标题：Template-free fabrication of graphene-wrapped mesoporous ZnMn2O4 nanorings as anode materials for lithium-ion batteries
作者：Zhou, Weiwei; Wang, Dong; Zhao, Limin; Ding, Chunyan; Jia, Xingtao; Du, Yu; Wen, Guangwu; Wang, Huatao
作者机构：[Zhou, Weiwei; Zhao, Limin; Jia, Xingtao; Du, Yu; Wen, Guangwu; Wang, Huatao] Harbin Inst Technol, Sch Mat Sci & Engn, Weihai 264209, Peoples R China. 更多
通讯作者：Zhou, WW;Wang, HT
通讯作者地址：[Zhou, WW; Wang, HT]Harbin Inst Technol, Sch Mat Sci & Engn, Weihai 264209, Peoples R China.
关键词：ZnMn2O4; graphene; lithium ion battery; nanorings
摘要：We rationally designed a facile two-step approach to synthesize ZnMn2O4@ G composite anode material for lithium-ion batteries (LIBs), involving a template-free fabrication of ZnMn2O4 nanorings and subsequent coating of graphene sheets. Notably, it is the first time that ring-like ZnMn2O4 nanostructure is reported. Moreover, our system has been demonstrated to be quite powerful in producing ZnMn2O4 nanorings regardless of the types of Zn and Mn-containing metal salts reactants. The well-known inside-out Ostwald ripening process is tentatively proposed to clarify the formation mechanism of the hollow nanorings. When evaluated as anode material for LIBs, the resulting ZnMn2O4@ G hybrid displays significantly improved lithiumstorage performance with high specific capacity, good rate capability, and excellent cyclability. After 500 cycles, the ZnMn2O4@ G hybrid can still deliver a reversible capacity of 958 mAh g(-1) at a current density of 200 mA g(-1), much higher than the theoretical capacity of 784 mAh g(-1) for pure ZnMn2O4. The outstanding electrochemical performance should be reasonably ascribed to the synergistic interaction between hollow and porous ZnMn2O4 nanorings and the threedimensional interconnected graphene sheets.