Efficient Polysulfide Shuttle Mitigation by Graphene-Lithium Cobalt Vanadate Hybrid for Advanced Lithium-Sulfur Batteries
Chemistry
The modern society and recent scientific developments inextricably depend on the effective energy storage systems. Lithium-sulfur battery (LSB) received the attention of researchers due to its high theoretical capacity of 1675 mAh g-1 through the electrochemical reaction between lithium and sulphur. Polysulfide shuttle is a major challenge to be addressed while designing 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 LSBs. The composite cathode with preferable active sites is found to be highly efficacious in capturing the polysulfides through strong chemical interaction. Simultaneously, GLCVO composite with intrinsic catalytic property propels the polysulfide conversion reaction kinetics. Furthermore, the graphene nanoplatelets render an interconnected pathway for electronic conduction. As a direct consequence, the fabricated coin 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 500 cycles. Besides, the cell exhibits better static stability and attenuates the self-discharge behaviour 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.
Fig. (a) Schematic illustration of the polysulfide confinement mechanism in GSLCVO cell; (b) CV curves of GS and GSLCVO cells; (c) initial charge-discharge profiles of GS and GSLCVO cells at 0.1 C; (d) Long-term cycling performances of GSLCVO cell at 0.5 C.
Ref: Sreekala K., Haritha H., Mary Gladis J., Efficient polysulfide shuttle mitigation by graphene-lithium cobalt vanadate hybrid for advanced lithium-sulfur batteries, J. Electroanal. Chem. 899 (2021) 115665. https://doi.org/10.1016/j.jelechem.2021.115665.
