Nature: remove the hidden danger of safety, new lithium battery can not use pure oxygen

Due to its high theoretical specific energy, lithium air battery is considered to be a promising alternative to lithium ion battery However, the lithium air battery studied so far is mainly used in pure oxygen environment (lithium oxygen battery), and its cycle life is very limited due to the side effects involving cathode, anode and electrolyte If nitrogen, carbon dioxide and water vapor exist, these side reactions will become more complicated In addition, due to the need to store oxygen, the bulk energy density of lithium-oxygen batteries may be too small in practical applications The characterization of the protected anode (source: nature) came from a research team led by Professor Amin Salehi khojin of Illinois State University, Chicago, USA, and Professor Larry A Curtiss of Argonne National Laboratory, who published a paper on the new lithium air battery (DOI: 10.1038 / nature25984) In this paper, a new battery system is reported, including an anode with a lithium carbonate protective layer, a molybdenum disulfide cathode, and an electrolyte mixed with DMSO and ionic liquid They work in a simulated air environment with a cycle life of up to 700 times They have a deep understanding of the operation of the system in this environment through calculation research This kind of lithium air battery, which works in the air like environment and has a long cycle life, is a key step to break through the technical bottleneck of lithium battery It is possible to obtain a much higher specific energy density than the traditional lithium-ion battery In previous studies, scientists have invented a new type of lithium battery, which can run in pure oxygen Because its energy theoretical calculation will be about 10 times that of ordinary lithium-ion batteries, it has been widely concerned, and obtained the admission certificate to become the next generation of new batteries Electric vehicles powered by lithium-oxygen batteries will be able to travel further after a single charge, because they can hold more energy than lithium-ion batteries of the same weight However, the nitrogen, carbon dioxide and water vapor in the air will react with the battery electrode to form sediment, so if air is used directly, the load capacity will be reduced rapidly Because oxygen is the only air component needed for electrochemical reactions in lithium air batteries, researchers used pure oxygen instead of air to deliver it to the batteries Although this eliminates the side effects, it is not practical for future applications It not only increases the storage space and weight of pure oxygen, but also makes the potential safety problems inevitable To solve this problem, Amin Salehi khojin team designed new electrodes and electrolytes The researchers deposited lithium carbonate and carbon on a lithium chip The coating allowed lithium ions to pass through, while preventing carbon dioxide, oxygen, nitrogen and water from contacting the highly active lithium on the electrode surface They used molybdenum disulfide nanoflakes to make cathodes to minimize the side effects at the cathodes In addition, the battery was filled with a mixture of DMSO and ionic liquid dissolved in lithium salt "The beauty of this design is that we can get all the benefits of pure oxygen while using air," said Salehi khojin, an electron micrograph of the cathode In the case of no protective layer, the battery will be scrapped after 11 charging cycles in the simulated air; while the battery system with the new design protective layer can run 700 charging cycles in the simulated air Corresponding author: Professor Amin Salehi khojin