Encapsulated Monoclinic Sulfur for Stable Cycling of Li-S Rechargeable Batteriess

In the present investigation, we developed an encapsulated sulfur electrode. In the electrode design perspective, sulfur nanowires (NWs) were well aligned and completely covered by a minimal amount of carbon, and in the sulfur crystal structure perspective, a majority of sulfur adopts the uncommon monoclinic phase rather than the typical orthorhombic phase, after a heat treatment within a confi ned environment in nanometer dimensions. The electrode design in conjunction with the monoclinic crystal structure address all of the aforementioned issues and result in excellent electrical performance: a specifi c capacity reaching the theoretical value, substantial capacity retention over 1000 cycles, and rate capability with < 1 min discharge time were achieved.