Key Takeaways POSCO Future M invested in a solid-state battery firm, strengthening a partnership tied to a November MOU.Factorial's Solstice offers higher energy density and safety, with automaker partnerships across key regions.POSCO will optimize coatings and expand into sulfide electrolytes and advanced anode materials.POSCO Holdings Inc.’s (PKX) unit POSCO Future M has invested in a U.S.-based all-solid-state battery company, Factorial, further strengthening the partnership that was entered into followi ...