Lithium sulfur batteries (LSBs) are a promising candidate to be used in modern commodities like electric vehicles, grid energy storage, electric aviation, and many others because of the exceptionally high theoretical capacity of sulfur (1675 mAh g^-1), almost 5 times higher than the conventional lithium-ion batteries. However, the problem of polysulfide shuttling effect originating from the dissolved lithium polysulfides in the electrolyte results in poor cycling stability, hindering the commercialization of LSB. Significant advancement has been made over the years due to a great deal of research on novel materials development and structural design for lithium polysulfide (Li₂S_n: 4≤ n ≤8) adsorption synergy to counter the polysulfide shuttling effect ¹. However, rather than focusing only on the adsorption synergy (Physical confinement and chemical binding), novel catalysts that can accelerate the polysulfide conversion reaction kinetics are needed to design the next generation LSB. Previously, our group investigated shape-controlled cerium oxide (CeO₂) to accelerate the polysulfide conversion reactions by generating the intermediate steps of thiosulfate and polythionate ^{2, 3}. Copper oxide (CuO), being a p-type semiconducting material, is another promising material that can activate thiosulfate formation as its redox potential is 2.53 V vs Li/Li⁺, which lies in the potential window of 2.4 V < E° ≤ 3.05 V that selectively triggers the formation of thiosulfate. Herein, we investigated 10 wt% of CuO impregnated on the CeO₂ nanorods (10 wt%CuO/CeO₂) as a cathode host for LSB. The CuO impregnation on the surface of CeO₂ nanorods attributed strong interaction between the surface defect rich CeO₂ nanorods and the copper oxides (CuO_x: Cu₂O and CuO) promoting excellent electrocatalytic activity. The 10 wt%CuO/CeO₂ sample provides adsorption-catalysis dual synergy to chemically bind and further catalyze the polysulfide conversion by polythionate and thiosulfate generation. As a result, the derived LSB exhibited excellent electrochemical performance with high capacity of 1141 mAh g^-1 at 0.2 C with a sulfur loading of 1.33 mg cm^-2 and a capacity loss of only 0.04% per cycle after 60 cycles.

Key words: lithium sulfur batteries, lithium polysulfides, shuttle effect, cerium oxide, catalysis.

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