Surface Phosphatization for a Sawdust‐Derived Carbon Catalyst as Kinetics Promoter and Corrosion Preventer in Lithium–Oxygen Batteries

Abstract

Abstract Strong oxidant intermediates and the formation of byproducts during the discharge/charge process are the main challenges in the degradation of lithium–oxygen batteries (LOBs). A facile approach to maintain the stability of the cathode catalyst and avoid the formation of byproducts is essential for the development of LOBs. Here, a sawdust‐derived carbon catalyst is fabricated and subjected to surface phosphatization to suppress corrosion between carbon and electrolyte/products. This prevents the formation of byproducts from parasitic reactions and boosts the reaction kinetics of the carbon catalyst in LOBs. The doped P atoms will prior to substitute an N atom in pyrrolic‐N sites to form graphitic PN sites, instead of the graphitic PC sites. Experimental and density functional theory calculations reveal that the graphitic PN sites can function as a reaction kinetics promoter for the formation/decomposition of discharge products. Moreover, the graphitic PN sites can also prevent the formation of byproduct Li 2 CO 3 from the corrosion of the carbon catalyst, despite its poor catalytic capability in LOBs. As a result, the sawdust‐derived P‐doped catalyst exhibits an enhanced specific capacity of ≈20 000 mAh g –1 and long cycle stability of 226 and 160 cycles at 200 and 500 mA g –1 , respectively.