They are talking about cobalt from coltan - cobalt-tanatalum - ore, 70% of which is used in vehicle and device batteries. Not solar panels. Your article you linked contained the word "solar" and none of them were related to child mining of coltan for solar panels.

They did allude to energy storage in batteries for wind and solar sources, and if you look there are a number of research projects to reduce cobalt consumption in grid scale storage and other battery cathode applications.

Your summary of the article is misleading and incorrect.