/ GRAPHENE OXIDE AS A SULFUR IMMOBILIZER IN HIGH PERFORMANCE LITHIUM/SULFUR CELLS

摘要

The loss of sulfur cathode material resulting from polysulfide dissolution leads to significant capacity fading in rechargeable lithium / sulfur cells. Embodiments of the invention use chemical approaches to immobilize sulfur and lithium polysulfides through reactive functional groups on graphene oxide. This approach results in homogeneous and thin (~ several tens of nanometers) sulfur coatings on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature heat treatment process. Strong interactions between graphene oxide and sulfur or polysulfides indicate lithium / sulfur cells with stable cycling for more than 50 dip cycles at 0.1 C and high reversible capacities of 950-1400 mAh g ^-1 .