Intrinsic stabilization of vacancies in catalysts via high-entropy approach for lithium-sulfur batteries

ABSTRACT Oxygen vacancies (VO) have been considered as a significant strategy to improve the performance of catalysts in Li-S batteries. However, the highly active VO are a double-edged sword, as their instability can undermine long-term cycle performance. Therefore, it is essential to stabilize VO while maintaining their high activity. Here, five different metal elements are dissolved into the lattice structure of two-dimensional oxides to construct intrinsically stable and active VO for better lithium-sulfur catalysts. The unique electronic and crystal structure in high-entropy oxide endows the changed differentiated formation energies and high diffusion energy barrier of VO to form intrinsically stable VO. The Li-S batteries with stable VO in the electrocatalyst deliver a high specific capacity of 1301 mAh g−1 at 0.2C and low capacity fading of 0.032% per cycle after 2000 cycles at 1C. This work will inspire efforts on breaking the trade-off between activity and stability in heterogeneous catalysis beyond Li-S batteries.