| 초록 |
In the virtue of a high theoretical specific capacity of elemental sulfur (1,675 mAh g-1), and resulting high theoretical energy density of lithium-sulfur battery system (2,500 Wh kg-1), the lithium-sulfur (Li-S) battery has been regarded as the most promising battery that alternates current lithium-ion batteries (LIB). Despite the remarkable high energy density, the Li-S battery has obstacles of a low electrical conductivity of sulfur, a volume expansion of cathode durinhg cycles, and a dissolution of polysulfide which causes a loss of active material and a deterioration of lithium anode. A number of carbon materials have been introduced to mitigate those challenges such as porous carbons, CNTs, and graphene which can embed the sulfur in their porous matrix. Even though those carbon materials have been improved the reversible capacity and cyclability of Li-S battery with a high electrical conductivity and a suppression of polysulfide dissolution, the amount of active matarial loading has been limited below 2 mg cm-2. Herein, we introduced an electrospun carbon nanofiber (CNF) as a highly porous and electrically conductive reservoir for sulfur, which is easy to process and suitable for mass production. The fabricated CNF-sulfur electrode realized a high sulfur loading (＞10 mg cm-2) with a good reversible capacity (~700 mAh g-1). This result can be calculated as an areal capacity of ＞7 mAh cm-2 which surpasses that of recently reported lithium-ion batteries (1~3 mAh cm-2). |
