Department of Chemical and Environmental Engineering, Yale University , 9 Hillhouse Avenue, New Haven, Connecticut 06520, United States.
Nano Lett. 2015 Jan 14;15(1):434-41. doi: 10.1021/nl503760n. Epub 2014 Dec 30.
Controlling the mesoscale geometric configuration of catalysts on the oxygen electrode is an effective strategy to achieve high reversibility and efficiency in Li-O2 batteries. Here we introduce a new Li-O2 cell architecture that employs a catalytic polymer-based membrane between the oxygen electrode and the separator. The catalytic membrane was prepared by immobilization of Pd nanoparticles on a polyacrylonitrile (PAN) nanofiber membrane and is adjacent to a carbon nanotube electrode loaded with Ru nanoparticles. During oxide product formation, the insulating PAN polymer scaffold restricts direct electron transfer to the Pd catalyst particles and prevents the direct blockage of Pd catalytic sites. The modified Li-O2 battery with a catalytic membrane showed a stable cyclability for 60 cycles with a capacity of 1000 mAh/g and a reduced degree of polarization (∼ 0.3 V) compared to cells without a catalytic membrane. We demonstrate the effects of a catalytic membrane on the reaction characteristics associated with morphological and structural features of the discharge products via detailed ex situ characterization.
控制催化剂在氧电极上的介观几何构型是实现 Li-O2 电池高可逆性和高效率的有效策略。在这里，我们引入了一种新的 Li-O2 电池结构，在氧电极和隔膜之间采用催化聚合物膜。催化膜是通过将钯纳米颗粒固定在聚丙烯腈（PAN）纳米纤维膜上并与负载 Ru 纳米颗粒的碳纳米管电极相邻而制备的。在氧化物产物形成过程中，绝缘的 PAN 聚合物支架限制了电子向 Pd 催化剂颗粒的直接转移，并防止了 Pd 催化位点的直接堵塞。与没有催化膜的电池相比，具有催化膜的改性 Li-O2 电池在 60 次循环中具有稳定的循环性能，容量为 1000 mAh/g，极化度降低（约 0.3 V）。我们通过详细的非原位表征证明了催化膜对与放电产物形态和结构特征相关的反应特性的影响。
