초록 |
Lithium-sulfur batteries have a fatal disadvantage called as “polysulfide shuttle” which is caused by free diffusion of polysulfides dissolved in organic electrolyte. On the other hand, ion transport properties play a critical role to improve a device performance. Because it is related with electrochemical polarization issues, namely ohmic polarization called as IR drop and concentration polarization arises from a concentration gradient in the Li salt. Separator modification can solve polysulfide shuttle issue and furthermore, enhance ion transport properties. Here, it is required to maximize utilization of the surface-functionalized interface characteristics with zwitterions. To this end, surface of pore-controlled separator was grafted with sulfobetaine zwitterions. Ion transport properties were characterized through ionic conductivity, transference number and F, Li NMR data and polysulfide regulation issues and battery performance were evaluated in Li-S battery system. |