Biomass derived Ni(OH)(2)@porous carbon/sulfur composites synthesized by a novel sulfur impregnation strategy based on supercritical CO2 technology for advanced Li-S batteries

The rational design and controllable synthesis of sulfur cathode with high sulfur content, superior structural stability and fascinating electrochemical properties is a vital step to realize the large-scale application of rechargeable lithium-sulfur (Li-S) batteries. However, the electric insulation of elemental sulfur and the high solubility of lithium polysulfides are two intractable obstacles to hinder the success of Li-S batteries. In order to overcome aforementioned issues, a novel strategy combined supercritical CO2 fluid technology and biotemplating method is developed to fabricate Ni(OH)(2) modified porous carbon microspheres as sulfur hosts to ameliorate the electronic conductive of sulfur and enhance simultaneously the physical and chemical absorptions of polysulfides. This elaborately designed Ni(OH)(2)@PYC/S composite cathode exhibits high reversible discharge capacity (1335 mAh g(-1) at 0.1 C), remarkable cyclic stability (602 mAh g(-1) after 200 cycles at 0.2 C) and superior rate capability, which is much better than its PYC/S counterpart. These results clearly demonstrate that the advanced porous carbon with good conductivity and the polar Ni(OH)(2) coating layer with strong trapping ability of polysulfides are responsible for the enhanced electrochemical performance.