Cardi's lawyers, Drew Findling, David Chesnoff and Richard Schonfeld, tell TMZ, "This afternoon we were notified by the Las Vegas Metropolitan Police Dept., that as a result of their investigation, there will be NO charges against Cardi. On behalf of Cardi, we appreciate the Las Vegas Metropolitan Police Dept's diligent and prompt resolution of this matter."

As you know, Cardi was performing at Drai's Beachclub last Saturday when she asked the crowd to splash water on her to cool her down in the burning Vegas heat ... but when someone threw a cup with an unknown liquid and ice, she hurled the mic at the person. It ricocheted and hit another person, who filed a police report.

Cardi was then listed as a battery suspect but the case has gone nowhere. It was never ever referred to the D.A. The cops concluded Cardi did not commit a criminal offense.

We learned an audio production company that owns the mic decided to auction off the piece, with the money going to charities like the Wounded Warrior Project and Friendship Circle Las Vegas, which helps teens and young adults with special needs. FYI, the bids have hit $100,000.