Novel Sulfur Host Composed of Cobalt and Porous Graphitic Carbon Derived from MOFs for the High-Performance Li-S Battery

作者：Lu, Yan-Qiu; Wu, Yi-Jin; Sheng, Tian; Peng, Xin-Xing; Gao, Zhen-Guang; Zhang, Shao-Jian; Deng, Li; Nie, Rui; Swiatowska, Jolanta; Li, Jun-Tao^*; Zhou, Yao; Huang, Ling; Zhou, Xiao-Dong; Sun, Shi-Gang

来源：ACS Applied Materials & Interfaces, 2018, 10(16): 13499-13508.

DOI：10.1021/acsami.8b00915

• lithium-sulfur batteries
• bimetallic metal-organic frameworks
• in situ UV/vis analysis
• cycle stability
• catalysis

A composite consisting of cobalt and graphitic porous carbon (Co@ GC-PC) is synthesized from bimetallic metal-organic frameworks and employed as the sulfur host for high-performance Li-S batteries. Because of the presence of a large surface area (724 m(2) g(-1)) and an abundance of macro-/mesopores, the Co@ GC-PC electrode is able to alleviate the debilitating effect originating from the volume expansion/contraction of sulfur species during the cycling process. Our in situ UV/vis analysis indicates that the existence of Co@GC-PC promotes the adsorption of polysulfides during the discharge process. Density functional theory calculations show a strong interaction between Co and Li2S and a low decomposition barrier of Li2S on Co(111), which is beneficial to the following Li2S oxidation in the charge process. As a result, at 0.2C, the discharge capacity of the S/Co@GC-PC cathode is stabilized at 790 mAh g(-1) after 220 cycles, much higher than that of a carbon-based cathode, which delivers a discharge capacity of 188 mAh g(-1).

• 出版日期2018-4-25
• 单位安徽师范大学; 厦门大学