Chen Jing, Luo Yilin, Zhang Wenchao, Qiao Yu, Cao Xinxin, Xie Xuefang, Zhou Haoshen, Pan Anqiang, Liang Shuquan
School of Materials Science and Engineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.
Institute for Superconducting and Electronic Materials, School of Mechanical, Materials, Mechatronics and Biomedical Engineering, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW, 2500, Australia.
Nanomicro Lett. 2020 Aug 25;12(1):171. doi: 10.1007/s40820-020-00511-4.
MoSe/MoC/C multiphase boundaries boost ionic transfer kinetics. MoSe (5–10 nm) with rich edge sites is uniformly coated in N-doped framework. The obtained MoSe nanodots achieved ultralong cycle performance in LIBs and high capacity retention in full cell.
Interface engineering has been widely explored to improve the electrochemical performances of composite electrodes, which governs the interface charge transfer, electron transportation, and structural stability. Herein, MoC is incorporated into MoSe/C composite as an intermediate phase to alter the bridging between MoSe- and nitrogen-doped three-dimensional (3D) carbon framework as MoSe/MoC/N–C connection, which greatly improve the structural stability, electronic conductivity, and interfacial charge transfer. Moreover, the incorporation of MoC into the composites inhibits the overgrowth of MoSe nanosheets on the 3D carbon framework, producing much smaller MoSe nanodots. The obtained MoSe nanodots with fewer layers, rich edge sites, and heteroatom doping ensure the good kinetics to promote pseudo-capacitance contributions. Employing as anode material for lithium-ion batteries, it shows ultralong cycle life (with 90% capacity retention after 5000 cycles at 2 A g) and excellent rate capability. Moreover, the constructed LiFePO//MoSe/MoC/N–C full cell exhibits over 86% capacity retention at 2 A g after 300 cycles. The results demonstrate the effectiveness of the interface engineering by incorporation of MoC as interface bridging intermediate to boost the lithium storage capability, which can be extended as a potential general strategy for the interface engineering of composite materials. [Image: see text]
The online version of this article (10.1007/s40820-020-00511-4) contains supplementary material, which is available to authorized users.
MoSe/MoC/C多相边界促进离子转移动力学。富含边缘位点的MoSe（5 - 10纳米）均匀包覆在氮掺杂骨架中。所制备的MoSe纳米点在锂离子电池中实现了超长循环性能，在全电池中具有高容量保持率。
界面工程已被广泛研究以改善复合电极的电化学性能，其控制着界面电荷转移、电子传输和结构稳定性。在此，将MoC作为中间相引入到MoSe/C复合材料中，以改变MoSe与氮掺杂三维（3D）碳骨架之间的桥连，形成MoSe/MoC/N–C连接，这极大地提高了结构稳定性、电子导电性和界面电荷转移。此外，将MoC引入复合材料中抑制了MoSe纳米片在3D碳骨架上的过度生长，产生了更小的MoSe纳米点。所获得的层数较少、边缘位点丰富且有杂原子掺杂的MoSe纳米点确保了良好的动力学，以促进赝电容贡献。用作锂离子电池负极材料时，它表现出超长循环寿命（在2 A g下5000次循环后容量保持率为90%）和优异的倍率性能。此外，所构建的LiFePO//MoSe/MoC/N–C全电池在2 A g下300次循环后容量保持率超过86%。结果证明了通过引入MoC作为界面桥连中间体来增强锂存储能力的界面工程的有效性，这可扩展为复合材料界面工程的潜在通用策略。[图片：见原文]
本文的网络版本（10.1007/s40820-020-00511-4）包含补充材料，可供授权用户使用。
