The Democratic Republic of Congo is preparing to more than double a tax on two-thirds of global cobalt supply, potentially increasing the cost of the critical battery metal just as the world begins to embrace electric vehicles. Congo, the world's biggest cobalt producer, will increase the royalty miners pay on exports of the metal to 5% from 2% if it opts to categorize cobalt as a "strategic substance," Mines Minister Martin Kabwelulu told the country's Senate last week.Read full news