When earlier this year Tesla’s Elon Musk said the company could soon have batteries lasting for over one million miles, many probably took it as yet another grand promise with less substance than realism requires. Now it seems Musk may have not been exaggerating. Last month, Wired reported on a paper by researchers from Dalhousie University in Canada, which detailed a battery that “should be able to power an electric vehicle for over 1 million miles.” The researchers from Dalhousie University have an exclusive agreement with Tesla,…