Lithium batteries can be dangerous, in more than one way. Lithium reacts intensely with water, forming lithium hydroxide and highly flammable hydrogen. The batteries themselves can be a fire and explosion hazard. All you have to do is search YouTube for some experiments with common lithium batteries to see. Some react violently to overcharging/heat and also to mechanical failure.
To be fair, gasoline is highly flammable and explosive as well, in the right conditions. But, fuel tanks are generally empty when transporting cars by ship or air.
In any case this ship is probably going to suffer a good loss of a lot of the cargo--hard to say how they'll contain it or deal with the remaining cargo.
I was surprised that the destination was not the port of New Jersey/New York, Baltimore, Savannah or Charleston, but Davisville, Rhode Island. Yeah, I had not heard of it either!