锂空气电池可能成为下一代新电池技术

Rechargeable lithium air batteries are a next-generation technology: Theoretically they might be much lighter and offer better performance than current lithium ion batteries. However, currently they run out of steam after only a few charging cycles. Researchers at the Technical University of Munich (TUM) and the Forschungszentrum Jülich have now investigated the processes and discovered a possible culprit: highly reactive singlet oxygen, which is released when the batteries are charged. A trimming diet is in order: Cell phones still bulge from jacket pockets and laptop computers continue to overstrain shoulder muscles. To blame are primarily the batteries: The ubiquitous lithium ion batteries need heavy electrodes made of transition metal oxides.

Light-weight alternatives are thus sought after. "One of the most promising approaches is the lithium air battery in which the lithium cobalt oxide cathode is replaced by carbon particles," explains Johannes Wandt, doctoral candidate and member of Prof. Hubert Gasteiger's team in the Department of Technical Electrochemistry at TUM.

"The theoretical energy density of these new rechargeable batteries is significantly higher than that of traditional lithium ion batteries:" Unfortunately, the technology is not yet ready for everyday use because rechargeable lithium air batteries have only a very short lifetime: After only a few charging cycles the carbon electrode becomes corroded and the electrolytic fluid decomposes. "The problem was that no one knew exactly why," remarks Wandt.