In fact, there was a Science Versus podcast about the benefits of lithium in public drinking water. Lithium naturally occurs in some water sources more than others, and areas with more lithium in the water have better mental health.

If you ever visit Ashland, Oregon—famous for its Shakespeare Festival and chill vibes—you’ll have a chance to drink from their “lithia fountain” at the heart of downtown: https://www.trover.com/d/95b7-lithia-water-fountain-ashland-...

Interesting!

What are the effects of too much lithium though?

(To answer myself, from Wikipedia..) >Common side effects include increased urination, shakiness of the hands, and increased thirst.[2] Serious side effects include hypothyroidism, diabetes insipidus, and lithium toxicity.[2] Blood level monitoring is recommended to decrease the risk of potential toxicity.[2] If levels become too high, diarrhea, vomiting, poor coordination, sleepiness, and ringing in the ears may occur.[2]

Plus they are already pretty recyclable unlike plastic. Really lithium is probably one of the 'cleanest' materials we've had for batteries given that they aren't mostly heavy metal like NiCad or Lead-Acid.

However cobalt isn't something you want in your garden!

There is quite a bit of R&D going into negating the need for Cobalt in Li batteries. I would not expect Cobalt to be needed in ~3-5 years (for Li batteries).

Lithium Iron Phosphate is an already-viable chemistry that has a lot of upsides and only a few downsides compared to Lithium Cobalt.

https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

The tl;dr is slightly lower energy density (~14%) in exchange for non-toxicity, extremely low self-discharge rates, not prone to runaway thermalling, and great cycle life.

It also has the advantage of being able to be essentially a drop-in replacement for many lead-acid uses.