Three-dimensional carbon fiber as current collector for lithium/sulfur batteries

Ni foam and carbon fiber cloth were tested as three-dimensional (3D) current collectors for a sulfur/polypyrrole composite cathode in lithium batteries. The cell with the carbon fiber current collector has exhibited remarkably enhanced electrochemical performance compared with its Ni foam counterpart, delivering a high initial capacity of 1,278 mAh g^-1 and maintaining a discharge capacity at 810 mAh g^-1 after 40 cycles at 0.06 C. Furthermore, the carbon fiber-based cell demonstrated a better rate capability and delivered a highly reversible discharge capacity of 397 mAh g^-1 after 50 cycles at 0.5 C, representing an increase of 194 mAh g^-1 compared to the Ni foam counterpart. The electrochemical property investigations along with scanning electron microscope studies have revealed that the carbon fiber current collector possesses a three-dimensional network structure, provides an effective electron conduction path, and minimizes the loss of electrical contact within the deposited cathode material during cycling. These results indicate that the carbon fiber cloth can be used as a promising, effective, and inexpensive current collector for Li/S batteries.