Engineering n–p Heterointerfaces in Bi2Se3/Bi2O3 Nanocomposite Catalysts for Lithium–Oxygen Batteries

Lithium−oxygen batteries (LOBs) are considered promising candidates for next-generation energy storage systems due to their ultrahigh theoretical energy density. However, their practical application is challenged by sluggish reaction kinetics and unstable discharge product formation. Herein, we report the rational nanoscale engineering of a Bi2Se3/Bi2O3 heterostructured cathode via a controlled hydrothermal synthesis, addressing these limitations. The type-I band alignment in nanocomposite Bi2Se3/Bi2O3 generates a built-in electric field at the heterointerface, facilitating electron and ion transport and lowering the energy barriers for oxygen reduction (ORR) and evolution (OER) processes. Consequently, the Bi2Se3/Bi2O3 heterointerface catalyst exhibits exceptional specific capacity (19433.6 mAh g−1) and cycle stability (201 cycles at 200 mA g−1; 98 cycles at 1000 mA g−1), surpassing pristine Bi2Se3 by 320% in cycle life. This study establishes heterointerface engineering as a universal strategy for developing high-performance LOB catalysts.