Years of state support have made China the world’s battery powerhouse. Now, American firms are racing to close a decade-long gap in a sector vital to the clean energy transition. FREMONT, California: China has built an almost unassailable lead in the global battery industry, and analysts say the United States now trails by nearly a decade in a sector critical to the world’s clean energy transition. In the Californian city of Fremont, Amprius Technologies is one of several American companies