Hybrid of spinel zinc-cobalt oxide nanospheres combined with nitrogen-containing carbon nanofibers as advanced electrocatalyst for redox reaction in lithium/polysulfides batteries

The polysulfides shuttle effect and torpid kinetic are of the crucial barriers for lithium/sulfur batteries. Herein, nitrogen-containing carbon nanofibers (NCFs) combined with spinel zinc-cobalt oxide (ZCO) nanospheres hybrid (denoted as ZCONCFs) were designed as membrane electrode containing Li2S6 catholyte for lithium/polysulfides batteries, which promote electrochemical performance by suppressing the shuttle effect and enhancing the redox kinetics of lithium polysulfides. The conductive NCFs provide fast electronic transport and anchored ZCO nanospheres possess a strong affinity to sulfur species, which could effectively anchor lithium polysulfides, boost their redox reaction catalytically-accelerate the reversible soluble/insoluble phases conversion process, and greatly improve the utilization of active material. The results show that ZCONCFs membrane electrode with 5 mg sulfur loading exhibited stability cycling capacity and improved reaction kinetics, which delivered a high initial capacity of 1160 mAh g−1 at 0.2C and sustain a capacity of 830 mAh g−1 after 300 cycles. The cell with ZCONCFs exhibits 8.22 mAh under the sulfur loading of 10 mg and the capacity decay rate is 0.11% per cycle after 150 cycles. This effective method could significantly improve the application capacity of lithium/sulfur batteries.