A ZIF-67-derived-sulfur sandwich structure for high performance Li-S batteries

Herein, a novel ZIF-67-derived material, PZ67, is developed as an effective coating to construct a sandwich-structured electrode for high performance lithium sulfur batteries. Taking advantage of the synergistic effect of chemical interaction, physical barrier, and high conductivity of PZ67 coatings, we found that the PZ67/S/PZ67 structured cathode can effectively enhance the active materials reaction kinetics, prohibit the shuttling effect, and improve the batteries' cycling performance, achieving a superior electrochemical performance. It delivers an initial capacity of 1158.1 mA h g^-1 and retains at 715 mA h g^-1 after 300 cycles, which is more than twice of that of a bare sulfur-based cell. Even at the current density of 1 C, the discharge capacity still approaches 916.7 mA h g^-1.