Cobalt embedded in porous carbon fiber membranes for high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have received quite significant attention rooted from its ultra-high energy density. Nevertheless, the shuttle effect of dissoluble sulfurous intermediates is the primary obstacle which hinders their practical application. Herein, a porous carbon fiber membrane embedded with cobalt nanoparticles (Co-PCNF) was prepared by electrostatic spinning, then the active material was firmly fixed between the two layers of Co-PCNF to form a unique sandwich structure. With this strategy, an aluminum foil current collector can be replaced by the Co-PCNF sandwich structure, which is helpful to improve the energy density of Li-S battery as well as coordinate the volume change of sulfur in the process of charge and discharge, what's more, the shuttle effect is significantly inhibited. Results show that the as-assembled battery delivers an initial discharge specific capacities of 1013.3 mAh g(-1) and 933.4 mAh g(-1) at 0.5C and 1C, together with the decay rate of only 0.04% and 0.08% per cycle over 500 cycles, respectively. Moreover, the larger sulfur load (2.2 mg cm(-2)) still has the discharge specific capacity of 1009.8 mAh g(-1) after 150 cycles at 0.2C. This Co-PCNF sandwich electrode may provide a new idea for the structural design for Li-S batteries. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The use of a porous carbon fiber membrane embedded with cobalt nanoparticles has been shown to effectively address the shuttle effect in lithium-sulfur batteries, improving energy density and suppressing volume changes in sulfur. Experimental results demonstrate that batteries with this structural design exhibit stable performance and have promising potential for practical applications.