Cobalt/three-dimensional carbon/reduced graphene oxide modified PP separator for Li-S batteries

Abstract

In this work, a composite of cobalt metal nanoparticles/three-dimensional carbon/reduced graphene oxide (Co-3DC-rGO) was synthesized using corn husk, ZIF-67, and graphene oxide as precursors. The Co-3DC-rGO was used to modify commercial PP to prepare the Co-3DC-rGO/PP separator. The performance of Co-3DC-rGO/PP separator was evaluated in lithium-sulfur batteries (LSBs). SEM images exhibited that a three-dimensional carbon (3DC) skeleton was obtained by corn husk transformation, and the ZIF-67-derived cobalt-decorated carbon dodecahedrons were homogeneously filled into the hierarchical pores of the 3DC structure. TEM images displayed that Co metal nanoparticles can escape from ZIF-67 and scatter on the rGO nano-sheets and 3DC skeleton. Benefitting from the synergy effects of the 3D carbon skeleton, rGO, and Co metal nanoparticles, the electrochemical performance of LSBs with Co-3DC-rGO/PP separator is better than LSBs with commercial PP separator. When tested at 1C, the LSB with Co-3DC-rGO/PP separator presents a high stable reversible capacity of 516.3 mA h g −1 after 500 cycles. This research provides new ideas for the preparation of LSBs separator. • Co/3D carbon/rGO decorated PP separator was prepared and used in Li-S batteries. • Co/3D carbon/rGO can inhibit the shuttle of lithium polysulfides to the Li anode. • Co/3D carbon/rGO accelerate the conversion of lithium polysulfides to Li2S. • The Li-S battery with Co/3DC/rGO/PP separator delivers excellent electrochemical performance.