Efficient polysulfide shuttle mitigation by graphene-lithium cobalt vanadate hybrid for advanced lithium-sulfur batteries

Polysulfide shuttle is a major challenge to be addressed while designing lithium-sulfur batteries (LSBs) as it stagnates the overall performance of the system. The exploration of better material combinations is imperative to deal with the issue. With this objective, a grain-like lithium cobalt vanadate embedded graphene nanoplatelets (GLCVO) is designed as a potent sulfur host in Li-S batteries. The composite cathode with preferable active sites is found to be highly efficacious in capturing the polysulfides through strong chemical interaction as well as propelling the polysulfide conversion reaction kinetics. Furthermore, the graphene nanoplatelets render an interconnected pathway for electronic conduction. As a direct consequence, the GSLCVO cell evinces an initial discharge capacity of 982 mAh g(-1) at 0.5 C rate and maintains excellent cyclability with a low attenuation rate of 0.031% over 800 cycles. Besides, the cell exhibits better static stability and attenuates the self-discharge behavior to a great extent. The detailed structural and electrochemical evaluation cooperatively reveals its excellent electrochemical properties which makes it an attractive cathode material for LSBs.

Automated summary

The GLCVO composite cathode effectively addresses the polysulfide shuttle issue in lithium-sulfur batteries, enhancing the conversion reaction kinetics and capture efficiency of polysulfides. The graphene nanoplatelets provide a pathway for electronic conduction, leading to excellent cycling performance and reduced self-discharge of the GSLCVO cell.