Predominately recycled Lead will have substantially lower CO2...

Predominately recycled Lead will have substantially lower CO2 emissions per KwH of battery capacity compared to Lithium for quite awhile, due to most Lithium supply needing to be mined milled and refined (lots of CO2). In addition because of it's capacity to explode, Lithium doesn't have a great deal of recycling capacity yet (the need for more lithium to be mined/more CO2)

Conclusion - there's nothing clean about Lithium, nor anything else that has to come out of the ground. And by default the wind turbines, solar panels & electric cars, that the stuff goes into

but what's the alternative??