Effective Stabilization of Long-Cycle Lithium-Sulfur Batteries Utilizing in Situ Prepared Graphdiyne-Modulated Separators

Lithium-sulfur batteries have been considered as the most competitive candidates for next generation of high energy density batteries. However, industrial application of such devices is still impeded by the transport of soluble lithium polysulfides (PSs). Herein, we reported the in situ preparation of graphdiyne nanosheets modulated on a commercial polypropylene separator to restrain the shuttle effect of PSs by enhanced physical adsorption and chemical binding with an in situ formed composite fence because of the strong interaction between the uniformly distributed acetylene bond and PSs. As a result, the batteries using a graphdiyne-modulated separator could deliver a higher initial capacity of more than 1262 mA h g^-1 at 0.1 C and a substantial capacity of 412 mA h g^-1 at 1 C after 500 cycles. In-depth analysis reveals that the facile strategy of the modulated separator with a rich acetylene bond and intermolecular pores is effective to enhance the physical absorption and chemical binding ability of PSs, which act as an in situ formed barrier layer to block the PSs for achieving high-energy batteries.