Will EV battery technology be safe for driver/passenger and first responders in case of a serious accident? There's always a trade off.
Lithium is a metal that burns at insane temperatures. LI batteries were avoided for decades because they would burst into flames if overcharged or discharged too quickly. Adding microprocessors to regulate charge and discharge has solved this issue, but in the case of a breach in an accident, an LI battery is extremely dangerous. You can't put them out with water. They need to be smothered.