Yoon Ki Ro, Kim Dae Sik, Ryu Won-Hee, Song Sung Ho, Youn Doo-Young, Jung Ji-Won, Jeon Seokwoo, Park Yong Joon, Kim Il-Doo
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Department of Advanced Materials Engineering, Kyonggi University, Iui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 16227, Republic of Korea.
ChemSusChem. 2016 Aug 23;9(16):2080-8. doi: 10.1002/cssc.201600341. Epub 2016 Jul 25.
The development of efficient bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key issue pertaining high performance Li-O2 batteries. Here, we propose a heterogeneous electrocatalyst consisting of LaMnO3 nanofibers (NFs) functionalized with RuO2 nanoparticles (NPs) and non-oxidized graphene nanoflakes (GNFs). The Li-O2 cell employing the tailored catalysts delivers an excellent electrochemical performance, affording significantly reduced discharge/charge voltage gaps (1.0 V at 400 mA g(-1) ), and superior cyclability for over 320 cycles. The outstanding performance arises from (1) the networked LaMnO3 NFs providing ORR/OER sites without severe aggregation, (2) the synergistic coupling of RuO2 NPs for further improving the OER activity and the electrical conductivity on the surface of the LaMnO3 NFs, and (3) the use of GNFs providing a fast electronic pathway as well as improved ORR kinetics.
开发用于氧还原反应（ORR）和析氧反应（OER）的高效双功能催化剂是高性能锂氧电池的关键问题。在此，我们提出一种由用RuO2纳米颗粒（NPs）功能化的LaMnO3纳米纤维（NFs）和未氧化的石墨烯纳米片（GNFs）组成的非均相电催化剂。采用定制催化剂的锂氧电池具有优异的电化学性能，放电/充电电压差显著降低（在400 mA g(-1)时为1.0 V），并且具有超过320次循环的优异循环稳定性。出色的性能源于：（1）网络化的LaMnO3 NFs提供ORR/OER位点而无严重聚集；（2）RuO2 NPs的协同耦合进一步提高了LaMnO3 NFs表面的OER活性和电导率；（3）使用GNFs提供快速电子通路以及改善的ORR动力学。
