invention relates to a preparation method of positive active material hollow spherical 
lithium manganate of a 
lithium ion battery, and belongs to the technical field of a chemical battery. The method comprises the steps of uniformly mixing a 
manganese sulfate aqueous solution with a 
potassium persulfate aqueous solution, adding concentrated 
sulfuric acid, carrying out 
hydrothermal reaction, then centrifuging the 
mixed solution, taking out 
solid phase, and washing and 
drying the 
solid phase to obtain spinous hollow 
manganese dioxide spheres; mixing soluble 
lithium salt and the spinous hollow 
manganese dioxide spheres to obtain a mixture I, ultrasonically 
processing, 
drying and burning the mixture I to obtain hollow spherical lithium 
manganate. The prepared spherical lithium 
manganate belongs to a 
spinel type, the 
diameter of the spherical lithium manganate is 0.5 to 5 micrometers, the degree of 
crystallinity is good, the spherical lithium manganate is mainly formed by clustering and assembling spinous nanowires, a large clearance is formed between two adjacent nanowires, a porous structure is formed inside the spherical lithium manganate, the 
lithium atom density is reasonable, the activity is low, the 
chemical stability is high, adequate contact when the lithium salt is dissolved and the lithium manganate is synthesized in the later period can be facilitated, the 
insertion and separation of lithium ions can be facilitated, and the electrochemical 
cycling reversibility and stability of the 
lithium ion battery can be effectively improved.