초록 |
Formation of soluble polysulfide (PS), which is a key feature of lithium sulfur (Li-S) battery, provides a fast redox kinetic based on liquid-solid mechanism, however, it imposes a critical problem of PS shuttle. Here, we address the dilemma by exploiting a solvent-swollen polymeric single ion conductor (SPSIC) as the electrolyte medium of Li-S battery. The SPSIC consisting of a polymeric single ion conductor and lithium salt-free organic solvents provides a Li ion hopping by forming a nanoscale conducting channel and suppresses PS shuttle according to Donnan exclusion principle when being employed for Li-S battery. The organic solvents at the interface of sulfur/carbon composite and SPSIC eliminate the poor interfacial contact, and function as a soluble PS reservoir for maintaining liquid-solid mechanism. Furthermore, the quasi-solid state SPSIC allows the fabrication of bipolar-type stack, which promise a realization of high voltage and energy dense Li-S battery. |