Tesla & GM 1Million Mile Battery - NVX to supply Graphite, Electrolyte & Cathode, page-499

Okay thanks@PieChart!
I guess that's why they're using Graphite in the Million Mile Batteries and not Silicon.

Also, i came across this article from the United Nations today regarding the push for more environmentally friendly EV Batteries. It's good to know that NVX have an alternative that isn't silicon but is still environmentally friendly (to an extent).

For anyone interested - link: https://news.un.org/en/story/2020/06/1067272

UNCTAD also recommends that the industry find ways to reduce its dependence on critical raw materials. For example, scientists are researching the possibility of using widely-available silicon, instead of graphite (80% of natural graphite reserves are in China, Brazil and Turkey).

If the industry manages to become less reliant on materials concentrated in a small number of countries, says UNCTAD, there is more chance that prices of batteries will drop, leading to greater take-up of electric cars, and a shift away from fossil-fuel powered transport.

As for the environmental consequences of the batteries themselves, the report recommends the development of improved, more sustainable mining techniques, and the recycling of the raw materials used in spent Lithium-Ion batteries, a measure that would help deal with the expected increase in demand, and also create new business opportunities.