Environment-friendly purification method of allyl-1,3-sultone

The invention belongs to the technical field of lithium battery electrolyte additives and particularly relates to an environment-friendly purification method of allyl-1,3-sultone. The method comprises the following steps: (1) adding an allyl-1,3-sultone crude product into solvent water, heating to 25-75 DEG C, and stirring to dissolve, wherein the mass ratio of the allyl-1,3-sultone crude product to water is (1 to 20)-(1 to 10); (2) adding activated carbon into a water solution obtained in the step (1) for decoloration, and immediately filtering, so as to obtain filtrate; (3) cooling the filtrate obtained in the step (2) to 0-15 DEG C so as to separate out crystals, and separating to obtain the crystals and a mother solution; and (4) drying the crystals obtained in the step (3) at 0-82 DEG C, so as to obtain allyl-1,3-sultone finished product. The equipment and the process required in the method are relatively simple, allyl-1,3-sultone does not need to be purified by virtue of an organic solvent, the method can be matched with multiple cyclic purification, and the purification process is easy to industrialize, so that the environment-friendly purification method is simple and feasible.