Yanan Chen, Qiang Zhang, Zhang Zhang, Xianlong Zhou, Yiren Zhong, Mei Yang, Zhaojun Xie, Jinping Wei, Zhen Zhou*, 
Two Better Than One: Cobalt-Copper Bimetallic Yolk-Shell Nanoparticles Supported on Graphene as Excellent Cathode Catalysts for Li-O2 Batteries, 
J. Mater. Chem. A (accepted, IF=7.443).