Jo Changshin, Park Yuwon, Jeong Jooyoung, Lee Kyu Tae, Lee Jinwoo
†Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Korea.
‡School of Chemical and Biological Engineering, Seoul National University, Seoul, 151-744, Korea.
ACS Appl Mater Interfaces. 2015 Jun 10;7(22):11748-54. doi: 10.1021/acsami.5b03186. Epub 2015 May 28.
Ordered meso- or macro-porous carbons (OMCs) were applied as anodes in Na ion battery (NIB) systems. Three different block copolymers (BCPs) enabled us to control the pore sizes (6, 33, and 60 nm) while maintaining the same 2-D hexagonal structure. To exclude other effects, the factors including precursors, particle sizes, and degrees of graphitization were controlled. The structures of OMCs were characterized by nitrogen physisorption, Raman spectroscopy, X-ray analyses (XRD and SAXS), and microscopies (TEM and SEM). With a galvanostatic charge/discharge, we confirmed that OMC electrode with medium pore size (OMC-33) exhibited a higher reversible capacity of 134 mA h g(-1) (at 20th cycle) and faster rate capability (61% retention, current densities from 50 to 5000 mA g(-1)) than those of OMC-6, and OMC-60 electrodes. The high performance of OMC-33 is attributed to the combined effects of pore size and wall thickness which was supported by charge/discharge and electrochemical impedance spectroscopy (EIS) analyses.
有序介孔或大孔碳（OMCs）被用作钠离子电池（NIB）系统的阳极。三种不同的嵌段共聚物（BCPs）使我们能够在保持相同二维六方结构的同时控制孔径（6、33和60纳米）。为排除其他影响因素，对前驱体、粒径和石墨化程度等因素进行了控制。通过氮气物理吸附、拉曼光谱、X射线分析（XRD和SAXS）以及显微镜（TEM和SEM）对OMCs的结构进行了表征。通过恒电流充放电，我们证实中等孔径的OMC电极（OMC-33）在第20次循环时表现出134 mA h g(-1)的更高可逆容量以及比OMC-6和OMC-60电极更快的倍率性能（电流密度从50到5000 mA g(-1)时保持61%）。OMC-33的高性能归因于孔径和壁厚的综合作用，这得到了充放电和电化学阻抗谱（EIS）分析的支持。
