K2Mn4O8/Reduced Graphene Oxide Nanocomposites for Excellent Lithium Storage and Adsorption of Lead IonsChem. Eur. J. 2016, 22, 3397Shu-Meng Hao, Jin Qu,* Jing Yang, Chen-Xi Gui, Qian-Qian Wang, Qian-Jie Li, Xiaofeng Li, and Zhong-Zhen Yu*