From electric automobiles to high-speed phones, people are reliant on energy to power up advanced technology more than ever. As the world consumes more energy, scientists and industries are finding alternative energy sources that are safe, sustainable, and relatively inexpensive to operate. Currently, lithium-ion batteries (LIBs) dominant the battery market due to their reliability, long cycle life (>1000 cycles), and high volumetric energy density. However, someday lithium-sulfur batteries (LSBs) are potential candidates to replace LIBs due to their low cost, high theoretical capacity, and safety. Currently, the LSB market is at a standstill due to difficulties in solving the fast capacity degradation, the polysulfide “shuttling” effect, volume expansion, and short cycle life (<300 cycles). In this study, sulfur-carbon cathodes are fabricated via air-controlled electrospray, providing a facile, rapid, and evenly distributed coating on the cathode surface. Encapsulation of sulfur into Ketjen Black, a highly porous and electroconductive carbon material, provided a porous and electroconductive network. We proved the addition of reduced Graphene Oxide (rGO), as both a conductive carbon additive and layer, helped confine soluble polysulfides from diffusing between the cathode and anode with a layer-on-layer structure at high sulfur loading. We also demonstrated that increasing the carbon amount while decreasing the sulfur content in the composite cathode enhanced sulfur utilization by providing intimate contact between carbon and insulating sulfur. The failure mechanisms of air-controlled electrospray and slurry cast systems were also investigated to determine whether mass-transfer or surface-passivation cases at fast charging rates limited Li-S from reaching their full theoretical capacity. Both systems without a graphene layer showed that surface passivation caused the failure after a higher charge rate. However, the coating of the active material with a graphene layer proved that a higher charge rate failure was caused by mass-transfer limited case. To understand the relative diffusivity of the soluble polysulfides that form during a Li-S battery’s discharge rate, polysulfide diffusion through Celgard 2400 and a cross-linked gel polymer (TPTA-10%) coated separators was investigated via diffusion experiment. Numerical modeling and experiments showed that gelled polymer electrolyte helped entrap the polysulfide diffusion between the cathode and anode chambers and mitigate polysulfide shuttling effect.