Developing a highly effective interlayer inserted between the sulfur electrode and separator is one of the most important issues in Li–S battery research, because this interlayer enhances the cycle performance of the Li–S battery by trapping the lithium polysulfides in the sulfur electrode. Among various interlayer materials, carbon materials such as graphene and carbon nanotubes are particularly appealing because of their high electrical conductivity. Here, a new flexible carbon membrane interlayer consisting of graphene oxide (GO) and carbon nanotubes (CNTs) is developed by a facile vacuum filtration approach to trap the lithium polysulfides in the sulfur electrode. When the GO/CNT bilayer membrane is used as an interlayer between the sulfur electrode and separator (glass fiber), the Li–S battery delivers an initial discharge capacity of 1591.56 mAh g −1 and maintains a capacity of about 1000 mAh g −1 over 50 cycles at 0.2C with a low potential difference of 150 mV. This reflects higher electrochemical performance than a GO or CNT monolayer unilaterally. This is attributed to the hydrophilic functional group of the GO layer strongly adsorbing lithium polysulfides dissolved in liquid electrolyte and the CNT layer enhancing the ion conductivity.
Bibliographical noteFunding Information:
D.K.L., S.J.K., and Y.-J.K. contributed equally to this work. This research was supported by the Korea CCS R & D program funded by the Ministry of Science, ICT, and Future Planning (NRF-2014M1A8A1049297) and by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (NRF-2015K1A4A3047100). This research was also supported by a National Research Foundation of Korea (NRF) grant funded by the Ministry of Science, ICT, and Future Planning, Korea (NRF-2018R1A2B3008658) and by the Open Innovation Program of NNFC.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering