Abstract:
The synthesis of highly porous carbon (HPC) materials from poplar catkin by KOH
chemical activation and hydrothermal carbonization as a conductive additive to a lithium-sulfur
cathode is reported. Elemental sulfur was composited with as-prepared HPC through a melt diffusion
method to form a S/HPC nanocomposite. Structure and morphology characterization revealed a
hierarchically sponge-like structure of HPC with high pore volume (0.62 cm3 g1) and large specific
surface area (1261.7 m2 g1). When tested in Li/S batteries, the resulting compound demonstrated
excellent cycling stability, delivering a second-specific capacity of 1154 mAh g1 as well as presenting
74% retention of value after 100 cycles at 0.1 C. Therefore, the porous structure of HPC plays an
important role in enhancing electrochemical properties, which provides conditions for effective
charge transfer and effective trapping of soluble polysulfide intermediates, and remarkably improves
the electrochemical performance of S/HPC composite cathodes.