Tata Group’s battery unit is gearing up to make cells using its own technology for the first time as China’s tighter curbs spur the Indian conglomerate to seek self-sufficiency, according to people familiar with the matter. The closely held Agratas Energy Storage Solutions Pvt. is building a pilot production line of lithium iron phosphate, or LFP, cells at its upcoming battery factory in Sanand in the western state of Gujarat in India, said the people, who asked not to be identified discussing the company’s internal decisions.