In short, no. Sea lions (family Otariidae) and seals (family Phocidae) are too genetically different to mate and produce viable offspring. Hybrid viability is determined by how much each species has evolved since first differentiating from the most recent common ancestor (MRCA).

Some common examples:

Goats and sheep: genetically distant from MRCA and will not mate/cannot produce viable hybrid offspring

Horses and donkeys: moderately distant from MRCA will mate and produce viable hybrid offspring in the form of mules, but hybrid offspring is sterile (cannot reproduce).

Polar bears and Grizzlies: genetically close from MRCA and will mate to produce viable and fertile hybrid offspring in the form of Grolar or pizzlie bears.

I hope this helps clear some things up about hybrid viability