What do you do with the batteries and the toxic materials inside when you're done with them (and how long do they last)?
What do you do with all the toxic materials produced during mining, refining, and production of batteries and materials?
How do you deal with these same issues as they affect solar panels, which are made of silicon?
No, that's not true. Most power comes from sources other than coal. Yes, coal is the largest single source but it is < 50% and decreasing every year.
2. There are no particularly toxic materials in the batteries. Landfills accept discarded lithium batteries as regular waste. While lithium is not currently economical to recycle, by the time the industry is as large as the lead-acid battery market (a very toxic product chain) it will be just as easy to recycle lithium.
3. What toxic materials are you referring to? I'm not aware of anything that stands out, especially compared to coal mining, or tar sands production, etc. Lithium mining in particular is a very similar process to the one that produces table salt from salt flats. The biggest problem is the use of water in areas that are very water-poor, ie the Atacama desert.
4. Silicon is non-toxic and inert. There are some hazards associated with dust particles during production, but those are easily handled by proper manufacturing processes. Perhaps you were thinking of thin-film solar panels, which may use e.g. Cadmium? They're less common and seem unlikely to displace silicon PV in the near future.
Water usage, along with the carbon emissions from the large diesel vehicles that are actually digging the stuff up.