Increasing sulfur utilization in lithium-sulfur batteries by a Co-MOF-74@MWCNT interlayer

• 作者: SiHyeon Sung Byung Hyuk Kim SeungTaek Lee Sanghyeon Choi Woo Young Yoon
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（9）
• 页码范围: 186-193
• 页数: 8页
• 语种: 英文

摘要

To improve lithium-sulfur battery performance,Co-MOF-74 has been applied for the first time as an interlayer with multiwalled carbon nanotubes(MWCNTs).Co-MOF-74@MWCNT was synthesized using a solvothermal method.The fabrication of Co-MOF-74@MWCNT was confirmed by scanning electron microscopy,X-ray diffraction,thermogravimetric analysis,and Brunauer-Emmett-Teller testing.The interlayer was fabricated using a filtration method.Assembled batteries were prepared using a Co-MOF-74@MWCNT interlayer and an MWCNT interlayer and subsequently investigated via cyclic voltam-metry tests.Co-MOF-74 promotes a redox reaction and shows a small peak at 1.85 V.A symmetric and full cell test revealed that the Co-MOF-74@MWCNT cell enables a faster redox reaction and higher capac-ity than that of the MWCNT cell.After 15 cycles,the Co-MOF-74@MWCNT cell achieved a value of 1112 mAh g-1,which is 26％greater than that of the MWCNT cell(880 mAh g-1)at 0.2C.Voltage profile testing showed that the reason for the higher capacity of the Co-MOF-74@MWCNT cell is that it promotes the conversion of Li2S2 to Li2S.Various electrochemical analyses confirmed that the Co-MOF-74@MWCNT interlayer acts not only as a physical and chemical barrier but also promotes the transformation of Li2S2 to Li2S.