High-content of sulfur uniformly embedded in mesoporous carbon: a new electrodeposition synthesis and an outstanding lithium-sulfur battery cathode

We report a novel synthesis of a mesoporous carbon-sulfur composite (MCSC) by electrodeposition of sulfur into the mesopores via a self-limiting process. With the merits of a high sulfur content (77%), uniform distribution and strong C-S bonds achieved by this method, the as-prepared materials demonstrate excellent performance in lithium-sulfur batteries. The electrode delivers high specific capacities at various C-rates (e.g. about 1160 and 590 mA h g^-1 at current densities of 0.1 and 2.0 A g^-1, respectively) and remarkable capacity retention, remaining above 857 mA h g^-1 after 200 cycles at a high rate of 0.5 A g^-1. This electrochemical strategy is industrially viable and scalable, and thus may pave a new way to push the commercialization of Li-S batteries.