Investigating the catalytic effect of Nb2O5-x on sulfur cathodes in Li-S batteries

Lithium–sulfur (Li–S) batteries hold great promise due to their high theoretical energy density, but practical application remains limited by rapid capacity fading, polysulfide shuttling, and poor long-term stability. Transition metal oxides such as Nb2O5 have emerged as effective additives that can stabilize lithium polysulfides (LPS) and improve electrochemical reversibility. By probing the Nb K-edge, we can overcome this limitation and perform quantitative EXAFS analysis without interference. This experiment will allow us to resolve the local coordination environment, bond distances, and disorder around Nb atoms, providing crucial insights into how Nb2O5 accommodates structural changes during electrochemical cycling. The results will significantly advance the mechanistic understanding of Nb2O5 as an electrocatalytic promoter in Li–S systems.