The invention provides a
lithium battery electrolyte additive and a preparation method thereof, and relates to the technical field of
lithium batteries. The preparation method comprises the following specific steps: S1, adding a multi-walled
carbon nanotube and polydopamine into an
ethanol solution of
malic acid, carrying out ultrasonic treatment, filtering, and calcining in an
inert atmosphere to obtain a pretreated
carbon nanotube; s2, adding the pretreated carbon nanotubes into absolute ethyl
alcohol, adding
tannic acid, and performing
microwave treatment to obtain
modified carbon nanotubes; s3,
graphene is added into absolute ethyl
alcohol,
melamine is added, ultrasonic treatment and
filtration are performed,
calcination treatment is performed in an
inert atmosphere, and modified
graphene is obtained; and S4, adding the
modified carbon nanotube in S2 and the modified
graphene in S3 into absolute ethyl
alcohol, mixing, and carrying out rotary
evaporation to remove the
solvent, thereby obtaining the target
electrolyte additive. Through cooperation of the
modified carbon nanotubes and the modified graphene, consumption of an
electrolyte and active
lithium in the cycle process is greatly reduced, the cycle life of the
lithium metal battery is remarkably prolonged, the safety performance of the
lithium metal battery is remarkably improved, and the application prospect is good.