Chemical Science and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Nat Commun. 2013;4:2383. doi: 10.1038/ncomms3383.
The lithium-oxygen battery, of much interest because of its very high-energy density, presents many challenges, one of which is a high-charge overpotential that results in large inefficiencies. Here we report a cathode architecture based on nanoscale components that results in a dramatic reduction in charge overpotential to ~0.2 V. The cathode utilizes atomic layer deposition of palladium nanoparticles on a carbon surface with an alumina coating for passivation of carbon defect sites. The low charge potential is enabled by the combination of palladium nanoparticles attached to the carbon cathode surface, a nanocrystalline form of lithium peroxide with grain boundaries, and the alumina coating preventing electrolyte decomposition on carbon. High-resolution transmission electron microscopy provides evidence for the nanocrystalline form of lithium peroxide. The new cathode material architecture provides the basis for future development of lithium-oxygen cathode materials that can be used to improve the efficiency and to extend cycle life.
锂-氧电池因其非常高的能量密度而备受关注，但它也带来了许多挑战，其中之一是高充电过电位导致的效率低下。在这里，我们报告了一种基于纳米级组件的阴极结构，可将充电过电位显著降低至约 0.2 V。该阴极利用钯纳米粒子在具有氧化铝涂层的碳表面上的原子层沉积，以钝化碳缺陷部位。低充电电位是通过以下方式实现的：附着在碳阴极表面的钯纳米粒子、具有晶界的过氧化锂纳米晶体形式，以及氧化铝涂层防止电解质在碳上分解。高分辨率透射电子显微镜为过氧化锂的纳米晶体形式提供了证据。这种新型阴极材料结构为未来锂-氧阴极材料的发展提供了基础，可用于提高效率和延长循环寿命。
