Monometallic Pd Loaded on N-CNTs by Seed Growth Method as an Efficient Catalyst for Li-O2 Battery

Abstract

The enormous potential for polarization and poor cycling performance of the cathode restrains the commercial application of Li-O₂ batteries. Therefore, designing effective cathode catalysts for high-performance Li-O₂ batteries is crucial. In this study, nitrogen-doped carbon nanotubes (N-CNTs) modified with ultra-low loading cubic monometallic palladium particles (mPd/N-CNTs) were used as the cathode catalyst for the Li-O₂ batteries. The spray pyrolysis chemical vapor deposition method synthesized N-CNTs that have a special open 3D multi-channel structure that benefits the three-phase reaction interface and promotes the deposition/decomposition of thin-film Li₂O₂. In addition, the seed growth method synthesized high-efficiency catalytic activity of cubic monometallic Pd nanoparticles that encourages the decomposition of discharge products. Hence, the Li-O₂ batteries utilize mPd/N-CNTs as cathode catalysts to deliver a large discharge specific capacity of 11.79 mAh cm⁻², low overpotential (0.93 V), and an ultralong cycling life of 400 cycles/4800 h. Overall, this study provides a feasible idea for designing efficient and stable bifunctional catalysts with ultra-low loading of precious metal, which could have significant implications for developing high-performance Li-O₂ batteries.