Boosting catalytic performance with bismuth for extended lifespan of light-assisted lithium-oxygen batteries

Photo-assisted Li-O2 batteries have gained significant attention due to their low overpotential. However, the rapid recombination of photogenerated carriers remains a fundamental challenge. Herein, we utilized a one-step hydrothermal method to produce bismuth nanoparticles and loaded bismuth/titanium dioxide/carbon nanotubes onto nickel foam (Bi/TiO2/CNTs/NF) by ultrasonic loading. Bismuth nanoparticles accelerate the transfer of photogenerated electrons and prolong the recombination of photogenerated carriers. As a result, photogenerated carriers act quickly and effectively at the three-phase reaction and interface. Carbon nanotubes (CNTs) and nickel foam (NF) increase the micropores and mesopores of the electrode for oxygen transport and lithium-oxygen storage. Increases the active sites of the electrodes while providing more storage space for the generated lithium peroxide. Accordingly, the photo-assisted Li-O2 battery with Bi/TiO2/CNTs/NF photocathode exhibits excellent multiplicity performance and good reversibility. The charging potential of Bi/TiO2/CNTs/NF was 0.22 V lower than TiO2/CNTs/NF and exhibited excellent cycle stability under illumination (Battery energy efficiency drops by only 6 % after 500 cycles)(Table S1, Supporting Information). This study provides a reference for developing and applying photocatalysts in photo-assisted Li-O2 batteries.