Contemporary Amperex Technology Company (CATL), the world’s largest maker of electric vehicle (EV) batteries, aims to be a leading technology provider in China’s green energy sectors as it prepares to complete the world’s biggest stock offering so far this year. The group last year established CharGo to develop mobile storage and charging and testing robots for EVs to diversify its business. The robots can be used wherever EV charging piles or stations are lacking, fully occupied or out of...