(133d) Sequestration of Sulfur in Facilely Manufactured Carbon Nanospheres through Sulfur Recrystallization As an Effective PATH for LONG CYCLE Life of Lithium Sulfur Batteries

Lithium sulfur batteries are plagued by dissolution of sulfur into the electrolyte which gravely reduces their cycle life. Current strategies for retarding the negative fallout of the shuttle effect behavior experienced by lithium sulfur batteries, include attempts at trapping sulfur in various conductive carbonaceous matrices. In our work, we trap sulfur crystals in carbon nano-spheres through a facile synthesis technique to produces stable lithium sulfur cells with long lasting cycle life at C/10 rate. The trapping of the sulfur inside the sulfur nanospheres helps to delay the shuttle effect and protect the lithium anode from the negative effects of side reactions with sulfur polysulfides. Carbon nanospheres are constructed through a traditional carbonization of dextrose in the presence of dissolve sulfur. When the nanospheres are formed, sulfur is allowed to re-crystallize, and a coating of the finished material is utilized as the active cathode in the lithium sulfur cell. The formed material demonstrated its electrochemical suitability through studies of the electrochemical impedance of the cell as well as its cycle life. Formed cells show no demise of the high capacity of 850 mAh/g of sulfur over 150 cycles at a C/10 rate. We believe that confining the sulfur to nanospheres created in a sulfuric bath then allowing sulfur to recrystallize inside the sphere will slow down its dissolution into the polysulfide and extend the cycle life of the battery. The system will be optimized through varying the sulfur loading, crystal size, and carbon porosity as each variable contributes in our understanding of the stability displayed by the formed electrode