Interface Engineering of Branched PdCoP <i> <sub>x</sub> </i> Nanostructures for High‐Performance Lithium–Oxygen Batteries
Zhiyuan Xu, Yu Zhang, Hong Yu, Zewen Zhuang, Xingdong Wang, Jiaqi Zhang, Xin Tan, Chang Chen, Chang Chen, Xin Chen, Qiuhua Yuan, Chen Chen, Chen Chen
Abstract
Abstract Developing advanced cathode materials plays a positive role in lowering the charge/discharge overpotentials and improving the cycling performance of lithium–oxygen batteries (LOBs). Here we report a direct synthesis strategy to prepare high‐dimensional branched PdCoP x series nanostructures, in which the Pd atoms are well dispersed within cobalt phosphide, leading to rich Pd─Co─P interfaces and evoking a prominent ligand effect between the elements. The Pd 1 Co 2 P x exhibits an excellent and stable activity for oxygen reduction reaction (ORR) in alkaline media, with a mass activity of 1.46 A mg Pd −1 , far exceeding that of commercial Pd/C (0.12 A mg Pd −1 ) and Pt/C (0.17 A mg Pt −1 ). Using Pd 1 Co 2 P x as the cathode, the resulting LOB shows an ultralow discharge/charge overpotential of 0.40 V and could run stably for over 240 cycles, which is a significant improvement compared with the counterparts using CoP x and Pd/C cathodes. Experimental and density functional theory (DFT) calculation results indicate that the dispersed Pd atoms could significantly enhance the ORR kinetics, and the Pd─Co─P interfaces could direct the two‐dimensional growth of Li 2 O 2 , thereby facilitating the formation of more easily decomposable film‐like Li 2 O 2 products. This feature successfully elevates both the charge and discharge performances, as well as the stability of the LOB.