Environmentally it’s more about how you extract lithium from the lithium rich brines, for instance, in South America they use massive evaporation ponds which look horrible at least.
In Cornwall they’re proposing combined geothermal & lithium extraction plants. Geothermal has been tried before but had the probem that the salts came out of solution & blocked up the pipework, the lithium rich salts being a major problem as a process pollutant, but 40 years later & the pollutant has become the ore. The geothermal “fluids” are pretty acidic though & they’d be injected back into a parallel borehole. Depths of around 4km plus are being talked about & the souce rocks are the granite batholiths (granitic pegmatites are rich in spodumine & other lithium rich minerals, the geology & chemistry of how they formed is simple enough & you could talk about “eutectic points”).
Open mining for spodumine in Canada would be just like any other quarrying operation, and the processing acidic & just as dirty as other mineral extraction.
What differs with fossil fuels is that the extraction & pollution simply keeps going & in far larger amounts, recent quotes were saying that lithium battery cars became less polluting overall than fossil fueled cars after around 16,000 miles of use.
Lithium batteries can be & will be 100% recycled so there is no “disposal”. The fuel, electrons, will hopefully continue to be extracted by wind turbines etc., in a more environmentally acceptable manner than burning hydrocarbons.
Other environmental concerns such as particulate pollution from tyres (wheelchair tyres are probably more polluting) and dust from brakes (regenerative braking doesn’t use the brake pads so no dust) are usually brought up simply as excuses for carrying on polluting the planet with fossil fuels, or, political stunts by people who don’t believe in personal transport & who would prefer the disabled were euthanased.