Without them, today's mobile phones, mp3-players, notebooks and electric vehicles would be unthinkable: Lithium-Ion Batteries. But how do they work? What do they consist of? How are they manufactured? -- Scientists from the Institute for Applied Materials (IAM-WPT) at the Karlsruhe Institute of Technology (KIT), a partner of the knowledge and innovation community KIC InnoEnergy, give an answer to these questions in this video.