Which country has over 50% of global reserves of cobalt, a key mineral used in lithium-ion batteries?

The Democratic Republic of Congo (DRC), the second-largest country in Africa, has vast reserves of precious metals and gems. But despite its wealth of resources, it has been ranked for several years as having the lowest GDP per capita in the world at 418 USD, which is 3% of the average per-capita GDP of all the world's nations. The DRC is a country blighted by 20 years of civil war and multiple Ebola outbreaks.

Extreme poverty has driven families in the DRC to withdraw their children from schools to work in unregulated small-scale mines which employ an estimated 12 million Congolese. In mid-December 2019, a human rights NGO, International Rights Advocates, filed legal action in Washington DC against Apple, Google, Dell, Microsoft and Tesla who are accused of being complicit in the deaths of child laborers due to economic pressures for cheap cobalt. The case was filed on behalf of the families of 14 children, one only 6 years old, who were killed in a cobalt mine tunnel collapse.