LG Energy Solution has started mass production of lithium iron phosphate (LFP) battery cells at its US joint venture plant with General Motors, accelerating its push into the fast-growing North American energy storage systems market. According to the joint venture Ultium Cells on Tuesday, the commercial rollout comes about four months after the company announced plans to invest roughly $70 million to convert part of its Tennessee plant’s production lines to manufacturing LFP batteries for ESS. T