The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.1, and stable cycling for more than 50 deep cycles at 0.1 C.

The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.1, and stable cycling for more than 50 deep cycles at 0.1 C.

The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.1, and stable cycling for more than 50 deep cycles at 0.1 C.

A method for preparing a nitrogen/sulfur-rich activated carbon, of exceptionally high surface area and microporous nature, the method comprising: preparing an aromatic oligomer including a heteroatom using an oxidative polymerization solution, wherein the oxidative polymerization solution comprises a first oxidizer and an organic solvent; mixing the oligomer with an activating agent to obtain a mixture; subjecting the mixture to carbonization and activation in a tube furnace; holding the mixture at a set temperature; cooling the mixture to room temperature to obtain a carbon material; purifying the carbon material by washing; washing the carbon material with water and methanol; drying the carbon material under vacuum to obtain a microporous carbon of high surface area and nitrogen/sulfur-rich composition.

A method for preparing a nitrogen/sulfur-rich activated carbon, of exceptionally high surface area and microporous nature, the method comprising: preparing an aromatic oligomer including a heteroatom using an oxidative polymerization solution, wherein the oxidative polymerization solution comprises a first oxidizer and an organic solvent; mixing the oligomer with an activating agent to obtain a mixture; subjecting the mixture to carbonization and activation in a tube furnace; holding the mixture at a set temperature; cooling the mixture to room temperature to obtain a carbon material; purifying the carbon material by washing; washing the carbon material with water and methanol; drying the carbon material under vacuum to obtain a microporous carbon of high surface area and nitrogen/sulfur-rich composition.

Systems and methods for converting methane and hydrogen sulfide to hydrogen and poly carbon subsulfide. An exemplary system includes a non-thermal plasma reactor, a first feed stream including methane, a second feed stream including hydrogen sulfide, a catalyst support material selected from boron nitride, carbon black, graphene, aluminum oxide (Al.sub.2O.sub.3) or titanium dioxide TiO.sub.2, and a catalyst selected from Ru, Rh, Ir, Pd, Pt, Re, Mo, Ni, Co, W and combinations thereof. An exemplary method includes providing a first feed stream including methane to a reactor, providing a second feed stream including hydrogen sulfide to the reactor, and reacting the first feed stream and the second feed stream in a non-thermal plasma in the presence of a catalyst to produce a product stream including hydrogen and poly carbon subsulfide.

Systems and methods for converting methane and hydrogen sulfide to hydrogen and poly carbon subsulfide. An exemplary system includes a non-thermal plasma reactor, a first feed stream including methane, a second feed stream including hydrogen sulfide, a catalyst support material selected from boron nitride, carbon black, graphene, aluminum oxide (Al.sub.2O.sub.3) or titanium dioxide TiO.sub.2, and a catalyst selected from Ru, Rh, Ir, Pd, Pt, Re, Mo, Ni, Co, W and combinations thereof. An exemplary method includes providing a first feed stream including methane to a reactor, providing a second feed stream including hydrogen sulfide to the reactor, and reacting the first feed stream and the second feed stream in a non-thermal plasma in the presence of a catalyst to produce a product stream including hydrogen and poly carbon subsulfide.