Lithium mining, as with the mining of any mineral, can be harmful to the environment if not done with proper safeguards.
On balance, however, lithium batteries are much less harmful to the environment than the devastation caused by conventional internal combustion engines.
Batteries containing lithium replace a staggering range of toxic and damaging substances--fracking fluids, refinery pollution, crude oil leaks, gasoline and diesel fuel, MTBE and other additives, oil lubricant, transmission fluid, grease, lead batteries, and vehicle air pollutants in the form of particulates, NOx, VOCs, and greenhouse gases.
Also, electric vehicles tend to use electromagnetic brakes so energy can be recovered, reducing the use and general dispersion of hazardous asbestos and other brake materials on and near roads.
Lithium itself is only about 1% to 2% of the weight of a lithium battery. A Tesla Model S contains about 12 kilograms of lithium. Also, unlike a lead battery where the lead is exposed to the outside through the posts, posing a direct hazard to the environment and anyone who handles it, the lithium is sealed inside the battery and is not exposed to the elements.
Consumer applications for lithium such as cellphone and laptop batteries use more than twice the lithium used by electric cars. It is estimated that about 2/3 of lithium batteries will be recycled.
In coming years, it is expected that new batteries not containing lithium will eventually supplant lithium batteries.
Lithium is often scapegoated by advocates for the current fossil fuel system as a reason to preserve the status quo. Upon careful analysis, however, the environmental harms caused by production of electric vehicles are much less than those caused by gasoline and diesel, and should not stand as a barrier to the phasing out of internal combustion engine vehicles.