Electrochemical properties of sulfurized poly-acrylonitrile (SPAN) cathode containing carbon fiber current collectors

Micro carbon fibers (CFs) as a current collector were coated on sulfurized poly-acrylonitrile (SPAN) electrodes fabricated by using electrostatic flocking method. The alignment and flocking density of CFs and the electrochemical properties of SPAN electrodes were investigated with various flocking parameters of flocking distance, length of CF, and loading weight. A long flocking distance gave a sufficient space to rotate charged CFs and stand CFs on the surface of electrodes during flocking process. The flocking density was increased with a decrease of milling time and the increase of loading weight. The current collectors flocked with 12 h-milled carbon fibers (CFs) exhibited less weight than Al current collector. SPAN electrodes with CF current collector demonstrated better electrochemical performance than that with Al current collector. In particular, SPAN electrodes flocked with a loading weight of 0.3 g showed stable cycleability (76% of capacity retention until 100th cycle) and good rate capability (930 mAh/g_sulfur at 2.0 C-rate).