Lithiun Ion Battery Caution
I am sure that any Li battery sold for automotive use in the future will be safe.
Electric cars are using them now, and have been for 10 years. Very few issues.
I had a lead acid battery blow it's top off seconds after starting a commuter van I was refueling. Lucky the hood was down.
Bad thing happen when you store mass amounts of energy in ever smaller packages, not just Li batteries.