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uni'wissen 01-2012_ENG

Prof. Dr. Ingo Krossing studied chemistry at the Ludwig-Maximilian Univer- sity of Munich, where he also went on to earn his PhD in inorganic chemistry. He then conducted research for two years at the Univer- sity of New Brunswick, Canada. Afterwards, he completed his habilitation at the University of Karls­ ruhe, remained there for two more years as a lec- turer, and then accepted a position at the Swiss Fed- eral Institute of Technology in Lausanne, where he served for two years as an assistant professor. Since 2006 he has held the chair in molecular and coordina- tion chemistry in Freiburg. His research focuses ­primarily on charged sys- tems and the computer- aided synthesis of cations and anions. Krossing is a senior fellow at the Frei­ burg Institute for ­Advanced Studies (FRIAS) and a member of the Freiburg ­Materials Research Center (FMF). Further Reading- Trapp, N./Krossing, I. (2009): Chemie mit schwach koordinierenden Anionen: Exotisch­ es und Nützliches. In: Nachrichten aus der Chemie 57/6, pp. 632. Krossing, I./Raabe, I. (2004): Noncoordinating anions – fact or fiction? A survey of likely ­candidates. In: Angewandte Chemie Inter­ national ­Edition 43/16, pp. 2066–2090. At one point he was approached by the ­company Merck, which specializes in battery electrolytes. “They said: You’re already doing this stuff anyway. Don’t you have anything we can use?” This is when Krossing and his team started ­developing electrolytes for batteries. “The transitions between the electrodes and the electrolytes are an important aspect, so close cooperation and exchange with the materials ­researchers who develop the electrodes is very important.” This fact was also taken note of by BASF, which had previously produced cathode materials for lithium-ion batteries, then decided to launch ­activities in the area of electrolytes, and finally ended up buying out Merck’s electro­ lyte division. However, the chemical giant has decided to ­continue the cooperation with Kross­ ing’s department. Althogh Ingo Krossing has already found ­another promising new electrolyte, it will be 10 to 15 years before it flows in the tanks of the future. There are still many hurdles to overcome on the path from the laboratory at the Materials ­Research Center to serial production: tests, ­approval procedures, bureaucracy. So what is this new electrolyte? “That, of course, is some­ thing I can’t reveal.” The available electrons rush with a tremen- dous amount of energy from the anode to the cathode. However, the separator prevents them from flowing directly to the cathode. They can only travel from the negative to the positive pole over an external circuit. In doing so, they give off energy with which they, for example, light up a lamp along the way – this is the bat- tery’s electrical current. Whenever an electron flows, a lithium atom gives off an electron, ­mediated by the graphite coating, thus feeding the copper. In this way, the amount of elec- trons – and thus also the voltage in the copper conductor – remains constant. The lithium atom loses the energy that is available to the electron in order to illuminate the lamp. A posi- tively charged lithium ion remains. In contrast to the electron, it can pass through the separator and travel through the electrolyte directly to the cobalt oxide. When all of the lithium atoms have separated from their electrons and have reached the positive pole, the battery is empty: The cobalt atoms in the cobalt oxide have ­absorbed the electrons, and the positively charged lithium ions have caused the cathode to be converted into lithium cobalt oxide. When an opposing voltage is applied, the process is reversed: Electrons and lithium ions travel back by separate paths and meet again in the graphite. The battery is recharged. III. 35