Automotive giant Ford is shoring up its battery supply chain — partly by importing lower-cost, iron-based batteries popular in China — as it sprints to increase electric vehicle production.Why it matters: Employing cheaper, safer and more durable iron batteries could accelerate demand for mass-market electric vehicles (EVs), and help automakers sidestep nickel and cobalt supply problems that have been driving up EV prices.The big picture: Carmakers’ plans to shift away from gasoline-powered vehicles won’t succeed unless they can secure reliable battery supplies. But with raw materials in short supply — and sourced primarily in Asia — the battery race is turning into a fierce geopolitical competition. Driving the news: Ford said Thursday it had lined up enough batteries to meet its short-term goal of producing 600,000 EVs annually by 2023, up dramatically from the 27,140…