Embedding MnO@Mn3O4 Nanoparticles in an N-Doped-Carbon Framework Derived from Mn-Organic Clusters for Efficient Lithium Storage

作者：Chu, Yanting; Guo, Lingyu; Xi, Baojuan; Feng, Zhenyu; Wu, Fangfang; Lin, Yue^*; Liu, Jincheng; Sun, Di^*; Feng, Jinkui; Qian, Yitai; Xiong, Shenglin^*

来源：Advanced Materials, 2018, 30(6): 1704244.

DOI：10.1002/adma.201704244

• anodes
• lithium-ion batteries
• Mn-8 clusters
• MnO@Mn3O4 nanoparticles
• nitrogen-doped porous carbon frameworks

The first synthesis of MnO@Mn3O4 nanoparticles embedded in an N-doped porous carbon framework (MnO@Mn3O4/NPCF) through pyrolysis of mixed-valent Mn-8 clusters is reported. The unique features of MnO@Mn3O4/NPCF are derived from the distinct interfacial structure of the Mn-8 clusters, implying a new methodological strategy for hybrids. The characteristics of MnO@Mn3O4 are determined by conducting high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and electron energy loss spectroscopy (EELS) valence-state analyses. Due to the combined advantages of MnO@Mn3O4, the uniform distribution, and the NPCF, MnO@Mn3O4/NPCF displays unprecedented lithium-storage performance (1500 mA h g(-1) at 0.2 A g(-1) over 270 cycles). Quantitative analysis reveals that capacitance and diffusion mechanisms account for Li+ storage, wherein the former dominates. First-principles calculations highlight the strong affiliation of MnO@Mn3O4 and the NPCF, which favor structural stability. Meanwhile, defects of the NPCF decrease the diffusion energy barrier, thus enhancing the Li+ pseudocapacitive process, reversible capacity, and long cycling performance. This work presents a new methodology to construct composites for energy storage and conversion.

• 出版日期2018-2-8
• 单位中国科学技术大学; 山东大学