Ketjen Black@Ce-MOF derived KB@CeO2-C as separator coating for lithium sulfur batteries

Lithium‑sulfur batteries (LSBs) have received wide attention because of their advantages of high theoretical specific capacity. However, shuttle effect of lithium polysulfides need to be solved urgently, which makes the commercial application of LSBs difficult. To solve these problems, Ce-MOF and conductive carbon material Ketjen Black (KB) are used to compound to obtain a composite precursor, and then further calcined at a high temperature to obtain KB@CeO2-C derivative. After applying KB@CeO2-C to commercial separators, the performance of LSBs is improved because of its excellent adsorption and catalytic capability. Through experimental analysis, when the sulfur areal density on the cathode electrode is 2.8 mg cm−1, the discharge specific capacity of the KB@CeO2-C separator battery in the first cycle at 0.5C is 835 mAh g−1, and after 900 cycles, the discharge specific capacity can still maintain 400.1 mAhg−1. When the sulfur loading of the electrode is added to 5 mg cm−1, the initial specific capacity at 0.1C can reach 1090.3 mAh g−1, and it can be stabilized for 120 cycles, which demonstrates its application potential. •KB@CeO2 is a composite of KB and Ce-MOF followed by calcination.•Application of KB@CeO2 composites to the modification of lithium-sulfur battery separators.•Nanorod-like CeO2 covered with KB particles can better promote polysulfide conversion.