Carbon nanofibers implanted porous catalytic metal oxide design as efficient bifunctional electrode host material for lithium-sulfur battery

The shuttling effect of lithium polysulfides (LiPSs) and uncontrolled dendrite formation of metal lithium anode are the two critical obstacles hindering the commercial application of lithium-sulfur (Li-S) batteries. Herein, a bifunctional electrode host design consists of carbon nanofibers implanted ordered porous Co-decorated Al2O3 supported on carbon nanotube film (CNTF) is proposed to address these problems. As cathode sulfur host material, benefiting from the synergistic effect of porous Co-Al2O3 and the embedded CNFs, the CNFs/Co-Al2O3@CNTF exhibits excellent conductivity, efficient LiPSs confinement and catalytic conversion performance. It shows a high initial capacity of 1165 mAh g(-1) at 0.2 C, and holds a capacity of 594 mAh g(-1) even up to 3 C. When serves as anode, the CNFs/Co-Al2O3@CNTF electrode exhibits excellent Li+ diffusion performance and uniform lithium growth behavior, achieving a dendrite-free lithium electrode. The anode also shows good cycle stability during an ultra-long cycle time of 1000 h. A flexible pack cell assembled from CNFs/Co-Al2O3@CNTF electrodes delivers a specific capacity of 972 mAh g(-1) with capacity retention rate of 86.4% at 0.1 C.

Automated summary

In this study, a bifunctional electrode host design consisting of carbon nanofibers implanted ordered porous Co-decorated Al2O3 supported on carbon nanotube film (CNTF) was proposed to address the shuttling effect of lithium polysulfides (LiPSs) and dendrite formation of metal lithium anode in lithium-sulfur (Li-S) batteries. The electrode exhibited excellent conductivity, efficient confinement of LiPSs, and catalytic conversion performance, resulting in high initial capacity and good capacity retention during cycling. As an anode, the electrode showed excellent Li+ diffusion performance and uniform lithium growth behavior, achieving a dendrite-free lithium electrode. The flexible pack cell assembled from these electrodes delivered a specific capacity of 972 mAh g(-1) with good capacity retention.