Porous Mo 3 P/Mo Nanorods as Efficient Mott-Schottky Cathode Catalysts for Low Polarization Li-CO 2 Battery.

Li-CO 2 battery with high energy density has aroused great interest recently, large-scale applications are hindered by the limited cathode catalysis performance and execrably cycle performance. Herein, Mo 3 P/Mo Mott-Schottky heterojunction nanorod electrocatalyst with abundant porous structure is fabricated and served as cathodes for Li-CO 2 batteries. The Mo 3 P/Mo cathodes exhibit ultra-high discharge specific capacity of 10 577 mAh g -1 , low polarization voltage of 0.15 V, and high energy efficiency of up to 94.7%. Mott-Schottky heterojunction formed by Mo and Mo 3 P drives electron transfer and optimizes the surface electronic structure, which is beneficial to accelerate the interface reaction kinetics. Distinctively, during the discharge process, the C 2 O 4 2- intermediates combine with Mo atoms to form a stable Mo-O coupling bridge on the catalyst surface, which effectively facilitate the formation and stabilization of Li 2 C 2 O 4 products. In addition, the construction of the Mo-O coupling bridge between the Mott-Schottky heterojunction and Li 2 C 2 O 4 promotes the reversible formation and decomposition of discharge products and optimizes the polarization performance of the Li-CO 2 battery. This work provides another pathway for the development of heterostructure engineering electrocatalysts for high-performance Li-CO 2 batteries.