https://www.news.com.au/finance/business/mining/harvard-professor-explains-heartwrenching-source-of-electric-vehicle-iphone-batteries/news-story/db881f47c76db89581409c092a740c4c
another reason why vanadium is 'cleaner' than lithium. The focus in the talk is more on batteries in phones and electric cars (as that's more relevant to the everday consumer) but the horrific conditions in the Congo's cobalt mines is a big tick for large scale vanadium batteries over lithium.