One‐Step Route Synthesized Co₂P/Ru/N‐Doped Carbon Nanotube Hybrids as Bifunctional Electrocatalysts for High‐Performance Li–O₂ Batteries

Abstract

Abstract The large‐scale commercial application of lithium–oxygen batteries (LOBs) is overwhelmed by the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) associated with insoluble and insulated Li 2 O 2 . Herein, an elaborate design on a highly catalytic LOBs cathode constructed by N‐doped carbon nanotubes (CNT) with in situ encapsulated Co 2 P and Ru nanoparticles is reported. The homogeneously dispersed Co 2 P and Ru catalysts can effectively modulate the formation and decomposition behavior of Li 2 O 2 during discharge/charge processes, ameliorating the electronically insulating property of Li 2 O 2 and constructing a homogenous low‐impedance Li 2 O 2 /catalyst interface. Compared with Co/CNT and Ru/CNT electrodes, the Co 2 P/Ru/CNT electrode delivers much higher oxygen reduction triggering onset potential and higher ORR and OER peak current and integral areas, showing greatly improved ORR/OER kinetics due to the synergistic effects of Co 2 P and Ru. Li–O 2 cells based on the Ru/Co 2 P/CNT electrode demonstrate improved ORR/OER overpotential of 0.75 V, excellent rate capability of 12 800 mAh g −1 at 1 A g −1 , and superior cycle stability for more than 185 cycles under a restricted capacity of 1000 mAh g −1 at 100 mA g −1 . This work paves an exciting avenue for the design and construction of bifunctional catalytic cathodes by coupling metal phosphides with other active components in LOBs.