Hydrogen vs. Battery Electric Cars

There are also hydrogen internal combustion engines. Their only exhaust is also water.
Everything a battery is made of ultimately stems from hydrogen. So it just makes the most sense to use the most basic building block of the universe as our prime energy source. It's PLENTIFULLY available. We'll get better at extracting, isolating, and storing it with time.
Hydrogen internal combustion uses only one battery, like any internal combustion engine, simply to get the thing going. As such, it uses far less resources in regards to what is needed to manufacture batteries. Which, frankly, isn't a particularly environmentally friendly process. Nor is disposal of batteries. Also, hydrogen internal combustion is FAR more efficient than hydrogen fuel cells since it directly extracts the energy.
Yes, there are issues with the thermal characteristics of hydrogen internal combustion damaging metals, but modern alloys can handle it just fine. The biggest difficulty is storing the hydrogen in a state useful for internal combustion. But perhaps it can be stored in a different state and converted on-the-fly to its combustible form.